Publications

Altaee, A, Zhou, J, AlAnezi, AA & Zhao, G 2017, 'The design and optimization for a closed-loop pressure retarded osmosis process' in Julian E. Perez, JE (ed), Energy Efficiency: Performance, Improvement Strategies and Future Directions, Nova, New York, pp. 65-89.
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Pressure Retarded Osmosis (PRO) is an emerging renewable energy technique with potential for scale up and commercialization. It has been extensively investigated in the last decade as a new technique for power generation from osmotic energy. Both open-loop and closed-loop PRO have been suggested for power generation, differing in that the draw and feed solutions are disposed of after membrane treatment in the open-loop PRO process. The closed-loop PRO (CLPRO) process operates like a heating engine in which the diluted draw solution enters a special unit after leaving the membrane for regeneration and reuse. CLPRO uses a pure draw solution for process operation, hence reducing membrane fouling and cleaning requirements. Furthermore, there is no waste discharge to the environment and no pretreatment is required for the feed solution. CLPRO design requires optimizing the operating parameters to reduce the capital and operating costs of the process. Membrane area, feed pressure, draw solution, and draw solution flow rate are among the key operating parameters that significantly impact CLPRO performance. A computer model is developed in the current study to evaluate the impact of these parameters on CLPRO performance. The feed solution osmotic pressure was considered to be negligible because of the high purity of water produced from the regeneration unit. Simulation results revealed that feed pressure is the most influential parameter on the CLPRO performance, followed by the draw solution flow rate and membrane area. In fact, the membrane impact on the performance of CLPRO did not exceed 4%. The result of this study should be considered in the early stages of CLPRO design to reduce operating and capital costs.

Chaudhuri, G, Roy, R, Chandrasekaran, N & Mukherjee, A 2017, 'Bacteria-and Algae-Mediated Remediation of Chromium' in Handbook of Metal-Microbe Interactions and Bioremediation, CRC Press, USA, pp. 707-717.
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Cr(VI) and Cr(III) are the two most ubiquitous forms of chromium. The remediation of chromium contaminant is primarily dependent on transformation from highly toxic and mobile Cr(VI) to insoluble Cr(III) with less toxicity. Biological Cr(VI) removal is not only a promising method but also a very complicated process. This chapter introduces various remediation processes, highlights important Cr(VI)-reducing microorganisms, and reveals underlying mechanisms for bacterial Cr(VI) resistance and reduction. The assessment of key factors limiting and influencing bacterial growth and chromium removal along with reviews on mathematical modeling tended to facilitate further application of microbial Cr(VI) removal in the bench scale, pilot scale, and in situ studies under a wide array of environmental conditions.

Jeong, S, Naidu, G, Leiknes, T & Vigneswaran, S 2017, '4.3 Membrane Biofouling: Biofouling Assessment and Reduction Strategies in Seawater Reverse Osmosis Desalination' in Comprehensive Membrane Science and Engineering, Elsevier, pp. 48-71.
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This article aims to elucidate the important issues associated with biofouling and the use of pretreatment systems for biofouling control. The focus here is on the various factors in fluencing the formation of biofouling on reverse osmosis(RO)membranes(or biofouling potential). This article also highlights the need for an indicator to assessmicrobial contamination in seawater. Specific techniques on sea water characterization methods and biofouling indicator areal so presented.

Kumar, M, Kuzhiumparambil, U, Ralph, PJ & Contreras-Porcia, L 2017, 'Polyamines' in Algal Green Chemistry, Elsevier, pp. 243-255.
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© 2017 Elsevier B.V. All rights reserved. Marine macrophytes including seaweeds and sea grasses are the ecosystem engineers and experience constant threats from a wide range of anthropogenic stressors and climate fluctuations in their ecological niche. Marine macrophytes acclimate and/or tolerate these external perturbations by reprogramming their metabolite networks. Among the various metabolites that contribute to alleviate the stress, polyamines (PAs) are the nitrogenous metabolites that play a key role in plant growth, development, and biotic/abiotic stress protection in land plants. Their mode of action, signaling, and cross talk with diverse metabolic networks have been well studied in land plants; however, their functionality in marine macrophytes has merely scratched the window. In this brief chapter we attempt to summarize PA research in marine macrophytes in response to abiotic stress conditions. We emphasize to undertake futuristic efforts to explore PA involvement in stress response and to identify novel stress tolerance mechanism in marine macrophytes.

Kuzhiumparambil, U, Kumar, M & Ralph, P 2017, 'Gas and Liquid Chromatography-Mass Spectrometry-Based Metabolic Profiling of Marine Angiosperm Zostera muelleri (Alismatales, Zosteraceae)' in Systems Biology of Marine Ecosystems, Springer International Publishing, pp. 189-203.
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© Springer International Publishing AG 2017. Seagrasses are monocotyledonous marine flowering plants that are considered lungs of the sea and are the most intense carbon sinks on the planet, delivering a range of ecologically and economically valuable biological services. In this study, we report the chemical fingerprint of Zostera muelleri using an untargeted metabolomic approach. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS) were performed to study the metabolic profile of Z. muelleri. A total of 98 metabolites belonging to various chemical classes including flavonoids, phenolics, lipids, fatty acids, sugar alcohols and amino acids were identified, including two characteristic marker compounds of the genus, zosteric acid and rosmarinic acid. Chromatographic profiling yield a comprehensive map for the chemical constituents of Z. muelleri, and this method can be used as an effective and convenient approach to gain insights into the chemical composition of other seagrasses.

Lee, DJ, Hallenbeck, PC, Ngo, HH, Jegatheesan, V & Pandey, A 2017, 'Preface', pp. xxi-xxii.
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Lee, D-J, Hallenbeck, PC, Ngo, HH, Jegatheesan, V & Pandey, A 2017, 'Preface' in Current Developments in Biotechnology and Bioengineering, Elsevier, pp. xxi-xxii.
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Mofijur, M, Rasul, MG, Hassan, NMS, Masjuki, HH, Kalam, MA & Mahmudul, HM 2017, 'Assessment of Physical, Chemical, and Tribological Properties of Different Biodiesel Fuels' in Clean Energy for Sustainable Development, Elsevier, pp. 441-463.
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Fuel properties of biodiesels are influenced by the physical features of the fatty acid composition, such as the degree of unsaturation, the percentage of saturated fatty acid, monounsaturated fatty acid, and polyunsaturated fatty acid. Fuel properties are the key factors in determining the suitability of any fuel as an alternative fuel. In this study, biodiesels from five different feedstocks have been characterized for their physical and chemical properties. Gas chromatography has been carried out to find out the ester composition of these five biodiesels, and correlation between composition and fuel properties of these five biodiesels have been developed. Fuel properties were measured according to standard procedure ASTM D6751 and EN 14214 and estimated based on the previously published correlation. Also, the quality of these biodiesels was assessed and compared with commercially available biodiesels through multivariate data analysis using PROMETHEE-GAIA software. In the last part, wear and friction of selected biodiesel fuels have been studied and compared with diesel fuel. The result shows that the properties of produced biodiesel are within the acceptable limit of ASTM and EN standards. Highly linear correlations were found between the composition and cetane number, iodine value, oxidation stability, and cold flow plugging point with the regression value of 0.9965, 0.9983, 0.7044, and 0.9985, respectively. Overall, this study found that, among the biodiesels studied, the palm biodiesel was the most suitable alternative followed by the macadamia, moringa, and jatropha, and beauty leaf biodiesel.

Mujtaba, IM, Srinivasan, R & Elbashir, NO 2017, 'The Water-Food-Energy Nexus' in Mujtaba, IM, Srinivasan, R & Elbashir, NO (eds), The Water-Food-Energy Nexus: Processes, Technologies, and Challenges, CRC Press, pp. 56-68.
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© 2018 by Taylor & Francis Group, LLC. After air, water is the most essential commodity for all living beings on the earth. Quality water and quality life go hand in hand. The food we eat, the houses we live in, the transports we use, and the things we cannot do without in 24/7/365 determine our quality of life and require sustainable and steady water supplies (IChemE Technical Roadmap, 2007).

Nghiem, LD, Hai, FI, Price, WE, Wickham, R, Ngo, HH & Guo, W 2017, 'By-products of Anaerobic Treatment' in Current Developments in Biotechnology and Bioengineering, Elsevier, THe Netherlands, pp. 469-484.
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© 2017 Elsevier B.V. All rights reserved.Anaerobic digestion is a widely used and probably the most sustainable technique for biogas production and nutrient recovery from manure. This chapter describes the process of anaerobic digestion of manure and other cosubstrates with a specific focus on biogas and digestate utilization. Biogas purification is one of the most significant bottlenecks to fully realizing the range of biogas utilization for not just energy production but also other forms of beneficial usages. Thus, biogas purification techniques are discussed in detail in this chapter. Digestate from manure is an excellent biofertilizer and can be applied using the same equipment designed for liquid fertilizer. Previous studies corroborated in this chapter highlight the importance of quality control and digestate application practice particularly when manure is codigested with other cosubstrates or the digestate is used on a different farm.

Ngo, HH, Guo, W, Tram Vo, TP, Nghiem, LD & Hai, FI 2017, 'Aerobic Treatment of Effluents From the Aquaculture Industry' in Ngo, HH (ed), Current Developments in Biotechnology and Bioengineering, Elsevier, UK, pp. 35-77.
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© 2017 Elsevier B.V. All rights reserved. The rapid development of aquaculture that is diverse in character brings more challenges for water resource management. Discharges from all aquaculture systems can be characterized by a high concentration of nutrients. This raises concerns not only about their toxicity, but also about eutrophication and ecological degradation. Various aerobic treatment technologies are presented in this chapter to tackle this problem. The treatment technologies are assessed based on five aspects-basic principles, design parameters, treatment efficiency, advantages, and disadvantages. While traditional biofiltration methods are still applied widely, more alternatives such as wetlands, membrane bioreactors, and aquaponics are being considered. Aerobic treatment is mostly effective at removing total ammonium nitrogen or, in other words, nitrification. It is not very efficient at removing nitrate and phosphorus, with the exception of some wetlands, innovative membrane biofilm reactors for denitrification, and aquaponics systems. Therefore, aerobic treatments need to be incorporated into a denitrification process.

Peng, L, Liu, Y, Sun, J & Ni, BJ 2017, 'Handbook of Metal-Microbe Interactions and Bioremediation' in Das, S & Dash, HR (eds), Handbook of Metal-Microbe Interactions and Bioremediation, CRC Press, pp. 689-706.
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Cr(VI) and Cr(III) are the two most ubiquitous forms of chromium. The remediation of chromium contaminant is primarily dependent on transformation from highly toxic and mobile Cr(VI) to insoluble Cr(III) with less toxicity. Biological Cr(VI) removal is not only a promising method but also a very complicated process. This chapter introduces various remediation processes, highlights important Cr(VI)-reducing microorganisms, and reveals underlying mechanisms for bacterial Cr(VI) resistance and reduction. The assessment of key factors limiting and influencing bacterial growth and chromium removal along with reviews on mathematical modeling tended to facilitate further application of microbial Cr(VI) removal in the bench scale, pilot scale, and in situ studies under a wide array of environmental conditions.

Tijing, LD, Woo, YC, Yao, M, Ren, J & Shon, HK 2017, '1.16 Electrospinning for Membrane Fabrication: Strategies and Applications' in Drioli, E, Giorno, E & Fontananova, E (eds), Comprehensive Membrane Science and Engineering, Elsevier, England, pp. 418-444.
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Varkey, DR & Doblin, MA 2017, 'Application of ‘Omics’ Approaches to Microbial Oceanography' in Systems Biology of Marine Ecosystems, Springer International Publishing, pp. 223-233.
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Viruses, bacteria, archaea and single celled eukaryotes, collectively known as microbes, dominate the biomass and metabolism of ocean ecosystems. Marine microbes are highly abundant and critical to human survival, but the vast majority of taxa have not yet been cultured. The use of environmental nucleic acid sequencing as a cultivation-independent approach to microbial oceanography has therefore significantly expanded our understanding of the diversity, evolution, biogeography and important biogeochemical roles of marine microorganisms. Here we provide illustrative examples of how genomic, transcriptomic and proteomic approaches have been applied to marine microbes to advance our understanding of their ecology. A remaining challenge is the need to link phenotypes to their environment, requiring a better understanding of genomic features that influence transcription (e.g. promoters and methylation) as well as post-translational modifications, and how such regulatory processes are impacted by extracellular abiotic and biotic processes. In addition, the expansion of available protein and taxonomic databases will greatly increase our capacity to link microbial function to specific taxa.

Abdolali, A, Ngo, HH, Guo, W, Zhou, JL, Zhang, J, Liang, S, Chang, SW, Nguyen, DD & Liu, Y 2017, 'Application of a breakthrough biosorbent for removing heavy metals from synthetic and real wastewaters in a lab-scale continuous fixed-bed column', Bioresource Technology, vol. 229, pp. 78-87.
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© 2017 Elsevier Ltd A continuous fixed-bed study was carried out utilising a breakthrough biosorbent, specifically multi-metal binding biosorbent (MMBB) for removing cadmium, copper, lead and zinc. The effect of operating conditions, i.e. influent flow rate, metal concentration and bed depth was investigated at pH 5.5 ± 0.1 for a synthetic wastewater sample. Results confirmed that the total amount of metal adsorption declined with increasing influent flow rate and also rose when each metal concentration also increased. The maximum biosorption capacities of 38.25, 63.37, 108.12 and 35.23 mg/g for Cd, Cu, Pb and Zn, respectively, were achieved at 31 cm bed height, 10 mL/min flow rate and 20 mg/L initial concentration. The Thomas model better described the whole dynamic behaviour of the column rather than the Dose Response and Yoon–Nelson models. Finally, desorption studies indicated that metal-loaded biosorbent could be used after three consecutive sorption, desorption and regeneration cycles by applying a semi-simulated real wastewater.

Aditya, L, Mahlia, TMI, Rismanchi, B, Ng, HM, Hasan, MH, Metselaar, HSC, Muraza, O & Aditiya, HB 2017, 'A review on insulation materials for energy conservation in buildings', Renewable and Sustainable Energy Reviews, vol. 73, pp. 1352-1365.
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© 2017 Elsevier Ltd In residential sector, air conditioning system takes the biggest portion of overall energy consumption to fulfil the thermal comfort need. In addressing the issue, thermal insulation is one efficient technology to utilize the energy in providing the desired thermal comfort by its environmentally friendly characteristics. The principle of thermal insulation is by the proper installation of insulation using energy-efficient materials that would reduce the heat loss or heat gain, which leads to reduction of energy cost as the result. This paper is aimed to gather most recent developments on the building thermal insulations and also to discuss about the life-cycle analysis and potential emissions reduction by using proper insulation materials.

Ahmed, MB, Johir, MAH, Zhou, JL, Ngo, HH, Guo, W & Sornalingam, K 2017, 'Photolytic and photocatalytic degradation of organic UV filters in contaminated water', Current Opinion in Green and Sustainable Chemistry, vol. 6, pp. 85-92.
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© 2017 Elsevier B.V. UV filters as emerging contaminants are of great concern and their wide detection in aquatic environments indicates their chemical stability and persistence. This review summarized the photolytic and photocatalytic degradation of UV filters in contaminated water. The findings indicated that limited research has been conducted on the photolysis and photocatalysis of UV filters. Photolysis of UV filters through UV irradiation in natural water was a slow process, which was accelerated by the presence of photosensitisers e.g. triplet state of chromaphoric dissolved organic matter (3CDOM*) and nutrients but reduced by salinity, dissolved organic matter (DOM) and divalent cations. UV Photocatalysis of 4-methylbenzylidene camphor and 2-phenylbenzimidazole-5-sulfonic acid was very effective with 100% removal within 30 min and 90 min using medicated TiO2/H2O2 and TiO2, respectively. The radiation source, type of catalyst and oxygen content were key factors. Future research should focus on improved understanding of photodegradation pathways and by-products of UV filters.

Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Johir, MAH & Belhaj, D 2017, 'Competitive sorption affinity of sulfonamides and chloramphenicol antibiotics toward functionalized biochar for water and wastewater treatment', Bioresource Technology, vol. 238, pp. 306-312.
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© 2017 Elsevier Ltd Competitive sorption of sulfamethazine (SMT), sulfamethoxazole (SMX), sulfathiazole (STZ) and chloramphenicol (CP) toward functionalized biochar (fBC) was highly pH dependent with maximum sorption at pH ∼4.0–4.25. Equilibrium data were well represented by the Langmuir and Freundlich models in the order STZ > SMX > CP > SMT. Kinetics data were slightly better fitted by the pseudo second-order model than pseudo first-order and intra-particle-diffusion models. Maximum sorptive interactions occurred at pH 4.0–4.25 through H-bonds formations for neutral sulfonamides species and through negative charge assisted H-bond (CAHB) formation for CP, in addition to π-π electron-donor-acceptor (EDA) interactions. EDA was the main mechanism for the sorption of positive sulfonamides species and CP at pH < 2.0. Sorption of negative sulfonamides species and CP at pH > 7.0 was regulated by H-bond formation and proton exchange with water by forming CAHB, respectively. The results suggested fBC to be highly efficient in removing antibiotics mixture.

Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Johir, MAH & Sornalingam, K 2017, 'Single and competitive sorption properties and mechanism of functionalized biochar for removing sulfonamide antibiotics from water', Chemical Engineering Journal, vol. 311, pp. 348-358.
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© 2016 Elsevier B.V. Single and competitive sorption of ionisable sulphonamides sulfamethazine, sulfamethoxazole and sulfathiazole on functionalized biochar was highly pH dependent. The equilibrium data were well represented by both Langmuir and Freundlich models for single solutes, and by the Langmuir model for competitive solutes. Sorption capacity and distribution coefficient values decreased as sulfathiazole > sulfamethoxazole > sulfamethazine. The sorption capacity of each antibiotic in competitive mode is about three times lower than in single solute sorption. The kinetics data were best described by the pseudo second-order (PSO) model for single solutes, and by PSO and intra-particle diffusion models for competitive solutes. Adsorption mechanism was governed by pore filling through diffusion process. The findings from pH shift, FTIR spectra and Raman band shift showed that sorption of neutral sulfonamide species occurred mainly due to strong H-bonds followed by π+-π electron-donor-acceptor (EDA), and by Lewis acid-base interaction. Moreover, EDA was the main mechanism for the sorption of positive sulfonamides species. The sorption of negative species was mainly regulated by proton exchange with water forming negative charge assisted H-bond (CAHB), followed by the neutralization of –OH groups by H+released from functionalized biochar surface; in addition π-π electron-acceptor-acceptor (EAA) interaction played an important role.

Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Johir, MAH, Sornalingam, K & Sahedur Rahman, M 2017, 'Chloramphenicol interaction with functionalized biochar in water: sorptive mechanism, molecular imprinting effect and repeatable application', Science of The Total Environment, vol. 609, pp. 885-895.
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© 2017 Elsevier B.V. Biochar and functionalized biochar (fBC-1 and fBC-2) were prepared and applied to remove antibiotic chloramphenicol from deionized water, lake water and synthetic wastewater. Results showed that chloramphenicol removal on biochar was pH dependent and maximum sorption occurred at pH 4.0–4.5. The sorption data of chloramphenicol fitted better with the Langmuir isotherm model than the Freundlich isotherm model with the maximum Langmuir sorption capacity of 233 μM g− 1 using fBC-2. Chloramphenicol sorption on fBC-2 followed the trend: deionized water > lake water > synthetic wastewater. The presence of humic acid decreased the sorption distribution coefficient (Kd) while the presence of low ionic strength and soil in solution increased Kd value significantly. The mechanism of sorption on fBC mainly involved electron-donor-acceptor (EDA) interactions at pH < 2.0; formation of charge assisted hydrogen bond (CAHB) and hydrogen bonds in addition to EDA in the pH 4.0–4.5; and CAHB and EDA interactions at pH > 7.0. Additionally, solvent and thermal regeneration of fBC-2 for repeatable applications showed excellent sorption of chloramphenicol under the same condition, due to the creation of a molecular imprinting effect in fBC-2. Consequently, fBC-2 can be applied with excellent reusability properties to remove chloramphenicol and other similar organic contaminants.

Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Johir, MAH, Sornalingam, K, Belhaj, D & Kallel, M 2017, 'Nano-Fe 0 immobilized onto functionalized biochar gaining excellent stability during sorption and reduction of chloramphenicol via transforming to reusable magnetic composite', Chemical Engineering Journal, vol. 322, pp. 571-581.
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© 2017 Elsevier B.V. The widely used nanosized zero-valent iron (nZVI or nFe0) particles and their composite material lose reductive nature during application, and the stability of transformed composite material for repeatable application is not addressed to date. To shed light on this, nZVI was synthesized from scrap material and immobilized on functionalized biochar (fBC) to prepare nZVI-fBC composite. Comparative study between nZVI and nZVI-fBC composite on the removal of chlorinated antibiotic chloramphenicol from different water types was conducted. The results suggested that nZVI was solely responsible for reduction of chloramphenicol. Whereas nZVI-fBC could be applied once, within a few hours, for the reduction of chloramphenico (29–32.5%) and subsequently sorption (67.5–70.5%) by transforming to a fully magnetic composite (nFe3O4-fBC) gaining stability with synergistic sorption performance. In both cases, two reduction by-products were identified namely 2-chloro-N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 257) and dechlorinated N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 223). The complete removal of 3.1 µM L−1 of chloramphenicol in different water was faster by nZVI-fBC (∼12–15 h) than by stable nFe3O4-fBC composite (∼18 h). Both nZVI-fBC and nFe3O4-fBC composites removed chloramphenicol in the order: deionized water > lake water > synthetic wastewater. nFe3O4-fBC showed excellent reusability after regeneration, with the regenerated nFe3O4-fBC composite (after 6 cycles of application) showing significant performance for methylene blue removal (∼287 mg g−1). Therefore, the transformed nFe3O4-fBC composite is a promising and reusable sorbent for the efficient removal of organic contaminants.

Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Thomaidis, NS & Xu, J 2017, 'Progress in the biological and chemical treatment technologies for emerging contaminant removal from wastewater: A critical review', Journal of Hazardous Materials, vol. 323, pp. 274-298.
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© 2016 Elsevier B.V. This review focuses on the removal of emerging contaminants (ECs) by biological, chemical and hybrid technologies in effluents from wastewater treatment plants (WWTPs). Results showed that endocrine disruption chemicals (EDCs) were better removed by membrane bioreactor (MBR), activated sludge and aeration processes among different biological processes. Surfactants, EDCs and personal care products (PCPs) can be well removed by activated sludge process. Pesticides and pharmaceuticals showed good removal efficiencies by biological activated carbon. Microalgae treatment processes can remove almost all types of ECs to some extent. Other biological processes were found less effective in ECs removal from wastewater. Chemical oxidation processes such as ozonation/H2O2, UV photolysis/H2O2 and photo-Fenton processes can successfully remove up to 100% of pesticides, beta blockers and pharmaceuticals, while EDCs can be better removed by ozonation and UV photocatalysis. Fenton process was found less effective in the removal of any types of ECs. A hybrid system based on ozonation followed by biological activated carbon was found highly efficient in the removal of pesticides, beta blockers and pharmaceuticals. A hybrid ozonation-ultrasound system can remove up to 100% of many pharmaceuticals. Future research directions to enhance the removal of ECs have been elaborated.

Alanezi, AA & Altaee, A 2017, 'Enhanced Performance Dual Stage Pressure Retarded Osmosis', Energy Procedia, vol. 142, pp. 4182-4197.
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© 2017 The Authors. Published by Elsevier Ltd. A dual stage PRO process has been proposed for power generation from a salinity gradient across a semi-permeable membrane. Both closed-loop and open-loop dual stage PRO system were evaluated using 2 M NaCl and Dead Sea as draw solutions, whereas the feed solution was either fresh water or seawater. The impact of feed salinity gradient resource and feed pressure on the net power generation and water flux were evaluated. DSPRO can be combined with desalination plant using seawater brine as the draw solution either in closed-loop or open-loop. This hybridization has multiple applications such as reducing the impact of discharging concentrated brine to sea, energy storage, and increase the recovery rate of the desalination. Power generation by DSPRO will reduce the energy consumption by the desalination processes. Waste heat from power plants can be used for the regeneration of the draw solution in the closed-loop DSPRO. Process modelling has been performed and shown promising results for DSPRO application for power generation.

Alharbi, SK, Kang, J, Nghiem, LD, van de Merwe, JP, Leusch, FDL & Price, WE 2017, 'Photolysis and UV/H 2 O 2 of diclofenac, sulfamethoxazole, carbamazepine, and trimethoprim: Identification of their major degradation products by ESI–LC–MS and assessment of the toxicity of reaction mixtures', Process Safety and Environmental Protection, vol. 112, no. Part B, pp. 222-234.
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© 2017 Institution of Chemical Engineers The photolysis of diclofenac (DCF), sulfamethoxazole (SMX), carbamazepine (CBZ), and trimethoprim (TMP) was investigated using a low-pressure (LP) mercury ultraviolet (UV) lamp (254 nm) and a combination of UV with hydrogen peroxide (H 2 O 2 ). For each experiment, 5 mg/L of each pharmaceutical was prepared in pure water and individually degraded by either UV alone or UV/H 2 O 2 . DCF and SMX were highly susceptible to UV treatment and completely degraded to below their LC–MS detection limit (1 μg/L) after only 8 min of UV irradiation. TMP and CBZ were more resistant to UV treatment, with only 58.2 and 25.2% degradation (after 1 h UV exposure). The combination of H 2 O 2 addition (up to 0.2 g/L) with UV significantly improved the removal rate of TMP and CBZ up to 91.2 and 99.7% of the initial concentration, respectively. A number of novel transformation compounds were identified as UV or UV/H 2 O 2 degradation products using LC–MS. The range and amount of these transformation compounds strongly depended on the applied treatment conditions. The toxicity of each pharmaceutical solution before and after treatment was also evaluated and all parent compounds were non-toxic at the tested concentration (i.e. 5 mg/L). DCF, in particular, but also CBZ and SMX, showed an increase in solution toxicity after treatment with UV only, indicating the presence of photolytic degradation products that are more toxic than the parent compounds. Treatment with UV/H 2 O 2 reduced the toxicity of all solutions to below the detection limit of the assay.

Altaee, A, Millar, GJ, Zaragoza, G & Sharif, A 2017, 'Energy efficiency of RO and FO–RO system for high-salinity seawater treatment', Clean Technologies and Environmental Policy, vol. 19, no. 1, pp. 77-91.
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© 2016, Springer-Verlag Berlin Heidelberg. Forward osmosis (FO) has been proposed as an alternative method for seawater desalination, wherein reverse osmosis (RO) membrane technology is used for regeneration of the draw solution. Previous studies have indicated that a standalone RO unit is more energy efficient than an FO–RO system, and as such it was recommended that an FO–RO system is best employed only for the desalination of high-salinity seawaters. This study examined FO–RO applicability in more detail by examining the impact of seawater salinity, impact of an energy recovery device (ERD), and the effect of membrane fouling. For comparison purposes, the performance of the FO process was improved to minimize the impact of concentration polarization and optimize the concentration of draw solution. Model calculations revealed that FO–RO is more energy efficient than RO when no ERD was employed. However, results showed that there was no significant difference in the power consumption between the FO–RO system and the RO unit at high seawater salinities particularly when a high-efficiency ERD was installed. Moreover, the FO–RO system required more membrane area than a conventional RO unit which may further compromise the FO–RO desalination cost.

Altaee, A, Palenzuela, P, Zaragoza, G & AlAnezi, AA 2017, 'Single and dual stage closed-loop pressure retarded osmosis for power generation: Feasibility and performance', Applied Energy, vol. 191, pp. 328-345.
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© 2017 Elsevier Ltd This work proposes an analysis of conventional (single stage) and dual stage Closed-Loop Pressure Retarded Osmosis (CLPRO) for power generation from a salinity gradient resource. Model calculations were performed taking into account the influence of operating parameters such as the draw solution concentration, membrane area, and draw solution pressure on the performance of the CLPRO process. Modeling results showed that the dual stage CLPRO process outperformed the conventional CLPRO process and power generation increased 18% by adding a second stage of PRO membrane. Multi-Effect Distillation (MED) was selected for the regeneration of the draw solution taking advantage of an available source of waste heat energy. The performance of MED process has been assessed by investigating two key parameters: the specific thermal consumption and the specific heat transfer area. The model calculations showed that the power generation by the single and dual stage CLPRO was higher than the electrical power consumption by the MED plant. In the case of the power generation obtained by the dual stage CLPRO, it was 95% higher than the electrical power consumption by the MED plant, proving the possibility of using low-grade heat for producing electricity from a salinity gradient resource.

Altaee, A, Zaragoza, G, Drioli, E & Zhou, J 2017, 'Evaluation the potential and energy efficiency of dual stage pressure retarded osmosis process', Applied Energy, vol. 199, pp. 359-369.
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© 2017 Power generation by means of Pressure Retarded Osmosis (PRO) has been proposed for harvesting the energy of a salinity gradient. Energy recovery by the PRO process decreases along the membrane module due to depleting of the chemical potential across the membrane and concentration polarization effects. A dual stage PRO (DSPRO) design can be used to rejuvenate the chemical potential difference and reduce the concentration polarization on feed solution. Several design configurations were suggested for the membrane module arrangements in the first and second stage of the PRO process. PRO performance was evaluated for a number of salinity gradients proposed by coupling Dead Sea water or Reverse Osmosis (RO) brine with seawater or wastewater effluent. Maximum specific energy of inlet and outlet feeds was calculated using a developed computer model to identify the amount of recovered and remaining energy. Initially, specific power generation by the PRO process increased by increasing the number of modules of the first stage. Maximum specific energy is calculated along the PRO module to understand the degradation of the maximum specific energy in each module before introducing a second stage PRO process. Adding a second stage PRO process resulted in a sharp increase of the chemical potential difference and the specific energy yield of the process. Between 10% and 13% increase of the specific power generation was achieved by the DSPRO process for the Dead Sea-seawater salinity gradient depending on the dual stage design configuration. For Dead Sea-RO brine, 12–16% increase of the specific power generation was achieved by the dual stage PRO process. For Dead Sea-wastewater and RO brine-wastewater, a neutral and sometimes negative impact occurred when a second stage PRO process was introduced. We concluded that, for a given draw solution concentration, dual stage performs better than the conventional PRO process at high feed salinities, yet requires lower h...

Altaee, A, Zhou, J, Alhathal Alanezi, A & Zaragoza, G 2017, 'Pressure retarded osmosis process for power generation: Feasibility, energy balance and controlling parameters', Applied Energy, vol. 206, pp. 303-311.
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© 2017 The feasibility of pressure-retarded osmosis (PRO) for power generation was evaluated with consideration of the energy inputs and losses in the process. The effects of the concentration polarization, reverse salt diffusion, and external resistance at the membrane porous layer were quantified, for the first time, along the membrane module to determine their contributions to the energy loss in the PRO process. Concentration polarization was responsible for up to 40% of the energy loss during the PRO process. However, increasing the PRO membrane modules from 1 to 4 resulted in a variable increase of the energy output depending on the salinity gradient. The energy requirements for draw and feed solution pretreatment were estimated to be over 38% of the total energy inputs. Results showed that coupling seawater (SW) with river water (RW) was unable to generate sufficient energy to compensate for the energy inputs and losses during the PRO process. With 0.39 kwh/m3 maximum specific energy in the PRO process, the energy yield of reverse osmosis brine (ROB)-wastewater (WW) salinity gradient was slightly greater than the total energy inputs, although using Dead Sea-SW/ROB salinity gradient was more promising. Overall, the primary current limitation is the lack of suitable PRO membranes that can withstand a high hydraulic pressure.

Amin, M, Putra, N, Kosasih, EA, Prawiro, E, Luanto, RA & Mahlia, TMI 2017, 'Thermal properties of beeswax/graphene phase change material as energy storage for building applications', Applied Thermal Engineering, vol. 112, pp. 273-280.
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© 2016 Elsevier Ltd Increased energy consumption in buildings is a worldwide issue. This research is concerned with the implementation of a phase change material for thermal storage. This concept has gained great attention as a solution to reduce energy consumption in buildings. Beeswax, which is a phase change material with a high thermal capacity, is investigated in this research. This paper is intended to measure and analyze the thermal properties of beeswax/graphene as a phase change material. The melting temperature, thermal capacity and latent heat were determined using differential scanning calorimetry (DSC), and the thermal conductivity was investigated using a thermal conductivity measurement apparatus. To discover the change in the physical properties due to the effect of nanoparticles, the viscosity of the material was investigated as well. Based on the result from the DSC, the latent heat of 0.3 wt% beeswax/graphene increased by 22.5%. The thermal conductivity of 0.3 wt% beeswax/graphene was 2.8 W/m K. The existence of graphene nanoplatelets enhanced both the latent heat and thermal conductivity of the beeswax. Therefore, based on this result, beeswax/graphene is concluded to have the potential to reduce energy consumption in buildings.

Ansari, AJ, Hai, FI, Price, WE, Drewes, JE & Nghiem, LD 2017, 'Forward osmosis as a platform for resource recovery from municipal wastewater - A critical assessment of the literature', Journal of Membrane Science, vol. 529, pp. 195-206.
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© 2017 Forward osmosis (FO) is an emerging membrane separation technology that has the potential to serve as a game changer in wastewater treatment. FO-based processes can simultaneously produce high quality effluent and pre-concentrated wastewater for anaerobic treatment to facilitate the recovery of energy and nutrients. Complex wastewaters can be directly pre-treated by FO and fresh water can be produced when coupled with a draw solute recovery process (i.e. reverse osmosis or membrane distillation). By enriching organic carbon and nutrients for subsequent biogas production, FO extends the resource recovery potential of current wastewater treatment processes. Here, we critically review recent applications of FO for simultaneous treatment and resource recovery from municipal wastewater. Research conducted to date highlights the importance of successfully integrating FO with anaerobic treatment. Emphasis is also placed on the development of novel FO-based hybrid systems utilising alternative energy sources for draw solute recovery. There remain several technical challenges to the practical realisation of FO for resource recovery from wastewater including salinity build-up, membrane fouling, and system scale-up. Strategies to overcome these challenges are critically assessed to establish a research roadmap for further development of FO as a platform for resource recovery from wastewater.

Arslan, A, Masjuki, HH, Kalam, MA, Varman, M, Mosarof, MH, Mufti, RA, Quazi, MM, Khuong, LS, Liaqat, M, Jamshaid, M, Alabdulkarem, A & Khurram, M 2017, 'Investigation of laser texture density and diameter on the tribological behavior of hydrogenated DLC coating with line contact configuration', Surface and Coatings Technology, vol. 322, pp. 31-37.
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Aryal, R, Beecham, S, Sarkar, B, Chong, MN, Kinsela, A, Kandasamy, J & Vigneswaran, S 2017, 'Readily Wash-Off Road Dust and Associated Heavy Metals on Motorways', Water, Air, & Soil Pollution, vol. 228, no. 1, pp. 1-12.
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© 2016, Springer International Publishing Switzerland. Road dust contains a wide range of potentially health-hazardous pollutant sources. In this study, road dust samples were collected from nine locations along the Sydney orbital motorway during wet weather events and analysed for their mineralogy and heavy metal contents. The aim of this study was to examine for the specific particle size fractions in road dust samples that can be associated with anthropogenic pollutant sources, mainly on the prevalence of heavy metals. Surface morphological and elemental composition of the road dust particles was analysed using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The heavy metal contents and degree of contamination were also investigated including in the two specific particle size fractions of < 75 and 75–150 μm. It was found that the particle size fraction of < 75 μm made up between 6 and 16% of the entire particle size distributions and contributed to more than 90% of the heavy metal contents. In addition, a moderate to high degree of heavy metal contamination was measured in the collected road dust samples, and this was correlated well with the local traffic volumes. The good correlation between heavy metals and traffic volumes in the finer road dust particle size fraction of < 75 μm indicated that the finer road dust particles were not only important in terms of heavy metal attachment, accumulation and mobilisation during wet weather events but they could also provide evidence of potential anthropogenic pollution sources. These findings will facilitate our scientific understanding on the specific role and importance of particle size fractions on the mobilisation of pollutant sources, particularly heavy metals during wet weather events. It is anticipated that this study will assist in the development of best management practices for pollution prevention and control strategies on the frequency of road sweeping and rete...

Asif, MB, Hai, FI, Singh, L, Price, WE & Nghiem, LD 2017, 'Degradation of Pharmaceuticals and Personal Care Products by White-Rot Fungi—a Critical Review', Current Pollution Reports, vol. 3, no. 2, pp. 88-103.
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White-rot fungi (WRF) mediated treatment can offer an environmentally friendly platform for the removal of pharmaceuticals and personal care products (PPCPs) from wastewater. These PPCPs may have adverse impacts on aquatic organisms and even human and thus their removal during wastewater treatment is of significant interest to the water industry. Whole-cell WRF or their extracellular lignin modifying enzymes (LMEs) have been reported to efficiently degrade PPCPs that are persistent to conventional activated sludge process. WRF mediated treatment of PPCPs depends on a number of factors including physicochemical properties of PPCPs (e.g., hydrophobicity and chemical structure) and wastewater matrix (e.g., pH, temperature, and dissolved constituents), type of WRF species and their specific extracellular enzymes. This review critically analyzes the performance of whole-cell WRF and their LMEs for the removal of PPCPs; particularly, it offers insights into PPCP removal mechanisms (e.g., biosorption vs. biodegradation) and degradation pathways as well as the formation of intermediate byproducts.

Belhaj, D, Athmouni, K, Frikha, D, Kallel, M, El Feki, A, Maalej, S, Zhou, JL & Ayadi, H 2017, 'Biochemical and physiological responses of halophilic nanophytoplankton (Dunaliella salina) from exposure to xeno-estrogen 17α-ethinylestradiol', Environmental Science and Pollution Research, vol. 24, no. 8, pp. 7392-7402.
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© 2017, Springer-Verlag Berlin Heidelberg. The environmental impacts of various pollutants on the entire levels of organisms are under investigation. Among these pollutants, endocrine-disrupting compounds (EDCs) present a serious hazard, even though the environmental significance of these compounds remains basically unknown. To drop some light on this field, we assessed the effects of a 11-day exposure of 17α-ethinylestradiol (EE2) on the growth, metabolic content, antioxidant response, oxidative stress, and genetic damage of Dunaliella salina, isolated from Tunisian biotopes. The results showed that at 10 ng L−1, EE2 could stimulate the growth of D. salina and increase its cellular content of photosynthetic pigments and metabolites; however, it did not significantly increase the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) or the level of malondialdehyde (MDA) and hydrogen peroxide (H2O2). In contrast, exposure to high levels of EE2 concentrations significantly inhibited the growth of D. salina (P < 0.05), decreased the cellular content of photosynthetic pigments, increased the cellular content of all of the metabolites and the SOD activity, and inhibited CAT and GPx activities. Nevertheless, the balance between oxidant and antioxidant enzymes was disrupted because H2O2 content along with MDA content simultaneously increased. Contrary to expected results, DNA damage (strand breaks) decreased after the exposure of algae to EE2. The results of this study suggest that EE2 toxicity could result in environmental impacts with consequences on the whole aquatic community. [Figure not available: see fulltext.]

Belhaj, D, Frikha, D, Athmouni, K, Jerbi, B, Ahmed, MB, Bouallagui, Z, Kallel, M, Maalej, S, Zhou, J & Ayadi, H 2017, 'Box-Behnken design for extraction optimization of crude polysaccharides from Tunisian Phormidium versicolor cyanobacteria (NCC 466): Partial characterization, in vitro antioxidant and antimicrobial activities', International Journal of Biological Macromolecules, vol. 105, pp. 1501-1510.
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© 2017 In this study, response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to optimize the aqueous extraction of crude polysaccharides from Tunisian cyanobacteria Phormidium versicolor (NCC 466). The optimal extraction conditions with an extraction yield of 21.56 ± 0.92% were as follows: extraction temperature at 81.05 °C, extraction time of 3.99 h, and water to raw material ratio of 21.52 mL g−1. Crude Phormidium versicolor polysaccharides (CPv-PS) are found to be a hetero-sulfated-anionic polysaccharides that contained carbohydrate (79.37 ± 1.58%), protein (0.45 ± 0.11%), uronic acids (4.37 ± 0.19%) and sulfate (6.83 ± 0.28%). The carbohydrate fraction was composed of arabinose, xylose, ribose, rhamnose, N-acetyl glucosamine, galactose, glucose, mannose, glucuronic acid and saccharose with corresponding mole percentages of 2.41, 14.58, 2.18, 6.23, 7.04, 28.21, 26.04, 3.02, 0.86 and 5.07, respectively. Evaluation of the antioxidant activity in vitro suggested that CPv-PS strongly scavenged radicals, prevented bleaching of β-carotene and reduced activity. Furthermore, the CPv-PS exhibited effective antimicrobial properties.

Bellgrove, A, van Rooyen, A, Weeks, AR, Clark, JS, Doblin, MA & Miller, AD 2017, 'New resource for population genetics studies on the Australasian intertidal brown alga, Hormosira banksii: isolation and characterization of 15 polymorphic microsatellite loci through next generation DNA sequencing', Journal of Applied Phycology, vol. 29, no. 3, pp. 1721-1727.
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© 2016, Springer Science+Business Media Dordrecht. The Australasian fucoid, Hormosira banksii, commonly known as ‘Neptune’s necklace’ or ‘bubbleweed’ is regarded as an autogenic ecosystem engineer with no functional equivalents. Population declines resulting from climate change and other anthropogenic disturbances pose significant threats to intertidal biodiversity. For effective conservation strategies, patterns of gene flow and population genetic structure across the species distribution need to be clearly understood. We developed a suite of 15 polymorphic microsatellite markers using next generation sequencing of 53–55 individuals from two sites (south-western Victoria and central New South Wales, Australia) and a replicated spatially hierarchical sampling design. We observed low to moderate genetic variation across most loci (mean number of alleles per locus =3.26; mean expected heterozygosity =0.38) with no evidence of individual loci deviating significantly from Hardy-Weinberg equilibrium. Marker independence was confirmed with tests for linkage disequilibrium, and analyses indicated no evidence of null alleles across loci. Independent spatial autocorrelation analyses were performed for each site using multilocus genotypes and different relatedness measures. Both analyses indicated no significant patterns between relatedness and geographic distance, complemented by non-significant Hardy-Weinberg estimates (P  <  0.05), suggesting that individuals from each site represent a randomly mating, outcrossing population. A preliminary investigation of population structure indicates that gene flow among sites is limited (F ST  = 0.49), however more comprehensive sampling is needed to determine the extent of population structure across the species range ( > 10,000 km). The genetic markers described provide a valuable resource for future population genetic assessments that will help guide conservation planning for H. banksii and the associated intertidal communities.

Bishop, D, Situ, R, Brown, R & Surawski, N 2017, 'Numerical Modelling of Biodiesel Blends in a Diesel Engine', Energy Procedia, vol. 110, pp. 402-407.
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© 2017 The Authors. Biodiesel is a biofuel which has similar properties to diesel and can readily be used in a diesel engine with minimal modifications. Promising results have been determined using mixtures of biodiesel and diesel with the reduction of soot and emissions of a diesel engine. Experimental analysis of diesel engines can be expensive and therefore Computation Fluid Dynamics programs are used to analyses the combustion process. The AVL Fire ESED program is currently being employed to investigate the effects of biodiesel on the diesel engines soot, emissions and power generation from a Cummins ISBE220 engine. Investigation is performed on pre and post injection-rate shapes on the combustion process establishing the results correlate accurately with researched data. A pre injection was determined to increase maximum power, reduce combustion generated noise, increase early in cylinder temperature and reduce fuel consumption due to the increase in power. A post injection was verified to reduce soot emissions while increasing NOx emissions marginally. The investigation of the injection-rate shape established the soot-NOx trade-off which was also found in the research. The models developed were agreeable with biodiesel data with percentage error in indicated power ranging from 1.62-8.85%. The models suggested that biodiesel assists in reducing NOx and soot emissions. The soot-NOx trade-off was further investigated determining the theory that then by reducing the combustion temperature in the combustion chamber the NOx emissions can be reduced while increasing soot emissions. By increasing the temperature in the combustion chamber the opposite effect was found to occur.

Brodersen, KE, Hammer, KJ, Schrameyer, V, Floytrup, A, Rasheed, MA, Ralph, PJ, Kühl, M & Pedersen, O 2017, 'Sediment Resuspension and Deposition on Seagrass Leaves Impedes Internal Plant Aeration and Promotes Phytotoxic H2S Intrusion', Frontiers in Plant Science, vol. 8, pp. 1-13.
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© 2017 Brodersen, Hammer, Schrameyer, Floytrup, Rasheed, Ralph, Kühl and Pedersen. Anthropogenic activities leading to sediment re-suspension can have adverse effects on adjacent seagrass meadows, owing to reduced light availability and the settling of suspended particles onto seagrass leaves potentially impeding gas exchange with the surrounding water. We used microsensors to determine O2 fluxes and diffusive boundary layer (DBL) thickness on leaves of the seagrass Zostera muelleri with and without fine sediment particles, and combined these laboratory measurements with in situ microsensor measurements of tissue O2 and H2 S concentrations. Net photosynthesis rates in leaves with fine sediment particles were down to ∼20% of controls without particles, and the compensation photon irradiance increased from a span of 20–53 to 109–145 µmol photons m−2 s−1. An ∼2.5-fold thicker DBL around leaves with fine sediment particles impeded O2 influx into the leaves during darkness. In situ leaf meristematic O2 concentrations of plants exposed to fine sediment particles were lower than in control plants and exhibited long time periods of complete meristematic anoxia during night-time. Insufficient internal aeration resulted in H2 S intrusion into the leaf meristematic tissues when exposed to sediment resuspension even at relatively high night-time water-column O2 concentrations. Fine sediment particles that settle on seagrass leaves thus negatively affect internal tissue aeration and thereby the plants’ resilience against H2 S intrusion.

Brodersen, KE, Koren, K, Moßhammer, M, Ralph, PJ, Kühl, M & Santner, J 2017, 'Seagrass-Mediated Phosphorus and Iron Solubilization in Tropical Sediments', Environmental Science & Technology, vol. 51, no. 24, pp. 14155-14163.
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© 2017 American Chemical Society. Tropical seagrasses are nutrient-limited owing to the strong phosphorus fixation capacity of carbonate-rich sediments, yet they form densely vegetated, multispecies meadows in oligotrophic tropical waters. Using a novel combination of high-resolution, two-dimensional chemical imaging of O2, pH, iron, sulfide, calcium, and phosphorus, we found that tropical seagrasses are able to mobilize the essential nutrients iron and phosphorus in their rhizosphere via multiple biogeochemical pathways. We show that tropical seagrasses mobilize phosphorus and iron within their rhizosphere via plant-induced local acidification, leading to dissolution of carbonates and release of phosphate, and via local stimulation of microbial sulfide production, causing reduction of insoluble Fe(III) oxyhydroxides to dissolved Fe(II) with concomitant phosphate release into the rhizosphere porewater. These nutrient mobilization mechanisms have a direct link to seagrass-derived radial O2 loss and secretion of dissolved organic carbon from the below-ground tissue into the rhizosphere. Our demonstration of seagrass-derived rhizospheric phosphorus and iron mobilization explains why seagrasses are widely distributed in oligotrophic tropical waters.

Cai, Q, Turner, BD, Sheng, D & Sloan, S 2017, 'Impact of Barium and Cadmium on Defluoridation by Calcite: Batch Reactor and Column Tests', Environmental Engineering Science, vol. 34, no. 11, pp. 792-804.
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Cao, Z, Liu, X, Xu, J, Zhang, J, Yang, Y, Zhou, J, Xu, X & Lowry, GV 2017, 'Removal of Antibiotic Florfenicol by Sulfide-Modified Nanoscale Zero-Valent Iron', Environmental Science & Technology, vol. 51, no. 19, pp. 11269-11277.
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Florfenicol (FF, C12H14Cl2FNO4S), an emerging halogenated organic contaminant of concern was effectively degraded in water by sulfidized nanoscale zerovalent iron (S-nZVI). Sulfidized nZVI (62.5 m2 g-1) that was prepared using a one-step method resulted in small Fe0/Fe-sulfide particles that were more stable against aggregation than unsulfidized nZVI (10.2 m2 g-1). No obvious removal of FF was observed by unsulfidized nZVI. S-nZVI degraded FF, having a surface area normalized reaction rate constant of 3.1 × 10-4 L m-2 min-1. The effects of the S/Fe molar ratio, initial FF concentration, initial pH, temperature, and water composition on the removal of FF by S-nZVI, and on the formation of reaction products, were systematically investigated. Both dechlorination and defluorination were observed, resulting in four degradation products (C12H15ClFNO4S, C12H16FNO4S, C12H17NO4S, and C12H17NO5S). High removal efficiencies of FF by S-nZVI were achieved in groundwater, river water, seawater, and wastewater. The reactivity of S-nZVI was relatively unaffected by the presence of both dissolved ions and organic matter in the waters tested.

Chekli, L, Corjon, E, Tabatabai, SAA, Naidu, G, Tamburic, B, Park, SH & Shon, HK 2017, 'Performance of titanium salts compared to conventional FeCl3 for the removal of algal organic matter (AOM) in synthetic seawater: Coagulation performance, organic fraction removal and floc characteristics', Journal of Environmental Management, vol. 201, pp. 28-36.
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© 2017 Elsevier Ltd During algal bloom periods, operation of seawater reverse osmosis (SWRO) pretreatment processes (e.g. ultrafiltration (UF)) has been hindered due to the high concentration of algal cells and algal organic matter (AOM). The present study evaluated for the first time the performance of titanium salts (i.e. titanium tetrachloride (TiCl4) and polytitanium tetrachloride (PTC)) for the removal of AOM in seawater and results were compared with the conventional FeCl3 coagulant. Previous studies already demonstrated that titanium salts not only provide a cost-effective alternative to conventional coagulants by producing a valuable by-product but also minimise the environmental impact of sludge production. Results from this study showed that both TiCl4 and PTC achieved better performance than FeCl3 in terms of turbidity, UV254 and dissolved organic carbon (DOC) removal at similar coagulant dose. Liquid chromatography – organic carbon detection (LC-OCD) was used to determine the removal of AOM compounds based on their molecular weight (MW). This investigation revealed that both humic substances and low MW organics were preferentially removed (i.e. up to 93% removal) while all three coagulants showed poorer performance for the removal of high MW biopolymers (i.e. less than 50% removal). The detailed characterization of flocs indicated that both titanium coagulants can grow faster, reach larger size and present a more compact structure, which is highly advantageous for the design of smaller and more compact mixing and sedimentation tanks. Both titanium coagulants also presented a higher ability to withstand shear force, which was related to the higher amount of DOC adsorbed with the aggregated flocs. Finally, TiCl4 had a better recovery after breakage suggesting that charge neutralization may be the dominant mechanism for this coagulant, while the lower recovery of both PTC and FeCl3 indicated that sweep flocculation is also a contributing mechan...

Chekli, L, Eripret, C, Park, SH, Tabatabai, SAA, Vronska, O, Tamburic, B, Kim, JH & Shon, HK 2017, 'Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl 4 ) and ferric chloride (FeCl 3 ) in algal turbid water', Separation and Purification Technology, vol. 175, pp. 99-106.
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© 2016 Elsevier B.V. Seasonal green algae blooms in freshwaters have raised attention on the need to develop novel effective treatment processes for the removal of algae in water. In the present study, the performance of newly developed polytitanium tetrachloride (PTC) coagulant for the removal of freshwater microalga Chlorella vulgaris has been investigated and compared with titanium tetrachloride (TiCl4) coagulant and the conventional ferric chloride (FeCl3) coagulant. The main benefit of using titanium-based coagulants is that the sludge produced after flocculation may be recycled into a valuable product: titanium dioxide photocatalyst. Both titanium-based coagulants achieved good flocculation over a broader pH range and coagulant dose compared to conventional FeCl3 coagulant. All three coagulants achieved comparable performance in terms of turbidity removal (i.e. turbidity removal efficiency >97%); although TiCl4 performed slightly better at the lower tested dose (i.e. <9 mg/L). Zeta potential measurements indicated that charge neutralisation may not be the sole mechanism involved in the coagulation of algae for all three coagulants. Analysis of the dynamic floc size variation during floc breakage showed no regrowth after floc breakage for the three coagulants. The flocs formed by both Ti-based coagulants were larger than those formed by FeCl3 and also grew at a faster rate. This study indicates that Ti-based coagulants are effective and promising coagulants for algae removal in water.

Chekli, L, Kim, JE, El Saliby, I, Kim, Y, Phuntsho, S, Li, S, Ghaffour, N, Leiknes, T & Kyong Shon, H 2017, 'Fertilizer drawn forward osmosis process for sustainable water reuse to grow hydroponic lettuce using commercial nutrient solution', Separation and Purification Technology, vol. 181, pp. 18-28.
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© 2017 Elsevier B.V. This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil. Results from the bench-scale experiments showed that the commercial hydroponic nutrient solution (i.e. solution containing water and essential nutrients) exhibited similar performance (i.e., water flux and reverse salt flux) to other inorganic draw solutions when treating synthetic wastewater. The use of hydroponic solution is highly advantageous since it provides all the required macro- (i.e., N, P and K) and micronutrients (i.e., Ca, Mg, S, Mn, B, Zn and Mo) in a single balanced solution and can therefore be used directly after dilution without the need to add any elements. After long-term operation (i.e. up to 75% water recovery), different physical cleaning methods were tested and results showed that hydraulic flushing can effectively restore up to 75% of the initial water flux while osmotic backwashing was able to restore the initial water flux by more than 95%; illustrating the low-fouling potential of the FDFO process. Pilot-scale studies demonstrated that the FDFO process is able to produce the required nutrient concentration and final water quality (i.e., pH and conductivity) suitable for hydroponic applications. Coupling FDFO with pressure assisted osmosis (PAO) in the later stages could help in saving operational costs (i.e., energy and membrane replacement costs). Finally, the test application of nutrient solution produced by the pilot FDFO process to hydroponic lettuce showed similar growth pattern as the control without any signs of nutrient deficiency.

Chekli, L, Kim, Y, Phuntsho, S, Li, S, Ghaffour, N, Leiknes, T & Shon, HK 2017, 'Evaluation of fertilizer-drawn forward osmosis for sustainable agriculture and water reuse in arid regions', Journal of Environmental Management, vol. 187, pp. 137-145.
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© 2016 Elsevier Ltd The present study focused on the performance of the FDFO process to achieve simultaneous water reuse from wastewater and production of nutrient solution for hydroponic application. Bio-methane potential (BMP) measurements were firstly carried out to determine the effect of osmotic concentration of wastewater achieved in the FDFO process on the anaerobic activity. Results showed that 95% water recovery from the FDFO process is the optimum value for further AnMBR treatment. Nine different fertilizers were then tested based on their FO performance (i.e. water flux, water recovery and reverse salt flux) and final nutrient concentration. From this initial screening, ammonium phosphate monobasic (MAP), ammonium sulfate (SOA) and mono-potassium phosphate were selected for long term experiments to investigate the maximum water recovery achievable. After the experiments, hydraulic membrane cleaning was performed to assess the water flux recovery. SOA showed the highest water recovery rate, up to 76% while KH2PO4 showed the highest water flux recovery, up to 75% and finally MAP showed the lowest final nutrient concentration. However, substantial dilution was still necessary to comply with the standards for fertigation even if the recovery rate was increased.

Chen, C, Guo, W, Ngo, HH, Chang, SW, Duc Nguyen, D, Dan Nguyen, P, Bui, XT & Wu, Y 2017, 'Impact of reactor configurations on the performance of a granular anaerobic membrane bioreactor for municipal wastewater treatment', International Biodeterioration & Biodegradation, vol. 121, pp. 131-138.
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© 2017 Elsevier Ltd This study compared overall performance of an external granular anaerobic membrane bioreactor and a submerged granular anaerobic membrane bioreactor (EG-AnMBR and SG-AnMBR, respectively), to determine which type of G-AnMBRs is more preferred for municipal wastewater treatment. Both systems presented similar COD removal efficiencies (over 91%) and methane yield of 160 mL CH4 (STP) (g COD removed)−1 although volatile fatty acids (VFA) accumulation was found in the SG-AnMBR. Membrane direct incorporation into the SG-AnMBR significantly affected the concentration and properties of microbial products (e.g. soluble microbial products (SMP) and extracellular polymeric substances (EPS)) in the cake layer, mixed liquor and granular sludge, as well as granular sludge size and settleability. The EG-AnMBR demonstrated less SMP and EPS in the mixed liquor and cake layer, which might reduce the cake layer resistance and lower the fouling rate. Liquid chromatography-organic carbon detection (LC-OCD) analysis of foulant revealed that biopolymers along with low molecular weight neutrals and acids and building blocks were responsible for higher fouling propensity in the SG-AnMBR. It is evident that compared to the SG-AnMBR, the EG-AnMBR serves as a better G-AnMBR configuration for municipal wastewater treatment due to less fouling propensity and superior granule quality.

Chen, C, Guo, WS, Ngo, HH, Liu, Y, Du, B, Wei, Q, Wei, D, Nguyen, DD & Chang, SW 2017, 'Evaluation of a sponge assisted-granular anaerobic membrane bioreactor (SG-AnMBR) for municipal wastewater treatment', Renewable Energy, vol. 111, pp. 620-627.
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© 2017 Elsevier Ltd This study compared a conventional granular anaerobic membrane bioreactor (CG-AnMBR) with a sponge assisted-granular anaerobic membrane bioreactor (SG-AnMBR) in terms of treatment performance, granular sludge properties, membrane fouling behaviour and biogas production. The SG-AnMBR showed better organics and nutrient removal, and enhanced methane yield at 156.3 ± 5.8 mL CH4(STP)/g CODremoved. Granular sludge from the SG-AnMBR had superior quality with better settleability, larger particle size, higher EPS content and more granule abundance. The SG-AnMBR also exhibited slower fouling development with 50.7% lower total filtration resistance than those of the CG-AnMBR. Sponge addition effectively affected the concentration and properties of microbial products (e.g. soluble microbial products (SMP) and extracellular polymeric substances (EPS)) in granular sludge, cake layer as well as settling zone mixed liquor, thus alleviating the fouling propensity. The liquid chromatography-organic carbon detection (LC-OCD) analysis suggested that sponge addition reduced the concentrations of biopolymers, low molecular weight neutrals and acids, and building blocks of the foulants. Compared with the SG-AnMBR, GC-MS analysis confirmed the accumulation of volatile fatty acids, particularly acetic acid in the CG-AnMBR. It is evident that the SG-AnMBR could be a promising solution for improving overall G-AnMBR performance and substantially mitigating membrane fouling.

Chen, G, Liu, R, Shon, HK, Wang, Y, Song, J, Li, X-M & He, T 2017, 'Open porous hydrophilic supported thin-film composite forward osmosis membrane via co-casting for treatment of high-salinity wastewater', Desalination, vol. 405, pp. 76-84.
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© 2016 High-performance thin film composite (TFC) forward osmosis (FO) membranes with a low degree of internal concentration polarization (ICP) are critical for concentrating high-salinity wastewaters. This report focuses on the preparation of TFC FO membranes via a sacrificial approach. In order to improve the FO flux, hydrophilicity and morphology of the support membrane were mainly investigated. The hydrophilicity of the polysulfone (PSF) substrate was tuned by blending with sulfonated poly (ether ether ketone) (SPEEK), and the resulting SPEEK blended PSF membrane was denoted as SPSF substrate. The pore structure of the SPSF membrane was tailored by the application of a co-casting technique, which yielded a TFC membrane with a structure parameter (S) of 191 μm. In contrast, the TFC membranes based on the PSF and SPSF substrates through single layer casting showed S values of 527 μm and 361 μm, respectively. These results indicate that the combined hydrophilicity and open pore structure are responsible for the lowered S value. Further application of the hydrophilic substrate based TFC membranes in the treatment of high salinity wastewaters (10 wt%) demonstrated the higher initial water flux (28.3 L/m2·h) with a water recovery rate of 53.2% in comparison to the TFC membrane based on the pristine PSF through the single layer casting. This new method paves a way to generate high-performing FO membranes.

Chen, H, Yue, Y, Jin, W, Zhou, X, Wang, Q, Gao, S-H, Xie, G-J, Du, S, Tu, R, Han, S & Guo, K 2017, 'Enrichment and characteristics of ammonia-oxidizing archaea in wastewater treatment process', Chemical Engineering Journal, vol. 323, pp. 465-472.
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High purity ammonia-oxidizing archaea (AOA) culture containing a single AOA strain was enriched from the filtering materials of biological aerated filter. The concentration of AOA reached 3.27 × 107 copies/mL, while its proportion was 91.40%. The AOA amoA gene sequence belonged to Nitrososphaera cluster. Ammonia concentration significantly influenced the growth of AOA in culture, while total organic carbon (TOC) concentration had no obvious effect. The optimum ammonia concentration, temperature, pH and DO concentration for growth of AOA were 1 mM, 30 °C, 7.5 and 2.65 mg/L, respectively. Under the optimum growth conditions, the AOA abundance and ammonia oxidation rate were 3.53 × 107 copies/mL and 2.54 × 10−10 mg/(copies·d).

Chen, X, Liu, Y, Peng, L & Ni, B-J 2017, 'Perchlorate, nitrate, and sulfate reduction in hydrogen-based membrane biofilm reactor: Model-based evaluation', Chemical Engineering Journal, vol. 316, pp. 82-90.
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© 2017 Elsevier B.V. A biofilm model was developed to evaluate the key mechanisms including microbially-mediated ClO4−, NO3−, and SO42−reduction in the H2-based membrane biofilm reactor (MBfR). Sensitivity analysis indicated that the maximum growth rate of H2-based denitrification (μ1) and maximum growth rate of H2-based SO42−reduction (μ3) could be reliably estimated by fitting the model predictions to the experimental measurements. The model was first calibrated using the experimental data of a single-stage H2-based MBfR fed with different combinations of ClO4−, NO3−, and/or SO42−together with a constant dissolved oxygen (DO) concentration at three operating stages. μ1and μ3were determined at 0.133 h−1and 0.0062 h−1, respectively, with a good level of identifiability. The model and the parameter values were further validated based on the experimental data of a two-stage H2-based MBfR system fed with ClO4−, NO3−, SO42−, and DO simultaneously but at different feeding rates during two running phases. The validated model was then applied to evaluate the quantitative and systematic effects of key operating conditions on the reduction of ClO4−, NO3−, and SO42−as well as the steady-state microbial structure in the biofilm of a single-stage H2-based MBfR. The results showed that i) a higher influent ClO4−concentration led to a higher ClO4−removal efficiency, compensated by a slightly decreasing SO42−removal; ii) the H2loading should be properly managed at certain critical level to maximize the ClO4−and NO3−removal while limiting the growth of sulfate reducing bacteria which would occur in the case of excessive H2supply; and iii) a moderate hydraulic retention time and a relatively thin biofilm were required to maintain high-level removal of ClO4−and NO3−but restrict the SO42−reduction.

Cheng, L, Chen, Y, Zheng, YY, Zhan, Y, Zhao, H & Zhou, JL 2017, 'Bioaccumulation of sulfadiazine and subsequent enzymatic activities in Chinese mitten crab (Eriocheir sinensis)', Marine Pollution Bulletin, vol. 121, no. 1-2, pp. 176-182.
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The bioaccumulation of sulfadiazine and subsequent enzymatic activities in Chinese mitten crab (Eriocheir sinensis) were studied in microcosms, by exposing to 50, 100, 500 and 1000ng/L of sulfadiazine for 44days. An effective method for extracting sulfadiazine in crab tissues was established by modifying the cleanup method after ultrasound extraction, with improved recoveries of 61.8%, 93.7% and 100.5% in gill, muscle and liver samples. The results showed that sulfadiazine residues were all <3ng/g dry weight in different tissues, and that sulfadiazine bioaccumulation in crab was not dose-dependent. A significantly negative correlation was observed between acetylcholinesterase activity and the residue concentration of sulfadiazine during exposure to 50ng/L and 1000ng/L, and between alkaline phosphatase and sulfadiazine residues in the 100ng/L exposure group in the gill, suggesting that the two enzymes played an important role in the metabolism of sulfadiazine in crab.

Choi, Y, Naidu, G, Jeong, S, Vigneswaran, S, Lee, S, Wang, R & Fane, AG 2017, 'Experimental comparison of submerged membrane distillation configurations for concentrated brine treatment', Desalination, vol. 420, pp. 54-62.
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© 2017 Elsevier B.V. Membrane distillation (MD) is an attractive technology for seawater reverse osmosis (SWRO) brine treatment. Submerged MD (S-MD) offers an additional advantage of a compact system compared to cross-flow MD. This study evaluated the performances of three different S-MD configurations; submerged direct contact membrane distillation (S-DCMD), submerged vacuum direct contact membrane distillation (S-VDCMD) and submerged vacuum membrane distillation (S-VMD) for SWRO brine treatment. A 13–77% higher water flux was obtained by S-MDs with vacuum incorporation (S-VMD and S-VDCMD) compared to S-DCMD, attributed to higher driving force. Evaluation on the influence of feed concentration and permeate temperature revealed that S-MD with high vacuum was significantly affected by feed concentration. Meanwhile S-DCMD was more severely affected by feed temperature losses, based on the tendency of membrane pore crystallization formation. The crystallization tendency on the membrane surface was influenced by the presence of vacuum pressure. A repeated cycle of S-DCMD with membrane air-backwashing was effective for flux recovery and to reduce membrane crystallization, enabling to concentrate SWRO brine by 2.8 times of volume concentration factor.

Chul Woo, Y, Chen, Y, Tijing, LD, Phuntsho, S, He, T, Choi, J-S, Kim, S-H & Kyong Shon, H 2017, 'CF4 plasma-modified omniphobic electrospun nanofiber membrane for produced water brine treatment by membrane distillation', Journal of Membrane Science, vol. 529, pp. 234-242.
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© 2017 Elsevier B.V. This study describes the development and performance of an omniphobic poly(vinylidene fluoride) (PVDF) membrane by electrospinning and CF4plasma surface modification for air gap membrane distillation (AGMD). The effect of different duration of plasma treatment on the nanofiber membrane characteristics was investigated. The AGMD performance of the membranes was evaluated using real reverse osmosis (RO) brine produced from coal seam gas (CSG) water that was added with low surface tension liquid (surfactant) as feed solution. Results indicated the formation of new CF2-CF2and CF3bonds after plasma treatment, which lowered the surface energy of the membrane, providing omniphobic property, as indicated by its wetting resistance to different low surface tension liquids such as methanol, mineral oil and ethylene glycol. Though no appreciative changes in morphology of the membrane were observed after plasma treatment, optimal treatment condition of 15 min (i.e., P/CF-15 membrane) exhibited lotus effect membrane surface with increased liquid entry pressure of 187 kPa compared to 142 kPa for neat membrane. AGMD performance showed stable normalized flux (initial flux of 15.3 L/m2h) and rejection ratio (100%) for P/CF-15 even with the addition of up to 0.7 mM sodium dodecyl sulfate surfactant to the RO brine from CSG produced water feed, while commercial PVDF membrane suffered membrane wetting after 0.3 mM of surfactant addition. Based on the results, the present omniphobic membrane has good potential for producing clean water from challenging waters containing high salinity and organic contaminants.

Chung, W-J, Torrejos, REC, Park, MJ, Vivas, EL, Limjuco, LA, Lawagon, CP, Parohinog, KJ, Lee, S-P, Shon, HK, Kim, H & Nisola, GM 2017, 'Continuous lithium mining from aqueous resources by an adsorbent filter with a 3D polymeric nanofiber network infused with ion sieves', Chemical Engineering Journal, vol. 309, pp. 49-62.
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© 2016 Elsevier B.V. Electrospun composite nanofiber (NF) was fabricated and employed as an adsorbent membrane filter in a continuous Li + mining process from seawater. The filter was composed of a hydrophilic polyacrylonitrile (PAN) matrix infused with lithium ion sieves (LIS) H 1.6 Mn 1.6 O 4 . Characterization of the LIS/PAN NF confirmed its favorable structural and surface properties for effective Li + adsorption. The LIS/PAN NF was mechanically suitable as a microfiltration membrane with high water flux and low pressure requirement. Breakthrough experiments at varied feed concentrations (C f ), seawater flowrates (F), and NF thicknesses (Z) revealed the dynamic adsorption behavior of the filter. The seawater residence time was most critical and must be kept ⩾0.12 min at any given C f and Z to maximize the Li + capacity of the filter. This can be conveniently achieved by adjusting the F of the process. Analogous to a packed bed system, the predictive power of nine breakthrough models were determined through non-linear regression analyses. Results reveal that bed-depth-space-time, Bohart-Adams (BA) and Thomas models adequately predicted the performance of the filter albeit BA exhibited the best agreement. Meanwhile, Wolborska failed to converge with any of the experimental results while Yoon-Nelson, Wang, Clark, dose-response, and modified dose-response were too simple to provide any meaningful information. Cycled Li + adsorption-desorption runs successfully collected and concentrated Li + in a mild acid stripping solution. After ten cycles, Li + was separated 155–1552 times more efficiently than Na + , K + , Mg 2+ and Ca 2+ . Overall results demonstrate the potential of LIS/PAN NF as an adsorbent membrane filter for continuous Li + mining from aqueous resources.

Commault, AS, Laczka, O, Siboni, N, Tamburic, B, Crosswell, JR, Seymour, JR & Ralph, PJ 2017, 'Electricity and biomass production in a bacteria- Chlorella based microbial fuel cell treating wastewater', Journal of Power Sources, vol. 356, pp. 299-309.
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© 2017 Elsevier B.V. The chlorophyte microalga Chlorella vulgaris has been exploited within bioindustrial settings to treat wastewater and produce oxygen at the cathode of microbial fuel cells (MFCs), thereby accumulating algal biomass and producing electricity. We aimed to couple these capacities by growing C. vulgaris at the cathode of MFCs in wastewater previously treated by anodic bacteria. The bioelectrochemical performance of the MFCs was investigated with different catholytes including phosphate buffer and anode effluent, either in the presence or absence of C. vulgaris. The power output fluctuated diurnally in the presence of the alga. The maximum power when C. vulgaris was present reached 34.2 ± 10.0 mW m −2 , double that observed without the alga (15.6 ± 9.7 mW m −2 ), with a relaxation of 0.19 gL −1  d −1 chemical oxygen demand and 5 mg L −1  d −1 ammonium also removed. The microbial community associated with the algal biofilm included nitrogen-fixing (Rhizobiaceae), denitrifying (Pseudomonas stutzeri and Thauera sp., from Pseudomonadales and Rhodocyclales orders, respectively), and nitrate-reducing bacteria (Rheinheimera sp. from the Alteromonadales), all of which likely contributed to nitrogen cycling processes at the cathode. This paper highlights the importance of coupling microbial community screening to electrochemical and chemical analyses to better understand the processes involved in photo-cathode MFCs.

Damanik, N, Ong, HC, Chong, WT & Silitonga, AS 2017, 'Biodiesel production from Calophyllum inophyllum−palm mixed oil', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 39, no. 12, pp. 1283-1289.
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The objective of this study is to investigate the biodiesel production from Calophyllum inophyllum −palm mixed oil. The C. inophyllum–palm biodiesel (C. inophyllum palm oil methyl ester, CPME) is first produced by mixing the crude oils at an equal ratio of 50:50 vol%, followed by degumming, acid-catalyzed esterification, purification, and, last, alkaline-catalyzed transesterification. With this systematic procedure, the acid value of the CPME is 0.4 mg KOH/g, resulting in a significant enhancement of oxidation stability (114.21 h). The results indicate that the fatty acid methyl ester composition of the CPME may be the reason for its larger higher heating value (39.4 MJ/kg) and lower kinematic viscosity (4.15 mm2/s). In short, CPME satisfied the ASTM D6751 and EN 14214 standards as a promising alternative fuel in the future.

Dharma, S, Hassan, MH, Ong, HC, Sebayang, AH, Silitonga, AS & Kusumo, F 2017, 'Optimization of biodiesel production from mixed jatropha curcas-ceiba pentandra using artificial neural network- genetic algorithm: Evaluation of reaction kinetic models', Chemical Engineering Transactions, vol. 56, pp. 547-552.
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Biodiesel production from non-edible vegetable oil is one effective way to anticipate the problems associated with fuel crisis and environmental issues. In this study, artificial neural network and genetic algorithm based Box Behnken experimental design used to optimize the parameters of the biodiesel production for mixed of Jatropha curcas?Ceiba pentandra oil such as methanol to oil ratio, agitation speed and catalyst concentration. Based on the results, the optimum operating parameters for the transesterification of the oil mixture J50C50 are as follows: methanol-To-oil ratio: 40 %v/v, agitation speed: 1,794 rpm and the catalyst concentration: 0.68 % wt. This process is carried out at constant temperature and time of 60 °C and 2 h. The theoretical yield predicted under this the highest yield for the J50C50 biodiesel with a value of 93.70 %. The model developed was validated by applying the optimum values to three independent experimental replicates with a 93.56 %. Comparison between the predicted values to the actual value with a small error percentage indicates that the regression model was reliable in predicting the conversion at any given conditions within the ranges studied. Moreover, the activation energy of 24.421 kJmol-1 and frequency factor of 1.88 x 102 min-1 was required for the transesterification process. The fuel properties of the biodiesel were measured according to ASTM D 6751 and EN14214 standards and found to be within the specifications.

Dharma, S, Hassan, MH, Ong, HC, Sebayang, AH, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Experimental study and prediction of the performance and exhaust emissions of mixed Jatropha curcas-Ceiba pentandra biodiesel blends in diesel engine using artificial neural networks', Journal of Cleaner Production, vol. 164, pp. 618-633.
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Duan, H, Ye, L, Erler, D, Ni, B-J & Yuan, Z 2017, 'Quantifying nitrous oxide production pathways in wastewater treatment systems using isotope technology – A critical review', Water Research, vol. 122, pp. 96-113.
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© 2017 Elsevier Ltd Nitrous oxide (N2O) is an important greenhouse gas and an ozone-depleting substance which can be emitted from wastewater treatment systems (WWTS) causing significant environmental impacts. Understanding the N2O production pathways and their contribution to total emissions is the key to effective mitigation. Isotope technology is a promising method that has been applied to WWTS for quantifying the N2O production pathways. Within the scope of WWTS, this article reviews the current status of different isotope approaches, including both natural abundance and labelled isotope approaches, to N2O production pathways quantification. It identifies the limitations and potential problems with these approaches, as well as improvement opportunities. We conclude that, while the capabilities of isotope technology have been largely recognized, the quantification of N2O production pathways with isotope technology in WWTS require further improvement, particularly in relation to its accuracy and reliability.

Fang, F, Qiao, L-L, Ni, B-J, Cao, J-S & Yu, H-Q 2017, 'Quantitative evaluation on the characteristics of activated sludge granules and flocs using a fuzzy entropy-based approach', Scientific Reports, vol. 7, no. 1, pp. 1-9.
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AbstractActivated sludge granules and flocs have their inherent advantages and disadvantages for wastewater treatment due to their different characteristics. So far quantitative information on their evaluation is still lacking. This work provides a quantitative and comparative evaluation on the characteristics and pollutant removal capacity of granules and flocs by using a new methodology through integrating fuzzy analytic hierarchy process, accelerating genetic algorithm and entropy weight method. Evaluation results show a higher overall score of granules, indicating that granules had more favorable characteristics than flocs. Although large sized granules might suffer from more mass transfer limitation and is prone to operating instability, they also enable a higher level of biomass retention, greater settling velocity and lower sludge volume index compared to flocs. Thus, optimized control of granule size is essential for achieving good pollutant removal performance and simultaneously sustaining long-term stable operation of granule-based reactors. This new integrated approach is effective to quantify and differentiate the characteristics of activated sludge granules and flocs. The evaluation results also provide useful information for the application of activated sludge granules in full-scale wastewater treatment plants.

Faria, AF, Liu, C, Xie, M, Perreault, F, Nghiem, LD, Ma, J & Elimelech, M 2017, 'Thin-film composite forward osmosis membranes functionalized with graphene oxide–silver nanocomposites for biofouling control', Journal of Membrane Science, vol. 525, pp. 146-156.
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© 2016 Elsevier B.V. Innovative approaches to prevent bacterial attachment and biofilm growth on membranes are critically needed to avoid decreasing membrane performance due to biofouling. In this study, we propose the fabrication of anti-biofouling thin-film composite membranes functionalized with graphene oxide–silver nanocomposites. In our membrane modification strategy, carboxyl groups on the graphene oxide–silver nanosheets are covalently bonded to carboxyl groups on the surface of thin-film composite membranes via a crosslinking reaction. Further characterization, such as scanning electron microscopy and Raman spectroscopy, revealed the immobilization of graphene oxide–silver nanocomposites on the membrane surface. Graphene oxide–silver modified membranes exhibited an 80% inactivation rate against attached Pseudomonas aeruginosa cells. In addition to a static antimicrobial assay, our study also provided insights on the anti-biofouling property of forward osmosis membranes during dynamic operation in a cross-flow test cell. Functionalization with graphene oxide–silver nanocomposites resulted in a promising anti-biofouling property without sacrificing the membrane intrinsic transport properties. Our results demonstrated that the use of graphene oxide–silver nanocomposites is a feasible and attractive approach for the development of anti-biofouling thin-film composite membranes.

Fu, Q, Ruan, Q, McKenzie, TG, Reyhani, A, Tang, J & Qiao, GG 2017, 'Development of a Robust PET-RAFT Polymerization Using Graphitic Carbon Nitride (g-C₃N₄)', Macromolecules, vol. 50, no. 19, pp. 7509-7516.
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The metal-free semiconductor, graphitic carbon nitride (g-C3N4), was introduced into RAFT polymerization for the first time. The production of linear polyacrylate and polyacrylamide has been achieved via PET-RAFT polymerization using g-C3N4 as a photoactive organocatalyst without prior deoxygenation. The resulting polymers display controlled molecular weights, narrow polymer dispersities, and high end-group fidelity as exemplified by 1H NMR analysis, MALDI-TOF-MS measurement, and chain extension experiment. Temporal control is illustrated by intermittent light and dark cycles, with polymer growth arrested in the absence of irradiation. The effects of changing RAFT agents (i.e., trithiocarbonates), solvents, catalyst concentrations, and degrees of polymerization in this system have been investigated. The successful polymerization of nonpurified monomer (i.e., still containing radical inhibitors) demonstrates the robust nature of the presented PET-RAFT system.

Fu, Q, Xie, K, McKenzie, TG & Qiao, GG 2017, 'Trithiocarbonates as intrinsic photoredox catalysts and RAFT agents for oxygen tolerant controlled radical polymerization', Polymer Chemistry, vol. 8, no. 9, pp. 1519-1526.
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In this study, we reported on the discovery that trithiocarbonates (RAFT agents) can act as intrinsic photocatalyst to significantly reduce the oxygen level in a controlled radical polymerization under visible light irridation.

Fujioka, T, Kodamatani, H, Aizawa, H, Gray, S, Ishida, KP & Nghiem, LD 2017, 'Role of membrane fouling substances on the rejection of N-nitrosamines by reverse osmosis', Water Research, vol. 118, pp. 187-195.
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The impact of fouling substances on the rejection of four N-nitrosamines by a reverse osmosis (RO) membrane was evaluated by characterizing individual organic fractions in a secondary wastewater effluent and deploying a novel high-performance liquid chromatography-photochemical reaction-chemiluminescence (HPLC-PR-CL) analytical technique. The HPLC-PR-CL analytical technique allowed for a systematic examination of the correlation between the fouling level and the permeation of N-nitrosamines in the secondary wastewater effluent and synthetic wastewaters through an RO membrane. Membrane fouling caused by the secondary wastewater effluent led to a notable decrease in the permeation of N-nitrosodimethylamine (NDMA) while a smaller but nevertheless discernible decrease in the permeation of N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) was also observed. Fluorescence spectrometry analysis revealed that major foulants in the secondary wastewater effluent were humic and fulvic acid-like substances. Analysis using the size exclusion chromatography technique also identified polysaccharides and proteins as additional fouling substances. Thus, further examination was conducted using solutions containing model foulants (i.e., sodium alginate, bovine serum albumin, humic acid and two fulvic acids). Similar to the secondary wastewater effluent, membrane fouling with fulvic acid solutions resulted in a decrease in N-nitrosamine permeation. In contrast, membrane fouling with the other model foulants resulted in a negligible impact on N-nitrosamine permeation. Overall, these results suggest that the impact of fouling on the permeation of N-nitrosamines by RO is governed by specific small organic fractions (e.g. fulvic acid-like organics) in the secondary wastewater effluent.

Gardner, SG, Raina, J-B, Nitschke, MR, Nielsen, DA, Stat, M, Motti, CA, Ralph, PJ & Petrou, K 2017, 'A multi-trait systems approach reveals a response cascade to bleaching in corals', BMC Biology, vol. 15, no. 1, p. 117.
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BACKGROUND: Climate change causes the breakdown of the symbiotic relationships between reef-building corals and their photosynthetic symbionts (genus Symbiodinium), with thermal anomalies in 2015-2016 triggering the most widespread mass coral bleaching on record and unprecedented mortality on the Great Barrier Reef. Targeted studies using specific coral stress indicators have highlighted the complexity of the physiological processes occurring during thermal stress, but have been unable to provide a clear mechanistic understanding of coral bleaching.RESULTS: Here, we present an extensive multi-trait-based study in which we compare the thermal stress responses of two phylogenetically distinct and widely distributed coral species, Acropora millepora and Stylophora pistillata, integrating 14 individual stress indicators over time across a simulated thermal anomaly. We found that key stress responses were conserved across both taxa, with the loss of symbionts and the activation of antioxidant mechanisms occurring well before collapse of the physiological parameters, including gross oxygen production and chlorophyll a. Our study also revealed species-specific traits, including differences in the timing of antioxidant regulation, as well as drastic differences in the production of the sulfur compound dimethylsulfoniopropionate during bleaching. Indeed, the concentration of this antioxidant increased two-fold in A. millepora after the corals started to bleach, while it decreased 70% in S. pistillata.CONCLUSIONS: We identify a well-defined cascading response to thermal stress, demarking clear pathophysiological reactions conserved across the two species, which might be central to fully understanding the mechanisms triggering thermally induced coral bleaching. These results highlight that bleaching is a conserved mechanism, but specific adaptations linked to the coral's antioxidant capacity drive differences in the sensitivity and thus tolerance of each coral spe...

Gardner, SG, Raina, J-B, Ralph, PJ & Petrou, K 2017, 'Reactive oxygen species (ROS) and dimethylated sulphur compounds in coral explants under acute thermal stress', Journal of Experimental Biology, vol. 220, no. 10, pp. 1787-1791.
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Coral bleaching is intensifying with global climate change. While the causes for these catastrophic events are well understood, the cellular mechanism that triggers bleaching is not well established. Our understanding of coral bleaching processes is hindered by the lack of robust methods for studying interactions between host and symbiont at the single-cell level. Here we exposed coral explants to acute thermal stress and measured oxidative stress, more specifically, reactive oxygen species (ROS), in individual symbiont cells. Furthermore, we measured concentrations of dimethylsulphoniopropionate (DMSP) and dimethylsulphoxide (DMSO) to elucidate the role of these compounds in coral antioxidant function. This work demonstrates the application of coral explants for investigating coral physiology and biochemistry under thermal stress and delivers a new approach to study host-symbiont interactions at the microscale, allowing us to directly link intracellular ROS with DMSP and DMSO dynamics.

Ghosh, B, Fatahi, B & Khabbaz, H 2017, 'Analytical Solution to Analyze LTP on Column-Improved Soft Soil Considering Soil Nonlinearity', International Journal of Geomechanics, vol. 17, no. 3, pp. 04016082-04016082.
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© 2016 American Society of Civil Engineers. In this paper, a mechanical model to idealize the load-settlement response of the load transfer platform (LTP) on column-improved soft soil is proposed. This model simultaneously considers the nonlinear and time-dependent stress-strain behavior of soft soil and the negligible tensile strength of the granular material in LTP. The reinforced Timoshenko beam is adopted to model LTP to consider the shear and flexural deformations. Soft soil is idealized by a spring-dashpot system that includes nonlinear and time-dependent behaviors. The columns and geosynthetics are modeled with linear Winkler springs in the applied range of stresses and rough elastic membrane, respectively. The response function of LTP has been derived for distributed pressure loading in the plane strain condition. The principle of superposition is used to solve the fourth-order differential equations. Parametric studies indicate that the spacing of columns, thickness of LTP, degree of consolidation of the soft soil, and tensile stiffness of the geosynthetics significantly affect the behavior of LTP. This study also evaluates the accuracy of using reinforced Timoshenko theory by comparing the results with Pasternak and Euler-Bernoulli theories.

Ghosh, B, Fatahi, B, Khabbaz, H & Yin, J-H 2017, 'Analytical study for double-layer geosynthetic reinforced load transfer platform on column improved soft soil', Geotextiles and Geomembranes, vol. 45, no. 5, pp. 508-536.
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© 2017 The objective of this study is to propose a reasonably accurate mechanical model for double-layer geosynthetic reinforced load transfer platform (LTP) on column reinforced soft soil which can be used by practicing engineers. The developed model is very useful to study the behaviour of LTP resting on soft soil improved with conventional columns such as concrete columns, piles, and deep soil mixing columns. The negligible tensile strength of granular material in LTP, bending and shear deformations of LTP, compressibility and shearing of soft soil have been incorporated in the model. Furthermore, the results from the proposed model simulating the soft soil as Kerr foundation model are compared to the corresponding solutions when the soft soil is idealised by Winkler and Pasternak foundation models. It is observed from the comparison that the presented model can be used as a tool for a better prediction of the LTP behaviour with multi layers of geosynthetics, in comparison with the situation that soft soil is modelled by Winkler and Pasternak foundations. Furthermore, parametric studies show that as the column spacing increases, the maximum deflection of LTP and normalised tension in the geosynthetics also increase. Whereas, the maximum deflection of LTP and normalised tension in the geosynthetics decrease with increasing LTP thickness, stiffness of subsoil, and stiffness of geosynthetic reinforcement. In addition, it is observed that the use of one stronger geosynthetic layer (e.g. 1 × 2000 kN/m) with the equivalent stiffness of two geosynthetic layers (e.g. 2 × 1000 kN/m) does not result in the same settlement of LTP and the tension of the geosynthetic reinforcement when compared to two weaker geosynthetic layers.

Gong, W, Luo, L, Li, W, Luo, X, Liang, H, Ngo, H & Guo, W 2017, 'Using Chemically Enhanced Primary Treatment (CEPT) as a Pretreatment Option for Anaerobic Digestate from Cattle Manure Digestion System', Water, vol. 9, no. 7, pp. 487-487.
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© 2017 by the authors. Anaerobic digestate from cattle manure fermentation may pose a threat to the environment. How to stabilize the digestate's characteristics so that they do not disturb the bio-system is a critical issue for digestate management. Chemically enhanced primary treatment (CEPT) was investigated as a pretreatment option for digestate treatment. The performance of CEPT for digestate management was carried out under rapid mixing (200 r/min) and slow stirring (40 r/min), respectively. The optimal dosage of ferric chloride (FeCl 3 ) was 40 mg/L. The combination of FeCl 3 and anionic polyacrylamide (APAM) had no obvious influence on TP removal, while COD removal efficiency was improved by 15.4%. The digestate pH and temperature remained stable for CEPT application and required no adjustment. The results indicate that CEPT was effective and feasible in enhancing the removal of COD and TP for digestate pretreatment by using FeCl 3 and APAM.

Gong, Y, Gai, L, Tang, J, Fu, J, Wang, Q & Zeng, EY 2017, 'Reduction of Cr(VI) in simulated groundwater by FeS-coated iron magnetic nanoparticles', Science of The Total Environment, vol. 595, pp. 743-751.
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FeS-coated iron (Fe/FeS) magnetic nanoparticles were easily prepared, characterized, and applied for Cr(VI) removal in simulated groundwater. TEM, XRD, and BET characterization tests showed that FeS coating on the surface of Fe0 inhibited the aggregation of Fe0 and that Fe/FeS at a S/Fe molar ratio of 0.207 possessed a large surface area of 62.1m2/g. Increasing the S/Fe molar ratio from 0 to 0.138 decreased Cr(VI) removal by 42.8%, and a further increase to 0.207 enhanced Cr(VI) removal by 63% within 72h. Moreover, Fe/FeS inhibited the leaching of Fe, reducing the toxicity of the particles. Mechanistic analysis indicated that Fe0, Fe2+, and S2- were synergistically involved in the reduction of Cr(VI) to nontoxic Cr(III), which further precipitated as (CrxFe1-x)(OH)3 and Cr(III)-Fe-S. The process of Cr(VI) sorption by Fe/FeS (S/Fe=0.207) was fitted well with a pseudo-second-order kinetic model, and the isotherm data were simulated by Langmuir isotherm model with a maximum sorption capacity of 69.7mg/g compared to 48.9mg/g for Fe0. Low pH and initial Cr(VI) concentration favored Cr(VI) removal. Continuous fixed bed column studies showed that simulated permeable reactive barriers (PRB) with Fe/FeS was considerably effective for in situ removal of Cr(VI) from groundwater. This study demonstrated the high potential of Fe/FeS for Cr(VI) immobilization in water, groundwater, and soil.

Gopinadhan, M, Choo, Y, Kawabata, K, Kaufman, G, Feng, X, Di, X, Rokhlenko, Y, Mahajan, LH, Ndaya, D, Kasi, RM & Osuji, CO 2017, 'Controlling orientational order in block copolymers using low-intensity magnetic fields', Proceedings of the National Academy of Sciences, vol. 114, no. 45, pp. E9437-E9444.
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Significance Magnetic field interactions with condensed matter can produce orientationally ordered states that are important for fundamental research and technological applications. Block copolymer (BCP) mesophases typically exhibit weak field coupling, requiring high-intensity fields generated by superconducting magnets to produce such states. This work advances a strategy for circumventing such field intensity limitations and creates highly aligned mesophases using fields an order of magnitude smaller than typically required and that can be produced by simple permanent magnets. We elucidate the roles of molecular mobility, grain size, and ordering kinetics on the mesophase field response. Low-intensity field-directed BCP ordering has potentially profound implications for processing functional materials and developing complex textures by field shaping.

Goyen, S, Pernice, M, Szabó, M, Warner, ME, Ralph, PJ & Suggett, DJ 2017, 'A molecular physiology basis for functional diversity of hydrogen peroxide production amongst Symbiodinium spp. (Dinophyceae)', Marine Biology, vol. 164, no. 3.
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© 2017, Springer-Verlag Berlin Heidelberg. Hydrogen peroxide (H2O2) production has been demonstrated to play a pivotal role in the photosynthetic stability of higher plants, corals and algae, and considered a primary reactive oxygen species (ROS) associated with the thermal susceptibility of Symbiodinium spp. Here, we simultaneously subjected a large number of Symbiodinium isolates (n = 16) covering broad phylogenetic diversity (clades A, B, D, F) to heat stress and characterized their photosynthetic response via fast repetition rate fluorometry (FRRf) and parallel measurements of H2O2 emissions. Based on their physiological response, isolates clustered into three novel functional groups: (1) thermally tolerant (unchanged photochemical efficiency (Fv/Fm), electron turnover (τQA) or H2O2 emission), or (2) thermally susceptible via decreased Fv/Fm, unchanged τQA, but increased H2O2, indicating energetically uncoupled PSII (thylakoid membrane instability), versus (3) thermally responsive via decreased Fv/Fm, increased τQA and H2O2, indicative of energetically coupled (but downregulated) PSII. There was no correlation between the algal phylogenetic groups and the distribution of isolates amongst these novel functional groups. Two model Symbiodinium isolates for functional groups (1) and (2) (ITS2 type A1, Symbiodinium microadriaticum, and type D1–5, Symbiodinium spp., respectively) were selected to further examine how their different thermal responses corresponded with the expression levels of two genes coding for different metalloforms of superoxide dismutase (MnSOD and NiSOD) that potentially regulate production of H2O2. S. microadriaticum demonstrated the greatest upregulation of MnSOD gene confirming recent suggestions of a role for this metalloform in the antioxidant network associated with thermal stress protection. Assigning Symbiodinium isolates into such functional groups based on coupled molecular-physiological assessment is an important step need...

Guadie, A, Tizazu, S, Melese, M, Guo, W, Ngo, HH & Xia, S 2017, 'Biodecolorization of textile azo dye using Bacillus sp. strain CH12 isolated from alkaline lake', Biotechnology Reports, vol. 15, pp. 92-100.
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© 2017 The Authors Textile azo dye decolorizing bacteria were isolated from alkaline Lakes Abaya and Chamo using Reactive Red 239 (RR239) dye. Through subsequent screening process, strain CH12 was selected to investigate the effects of nutrient supplement, DO, pH, temperature, dye concentration and types on decolorization. Based on 16S rRNA gene sequence analysis, strain CH12 was identified as Bacillus sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) supplements. Complete decolorization was also observed under anoxic and anaerobic conditions, and at the temperature of 30 °C and the pH of 10. However, the azo dye decolorization efficiency of strain CH12 was significantly reduced when NaNO 3 (1–8%) was supplemented or under aerobic culturing condition (≤6%), indicating that RR239 was less preferred electron acceptor. Overall, strain CH12 can be a promising candidate for decolorization applications due to its potential to effectively decolorize higher RR239 concentrations (50−250 mg/L) and six additional dyes.

Gulzar, M, Masjuki, HH, Alabdulkarem, A, Kalam, MA, Varman, M, Zulkifli, NWM, Zahid, R & Yunus, R 2017, 'Chemically active oil filter to develop detergent free bio-based lubrication for diesel engine', Energy, vol. 124, pp. 413-422.
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Guo, J, Ni, B-J, Han, X, Chen, X, Bond, P, Peng, Y & Yuan, Z 2017, 'Data on metagenomic profiles of activated sludge from a full-scale wastewater treatment plant', Data in Brief, vol. 15, pp. 833-839.
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© 2017 The Authors The data in this article mainly present the sequences of activated sludge from a full-scale municipal wastewater treatment plant (WWTP) carrying out simultaneous nitrogen and phosphorous removal in Beijing, China. Data include the operational conditions and performance, dominant microbes and taxonomic analysis in this WWTP, and function annotation results based on SEED, Clusters of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Sequencing data were generated by using Illumina HiSeq. 2000 platform according to the recommendations of the manufacturer. The sequencing data have been deposited in MG-RAST server (project ID: mgm4735473.3). For more information, see “Unraveling microbial structure and diversity of activated sludge in a full-scale simultaneous nitrogen and phosphorus removal plant using metagenomic sequencing” by Guo et al. (2017) [1].

Guo, J, Ni, B-J, Han, X, Chen, X, Bond, P, Peng, Y & Yuan, Z 2017, 'Unraveling microbial structure and diversity of activated sludge in a full-scale simultaneous nitrogen and phosphorus removal plant using metagenomic sequencing', Enzyme and Microbial Technology, vol. 102, pp. 16-25.
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© 2017 Activated sludge contains highly complex microbial communities, which play crucial roles in pollutant removal performance in wastewater treatment plants (WWTPs). Metagenomic sequencing was applied to characterize microbial community and functional profiles within activated sludge from a full-scale municipal WWTP carrying out simultaneous nitrogen and phosphorous removal (SNPR). We applied the assembled contigs (N90 of 591 bp) and predicted genes to conduct taxonomic and function annotations, respectively. Results revealed the extraordinary microbial diversity of activated sludge, which included detection of minority populations that are difficult to be explored by traditional molecular methods. Taxonomic analysis indicated that the dominant bacterial phyla were Proteobacteria, Nitrospirae, Bacteroidetes, Actinobacteria and Firmicutes. The abundance of the key organisms involved in nitrogen and phosphorous removal were qualified. Aerobic ammonia-oxidizing bacteria distinctly dominate over ammonia-oxidizing archaea and anaerobic ammonium oxidation bacteria. Various key enzymes involved in the global nitrogen cycle were annotated in the activated sludge. High abundance of the known polyphosphate accumulating organisms was detected (approximately 4.89% of the overall population reads), supporting good phosphorous removal performance. This study provides a comprehensive insight into the community structure and diversity of the SNPR system, and will provide foundation for optimal operation of nutrient removal systems.

Hanif, M, Mahlia, TMI, Aditiya, HB & Abu Bakar, MS 2017, 'Energy and environmental assessments of bioethanol production from Sri Kanji 1 cassava in Malaysia', Biofuel Research Journal, vol. 4, no. 1, pp. 537-544.
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© 2017 BRTeam. According to the Malaysia's biofuel policy, renewable fuels are crucial for energy sustainability in the transportation sector in the future. This study was aimed to evaluate the potential of bioethanol production from Sri Kanji 1 cassava in Malaysia in terms of energy efficiency and renewability, as well to estimate the potential greenhouse gas (GHG) emissions reduction in CO2 equivalent. Bioethanol production process from cassava includes cassava farming, ethanol production, and transportation in which the primary energy consumption was considered. The Net Energy Balance (NEB) and Net Energy Ratio (NER) of 25.68 MJ/L and 3.98, respectively, indicated that bioethanol production from Sri Kanji 1 cassava in Malaysia was energy efficient. From the environmental perspective, the GHG balance results revealed that the production and distribution of 1 L of Cassava Fuel Ethanol (CFE) could reduce GHG emissions by 73.2%. Although found promising in the present study, Sri Kanji 1 cassava as bioethanol feedstock should be further investigated by constructing an actual ethanol plant to obtain real life data.

Ho, L & Fatahi, B 2017, 'Axisymmetric Consolidation in Unsaturated Soil Deposit Subjected to Time-Dependent Loadings', International Journal of Geomechanics, vol. 17, no. 2, pp. 04016046-04016046.
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© 2016 American Society of Civil Engineers. This paper presents an analytical solution to predict the axisymmetric consolidation in unsaturated soil deposits subjected to different time-dependent loadings. The mathematical procedure uses the separation of variables and Laplace transformation methods to obtain the final solution. A set of polar governing equations of flow are obtained and presented under the partial differential equations (PDEs), and then the variable separation technique is used to alter the PDEs to ordinary differential equations (ODEs) consisting of distinctive variables. Fourier Bessel and sine series are used to present functions of radial and vertical flows, respectively, and the Laplace transformation is used to obtain a function of time. Four primary time-dependent loading functions, including ramping, asymptotic, sinusoid, and damped sine wave, are mathematically simulated and incorporated into the proposed solutions. This study investigates changes in excess pore-air and pore-water pressures as well as consolidation settlement against the air-to-water permeability ratio and various loading parameters. Moreover, changes in suction and net stress induced by ramped and asymptotic loadings are also presented in the worked examples.

Hossain, N, Haji Zaini, J & Mahlia, TMI 2017, 'A Review of Bioethanol Production from Plant-based Waste Biomass by Yeast Fermentation', International Journal of Technology, vol. 8, no. 1, pp. 5-5.
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© IJTech 2017. Commercialization of bioethanol has recently intensified due to its market stability, low cost, sustainability, alternative fuel energy composition, greener output and colossal fossil fuel depletion. Recently, because of greenhouse intensity worldwide, many researches are ongoing to reprocess the waste as well as turning down the environmental pollution. With this scenario, the invention of bioethanol was hailed as a great accomplishment to transform waste biomass to fuel energy and in turn reduce the massive usages of fossil fuels. In this study, our review enlightens various sources of plant-based waste feed stocks as the raw materials for bioethanol production because they do not adversely impact the human food chain. However, the cheapest and conventional fermentation method, yeast fermentation is also emphasized here notably for waste biomass-to-bioethanol conversion. Since the key fermenting agent, yeast is readily available in local and international markets, it is more cost-effective in comparison with other fermentation agents. Furthermore, yeast has genuine natural fermentation capability biologically and it produces zero chemical waste. This review also concerns a detailed overview of the biological conversion processes of lignocellulosic waste biomass-to-bioethanol, the diverse performance of different types of yeasts and yeast strains, plusbioreactor design, growth kinetics of yeast fermentation, environmental issues, integrated usages on modern engines and motor vehicles, as well as future process development planning with some novel co-products.

Hossain, N, Jalil, R, Mahlia, TMI & Zaini, J 2017, 'Calorific Value Analysis of Azadirachta Excelsa and Endospermum Malaccense as Potential Solid Fuels Feedstock', International Journal of Technology, vol. 8, no. 4, pp. 634-634.
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© IJTech 2017. Thermal conversion of woody biomass to fuel has been intensified in recent decades due to the depletion of fossil fuels, greenhouse effect and high energy demand worldwide. Screening the potential feedstock is being considered as one of the alternatives to identifying the most suitable biomass resources prior to being converted into renewable energy in the form of solid fuels, such as charcoal and briquettes. Generally, high calorific value (CV) indicates high potential of feedstock for briquettes, torrefied wood and coal generation. In this study, CV was characterized using a bomb calorimeter that was based on 3 different ranges of moisture content (MC) that are > 25%, 20%-25% and < 20% for two tropical tree species, namely Azadirachta excelsa (Sentang) and Endospermum malaccense (Sesenduk), respectively. This standard method for the characterization process was considered to determine the CV. Average CV for both samples ranged between 16-17 MJ/kg. The highest CV was 17.3490 MJ/kg and 17.1273 MJ/kg for Sesenduk and Sentang, respectively and calorific values were obtained at MC less than 20%. The experimental study demonstrated that the decreasing value of MC has increased the CV because of the high value of oxygen-to-carbon (O/C) ratio in the wood; additionally, the energy density of the wood sample was also improved when CV increased. Both of these species were proved to contain the potential of being feedstock as wood fuel resources, since they carry standard CVs, obtain fast growth with suitable conditions in Malaysia and are grown at very low cost of production for plantations, fertilizer, pesticides, labor, transportation and handling.

Hu, Y, Wang, XC, Sun, Q, Ngo, HH, Yu, Z, Tang, J & Zhang, Q 2017, 'Characterization of a hybrid powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) process with high flux by gravity flow: Operational performance and sludge properties', Bioresource Technology, vol. 223, pp. 65-73.
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Three PAC-DMBRs were developed for wastewater treatment under different PAC dosages with biomass concentrations averaged at 2.5, 3.5 and 5.0g/L. The DMBRs could be continuously operated at 40-100L/m(2)h, while higher fluxes were obtained within the PAC-DMBRs with hydraulic retention times varying in 4-10h. A dose of 1g/L PAC brought about obvious improvement in the sludge particle size distribution, settling, flocculating and dewatering properties due to the formation of biological PAC, and the sludge properties were further improved at a higher PAC dose (3g/L). The addition of PAC notably shortened the DM formation time after air backwashing and enhanced pollutant removal. Moreover, under a long solid retention time (approximately 150d), the concentrations of both soluble and bound extracellular polymeric substances (EPS) decreased substantially because of the adsorption and biodegradation effects of the biological PAC. No obvious impact on biomass activity was observed with PAC addition.

Hu, Y, Yang, Y, Wang, XC, Hao Ngo, H, Sun, Q, Li, S, Tang, J & Yu, Z 2017, 'Effects of powdered activated carbon addition on filtration performance and dynamic membrane layer properties in a hybrid DMBR process', Chemical Engineering Journal, vol. 327, pp. 39-50.
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© 2017 Elsevier B.V. A powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) was developed and used to treat domestic wastewater by dosing with 3 g/L PAC. The experimental results were compared with those of a control DMBR to investigate the filtration performance and various properties of the dynamic membrane (DM) layer. One flat-sheet DM module made of nylon mesh (pore size 75 μm) was used for effluent production at a high stable flux (50–100 L/m 2  h) under a 10 cm water head by gravity flow, resulting in continuous operation cycles of 60–120 h. During the operation period, the PAC-DMBR showed enhanced removal efficiency of pollutants, higher stable membrane flux (10 L/m 2  h more), lower filtration resistance (6.0–8.0 × 10 10  m −1 ), quicker formation of the DM layer (within 5 min), and better DM layer regeneration after air backwashing. The DM layer in the PAC-DMBR showed a more porous and incompressible structure, because less extracellular polymeric substance and a portion of the biological PAC were incorporated into the DM layer formed as verified by the analytical results. Using high-throughput pyrosequencing technology, it was revealed that at the genus level the diversity of bacterial communities increased from 18 to 23 genera, while several genera that were favored in the PAC-assisted environment or were responsible for degrading complex organics were enriched. Moreover, the abundance of phylum Proteobacteria, which served as pioneer surface colonizers, was reduced in the PAC-DMBR. It was concluded that PAC addition could modify various aspects of the activated sludge and the DM layer properties, which affected the filtration behavior of the DM layer in the PAC-DMBR.

Imdadul, HK, Masjuki, HH, Kalam, MA, Zulkifli, NWM, Kamruzzaman, M, Shahin, MM & Rashed, MM 2017, 'Evaluation of oxygenated n-butanol-biodiesel blends along with ethyl hexyl nitrate as cetane improver on diesel engine attributes', Journal of Cleaner Production, vol. 141, pp. 928-939.
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Imdadul, HK, Rashed, MM, Shahin, MM, Masjuki, HH, Kalam, MA, Kamruzzaman, M & Rashedul, HK 2017, 'Quality improvement of biodiesel blends using different promising fuel additives to reduce fuel consumption and NO emission from CI engine', Energy Conversion and Management, vol. 138, pp. 327-337.
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Imdadul, HK, Zulkifli, NWM, Masjuki, HH, Kalam, MA, Kamruzzaman, M, Rashed, MM, Rashedul, HK & Alwi, A 2017, 'Experimental assessment of non-edible candlenut biodiesel and its blend characteristics as diesel engine fuel', Environmental Science and Pollution Research, vol. 24, no. 3, pp. 2350-2363.
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Jamshidi Chenari, R, Fatahi, B, Akhavan Maroufi, MA & Alaie, R 2017, 'An Experimental and Numerical Investigation into the Compressibility and Settlement of Sand Mixed with TDA', Geotechnical and Geological Engineering, vol. 35, no. 5, pp. 2401-2420.
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A series of large scale oedometer experiments were carried out to investigate the settlement of sand reinforced with tire derived aggregates (TDA). The parameters studied were five different amounts of TDAs, three aspect ratios and relative skeletal densities, and seven overburden pressures. The volume compressibility coefficient was calculated against different input parameters, and the constraint condition used enabled Poisson’s ratio to be calculated from an “at-rest” coefficient of earth pressure. The triaxial modulus was calculated indirectly and then adopted in subsequent numerical analyses. Finite element analysis and Monte Carlo simulations were used to investigate the settlement of this mixture and to study how the different parameters affected the settlement mixtures of sand and TDAs. The experimental and numerical results reveal that the amount of TDAs is the major parameter which affects settlement, although the overburden pressure and relative skeletal density are also important. The aspect ratio of the shred has almost no effect on volume compressibility parameters as long as constraint compression condition governs. Two index parameters were defined to discuss the type of shred distribution and how it affects settlement of the mixture.

Jeong, S, Cho, K, Jeong, D, Lee, S, Leiknes, T, Vigneswaran, S & Bae, H 2017, 'Effect of engineered environment on microbial community structure in biofilter and biofilm on reverse osmosis membrane', Water Research, vol. 124, pp. 227-237.
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© 2017 Elsevier Ltd Four dual media filters (DMFs) were operated in a biofiltration mode with different engineered environments (DMF I and II: coagulation with/without acidification and DMF III and IV: without/with chlorination). Designed biofilm enrichment reactors (BERs) containing the removable reverse osmosis (RO) coupons, were connected at the end of the DMFs in parallel to analyze the biofilm on the RO membrane by DMF effluents. Filtration performances were evaluated in terms of dissolved organic carbon (DOC) and assimilable organic carbon (AOC). Organic foulants on the RO membrane were also quantified and fractionized. The bacterial community structures in liquid (seawater and effluent) and biofilm (DMF and RO) samples were analyzed using 454-pyrosequencing. The DMF IV fed with the chlorinated seawater demonstrated the highest reductions of DOC including LMW-N as well as AOC among the other DMFs. The DMF IV was also effective in reducing organic foulants on the RO membrane surface. The bacterial community structure was grouped according to the sample phase (i.e., liquid and biofilm samples), sampling location (i.e., DMF and RO samples), and chlorination (chlorinated and non-chlorinated samples). In particular, the biofilm community in the DMF IV differed from the other DMF treatments, suggesting that chlorination exerted as stronger selective pressure than pH adjustment or coagulation on the biofilm community. In the DMF IV, several chemoorganotrophic chlorine-resistant biofilm-forming bacteria such as Hyphomonas, Erythrobacter, and Sphingomonas were predominant, and they may enhance organic carbon degradation efficiency. Diverse halophilic or halotolerant organic degraders were also found in other DMFs (i.e., DMF I, II, and III). Various kinds of dominant biofilm-forming bacteria were also investigated in RO membrane samples; the results provided possible candidates that cause biofouling when DMF process is applied as the pretreatment option for...

Jia, H, Yang, G, Ngo, H-H, Guo, W, Zhang, H, Gao, F & Wang, J 2017, 'Enhancing simultaneous response and amplification of biosensor in microbial fuel cell-based upflow anaerobic sludge bed reactor supplemented with zero-valent iron', Chemical Engineering Journal, vol. 327, pp. 1117-1127.
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© 2017 Elsevier B.V. The development of a convenient and sensitive sensor such as a microbial fuel cell (MFC) to monitor the operation of upflow anaerobic sludge blanket (UASB) is indispensable. However, the biosensor's properties were affected due to excessive acidification and suffocation of the electron transport. In this study, zero-valent iron (ZVI) was applied to restrain excessive acidification and improve the sensing performance. According to the results, the response rate of electrical signal accumulated with the addition of ZVI compared to the control reactor. As well as the electrical signal amplified and the subsidence rate maximum reached 0.059 V/h with 30 mg/L ZVI added that 883% higher than the control one during the stage (COD concentration 500 mg/L–1000 mg/L). With the electrochemical analysis, the internal resistance of ZVI-UASB-MFC decreased and redox activity promoted effectively with ZVI added. During the overloading phase, the fractional content of butyric acid changed from 53% to 31%, while that of acetic acid rose from 18% to 39% after 30 mg/L ZVI addition. These results indicated that adding ZVI to the digestion could retard excessive acidification by promoting butyric acid conversion and accumulating direct interspecies electron transfer simultaneous for enhancing the biosensor's performance. According to the Fe 2+ and Fe 3+ of effluent were 2.25 mg/L and 0.39 mg/L with 50 mg/L ZVI addition, moderate amount of ZVI was effective for system and safety to the environment. It might helpfully provide a promising way to enhance biosensing.

Jiang, Z, Kumar, M, Padula, MP, Pernice, M, Kahlke, T, Kim, M & Ralph, PJ 2017, 'Development of an Efficient Protein Extraction Method Compatible with LC-MS/MS for Proteome Mapping in Two Australian Seagrasses Zostera muelleri and Posidonia australis', Frontiers in Plant Science, vol. 8, pp. 1-14.
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© 2017 Jiang, Kumar, Padula, Pernice, Kahlke, Kim and Ralph. The availability of the first complete genome sequence of the marine flowering plant Zostera marina (commonly known as seagrass) in early 2016, is expected to significantly raise the impact of seagrass proteomics. Seagrasses are marine ecosystem engineers that are currently declining worldwide at an alarming rate due to both natural and anthropogenic disturbances. Seagrasses (especially species of the genus Zostera) are compromised for proteomic studies primarily due to the lack of efficient protein extraction methods because of their recalcitrant cell wall which is rich in complex polysaccharides and a high abundance of secondary metabolites in their cells. In the present study, three protein extraction methods that are commonly used in plant proteomics i.e., phenol (P); trichloroacetic acid/acetone/SDS/phenol (TASP); and borax/polyvinyl-polypyrrolidone/phenol (BPP) extraction, were evaluated quantitatively and qualitatively based on two dimensional isoelectric focusing (2D-IEF) maps and LC-MS/MS analysis using the two most abundant Australian seagrass species, namely Zostera muelleri and Posidonia australis. All three tested methods produced high quality protein extracts with excellent 2D-IEF maps in P. australis. However, the BPP method produces better results in Z. muelleri compared to TASP and P. Therefore, we further modified the BPP method (M-BPP) by homogenizing the tissue in a modified protein extraction buffer containing both ionic and non-ionic detergents (0.5% SDS; 1.5% Triton X-100), 2%PVPPand protease inhibitors. Further, the extracted proteins were solubilized in 0.5%of zwitterionic detergent (C7BzO) instead of 4%CHAPS. This slight modification to the BPP method resulted in a higher protein yield, and good quality 2-DE maps with a higher number of protein spots in both the tested seagrasses. Further, the M-BPP method was successfully utilized in western-blot analysis of phosphoe...

Kalaruban, M, Loganathan, P, Kandasamy, J, Naidu, R & Vigneswaran, S 2017, 'Enhanced removal of nitrate in an integrated electrochemical-adsorption system', Separation and Purification Technology, vol. 189, pp. 260-266.
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© 2017 Elsevier B.V. The electrochemical (EC) method of removing pollutants in water is a widely used process in water and wastewater treatment. An EC-adsorption integrated system was investigated to test whether the simultaneous removal of nitrate by the two processes would be better than removal utilising the individual EC and adsorption methods. In the integrated system, an adsorbent (ion exchange resin - Dowex 21k XLT) was placed inside a stainless steel box that served as an anode with a Cu plate as cathode. In an experiment using 2 L nitrate solution containing 20 mg N/L and 2 g adsorbent the rate of nitrate removal in the integrated system was initially fast with 35% removed in 30 min, though slowing down later. The rate of removal increased with increasing current, voltage and pH up to 7 but decreased as the distance between the electrodes also increased. The optimum nitrate removal of 67% was obtained at pH 7, 1 A, and 31 V for a distance of 1 cm between the electrodes after 180 min. The amount of nitrate removed fell when sulphate was present in the integrated system due to sulphate competing with nitrate for adsorption. Concentration of ammonium produced by nitrate reduction in the EC system was reduced in the presence of adsorbent. Nitrate removal in the integrated system is approximately equal to the sum of the removals in the two individual processes.

Kang, Y, Zhang, J, Xie, H, Guo, Z, Ngo, HH, Guo, W & Liang, S 2017, 'Enhanced nutrient removal and mechanisms study in benthic fauna added surface-flow constructed wetlands: The role of Tubifex tubifex', Bioresource Technology, vol. 224, pp. 157-165.
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This study designed a combined benthic fauna-T. orientalis-substrate-microbes surface-flow constructed wetlands (SFCWs) through the addition of T. tubifex. Results showed that, the removal efficiencies of nitrogen and phosphorus in the tested SFCWs achieved 81.14±4.16% and 70.49±7.60%, which were 22.27% and 27.35% higher than that without T. tubifex. Lower nitrate (2.11±0.79mg/L) and ammonium (0.75±0.64mg/L) were also observed in the tested SFCWs, which were 3.46mg/L and 0.52mg/L lower than that without T. tubifex. Microbial study confirmed the increased denitrifiers with T. tubifex. The lower nitrogen in effluent was also attributed to higher contents of nitrogen storage in sediment and T. orientalis due to the bioturbation of T. tubifex. Furthermore, with T. tubifex, higher proportions of particulate (22.66±3.96%) and colloidal phosphorus (20.57±3.39%) observed promoted phosphorus settlement and further absorption by T. orientalis. The outcomes of this study provides an ecological and economical strategy for improving the performance of SFCWs.

Kaufman, G, Liu, W, Williams, DM, Choo, Y, Gopinadhan, M, Samudrala, N, Sarfati, R, Yan, ECY, Regan, L & Osuji, CO 2017, 'Flat Drops, Elastic Sheets, and Microcapsules by Interfacial Assembly of a Bacterial Biofilm Protein, BslA', Langmuir, vol. 33, no. 47, pp. 13590-13597.
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Kelleway, JJ, Saintilan, N, Macreadie, PI, Baldock, JA & Ralph, PJ 2017, 'Sediment and carbon deposition vary among vegetation assemblages in a coastal salt marsh', Biogeosciences, vol. 14, no. 16, pp. 3763-3779.
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Abstract. Coastal salt marshes are dynamic, intertidal ecosystems that are increasingly being recognised for their contributions to ecosystem services, including carbon (C) accumulation and storage. The survival of salt marshes and their capacity to store C under rising sea levels, however, is partially reliant upon sedimentation rates and influenced by a combination of physical and biological factors. In this study, we use several complementary methods to assess short-term (days) deposition and medium-term (months) accretion dynamics within a single marsh that contains three salt marsh vegetation types common throughout southeastern (SE) Australia.We found that surface accretion varies among vegetation assemblages, with medium-term (19 months) bulk accretion rates in the upper marsh rush (Juncus) assemblage (1.74 ± 0.13 mm yr−1) consistently in excess of estimated local sea-level rise (1.15 mm yr−1). Accretion rates were lower and less consistent in both the succulent (Sarcocornia, 0.78 ± 0.18 mm yr−1) and grass (Sporobolus, 0.88 ± 0.22 mm yr−1) assemblages located lower in the tidal frame. Short-term (6 days) experiments showed deposition within Juncus plots to be dominated by autochthonous organic inputs with C deposition rates ranging from 1.14 ± 0.41 mg C cm−2 d−1 (neap tidal period) to 2.37 ± 0.44 mg C cm−2 d−1 (spring tidal period), while minerogenic inputs and lower C deposition dominated Sarcocornia (0.10 ± 0.02 to 0.62 ± 0.08 mg C cm−2 d−1) and Sporobolus (0.17 ± 0.04 to 0.40 ± 0.07 mg C cm−2 d−1) assemblages.Elemental (C : N), isotopic (δ13C), mid-infrared (MIR) and 13C nuclear magnetic resonance (NMR) analyses revealed little difference in either the source or character of materials being deposited among neap versus spring tidal periods. Instead, these analyses point to substantial redistribution of materials within the Sarcocornia and Sporobolus assemblages, compared to high retention and preservation of organic inputs in the Juncus...

Kelleway, JJ, Saintilan, N, Macreadie, PI, Baldock, JA, Heijnis, H, Zawadzki, A, Gadd, P, Jacobsen, G & Ralph, PJ 2017, 'Geochemical analyses reveal the importance of environmental history for blue carbon sequestration', Journal of Geophysical Research: Biogeosciences, vol. 122, no. 7, pp. 1789-1805.
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©2017. American Geophysical Union. All Rights Reserved. Coastal habitats including saltmarshes and mangrove forests can accumulate and store significant blue carbon stocks, which may persist for millennia. Despite this implied stability, the distribution and structure of intertidal-supratidal wetlands are known to respond to changes imposed by geomorphic evolution, climatic, sea level, and anthropogenic influences. In this study, we reconstruct environmental histories and biogeochemical conditions in four wetlands of similar contemporary vegetation in SE Australia. The objective is to assess the importance of historic factors to contemporary organic carbon (C) stocks and accumulation rates. Results from the four cores—two collected from marine-influenced saltmarshes (Wapengo marine site (WAP-M) and Port Stephens marine site (POR-M)) and two from fluvial influenced saltmarshes (Wapengo fluvial site (WAP-F) and Port Stephens fluvial site (POR-F))—highlight different environmental histories and preservation conditions. High C stocks are associated with the presence of a mangrove phase below the contemporary saltmarsh sediments in the POR-M and POR-F cores. 13C nuclear magnetic resonance analyses show this historic mangrove root C to be remarkably stable in its molecular composition despite its age, consistent with its position in deep sediments. WAP-M and WAP-F cores did not contain mangrove root C; however, significant preservation of char C (up to 46% of C in some depths) in WAP-F reveals the importance of historic catchment processes to this site. Together, these results highlight the importance of integrating historic ecosystem and catchment factors into attempts to upscale C accounting to broader spatial scales.

Khan, MH, Jamali, SS, Lyalin, A, Molino, PJ, Jiang, L, Liu, HK, Taketsugu, T & Huang, Z 2017, 'Atomically Thin Hexagonal Boron Nitride Nanofilm for Cu Protection: The Importance of Film Perfection', Advanced Materials, vol. 29, no. 4, pp. 1-7.
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Outstanding protection of Cu by high-quality boron nitride nanofilm (BNNF) 1-2 atomic layers thick in salt water is observed, while defective BNNF accelerates the reaction of Cu toward water. The chemical stability, insulating nature, and impermeability of ions through the BN hexagons render BNNF a great choice for atomic-scale protection.

Khan, MH, Liu, HK, Sun, X, Yamauchi, Y, Bando, Y, Golberg, D & Huang, Z 2017, 'Few-atomic-layered hexagonal boron nitride: CVD growth, characterization, and applications', Materials Today, vol. 20, no. 10, pp. 611-628.
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© 2017 Two-dimensional (2D) materials have shown outstanding properties that make them the materials of choice for future semiconductor and flexible nanoelectronics. Hexagonal boron nitride nanosheet (BNNS) is one of the most studied 2D materials due to its extraordinary properties and potential applications. The synthesis of large, homogeneous, and few-layered BNNS, however, remains challenging. Among the various synthetic routes, chemical vapour deposition (CVD) is preferred on the grounds of its potential to yield large BNNS with controllable atomic layers and minimal contamination. We thus devote this review to the CVD growth of BNNS, and its characterization and applications. The recent progresses in the CVD growth of BNNS is firstly summarized from the aspects of precursors, substrates, growth mechanisms, and transfer techniques. This review then moves on to the characterization of few-atomic-layered h-BN sheets, covering a variety of microscopic and spectroscopic techniques that have proved useful for assessing the quality of BNNS. The applications of the BNNS are also summarized. This review is expected to instigate new methods and improvements in relation to the CVD growth of BNNS, which has enabled exceptional performance as a key component of nanoscale electronics.

Kim, J, Blandin, G, Phuntsho, S, Verliefde, A, Le-Clech, P & Shon, H 2017, 'Practical considerations for operability of an 8″ spiral wound forward osmosis module: Hydrodynamics, fouling behaviour and cleaning strategy', Desalination, vol. 404, pp. 249-258.
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© 2016 Elsevier B.V. A better understanding of large spiral wound forward osmosis (SW FO) module operation is needed to provide practical insight for a full-scale FO practical implementation desalination plant. Therefore, this study investigated two different 8″ SW FO modules (i.e. cellulose tri acetate, CTA and thin film composite, TFC) in terms of hydrodynamics, operating pressure, water and solute fluxes, fouling behaviour and cleaning strategy. For both modules, a significantly lower flow rate was required in the draw channel than in the feed channel due to important pressure-drop in the draw channel and was a particularly critical operating challenge in the CTA module when permeate spacers are used. Under FO and pressure assisted osmosis (PAO, up to 2.5 bar) operations, the TFC module featured higher water flux and lower reverse salt flux than the CTA module. For both modules, fouling tests demonstrated that feed inlet pressure was more sensitive to foulant deposition than the flux, thus confirming that FO fouling deposition occurs in the feed channel rather than on the membrane surface. Osmotic backwash combined with physical cleaning used in this study confirmed to be effective and adapted to large-scale FO module operation.

Kim, JE, Phuntsho, S, Chekli, L, Hong, S, Ghaffour, N, Leiknes, T, Choi, JY & Shon, HK 2017, 'Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system', Desalination, vol. 416, pp. 76-85.
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© 2017 Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration (UF) as a pre-treatment process. The results showed that the FDFO-NF hybrid system using thin film composite forward osmosis (TFC) FO membrane has less environmental impact than conventional RO hybrid systems due to lower consumption of energy and cleaning chemicals. The energy requirement for the treatment of mine impaired water by the FDFO-NF hybrid system was 1.08 kWh/m3, which is 13.6% less energy than an MF-RO and 21% less than UF-RO under similar initial feed solution. In a closed-loop system, the FDFO-NF hybrid system using a TFC FO membrane with an optimum NF recovery rate of 84% had the lowest unit operating expenditure of AUD $0.41/m3. Besides, given the current relatively high price and low flux performance of the cellulose triacetate and TFC FO membranes, the FDFO-NF hybrid system still holds opportunities to reduce operating expenditure further. Optimizing NF recovery rates and improving the water flux of the membrane would decrease the unit OPEX costs, although the TFC FO membrane would be less sensitive to this effect.

Kim, Y, Li, S, Chekli, L, Phuntsho, S, Ghaffour, N, Leiknes, T & Shon, HK 2017, 'Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis – ultrafiltration bioreactor', Bioresource Technology, vol. 240, pp. 149-156.
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© 2017 Elsevier Ltd In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55 days. The FDFO performance was first investigated in terms of flux decline with various fertilizers draw solution. Flux decline was very severe with all fertilizers due to the absence of aeration and the sticky property of sludge. Flux recovery by physical cleaning varied significantly amongst tested fertilizers which seriously affected biofouling in FDFO via reverse salt flux (RSF). Besides, RSF had a significant impact on nutrient accumulation in the bioreactor. These results indicated that nutrient accumulation negatively influenced the anaerobic activity. To elucidate these phenomena, bacterial and archaeal community structures were analyzed by pyrosequencing. Results showed that bacterial community structure was affected by fertilizer properties with less impact on archaeal community structure, which resulted in a reduction in biogas production and an increase in nitrogen content.

Kim, Y, Li, S, Chekli, L, Woo, YC, Wei, C-H, Phuntsho, S, Ghaffour, N, Leiknes, T & Shon, HK 2017, 'Assessing the removal of organic micro-pollutants from anaerobic membrane bioreactor effluent by fertilizer-drawn forward osmosis', Journal of Membrane Science, vol. 533, pp. 84-95.
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© 2017 Elsevier B.V. In this study, the behavior of organic micro-pollutants (OMPs) transport including membrane fouling was assessed in fertilizer-drawn forward osmosis (FDFO) during treatment of the anaerobic membrane bioreactor (AnMBR) effluent. The flux decline was negligible when the FO membrane was oriented with active layer facing feed solution (AL-FS) while severe flux decline was observed with active layer facing draw solution (AL-DS) with di-ammonium phosphate (DAP) fertilizer as DS due to struvite scaling inside the membrane support layer. DAP DS however exhibited the lowest OMPs forward flux or higher OMPs rejection rate compared to other two fertilizers (i.e., mono-ammonium phosphate (MAP) and KCl). MAP and KCl fertilizer DS had higher water fluxes that induced higher external concentration polarization (ECP) and enhanced OMPs flux through the FO membrane. Under the AL-DS mode of membrane orientation, OMPs transport was further increased with MAP and KCl as DS due to enhanced concentrative internal concentration polarization while with DAP the internal scaling enhanced mass transfer resistance thereby lowering OMPs flux. Physical or hydraulic cleaning could successfully recover water flux for FO membranes operated under the AL-FS mode but only partial flux recovery was observed for membranes operated under AL-DS mode because of internal scaling and fouling in the support layer. Osmotic backwashing could however significantly improve the cleaning efficiency.

Kim, Y, Woo, YC, Phuntsho, S, Nghiem, LD, Shon, HK & Hong, S 2017, 'Evaluation of fertilizer-drawn forward osmosis for coal seam gas reverse osmosis brine treatment and sustainable agricultural reuse', Journal of Membrane Science, vol. 537, pp. 22-31.
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© 2017 Elsevier B.V. The fertilizer-drawn forward osmosis (FDFO) was investigated for treating coal seam gas (CSG) produced water to generate nutrient rich solution for irrigation. Its performance was evaluated and compared with reverse osmosis (RO) in terms of specific energy consumption (SEC) and nutrient concentrations in the final product water. The RO-FDFO hybrid process was developed to further improve FDFO. The results showed that FDFO has the lowest SEC followed by the RO-FDFO and RO processes. The final nutrient concentration simulation demonstrated that the RO-FDFO hybrid process has lower final concentration, higher maximum recovery and lower nutrient loss than the stand alone FDFO process. Therefore, it was suggested that the RO-FDFO is the most effective treatment option for CSG produced water as well as favourable nutrient supply. Lastly, membrane fouling mechanism was examined in CSG RO brine treatment by FDFO, and the strategies for controlling fouling were critically evaluated. KNO3 exhibited the highest flux decline corresponding to the highest reverse salt flux, while the most severe membrane scaling was observed with calcium nitrate, primarily due to the reverse transport of calcium ions. To control membrane fouling in FDFO process, both physical flushing and chemical cleaning were examined. Membrane cleaning with citric acid of 5% resulted in a complete flux recovery.

Kook, S, Kim, J, Kim, S-J, Lee, J, Han, D, Phuntsho, S, Shim, W-G, Hwang, M, Shon, HK & Kim, IS 2017, 'Effect of initial feed and draw flowrates on performance of an 8040 spiral-wound forward osmosis membrane element', DESALINATION AND WATER TREATMENT, vol. 72, pp. 1-12.
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© 2017, Desalination Publications. All rights reserved. This study investigated the effects of initial feed (20–50 L/min) and draw flowrates (2–5 L/min) on 8040 spiral-wound FO element performances in serial configuration for a forward osmosis and reverse osmosis (FO-RO) hybrid system employing single element-based tests. Average Jw,ave values for varying feed and draw flowrates were found to be 20.93, 19.38 and 18.71 LMH at E1, E2 and E3 (first, second and third elements in a serial configuration), respectively, with averaged diluted draw concentrations of 12.55, 7.88 and 5.77 g/L (initial conc. = 35 g/L). The draw stream dilution was not governed by Jw,ave but by the initial draw flowrates at the inlet that governs the retention time of the draw water body in the element. To sum up the performance results, it was concluded that initial draw flowrate is found to govern the performances of FO elements in series in terms of both production of diluted draw stream, determined by the averaged water flux of the FO element, Jw,ave, and the degree of draw stream dilution. Specific energy consumptions (SECs) of RO were estimated with varying RO feed concentrations (i.e. diluted draw concentration); it was observed the efficiency of SEC reduction by the dilution significantly decays after a critical RO recovery rate. This study successfully provides a valuable insight for feasible application of the FO-RO hybrid system.

Kumar, M, Padula, MP, Davey, P, Pernice, M, Jiang, Z, Sablok, G, Contreras-Porcia, L & Ralph, PJ 2017, 'Proteome Analysis Reveals Extensive Light Stress-Response Reprogramming in the Seagrass Zostera muelleri (Alismatales, Zosteraceae) Metabolism', Frontiers in Plant Science, vol. 7, pp. 1-19.
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© 2017, Kumar, Padula, Davey, Pernice, Jiang, Sablok, Contreras-Porcia and Ralph. Seagrasses are marine ecosystem engineers that are currently declining in abundance at an alarming rate due to both natural and anthropogenic disturbances in ecological niches. Despite reports on the morphological and physiological adaptations of seagrasses to extreme environments, little is known of the molecular mechanisms underlying photo-acclimation, and/or tolerance in these marine plants. This study applies the two-dimensional isoelectric focusing (2D-IEF) proteomics approach to identify photo-acclimation/tolerance proteins in the marine seagrass Zostera muelleri. For this, Z. muelleri was exposed for 10 days in laboratory mesocosms to saturating (control, 200 µmol photons m−2 s−1), super-saturating (SSL, 600 µmol photons m−2 s−1), and limited light (LL, 20 µmol photons m−2 s−1) irradiance conditions. Using LC-MS/MS analysis, 93 and 40 protein spots were differentially regulated under SSL and LL conditions, respectively, when compared to the control. In contrast to the LL condition, Z. muelleri robustly tolerated super-saturation light than control conditions, evidenced by their higher relative maximum electron transport rate and minimum saturating irradiance values. Proteomic analyses revealed up-regulation and/or appearances of proteins belonging to the Calvin-Benson and Krebs cycle, glycolysis, the glycine cleavage system of photorespiration, and the antioxidant system. These proteins, together with those from the inter-connected glutamate-proline-GABA pathway, shaped Z. muelleri photosynthesis andgrowth under SSL conditions. In contrast, the LL condition negatively impacted the metabolic activities of Z. muelleri by down-regulating key metabolic enzymes for photosynthesis and the metabolism of carbohydrates and amino acids, which is consistent with the observation with lower photosynthetic performance under LL condition. This study provides novel insights into th...

Kusumo, F, Silitonga, AS, Masjuki, HH, Ong, HC, Siswantoro, J & Mahlia, TMI 2017, 'Optimization of transesterification process for Ceiba pentandra oil: A comparative study between kernel-based extreme learning machine and artificial neural networks', Energy, vol. 134, pp. 24-34.
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© 2017 Elsevier Ltd In this study, kernel-based extreme learning machine (K-ELM) and artificial neural network (ANN) models were developed in order to predict the conditions of an alkaline-catalysed transesterification process. The reliability of these models was assessed and compared based on the coefficient of determination (R2), root mean squared error (RSME), mean average percent error (MAPE) and relative percent deviation (RPD). The K-ELM model had higher R2 (0.991) and lower RSME, MAPE and RPD (0.688, 0.388 and 0.380) compared to the ANN model (0.984, 0.913, 0.640 and 0.634). Based on these results, the K-ELM model is a more reliable prediction model and it was integrated with ant colony optimization (ACO) in order to achieve the highest Ceiba pentandra methyl ester yield. The optimum molar ratio of methanol to oil, KOH catalyst weight, reaction temperature, reaction time and agitation speed predicted by the K-ELM model integrated with ACO was 10:1, 1 %wt, 60 °C, 108 min and 1100 rpm, respectively. The Ceiba pentandra methyl ester yield attained under these optimum conditions was 99.80%. This novel integrated model provides insight on the effect of parameters investigated on the methyl ester yield, which may be useful for industries involved in biodiesel production.

Kusumo, F, Silitonga, AS, Ong, HC, Masjuki, HH & Mahlia, TMI 2017, 'A comparative study of ultrasound and infrared transesterification of Sterculia foetida oil for biodiesel production', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 39, no. 13, pp. 1339-1346.
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© 2017 Taylor & Francis. In this study, biodiesel production using ultrasound and infrared techniques is introduced. The ultrasound and infrared techniques are more efficient for biodiesel production since they improve the mass transfer between the immiscible reactants, increase chemical reactions, and decrease the reaction time and energy consumption. The effect of the reaction time on the acid value of the esterified Sterculia feotida oil is also investigated and it is found that the acid value is 0.76 and 0.85 mg KOH/g for the ultrasound and infrared technique, respectively, at a reaction time of 60 min. In addition, it is found that the biodiesel yield obtained from the ultrasound technique is higher (99.41%) compared to the infrared technique (98.55%) at a reaction time of 60 min. The KOH catalyst is analyzed for both of these techniques and it is found that the ultrasound technique gives faster absorbed reaction compared to the infrared technique. Hence, it can be concluded that the ultrasound and infrared transesterification techniques are promising techniques for biodiesel production.

Lang, L, Pocquet, M, Ni, B-J, Yuan, Z & Spérandio, M 2017, 'Comparison of different two-pathway models for describing the combined effect of DO and nitrite on the nitrous oxide production by ammonia-oxidizing bacteria', Water Science and Technology, vol. 75, no. 3, pp. 491-500.
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The aim of this work is to compare the capability of two recently proposed two-pathway models for predicting nitrous oxide (N2O) production by ammonia-oxidizing bacteria (AOB) for varying ranges of dissolved oxygen (DO) and nitrite. The first model includes the electron carriers whereas the second model is based on direct coupling of electron donors and acceptors. Simulations are confronted to extensive sets of experiments (43 batches) from different studies with three different microbial systems. Despite their different mathematical structures, both models could well and similarly describe the combined effect of DO and nitrite on N2O production rate and emission factor. The model-predicted contributions for nitrifier denitrification pathway and hydroxylamine pathway also matched well with the available isotopic measurements. Based on sensitivity analysis, calibration procedures are described and discussed for facilitating the future use of those models.

Larkum, AWD, Davey, PA, Kuo, J, Ralph, PJ & Raven, JA 2017, 'Carbon-concentrating mechanisms in seagrasses', Journal of Experimental Botany, vol. 68, no. 14, pp. 3773-3784.
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Seagrasses are unique angiosperms that carry out growth and reproduction submerged in seawater. They occur in at least three families of the Alismatales. All have chloroplasts mainly in the cells of the epidermis. Living in seawater, the supply of inorganic carbon (Ci) to the chloroplasts is diffusion limited, especially under unstirred conditions. Therefore, the supply of CO2 and bicarbonate across the diffusive boundary layer on the outer side of the epidermis is often a limiting factor. Here we discuss the evidence for mechanisms that enhance the uptake of Ci into the epidermal cells. Since bicarbonate is plentiful in seawater, a bicarbonate pump might be expected; however, the evidence for such a pump is not strongly supported. There is evidence for a carbonic anhydrase outside the outer plasmalemma. This, together with evidence for an outward proton pump, suggests the possibility that local acidification leads to enhanced concentrations of CO2 adjacent to the outer tangential epidermal walls, which enhances the uptake of CO2, and this could be followed by a carbon-concentrating mechanism (CCM) in the cytoplasm and/or chloroplasts. The lines of evidence for such an epidermal CCM are discussed, including evidence for special 'transfer cells' in some but not all seagrass leaves in the tangential inner walls of the epidermal cells. It is concluded that seagrasses have a CCM but that the case for concentration of CO2 at the site of Rubisco carboxylation is not proven.

Larsson, ME, Ajani, PA, Rubio, AM, Guise, K, McPherson, RG, Brett, SJ, Davies, KP & Doblin, MA 2017, 'Long-term perspective on the relationship between phytoplankton and nutrient concentrations in a southeastern Australian estuary', Marine Pollution Bulletin, vol. 114, no. 1, pp. 227-238.
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© 2016 Elsevier Ltd Sixteen years (1997–2013) of physicochemical, nutrient and phytoplankton biomass (Chlorophyll-a (Chl-a)) data and a decade (2003-2013) of phytoplankton composition and abundance data were analyzed to assess how the algal community in a temperate southeastern Australian estuary has responded to decreased chronic point source nitrogen loading following effluent treatment upgrade works in 2003. Nitrogen concentrations were significantly lower (P < 0.05) following enhanced effluent treatment and Chl-a levels decreased (P < 0.05) during the warmer months. Temperature and nutrient concentrations significantly influenced temporal changes of Chl-a (explaining 55% of variability), while salinity, temperature, pH and nutrient concentrations influenced phytoplankton abundance and composition (25% explained). Harmful Algal Bloom (HAB) dynamics differed between sites likely influenced by physical attributes of the estuary. This study demonstrates that enhanced effluent treatment can significantly decrease chronic point source nitrogen loading and that Chl-a concentrations can be lowered during the warmer months when the risk of blooms and HABs is greatest.

Le, TM, Fatahi, B, Khabbaz, H & Sun, W 2017, 'Numerical optimization applying trust-region reflective least squares algorithm with constraints to optimize the non-linear creep parameters of soft soil', Applied Mathematical Modelling, vol. 41, pp. 236-256.
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© 2016 Determination of the creep model parameters is a challenging task particularly when a non-linear elastic visco-plastic (EVP) model is adopted, mainly due to the limited test duration as well as the assumption of the reference time. Therefore, this paper presents an innovative numerical solution to find the EVP model parameters applying the trust-region reflective least square optimization algorithm. The developed approach involves several available laboratory consolidation test results in the optimization procedure with the adopted commencing time to creep as a unit of time. In this paper, the laboratory results of Ottawa clay were employed to demonstrate the limitation of the recent method to obtain model parameters. Furthermore, the developed method is verified against Skå-Edeby clay in the laboratory conditions. The EVP model parameters are obtained by applying the developed method to the available laboratory consolidation results of clay samples. The analysis results of vertical strains and excess pore water pressures demonstrate that the developed method can be a feasible tool to estimate the settlement properties of clays.

Lee, E-J, An, AK, Hadi, P, Lee, S, Woo, YC & Shon, HK 2017, 'Advanced multi-nozzle electrospun functionalized titanium dioxide/polyvinylidene fluoride-co-hexafluoropropylene (TiO2/PVDF-HFP) composite membranes for direct contact membrane distillation', Journal of Membrane Science, vol. 524, pp. 712-720.
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The unique capabilities of electrospinning technology are being increasingly utilized in the fabrication of hydrophobic membranes to improve the membrane distillation (MD) process in recent years. In this study, hydrophobic titanium dioxide (TiO2) nanoparticles functionalized by fluorosilane were incorporated into electrospun membranes using single, coaxial, and dual nozzles to develop novel membrane architectures for improved physico-chemical properties for MD. By incorporating fluorosilane coated TiO2 into the PVDF-HFP solution during the membrane synthesis and using an advanced multi-nozzle to form various hierarchical membrane structures tuned the size and structure of the nanofibers and made them vastly superior for the application in MD. The single and coaxial nozzle membranes showed contact angles close to 150° and the dual-nozzle membrane assembled bead-on-string fibers achieved superhydrophobicity (i.e., contact angle of 153.4°). To test the functionalized titanium dioxide/polyvinylidene fluoride-co-hexafluoropropylene (TiO2/PVDF-HFP) composite membranes for MD performance, the membranes were subjected to long-term direct contact MD for about two days to monitor their water vapor flux and selectivity. Compared to commercial PVDF membranes, all electrospun F-TiO2/ PVDF-HFP membrane achieved higher water vapor flux of 40 L m−2 h−1 (60 °C feed and 20 °C permeate) with a brine (7.0 wt% NaCl) as the feed solution and also exhibited anti-wetting property while maintaining high water flux compared to the membrane without TiO2 incorporation.

Lee, E-J, Deka, BJ, Guo, J, Woo, YC, Shon, HK & An, AK 2017, 'Engineering the Re-Entrant Hierarchy and Surface Energy of PDMS-PVDF Membrane for Membrane Distillation Using a Facile and Benign Microsphere Coating', Environmental Science & Technology, vol. 51, no. 17, pp. 10117-10126.
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© 2017 American Chemical Society. To consolidate the position of membrane distillation (MD) as an emerging membrane technology that meets global water challenges, it is crucial to develop membranes with ideal material properties. This study reports a facile approach for a polyvinylidene fluoride (PVDF) membrane surface modification that is achieved through the coating of the surface with poly(dimethylsiloxane) (PDMS) polymeric microspheres to lower the membrane surface energy. The hierarchical surface of the microspheres was built without any assistance of a nano/microcomposite by combining the rapid evaporation of tetrahydrofuran (THF) and the phase separation from condensed water vapor. The fabricated membrane exhibited superhydrophobicity - a high contact angle of 156.9° and a low contact-angle hysteresis of 11.3° - and a high wetting resistance to seawater containing sodium dodecyl sulfate (SDS). Compared with the control PVDF-hexafluoropropylene (HFP) single-layer nanofiber membrane, the proposed fabricated membrane with the polymeric microsphere layer showed a smaller pore size and higher liquid entry pressure (LEP). When it was tested for the direct-contact MD (DCMD) in terms of the desalination of seawater (3.5% of NaCl) containing SDS of a progressively increased concentration, the fabricated membrane showed stable desalination and partial wetting for the 0.1 and 0.2 mM SDS, respectively.

Lee, J, Jeong, S, Ye, Y, Chen, V, Vigneswaran, S, Leiknes, T & Liu, Z 2017, 'Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength', Separation and Purification Technology, vol. 176, pp. 323-334.
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� 2016 Elsevier B.V. The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 7, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling intera ction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

Lee, J, Vigneswaran, S, Zhang, Y, Raj Reddy, RSP & Liu, Z 2017, 'Effective natural organic matter removal in pond water by carbon nanotube membrane with flocculation/adsorption', Water Supply, vol. 17, no. 4, pp. 1080-1087.
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A carbon nanotube (CNT) ultrafiltration (UF) membrane was applied to natural organic matter (NOM) removal in pond water treatment. The source water was pretreated by flocculation and/or adsorption prior to the UF process to alleviate permeate flux decline and improve NOM removal efficiency. The performance of a commercial polyethersulfone (PES) UF membrane was compared to evaluate that of the CNT membrane. The CNT membrane outperformed the PES-UF membrane. The permeate flux, total organic carbon and humic acid (HA) removal rate of the CNT membrane was observed to be 230 LMH/bar, 60%, and 80% when 30 mg/L poly aluminium chloride (PACI) flocculation was applied. This highlights that the permeate flux was three times higher with slightly higher rejection efficiency than the PES-UF membrane. In particular, severe permeate flux decline was completely overcome by the CNT membrane with 30 mg/L PACI coagulation. For powder activated carbon (PAC) adsorption, even though there was a severe permeate flux decline in the CNT membrane, almost complete HA removal (98%) was achieved when 0.5 g/L PAC adsorption was coupled. Based on the superior performance of the CNT membrane with pretreatment, the CNT membrane is suggested to be a robust system for a high concentration of organic matter pond water treatment without membrane flux decline.

Lee, S, Shon, HK & Hong, S 2017, 'Dewatering of activated sludge by forward osmosis (FO) with ultrasound for fouling control', Desalination, vol. 421, pp. 79-88.
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© 2017 Elsevier B.V. Ultrasound was used to improve a forward osmosis (FO) sludge dewatering process for the control of fouling by deposited sludge flocs. FO was able to concentrate activated sludge from a real-scale wastewater reclamation plant. However, the flux decline indicated a severe fouling phenomenon. To mitigate this FO fouling, ultrasound radiation using a novel cell configuration was applied. However, the application of continuous radiation unexpectedly resulted in more severe fouling. Fluorescence excitation-emission matrix (FEEM) spectroscopy showed that longer ultrasound radiation applications caused high organic release from sludge flocs. Confocal scanning laser microscopy (CLSM) clearly identified a thicker organic fouling layer on the FO membrane surface. Ultrasound cleaning was optimized for radiation length and improved by the integration of flushing. Specifically, the combination of ultrasound and flushing caused a flux loss recovery of 70% or more. This work demonstrated the possibility of ultrasound cleaning as a fouling control method for FO sludge dewatering applications.

Li, H, Zhou, B, Tian, Z, Guo, J, Ngo, HH, Lu, C, Han, Y & Song, Y 2017, 'Improving anoxic/aerobic nutrients removal by the enhanced biological phosphorus removal-sulfur autotrophic denitrification (EBPR-SAD) system when treating low C/N ratio municipal wastewater', DESALINATION AND WATER TREATMENT, vol. 95, pp. 247-261.
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© 2017 Desalination Publications. All rights reserved. A novel nutrients removal system integrating enhanced biological phosphorus removal (EBPR) and sulfur autotrophic denitrification (SAD) was developed to upgrade the Shenyang Degremont Anoxic Oxic process (SDAO). In this system, the EBPR process was mainly employed to utilize organic carbon for denitrification and phosphorus removal; the SAD process was used to remove nitrate, which was not removed in the EBPR process because of a low C/N ratio. The results showed that the EBPR-SAD effluent COD, TN, NH4+–N and TP were 24.6, 1.21, 1.09 and 0.24 mg/L, respectively. Compared with those of the original system, the removal efficiencies of TN and TP increased to 95.8% and 86.9%. It was demonstrated that the EBPR-SAD system could achieve nearly complete nutrients removal from low C/N ratio municipal wastewater. Cluster analysis and principal coordinate analysis showed that bacterial community structures were significantly different between SDAO, EBPR and SAD processes, indicating that bacterial community structures were affected by the type of wastewater biotreatment system. Taxonomic analysis showed that the nine most abundant phyla in the SDAO and EBPR-SAD system accounted for 87.0%–90.7% of the total effective sequences. Redundancy analysis was used to reveal the relationship between the abundance of bacterial phyla and environmental parameters in the SDAO and EBPR-SAD system.

Li, J, Jiang, B, Liu, Y, Qiu, C, Hu, J, Qian, G, Guo, W & Ngo, HH 2017, 'Preparation and adsorption properties of magnetic chitosan composite adsorbent for Cu 2+ removal', Journal of Cleaner Production, vol. 158, pp. 51-58.
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Li, M, Wu, H, Zhang, J, Ngo, HH, Guo, W & Kong, Q 2017, 'Nitrogen removal and nitrous oxide emission in surface flow constructed wetlands for treating sewage treatment plant effluent: Effect of C/N ratios', Bioresource Technology, vol. 240, pp. 157-164.
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In order to design treatment wetlands with maximal nitrogen removal and minimal nitrous oxide (N2O) emission, the effect of influent C/N ratios on nitrogen removal and N2O emission in surface flow constructed wetlands (SF CWs) for sewage treatment plant effluent treatment was investigated in this study. The results showed that nitrogen removal and N2O emission in CWs were significantly affected by C/N ratio of influent. Much higher removal efficiency of NH4(+)-N (98%) and TN (90%) was obtained simultaneously in SF CWs at C/N ratios of 12:1, and low N2O emission (8.2mg/m(2)/d) and the percentage of N2O-N emission in TN removal (1.44%) were also observed. These results obtained in this study would be utilized to determine how N2O fluxes respond to variations in C/N ratios and to improve the sustainability of CWs for wastewater treatment.

Li, S, Kim, Y, Chekli, L, Phuntsho, S, Shon, HK, Leiknes, T & Ghaffour, N 2017, 'Impact of reverse nutrient diffusion on membrane biofouling in fertilizer-drawn forward osmosis', Journal of Membrane Science, vol. 539, pp. 108-115.
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© 2017 Elsevier B.V. Biofouling in fertilizer-drawn forward osmosis (FDFO) for water reuse was investigated by spiking pure bacteria species Pseudomonas aeruginosa PAO1+GFP and using three different fertilizers KNO3, KCl and KH2PO4 as draw solutions. The performance of FO process for treating synthetic wastewater was assessed and their influence on the membrane fouling and in particular biofouling was evaluated relative to the type of different fertilizers used and their rates of reverse diffusion. FO performances using KNO3 as draw solute exhibited severer flux decline (63%) than when using KCl (45%) and KH2PO4 (30%). Membrane autopsy indicated that the mass of organic foulants and biomass on fouled membrane surface using KNO3 as draw solute (947.5 mg/m2 biopolymers, 72 µm biofilm thickness and 53.3 mg/m2 adenosine triphosphate) were significantly higher than that using KCl (450 mg/m2 biopolymers, 33 µm biofilm thickness and 28.2 mg/m2 ATP) and KH2PO4 (440 mg/m2 biopolymers, 35 µm biofilm thickness and 33.5 mg/m2 ATP). This higher flux decline is likely related to the higher reverse diffusion of KNO3 (19.8 g/m2/h) than KCl (5.1 g/m2/h) and KH2PO4 (3.7 g/m2/h). The reverse diffused potassium could promote the organics and bacterial adhesion on FO membrane via charge screening effect and compression of electrical double layer. Moreover, reverse diffused nitrate provided increased N:P nutrient ratio was favorable for the bacteria to grow on the feed side of the FO membrane.

Li, S, Kim, Y, Phuntsho, S, Chekli, L, Shon, HK, Leiknes, T & Ghaffour, N 2017, 'Methane production in an anaerobic osmotic membrane bioreactor using forward osmosis: Effect of reverse salt flux', Bioresource Technology, vol. 239, pp. 285-293.
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© 2017 Elsevier Ltd This study investigated the impact of reverse salt flux (RSF) on microbe community and bio-methane production in a simulated fertilizer driven FO-AnMBR system using KCl, KNO3 and KH2PO4 as draw solutes. Results showed that KH2PO4 exhibited the lowest RSF in terms of molar concentration 19.1 mM/(m2.h), while for KCl and KNO3 it was 32.2 and 120.8 mM/(m2.h), respectively. Interestingly, bio-methane production displayed an opposite order with KH2PO4, followed by KCl and KNO3. Pyrosequencing results revealed the presence of different bacterial communities among the tested fertilizers. Bacterial community of sludge exposed to KH2PO4 was very similar to that of DI-water and KCl. However, results with KNO3 were different since the denitrifying bacteria were found to have a higher percentage than the sludge with other fertilizers. This study demonstrated that RSF has a negative effect on bio-methane production, probably by influencing the sludge bacterial community via environment modification.

Li, X, Mo, Y, Li, J, Guo, W & Ngo, HH 2017, 'In-situ monitoring techniques for membrane fouling and local filtration characteristics in hollow fiber membrane processes: A critical review', Journal of Membrane Science, vol. 528, pp. 187-200.
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Lim, S, Park, MJ, Phuntsho, S, Tijing, LD, Nisola, GM, Shim, W-G, Chung, W-J & Shon, HK 2017, 'Dual-layered nanocomposite substrate membrane based on polysulfone/graphene oxide for mitigating internal concentration polarization in forward osmosis', Polymer, vol. 110, pp. 36-48.
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© 2016 Elsevier Ltd A novel thin-film composite (TFC) forward osmosis (FO) membrane with dual-layered substrate membrane was fabricated by a double-blade casting technique using different polysulfone (PSf) concentrations for top (15 wt%) and bottom (7 wt%) substrate layers. Graphene oxide (GO) was incorporated in the substrate layer, and the dual casting approach resulted in a membrane support with a highly porous bottom structure and a dense top skin layer on which the polyamide active layer was effectively formed. The dual-layered TFC PSf/GO membrane (TFC-PSfdGO) exhibited high water permeability, and ion selectivity was enhanced by the presence of well dispersed hydrophilic GO in the PSf substrate. The TFC-PSfdGO also exhibited the lowest specific reverse salt flux (Js/Jv = 0.19 g L-1) and a more favorable structural parameter (S = 130 μm) compared to GO-free membranes. Using deionized water as feed solution and 1 M NaCl as draw solution (DS), TFC-PSfdGO had Jv = 33.8 L m−2 h−1 and Js = 6.9 g−2 h−1 under AL-FS mode, and Jv = 61.5 L m−2h−1 and Js = 14.0 g−2 h−1 under AL-DS mode. The potential of TFC-PSfdGO for commercial application was further evaluated by fabricating it with a fabric backing support (denoted as TFC-PSfdGOf). Compared to TFC-PSfdGO, TFC-PSfdGOf exhibited only 14% decline in its water flux. The overall results reveal that, fabrication of TFC substrate membrane via dual-blade casting approach along with GO incorporation produced high-performance TFC FO membranes which likely reduced the internal concentration polarization effects.

Liu, T, Ma, B, Chen, X, Ni, B-J, Peng, Y & Guo, J 2017, 'Evaluation of mainstream nitrogen removal by simultaneous partial nitrification, anammox and denitrification (SNAD) process in a granule-based reactor', Chemical Engineering Journal, vol. 327, pp. 973-981.
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© 2017 Elsevier B.V. The mainstream anaerobic ammonium oxidation (anammox) has attracted extensive attention recently, particularly due to its potential of transforming current wastewater treatment plants from energy consuming to energy neutral or positive. However, the presence of biodegradable chemical oxygen demanding (COD, 20–80 mg COD L−1) in the mainstream anammox reactor stimulates the growth of heterotrophic bacteria, which would compete for oxygen with ammonia-oxidizing bacteria (AOB) and for nitrite with anammox bacteria, thus interfering with the autotrophic nitrogen removal process. In the present work, with consideration of granule size distribution, a one-dimensional model describing the mainstream simultaneous partial nitrification, anammox and denitrification (SNAD) in a granule-based reactor was established, calibrated and validated, based on the long-term experimental results. Through applying the verified model, simulation studies were conducted and the results showed that the effluent total nitrogen concentration of <5 mg N L−1 could be achieved at C/N ratio of 0.2–0.6, DO concentration of 0.2–0.4 mg L−1 and granule radius of 300–600 μm. The combined effects indicated that the SNAD process with TN removal efficiency >90% was obtained at C/N ratio and DO concentration of 0.2–1.0 and 0.2–0.4 mg O2 L−1 respectively. Finally, the various granule size distribution patterns were simulated, which confirmed that the size distribution needed to be incorporated in the model to accurately describe the granular anammox system, considering a model based on a uniform granule size does not reflect the real situations. These results provide guides to optimize the operation of mainstream granular autotrophic nitrogen removal process.

Liu, Y, Ngo, HH, Guo, W, Sun, J, Wang, D, Peng, L & Ni, B-J 2017, 'Modeling aerobic biotransformation of vinyl chloride by vinyl chloride-assimilating bacteria, methanotrophs and ethenotrophs', Journal of Hazardous Materials, vol. 332, pp. 97-103.
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© 2017 Elsevier B.V. Recent studies have investigated the potential of enhanced groundwater Vinyl Chloride (VC) remediation in the presence of methane and ethene through the interactions of VC-assimilating bacteria, methanotrophs and ethenotrophs. In this study, a mathematical model was developed to describe aerobic biotransformation of VC in the presence of methane and ethene for the first time. It examines the metabolism of VC by VC-assimilating bacteria as well as cometabolism of VC by both methanotrophs and ethenotrophs, using methane and ethene respectively, under aerobic conditions. The developed model was successfully calibrated and validated using experimental data from microcosms with different experimental conditions. The model satisfactorily describes VC, methane and ethene dynamics in all microcosms tested. Modeling results describe that methanotrophic cometabolism of ethene promotes ethenotrophic VC cometabolism, which significantly enhances aerobic VC degradation in the presence of methane and ethene. This model is expected to be a useful tool to support effective and efficient processes for groundwater VC remediation.

Liu, Y, Ngo, HH, Guo, W, Zhou, J, Peng, L, Wang, D, Chen, X, Sun, J & Ni, B-J 2017, 'Optimizing sulfur-driven mixotrophic denitrification process: System performance and nitrous oxide emission', Chemical Engineering Science, vol. 172, pp. 414-422.
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© 2017 Nitrate contamination of groundwater has been recognized as a significant environmental problem world widely. Sulfur-driven mixotrophic denitrification has been demonstrated as a promising groundwater treatment process, which though plays an important role in nitrous oxide (N2O) emissions, significantly contributing to the overall carbon footprint of the system. However, the current process optimizations only focus on nitrate removal and excess sulfate control, with the N2O emission being ignored. In this work, an integrated mathematical model was proposed to evaluate the N2O emission as well as the excess sulfate production and carbon source utilization in sulfur-driven mixotrophic denitrification process. In this model, autotrophic and heterotrophic denitrifiers use their corresponding electron donors (sulfur and organic matter, respectively) to reduce nitrate to nitrogen gas, with each modeled as three-step denitrification (NO3− to N2 via NO2− and N2O) driven by sulfur or organic matter to describe all potential N2O accumulation steps. The developed model, employing model parameters previously reported in literature, was successfully validated using N2O and sulfate data from two mixotrophic denitrification systems with different initial conditions. Modeling results revealed substantial N2O accumulation due to the relatively low autotrophic N2O reduction activity as compared to heterotrophic N2O reduction activity, explaining the observation that higher carbon source addition resulted in lower N2O accumulation in sulfur-driven mixotrophic denitrifying system. Based on the validated model, optimizations of the overall system performance were carried out. Application of the model to simulate long-term operations of sulfur-driven mixotrophic denitrification process indicates that longer sludge retention time reduces N2O emission due to better retention of active biomass. High-level total nitrogen removal with significant N2O emission mitigation, a...

Liu, Y, Pan, Y, Huang, D & Wang, Q 2017, 'Fault prognosis of filamentous sludge bulking using an enhanced multi-output gaussian processes regression', Control Engineering Practice, vol. 62, pp. 46-54.
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The activated sludge process (ASP) is widely adopted to remove pollutants in wastewater treatment plants (WWTPs). However, the occurrence of filamentous sludge bulking often compromises the stable operation of the ASP. For timely diagnosis of filamentous sludge bulking for an activated sludge process in advance, this study proposed a Multi-Output Gaussian Processes Regression (MGPR) model for multi-step prediction and presented the Vector auto-regression (VAR) to learn the MGPR modelling deviation. The resulting models and associated uncertainty levels are used to monitor the filamentous sludge bulking related parameter, sludge volume index (SVI), such that the evolution of SVI can be predicted for both one-step and multi-step ahead. This methodology was validated with SVI data collected from one full-scale WWTP. Online diagnosis and prognosis of filamentous bulking sludge with real-time SVI prediction were tested through a simulation study. The results demonstrated that the proposed methodology was capable of predicting future SVI with good accuracy, thereby providing sufficient time for filamentous sludge bulking.

Liu, Y, Zhang, Y, Zhao, Z, Ngo, HH, Guo, W, Zhou, J, Peng, L & Ni, B-J 2017, 'A modeling approach to direct interspecies electron transfer process in anaerobic transformation of ethanol to methane', Environmental Science and Pollution Research, vol. 24, no. 1, pp. 855-863.
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© 2016, Springer-Verlag Berlin Heidelberg. Recent studies have shown that direct interspecies electron transfer (DIET) plays an important part in contributing to methane production from anaerobic digestion. However, so far anaerobic digestion models that have been proposed only consider two pathways for methane production, namely, acetoclastic methanogenesis and hydrogenotrophic methanogenesis, via indirect interspecies hydrogen transfer, which lacks an effective way for incorporating DIET into this paradigm. In this work, a new mathematical model is specifically developed to describe DIET process in anaerobic digestion through introducing extracellular electron transfer as a new pathway for methane production, taking anaerobic transformation of ethanol to methane as an example. The developed model was able to successfully predict experimental data on methane dynamics under different experimental conditions, supporting the validity of the developed model. Modeling predictions clearly demonstrated that DIET plays an important role in contributing to overall methane production (up to 33 %) and conductive material (i.e., carbon cloth) addition would significantly promote DIET through increasing ethanol conversion rate and methane production rate. The model developed in this work will potentially enhance our current understanding on syntrophic metabolism via DIET.

Loganathan, P, Naidu, G & Vigneswaran, S 2017, 'Mining valuable minerals from seawater: a critical review', Environmental Science: Water Research & Technology, vol. 3, no. 1, pp. 37-53.
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Methods of extracting valuable minerals from seawater and seawater brines generated in desalination plants are critically reviewed in this paper.

Lotfi, F, Chekli, L, Phuntsho, S, Hong, S, Choi, JY & Shon, HK 2017, 'Understanding the possible underlying mechanisms for low fouling tendency of the forward osmosis and pressure assisted osmosis processes', Desalination, vol. 421, pp. 89-98.
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© 2017 Elsevier B.V. We investigated the possible underlying mechanism of the low fouling potential in the forward osmosis (FO) process during the osmotic dilution of seawater as part of the simultaneous desalination and wastewater reuse by FO and reverse osmosis hybrid system. Long-term experiments revealed an interesting water flux pattern highly dependent on the different operating parameters. The most interesting observation made was the spontaneous increase in the FO permeate flux at regular time interval during the FO operation using synthetic wastewater as feed and seawater. This sinusoidal FO flux pattern related well with the build-up of loose fouling layer and their natural peel-off from the membrane surface upon reaching certain layer thickness due to crossflow velocity shear. This flux pattern was more prominent at higher cross-flow velocity rates, lower feed water pH, for a smoother membrane surface and at lower operating pressure during pressure assisted osmosis (PAO) mode. Based on these results, membrane cleaning strategies were proposed by targeting a higher cross-flow velocity shear at a time when the permeate flux started to just increase. The approach of physical membrane cleaning was observed efficient and was able to almost fully restore the initial flux even under the PAO operation at 4 bar.

Luo, L, Duan, N, Wang, XC, Guo, W & Ngo, HH 2017, 'New thermodynamic entropy calculation based approach towards quantifying the impact of eutrophication on water environment', Science of The Total Environment, vol. 603-604, pp. 86-93.
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Luo, W, Phan, HV, Li, G, Hai, FI, Price, WE, Elimelech, M & Nghiem, LD 2017, 'An Osmotic Membrane Bioreactor–Membrane Distillation System for Simultaneous Wastewater Reuse and Seawater Desalination: Performance and Implications', Environmental Science & Technology, vol. 51, no. 24, pp. 14311-14320.
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Luo, W, Phan, HV, Xie, M, Hai, FI, Price, WE, Elimelech, M & Nghiem, LD 2017, 'Osmotic versus conventional membrane bioreactors integrated with reverse osmosis for water reuse: Biological stability, membrane fouling, and contaminant removal', Water Research, vol. 109, pp. 122-134.
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This study systematically compares the performance of osmotic membrane bioreactor - reverse osmosis (OMBR-RO) and conventional membrane bioreactor - reverse osmosis (MBR-RO) for advanced wastewater treatment and water reuse. Both systems achieved effective removal of bulk organic matter and nutrients, and almost complete removal of all 31 trace organic contaminants investigated. They both could produce high quality water suitable for recycling applications. During OMBR-RO operation, salinity build-up in the bioreactor reduced the water flux and negatively impacted the system biological treatment by altering biomass characteristics and microbial community structure. In addition, the elevated salinity also increased soluble microbial products and extracellular polymeric substances in the mixed liquor, which induced fouling of the forward osmosis (FO) membrane. Nevertheless, microbial analysis indicated that salinity stress resulted in the development of halotolerant bacteria, consequently sustaining biodegradation in the OMBR system. By contrast, biological performance was relatively stable throughout conventional MBR-RO operation. Compared to conventional MBR-RO, the FO process effectively prevented foulants from permeating into the draw solution, thereby significantly reducing fouling of the downstream RO membrane in OMBR-RO operation. Accumulation of organic matter, including humic- and protein-like substances, as well as inorganic salts in the MBR effluent resulted in severe RO membrane fouling in conventional MBR-RO operation.

Ma, B, Yang, L, Wang, Q, Yuan, Z, Wang, Y & Peng, Y 2017, 'Inactivation and adaptation of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria when exposed to free nitrous acid', Bioresource Technology, vol. 245, no. Pt A, pp. 1266-1270.
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Inactivation and adaptation of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) to free nitrous acid (FNA) was investigated. Batch test results showed that AOB and NOB were inactivated when treated with FNA. After an 85-day operating period, AOB in a continuous pre-denitrification reactor did not adapt to the FNA that was applied to treat some of the return activated sludge. In contrast, NOB did adapt to FNA. NOB activity in the seed sludge was only 11% of the original activity after FNA batch treatment, at 0.75mg HNO2-N/L. NOB activity in the pre-denitrification reactor was not affected after being exposed to this FNA level. Nitrosomonas was the dominant AOB before and after long-term FNA treatment. However, dominant NOB changed from Nitrospira to Candidatus Nitrotoga, a novel NOB genus, after long-term FNA treatment. This adaptation of NOB to FNA may be due to the shift in NOB population makeup.

Macreadie, PI, Nielsen, DA, Kelleway, JJ, Atwood, TB, Seymour, JR, Petrou, K, Connolly, RM, Thomson, ACG, Trevathan‐Tackett, SM & Ralph, PJ 2017, 'Can we manage coastal ecosystems to sequester more blue carbon?', Frontiers in Ecology and the Environment, vol. 15, no. 4, pp. 206-213.
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To promote the sequestration of blue carbon, resource managers rely on best‐management practices that have historically included protecting and restoring vegetated coastal habitats (seagrasses, tidal marshes, and mangroves), but are now beginning to incorporate catchment‐level approaches. Drawing upon knowledge from a broad range of environmental variables that influence blue carbon sequestration, including warming, carbon dioxide levels, water depth, nutrients, runoff, bioturbation, physical disturbances, and tidal exchange, we discuss three potential management strategies that hold promise for optimizing coastal blue carbon sequestration: (1) reducing anthropogenic nutrient inputs, (2) reinstating top‐down control of bioturbator populations, and (3) restoring hydrology. By means of case studies, we explore how these three strategies can minimize blue carbon losses and maximize gains. A key research priority is to more accurately quantify the impacts of these strategies on atmospheric greenhouse‐gas emissions in different settings at landscape scales.

Mahlia, TMI, Masjuki, HH, Choudhury, IA & R. Saidur, ARS 2017, 'A review on energy efficiency standards and labels: present status and implementation possibilities in malaysia', ASEAN Journal on Science and Technology for Development, vol. 18, no. 1, pp. 71-84.
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This article is a review on energy efficiency standards  and labels for household electrical appliances around the world. Through the review of other country experiences on energy efficiency standards and labels, we attempt to identify savings possibilities in Malaysian households. The implementation possibilities of standards and labels for various household electrical appliances in Malaysia are also examined. It is found that various household appliances in Malaysia offer some potential in reducing electricity consumption. Finally, it is concluded that there are many advantages for Malaysia to implement the standards and labels for household electrical appliances as soon as possible in order to reduce electricity  bills  and energy  consumption  in Malaysian  households. 

Manjunath, SV, Kumar, SM, Ngo, HH & Guo, W 2017, 'Metronidazole removal in powder-activated carbon and concrete-containing graphene adsorption systems: Estimation of kinetic, equilibrium and thermodynamic parameters and optimization of adsorption by a central composite design', Journal of Environmental Science and Health, Part A, vol. 52, no. 14, pp. 1269-1283.
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Metronidazole (MNZ) removal by two adsorbents, i.e., concrete-containing graphene (CG) and powder-activated carbon (PAC), was investigated via batch-mode experiments and the outcomes were used to analyze the kinetics, equilibrium and thermodynamics of MNZ adsorption. MNZ sorption on CG and PAC has followed the pseudo-second-order kinetic model, and the thermodynamic parameters revealed that MNZ adsorption was spontaneous on PAC and non-spontaneous on CG. Subsequently, two-parameter isotherm models, i.e., Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Elovich models, were applied to evaluate the MNZ adsorption capacity. The maximum MNZ adsorption capacities ([Formula: see text]) of PAC and CG were found to be between 25.5-32.8 mg/g and 0.41-0.002 mg/g, respectively. Subsequently, the effects of pH, temperature and adsorbent dosage on MNZ adsorption were evaluated by a central composite design (CCD) approach. The CCD experiments have pointed out the complete removal of MNZ at a much lower PAC dosage by increasing the system temperature (i.e., from 20°C to 40°C). On the other hand, a desorption experiment has shown 3.5% and 1.7% MNZ removal from the surface of PAC and CG, respectively, which was insignificant compared to the sorbed MNZ on the surface by adsorption. The overall findings indicate that PAC and CG with higher graphene content could be useful in MNZ removal from aqueous systems.

Mannan, A, Mohd Sabri, MF, Kalam, MA & Masjuki, HH 2017, 'Tribological properties of hydrogen free DLC in self-mated contacts against ZDDP-added oil', Industrial Lubrication and Tribology, vol. 69, no. 6, pp. 938-944.
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Purpose The purpose of this study is to investigate the tribological properties of tetrahedral diamond-like carbon (DLC) films in self-mated contacts in the presence of additivated and non-additivated vegetable oils. DLC films have high practical value due to low friction and low wear properties. On the other hand, vegetable oils are considered to be lubricants for future due to its resource renewability and biodegradability. Sometimes different chemical agents are added to vegetable oils to further improve its tribological properties. Thus, the tribological study of DLC films against additivated oils becomes important. Design/methodology/approach The tribology tests were conducted in a four ball tribo-meter under the boundary lubricated conditions. Findings Ta-C DLC exhibited 80 per cent lower wear rate under Zinc dialkyldithiophosphates (ZDDP)-added oil compared to that of base oil. In contrast, the friction coefficient under additivated oil was slightly higher than the base oil lubricated case. Moreover, the carbonyl band area as well as the viscosity change of ZDDP-added oil was much smaller than that of base oil. Therefore, ZDDP reduced the wear of DLC film and prevented the oxidation of base oil during tribotests. Originality/value This is the first work on the tribological properties of ta-C DLC lubricated with corn oil with and without anti-wear additives.

McElroy, DJ, Hochuli, DF, Doblin, MA, Murphy, RJ, Blackburn, RJ & Coleman, RA 2017, 'Effect of copper on multiple successional stages of a marine fouling assemblage', Biofouling, vol. 33, no. 10, pp. 904-916.
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© 2017 Informa UK Limited, trading as Taylor & Francis Group. Copper based paints are used to prevent fouling on the hulls of ships. The widely documented effect of copper on hull assemblages may be primarily due to direct effects on the invertebrates themselves or indirect effects from copper absorbed into the microbial biofilm before settlement has commenced. Artificial units of habitat were exposed to varied regimes of copper to examine (1) the photosynthetic efficiency and pigments of early-colonising biofilms, and (2) subsequent macroinvertebrate assemblage change in response to the different regimes of copper. Macroinvertebrate assemblages were found to be less sensitive to the direct effects of copper than indirect effects as delivered through biofilms that have been historically exposed to copper, with some species more tolerant than others. This raises further concern for the efficacy of copper as a universal antifoulant on the hulls of ships, which may continue to assist the invasion of copper-tolerant invertebrate species.

McKenzie, TG, Colombo, E, Fu, Q, Ashokkumar, M & Qiao, GG 2017, 'Sono‐RAFT Polymerization in Aqueous Medium', Angewandte Chemie International Edition, vol. 56, no. 40, pp. 12302-12306.
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AbstractThe ultrasonic irradiation of aqueous solution is demonstrated to be a suitable source of initiating radicals for a controlled radical polymerization when conducted in the presence of a thiocarbonylthio‐containing reversible addition–fragmentation chain transfer (RAFT) agent. This allows for a highly “green” method of externally regulated/controlled polymerization with a potentially broad scope for polymerizable monomers and/or polymer structures.

Mei, P, Pramanik, M, Young, C, Huang, Z, Hossain, MSA, Sugahara, Y & Yamauchi, Y 2017, 'Synthesis of mesostructured manganese phosphonate and its promising energy storage application', Journal of Materials Chemistry A, vol. 5, no. 44, pp. 23259-23266.
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Mesostructured manganese phosphonate (MnP) with a uniform nanorod morphology has been prepared through an easy surfactant-mediated procedure.

Monirul, IM, Kalam, MA, Masjuki, HH, Zulkifli, NWM, Shahir, SA, Mosarof, MH & Ruhul, AM 2017, 'Influence of poly(methyl acrylate) additive on cold flow properties of coconut biodiesel blends and exhaust gas emissions', Renewable Energy, vol. 101, pp. 702-712.
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Biodiesel comprises fatty acid esters and is used as an alternative fuel for diesel engines. However, biodiesel has poor cold flow properties (i.e., CP, CFPP and PP) than mineral diesel fuel. This study aims to reduce the PP, CFPP and CP of coconut biodiesel (CB) blends using poly(methyl acrylate) (PMA) additives and investigate their effects on single-cylinder four-stroke diesel engine performance and exhaust gas emission. DSC and TGA were used to observe crystal behavior and thermal stability of the biodiesel fuel blends. Engine performance and emission were analyzed by Dynomax-2000 software and gas analyzer, respectively. Results showed that 20% of CB blended with diesel and 0.03 wt% of PMA showed significant improvement in the PP, CFPP and CP. Other properties of B20 with additives met the requirements of ASTM D6751. The BSFC of B20 with PMA was reduced by 3.247%, whereas the BTE was increased by 2.16%, compared with those of B20. Burning B20 with PMA increased the NO emission by 2.15%, whereas HC, CO and smoke emissions were 19.81%, 13.35% and 3.93% lower than those of B20, respectively. Therefore, CB20 blend with 0.03 wt% PMA can be used as an alternative fuel in cold regions without compromising fuel quality.

Monirul, IM, Masjuki, HH, Kalam, MA, Zulkifli, NWM & Shancita, I 2017, 'Influence of polymethyl acrylate additive on the formation of particulate matter and NOX emission of a biodiesel–diesel-fueled engine', Environmental Science and Pollution Research, vol. 24, no. 22, pp. 18479-18493.
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Naidu, G, Jeong, S, Choi, Y & Vigneswaran, S 2017, 'Membrane distillation for wastewater reverse osmosis concentrate treatment with water reuse potential', Journal of Membrane Science, vol. 524, pp. 565-575.
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© 2016 Elsevier B.V. Membrane distillation (MD) was evaluated as a treatment option of wastewater reverse osmosis concentrate (WWROC) discharged from wastewater reclamation plants (WRPs). A direct contact MD (DCMD), at obtaining 85% water recovery of WWROC showed only 13–15% flux decline and produced good quality permeate (10–15 µS/cm, 99% ion rejection) at moderate feed temperature of 55 °C. Prevalent calcium carbonate (CaCO 3 ) deposition on the MD membrane occurred in treating WWROC at elevated concentrations. The combination of low salinity and loose CaCO 3 adhesion on the membrane did not significantly contribute to DCMD flux decline. Meanwhile, high organic content in WWROC (58–60 mg/L) resulted in a significant membrane hydrophobicity reduction (70% lower water contact angle than virgin membrane) attributed to low molecular weight organic adhesion onto the MD membrane. Granular activated carbon (GAC) pretreatment helped in reducing organic contents of WWROC by 46–50%, and adsorbed a range of hydrophobic and hydrophilic micropollutants. This ensured high quality water production by MD (micropollutants-free) and enhanced its reuse potential. The MD concentrated WWROC was suitable for selective ion precipitation, promising a near zero liquid discharge in WRPs.

Naidu, G, Jeong, S, Johir, MAH, Fane, AG, Kandasamy, J & Vigneswaran, S 2017, 'Rubidium extraction from seawater brine by an integrated membrane distillation-selective sorption system', Water Research, vol. 123, pp. 321-331.
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© 2017 Elsevier Ltd The ultimate goal of seawater reverse osmosis (SWRO) brine management is to achieve minimal liquid discharge while recovering valuable resources. The suitability of an integrated system of membrane distillation (MD) with sorption for the recovery of rubidium (Rb+) and simultaneous SWRO brine volume reduction has been evaluated for the first time. Polymer encapsulated potassium copper hexacyanoferrate (KCuFC(PAN)) sorbent exhibited a good selectivity for Rb+ sorption with 10–15% increment at 55 °C (Langmuir Qmax = 125.11 ± 0.20 mg/g) compared to at 25 °C (Langmuir Qmax = 108.71 ± 0.20 mg/g). The integrated MD-KCuFC(PAN) system with periodic membrane cleaning, enabled concentration of SWRO brine to a volume concentration factor (VCF) of 2.9 (65% water recovery). A stable MD permeate flux was achieved with good quality permeate (conductivity of 15–20 μS/cm). Repeated cycles of MD-KCuFC(PAN) sorption with SWRO brine enabled the extraction of 2.26 mg Rb+ from 12 L of brine (equivalent to 1.9 kg of Rb/day, or 0.7 tonne/yr from a plant producing 10,000 m3/day brine). KCuFC(PAN) showed a high regeneration and reuse capacity. NH4Cl air stripping followed by resorcinol formaldehyde (RF) resin filtration enabled to recover Rb+ from the desorbed solution.

Naidu, G, Shim, WG, Jeong, S, Choi, Y, Ghaffour, N & Vigneswaran, S 2017, 'Transport phenomena and fouling in vacuum enhanced direct contact membrane distillation: Experimental and modelling', Separation and Purification Technology, vol. 172, pp. 285-295.
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© 2016 Elsevier B.V. The application of vacuum to direct contact membrane distillation (vacuum enhanced direct contact membrane distillation, V-DCMD) removed condensable gasses and reduced partial pressure in the membrane pores, achieving 37.6% higher flux than DCMD at the same feed temperature. Transfer mechanism and temperature distribution profile in V-DCMD were studied. The empirical flux decline (EFD) model represented fouling profiles of V-DCMD. In a continuous V-DCMD operation with moderate temperature (55 °C) and permeate pressure (300 mbar) for treating wastewater ROC, a flux of 16.0 ± 0.3 L/m 2  h and high quality distillate were achieved with water flushing, showing the suitability of V-DCMD for ROC treatment.

Nam, E, Wong, EHH, Tan, S, Fu, Q, Blencowe, A & Qiao, GG 2017, 'Antifogging Surface Facilitated by Nanoscale Coatings with Controllable Hydrophobicity and Cross‐Linking Density', Macromolecular Materials and Engineering, vol. 302, no. 1, pp. 1600199-1600199.
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Antifogging and frost-resistant coatings can be used in a wide range of applications and enable high light transmission through substrates even under changes in environmental conditions. In this study, surface confined and cross-linked antifogging thin films are fabricated on glass slides via catalyst induced cross-linking (CIC), which has been recently introduced as an easy and efficient cross-linking methodology. Four different poly(ethylene glycol) (PEG)-based polymers with different hydrophilicity are synthesized and used to prepare films via CIC. Films prepared from the most hydrophilic PEG-based polymers display the best antifogging performances when exposed to a temperature change from −20 to 22 °C. Furthermore, several parameters including cross-linking density, surface roughness, hydrophobicity, and exposure time are also evaluated in terms of film transparency. Through these measurements, it is determined that, more loosely cross-linked films retain antifogging ability for longer time periods due to higher film swellability as compared to, more highly cross-linked films. This study signifies the crucial role of the film cross-linking density and hydrophilicity on the antifogging function. (Figure presented.).

Nghiem, LD, Koch, K, Bolzonella, D & Drewes, JE 2017, 'Full scale co-digestion of wastewater sludge and food waste: Bottlenecks and possibilities', Renewable and Sustainable Energy Reviews, vol. 72, pp. 354-362.
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© 2017 Wastewater treatment plants in many countries use anaerobic digesters for biosolids management and biogas generation. Opportunities exist to utilise the spare capacity of these digesters to co-digest food waste and sludge for energy recovery and a range of other economic and environmental benefits. This paper provides a critical perspective for full-scale implementation of co-digestion of food waste and wastewater sludge. Data compiled from full-scale facilities and the peer-reviewed literature revealed several key bottlenecks hindering full-scale implementation of co-digestion. Indeed, co-digestion applications remain concentrated mostly in countries or regions with favourable energy and waste management policies. Not all environmental benefits from waste diversion and resource recovery can be readily monetarised into revenue to support co-digestion projects. Our field surveys also revealed the important issue of inert impurities in food waste with significant implication to the planning, design, and operation of food waste processing and co-digestion plants. Other pertinent issues include regulatory uncertainty regarding gate fee, the lack of viable options for biogas utilisation, food waste collection and processing, impacts of co-digestion on biosolids reuse and downstream biogas utilisation, and lack of design and operation experience. Effort to address these bottlenecks and promote co-digestion requires a multi-disciplinary approach.

Nguyen, DD, Chang, SW, Cha, JH, Jeong, SY, Yoon, YS, Lee, SJ, Tran, MC & Ngo, HH 2017, 'Dry semi-continuous anaerobic digestion of food waste in the mesophilic and thermophilic modes: New aspects of sustainable management and energy recovery in South Korea', Energy Conversion and Management, vol. 135, pp. 445-452.
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© 2016 Elsevier Ltd In this study, parallel, bench-scale, mesophilic and thermophilic, dry, semi-continuous anaerobic digestion (DScAD) of Korea food waste (FW, containing 22% total solids (TS) and 20% volatile solids (VS)) was investigated thoroughly under varying operational conditions, including hydraulic retention times (HRTs) and organic loading rates (OLRs). The aim was to evaluate the start-up, stability, overall removal efficiency, and inhibitory effects of toxic compounds on process performance over a long-term operation lasting 100 days. The results from both digesters indicate that the simultaneous reduction of VS and the production of gas improved as the HRT decreased or the OLR increased. The highest average rates of VS reduction (79.67%) and biogas production (162.14 m 3 biogas/ton of FW, 61.89% CH 4 ), at an OLR of 8.62 ± 0.34 kg VS/m 3 day (25 days of HRT), were achieved under thermophilic DScAD. In addition, the average rates of reduction of VS and the production of biogas in thermophilic DScAD were higher by 6.88% and 16.4%, respectively, than were those in mesophilic DScAD. The inhibitory effects of ammonia, H 2 S, and volatile fatty acids (VFAs) on methane production was not clear from either of the digesters, although, apparently, their concentrations did fluctuate. This fluctuation could be attributed to the self-adaptation of the microbial well. However, digestion that was more stable and faster was observed under thermophilic conditions compared with that under mesophilic conditions. Based on our results, the optimum operational parameters to improve FW treatment and achieve higher energy yields could be determined, expanding the application of DScAD in treating organic wastes.

Nguyen, DD, Yeop, JS, Choi, J, Kim, S, Chang, SW, Jeon, B-H, Guo, W & Ngo, HH 2017, 'A new approach for concurrently improving performance of South Korean food waste valorization and renewable energy recovery via dry anaerobic digestion under mesophilic and thermophilic conditions', Waste Management, vol. 66, pp. 161-168.
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Dry semicontinuous anaerobic digestion (AD) of South Korean food waste (FW) under four solid loading rates (SLRs) (2.30-9.21kg total solids (TS)/m(3)day) and at a fixed TS content was compared between two digesters, one each under mesophilic and thermophilic conditions. Biogas production and organic matter reduction in both digesters followed similar trends, increasing with rising SLR. Inhibitor (intermediate products of the anaerobic fermentation process) effects on the digesters' performance were not observed under the studied conditions. In all cases tested, the digesters' best performance was achieved at the SLR of 9.21kg TS/m(3)day, with 74.02% and 80.98% reduction of volatile solids (VS), 0.87 and 0.90m(3) biogas/kg VSremoved, and 0.65 (65% CH4) and 0.73 (60.02% CH4) m(3) biogas/kg VSfed, under mesophilic and thermophilic conditions, respectively. Thermophilic dry AD is recommended for FW treatment in South Korea because it is more efficient and has higher energy recovery potential when compared to mesophilic dry AD.

Nguyen, DD, Yoon, YS, Bui, XT, Kim, SS, Chang, SW, Guo, W & Ngo, HH 2017, 'Influences of operational parameters on phosphorus removal in batch and continuous electrocoagulation process performance', Environmental Science and Pollution Research, vol. 24, no. 32, pp. 25441-25451.
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© 2017, Springer-Verlag GmbH Germany. Performance of an electrocoagulation (EC) process in batch and continuous operating modes was thoroughly investigated and evaluated for enhancing wastewater phosphorus removal under various operating conditions, individually or combined with initial phosphorus concentration, wastewater conductivity, current density, and electrolysis times. The results revealed excellent phosphorus removal (72.7–100%) for both processes within 3–6 min of electrolysis, with relatively low energy requirements, i.e., less than 0.5 kWh/m 3 for treated wastewater. However, the removal efficiency of phosphorus in the continuous EC operation mode was better than that in batch mode within the scope of the study. Additionally, the rate and efficiency of phosphorus removal strongly depended on operational parameters, including wastewater conductivity, initial phosphorus concentration, current density, and electrolysis time. Based on experimental data, statistical model verification of the response surface methodology (RSM) (multiple factor optimization) was also established to provide further insights and accurately describe the interactive relationship between the process variables, thus optimizing the EC process performance. The EC process using iron electrodes is promising for improving wastewater phosphorus removal efficiency, and RSM can be a sustainable tool for predicting the performance of the EC process and explaining the influence of the process variables.

Nguyen, DD, Yoon, YS, Nguyen, ND, Bach, QV, Bui, XT, Chang, SW, Le, HS, Guo, W & Ngo, HH 2017, 'Enhanced efficiency for better wastewater sludge hydrolysis conversion through ultrasonic hydrolytic pretreatment', Journal of the Taiwan Institute of Chemical Engineers, vol. 71, pp. 244-252.
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© 2016 Taiwan Institute of Chemical Engineers.The major requirements for accelerating the process of anaerobic digestion and energy production are breaking the structure of waste activated sludge (WAS), and transforming it into a soluble form suitable for biodegradation. This work investigated and analysed a novel bench-scale ultrasonic system for WAS disruption and hydrolysis using ultrasonic homogenization. Different commercial sonoreactors were used at low frequencies under a variety of operating conditions (intensity, density, power, sonication time, and total suspended solids) to evaluate the effects of the equipment on sludge hydrolysis and to generate new insights into the empirical models and mechanisms applicable to the real-world processing of wastewater sludge. A relationship was established between the operating parameters and the experimental data. Results indicated an increase in sonication time or ultrasonic intensity correlated with improved sludge hydrolysis rates, sludge temperature, and reduction rate of volatile solids (33.51%). It also emerged that ultrasonication could effectively accelerate WAS hydrolysis to achieve disintegration within 5-10 min, depending on the ultrasonic intensity. This study also determined multiple alternative parameters to increase the efficiency of sludge treatment and organic matter reduction, and establish the practicality of applying ultrasonics to wastewater sludge pretreatment.

Nguyen, L, Fatahi, B & Khabbaz, H 2017, 'Development of a Constitutive Model to Predict the Behavior of Cement-Treated Clay during Cementation Degradation: C3 Model', International Journal of Geomechanics, vol. 17, no. 7, pp. 04017010-04017010.
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© 2017 American Society of Civil Engineers. Many researchers have indicated how cementation allows treated soft clays to sustain a higher yield mean effective stress at the same void ratio as its reconstituted state, and thus, the strength of clay treated with cement increases because the cement and clay particles bond together. However, the void ratio of cement-treated clay decreases significantly in isotropic consolidation and triaxial conditions when subjected to a high mean effective stress, particularly beyond the initial yield stress. Laboratory experiments have shown that the cementation of clay gradually diminishes as the mean effective stress increases as a result of the degradation of cementation bonds. Thus, the failure envelope of cement-treated clay gradually merges with the reconstituted clay-cement mixture at high mean effective stresses. Furthermore, the shear strength of cement-treated clay is influenced by the shear degradation induced by shear deformation. In this study, by combining the mean effective stress and shear degradation, a constitutive model, referred to as the C3 model, based on the critical state framework, was developed to simulate the behavior of cement-treated clay. The proposed model includes a modified mean effective stress, a nonlinear failure envelope, a nonassociated plastic potential function, and a general stress-strain relationship to simulate the prepeak and postpeak deviatoric stress states, including the softening behavior of cement-treated clay. In this study, triaxial tests (drained and undrained) were conducted on Ballina clay treated with 10 and 12% cement and Kaolin clay treated with 5 and 10% cement, and the results are reported and discussed. The proposed model was evaluated by comparing its predictions with the triaxial test results reported on the cement-treated Ballina clay and Kaolin clay. The proposed constitutive model gave reliable predictions that agreed with the experimental results and captu...

Nguyen, T-T, Bui, X-T, Luu, V-P, Nguyen, P-D, Guo, W & Ngo, H-H 2017, 'Removal of antibiotics in sponge membrane bioreactors treating hospital wastewater: Comparison between hollow fiber and flat sheet membrane systems', Bioresource Technology, vol. 240, pp. 42-49.
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© 2017 Elsevier Ltd Hollow fiber (HF) and flat sheet (FS) Sponge MBRs were operated at 10–20 LMH flux treating hospital wastewater. Simultaneous nitrification denitrification (SND) occurred considerably with TN removal rate of 0.011–0.020 mg TN mg VSS−1 d−1. Furthermore, there was a remarkable removal of antibiotics in both Sponge MBRs, namely Norfloxacin (93–99% (FS); 62–86% (HF)), Ofloxacin (73–93% (FS); 68–93% (HF)), Ciprofloxacin (76–93% (FS); 54–70% (HF)), Tetracycline (approximately 100% for both FS and HF) and Trimethoprim (60–97% (FS); 47–93% (HF). Whereas there was a quite high removal efficiency of Erythromycin in Sponge MBRs, with 67–78% (FS) and 22–48% (HF). Moreover, a slightly higher removal of antibiotics in FS than in HF achieved, with the removal rate being of 0.67–32.40 and 0.44–30.42 µg mg VSS−1 d−1, respectively. In addition, a significant reduction of membrane fouling of 2–50 times was achieved in HF-Sponge MBR for the flux range.

Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removal of strontium from aqueous solutions and synthetic seawater using resorcinol formaldehyde polycondensate resin', Desalination, vol. 420, pp. 283-291.
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© 2017 Elsevier B.V. Strontium (Sr) is a valuable metal found in abundance in seawater. However, its recovery from seawater has received little attention despite its many industrial applications. Batch and column adsorption experiments were conducted on the removal of Sr by resorcinol formaldehyde (RF) resin in the presence of co-existing cations at pH 7.5–8.5, where maximum adsorption was found. Batch adsorption capacities of cations followed the decreasing order of Sr > Ca > Mg > K, the order being the same as that of reduction of negative zeta potential. The adsorption data for Sr, Ca and Mg satisfactorily fitted to the Langmuir adsorption model with maximum adsorption capacities of 2.28, 1.25 and 1.15 meq/g, respectively. Selectivity coefficients for Sr with respect to other metals showed that Sr was selectively adsorbed on RF. Column adsorption data for Sr only solution fitted well to the Thomas model. Sr adsorption capacity in the presence of seawater concentrations of Ca, Mg, K and Na was reduced in both batch and column experiments with highest effect from Ca and Mg. However, if Ca and Mg are removed prior to RF adsorption process by precipitation, the negative effect of these ions on Sr removal can be significantly reduced.

Nurhadi, M, Chandren, S, Yuan, LS, Ho, CS, Indra Mahlia, TM & Nur, H 2017, 'Titania-Loaded Coal Char as Catalyst in Oxidation of Styrene with Aqueous Hydrogen Peroxide', International Journal of Chemical Reactor Engineering, vol. 15, no. 1, pp. 45-55.
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AbstractTitania-loaded coal char catalyst was successfully prepared. The preparation steps involved pyrolysis of low rank coal at different temperatures and durations, sulfonation, impregnation of titanium(IV) isopropoxide, and then heating at 110 °C. It is found that the coal chars’ surfaces were rough after sulfonation and impregnation, while large pore volume, high surface area and carbon composition were observed at low pyrolysis temperature for short duration. These properties contributed to high selectivity towards benzaldehyde (> 90 %) at 600 °C (0.5–2 h)) in styrene oxidation using aqueous hydrogen peroxide as the oxidant.

Pathak, N, Chekli, L, Wang, J, Kim, Y, Phuntsho, S, Li, S, Ghaffour, N, Leiknes, T & Shon, H 2017, 'Performance of a novel baffled osmotic membrane bioreactor-microfiltration hybrid system under continuous operation for simultaneous nutrient removal and mitigation of brine discharge', Bioresource Technology, vol. 240, pp. 50-58.
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© 2017 Elsevier Ltd The present study investigated the performance of an integrated osmotic and microfiltration membrane bioreactor system for wastewater treatment employing baffles in the reactor. Thus, this reactor design enables both aerobic and anoxic processes in an attempt to reduce the process footprint and energy costs associated with continuous aeration. The process performance was evaluated in terms of water flux, salinity build up in the bioreactor, organic and nutrient removal and microbial activity using synthetic reverse osmosis (RO) brine as draw solution (DS). The incorporation of MF membrane was effective in maintaining a reasonable salinity level (612–1434 mg/L) in the reactor which resulted in a much lower flux decline (i.e. 11.48–6.98 LMH) as compared to previous studies. The stable operation of the osmotic membrane bioreactor–forward osmosis (OMBR-FO) process resulted in an effective removal of both organic matter (97.84%) and nutrient (phosphate 87.36% and total nitrogen 94.28%), respectively.

Peng, L, Kassotaki, E, Liu, Y, Sun, J, Dai, X, Pijuan, M, Rodriguez-Roda, I, Buttiglieri, G & Ni, B-J 2017, 'Modelling cometabolic biotransformation of sulfamethoxazole by an enriched ammonia oxidizing bacteria culture', Chemical Engineering Science, vol. 173, pp. 465-473.
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© 2017 Elsevier Ltd Antibiotics such as sulfamethoxazole (SFX) are environmentally hazardous after being released into the aquatic environment and challenges remain in the development of engineered prevention strategies. In this work, a mathematical model was developed to describe and evaluate cometabolic biotransformation of SFX and its transformation products (TPs) in an enriched ammonia oxidizing bacteria (AOB) culture. The growth-linked cometabolic biodegradation by AOB, non-growth transformation by AOB and non-growth transformation by heterotrophs were considered in the model framework. The production of major TPs comprising 4-Nitro-SFX, Desamino-SFX and N4-Acetyl-SFX was also specifically modelled. The validity of the model was demonstrated through testing against literature reported data from extensive batch tests, as well as from long-term experiments in a partial nitritation sequencing batch reactor (SBR) and in a combined SBR + membrane aerated biofilm reactor performing nitrification/denitrification. Modelling results revealed that the removal efficiency of SFX increased with the increase of influent ammonium concentration, whereas the influent organic matter, hydraulic retention time and solid retention time exerted a limited effect on SFX biodegradation with the removal efficiencies varying in a narrow range. The variation of influent SFX concentration had no impact on SFX removal efficiency. The established model framework enables interpretation of a range of experimental observations on SFX biodegradation and helps to identify the optimal conditions for efficient removal.

Peng, L, Liu, Y, Sun, J, Wang, D, Dai, X & Ni, B-J 2017, 'Enhancing immobilization of arsenic in groundwater: A model-based evaluation', Journal of Cleaner Production, vol. 166, pp. 449-457.
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© 2017 Elsevier Ltd The mobilization of arsenic (As) in aquatic environment (groundwater) can cause severe environmental and healthy issues. To develop remediation strategies, we proposed a comprehensive mathematical model to describe the As removal in a arsenite (As (III)) oxidizing and ferrous iron (Fe (II)) oxidizing denitrifying granular biofilm system. In the model framework, the growth-linked microbial oxidation of As (III) and Fe (II) was coupled to chemolithotrophic denitrification of one-step reduction of nitrate to nitrogen gas. Meanwhile, the precipitation of ferric iron (Fe (III)) and adsorption of arsenate (As (V)) onto the biogenic Fe (III) (hydr)oxides were also considered. The model was calibrated by comparing the model predictions against experimental data from batch experiments. The validity of the model was further demonstrated through testing against long-term experimental results from five independent bioreactors with different reactor configurations and operational conditions. Modeling results revealed that the granule size would exert a limited impact on arsenic and iron removal. Nevertheless, their removal efficiencies increased rapidly with the increase of hydraulic retention time (HRT) from 1 h to 12 h, but became independent of HRT as it further increased. The established model framework enables interpretation of a range of experimental observations on As and Fe removal and helps to identify the optimal conditions for enhanced arsenic remediation.

Peng, L, Sun, J, Liu, Y, Dai, X & Ni, B-J 2017, 'Nitrous Oxide Production in a Granule-based Partial Nitritation Reactor: A Model-based Evaluation', Scientific Reports, vol. 7, no. 1, pp. 1-9.
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AbstractSustainable wastewater treatment has been attracting increasing attentions over the past decades. However, the production of nitrous oxide (N2O), a potent GHG, from the energy-efficient granule-based autotrophic nitrogen removal is largely unknown. This study applied a previously established N2O model, which incorporated two N2O production pathways by ammonia-oxidizing bacteria (AOB) (AOB denitrification and the hydroxylamine (NH2OH) oxidation). The two-pathway model was used to describe N2O production from a granule-based partial nitritation (PN) reactor and provide insights into the N2O distribution inside granules. The model was evaluated by comparing simulation results with N2O monitoring profiles as well as isotopic measurement data from the PN reactor. The model demonstrated its good predictive ability against N2O dynamics and provided useful information about the shift of N2O production pathways inside granules for the first time. The simulation results indicated that the increase of oxygen concentration and granule size would significantly enhance N2O production. The results further revealed a linear relationship between N2O production and ammonia oxidation rate (AOR) (R2 = 0.99) under the conditions of varying oxygen levels and granule diameters, suggesting that bulk oxygen and granule size may exert an indirect effect on N2O production by causing a change in AOR.

Petrou, K, Ralph, PJ & Nielsen, DA 2017, 'A novel mechanism for host-mediated photoprotection in endosymbiotic foraminifera', The ISME Journal, vol. 11, no. 2, pp. 453-462.
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Abstract Light underpins the health and function of coral reef ecosystems, where symbiotic partnerships with photosynthetic algae constitute the life support system of the reef. Decades of research have given us detailed knowledge of the photoprotective capacity of phototrophic organisms, yet little is known about the role of the host in providing photoprotection in symbiotic systems. Here we show that the intracellular symbionts within the large photosymbiotic foraminifera Marginopora vertebralis exhibit phototactic behaviour, and that the phototactic movement of the symbionts is accomplished by the host, through rapid actin-mediated relocation of the symbionts deeper into the cavities within the calcium carbonate test. Using a photosynthetic inhibitor, we identified that the infochemical signalling for host regulation is photosynthetically derived, highlighting the presence of an intimate communication between the symbiont and the host. Our results emphasise the central importance of the host in photosymbiotic photoprotection via a new mechanism in foraminifera that can serve as a platform for exploring host–symbiont communication in other photosymbiotic organisms.

Pham, VN, Turner, B, Huang, J & Kelly, R 2017, 'Long-term strength of soil-cement columns in coastal areas', Soils and Foundations, vol. 57, no. 4, pp. 645-654.
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Phan, TN, Van Truong, TT, Ha, NB, Nguyen, PD, Bui, XT, Dang, BT, Doan, VT, Park, J, Guo, W & Ngo, HH 2017, 'High rate nitrogen removal by ANAMMOX internal circulation reactor (IC) for old landfill leachate treatment', Bioresource Technology, vol. 234, pp. 281-288.
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© 2017 Elsevier Ltd This study aimed to evaluate the performance of a high rate nitrogen removal lab-scale ANAMMOX reactor, namely Internal Circulation (IC) reactor, for old landfill leachate treatment. The reactor was operated with pre-treated leachate from a pilot Partial Nitritation Reactor (PNR) using a high nitrogen loading rate ranging from 2 to 10 kg N m−3 d−1. High rate removal of nitrogen (9.52 ± 1.11 kg N m−3 d−1) was observed at an influent nitrogen concentration of 1500 mg N L−1. The specific ANAMMOX activity was found to be 0.598 ± 0.026 gN2-N gVSS−1 d−1. Analysis of ANAMMOX granules suggested that 0.5–1.0 mm size granular sludge was the dominant group. The results of DNA analysis revealed that Candidatus Kueneniastuttgartiensis was the dominant species (37.45%) in the IC reactor, whereas other species like uncultured Bacteroidetes bacterium only constituted 5.37% in the system, but they were still responsible for removing recalcitrant organic matter.

Phuntsho, S, Kim, JE, Hong, S, Ghaffour, N, Leiknes, T, Choi, JY & Shon, HK 2017, 'A closed-loop forward osmosis-nanofiltration hybrid system: Understanding process implications through full-scale simulation', Desalination, vol. 421, pp. 169-178.
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© 2016 Elsevier B.V. This study presents simulation of a closed-loop forward osmosis (FO)-nanofiltration (NF) hybrid system using fertiliser draw solution (DS) based on thermodynamic mass balance in a full-scale system neglecting the non-idealities such as finite membrane area that may exist in a real process. The simulation shows that the DS input parameters such as initial concentrations and its flow rates cannot be arbitrarily selected for a plant with defined volume output. For a fixed FO-NF plant capacity and feed concentration, the required initial DS flow rate varies inversely with the initial DS concentration or vice-versa. The net DS mass flow rate, a parameter constant for a fixed plant capacity but that increases linearly with the plant capacity and feed concentration, is the most important operational parameter of a closed-loop system. Increasing either of them or both increases the mass flow rate to the system directly affecting the final concentration of the diluted DS with direct energy implications to the NF process. Besides, the initial DS concentration and flow rates are also limited by the optimum recovery rates at which NF process can be operated which otherwise also have direct implications to the NF energy. This simulation also presents quantitative analysis of the reverse diffusion of fertiliser nutrients towards feed brine and the gradual accumulation of feed solutes within the closed system.

Plattner, J, Naidu, G, Wintgens, T, Vigneswaran, S & Kazner, C 2017, 'Fluoride removal from groundwater using direct contact membrane distillation (DCMD) and vacuum enhanced DCMD (VEDCMD)', Separation and Purification Technology, vol. 180, pp. 125-132.
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© 2017 Elsevier B.V. Groundwater resources are under growing pressures in water scarce countries. Membrane distillation (MD) is an interesting option for drinking water production from groundwater with elevated salinity and fluoride (F) contamination. A direct contact MD (DCMD) at a moderate feed temperature of 55 °C was able to concentrate a synthetic solution representing F contaminated groundwater. An average initial flux of 13.3 L/m2/h was achieved at 75% water recovery, resulting in only 15–17% flux decline, while producing high quality permeate (96–99% F rejection). Membrane autopsy showed presence of Ca, Na, S and Mg on the used membrane. Particularly, 51–53% F precipitation was estimated in line with the saturation index (SI) model. The used MD membrane with groundwater showed only 10–12% reduction in membrane hydrophobicity, which was largely recovered with simple cleaning. Meanwhile, synthetic groundwater solution spiked with humic substances resulted in brownish deposition on MD membrane, reducing the membrane hydrophobicity significantly by 37–40%. Additionally, DCMD operation with vacuum at the permeate side (vacuum enhanced DCMD; VEDCMD) was beneficial in increasing the permeate flux by 42%. Continuous VEDCMD operation with intermediate membrane cleaning showed positive results in treating F contained groundwater while producing good quality permeate at 67% water recovery.

Qian, J, Wang, L, Wu, Y, Bond, PL, Zhang, Y, Chang, X, Deng, B, Wei, L, Li, Q & Wang, Q 2017, 'Free sulfurous acid (FSA) inhibition of biological thiosulfate reduction (BTR) in the sulfur cycle-driven wastewater treatment process', Chemosphere, vol. 176, pp. 212-220.
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A sulfur cycle-based bioprocess for co-treatment of wet flue gas desulfurization (WFGD) wastes with freshwater sewage has been developed. In this process the removal of organic carbon is mainly associated with biological sulfate or sulfite reduction. Thiosulfate is a major intermediate during biological sulfate/sulfite reduction, and its reduction to sulfide is the rate-limiting step. In this study, the impacts of saline sulfite (the ionized form: HSO3- + SO32-) and free sulfurous acid (FSA, the unionized form: H2SO3) sourced from WGFD wastes on the biological thiosulfate reduction (BTR) activities were thoroughly investigated. The BTR activity and sulfate/sulfite-reducing bacteria (SRB) populations in the thiosulfate-reducing up-flow anaerobic sludge bed (UASB) reactor decreased when the FSA was added to the UASB influent. Batch experiment results confirmed that FSA, instead of saline sulfite, was the true inhibitor of BTR. And BTR activities dropped by 50% as the FSA concentrations were increased from 8.0 × 10-8 to 2.0 × 10-4 mg H2SO3-S/L. From an engineering perspective, the findings of this study provide some hints on how to ensure effective thiosulfate accumulation in biological sulfate/sulfite reduction for the subsequent denitrification/denitritation. Such manipulation would result in higher nitrogen removal rates in this co-treatment process of WFGD wastes with municipal sewage.

Qian, J, Wei, L, Wu, Y, Wang, Q, Fu, X, Zhang, X, Chang, X, Wang, L & Pei, X 2017, 'A comparative study on denitrifying sludge granulation with different electron donors: Sulfide, thiosulfate and organics', Chemosphere, vol. 186, pp. 322-330.
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A comparative study on denitrifying sludge granulation with different electron donors (sulfide, thiosulfate and organics) was carried out. Longer time was spent on sulfide-denitrifying granular sludge (DGS) cultivation (88 days) than thiosulfate- and organics-DGS cultivations (57 days). All the three DGS were characterized in terms of particle size distribution, sludge settling ability (indicated by sludge volume index and settling velocity), permeability (indicated by fractal dimension) and extracellular polymeric substances (EPS, including polysaccharide and protein) secretion. Sludge productions in the three DGS-reactors were also monitored. The key functional microorganisms in three granular reactors were revealed via high through-put pyrosequencing analysis. Batch tests were performed to measure the denitrification activities of each DGS, including both denitratation (NO3- → NO2-) and denitritation (NO2- → N2). We found that thiosulfate-driven denitrifying sludge granulation (TDDSG) should be the most efficient and compact technology for effective BNR in municipal wastewater treatment. The findings of this study suggests the TDDSG could further increase the nitrogen removal potential in an enhanced sulfur cycle-driven bioprocess for co-treatment of wet flue gas desulfurization wastes with fresh sewage depending on three short-cut biological reactions, including: 1) short-cut biological sulfur reduction (SO42-/SO32- → S2O32-); 2) thiosulfate-driven denitritation (S2O32- + NO2- → SO42- + N2↑); and 3) nitritation (NH4+ + O2 → NO2-).

Qian, J, Zhou, J, Wang, L, Wei, L, Li, Q, Wang, D & Wang, Q 2017, 'Direct Cr (VI) bio-reduction with organics as electron donor by anaerobic sludge', Chemical Engineering Journal, vol. 309, pp. 330-338.
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Industrial activities produce lots of Cr (VI)-containing wastewater. This study presented a detailed work on direct Cr (VI) bio-reduction (i.e. Cr (VI) is reduced with organics as electron donor directly) by anaerobic sludge through both batch and long-term experiments. Effects of pH and initial Cr (VI) concentrations on direct Cr (VI) bio-reduction activity were evaluated. The highest direct Cr (VI) bio-reduction rate was achieved at pH 8.0 at 104 mg Cr (VI)/g MLVSS/d (MLVSS: mixed liquor volatile suspended solids), corresponding to the highest protein release (124 mg/g MLVSS) and cell viability (71%). In contrast, the direct Cr (VI) bio-reduction rates were 46, 70 and 82 mg Cr (VI)/g MLVSS/d, respectively, at pH 6.0, 7.0 and 9.0. Also, the direct Cr (VI) bio-reduction activity decreased by 74% when initial Cr (VI) concentration increased from 10 mg/L to 50 mg/L. The contribution of chemical adsorption to Cr (VI) removal was found to be negligible, whereas biosorption played a role in Cr (VI) removal although its role was insignificant. Indirect Cr (VI) bio-reduction (i.e. Cr (VI) is chemically reduced by sulfide produced from biological sulfate reduction) rate (990 mg Cr (VI)/g MLVSS/d) was faster than that (210 mg Cr (VI)/g MLVSS/d) of direct Cr (VI) bio-reduction, indicating that indirect Cr (VI) bio-reduction would dominate the Cr (VI) bio-reduction pathway if both Cr (VI) and sulfate were present. The direct Cr (VI) bio-reduction was then successfully demonstrated in an up-flow anaerobic sludge bed (UASB) reactor, where the Cr (VI) was completely removed with a Cr (VI) removal rate of 1.0 mg Cr (VI)/L/h. 454 pyrosequencing results revealed that direct Cr (VI) bio-reduction related genera were Desulfovibrio, Ochrobactrum and Anaerovorax.

Rahman, M, Rasul, M & Hassan, N 2017, 'Study on the Tribological Characteristics of Australian Native First Generation and Second Generation Biodiesel Fuel', Energies, vol. 10, no. 1, pp. 55-55.
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Biodiesels are a renewable energy source, and they have the potential to be used as alternatives to diesel fuel. The aim of this study is to investigate the wear and friction characteristics of Australian native first generation and second generation biodiesels using a four-ball tribo tester. The biodiesel was produced through a two-step transesterification process and characterized according to the American Society for Testing and Materials (ASTM) standards. The tribological experiment was carried out at a constant 1800 rpm and different loads and temperatures. In addition, the surface morphology of the ball was tested by scanning electron microscope (SEM)/energy dispersive X-ray spectroscopy (EDX) analysis. The test results indicated that biodiesel fuels have a lower coefficient of frictions (COF) and lower wear scar diameter (WSD) up to 83.50% and 41.28%, respectively, compared to conventional diesel fuel. The worn surface area results showed that biodiesel fuel has a minimum percentage of C and O, except Fe, compared to diesel. In addition, the worn surface area for diesel was found (2.20%-27.92%) to be higher than biodiesel. The findings of this study indicated that both first and second generation biodiesel fuels have better tribological performance than diesel fuel, and between the biodiesel fuels, macadamia biodiesel showed better lubrication performance.

Rahman, MM, Rasul, MG, Hassan, NMS, Azad, AK & Uddin, MN 2017, 'Effect of small proportion of butanol additive on the performance, emission, and combustion of Australian native first- and second-generation biodiesel in a diesel engine', Environmental Science and Pollution Research, vol. 24, no. 28, pp. 22402-22413.
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This paper aims to investigate the effect of the addition of 5% alcohol (butanol) with biodiesel-diesel blends on the performance, emissions, and combustion of a naturally aspirated four stroke multi-cylinder diesel engine at different engine speeds (1200 to 2400 rpm) under full load conditions. Three types of local Australian biodiesel, namely macadamia biodiesel (MB), rice bran biodiesel (RB), and waste cooking oil biodiesel (WCB), were used for this study, and the data was compared with results for conventional diesel fuel (B0). Performance results showed that the addition of butanol with diesel-biodiesel blends slightly lowers the engine efficiency. The emission study revealed that the addition of butanol additive with diesel-biodiesel blends lowers the exhaust gas temperature (EGT), carbon monoxide (CO), nitrogen oxide (NOx), and particulate matter (PM) emissions whereas it increases hydrocarbon (HC) emissions compared to B0. The combustion results indicated that in-cylinder pressure (CP) for additive added fuel is higher (0.45-1.49%), while heat release rate (HRR) was lower (2.60-9.10%) than for B0. Also, additive added fuel lowers the ignition delay (ID) by 23-30% than for B0. Finally, it can be recommended that the addition of 5% butanol with Australian biodiesel-diesel blends can significantly lower the NOx and PM emissions.

Rashedul, HK, Kalam, MA, Masjuki, HH, Teoh, YH, How, HG, Monirul, IM & Imdadul, HK 2017, 'Attempts to minimize nitrogen oxide emission from diesel engine by using antioxidant-treated diesel-biodiesel blend', Environmental Science and Pollution Research, vol. 24, no. 10, pp. 9305-9313.
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Ren, J, Tijing, LD & Shon, HK 2017, '“Robbing behavior” and re-immobilization of nanoscale zero-valent iron (nZVI) onto electrospun polymeric nanofiber mats for trichloroethylene (TCE) remediation', Separation and Purification Technology, vol. 189, pp. 375-381.
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© 2017 Elsevier B.V. In this study, we first revealed a “robbing behavior” during the immobilization of nZVI particles onto an electrospun polyacrylic acid (PAA)-polyvinyl alcohol (PVA) nanofiber mat. The robbing behavior can significantly reduce the number of nZVI particles immobilized onto the mat and hence weaken the performance of mitigating contaminated water. To minimize the undesirable effect of robbing behavior, we developed a dipping method that enables exposure of enough free Fe (II) as electron acceptors to the Fe (II)-complexed PAA-PVA mat for the subsequent reduction. The result indicates that the mat with dipping can immobilize more than 1.7 times the weight percentage of nZVI particles for the mat without dipping. Moreover, the dipping method can also re-immobilize or enrich nZVI particles on the mat that has already partially immobilized nZVI particles. The nZVI-immobilized mat dipped once into the FeSO4 solution with a very little concentration (0.32 g/L) had an excellent performance for trichloroethylene (TCE) degradation (more than 92% TCE removed). Here, the developed dipping method shows great potential for nZVI immobilization and groundwater remediation.

Ren, J, Tijing, LD & Shon, HK 2017, 'Effect of polymer ratio on nZVI loading onto Electrospun nanofiber mat for mitigating groundwater contaminants', Advanced Materials - TechConnect Briefs 2017, vol. 2, pp. 265-268.
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Nanoscale zero-valent iron (nZVI) has been widely used for the reduction of halogenated organics and heavy metals in the groundwater. However, individual nZVI particles are mobile and prone to aggregate, thereby reducing the reaction sites exposed to contaminants. Electrospun polymer nanofiber mat is an ideal carrier to immobilize and distribute nZVI particles after its merits of high specific area, size-controllable and material-compatible properties. In this study, nZVI particles were loaded onto the polyacrylic acid (PAA)-polyvinyl alcohol (PVA) electrospun nanofiber mats with different PAA/PVA ratios. The results indicate that mat with the PAA/PVA ratio of 3:1 loaded the most nZVI particles (∼48 wt%) and had the highest removals to methylene blue at 94% and Cu (II) ions at 84% respectively. The nZVI-loaded electrospun nanofiber mat has promising application for the groundwater contaminants mitigation.

Ren, J, Woo, YC, Yao, M, Tijing, LD & Shon, HK 2017, 'Enhancement of nanoscale zero-valent iron immobilization onto electrospun polymeric nanofiber mats for groundwater remediation', Process Safety and Environmental Protection, vol. 112, no. Part B, pp. 200-208.
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© 2017 Institution of Chemical Engineers A new approach that combines nanoscale zero-valent iron (nZVI) with electrospinning technology has been put forward to avoid nZVI agglomeration and a secondary pollution. In this study, to enhance the immobilization of nZVI particles onto the polyacrylic acid (PAA)/polyvinyl alcohol (PVA) electrospun nanofiber mat, mats (M1, M2 and M3) with different PAA/PVA mass ratios (1:1, 2:1 and 3:1) were tested for the immobilization of nZVI particles and their performance of removing contaminants. The results indicate that M3 immobilized the most nZVI particles (48.4 wt% on the mat, ∼2.5 times the figure for previous study) and had the highest removals to methylene blue and Cu(II) ions at 94% and 83.6% respectively, resulting from more free carboxylic groups available on the cross-linked nanofibers as well as a higher porosity into the mat. Therefore, increasing the PAA/PVA ratio is effective to boost the performance of nZVI–PAA/PVA electrospun nanofiber mat, which has a great potential for the application of nZVI-targeted contaminants remediation.

Reyhani, A, McKenzie, TG, Ranji‐Burachaloo, H, Fu, Q & Qiao, GG 2017, 'Fenton‐RAFT Polymerization: An “On‐Demand” Chain‐Growth Method', Chemistry – A European Journal, vol. 23, no. 30, pp. 7221-7226.
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AbstractFine control over the architecture and/or microstructure of synthetic polymers is fast becoming a reality owing to the development of efficient and versatile polymerization techniques and conjugation reactions. However, the transition of these syntheses to automated, programmable, and high‐throughput operating systems is a challenging step needed to translate the vast potential of precision polymers into machine‐programmable polymers for biological and functional applications. Chain‐growth polymerizations are particularly appealing for their ability to form structurally and chemically well‐defined macromolecules through living/controlled polymerization techniques. Even using the latest polymerization technologies, the macromolecular engineering of complex functional materials often requires multi‐step syntheses and purification of intermediates, and results in sub‐optimal yields. To develop a proof‐of‐concept of a framework polymerization technique that is readily amenable to automation requires several key characteristics. In this study, a new approach is described that is believed to meet these requirements, thus opening avenues toward automated polymer synthesis.

Riayatsyah, TMI, Ong, HC, Chong, WT, Aditya, L, Hermansyah, H & Mahlia, TMI 2017, 'Life Cycle Cost and Sensitivity Analysis of Reutealis trisperma as Non-Edible Feedstock for Future Biodiesel Production', Energies, vol. 10, no. 7, pp. 877-877.
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© 2017 by the authors. The use of non-edible, second-generation feedstocks for the production of biodiesel has been an active area of research, due to its potential in replacing fossil diesel as well as its environmentally friendly qualities. Despite this, more needs to be done to remove the technical barriers associated with biodiesel production and usage, to increase its quality as well as to widen the choice of available feedstocks; so as to avoid over-dependence on limited sources. This paper assesses the feasibility of using a local plant, Reutealis trisperma, whose seeds contain a high percentage of oil of up to 51%, as one of the possible feedstocks. The techno-economic and sensitivity analysis of biodiesel production from Reutealis trisperma oil as well as implementation aspects and environmental effects of the biodiesel plant are discussed. Analysis indicates that the 50 kt Reutealis trisperma biodiesel production plant has a life cycle cost of approximately 710 million, yielding a payback period of 4.34 years. The unit cost of the biodiesel is calculated to be 0.69/L with the feedstock cost accounting for the bulk of the cost. The most important finding from this study is that the biodiesel from Reutealis trisperma oil can compete with fossil diesel, provided that appropriate policies of tax exemptions and subsidies can be put in place. To conclude, further studies on biodiesel production and its limitations are necessary before the use of biodiesel from Reutealis trisperma oil may be used as a fuel source to replace fossil diesel.

Robinson, CM, Cherukuru, N, Hardman-Mountford, NJ, Everett, JD, McLaughlin, MJ, Davies, KP, Van Dongen-Vogels, V, Ralph, PJ & Doblin, MA 2017, 'Phytoplankton absorption predicts patterns in primary productivity in Australian coastal shelf waters', Estuarine, Coastal and Shelf Science, vol. 192, pp. 1-16.
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© 2017 Elsevier Ltd The phytoplankton absorption coefficient (aPHY) has been suggested as a suitable alternate first order predictor of net primary productivity (NPP). We compiled a dataset of surface bio-optical properties and phytoplankton NPP measurements in coastal waters around Australia to examine the utility of an in-situ absorption model to estimate NPP. The magnitude of surface NPP (0.20–19.3 mmol C m−3 d−1) across sites was largely driven by phytoplankton biomass, with higher rates being attributed to the microplankton (>20 μm) size class. The phytoplankton absorption coefficient aPHY for PAR (photosynthetically active radiation; āPHY)) ranged from 0.003 to 0.073 m-1, influenced by changes in phytoplankton community composition, physiology and environmental conditions. The aPHY coefficient also reflected changes in NPP and the absorption model-derived NPP could explain 73% of the variability in measured surface NPP (n = 41; RMSE = 2.49). The absorption model was applied to two contrasting coastal locations to examine NPP dynamics: a high chlorophyll-high variation (HCHV; Port Hacking National Reference Station) and moderate chlorophyll-low variation (MCLV; Yongala National Reference Station) location in eastern Australia using the GIOP-DC satellite aPHY product. Mean daily NPP rates between 2003 and 2015 were higher at the HCHV site (1.71 ± 0.03 mmol C m−3 d−1) with the annual maximum NPP occurring during the austral winter. In contrast, the MCLV site annual NPP peak occurred during the austral wet season and had lower mean daily NPP (1.43 ± 0.03 mmol C m−3 d−1) across the time-series. An absorption-based model to estimate NPP is a promising approach for exploring the spatio-temporal dynamics in phytoplankton NPP around the Australian continental shelf.

Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Allocating Environmental Water and Impact on Basin Unemployment: Role of A Diversified Economy', Ecological Economics, vol. 136, pp. 178-188.
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© 2017 Elsevier B.V. Water diversion for environmental pu rposes threatens many agricultural communities. This paper focuses on the water-agriculture-environment nexus in the Murrumbidgee River Basin, Australia, and attempts to explain how reduced water allocation to agriculture aimed at protecting the environment in turn impacted the wider economy and the community. Predictably reduced water allocation saw declines in agriculture production and employment. Despite this, paradoxically, the basin unemployment rate declined and basin median household income increased. To understand and interpret this, we first analyze available labour, economic and hydrology data, and then develop a simple dynamic model to interpret the observed pattern of basin employment and unemployment. Data analysis revealed the likely causes behind the paradox as (a) out-migration of people from the basin, and (b) absorption of the labour force in the fast growing non-agricultural sectors of the diversified basin economy. The model simulations reinforced this interpretation. Further model simulations under alternative realities of out-migration and sectoral transformation indicated that basins embedded in faster growing national economies, and are more diversified to begin with, are likely to be more conducive to agriculture sector reform (e.g., reduced water allocation) and environmental regeneration. This is a sobering message for other regions experiencing environmental degradation due to extensive agricultural development.

Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Role of Sectoral Transformation in the Evolution of Water Management Norms in Agricultural Catchments: A Sociohydrologic Modeling Analysis', Water Resources Research, vol. 53, no. 10, pp. 8344-8365.
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AbstractThis study is focused on the water‐agriculture‐environment nexus as it played out in the Murrumbidgee River Basin, eastern Australia, and how coevolution of society and water management actually transpired. Over 100 years of agricultural development the Murrumbidgee Basin experienced a “pendulum swing” in terms of water allocation, initially exclusively for agriculture production changing over to reallocation back to the environment. In this paper, we hypothesize that in the competition for water between economic livelihood and environmental wellbeing, economic diversification was the key to swinging community sentiment in favor of environmental protection, and triggering policy action that resulted in more water allocation to the environment. To test this hypothesis, we developed a sociohydrology model to link the dynamics of the whole economy (both agriculture and industry composed of manufacturing and services) to the community's sensitivity toward the environment. Changing community sensitivity influenced how water was allocated and governed and how the agricultural sector grew relative to the industrial sector (composed of manufacturing and services sectors). In this way, we show that economic diversification played a key role in influencing the community's values and preferences with respect to the environment and economic growth. Without diversification, model simulations show that the community would not have been sufficiently sensitive and willing enough to act to restore the environment, highlighting the key role of sectoral transformation in achieving the goal of sustainable agricultural development.

Ruhul, AM, Kalam, MA, Masjuki, HH, Shahir, SA, Alabdulkarem, A, Teoh, YH, How, HG & Reham, SS 2017, 'Evaluating combustion, performance and emission characteristics of Millettia pinnata and Croton megalocarpus biodiesel blends in a diesel engine', Energy, vol. 141, pp. 2362-2376.
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Saha, N, Rahman, MS, Ahmed, MB, Zhou, JL, Ngo, HH & Guo, W 2017, 'Industrial metal pollution in water and probabilistic assessment of human health risk', Journal of Environmental Management, vol. 185, pp. 70-78.
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© 2016 Elsevier Ltd Concentration of eight heavy metals in surface and groundwater around Dhaka Export Processing Zone (DEPZ) industrial area were investigated, and the health risk posed to local children and adult residents via ingestion and dermal contact was evaluated using deterministic and probabilistic approaches. Metal concentrations (except Cu, Mn, Ni, and Zn) in Bangshi River water were above the drinking water quality guidelines, while in groundwater were less than the recommended limits. Concentration of metals in surface water decreased as a function of distance. Estimations of non-carcinogenic health risk for surface water revealed that mean hazard index (HI) values of As, Cr, Cu, and Pb for combined pathways (i.e., ingestion and dermal contact) were >1.0 for both age groups. The estimated risk mainly came from the ingestion pathway. However, the HI values for all the examined metals in groundwater were <1.0, indicating no possible human health hazard. Deterministically estimated total cancer risk (TCR) via Bangshi River water exceeded the acceptable limit of 1 × 10−4 for adult and children. Although, probabilistically estimated 95th percentile values of TCR exceeded the benchmark, mean TCR values were less than 1 × 10−4. Simulated results showed that 20.13% and 5.43% values of TCR for surface water were >1 × 10−4 for adult and children, respectively. Deterministic and probabilistic estimations of cancer risk through exposure to groundwater were well below the safety limit. Overall, the population exposed to Bangshi River water remained at carcinogenic and non-carcinogenic health threat and the risk was higher for adults. Sensitivity analysis identified exposure duration (ED) and ingestion rate (IR) of water as the most relevant variables affecting the probabilistic risk estimation model outcome.

Sahebi, S, Phuntsho, S, Tijing, L, Han, G, Han, DS, Abdel-Wahab, A & Shon, HK 2017, 'Thin-film composite membrane on a compacted woven backing fabric for pressure assisted osmosis', Desalination, vol. 406, pp. 98-108.
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© 2016 Elsevier B.V. The water flux in forward osmosis (FO) process declines substantially when the draw solution (DS) concentration reaches closer to the point of osmotic equilibrium with the feed solution (FS). Using external hydraulic pressure alongside the osmotic driving force in the pressure assisted osmosis (PAO) has been found effective in terms of enhancing water flux and even potentially diluting the DS beyond osmotic equilibrium. The net gain in water flux due to the applied pressure in the PAO process closely depends on the permeability of the FO membrane. The commercial flat sheet cellulose triacetate (CTA) FO membrane has low water permeability and hence the effective gain in water flux in the PAO process is low. In this study, a high performance thin film composite membrane was developed especially for the PAO process through casting polyethersulfone (PES) polymer solution on a compacted woven fabric mesh support followed by interfacial polymerisation for polyamide active layer. This PAO membrane possesses a water flux of 37 L m2h− 1using 0.5 M NaCl as DS and deionised water as the feed at an applied hydraulic pressure of 10 bar. Besides, the membrane was able to endure the external hydraulic pressure required for the PAO process owing to the embedded backing fabric support. While the membranes with low structural parameters are essential for higher water flux, this study shows that for PAO process, polymeric membranes with larger structural parameters may not be suitable for PAO. They generally resulted in compaction and poor mechanical strength to withstand hydraulic pressure.

Saidur, RS, Masjuki, HH, Mahlia, TMI & Nasrudin, AR 2017, 'FACTORS AFFECTING REFRIGERATOR-FREEZERS ENERGY CONSUMPTION', ASEAN Journal on Science and Technology for Development, vol. 19, no. 2, pp. 57-67.
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Two frost-free household refrigerator-freezers, one with 492 liter capacity and one with 460 liter capacity were tested in the laboratory to determine the sensitivity of several variables those influence consumption refrigerator-freezers energy consumption greatly. The effects of single variables such as room temperature, thermostat setting positions, and door openings on the energy  consumption were investigated. Using Response Surface Methodology (RSM), a mathematical model has been developed to investigate the combined effect of room temperature, thermostat setting positions, and door opening on the energy consumption of refrigerator-freezers. From the mathematical model, it has been observed that room-temperature has the highest effect on the energy consumption followed by the thermostat setting position. The door opening has lowest on the energy consumption. More detailed tests were performed under different room temperature, thermostat setting positions, and door opening conditions and presented in this paper.

Sebayang, A, Hassan, M, Ong, H, Dharma, S, Silitonga, A, Kusumo, F, Mahlia, T & Bahar, A 2017, 'Optimization of Reducing Sugar Production from Manihot glaziovii Starch Using Response Surface Methodology', Energies, vol. 10, no. 1, pp. 35-35.
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Bioethanol is known as a viable alternative fuel to solve both energy and environmental crises. This study used response surface methodology based on the Box-Behnken experimental design to obtain the optimum conditions for and quality of bioethanol production. Enzymatic hydrolysis optimization was performed with selected hydrolysis parameters, including substrate loading, stroke speed, α-amylase concentration and amyloglucosidase concentration. From the experiment, the resulting optimum conditions are 23.88% (w/v) substrate loading, 109.43 U/g α-amylase concentration, 65.44 U/mL amyloglucosidase concentration and 74.87 rpm stroke speed, which yielded 196.23 g/L reducing sugar. The fermentation process was also carried out, with a production value of 0.45 g ethanol/g reducing sugar, which is equivalent to 88.61% of ethanol yield after fermentation by using Saccharomyces cerevisiae (S. cerevisiae). The physical and chemical properties of the produced ethanol are within the specifications of the ASTM D4806 standard. The good quality of ethanol produced from this study indicates that Manihot glaziovii (M. glaziovii) has great potential as bioethanol feedstock.

Sebayang, AH, Hasan, MH, Chyuan, OH, Dharma, S, Bahar, AH, Silitonga, AS & Kusumo, F 2017, 'Enzymatic hydrolysis using ultrasound for bioethanol production from durian (durio zibethinus) seeds as potential bio fuel', Chemical Engineering Transactions, vol. 56, pp. 553-558.
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The appealing second generation bioethanol production brings a good promise to achieve a fuel production that is renewable and sustainable; this makes durian (Durio zibethinus) seed interesting to take advantage of, especially for a tropical country like Malaysia. This paper aims to produce bioethanol from durian seed by utilizing ultrasound technique in its enzymatic hydrolysis process. 9 % (w/v) pre-Treated durian seed was brought into the ultrasound-Assisted glass reactor to begin the liquefaction and saccharification processes. Bacillus licheniformis Type XII-A was employed, and ultrasound at 50% amplitude for 60 min was set for liquefaction process; while amyloglucosidase from Aspergillus niger was used, and ultrasound at 40% amplitude for 120 min was run for saccharification process. The sum of both processes in hydrolysis yielded 41.07 g/L of reducing sugar, which was immediately brought to fermentation stage. Saccharomyces cerevisiae was employed for fermentation and resulted 18.48 g/L (0.44 g ethanol/g glucose), which is equivalent to 86.27 % of theoretical ethanol yield (0.51 g ethanol/g glucose) after 84 h of fermentation at 37 °C with 150 rpm incubator shaker. The ethanol purity was improved in the next stage, distillation. Using zeolite as adsorbent, ethanol with purity of 95.7% (v/v) was produced. From the acquired results, durian seed shows a justifiably potential as a second generation bioethanol feedstock. To further improve its potential, studies of optimization using this feedstock is highly encouraged.

Sebayang, AH, Masjuki, HH, Ong, HC, Dharma, S, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Optimization of bioethanol production from sorghum grains using artificial neural networks integrated with ant colony', Industrial Crops and Products, vol. 97, pp. 146-155.
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In this study, an artificial neural networks (ANN) model is developed to investigate the relationship between bioethanol production and the operating parameters of enzymatic hydrolysis and fermentation processes. The operating parameters of the hydrolysis process which influence the reducing sugar concentration are the substrate loading, α-amylase concentration, amyloglucosidase concentration and strokes speed. The operating parameters of the fermentation process which influence the ethanol concentration are the yeast concentration, reaction temperature and agitation speed. The desirability function of the model is integrated with ant colony optimization (ACO) in order to determine the optimum operating parameters which will maximize reducing sugar and ethanol concentrations. The optimum substrate loading, α-amylase concentration, amyloglucosidase concentration and strokes speed is determined to be 20% (w/v), 109.5 U/g, 36 U/mL and 50 spm, respectively. The reducing sugar obtained at these optimum conditions is 175.94 g/L, which is close to the average value from experiments (174.29 g/L). The optimum yeast concentration, reaction temperature and agitation speed is found to be 1.3 g/L, 35.6 °C and 181 rpm, respectively. The ethanol concentration obtained from the fermentation of sorghum starch by Saccharomyces cerevisiae yeast at these optimum conditions is 82.11 g/L, which is in good agreement with the average value from experiments (81.52 g/L). Based on the results, it can be concluded that the model developed in this study model is an effective method to optimize bioethanol production, and it reduces the cost, time and effort associated with experimental techniques.

Sebayang, AH, Masjuki, HH, Ong, HC, Dharma, S, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Prediction of engine performance and emissions with Manihot glaziovii bioethanol − Gasoline blended using extreme learning machine', Fuel, vol. 210, pp. 914-921.
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Bioethanol can potentially replace gasoline because of its lower exhaust emissions. The purpose of this study was to investigate the engine performance and exhaust emissions of Manihot glaziovii bioethanol–gasoline blends at different blend ratios (5%, 10%, 15%, and 20%). Tests were performed on a single-cylinder, four-stroke spark-ignition engine with engine speed was varied from 1600 to 3400 rpm, and the properties of the Manihot glaziovii bioethanol–gasoline blends were measured and analysed. The vapour pressure increased for fuel blends with low concentrations of bioethanol due to the oxygen within the bioethanol molecules and the contribution of the flame speed which can enhance the combustion and improved the engine efficiency. In addition, the engine torque, brake power, and brake-specific fuel consumption (BSFC) were measured, as well as the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide emissions. For a fuel blend containing 20% bioethanol at an engine speed of 3200 rpm, the BSFC decreased, with maximum values of 270.7 g/kWh. The CO and HC emissions were lower for the Manihot glaziovii bioethanol–gasoline blends. In addition, an extreme learning machine (ELM) model was developed for application in the automotive and industrial sectors. This tool reduces the cost, time, and effort associated with experimental data. The blend ratio of the bioethanol–gasoline blends and the engine speed were used as the input data of the model, and the engine performance and exhaust emissions parameters were used as the output data. The coefficient of determination (R2) was within a range of 0.980–1.000, and the mean absolute percentage error was within a range of 0.411%−2.782% for all the parameters. The results indicate that the ELM model is capable of predicting the engine performance and exhaust emissions of bioethanol–gasoline fuel blends.

Semblante, GU, Hai, FI, Dionysiou, DD, Fukushi, K, Price, WE & Nghiem, LD 2017, 'Holistic sludge management through ozonation: A critical review', Journal of Environmental Management, vol. 185, pp. 79-95.
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This paper critically reviews the multidimensional benefits of ozonation in wastewater treatment plants. These benefits include sludge reduction, removal of emerging trace organic contaminants (TrOC) from wastewater and sludge, and resource recovery from sludge. Literature shows that ozonation leads to sludge solubilisation, reducing overall biomass yield. Sludge solubilisation is primarily influenced by ozone dosage, which, in turn, depends on the fraction of ozonated sludge, ozone concentration, and sludge concentration. Additionally, sludge ozonation facilitates the removal of TrOCs from wastewater. On the other hand, by inducing cell lysis, ozonation increases the chemical oxygen demand (COD) and nutrient concentration of the sludge supernatant, which deteriorates effluent quality. This issue can be resolved by implementing resource recovery. Thus far, successful retrieval of phosphorous from ozonated sludge supernatant has been performed. The recovery of phosphorous and other resources from sludge could help offset the operation cost of ozonation, and give greater incentive for wastewater treatment plants to adapt this approach.

Semblante, GU, Hai, FI, McDonald, J, Khan, SJ, Nelson, M, Lee, D-J, Price, WE & Nghiem, LD 2017, 'Fate of trace organic contaminants in oxic-settling-anoxic (OSA) process applied for biosolids reduction during wastewater treatment', Bioresource Technology, vol. 240, pp. 181-191.
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This study investigated the fate of trace organic contaminants (TrOCs) in an oxic-settling-anoxic (OSA) process consisting of a sequencing batch reactor (SBR) with external aerobic/anoxic and anoxic reactors. OSA did not negatively affect TrOC removal of the SBR. Generally, low TrOC removal was observed under anoxic and low substrate conditions, implicating the role of co-metabolism in TrOC biodegradation. Several TrOCs that were recalcitrant in the SBR (e.g., benzotriazole) were biodegraded in the external aerobic/anoxic reactor. Some hydrophobic TrOCs (e.g., triclosan) were desorbed in the anoxic reactor possibly due to loss of sorption sites through volatile solids destruction. In OSA, the sludge was discharged from the aerobic/anoxic reactor which contained lower concentration of TrOCs (e.g., triclosan and triclocarban) than that of the control aerobic digester, suggesting that OSA can also help to reduce TrOC concentration in residual biosolids.

Semblante, GU, Phan, HV, Hai, FI, Xu, Z-Q, Price, WE & Nghiem, LD 2017, 'The role of microbial diversity and composition in minimizing sludge production in the oxic-settling-anoxic process', Science of The Total Environment, vol. 607-608, pp. 558-567.
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© 2017 Elsevier B.V. The oxic-settling-anoxic (OSA) process, which involves an aerobic tank attached to oxygen- and substrate-deficient external anoxic reactors, minimizes sludge production in biological wastewater treatment. In this study, the microbial community structure of OSA was determined. Principal coordinate analysis showed that among the three operational factors, i.e., (i) redox condition, (ii) external reactor sludge retention time (SRText), and (iii) sludge interchange between aerobic and anoxic reactors, redox condition had the greatest impact on microbial diversity. Generally, reactors with lower oxidation-reduction potential had higher microbial diversity. The main aerobic sequencing batch reactor of OSA (SBROSA) that interchanged sludge with an external anoxic reactor had greater microbial diversity than SBRcontrol which did not have sludge interchange. SBROSA sustained high abundance of the slow-growing nitrifying bacteria (e.g., Nitrospirales and Nitrosomondales) and consequently exhibited reduced sludge yield. Specific groups of bacteria facilitated sludge autolysis in the external reactors. Hydrolyzing (e.g., Bacteroidetes and Chloroflexi) and fermentative (e.g., Firmicutes) bacteria, which can break down cellular matter, proliferated in both the external aerobic/anoxic and anoxic reactors. Sludge autolysis in the anoxic reactor was enhanced with the increase of predatory bacteria (e.g., order Myxobacteriales and genus Bdellovibrio) that can contribute to biomass decay. Furthermore, β- and γ-Proteobacteria were identified as the bacterial phyla that primarily underwent decay in the external reactors.

Shanmuganathan, S, Loganathan, P, Kazner, C, Johir, MAH & Vigneswaran, S 2017, 'Submerged membrane filtration adsorption hybrid system for the removal of organic micropollutants from a water reclamation plant reverse osmosis concentrate', DESALINATION, vol. 401, pp. 134-141.
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© 2016 Elsevier B.V. Reverse osmosis (RO) is a widespread water treatment process utilised in water reuse applications. However, the improper discharge of RO concentrate (ROC) containing organic micropollutants such as pharmaceuticals into the environment may cause potential health risks to non-target species and particularly those in aquatic environments. A study was conducted using a submerged membrane-filtration/granular activated carbon (GAC) adsorption hybrid system to remove organic micropollutants from a water treatment plant ROC by initially adding 10 g GAC /L of membrane reactor volume with 10% daily GAC replacement. The percentage of dissolved organic carbon removal varied from 60% to 80% over an operation lasting 10 days. Removal of organic micropollutants was almost complete for virtually all compounds. Of the 19 micropollutants tested, only two remained (the less hydrophobic DEET 27 ng/L and the hydrophilic sulfamethoxazole 35 ng/L) below 80% removal on day 1, while five of the most hydrophobic micropollutants were detectable in very small concentrations (< 5–10 ng/L) with > 89%–> 99% being removed. High percentages of micropollutants were removed probably because of their high hydrophobicity or they had positive or neutral charges and therefore they were electrostatically adsorbed to the negatively charged GAC.

Shekarchian, M, Moghavvemi, M, Zarifi, F, Moghavvemi, S, Motasemi, F & Mahlia, TMI 2017, 'Impact of infrastructural policies to reduce travel time expenditure of car users with significant reductions in energy consumption', Renewable and Sustainable Energy Reviews, vol. 77, pp. 327-335.
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© 2017 Elsevier Ltd The increasing number of vehicles and drivers have led to a marked increase in travel time expenditure (TTE), congestion, demand for fossil fuels, and adverse environmental impacts. Improving energy efficiency in the transportation sector, public awareness of the behavior of the people vis-à-vis energy efficiency, implementing policies that encourage other modes of transportation (e.g., public transit, ride-sharing, bicycles, and walking, etc.) that decrease vehicle dependency are some effective approaches that mitigate the aforementioned negative effects, which will lead to significant reductions in the total energy consumption. This article investigates the effect of governmental policies on vehicle dependency reduction and the decrease of TTE by vehicle owners, and propose a novel method to calculate the current and future TTEs by individuals. The effect of demographic variables and the region on vehicle dependency and TTE for students of three of the most populated universities in Malaysia (University of Malaya, University Putra Malaysia, and University Technology Malaysia) were investigated as well. The peoples’ expectations from individual modes of transportation such as cycling and walking were also analyzed. The results showed that all demographic factors, except nationality, affect the levels of vehicle ownership, while income levels and nationality affects TTE by personal vehicles. The results show that the average TTE can be reduced by 89% if the recommended infrastructure (e.g., increase bus routes, train routes, train services, frequencies of buses and train, and facilities for cyclists, etc.) is provided. These outcomes can assist policy makers to efficiently manage transportation budgets, and would also help people decrease vehicle usage, which will subsequently decrease their corresponding TTE and fuel consumption.

Shon, HK 2017, 'Editorial - Special issue on the 9th International Conference on Challenges in Environmental Science and Engineering (CESE-2016), 6–10 November 2016, Kaohsiung, Taiwan', DESALINATION AND WATER TREATMENT, vol. 96, pp. 1-2.
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Shon, HK, Jegatheesan, V, Shu, L & Phuntsho, S 2017, 'Challenges in Environmental Science and Engineering, CESE–2016', Process Safety and Environmental Protection, vol. 112, no. PART B, pp. 199-199.
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Shrestha, A, Naidu, G, Johir, MAH, Kandasamy, J & Vigneswaran, S 2017, 'Performance of flocculation titanium salts for seawater reverse osmosis pretreatment', DESALINATION AND WATER TREATMENT, vol. 98, pp. 92-97.
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© 2017 Desalination Publications. All rights reserved. This study evaluated the performance of titanium tetrachloride (TiCl4) and titanium sulphate (Ti(SO4)2) as coagulants to remove organic matter and solids from actual seawater. The coagulant performances were evaluated at different doses in terms of turbidity, dissolved organic carbon (DOC), humics (UV254), zeta potential and pH of the solution. The performance of Ti-salts were compared to ferric chloride (FeCl3), a commonly used coagulant. The results showed that at pH of 8.0 (closely similar to seawater pH), TiCl4 showed relatively better performance over FeCl3 and Ti(SO4)2 for the same coagulant dose of 20 mg/L. TiCl4 achieved a 70% DOC and UV254 removal. This was approximately two times higher than achieved by FeCl3 and Ti(SO4)2. Based on a floc zeta potential evaluation, the difference in performance of the coagulants were attributed to the coagulation mechanism. The coagulation mechanisms of Ti-salts were mainly charge neutralization while FeCl3was adsorption mechanism.

Silitonga, AS, Hassan, MH, Ong, HC & Kusumo, F 2017, 'Analysis of the performance, emission and combustion characteristics of a turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends using kernel-based extreme learning machine', Environmental Science and Pollution Research, vol. 24, no. 32, pp. 25383-25405.
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The purpose of this study is to investigate the performance, emission and combustion characteristics of a four-cylinder common-rail turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends. A kernel-based extreme learning machine (KELM) model is developed in this study using MATLAB software in order to predict the performance, combustion and emission characteristics of the engine. To acquire the data for training and testing the KELM model, the engine speed was selected as the input parameter, whereas the performance, exhaust emissions and combustion characteristics were chosen as the output parameters of the KELM model. The performance, emissions and combustion characteristics predicted by the KELM model were validated by comparing the predicted data with the experimental data. The results show that the coefficient of determination of the parameters is within a range of 0.9805-0.9991 for both the KELM model and the experimental data. The mean absolute percentage error is within a range of 0.1259-2.3838. This study shows that KELM modelling is a useful technique in biodiesel production since it facilitates scientists and researchers to predict the performance, exhaust emissions and combustion characteristics of internal combustion engines with high accuracy.

Silitonga, AS, Mahlia, TMI, Ong, HC, Riayatsyah, TMI, Kusumo, F, Ibrahim, H, Dharma, S & Gumilang, D 2017, 'A comparative study of biodiesel production methods for Reutealis trisperma biodiesel', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 39, no. 20, pp. 2006-2014.
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© 2017 Taylor & Francis Group, LLC. In this study, three types of biodiesel production methods are compared in order to maximize Reutealis trisperma biodiesel yields and it is found that the best method is esterification-neutralization-transesterification. The optimum methanol to oil molar ratio, catalyst concentration, reaction temperature, and reaction time are also determined from laboratory experiments and modeling using response surface methodology. There is excellent agreement between the predicted and experimental Reutealis trisperma biodiesel yields under optimum process conditions, with a value of 99.23 and 98.72%, respectively. The physicochemical properties of the Reutealis trisperma biodiesel also fulfill the fuel specifications of the ASTM D6751 standard.

Silitonga, AS, Masjuki, HH, Ong, HC, Mahlia, TMI & Kusumo, F 2017, 'Optimization of extraction of lipid from Isochrysis galbana microalgae species for biodiesel synthesis', Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 39, no. 11, pp. 1167-1175.
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© 2017 Taylor & Francis Group, LLC. Microalgae are promising alternative plant sources for biodiesel production because of the significant increase in lipid yield through heterotrophic cultivation and genetic engineering approaches. This study aims to evaluate the extraction and conversion of lipids from Isochrysis galbana. Response surface methodology (RSM) was used to optimize lipid extraction and thereby obtain high yields from the four microalgae species. The optimal lipid yields for Isochrysis galbana is 8.41 wt%. Moreover, the dominant lipid composition found from Isochrysis galbana extractions was palmitic acid (C16:0) at 22.3%. The high saturated acid of Isochrysis galbana contributed to the improved biodiesel properties because biodiesel quality is influenced by the lipid composition of microalgae species. The study employed the two-step esterification–transesterification process to convert the microalgae oil into biodiesel, glycerol, and water. The FAME content is 99.7% under the methanol to oil molar mass of 12:1, 1 wt%, 65°C, and 800 rpm. Furthermore, the main biodiesel properties, such as viscosity, higher heating value, and iodine value, were measured according to ASTM D6751 and EN 14124. Results show that microalgae oil can potentially be used as biofuel in future applications.

Song, JF, Nghiem, LD, Li, X-M & He, T 2017, 'Lithium extraction from Chinese salt-lake brines: opportunities, challenges, and future outlook', Environmental Science: Water Research & Technology, vol. 3, no. 4, pp. 593-597.
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Chinese salt-lake brine is mainly of the magnesium sulfate subtype with a high Mg/Li ratio. To extract high purity lithium chloride from Chinese brine has been a decade-long challenge. This review summarizes the state-of-the-art of lithium extraction from Chinese salt-lake brine.

Song, K, Xie, G-J, Qian, J, Bond, PL, Wang, D, Zhou, B, Liu, Y & Wang, Q 2017, 'Improved degradation of anaerobically digested sludge during post aerobic digestion using ultrasonic pretreatment', Environmental Science: Water Research & Technology, vol. 3, no. 5, pp. 857-864.
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We propose that ultrasonic pretreatment could significantly improve the degradation of anaerobically digested sludge with economic favorability in post aerobic digestion.

Sountharajah, DP, Kus, B, Kandasamy, J & Vigneswaran, S 2017, 'Quantifying the Reduction in Water Demand due to Rainwater Tank Installations at Residential Properties in Sydney', Journal of Sustainable Development of Energy, Water and Environment Systems, vol. 5, no. 2, pp. 202-218.
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© 2017, International Centre for Sustainable Development of Energy, Water and Environment Systems SDEWES. All rights reserved. This paper examines data on actual reductions in consumption of water supply due to the widespread installation of rainwater tanks at residential properties in the Sydney metropolitan area and surrounding areas connected to Sydney Water Corporation water supply mains. The water consumption was based on metered potable water usage between 2002 and 2009. The number of properties in the study database totalled 962,697 single residential dwellings. Of this a total of 52,576 or 5.5% of Sydney’s households had a rainwater tank registered with Sydney Water Corporation. The water usage consumption before and after the installation of the rainwater tank was analysed to quantify the extent to which rainwater tanks reduced mains water consumption. The average percentage of water savings by installing rainwater tanks across all 44 local government authorities was 9%. In some Sydney localities this reduction was up to 15%. On average, a household was able to save around 24 kilolitre of water annually by installing a rainwater tank even without considering other factors that affect water usage. The results were compared against socio-demographic factors using variables such as household size, educational qualifications, taxable income, rented properties, and non-English-speaking background, etc., to gain an appreciation of how these factors may have influenced the outcomes evident in the data. Among the co-relations found were that most properties within inner Sydney with a rainwater tank achieved at least a 9 to 11% additional reduction in water usage, with more than half of those local government authorities achieving more than 11%; properties with larger land area were more likely to have a rainwater tank installed; local government authorities with more people born in non-English speaking countries had lower reduction in water consumption reduction...

Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removing heavy metals using permeable pavement system with a titanate nano-fibrous adsorbent column as a post treatment', Chemosphere, vol. 168, pp. 467-473.
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© 2016 Elsevier Ltd Permeable pavement systems (PPS) are a widely-used treatment measure in sustainable stormwater management and groundwater recharge. However, PPS are not very efficient in removing heavy metals from stormwater. A pilot scale study using zeolite or basalt as bed material in PPS removed 41–72%, 67–74%, 38–43%, 61–72%, 63–73% of Cd, Cu, Ni, Pb, and Zn, respectively, from synthetic stormwater (pH 6.5; Cd, Cu, Ni, Pb, and Zn concentrations of 0.04, 0.6, 0.06, 1.0, and 2.0 mg L−1, respectively) over a period of 80 h. The total volume of stormwater that passed through the PPS was equivalent to runoff in 10 years of rainfall in Sydney, Australia. The concentrations of metals in the PPS effluent failed fresh and marine water quality trigger values recommended in the Australian and New Zealand guidelines. An addition of a post-treatment of a horizontal filter column containing a titanate nano-fibrous (TNF) material with a weight < 1% of zeolite weight and mixed in with granular activated carbon (GAC) at a GAC:TNF weight ratio of 25:1 removed 77% of Ni and 99–100% of all the other metals. The effluent easily met the required standards of marine waters and just met those concerning fresh waters. Batch adsorption data from solutions of metals mixtures fitted the Langmuir model with adsorption capacities in the following order, TNF ≫ zeolite > basalt; Pb > Cu > Cd, Ni, Zn.

Sun, J, Dai, X, Liu, Y, Peng, L & Ni, B-J 2017, 'Sulfide removal and sulfur production in a membrane aerated biofilm reactor: Model evaluation', Chemical Engineering Journal, vol. 309, pp. 454-462.
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© 2016 Elsevier B.V. Sulfide removal from wastewater is essential, in view of the toxic, malodor and corrosive property of sulfide. The oxidation of sulfide by chemolithotrophic sulfide oxidation bacteria can produce elemental sulfur, an important chemical material. A membrane aerated biofilm reactor (MABR) has been successfully implemented and demonstrated for enhanced sulfide oxidation and sulfur production, owning to its counter-diffusion design of oxygen supply. In this work, a mathematical model was developed to evaluate the sulfide oxidation and sulfur production in the MABR in the presence of residual organics in the influent. The model was calibrated and validated using the experimental data from the long-term operation of the sulfide-oxidation MABR at different operational stages. The results suggested that the developed model could satisfactorily describe sulfide oxidation, sulfur production, sulfate accumulation and organics conversion in the MABR. The modelling results indicated that with the optimal combinations of sulfide loading and oxygen pressure, over 90% of sulfide removal and over 75% of sulfur recovery could be achieved. The sulfide oxidation and sulfur production would also be affected by the biofilm area to reactor volume (A/V) ratio in the MABR, with high A/V ratio might deteriorate the sulfur production efficiency depending on the oxygen pressure applied. Further, the increase of volatile fatty acids in the wastewater would not affect the sulfide oxidation efficiency but could enhance the sulfur production efficiency by decreasing the amount of sulfur oxidized to sulfate.

Sun, J, Dai, X, Peng, L, Liu, Y, Wang, Q & Ni, B-J 2017, 'A biofilm model for assessing perchlorate reduction in a methane-based membrane biofilm reactor', Chemical Engineering Journal, vol. 327, pp. 555-563.
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© 2017 Elsevier B.V. Perchlorate (ClO4−) is recognized as an important contaminant in surface water and groundwater, which would pose health risks at very low concentrations. A methane-based membrane biofilm reactor (MBfR) has been successfully demonstrated for perchlorate reduction, which provided an alternative solution for perchlorate remediation with low cost. In this work, a multispecies biofilm model was developed to evaluate perchlorate reduction in the methane-based MBfR under different operational conditions. The model was calibrated and validated using the experimental data from the long-term operation of the MBfR at seven distinct stages. The results suggested that the developed model could satisfactorily describe perchlorate reduction and denitrification performances in the MBfR (R2 > 0.9). The modeling results provided insight into the microbial community distribution in the biofilm, with aerobic methanotrophs and perchlorate reduction bacteria being mainly located at the membrane side (∼60%) and heterotrophic bacteria being situated near the liquid side (∼50%). The model simulations indicated that over 80% of perchlorate removal efficiency could be achieved through controlling the optimal combinations of methane pressure (PCH4) and perchlorate loading (LClO4) (e.g., applying a PCH4 of 30 kPa at a LClO4 of 0.08 g Cl/m2/d). In addition, the perchlorate reduction would be inhibited by the presence of nitrate and nitrite in the MBfR, which should be appropriately controlled during the future practical application of the promising process.

Sun, W-J, Zong, F-Y, Sun, D-A, Wei, Z-F, Schanz, T & Fatahi, B 2017, 'Swelling prediction of bentonite-sand mixtures in the full range of sand content', Engineering Geology, vol. 222, pp. 146-155.
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© 2017 Elsevier B.V. The swelling prediction of bentonite–sand mixtures due to wetting is very important in evaluating the long term performance of the engineered barrier in the high level radioactive waste disposal system and the hydraulic barriers in geoenvironmental constructions. Sun et al. (2015) proposed the swelling prediction model of bentonite-sand mixtures due to full hydration, and predicted the swelling of different types of bentonite-sand mixtures, which was verified, to be consistent with the swelling test results. However, the predicted swelling results of bentonite-sand mixtures with extremely high sand content obtained by the original swelling prediction model have a large deviation from the test results. The reason is that the original model is based on an assumption that all the pores and available water are only associated with bentonite/montmorillonite fraction. However, for mixtures with extremely high sand content, the sand skeleton exists and resists the external stress from the very beginning. At the same time, the bentonite, dispersing in the sand skeleton, in contact with the pore fluid, swells freely to fully saturated state, however, still fails to fill the sand skeleton voids completely. In this research, the original swelling prediction model is extended by introducing the concept of critical filling sand content and critical contact stress. When sand content is more than the critical filling sand content, the deformation of the mixture is mainly due to the sand skeleton deformation. After the stress increases greater than the critical contact stress, the saturated bentonite fills the sand skeleton voids completely, and the swelling can still be predicted by the original swelling prediction model. In the extended model, the swelling prediction can be divided into three zones according to the two limit values of critical sand content and critical filling sand content. In different zones, the distribution ratio of the vertical stress ...

Surawski, NC, Bezantakos, S, Barmpounis, K, Dallaston, MC, Schmidt-Ott, A & Biskos, G 2017, 'A tunable high-pass filter for simple and inexpensive size-segregation of sub-10-nm nanoparticles', Scientific Reports, vol. 7, no. 1.
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AbstractRecent advanced in the fields of nanotechnology and atmospheric sciences underline the increasing need for sizing sub-10-nm aerosol particles in a simple yet efficient way. In this article, we develop, experimentally test and model the performance of a High-Pass Electrical Mobility Filter (HP-EMF) that can be used for sizing nanoparticles suspended in gaseous media. Experimental measurements of the penetration of nanoparticles having diameters down to ca 1nm through the HP-EMF are compared with predictions by an analytic, a semi-empirical and a numerical model. The results show that the HP-EMF effectively filters nanoparticles below a threshold diameter with an extremely high level of sizing performance, while it is easier to use compared to existing nanoparticle sizing techniques through design simplifications. What is more, the HP-EMF is an inexpensive and compact tool, making it an enabling technology for a variety of applications ranging from nanomaterial synthesis to distributed monitoring of atmospheric nanoparticles.

Szabó, M, Larkum, AWD, Suggett, DJ, Vass, I, Sass, L, Osmond, B, Zavafer, A, Ralph, PJ & Chow, WS 2017, 'Non-intrusive Assessment of Photosystem II and Photosystem I in Whole Coral Tissues', Frontiers in Marine Science, vol. 4, no. AUG, pp. 1-12.
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© 2017 Szabó, Larkum, Suggett, Vass, Sass, Osmond, Zavafer, Ralph and Chow. Reef building corals (phylum Cnidaria) harbor endosymbiotic dinoflagellate algae (genus Symbiodinium) that generate photosynthetic products to fuel their host's metabolism. Non-invasive techniques such as chlorophyll (Chl) fluorescence analyses of Photosystem II (PSII) have been widely used to estimate the photosynthetic performance of Symbiodinium in hospite. However, since the spatial origin of PSII chlorophyll fluorescence in coral tissues is uncertain, such signals give limited information on depth-integrated photosynthetic performance of the whole tissue. In contrast, detection of absorbance changes in the near infrared (NIR) region integrates signals from deeper tissue layers due to weak absorption and multiple scattering of NIR light. While extensively utilized in higher plants, NIR bio-optical techniques are seldom applied to corals. We have developed a non-intrusive measurement method to examine photochemistry of intact corals, based on redox kinetics of the primary electron donor in Photosystem I (P700) and chlorophyll fluorescence kinetics (Fast-Repetition Rate fluorometry, FRRf). Since the redox state of P700 depends on the operation of both PSI and PSII, important information can be obtained on the PSII-PSI intersystem electron transfer kinetics. Under moderate, sub-lethal heat stress treatments (33◦ C for~20 min), the coral Pavona decussata exhibited down-regulation of PSII electron transfer kinetics, indicated by slower rates of electron transport from QA to plastoquinone (PQ) pool, and smaller relative size of oxidized PQ with concomitant decrease of a specifically-defined P700 kinetics area, which represents the active pool of PSII. The maximum quantum efficiency of PSII (Fv /Fm ) and functional absorption cross-section of PSII (σPSII ) remained unchanged. Based on the coordinated response of P700 parameters and PSII-PSI electron transport properties, we propose...

Tan, ES, Anwar, M, Kumaran, P, Indra, TM & Yoshikawa, K 2017, 'Air assist atomization characterization of palm biodiesel through experimental investigation and CFD simulation', Biofuels, vol. 8, no. 5, pp. 571-577.
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© 2016 Informa UK Limited, trading as Taylor & Francis Group. The depletion of fossil fuel and environmental concerns have elevated biodiesel to emerge as a suitable alternative fuel to substitute diesel fuel. The study of spray formation is essential to improve the combustion systems of internal combustion engines and gas turbines. This paper aims to study the atomization characteristics of biodiesel derived from palm biodiesel through experimental test and simulation. The chemical fuel properties of biodiesel such as viscosity and density, will adversely affect the spray characteristics such as spray pattern, spray length, spray angle and Sauter Mean Diameter. The biodiesel fuels are blended with diesel in various ratios before being tested in an atomization test rig. Modelling of the atomizer are presented using computational fluid dynamics whereby comparisons are made with respect to the experimental results carried out in the atomizer test rig. There is no large discrepancy with the simulation results. The results showed that the higher content of biodiesel gives a larger droplet size and longer spray length. However, it produces smaller spray angle and spray width but with clearer vortex shape of spray pattern.

Tan, ES, Kumaran, P, Indra, TM & Yoshikawa, K 2017, 'Effect of Non-Edible Biodiesel Physical and Chemical Properties as Microturbine Fuel', Energy Procedia, vol. 142, pp. 413-418.
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The world is facing critical energy concern, in view of depleting fossil fuel reserves and increasing environment pollution. Biodiesel can potentially substitute fossil fuel, and is produced through the transesterification of vegetable oils. This paper will emphasize on the transition from first generation derived from waste cooking oil, to second generation biodiesel derived from calophyllum inophyllum, which is a non-edible plant. The objective of this paper is to optimize the performance of biodiesel blends with diesel in a 30 kW microturbine. The characterization of chemical fuel properties of distillate and biodiesel blends will be conducted to determine if it meets international standards for power generation. Temperature profiles, pressure, and flame imaging will be closely monitored to detect possible problems in operability of the combustor caused by the differences in fuel characteristics. The findings may provide useful information towards optimization of microturbine performance, considering the wide range of biodiesel feedstock that exist. The paper outcome will show the potential of non-edible biodiesel blends to be used as alternative fuel in microturbines for power generation.

Tang, J, Wang, XC, Hu, Y, Ngo, HH & Li, Y 2017, 'Dynamic membrane-assisted fermentation of food wastes for enhancing lactic acid production', Bioresource Technology, vol. 234, pp. 40-47.
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A dynamic membrane (DM) module was inserted into a fermentation reactor to separate soluble products from the fermented mixture to increase lactic acid (LA) production from food wastes under acidogenic conditions (uncontrolled pH, pH 4 and 5). With a high total suspended solid content (20-40g/L) in the fermenter, a stable DM could be maintained through regular backwashing. By effectively intercepting suspended solids and lactic acid bacteria (LAB), the fermenter was able to increase microbial activity and largely promote LA yield. Hydrolysis and acidogenesis rates increased with pH, and the highest LA yield (as high as 0.57g/g-TS) was obtained at pH 4. The microbial community analysis showed that the relative abundance of Lactobacillus increased to 96.4% at pH 4, but decreased to 43.3% at pH 5. In addition, the DM could be easily recovered by intercepting larger particles in less than 2h after each cycle of periodic backwashing.

Tang, J, Wang, XC, Hu, Y, Ngo, HH, Li, Y & Zhang, Y 2017, 'Applying fermentation liquid of food waste as carbon source to a pilot-scale anoxic/oxic-membrane bioreactor for enhancing nitrogen removal: Microbial communities and membrane fouling behaviour', Bioresource Technology, vol. 236, pp. 164-173.
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Fermentation liquid of food waste (FLFW) was applied as an external carbon source in a pilot-scale anoxic/oxic-membrane bioreactor (A/O-MBR) system to enhance nitrogen removal for treating low COD/TN ratio domestic wastewater. Results showed that, with the FLFW addition, total nitrogen removal increased from lower than 20% to 44-67% during the 150days of operation. The bacterial metabolic activities were obviously enhanced, and the significant change in microbial community structure promoted pollutants removal and favored membrane fouling mitigation. By monitoring transmembrane pressure and characterizing typical membrane foulants, such as extracellular polymeric substances (EPS), dissolved organic matter (DOM), and inorganics and biopolymers in the cake layer, it was confirmed that FLFW addition did not bring about any additional accumulation of membrane foulants, acceleration of fouling rate, or obvious irreversible membrane fouling in the whole operation period. Therefore, FLFW is a promising alternative carbon source to enhance nitrogen removal for the A/O-MBR system.

Tian, J, Wang, B, Zhao, F, Ma, X, Liu, Y, Liu, HK & Huang, Z 2017, 'Highly active Fe₃BO₆ as an anode material for sodium-ion batteries', Chemical Communications, vol. 53, no. 34, pp. 4698-4701.
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An efficient Fe₃BO₆ anode with high capacity and excellent rate capability is studied, for the first time, for sodium-ion batteries.

Tin, MMM, Anioke, G, Nakagoe, O, Tanabe, S, Kodamatani, H, Nghiem, LD & Fujioka, T 2017, 'Membrane fouling, chemical cleaning and separation performance assessment of a chlorine-resistant nanofiltration membrane for water recycling applications', Separation and Purification Technology, vol. 189, pp. 170-175.
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© 2017 Elsevier B.V. The effectiveness of hypochlorite cleaning for fouling mitigation of a prototype chlorine-resistant nanofiltration (NF) membrane was assessed for direct filtration of a secondary treated effluent. The chlorine resistance and separation performance of the prototype NF membrane were also compared to commercial NF and reverse osmosis membranes. The prototype chlorine resistant NF membrane did not show any changes in permeability and conductivity rejection after exposing a NaOCl solution for up to 5 × 10 4  ppm-h. By contrast, a considerable deterioration in rejection was observed for the other two commercial membranes. Direct filtration of a secondary treated effluent by the prototype NF membrane resulted in a progressive permeability reduction by up to 25% after 10 h of filtration. The membrane permeability was fully restored by hypochlorite cleaning with a 2000 ppm NaOCl solution for 1 h. Effective permeability recovery by hypochlorite cleaning was demonstrated with multiple hypochlorite cleaning cycles. Membrane fouling and hypochlorite cleaning were also simulated using solutions containing a model foulant (sodium alginate, humic acids or bovine serum albumin). Among them, an insufficient permeability recovery was observed for membrane fouling caused by humic acids. Further research is recommended to develop an improved hypochlorite cleaning protocol to control various membrane fouling.

Tout, J, Astudillo‐García, C, Taylor, MW, Tyson, GW, Stocker, R, Ralph, PJ, Seymour, JR & Webster, NS 2017, 'Redefining the sponge‐symbiont acquisition paradigm: sponge microbes exhibit chemotaxis towards host‐derived compounds', Environmental Microbiology Reports, vol. 9, no. 6, pp. 750-755.
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SummaryMarine sponges host stable and species‐specific microbial symbionts that are thought to be acquired and maintained by the host through a combination of vertical transmission and filtration from the surrounding seawater. To assess whether the microbial symbionts also actively contribute to the establishment of these symbioses, we performed in situ experiments on Orpheus Island, Great Barrier Reef, to quantify the chemotactic responses of natural populations of seawater microorganisms towards cellular extracts of the reef sponge Rhopaloeides odorabile. Flow cytometry analysis revealed significant levels of microbial chemotaxis towards R. odorabile extracts and 16S rRNA gene amplicon sequencing showed enrichment of ‘sponge‐specific’ microbial phylotypes, including a cluster within the Gemmatimonadetes and another within the Actinobacteria. These findings infer a potential mechanism for how sponges can acquire bacterial symbionts from the surrounding environment and suggest an active role of the symbionts in finding their host.

Tran, HN, You, S-J, Nguyen, TV & Chao, H-P 2017, 'Insight into the adsorption mechanism of cationic dye onto biosorbents derived from agricultural wastes', Chemical Engineering Communications, vol. 204, no. 9, pp. 1020-1036.
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© 2017 Taylor & Francis. This study investigated the phenomenon and mechanism of adsorption of methylene green 5 (MG5) on three pristine biosorbents: golden shower pod (GS), coconut shell (CC), and orange peel (OP). The results showed that the biosorbents possessed low specific surface areas, but abundant functional groups. Adsorption was strongly affected by the solution’s pH and ionic strength. As revealed in the kinetic study, equilibrium was rapidly established, requiring low activation energies; a removal rate of 30%–87% was achieved within 1 min. The maximum Langmuir adsorption capacities at 30°C exhibited the following order: GS (106 mg/g) > OP (92 mg/g) > CC (59 mg/g). Thermodynamic experiments suggested that the adsorption occurred spontaneously and exothermically The primary adsorption mechanisms involved electrostatic attraction, hydrogen bonding formations, and n-π interaction. Thermogravimetric analysis (TGA) revealed that three biopolymer components (i.e., hemicellulose, cellulose, and lignin) played controlling roles in the adsorption process. Thus, these three agricultural residues can be considered potential low-cost adsorbents for efficient dye adsorption applications.

Tran, VH, Phuntsho, S, Park, H, Han, DS & Shon, HK 2017, 'Sulfur-containing air pollutants as draw solution for fertilizer drawn forward osmosis desalination process for irrigation use', Desalination, vol. 424, pp. 1-9.
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© 2017 Elsevier B.V. This study investigated suitability and performance of the sulfur-based seed solution (SBSS) as a draw solution (DS), a byproduct taken from the photoelectrochemical (PEC) process where the SBSS is used as an electrolyte for H2 production. This SBSS DS is composed of a mixture of ammonium sulfate ((NH4)2SO4) and ammonium sulfite ((NH4)2SO3), and it can be utilized as fertilizer for fertilizer drawn forward osmosis (FDFO) desalination of saline water. The FDFO process employed with thin-film composite (TFC) membrane and showed that the process performance (i.e. water flux and reverse salt flux) is better than that with cellulose triacetate (CTA) membrane. In addition, it produced high water flux of 19 LMH using SBSS as DS at equivalent concentration at 1 M and 5 g/L NaCl of feed solution (model saline water). Experimental results showed that the reverse salt flux of SBSS increased with the increase in pH of the DS and that lowering the concentration of ammonium sulfite in the SBSS led to the higher water flux of feed solution. The result also demonstrated that this SBSS is practically suitable for the FDFO process toward development of water-energy-food nexus technology using sulfur chemicals-containing air pollutant.

Tran, VS, Ngo, HH, Guo, W, Ton-That, C, Li, J, Li, J & Liu, Y 2017, 'Removal of antibiotics (sulfamethazine, tetracycline and chloramphenicol) from aqueous solution by raw and nitrogen plasma modified steel shavings', Science of The Total Environment, vol. 601-602, pp. 845-856.
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© 2017 Elsevier B.V. The removal of sulfamethazine (SMT), tetracycline (TC) and chloramphenicol (CP) from synthetic wastewater by raw (M3) and nitrogen plasma modified steel shavings (M3-plN2) was investigated using batch experiments. The adsorption kinetics could be expressed by both pseudo-first-order kinetic (PFO) and pseudo-second-order kinetic (PSO) models, where correlation coefficient r2 values were high. The values of PFO rate constant k1p and PSO rate constant k2p decreased as SMT-M3 > SMT-M3-plN2 > TC-M3-plN2 > TC-M3 > CP-M3 > CP-M3-plN2 and SMT-M3 > SMT-M3-plN2 > TC-M3 > TC-M3-plN2 > CP-M3 > CP-M3-plN2, respectively. Solution pH, adsorbent dose and temperature exerted great influences on the adsorption process. The plasma modification with nitrogen gas cleaned and enhanced 1.7-fold the surface area and 1.4-fold the pore volume of steel shavings. Consequently, the removal capacity of SMT, TC, CP on the adsorbent rose from 2519.98 to 2702.55, 1720.20 to 2158.36, and 2772.81 to 2920.11 μg/g, respectively. Typical chemical states of iron (XPS in Fe2p3 region) in the adsorbents which are mainly responsible for removing antibiotics through hydrogen bonding, electrostatic and non- electrostatic interactions and redox reaction were as follows: Fe3O4/Fe2 +, Fe3O4/Fe3 +, FeO/Fe2 + and Fe2O3/Fe3 +.

Trevathan-Tackett, SM, Macreadie, PI, Sanderman, J, Baldock, J, Howes, JM & Ralph, PJ 2017, 'A Global Assessment of the Chemical Recalcitrance of Seagrass Tissues: Implications for Long-Term Carbon Sequestration', Frontiers in Plant Science, vol. 8.
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© 2017 Trevathan-Tackett, Macreadie, Sanderman, Baldock, Howes and Ralph. Seagrass ecosystems have recently been identified for their role in climate change mitigation due to their globally-significant carbon sinks; yet, the capacity of seagrasses to sequester carbon has been shown to vary greatly among seagrass ecosystems. The recalcitrant nature of seagrass tissues, or the resistance to degradation back into carbon dioxide, is one aspect thought to influence sediment carbon stocks. In this study, a global survey investigated how the macromolecular chemistry of seagrass leaves, sheaths/stems, rhizomes and roots varied across 23 species from 16 countries. The goal was to understand how this seagrass chemistry might influence the capacity of seagrasses to contribute to sediment carbon stocks. Three non-destructive analytical chemical analyses were used to investigate seagrass chemistry: thermogravimetric analysis (TGA) and solid state13 C-NMR and infrared spectroscopy. A strong latitudinal influence on carbon quality was found, whereby temperate seagrasses contained 5% relatively more labile carbon, and tropical seagrasses contained 3% relatively more refractory carbon. Sheath/stem tissues significantly varied across taxa, with larger morphologies typically containing more refractory carbon than smaller morphologies. Rhizomes were characterized by a higher proportion of labile carbon (16%of total organic matter compared to 8–10%in other tissues); however, high rhizome biomass production and slower remineralization in anoxic sediments will likely enhance these below-ground tissues’ contributions to long-termcarbon stocks. Our study provides a standardized and global dataset on seagrass carbon quality across tissue types, taxa and geography that can be incorporated in carbon sequestration and storage models as well as ecosystem valuation and management strategies.

Trevathan-Tackett, SM, Seymour, JR, Nielsen, DA, Macreadie, PI, Jeffries, TC, Sanderman, J, Baldock, J, Howes, JM, Steven, ADL & Ralph, PJ 2017, 'Sediment anoxia limits microbial-driven seagrass carbon remineralization under warming conditions', FEMS Microbiology Ecology, vol. 93, no. 6.
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© FEMS 2017. All rights reserved. Seagrass ecosystems are significant carbon sinks, and their resident microbial communities ultimately determine the quantity and quality of carbon sequestered. However, environmental perturbations have been predicted to affect microbial-driven seagrass decomposition and subsequent carbon sequestration. Utilizing techniques including 16S-rDNA sequencing, solid-state NMR and microsensor profiling, we tested the hypothesis that elevated seawater temperatures and eutrophication enhance the microbial decomposition of seagrass leaf detritus and rhizome/root tissues. Nutrient additions had a negligible effect on seagrass decomposition, indicating an absence of nutrient limitation. Elevated temperatures caused a 19% higher biomass loss for aerobically decaying leaf detritus, coinciding with changes in bacterial community structure and enhanced lignocellulose degradation. Although, community shifts and lignocellulose degradation were also observed for rhizome/root decomposition, anaerobic decay was unaffected by temperature. These observations suggest that oxygen availability constrains the stimulatory effects of temperature increases on bacterial carbon remineralization, possibly through differential temperature effects on bacterial functional groups, including putative aerobic heterotrophs (e.g. Erythrobacteraceae, Hyphomicrobiaceae) and sulfate reducers (e.g. Desulfobacteraceae). Consequently, under elevated seawater temperatures, carbon accumulation rates may diminish due to higher remineralization rates at the sediment surface. Nonetheless, the anoxic conditions ubiquitous to seagrass sediments can provide a degree of carbon protection under warming seawater temperatures.

Uchiyama, M, Satoh, K, McKenzie, TG, Fu, Q, Qiao, GG & Kamigaito, M 2017, 'Diverse approaches to star polymers via cationic and radical RAFT cross-linking reactions using mechanistic transformation', Polymer Chemistry, vol. 8, no. 38, pp. 5972-5981.
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Core cross-linked star polymers were synthesizedviacationic RAFT polymerization and three different approaches in combination with a radical RAFT mechanism.

van den Engh, GJ, Doggett, JK, Thompson, AW, Doblin, MA, Gimpel, CNG & Karl, DM 2017, 'Dynamics of Prochlorococcus and Synechococcus at Station ALOHA Revealed through Flow Cytometry and High-Resolution Vertical Sampling', Frontiers in Marine Science, vol. 4, no. NOV.
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© 2017 van den Engh, Doggett, Thompson, Doblin, Gimpel and Karl. The fluorescence and scattering properties of Prochlorococcus and Synechococcus at Station ALOHA as measured by flow cytometry (termed the FCM phenotype) vary with depth and over a variety of time scales. The variation in FCM phenotypes may reflect population selection or physiological acclimation to local conditions. Observations before, during, and after a storm with deep water mixing show a short-term homogenization of the FCM phenotypes with depth, followed by a return to the stable pattern over the time span of a few days. These dynamics indicate that, within the upper mixed-layer, the FCM phenotype distribution represents acclimation to ambient light. The populations in the pycnocline (around 100 m and below), remain stable and are invariant with light conditions. In samples where both cyanobacteria coexist, fluorescence properties of Prochlorococcus and Synechococcus are tightly correlated providing further evidence that FCM phenotype variability is caused by a common environmental factor or factors. Measurements of the dynamics of FCM phenotypes provide insights into phytoplankton physiology and adaptation. Alternatively, FCM phenotype census of a water mass may provide information about its origin and illumination history.

Van Ngoc, P, Turner, B, Huang, J & Kelly, R 2017, 'Experimental study on the durability of soil-cement columns in coastal areas', Geotechnical Engineering, vol. 48, no. 4, pp. 138-143.
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Deep soil mixing is one of the most commonly used ground improvement techniques. With high sulphate content in soil and seawater, stabilised soil in coastal areas can deteriorate due to sulphate attack. In this research, the degradation in strength of cement treated soil exposed to synthetic seawater is measured by uniaxial compression and needle penetration testing. Three exposure conditions, namely 100% seawater, 200% seawater and sealed condition (control samples), were used to measure the deterioration level due to the effect of sulphate. In addition, the extent of the portlandite consumption was also measured by Thermogravimetric Analysis which reflects the calcium distribution in the soil-cement columns. The test results show that the deterioration occurs deeper and faster in higher seawater environments. Furthermore, in contact with increasing sulphate concentration, the deterioration shows a close relation with calcium distribution.

Van Nguyen, Q, Fatahi, B & Hokmabadi, AS 2017, 'Influence of Size and Load-Bearing Mechanism of Piles on Seismic Performance of Buildings Considering Soil–Pile–Structure Interaction', International Journal of Geomechanics, vol. 17, no. 7, pp. 04017007-04017007.
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© 2017 American Society of Civil Engineers. Pile foundations are usually used to transmit foundation loads through soil strata of low bearing capacity to deeper soil or rock strata with a higher bearing capacity and stiffness. The type and size of a pile foundation that supports midrise buildings in high-risk seismic zones can alter the dynamic characteristics of the soil-pile-foundation system during an earthquake due to soil-structure interaction. To investigate these phenomena, a 15-story moment-resisting frame sitting on differently sized end-bearing and floating pile foundations was simulated numerically. The present paper describes a numerical modeling technique for the simulation of complex seismic soil-pile-structure interaction phenomena. By adopting a method of direct calculation, the numerical model can perform a fully nonlinear time history dynamic analysis to realistically simulate the dynamic behavior of soil, pile foundations, and structure under seismic excitations. This three-dimensional (3D) numerical model accounts for the nonlinear behavior of the soil medium, the piles, and the structural elements. Results show that the type and size of the pile elements influence the dynamic characteristics and seismic response of the building due to interaction between the soil, pile foundations, and the structure. The findings of this study can help engineers select the correct size and type of pile foundation while considering the seismic performance of buildings sitting on soft soil and aim at optimizing their design.

Vu, TM, Trinh, VT, Doan, DP, Van, HT, Nguyen, TV, Vigneswaran, S & Ngo, HH 2017, 'Removing ammonium from water using modified corncob-biochar', Science of The Total Environment, vol. 579, pp. 612-619.
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© 2016 Elsevier B.V. Ammonium pollution in groundwater and surface water is of major concern in many parts of the world due to the danger it poses to the environment and people's health. This study focuses on the development of a low cost adsorbent, specifically a modified biochar prepared from corncob. Evaluated here is the efficiency of this new material for removing ammonium from synthetic water (ammonium concentration from 10 to 100 mg/L). The characteristics of the modified biochar were determined by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). It was found that ammonium adsorption on modified biochar strongly depended on pH. Adsorption kinetics of NH4+-N using modified biochar followed the pseudo-second order kinetic model. Both Langmuir and Sips adsorption isotherm models could simulate well the adsorption behavior of ammonium on modificated biochar. The highest adsorption capacity of 22.6 mg NH4+-N/g modified biochar was obtained when the biochar was modified by soaking it in HNO3 6 M and NaOH 0.3 M for 8 h and 24 h, respectively. The high adsorption capacity of the modified biochar suggested that it is a promising adsorbent for NH4+-N remediation from water.

Wang, C, Gao, B, Zhao, P, Li, R, Yue, Q & Shon, HK 2017, 'Exploration of polyepoxysuccinic acid as a novel draw solution in the forward osmosis process', RSC Advances, vol. 7, no. 49, pp. 30687-30698.
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Polyepoxysuccinic acid (PESA) is a green corrosion scale inhibitor.

Wang, D, Fu, Q, Xu, Q, Liu, Y, Hao Ngo, H, Yang, Q, Zeng, G, Li, X & Ni, B-J 2017, 'Free nitrous acid-based nitrifying sludge treatment in a two-sludge system enhances nutrient removal from low-carbon wastewater', Bioresource Technology, vol. 244, no. Part 1, pp. 920-928.
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© 2017 Elsevier Ltd A new method to enhance nutrient removal from low carbon-wastewater was developed. The method consists of a two-sludge system (i.e., an anaerobic-anoxic-oxic reactor coupled to a nitrifying reactor (N-SBR)) and a nitrifying-sludge treatment unit using free nitrous acid (FNA). Initially, 65.1 ± 2.9% in total nitrogen removal and 69.6 ± 3.4% in phosphate removal were obtained without nitrite accumulation. When 1/16 of the nitrifying sludge was daily treated with FNA at 1.1 mg N/L for 24 h, ∼28.5% of nitrite was accumulated in the N-SBR, and total nitrogen and phosphate removal increased to 72.4 ± 3.2% and 76.7 ± 2.9%, respectively. About 67.8% of nitrite was accumulated at 1.9 mg N/L FNA, resulting in 82.9 ± 3.8% in total nitrogen removal and 87.9 ± 3.5% in phosphate removal. Fluorescence in-situ hybridization analysis showed that FNA treatment reduced the abundance of nitrite oxidizing bacteria (NOB), especially that of Nitrospira sp.

Wang, D, Liu, Y, Ngo, HH, Zhang, C, Yang, Q, Peng, L, He, D, Zeng, G, Li, X & Ni, B-J 2017, 'Approach of describing dynamic production of volatile fatty acids from sludge alkaline fermentation', Bioresource Technology, vol. 238, pp. 343-351.
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© 2017 Elsevier Ltd In this work, a mathematical model was developed to describe the dynamics of fermentation products in sludge alkaline fermentation systems for the first time. In this model, the impacts of alkaline fermentation on sludge disintegration, hydrolysis, acidogenesis, acetogenesis, and methanogenesis processes are specifically considered for describing the high-level formation of fermentation products. The model proposed successfully reproduced the experimental data obtained from five independent sludge alkaline fermentation studies. The modeling results showed that alkaline fermentation largely facilitated the disintegration, acidogenesis, and acetogenesis processes and severely inhibited methanogenesis process. With the pH increase from 7.0 to 10.0, the disintegration, acidogenesis, and acetogenesis processes respectively increased by 53%, 1030%, and 30% while methane production decreased by 3800%. However, no substantial effect on hydrolysis process was found. The model also indicated that the pathway of acetoclastic methanogenesis was more severely inhibited by alkaline condition than that of hydrogentrophic methanogenesis.

Wang, D, Wang, Y, Liu, Y, Ngo, HH, Lian, Y, Zhao, J, Chen, F, Yang, Q, Zeng, G & Li, X 2017, 'Is denitrifying anaerobic methane oxidation-centered technologies a solution for the sustainable operation of wastewater treatment Plants?', Bioresource Technology, vol. 234, pp. 456-465.
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With the world's increasing energy crisis, society is growingly considered that the operation of wastewater treatment plants (WWTPs) should be shifted in sustainable paradigms with low energy input, or energy-neutral, or even energy output. There is a lack of critical thinking on whether and how new paradigms can be implemented in WWTPs based on the conventional process. The denitrifying anaerobic methane oxidation (DAMO) process, which uses methane and nitrate (or nitrite) as electron donor and acceptor, respectively, has recently been discovered. Based on critical analyses of this process, DAMO-centered technologies can be considered as a solution for sustainable operation of WWTPs. In this review, a possible strategy with DAMO-centered technologies was outlined and illustrated how this applies for the existing WWTPs energy-saving and newly designed WWTPs energy-neutral (or even energy-producing) towards sustainable operations.

Wang, J, Pathak, N, Chekli, L, Phuntsho, S, Kim, Y, Li, D & Shon, H 2017, 'Performance of a Novel Fertilizer-Drawn Forward Osmosis Aerobic Membrane Bioreactor (FDFO-MBR): Mitigating Salinity Build-Up by Integrating Microfiltration', Water, vol. 9, no. 1, pp. 21-21.
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© 2017 by the authors. In this paper, three different fertilizer draw solutions were tested in a novel forward osmosis-microfiltration aerobic membrane bioreactor (MF-FDFO-MBR) hybrid system and their performance were evaluated in terms of water flux and reverse salt diffusion. Results were also compared with a standard solution. Results showed that ammonium sulfate is the most suitable fertilizer for this hybrid system since it has a relatively high water flux (6.85 LMH) with a comparatively low reverse salt flux (3.02 gMH). The performance of the process was also studied by investigating different process parameters: draw solution concentration, FO draw solution flow rate and MF imposed flux. It was found that the optimal conditions for this hybrid system were: draw solution concentration of 1 M, FO draw solution flow rate of 200 mL/min and MF imposed flux of 10 LMH. The salt accumulation increased from 834 to 5400 μS/cm during the first four weeks but after integrating MF, the salinity dropped significantly from 5400 to 1100 μS/cm suggesting that MF is efficient in mitigating the salinity build up inside the reactor. This study demonstrated that the integration of the MF membrane could effectively control the salinity and enhance the stable FO flux in the OMBR.

Wang, Q 2017, 'A Roadmap for Achieving Energy-Positive Sewage Treatment Based on Sludge Treatment Using Free Ammonia', ACS Sustainable Chemistry & Engineering, vol. 5, no. 11, pp. 9630-9633.
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This letter proposes an innovative roadmap for achieving energy-positive sewage treatment based on sludge treatment using free ammonia (FA, i.e., NH3). This FA technology is able to enhance anaerobic energy recovery in the form of methane via pretreatment of primary sludge and/or secondary sludge. It can also achieve stable mainstream nitrogen removal via nitrite instead of nitrate, thereby increasing organics availability for energy recovery. Energy evaluation suggests that the FA technology could transform sewage treatment plants from energy consumers (energy consumption at 0.27 kWh/m3 sewage treated) to energy exporters (energy export at 0.14 kWh/m3 sewage treated). Economic and environmental evaluations indicate that the FA technology would reduce sewage treatment cost and CO2 emission by $0.056/m3 sewage treated and 0.40 kg CO2/m3 sewage treated, respectively. This FA technology is a sustainable and closed-loop technology, which requires negligible chemical/energy input with FA being a byproduct of sewage treatment. It is also easy to implement in any existing and new sewage treatment plants by adding a simple sludge mixing tank.

Wang, Q, Duan, H, Wei, W, Ni, B-J, Laloo, A & Yuan, Z 2017, 'Achieving Stable Mainstream Nitrogen Removal via the Nitrite Pathway by Sludge Treatment Using Free Ammonia', Environmental Science & Technology, vol. 51, no. 17, pp. 9800-9807.
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© 2017 American Chemical Society. Biological nitrogen removal through the nitrite pathway (NH4+ → NO2- → N2) is favorable for wastewater treatment plants without sufficient carbon sources. This study demonstrates an innovative approach for attaining the nitrite pathway based on sludge treatment using free ammonia (FA, i.e., NH3). This approach is based on our innovative discovery in this study that FA at 210 mg NH3-N/L is far less biocidal to ammonium-oxidizing bacteria (AOB) than to nitrite-oxidizing bacteria (NOB). A total of 22% of the activated sludge from the sequencing batch reactor (SBR) receiving synthetic domestic wastewater was treated in an FA treatment unit at 210 mg NH3-N/L for 1 day. The FA-treated sludge was afterward recirculated back to the SBR. A nitrite accumulation ratio of above 90% was quickly achieved (in 40 days) and maintained stably in the SBR, indicating the establishment of the nitrite pathway. The NOB population and activity after implementing FA treatment was less than 5% of those without FA treatment, suggesting the washout of NOB. In contrast, the AOB population and activity in the SBR were not affected. The nitrogen-removal performance was significantly improved after incorporating the FA approach. The FA approach is a closed-loop approach and is economically and environmentally attractive.

Wang, Q, Wei, W, Gong, Y, Yu, Q, Li, Q, Sun, J & Yuan, Z 2017, 'Technologies for reducing sludge production in wastewater treatment plants: State of the art', Science of The Total Environment, vol. 587-588, pp. 510-521.
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This review presents the state-of-the-art sludge reduction technologies applied in both wastewater and sludge treatment lines. They include chemical, mechanical, thermal, electrical treatment, addition of chemical un-coupler, and predation of protozoa/metazoa in wastewater treatment line, and physical, chemical and biological pretreatment in sludge treatment line. Emphasis was put on their effect on sludge reduction performance, with 10% sludge reduction to zero sludge production in wastewater treatment line and enhanced TS (total solids) or volatile solids removal of 5-40% in sludge treatment line. Free nitrous acid (FNA) technology seems good in wastewater treatment line but it is only under the lab-scale trial. In sludge treatment line, thermal, ultrasonic (<4400kJ/kg TS), FNA pretreatment and temperature-phased anaerobic digestion (TPAD) are promising if pathogen inactivation is not a concern. However, thermal pretreatment and TPAD are superior to other pretreatment technologies when pathogen inactivation is required. The new wastewater treatment processes including SANI®, high-rate activated sludge coupled autotrophic nitrogen removal and anaerobic membrane bioreactor coupled autotrophic nitrogen removal also have a great potential to reduce sludge production. In the future, an effort should be put on the effect of sludge reduction technologies on the removal of organic micropollutants and heavy metals.

Wang, Y, Wang, C, Guo, H, Wang, Y & Huang, Z 2017, 'A nitrogen-doped three-dimensional carbon framework for high performance sodium ion batteries', RSC Advances, vol. 7, no. 3, pp. 1588-1592.
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A nitrogen-doped three-dimensional carbon framework is synthesized, and shows good Na⁺ storage performance with excellent rate capability.

Wang, Y, Wang, D, Liu, Y, Wang, Q, Chen, F, Yang, Q, Li, X, Zeng, G & Li, H 2017, 'Triclocarban enhances short-chain fatty acids production from anaerobic fermentation of waste activated sludge', Water Research, vol. 127, pp. 150-161.
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© 2017 Elsevier Ltd Triclocarban (TCC), one typical antibacterial agent being widely used in various applications, was found to be present in waste activated sludge at significant levels. To date, however, its effect on anaerobic fermentation of sludge has not been investigated. This work therefore aims to fill this knowledge gap. Experimental results showed that when TCC content in sludge increased from 26.7 ± 5.3 to 520.5 ± 12.6 mg per kilogram total suspended solids, the maximum concentration of short-chain fatty acids (SCFA) increased from 32.6 ± 2.5 to 228.2 ± 3.6 (without pH control) and from 211.7 ± 2.4 to 378.3 ± 3.2 mg COD/g VSS (initial pH 10), respectively. The large promotion of acetic acid was found to be the major reason for the enhancement of total SCFA production. Although a significant level of TCC was degraded in the fermentation process, SCFA was neither produced from TCC nor affected by its major intermediates at the relevant levels. It was found that TCC facilitated solubilization, acidogenesis, acetogenesis, and homoacetogenesis processes but inhibited methanogenesis process. Microbial analysis revealed that the increase of TCC increased the microbial community diversity, the abundances of SCFA (especially acetic acid) producers, and the activities of key enzymes relevant to acetic acid production.

Wangpraseurt, D, Holm, JB, Larkum, AWD, Pernice, M, Ralph, PJ, Suggett, DJ & Kühl, M 2017, 'In vivo Microscale Measurements of Light and Photosynthesis during Coral Bleaching: Evidence for the Optical Feedback Loop?', Frontiers in Microbiology, vol. 8, no. JAN, pp. 1-12.
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© 2017 Wangpraseurt, Holm, Larkum, Pernice, Ralph, Suggett and Kühl. Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment. We created tissue areas with different densities of Symbiodinium cells in order to understand the optical properties and light microenvironment of corals during bleaching. Our results showed that in bleached Pocillopora damicornis corals, Symbiodinium light exposure was up to fivefold enhanced relative to healthy corals, and the relationship between symbiont loss and light enhancement was well-described by a power-law function. Cell-specific rates of Symbiodinium gross photosynthesis and light respiration were enhanced in bleached P. damicornis compared to healthy corals, while areal rates of net photosynthesis decreased. Symbiodinium light exposure in Favites sp. revealed the presence of low light microniches in bleached coral tissues, suggesting that light scattering in thick coral tissues can enable photoprotection of cryptic symbionts. Our study provides evidence for the acceleration of in vivo light exposure during coral bleaching but this optical feedback mechanism differs between coral hosts. Enhanced photosynthesis in relation to accelerating light exposure shows that coral microscale optics exerts a key role on coral photophysiology and the subsequent degree of radiative stress during coral bleaching.

Wei, D, Zhang, K, Ngo, HH, Guo, W, Wang, S, Li, J, Han, F, Du, B & Wei, Q 2017, 'Nitrogen removal via nitrite in a partial nitrification sequencing batch biofilm reactor treating high strength ammonia wastewater and its greenhouse gas emission', Bioresource Technology, vol. 230, pp. 49-55.
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© 2017 Elsevier Ltd In present study, the feasibility of partial nitrification (PN) process achievement and its greenhouse gas emission were evaluated in a sequencing batch biofilm reactor (SBBR). After 90 days’ operation, the average effluent NH4+-N removal efficiency and nitrite accumulation rate of PN-SBBR were high of 98.2% and 87.6%, respectively. Both polysaccharide and protein contents were reduced in loosely bound extracellular polymeric substances (LB-EPS) and tightly bound EPS (TB-EPS) during the achievement of PN-biofilm. Excitation-emission matrix spectra implied that aromatic protein-like, tryptophan protein-like and humic acid-like substances were the main compositions of both kinds of EPS in seed sludge and PN-biofilm. According to typical cycle, the emission rate of CO2had a much higher value than that of N2O, and their total amounts per cycle were 67.7 and 16.5 mg, respectively. Free ammonia (FA) played a significant role on the inhibition activity of nitrite-oxidizing bacteria and the occurrence of nitrite accumulation.

Wei, W, Zhou, X, Wang, D, Sun, J & Wang, Q 2017, 'Free ammonia pre-treatment of secondary sludge significantly increases anaerobic methane production', Water Research, vol. 118, pp. 12-19.
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Energy recovery in the form of methane from sludge/wastewater is restricted by the poor and slow biodegradability of secondary sludge. An innovative pre-treatment technology using free ammonia (FA, i.e. NH3) was proposed in this study to increase anaerobic methane production. The solubilisation of secondary sludge was significantly increased after FA pre-treatment at up to 680 mg NH3-N/L for 1 day, under which the solubilisation (i.e. 0.4 mg SCOD/mg VS; SCOD: soluble chemical oxygen demand; VS: volatile solids) was >10 times higher than that without FA pre-treatment (i.e. 0.03 mg SCOD/mg VS). Biochemical methane potential assays showed that FA pre-treatment at above 250 mg NH3-N/L is effective in improving anaerobic methane production. The highest improvement in biochemical methane potential (B0) and hydrolysis rate (k) was achieved at FA concentrations of 420-680 mg NH3-N/L, and was determined as approximately 22% (from 160 to 195 L CH4/kg VS added) and 140% (from 0.22 to 0.53 d-1) compared to the secondary sludge without pre-treatment. More analysis revealed that the FA induced improvement in B0 and k could be attributed to the rapidly biodegradable substances rather than the slowly biodegradable substances. Economic and environmental analyses showed that the FA-based technology is economically favourable and environmentally friendly. Since this FA technology aims to use the wastewater treatment plants (WWTPs) waste (i.e. anaerobic digestion liquor) to enhance methane production from the WWTPs, it will set an example for the paradigm shift of the WWTPs from 'linear economy' to 'circular economy'.

Wei, W, Zhou, X, Xie, G, Duan, H & Wang, Q 2017, 'A novel free ammonia based pretreatment technology to enhance anaerobic methane production from primary sludge', Biotechnology and Bioengineering, vol. 114, no. 10, pp. 2245-2252.
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ABSTRACTThis study proposed a novel free ammonia (FA, i.e., NH3) pretreatment technology to enhance anaerobic methane production from primary sludge for the first time. The solubilization of primary sludge was substantially enhanced following 24 h FA pretreatment (250–680 mg NH3‐N/L), by which the release of soluble chemical oxygen demand (SCOD) (i.e., 0.4 mg SCOD/mg VS added; VS: volatile solids) was approximately 10 times as much as that without pretreatment (i.e., 0.03 mg SCOD/mg VS added). Then, biochemical methane potential (BMP) tests demonstrated that FA pretreatment of 250–680 mg NH3‐N/L was capable of enhancing anaerobic methane production while the digestion time was more than 7 days. Model based analysis indicated that the improved anaerobic methane production was due to an increased biochemical methane potential (B0) of 8–17% (i.e., from 331 to 357–387 L CH4/kg VS added), with the highest B0 achieved at 420 mg NH3‐N/L pretreatment. However, FA pretreatment of 250–680 mg NH3‐N/L decreased hydrolysis rate (k) by 24–38% compared with control (i.e., from 0.29 d−1 to 0.18–0.22 d−1), which explained the lower methane production over the first 7 days’ digestion period. Economic analysis and environmental evaluation demonstrated that FA pretreatment technology was environmentally friendly and economically favorable. Biotechnol. Bioeng. 2017;114: 2245–2252. © 2017 Wiley Periodicals, Inc.

Wilkinson, AD, Collier, CJ, Flores, F, Langlois, L, Ralph, PJ & Negri, AP 2017, 'Combined effects of temperature and the herbicide diuron on Photosystem II activity of the tropical seagrass Halophila ovalis', Scientific Reports, vol. 7, no. 1, pp. 1-11.
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AbstractTropical seagrasses are at their highest risk of exposure to photosystem II (PSII) herbicides when elevated rainfall and runoff from farms transports these toxicants into coastal habitats during summer, coinciding with periods of elevated temperature. PSII herbicides, such as diuron, can increase the sensitivity of corals to thermal stress, but little is known of the potential for herbicides to impact the thermal optima of tropical seagrass. Here we employed a well-plate approach to experimentally assess the effects of diuron on the photosynthetic performance of Halophila ovalis leaves across a 25 °C temperature range (36 combinations of these stressors across 15–40 °C). The thermal optimum for photosynthetic efficiency (▵'Equation missing') in H. ovalis was 31 °C while lower and higher temperatures reduced ▵'Equation missing' as did all elevated concentrations of diuron. There were significant interactions between the effects of temperature and diuron, with a majority of the combined stresses causing sub-additive (antagonistic) effects. However, both stressors caused negative responses and the sum of the responses was greater than that caused by temperature or diuron alone. These results indicate that improving water quality (reducing herbicide in runoff) is likely to maximise seagrass health during extreme temperature events that will become more common as the climate changes.

Wilkinson, S, Stoller, P, Ralph, P, Hamdorf, B, Catana, LN & Kuzava, GS 2017, 'Exploring the Feasibility of Algae Building Technology in NSW', Procedia Engineering, vol. 180, pp. 1121-1130.
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© 2017 The Authors. Published by Elsevier Ltd. For some time, Biochemists have been exploring the potential to produce biofuels as an alternative to fossil fuel energy. Biofuels can be derived from crops such as corn, soybean and sugarcane however these crops can contribute to water scarcity and deforestation. Furthermore, large areas of land are used that could otherwise be used for food production. Another possibility is to use microalgae, which does not have the disadvantages associated with crop-based biofuels. Depending on conditions, microalgae can produce bio compounds that are converted into biofuels. The built environment is responsible for around 40 to 50% of total greenhouse gas emissions through fossil fuel consumption. Not only is it necessary to design and to retrofit our built environment to be more energy efficient, but it is also necessary to consider alternative fuel sources. To date, this has mostly focused on solar, wind and geothermal sources, however one residential building in Hamburg Germany has adopted algae building technology in the form of façade panels which act as a source of energy for heating the apartments and for hot water. The climate in northern Germany is very different to Australia, and the question arises; what is the feasibility to adopt algae building technology in New South Wales? There are issues around the physical and technical aspects of the technology, the social and environmental aspects, the regulatory and planning aspects, as well as the economic considerations. This paper reports on a study with key stakeholders in New South Wales to explore barriers and drivers associated with the adoption of algae building technology.

Woo, YC, Tijing, LD, Park, MJ, Yao, M, Choi, J-S, Lee, S, Kim, S-H, An, K-J & Shon, HK 2017, 'Electrospun dual-layer nonwoven membrane for desalination by air gap membrane distillation', Desalination, vol. 403, pp. 187-198.
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© 2015 Elsevier B.V. In the present study, dual-layer nanofiber nonwoven membranes were prepared by a facile electrospinning technique and applied for desalination by air gap membrane distillation (AGMD). Neat single and dual-layer nanofiber membranes composed of a hydrophobic polyvinylidene fluoride-co-hexafluoropropylene (PH) top layer with different supporting hydrophilic layer made of either polyvinyl alcohol (PVA), nylon-6 (N6), or polyacrylonitrile (PAN) nanofibers were fabricated with and without heat-press post-treatment. Surface characterization showed that the active layer (i.e., PH) of all electrospun nanofiber membranes (ENMs) exhibited a rough, highly porous (> 80% porosity), and hydrophobic surface (CA > 140°), while the other side was hydrophilic (CA < 90°) with varying porosity. Heat-pressing the membrane resulted to thinner thickness (from > 129 μm to < 100 μm) and smaller pore sizes (< 0.27 μm). The AGMD experiments in a co-current flow set-up were carried out with constant inlet temperatures at the feed and permeate streams of 60 ± 1.5 and 20 ± 1.5° C, respectively. The AGMD module had a membrane area of 21 cm2 and the thickness of the air gap was 3 mm. The neat single and dual-layer ENMs showed a water permeate flux of about 10.9–15.5 L/m2 h (LMH) using 3.5 wt.% NaCl solution as feed, which was much higher than that of a commercial PVDF membrane (~ 5 LMH). The provision of a hydrophilic layer at the bottom layer enhanced the AGMD performance depending on the wettability and characteristics of the support layer. The PH/N6 dual-layer nanofiber membrane prepared under the optimum condition showed flux and salt rejection of 15.5 LMH and 99.2%, respectively, which has good potential for AGMD application.

Wu, B, Ni, B-J, Horvat, K, Song, L, Chai, X, Dai, X & Mahajan, D 2017, 'Occurrence State and Molecular Structure Analysis of Extracellular Proteins with Implications on the Dewaterability of Waste-Activated Sludge', Environmental Science & Technology, vol. 51, no. 16, pp. 9235-9243.
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© 2017 American Chemical Society. The occurrence state and molecular structure of extracellular proteins were analyzed to reveal the influencing factors on the water-holding capacities of protein-like substances in waste-activated sludge (WAS). The gelation process of extracellular proteins verified that advanced oxidation processes (AOPs) for WAS dewaterability improvement eliminated the water affinity of extracellular proteins and prevented these macromolecules from forming stable colloidal aggregates. Isobaric tags for relative and absolute quantitation proteomics identified that most of the extracellular proteins were originally derived from the intracellular part and the proteins originally located in the extracellular part were mainly membrane-associated. The main mechanism of extracellular protein transformation during AOPs could be represented by the damage of the membrane or related external encapsulating structure and the release of intracellular substances. For the selected representative extracellular proteins, the strong correlation (R2 > 0.97, p < 0.03) between the surface hydrophilicity index and α-helix percentages in the secondary structure indicated that the water affinity relied more on the spatial distribution of hydrophilic functional groups rather than the content. Destructing the secondary structure represented by the α-helix and stretching the polypeptide aggregation in the water phase through disulfide bond removal might be the key to eliminating the inhibitory effects of extracellular proteins on the interstitial water removal from WAS.

Wu, H, Zhang, J, Ngo, HH, Guo, W & Liang, S 2017, 'Evaluating the sustainability of free water surface flow constructed wetlands: Methane and nitrous oxide emissions', Journal of Cleaner Production, vol. 147, pp. 152-156.
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© 2017 Elsevier Ltd Constructed wetlands (CWs) have been used as a green technology to treat various wastewaters for several decades, and greenhouse gases production in these systems attracted increasing attention considering the contributions of methane and nitrous oxide emissions to global warming. However, the detailed knowledge about the contribution of CWs to methane and nitrous oxide emissions in treating sewage treatment plant effluent are still limited in particular for a better understanding of the sustainability of CWs. The fluxes of methane (CH 4 ) and nitrous oxide (N 2 O) from free water surface (FWS) CWs in northern China were measured continuously using the static-stationary chamber technique from 2012 to 2013. The results showed that CWs were the significant source of CH 4 and N 2 O emissions. Average emission rates of CH 4 and N 2 O ranged from −30.2 μg m −2 h −1 to 450.9 μg m −2 h −1 , and -58.8 μg m −2 h −1 to 1251.8 μg m −2 h −1 , respectively. Obvious annual and seasonal variations of CH 4 and N 2 O emissions were observed over the 2-year period. In addition, temperatures and plant species had an impact on CH 4 and N 2 O emissions. The obtained results showed that FWS CWs, improving water quality but emitting lower CH 4 and N 2 O, could be the alternative method for sewage treatment plant effluent.

Wu, Y, Yang, Q, Zeng, Q, Ngo, HH, Guo, W & Zhang, H 2017, 'Enhanced low C/N nitrogen removal in an innovative microbial fuel cell (MFC) with electroconductivity aerated membrane (EAM) as biocathode', Chemical Engineering Journal, vol. 316, pp. 315-322.
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© 2016 Elsevier B.V. A novel microbial fuel cell (MFC) was developed to enhance simultaneous nitrification and denitrification (SND) by employing electrons from the anode. The cathode chamber of the reactor consisted of a membrane aerated biofilm reactor (MABR) which was made of an electroconductivity aerated membrane. The maximum power density of 4.20 ± 0.12 W m −3 was obtained at a current density of 4.10 ± 0.11 A m −2 (external resistance = 10 Ω). Compared with an open-circuit system, the removal rates of NH 4 + -N and TN were improved by 9.48 ± 0.33% and 19.80 ± 0.84%, respectively, which could be ascribed to the electrochemical denitrification. The anode (chemical oxygen demand, COD) and cathode (NO 3 − ) chambers reached the maximum coulombic efficiencies (CEs) of 40.67 ± 1.05% and 42.84 ± 1.14%, respectively. It suggested that the electroconductivity MABR has some advantages in controlling aeration intensity, thus improving SND and CEs. Overall, EAM-MFC could successfully generate electricity from wastewater whilst showing high capacity for removing nitrogen at a low COD/N ratio of 2.8 ± 0.07 g COD g −1 N.

Xiao, T, Nghiem, LD, Song, J, Bao, R, Li, X & He, T 2017, 'Phenol rejection by cellulose triacetate and thin film composite forward osmosis membranes', Separation and Purification Technology, vol. 186, pp. 45-54.
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© 2017 Elsevier B.V. This study aims to elucidate the separation of phenol by reverse osmosis (RO) and forward osmosis (FO) modes and propose strategies to enhance phenol rejection by these two processes. The results show that phenol rejection was strongly influenced by water flux, membrane materials, membrane structure, modes of operation, and feed solution chemistry (i.e. pH). The relationship between phenol rejection and water flux was demonstrated by the irreversible thermodynamic model which could accurately simulate phenol rejection as a function of water flux. At pH 7, phenol rejection by cellulose acetate (CTA) membranes was negligible while the thin film composite (TFC) polyamide (PA) membranes exhibited much higher phenol rejection. Through a systematic static adsorption experiment, results in this study show that phenol adsorption to CTA material was about 20 times higher than that to PA material. Thus, the observed higher phenol rejection by TFC PA compared to CTA membranes was attributed to the significantly higher affinity of phenol toward CTA and the sorption diffusion transport mechanism of phenol through the membrane. In particular, a TFC PA membrane specific for FO operation was prepared in this study. In FO mode, the tailor-made TFC PA membrane showed a slightly higher phenol rejection and a much higher water permeability compared to the commercial membrane. At the same water flux and solution pH, phenol rejection in FO mode was consistently higher than in RO mode. This observation could possibly be attributed to the reverse diffusion of draw solutes in the FO mode which hinders the forward diffusion of phenol through the membrane. A significant increase in phenol rejection was achieved by increasing the feed pH above the dissociation constant of the compound.

Xie, K, Fu, Q, Kim, J, Lu, H, He, Y, Zhao, Q, Scofield, J, Webley, PA & Qiao, GG 2017, 'Increasing both selectivity and permeability of mixed-matrix membranes: Sealing the external surface of porous MOF nanoparticles', Journal of Membrane Science, vol. 535, pp. 350-356.
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A novel approach to improve the selectivity of mixed matrix membrane (MMM) systems was developed. MOF nanoparticles (NPs) were chemical coated by a PEG based shell and then incorporated into a polymer matrix to yield a MMM. The unique design of the core-shell MOF NPs can enhance both the membrane permeability and selectivity simultaneously. This membrane material exhibits excellent CO2/N2 separation performance that surpasses the latest upper bound through the most direct way. This filler was also applied to the thin-film composite membrane system, showing promising performance and placing it in the optimal zone for post-combustion CO2 capture.

Xu, B, Ahmed, MB, Zhou, JL, Altaee, A, Wu, M & Xu, G 2017, 'Photocatalytic removal of perfluoroalkyl substances from water and wastewater: Mechanism, kinetics and controlling factors', Chemosphere, vol. 189, pp. 717-729.
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© 2017 Elsevier Ltd This review focuses on heterogeneous photocatalysis of perfluoroalkyl substances (PFAS) which are of worldwide concern as emerging persistent organic contaminants. Heterogeneous photocatalysis is an effective and advanced technology for PFAS removal from water with relatively high efficacy. During photocatalysis, various short chain perfluorocarboxylic acids (PFCA) are produced as intermediates and the efficacy is related to the photo-generated hole (h+) and photo-generated electron (e−). PFAS photodegradation in water under UV irradiation is most effective by using In2O3 as the catalyst, followed by Ga2O3 and TiO2. Significantly, modifying the chemical composition or morphology of the catalyst can improve its efficacy for PFAS removal. In2O3 porous nanoplates were found to have the best performance of 100% PFAS decomposition under UV light with rate constant (kt) and half-time (τ1/2) of 0.158 min−1 and 4.4 min, respectively. Catalysts perform well in acidic solution and increasing temperature to a certain extent. The photocatalytic performance is reduced when treating wastewater due to the presence of dissolved organic matter (DOM), with the catalysts following the order: needle-like Ga2O3 > In2O3 > TiO2. Future studies should focus on the development of novel photocatalysts, and their immobilization and application for PFAS removal in wastewater.

Xu, Q, Li, X, Ding, R, Wang, D, Liu, Y, Wang, Q, Zhao, J, Chen, F, Zeng, G, Yang, Q & Li, H 2017, 'Understanding and mitigating the toxicity of cadmium to the anaerobic fermentation of waste activated sludge', Water Research, vol. 124, pp. 269-279.
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© 2017 Elsevier Ltd Cadmium (Cd) is present in significant levels in waste activated sludge, but its potential toxicities on anaerobic fermentation of sludge remain largely unknown. This work therefore aims to provide such support. Experimental results showed that the impact of Cd on short-chain fatty acids (SCFA) production from sludge anaerobic fermentation was dose-dependent. The presence of environmentally relevant level of Cd (e.g., 0.1 mg/g VSS) enhanced SCFA production by 10.6%, but 10 mg/g VSS of Cd caused 68.1% of inhibition. Mechanism exploration revealed that although all levels of Cd did not cause extra leakage of intracellular substrates, 0.1 mg/g VSS Cd increased the contents of both soluble and loosely-bound extracellular polymeric substances (EPS), thereby benefitting sludge solubilization. On the contrary, 10 mg/g VSS Cd decreased the levels of all EPS layers, which reduced the content of soluble substrates. It was also found that 0.1 mg/g VSS Cd benefited both the hydrolysis and acidogenesis but 10 mg/g VSS Cd inhibited all the hydrolysis, acidogenesis, and methanogenesis processes. Further investigations with microbial community and enzyme analysis showed that the pertinent presence of Cd enhanced the activities of protease, acetate kinase, and oxaloacetate transcarboxylase whereas 10 mg/g VSS Cd decreased the microbial diversity, the abundances of functional microbes, and the activities of key enzymes. Finally, one strategy that could effectively mitigate the adverse impact of high Cd levels on SCFA production was proposed and examined. This work provides insights into Cd-present sludge fermentation systems, and the findings obtained may guide engineers to manipulate sludge treatment systems in the future.

Xu, X-J, Chen, C, Wang, A-J, Ni, B-J, Guo, W-Q, Yuan, Y, Huang, C, Zhou, X, Wu, D-H, Lee, D-J & Ren, N-Q 2017, 'Mathematical modeling of simultaneous carbon-nitrogen-sulfur removal from industrial wastewater', Journal of Hazardous Materials, vol. 321, pp. 371-381.
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© 2016 Elsevier B.V. A mathematical model of carbon, nitrogen and sulfur removal (C-N-S) from industrial wastewater was constructed considering the interactions of sulfate-reducing bacteria (SRB), sulfide-oxidizing bacteria (SOB), nitrate-reducing bacteria (NRB), facultative bacteria (FB), and methane producing archaea (MPA). For the kinetic network, the bioconversion of C-N by heterotrophic denitrifiers (NO3− → NO2− → N2), and that of C-S by SRB (SO42− → S2−) and SOB (S2− → S0) was proposed and calibrated based on batch experimental data. The model closely predicted the profiles of nitrate, nitrite, sulfate, sulfide, lactate, acetate, methane and oxygen under both anaerobic and micro-aerobic conditions. The best-fit kinetic parameters had small 95% confidence regions with mean values approximately at the center. The model was further validated using independent data sets generated under different operating conditions. This work was the first successful mathematical modeling of simultaneous C-N-S removal from industrial wastewater and more importantly, the proposed model was proven feasible to simulate other relevant processes, such as sulfate-reducing, sulfide-oxidizing process (SR-SO) and denitrifying sulfide removal (DSR) process. The model developed is expected to enhance our ability to predict the treatment of carbon-nitrogen-sulfur contaminated industrial wastewater.

Xu, Y, Radjenovic, J, Yuan, Z & Ni, B-J 2017, 'Biodegradation of atenolol by an enriched nitrifying sludge: Products and pathways', Chemical Engineering Journal, vol. 312, pp. 351-359.
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© 2016 Elsevier B.V. Biodegradation of β-blocker atenolol was investigated using an enriched nitrifying culture at controlled ammonium concentration and without ammonium addition. Analysis of the kinetics and structural elucidation of biodegradation products showed that atenolol biodegradation was found to be linked to the activity of nitrifying bacteria in the presence of ammonium. Atenolol was degraded cometabolically by ammonia-oxidizing bacteria (AOB), likely due to a broad substrate range of ammonia monooxygenase (AMO). Four products were formed during atenolol biodegradation with ammonia oxidation, including P267 (atenolol acid) and three new products P117 (1-isopropylamino-2-propanol), P167 (1-amino-3-phenoxy-2-propanol), and an unknown product P227 with a nominal molecular mass of 227. In comparison, only P267 and P227 were identified during atenolol biodegradation without ammonia oxidation. Follow-up experiments using atenolol acid as the parent compound indicated the formation of products P117, P167 and P227 in the presence of ammonium. Based on the products identified, a tentative biodegradation pathway of atenolol is suggested, which involves two steps independent of the presence of ammonium: i) microbial amide-bond hydrolysis to carboxyl group and formation of P267 (atenolol acid) and ii) a possible formation of P227 with its unidentified structure and other two cometabolically induced reactions: iii) breakage of ether bond in the alkyl side chain and formation of P117 and iv) a minor pathway through N-dealkylation and loss of acetamide moiety from the aromatic ring, yielding P167. This study provided an important insight regarding the biotransformation pathways under different metabolic conditions.

Xu, Y, Yuan, Z & Ni, B-J 2017, 'Biotransformation of acyclovir by an enriched nitrifying culture', Chemosphere, vol. 170, pp. 25-32.
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© 2016 Elsevier Ltd This work evaluates the biodegradation of the antiviral drug acyclovir by an enriched nitrifying culture during ammonia oxidation and without the addition of ammonium. The study on kinetics was accompanied with the structural elucidation of biotransformation products through batch biodegradation experiments at two different initial levels of acyclovir (15 mg L−1 and 15 μg L−1). The pseudo first order kinetic studies of acyclovir in the presence of ammonium indicated the higher degradation rates under higher ammonia oxidation rates than those constant degradation rates in the absence of ammonium. The positive correlation was found between acyclovir degradation rate and ammonia oxidation rate, confirming the cometabolism of acyclovir by the enriched nitrifying culture in the presence of ammonium. Formation of the product carboxy-acyclovir (P239) indicated the main biotransformation pathway was aerobic oxidation of the terminal hydroxyl group, which was independent on the metabolic type (i.e. cometabolism or metabolism). This enzyme-linked reaction might be catalyzed by monooxygenase from ammonia oxidizing bacteria or heterotrophs. The formation of carboxy-acyclovir was demonstrated to be irrelevant to the acyclovir concentrations applied, indicating the revealed biotransformation pathway might be the dominant removal pathway of acyclovir in wastewater treatment.

Xu, Y, Yuan, Z & Ni, B-J 2017, 'Impact of Ammonium Availability on Atenolol Biotransformation during Nitrification', ACS Sustainable Chemistry & Engineering, vol. 5, no. 8, pp. 7137-7144.
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© 2017 American Chemical Society. The impact of ammonium availability on atenolol biotransformation at an environmentally relevant level of 15 μgL-1 by enriched nitrifying cultures was investigated in terms of atenolol degradation kinetics and biotransformation product formation dynamics. Different concentrations of growth substrate ammonium (0, 25, and 50 mg-NL-1) were applied constantly during batch experiments. The results suggested the higher ammonium concentrations led to lower atenolol removal rates probably due to the substrate competition between ammonium and atenolol. The formation of the biotransformation product atenolol acid was positively related to the ammonium oxidation activity, resulting in a higher amount at the end of experiments at higher ammonium concentrations. Linear correlations between ammonia oxidation rate and atenolol degradation rate at ammonium levels of 25 and 50 mg-NL-1 suggested the cometabolism of atenolol by ammonia oxidizing bacteria (AOB) in the presence of ammonium. The biotransformation reaction, i.e., hydroxylation on amide group to carboxylic group, could be catalyzed by the nonspecific ammonia monooxygenase (AMO) of AOB. Comparison between atenolol degradation at ammonium levels of 0 and 50 mg-NL-1 demonstrated the formation of atenolol acid was independent of the ammonium availability. This work might give further indication of how to prevent pharmaceuticals from entering into the environment.

Yang, S, Phan, HV, Bustamante, H, Guo, W, Ngo, HH & Nghiem, LD 2017, 'Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening', Bioresource Technology, vol. 234, pp. 439-447.
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Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening.

Yao, M, Woo, Y, Tijing, L, Cesarini, C & Shon, H 2017, 'Improving Nanofiber Membrane Characteristics and Membrane Distillation Performance of Heat-Pressed Membranes via Annealing Post-Treatment', Applied Sciences, vol. 7, no. 1, pp. 78-78.
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© 2017 by the authors. Electrospun membranes are gaining interest for use in membrane distillation (MD) dueto their high porosity and interconnected pore structure however, they are still susceptible towetting during MD operation because of their relatively low liquid entry pressure (LEP). In thisstudy, post-treatment had been applied to improve the LEP, as well as its permeation and saltrejection efficiency. The post-treatment included two continuous procedures: heat-pressing andannealing. In this study, annealing was applied on the membranes that had been heat-pressed.It was found that annealing improved the MD performance as the average flux reached 35 L/m2hor LMH (>10% improvement of the ones without annealing) while still maintaining 99.99% saltrejection. Further tests on LEP, contact angle, and pore size distribution explain the improvementdue to annealing well. Fourier transform infrared spectroscopy and X-ray diffraction analysesof the membranes showed that there was an increase in the crystallinity of the polyvinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) membrane also, peaks indicating the α phase ofpolyvinylidene fluoride (PVDF) became noticeable after annealing, indicating some βand amorphousstates of polymer were converted into the α phase. The changes were favorable for membranedistillation as the non-polar α phase of PVDF reduces the dipolar attraction force between themembrane and water molecules, and the increase in crystallinity would result in higher thermalstability. The present results indicate the positive effect of the heat-press followed by an annealingpost-treatment on the membrane characteristics and MD performance.

Ye, Y, Ngo, HH, Guo, W, Liu, Y, Li, J, Liu, Y, Zhang, X & Jia, H 2017, 'Insight into chemical phosphate recovery from municipal wastewater', Science of The Total Environment, vol. 576, pp. 159-171.
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© 2016 Elsevier B.V. Phosphate plays an irreplaceable role in the production of fertilizers. However, its finite availability may not be enough to satisfy increasing demands for the fertilizer production worldwide. In this scenario, phosphate recovery can effectively alleviate this problem. Municipal wastewater has received high priority to recover phosphate because its quantity is considerable. Therefore, phosphate recovery from municipal wastewater can bring many benefits such as relieving the burden of increasing production of fertilizers and reduction in occurrence of eutrophication caused by the excessive concentration of phosphate in the released effluent. The chemical processes are the most widely applied in phosphate recovery in municipal wastewater treatment because they are highly stable and efficient, and simple to operate. This paper compares chemical technologies for phosphate recovery from municipal wastewater. As phosphate in the influent is transferred to the liquid and sludge phases, a technical overview of chemical phosphate recovery in both phases is presented with reference to mechanism, efficiency and the main governing parameters. Moreover, an analysis on their applications at plant-scale is also presented. The properties of recovered phosphate and its impact on crops and plants are also assessed with a discussion on the economic feasibility of the technologies.

Young, C, Salunkhe, RR, Alshehri, SM, Ahamad, T, Huang, Z, Henzie, J & Yamauchi, Y 2017, 'High energy density supercapacitors composed of nickel cobalt oxide nanosheets on nanoporous carbon nanoarchitectures', Journal of Materials Chemistry A, vol. 5, no. 23, pp. 11834-11839.
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This work demonstrates a simple approach to the development of NiCo₂O₄ and nanoporous carbon composites for high-performance supercapacitor application.

Zahid, R, Hassan, MBH, Varman, M, Mufti, RA, Kalam, MA, Zulkifli, NWBM & Gulzar, M 2017, 'A Review on Effects of Lubricant Formulations on Tribological Performance and Boundary Lubrication Mechanisms of Non-Doped DLC/DLC Contacts', Critical Reviews in Solid State and Materials Sciences, vol. 42, no. 4, pp. 267-294.
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Zhang, B, Song, X, Nghiem, LD, Li, G & Luo, W 2017, 'Osmotic membrane bioreactors for wastewater reuse: Performance comparison between cellulose triacetate and polyamide thin film composite membranes', Journal of Membrane Science, vol. 539, pp. 383-391.
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© 2017 Elsevier B.V. This study compared the performance of the asymmetric cellulose triacetate (CTA) and polyamide thin film composite (TFC) forward osmosis (FO) membranes in an osmotic membrane bioreactor (OMBR). A reverse osmosis (RO) system was integrated with OMBR to regenerate the draw solution and produce clean water. Results show that the TFC membrane exhibited a higher initial water flux but more dramatic flux decline compared to the CTA membrane when they were used for OMBR. The CTA and TFC membranes also resulted in discernible difference in salinity build-up in the bioreactor and thus biomass characteristics during OMBR operation. All 30 trace organic contaminants (TrOCs) selected in this study were effectively removed by the OMBR-RO hybrid system regardless of the FO membrane type. Compared to the CTA membrane, the TFC membrane contributed more significantly toward the removal of hydrophilic and biologically persistent compounds and thus reduced their accumulation in the draw solution during OMBR-RO operation. In addition, CTA and TFC FO membranes also resulted in considerable differences in TrOC residuals in the sludge during OMBR operation.

Zhang, C, Guo, J, Lian, J, Lu, C, Ngo, HH, Guo, W, Song, Y & Guo, Y 2017, 'Characteristics of electron transport chain and affecting factors for thiosulfate-driven perchlorate reduction', Chemosphere, vol. 185, pp. 539-547.
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The mechanism for perchlorate reduction was investigated using thiosulfate-driven (T-driven) perchlorate reduction bacteria. The influences of various environmental conditions on perchlorate reduction, including pH, temperature and electron acceptors were examined. The maximum perchlorate removal rate was observed at pH 7.5 and 40 °C. Perchlorate reduction was delayed due to the coexistence of perchlorate-chlorate and perchlorate-nitrate. The mechanism of the T-driven perchlorate reduction electron transport chain (ETC) was also investigated by utilizing different inhibitors. The results were as follows: firstly, the NADH dehydrogenase was not involved in the ETC; secondly, the FAD dehydrogenase and quinone loop participated in the ETC; and thirdly, cytochrome oxidase was the main pathway in the ETC. Meanwhile, microbial consortium structure analysis indicated that Sulfurovum which can oxidize sulfur compounds coupled to the reduction of nitrate or perchlorate was the primary bacterium in the T-driven and sulfur-driven consortium. This study generates a better understanding of the mechanism of T-driven perchlorate reduction.

Zhang, J, Sun, H, Wang, W, Hu, Z, Yin, X, Ngo, HH, Guo, W & Fan, J 2017, 'Enhancement of surface flow constructed wetlands performance at low temperature through seasonal plant collocation', Bioresource Technology, vol. 224, pp. 222-228.
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In the present study, a novel seasonal plant collocation system (SPCS), specifically the Potamogeton crispus and Phragmites australis series system, was investigated to enhance the performance of surface flow constructed wetlands (SFCWs) at low temperature. Results of a year-round experiment showed that SPCS conquered the adverse effect of low temperature and achieved sustainable nutrients removal. In addition, during winter, removal efficiencies of NH4-N, TP, COD, and TN in SPCS were 18.1%, 17.6%, 10.1% and 5.2% higher than that in the control, respectively. P. crispus and P. australis complemented each other in terms of plant growth and plant uptake during the experiment period. Furthermore, it emerged that P. crispus could increase the quantity of ammonia oxidizing bacteria by 10.2%, due to its high oxygen enrichment ability. It is suggested that seasonal plant collocation has a promising future in SFCWs of areas being affected by climate change, e.g. northern China.

Zhang, X, Song, Z, Guo, W, Lu, Y, Qi, L, Wen, H & Ngo, HH 2017, 'Behavior of nitrogen removal in an aerobic sponge based moving bed biofilm reactor', Bioresource Technology, vol. 245, no. PART A, pp. 1282-1285.
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© 2017 Elsevier Ltd This study aims to investigate the behavior of nitrogen removal in an aerobic sponge based moving bed biofilm reactor by evaluating nitrification and denitrification rates of sponge biocarriers from three aerobic moving bed biofilm reactors (MBBRs) with filling ratios of 10% (R-10), 20% (R-20) and 30% (R-30). Results showed that the highest removal efficiencies of total nitrogen in three reactors were 84.5% (R-10), 93.6% (R-20) and 95.3% (R-30). Correspondingly, simultaneous nitrification and denitrification rate (SND) was 90.9%, 97.6% and 100%, respectively. Although R-20 had the highest attached-growth biomass (AGB) per gram of sponge compared to the other two reactors, R-30 showed the maximum ammonium oxidation rate (AOR) (2.1826 ± 0.0717 mg NH 4 + -N/g AGB/h) and denitrification rate (DNR) (5.0852 ± 0.0891 mg NO 3 − -N/g AGB/h), followed by R-20 and R-10. These results indicated AOR, DNR and AGB were affected by the filling ratio under the same operation mode.

Zhao, H, Cao, Z, Liu, X, Zhan, Y, Zhang, J, Xiao, X, Yang, Y, Zhou, J & Xu, J 2017, 'Seasonal variation, flux estimation, and source analysis of dissolved emerging organic contaminants in the Yangtze Estuary, China', Marine Pollution Bulletin, vol. 125, no. 1-2, pp. 208-215.
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The occurrence and seasonal variation of 24 dissolved emerging organic contaminants in the Yangtze Estuary were studied, including 12 non-antibiotic pharmaceuticals, seven sulfonamides, two macrolides and three chloramphenicols. Sulfadiazine, erythromycin, thiamphenicol and paracetamol were the primary contaminants in sulfonamides, macrolides, chloramphenicols and non-antibiotic pharmaceutical groups, respectively. Compared to the concentrations at Datong, chloramphenicols at Xuliujing were significantly higher in autumn and winter, while macrolides were lower in spring. Based on the flux estimation, approximately 37.1 tons of sulfonamides, 17.4 tons of macrolides, 79.2 tons of chloramphenicols and 14.1 tons of non-antibiotic pharmaceuticals were discharged into the Yangtze Estuary from June 2013 to May 2014. However, the total flux from the Huangpu River only represented 5% of the total. The pharmaceutical sources were speculated on by analyzing the seasonal variations in pharmaceutical concentrations and fluxes at various sites. Both environmental and social factors might affect the fluxes.

Zhao, J, Gui, L, Wang, Q, Liu, Y, Wang, D, Ni, B-J, Li, X, Xu, R, Zeng, G & Yang, Q 2017, 'Aged refuse enhances anaerobic digestion of waste activated sludge', Water Research, vol. 123, pp. 724-733.
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In this work, a low-cost alternative approach (i.e., adding aged refuse (AR) into waste activated sludge) to significantly enhance anaerobic digestion of sludge was reported. Experimental results showed that with the addition dosage of AR increasing from 0 to 400 mg/g dry sludge soluble chemical oxygen demand (COD) increased from 1150 to 5240 mg/L at the digestion time of 5 d, while the maximal production of volatile fatty acids (VFA) increased from 82.6 to 183.9 mg COD/g volatile suspended solids. Although further increase of AR addition decreased the concentrations of both soluble COD and VFA, their contents in these systems with AR addition at any concentration investigated were still higher than those in the blank, which resulted in higher methane yields in these systems. Mechanism studies revealed that pertinent addition of AR promoted solubilization, hydrolysis, and acidogenesis processes and did not affect methanogenesis significantly. It was found that varieties of enzymes and anaerobes in AR were primary reason for the enhancement of anaerobic digestion. Humic substances in AR benefited hydrolysis and acidogenesis but inhibited methanogenesis. The effect of heavy metals in AR on sludge anaerobic digestion was dosage dependent. Sludge anaerobic digestion was enhanced by appropriate amounts of heavy metals but inhibited by excessive amounts of heavy metals. The relative abundances of microorganisms responsible for sludge hydrolysis and acidogenesis were also observed to be improved in the system with AR addition, which was consistent with the performance of anaerobic digestion.

Zhao, Y, Phuntsho, S, Gao, B & Shon, H 2017, 'Polytitanium sulfate (PTS): Coagulation application and Ti species detection', Journal of Environmental Sciences, vol. 52, pp. 250-258.
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© 2016 Interest in the development of inorganic polymerized coagulants is growing; however, there are only limited studies on the synthesis of polytitanium coagulants, which are expected to exhibit improved coagulation efficiency with better floc properties. This study presents the synthesis of polytitanium sulfate (PTS) for potential application in water purification, followed by characterization of PTS flocs and titanium species detection. Stable PTS solutions were successfully synthesized and standard jar tests were conducted to evaluate their coagulation efficiency. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) speciation analysis revealed that a variety of mononuclear and polynuclear complexes were formed in PTS solution, indicating the polymeric nature of the synthesized coagulant. Floc characteristics were studied through on-line monitoring of floc size using a laser diffraction particle size analyzer. Results showed that PTS had a comparable or in some cases even higher organic matter and particulate removal efficiency than Ti(SO4)2. The effluent pH after PTS coagulation significantly improved toward desirable values closer to neutral pH. Properties of flocs formed by PTS were significantly improved in terms of floc size, growth rate and structure. This study showed that PTS could be an efficient and promising coagulant for water purification, with the additional benefit that its coagulated sludge can be used to recover valuable TiO2 nanoparticles for various commercial applications.

Zhao, Y, Sun, Y, Tian, C, Gao, B, Wang, Y, Shon, H & Yang, Y 2017, 'Titanium tetrachloride for silver nanoparticle-humic acid composite contaminant removal in coagulation-ultrafiltration hybrid process: floc property and membrane fouling', Environmental Science and Pollution Research, vol. 24, no. 2, pp. 1757-1768.
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© 2016, Springer-Verlag Berlin Heidelberg. Titanium-based coagulation is expected to achieve both efficient water purification and sludge recycling. This study is the first attempt to use titanium tetrachloride (TiCl4) for silver nanoparticle (AgNP)-humic acid composite contaminant removal in a coagulation-ultrafiltration (C-UF) process, where characterization of flocs and membrane fouling under varied coagulant dose, initial solution pH, and AgNP concentration conditions are the main contents. Results suggested that the TiCl4 achieved high AgNP removal in the form of silver nanoparticle through adsorption and sweep flocculation and simultaneously exerted additional 68.2 % higher dissolved organic carbon removal than Al2(SO4)3. The TiCl4 produced larger and stronger flocs but with weaker recoverability and less compact degree than did Al2(SO4)3. Floc properties were independent of AgNP concentration except floc fractal dimension, which was negatively correlated with AgNP concentration. The TiCl4 precoagulation caused less membrane fouling within wider pH range than Al2(SO4)3 did in the C-UF process. Incorporation of AgNPs during the TiCl4 pretreatment process facilitated the mitigation of membrane fouling, which was, however, negligibly influenced by AgNP concentration in the case of Al2(SO4)3.

Zheng, G, Fang, G, Shankaran, R, Orgun, MA, Zhou, J, Qiao, L & Saleem, K 2017, 'Multiple ECG Fiducial Points-Based Random Binary Sequence Generation for Securing Wireless Body Area Networks', IEEE Journal of Biomedical and Health Informatics, vol. 21, no. 3, pp. 655-663.
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© 2017 IEEE. Generating random binary sequences (BSes) is a fundamental requirement in cryptography. A BS is a sequence of $N$ bits, each bit has a value of 0 or 1. For securing sensors within wireless body area networks (WBANs), electrocardiogram (ECG)-based BS generation methods have been widely investigated in which interpulse intervals (IPIs) from each heartbeat cycle are processed to produce BSes. Using these IPI-based methods to generate a 128-bit BS in real time normally takes around half a minute. In order to improve the time efficiency of such methods, this paper presents an ECG multiple fiducial-points based binary sequence generation (MFBSG) algorithm. The technique of discrete wavelet transforms is employed to detect arrival time of these fiducial points, such as P, Q, R, S, T peaks. Time intervals between them, including RR, RQ, RS, RP, RT intervals, are then calculated based on this arrival time, are used as ECG features to generate random BSes with low latency. According to our analysis on real ECG data, these ECG feature values exhibit the property of randomness and, thus, can be utilized to generate random BSes. Compared with the schemes that solely rely on IPIs to generate BSes, this MFBSG algorithm uses five feature values from one heart beat cycle, can be up to five times faster than the solely IPI-based methods. So, it achieves a design goal of low latency. According to our analysis, the complexity of the algorithm is comparable to that of fast Fourier transforms. These randomly generated ECG BSes can be used as security keys for encryption or authentication in a WBAN system.

Zhou, X, Chen, H, Gao, S-H, Han, S, Tu, R, Wei, W, Cai, C, Liu, P, Jin, W & Wang, Q 2017, 'Effects of particle size of zero-valent iron (ZVI) on peroxydisulfate-ZVI enhanced sludge dewaterability', Korean Journal of Chemical Engineering, vol. 34, no. 10, pp. 2672-2677.
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The advanced oxidization process has proven to be an effective conditioning technique for the improvement of sludge dewaterability. Zero-valent iron (ZVI) is often used as the catalyst of the oxidization process. This study applied ZVI with different particle sizes to the ZVI- peroxydisulfate reactions, and investigated their effects on the improvement of sludge dewaterability. It was found that ZVI particles with smaller sizes (100 and 400 meshes) led to slightly higher enhancement of sludge dewaterability (69.1%–72%) than the larger size particles (20–40 meshes) with the reduction rate of CST by 64%. However, after the treatment, the recycle rate of larger size ZVI particles was obviously higher than the small sizes ZVI particles: 98.3% vs. 87.6–89.7%. Different surface areas of the ZVI particles with different sizes might contribute to the phenomenon. For the small ZVI particles with the sizes of 100 and 400 meshes, no obvious differences of oxidization effects and the improvements of sludge dewaterability were found between them, which might be because an oxide layer could have been formed on the surface of fine ZVI particles and led to agglomeration. According to the economical analysis, the small particles (100 and 400 meshes) of ZVI were more economically favorable for the oxidative conditioning process with ZVI-peroxydisulfate than large ZVI particles (20–40 meshes).

Zhou, X, Jin, W, Chen, H, Chen, C, Han, S, Tu, R, Wei, W, Gao, S-H, Xie, G-J & Wang, Q 2017, 'Enhancing dewaterability of waste activated sludge by combined oxidative conditioning process with zero-valent iron and peroxymonosulfate', Water Science and Technology, vol. 76, no. 9, pp. 2427-2433.
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Abstract The enhancement of sludge dewaterability is of great importance for facilitating the sludge disposal during the operation of wastewater treatment plants. In this study, a novel oxidative conditioning approach was applied to enhance the dewaterability of waste activated sludge by the combination of zero-valent iron (ZVI) and peroxymonosulfate (PMS). It was found that the dewaterability of sludge was significantly improved after the addition of ZVI (0–4 g/g TSS) (TSS: total suspended solids) and PMS (0–1 g/g TSS). The optimal addition amount of ZVI and PMS was 0.25 g/g TSS and 0.1 g/g TSS, respectively, under which the capillary suction time of the sludge was reduced by approximately 50%. The decomposition of sludge flocs could contribute to the improved sludge dewaterability. Economic analysis demonstrated that the proposed conditioning process with ZVI and PMS was more economical than the ZVI + peroxydisulfate and the traditional Fenton conditioning processes.

Zuthi, MFR, Guo, W, Ngo, HH, Nghiem, DL, Hai, FI, Xia, S, Li, J, Li, J & Liu, Y 2017, 'New and practical mathematical model of membrane fouling in an aerobic submerged membrane bioreactor', Bioresource Technology, vol. 238, pp. 86-94.
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This study aimed to develop a practical semi-empirical mathematical model of membrane fouling that accounts for cake formation on the membrane and its pore blocking as the major processes of membrane fouling. In the developed model, the concentration of mixed liquor suspended solid is used as a lumped parameter to describe the formation of cake layer including the biofilm. The new model considers the combined effect of aeration and backwash on the foulants' detachment from the membrane. New exponential coefficients are also included in the model to describe the exponential increase of transmembrane pressure that typically occurs after the initial stage of an MBR operation. The model was validated using experimental data obtained from a lab-scale aerobic sponge-submerged membrane bioreactor (MBR), and the simulation of the model agreed well with the experimental findings.

Aghayarzadeh, M, Khabbaz, H, Fatahi, B & Terzaghi, S 1970, 'Continuum Numerical Modelling Of Dynamic Load Test For Steel Pipe Piles', Proceedings of the International Conference On Advancement of Pile Technology and Pile Case Histories, International Conference On Advancement of Pile Technology and Pile Case Histories, Universitas Katolik Parahyangan, Bali, Indonesia, pp. 1-10.
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In order to estimate the static axial capacity of driven piles, one-dimensional wave equationanalysis was proposed in 1960, in which pile is simulated by a number of masses attached to each other usingelastic springs, sliders and linear viscous dampers to simulate the visco-elasto-plastic response of the soil. Later,the signal matching technique program, CAPWAP, employing this model, was proposed to overcome theshortcomings of the conventional model. The main objective of this paper is to assess capabilities of so-calledcontinuum numerical model in analyzing dynamic pile load test. In this paper, the static and dynamic load testsof an open-ended steel pipe pile driven into dense sand have been simulated using PLAXIS 2D finite elementsoftware. After carrying out a number of numerical analyses the results of numerical simulation have beencompared to static load test results. The capabilities and challenges of the continuum numerical analysis tosimulate dynamic pile testing of steel pipe piles are briefly discussed.

Dang, LC, Khabbaz, H & Fatahi, B 1970, 'An experimental study on engineering behaviour of lime and bagasse fibre reinforced expansive soils', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, the 19th International Conference on Soil Mechanics and Geotechnical Engineering, ISSMGE, Seoul, Republic of Korea, pp. 2497-2500.
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This investigation exhibits a series of laboratory tests conducted to evaluate the influences of bagasse fibre and hydrated lime addition on the engineering properties and swelling behaviour of stabilised expansive soils. Bagasse fibre is industrial waste byproduct left after crushing of sugar-cane for juice extraction, used in this study as a reinforcing component for expansive soil stabilisation. The expansive soils used in this investigation were collected from Queensland, Australia. Varying proportions of randomly distributed bagasse fibre of 0.5%, 1.0%, and 2.0% were added to expansive soil and lime-treated expansive soil to investigate the influences of bagasse fibre on the engineering characteristics of stabilised soil. Results of California bearing capacity (CBR), swell potential and one-dimensional consolidation tests after various curing time are presented and discussed in detail. The findings of this experimental investigation indicate that expansive soil reinforcement, blended with bagasse fibre and lime leads to a significant increase in the compressive strength and the bearing capacity of expansive soil. Meanwhile, the swell potential and compressibility of stabilised expansive soils decreased with increasing lime and bagasse fibre contents.

Dong, Y, Li, D, Fatahi, B, Zhang, X & Khabbaz, H 1970, 'Small-strain shear modulus of soft clay treated with Saccharomyces cerevisiae and cement', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, International Conference on Soil Mechanics and Geotechnical Engineering, pp. 2507-2510.
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Soil stabilisation by means of microorganisms is an emerging and novel technique in geotechnical engineering. On the other hand, cementation, as one of the conventional ground improvement techniques, has been proved to be an effective method to enhance the engineering properties of soils. Hence, it is believed that the combination of these two approaches can be extremely valuable and offer a novel, cost effective, environmentally friendly and practical engineering solution. In this study, the Saccharomyces cerevisiae, a species of yeast, has been selected owing to abundance and production cost to conduct the experiment in order to investigate its influence on the shear wave velocity and the small-strain shear modulus of cement stabilised clays using bender element test. It is observed that an appropriate amount of Saccharomyces cerevisiae can adequately improve the stiffness of soft clays treated with cement and microorganisms in long term.

Ho, L, Li, D, Fatahi, B & Khabbaz, H 1970, 'Analytical solution to one-dimensional consolidation in unsaturated soil due to time-dependent exponential temperature and external step loading', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, pp. 757-760.
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Recent experimental studies demonstrate that temperature changes may significantly influence the deformation of unsaturated soils. Thus, there is an essential need to develop a predictive framework for the unsaturated consolidation capturing non-isothermal effects. This paper introduces analytical solutions to predict the one-dimensional (1D) consolidation of unsaturated soil deposit while incorporating the time-dependent exponential temperature variation. The one-way drainage boundary system and the uniform initial condition are adopted for the mathematical derivation. In this study, governing equations under the non-isothermal condition are first obtained. Then, Fourier sine series and the Laplace transform technique are used to solve these governing equations and obtain the final solutions. This study highlights the combined effects of time-dependent exponential temperature and an external step loading on the excess pore pressures at various depths. It is predicted that the effects of exponential temperature on the dissipation process would be much attenuated at a lower depth.

Huang, B, Fatahi, B & Khabbaz, H 1970, 'Influence of Underground Opening with Stiff Lining on Seismic Response of Buildings', International Conference on Geomechanics and Geoenvironmental Engineering, International Conference on Geomechanics and Geoenvironmental Engineering, Science, Technology and Management Crest 12 Boyer Pl, Minto, New South Wales 2565, Sydney, Australia, Sydney, pp. 125-131.
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In this study, the influence of an underground opening at different depths on seismic performance of a 15-storey moment resisting building subjected to the 1995 Kobe earthquake is investigated. The numerical model consists of a superstructure, soil medium, and an underground opening, all simulated using finite element method in time domain considering soil nonlinearity and soil-structure interaction. The results are presented in terms of foundation rocking angle, distribution of maximum shear force developed in the structure, maximum lateral deflection as well as inter-storey drifts of the building. The results indicate that the underground opening has a notable influence on seismic response of the building. Particularly, the maximum foundation rocking angle is reduced with the presence of the underground opening with stiff concrete lining and the reduction is more significant when the underground opening is constructed at a lower depth. In addition, for a shallower underground opening, as the foundation rocking decreases, seismic energy dissipation is reduced, which in turn, causes more seismic energy transmitted to the structure and consequently larger shear forces are developed in the structure, which reveals the importance of consideration of underground structure in the seismic design of superstructures. Moreover, according to the results, the building constructed above a shallow underground opening experiences relatively smaller lateral displacement and inter-storey drifts subjected to earthquake excitation.

Huang, Y, Hong, G & Zhou, J 1970, 'Numerical Modelling of Ethanol Direct Injection (EDI) Sprays of a Multi-Hole Injector under Non-Evaporating, Transition and Flash-Boiling Conditions', SAE Technical Paper Series, International Powertrains, Fuels & Lubricants Meeting, SAE International.
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Copyright © 2017 SAE International. Ethanol direct injection (EDI) has great potential in facilitating the downsizing technologies in spark ignition engines due to its strong anti-knock ability. The fuel temperature may vary widely from non-evaporating to flash-boiling sprays in real engine conditions. In this study, a CFD spray model was developed in the ANSYS Fluent environment, which was capable to simulate the EDI spray and evaporation characteristics under non-evaporating, transition and flash-boiling conditions. The turbulence was modelled by the realizable k-μ model. The Rinzic heterogeneous nucleation model was applied to simulate the primary breakup droplet size at the nozzle exit. The secondary breakup process was modelled by the Taylor Analogy Breakup model. The evaporation process was modelled by the Convection/Diffusion Controlled Model. The droplet distortion and drag, collision and droplet-wall interaction were also included. The spray model was verified against the spray experimental results in a constant volume chamber. The developed spray model well simulated the EDI spray evolution and evaporation processes under non-evaporating, transition and flash-boiling conditions. The simulation results showed that the non-evaporating spray's characteristics were similar to those of the normal-evaporating spray in terms of spray structure and spray tip penetration. The spray plumes converged towards the middle one with the increase of fuel temperature and finally collapsed completely when the spray superheat degree was higher than 9 K. This was caused by the increased ambient air speed and stronger vortices entrained by the spray jet, and additionally by the significantly reduced droplet size. The EDI spray could be considered as non-evaporating when the fuel temperature was lower than 325 K at 1 bar. The evaporation rate increased slightly with the fuel temperature increased from 275 to 360 K, but significantly from 360 to 400 K. Although it re...

Law, Y, Swa Thi, S, Chen, XM, Nguyen, TQN, Seviour, TW, Williams, RBH, Ni, B & Wuertz, S 1970, 'The Start-up of Mainstream Anammox Process Is Limited Only by Nitrite Supply', Frontiers in Wastewater Treatment and Modelling FICWTM 2017, Frontiers International Conference on Wastewater Treatment, Springer International Publishing, Palermo, Italy, pp. 18-21.
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In this study, we investigated start-up of an Anammox bioprocess from a secondary activated sludge seed fed primary effluent from a domestic used water reclamation plant (WRP). To test the hypothesis that an anammox-enriched sludge could still be achieved under such conditions given enough nitrite and ammonium, nitrite was supplemented at a molar ratio of 2:1 to ammonium. Anammox activity was observed within 50 d of operation and the relative abundance of Anammox bacteria increased from <0.1% gradually up to 4% after 100 d of operation, concomitant with complete ammonium removal. Despite consumption of chemical oxygen demand (COD) by heterotrophic denitrifiers, the Anammox biomass continued to accumulate up to 20% of relative abundance, contributing to biofilm and granule formation in the reactor. Thus, a high influent COD concentration is not inhibitory to the start-up of an Anammox system as long as sufficient nitrite is provided.

Lodi, F, Bodisco, T, Surawski, N, Brown, RJ & Yousef, Y 1970, 'Modelling the effects of ethanol fumigation on engine performance and emissions in a six-cylinder, common rail diesel engine', 11th Asia-Pacific Conference on Combustion, ASPACC 2017, Asia-Pacific Conference on Combustion.
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This paper describes a one-dimensional thermodynamic model developed using AVL BOOST with the objective of analysing the performance, combustion parameters and NOx emissions of a Euro III, six-cylinder turbocharged Cummins diesel engine. The model was validated against experimental data obtained from the same engine run at a constant speed of 2000 rpm at varying load conditions (full, three quarter (3Q) and half load) using low sulphur diesel fuel (D100), as well as fumigated ethanol at 10% (D90), 20% (D80) and 30% (D70) substitutions (by energy). The results for D100, D90, D80 and D70 were found to be in good agreement with the experimental data. The percentage variation for engine performance parameters such as: brake power (BP), indicated power (IP), indicated torque (IT) and mean effective pressure (MEP) for D100 have been found to be approximately in the range of -5% to 1.5% for all loads, whereas, the fuel energy variation was only 0.33% for all loads. With increasing ethanol fumigation, a rise in peak pressure of the cycle, more rapid initial heat release rate and a reduction in the NOx emissions were observed in this study.

Mofijur, M, Rasul, MG & Hassan, NMS 1970, 'Effect of butanol additive on the performance and emission of Australian macadamia biodiesel fuel in a diesel engine', 2017 2nd International Conference Sustainable and Renewable Energy Engineering (ICSREE), 2017 2nd International Conference Sustainable and Renewable Energy Engineering (ICSREE), IEEE, Hiroshima, JAPAN, pp. 33-37.
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Ngoc, TP, Li, D, Fatahi, B & Khabbaz, H 1970, 'A review on the influence of degree of saturation on small strain shear modulus of unsaturated soils', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, International Conference on Soil Mechanics and Geotechnical Engineering, ISSMGE, Seoul, Korea, pp. 1225-1228.
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Small-strain shear modulus (Gmax) is an important parameter in the analysis and design of structures resting on liquefiable soils, particularly under dynamic loads such as earthquakes. In real condition, soil layers near the ground surface consistently undergo variation of degree of saturation (Sr) due to the change of weather or loading-unloading processes that lead to the variation of Gmax. To date, this area has received limited attention and still encounters difficulties in evaluating the influence of Sr on Gmax as well as capturing the effect of hysteresis on water retention behaviour. This study concentrates on the relationship between Sr and Gmax based on available experimental data in literature. The results of the analysis show that Sr plays an important role in the magnitude of Gmax for both cohesionless and cohesive unsaturated soils, while it has a greater influence on the latter. In order to predict Gmax for cohesive soils within the full range of degree of saturation, apart from the influence of Sr on the contribution of matric suction (ym), the influence of Sr on the contribution of plastic fines, salt concentration and van der Waals attraction should be additionally included.

Nguyen, HH, Khabbaz, H, Fatahi, B & Hsi, J 1970, 'Effects of installing controlled modulus columns on previously installed columns', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, the 19th International Conference on Soil Mechanics and Geotechnical Engineering, Seoul, South Korea, pp. 2611-2614.
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Controlled modulus columns (CMC) ground improvement technique is an attractive geotechnical solution for modification of soft soils. This technique uses a displacement auger during column installation, aiming to reduce the construction cost and disposal of excavated materials. However, lateral and vertical soil movement induced by the installation process may pose potential risks to the adjacent previously installed columns. Only a handful of studies have been attempted in quantifying such effects. This paper presents the results of a numerical investigation on the effects of CMC installation sequence on the already installed columns using the three-dimensional finite difference software package FLAC3D. The results indicate that the installation sequence should be taken into account in the design process to minimise any adverse effects of installing new CMCs on the existing columns.

Sharbaf, M, Ghafoori, N & Dumitru, N 1970, 'Geogrid in paved and unpaved road systems: A review of mechanisms and design mehods', Bearing Capacity of Roads, Railways and Airfields - Proceedings of the 10th International Conference on the Bearing Capacity of Roads, Railways and Airfields, BCRRA 2017, International Conference on the Bearing Capacity of Roads, Railways and Airfields, CRC Press, Athens, Greece, pp. 1161-1168.
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© 2017 Taylor & Francis Group, London. This study has focused on the effect of using Lime (L) from 1.5% to 6.25%; Bagasse Ash (BA) between 6% and 25% and combination of BA-L reached up to 25% on the consolidation characteristic of expansive after the swelling pressure has been determined. The results indicated that the swelling pressure was reduced with increasing BA or L. Furthermore, the results were improved when BA was added to soil treated with L. The swelling pressure of untreated soil decreased from 80 kPa (untreated soil) to 7 kPa (treated with 25% BA-L). In consolidation tests, the pre-consolidation stress has been developed from 180 kPa with untreated soil to 290 kPa with 6.25% lime and 350 kPa when 18.75% BA was added to soil-6.25% L. Furthermore, better results were ascertained when soft clay stabilized with 25% BA-L in comparison with compacted virgin soft clay samples. In addition, the compression indices, and swelling indices decreased 97% and 56%, respectively.

Sirivivatnanon, V, Khabbaz, H & Ayton, G 1970, '“Performance-based Specification of sand for skid resistance of concrete pavements”, ASCP 4th Concrete Pavement Conference, 2017.', ASCP 4th Concrete Pavement Conference, 2017, ASCP 4th Concrete Pavement Conference, 2017.

Sun, WJ, Liu, C, Wei, G, Sun, DA, Wei, ZF, Liu, SQ & Fatahi, B 1970, 'Effect of sand content on undrained behaviour of GMZ bentonite-sand mixtures', Proceedings - IACMAG 2017, 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, pp. 1497-1503.
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The hydro-mechanical behaviour was studied by carrying out the constant water content triaxial tests on Gaomiaozi (GMZ) bentonite-sand mixtures with sand content of 70% and 50%, and the stress-strain relationship, deformation and pore water pressure under undrained shear state were obtained, together with the changes of the initial suction, compressibility, suction and strength with the sand content in mixtures. Moreover, the control mechanism was analyzed in microscopic level. The research provides the experimental basis to establish the hydro-mechanical model for unsaturated expansive soils under undrained state, and can be available for reference in proportional optimization design in bentonite based materials used in deep geological disposal system and waste landfills projects.

Surawski, N, Van, TC, Ristovski, Z, Cong, NL, Lan, HN, Yuan, CSJ, Rahman, SMA, Hossain, FM, Guo, Y, Milic, A, Rainey, T, Garaniya, V & Brown, RJ 1970, 'Effects of sulphur and vanadium contents in diesel fuel on engine performance and emissions: Principal component analysis (PCA)', 11th Asia-Pacific Conference on Combustion, ASPACC 2017.
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Marine diesel engines using Heavy Fuel Oil (HFO) produce emissions of toxic compounds that have a negative impact on the environment and human health. A very limited number of on-board ship emission measurement studies have been undertaken due their logistical and regulatory complexity. An alternative way to investigate some issues relating to HFO fuels is by the use of a proxy fuel for HFO in a laboratory based diesel engine. Sulphur (S) and vanadium (V) are two elements of particular interest in HFO because of their relationship to particle formation and corrosive salt properties, respectively. An experimental engine campaign has been conducted on a heavy duty high speed six-cylinder turbocharged and after-cooled diesel engine with a common rail injection system. Principal Component Analysis has been applied in this study to investigate the relationships between: (i) measured engine performance and emissions variables and (ii) fuel S and V content and engine load.

Xu, R, Fatahi, B & Li, D 1970, 'Effects of Soil Stiffness on Seismic Response of Buildings Considering Soil-Pile-Structure Interaction', The 19th International Conference on Soil Mechanics and Geotechnical Engineering, Seoul, Korea.

Xu, R, Li, D & Fatahi, B 1970, 'Effects of soil stiffness on seismic response of buildings considering soil-pile-structure interaction', ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering, 19th International Conference on Soil Mechanics and Geotechnical Engineering (19ICSMGE), Seoul, South Korea, pp. 1619-1622.
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In this study, a fifteen-storey moment resisting building sitting on an end-bearing pile foundation in soil socketed in rock is selected in conjunction with four values of shear wave velocity. Effects of corresponding shear strength are studied through numerical modelling using finite difference software FLAC3D. Fully nonlinear dynamic analysis under the influence of Northridge earthquake is performed. The results indicate that soil plasticity should be taken into account while conducting dynamic analysis considering soil-pile-structure interaction. However, the dynamic response of the structure regarding base shear, foundation slab rotation, pile lateral deflection and structure lateral deflection is sensitive to the effect of shear strength with the increase in shear wave velocity and corresponding shear modulus. Also, the results show that the dynamic response of structures sitting on end-bearing pile foundations depends not only on base shear attracted by the superstructure but also on the foundation slab rotation. Therefore, to perform realistic seismic analysis and to conduct reasonable seismic design of mid-rise building resting on end-bearing pile foundations, the consideration of foundation slab rotation is essential.

Yeganeh, N, Fatahi, B & Terzaghi, S 1970, 'Effects of shear wave velocity profile of soil on seismic response of high rise buildings', Proceedings - IACMAG 2017, 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, International Conference of the International Association for Computer Methods and Advances in Geomechanics, International Association for Computer Methods and Advances in Geomechanics (IACMAG), Wuhan, China, pp. 920-928.
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There is, nowadays, a conspicuous demand for the high rise buildings in the high-density dwellings of the urban areas; in consequence, harnessing the whiz-bang numerical simulations plus conducting the rigorous experimental studies so as to design and construct such prodigious structures would be essential. Thus, the appropriate parameters for modeling the structure and the soil medium in the Soil-Structure Interaction (SSI) system should be selected. The soil-structure interaction is referred to the process in which the soil response is told on by the structure motion whilst the latter is affected by the soil motion. The current research zeroed in on the soil shear wave velocity and its influence on the superstructure performance. Invoking the weighted average shear wave velocity with the aim of calculating the soil shear modulus, which is closely related to the strength and deformation characteristics of the soil, has been a hotly debated issue since the aforesaid parameter was posited by a plethora of codes and regulations to obtain the soil site classification required for the earthquake design. To that end, the numerical model, having two assorted profiles associated with the shear wave velocity, namely, the in situ non-uniform profile (Case A) and the equivalent uniform profile (Case B), was built by means of FLAC3D, capable of analyzing the complex interaction issues via the direct method whereby the entire system of the structure-foundation-soil is modeled and analyzed in one single step. To put it in a nutshell, employing the weighted average shear wave velocity for the entire soil mass in parsing of the 3D seismic soil-structure interaction problems would be accused for ending up with somewhat unreliable results, e.g., underestimated drift ratio and building deformation, which might be the culprit of the damage to the building and possibly the death of the residents residing in the earthquake-prone zones.

Zhang, X, Fatahi, B, Khabbaz, H & Zhang, H 1970, 'Investigating effects of fracture density on stress-strain behaviour of jointed rocks using discrete element method', Proceedings - IACMAG 2017, 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, The 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics, Wuhan, China, pp. 726-732.
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Adopting discrete element method (DEM) to simulate the behaviour of jointed rocks is becoming more common due to discrete nature of the medium. In this study, the discontinuum based software PFC3D has been employed to analyse the effects of fracture density on the rock mass unconfined compressive strength of jointed rocks. The flat-joint model allowing partial damages at the contact surfaces has been utilised to simulate the mechanical behaviour of the rock, while the smooth-joint contact model has been employed to simulate the sliding effect of fractures. Indeed, 18 jointed rock specimens with different fracture density values ranging from 5 m2/m3 to 240 m2/m3 have been simulated in this study. Via comparing the stress-strain behaviour and failure mechanisms of the jointed rocks subjected to unconfined compression, the impact of fracture density has been investigated. It can be concluded that the rock mass unconfined compressive strength decreased significantly when the fracture density increased to 60 m2/m3 for the simulated medium strength marble, and then reduced gradually and eventually the rock mass unconfined compressive strength of the fractured rock dropped below 5 MPa. The modulus of elasticity also reduced with increasing fracture density.

Bouman, HA, Platt, T, Doblin, M, Figueiras, FG, Gudmudsson, K, Gudfinnsson, HG, Huang, B, Hickman, A, Hiscock, M, Jackson, T, Lutz, VA, Mélin, F, Rey, F, Pepin, P, Segura, V, Tilstone, GH, van Dongen-Vogels, V & Sathyendranath, S 2017, 'Photosynthesis-irradiance parameters of marine phytoplankton: synthesis of a global data set', Copernicus GmbH.
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Abstract. The photosynthetic performance of marine phytoplankton varies in response to a variety of factors, environmental and taxonomic. One of the aims of the MArine primary Production: model Parameters from Space (MAPPS) project of the European Space Agency is to assemble a global database of photosynthesis-irradiance (P-E) parameters from a range of oceanographic regimes as an aid to examining the basin-scale variability in the photophysiological response of marine phytoplankton and to use this information to improve the assignment of P-E parameters in the estimation of global marine primary production using satellite data. The MAPPS P-E Database, which consists of over 5000 P-E experiments, provides information on the spatio-temporal variability in the two P-E parameters (the assimilation number, PmB, and the initial slope, αB, where the superscripts B indicate normalisation to concentration of chlorophyll) that are fundamental inputs for models (satellite-based and otherwise) of marine primary production that use chlorophyll as the state variable. Quality-control measures consisted of removing samples with abnormally-high parameter values and flags were added to denote whether the spectral quality of the incubator lamp was used to calculate a broad-band value of αB. The MAPPS database provides a photophysiological dataset that is unprecedented in number of observations and in spatial coverage. The database would be useful to a variety of research communities, including marine ecologists, biogeochemical modellers, remote-sensing scientists and algal physiologists. The compiled data are available at https://doi.org/10.1594/PANGAEA.874087 (Bouman et al., 2017).

Kelleway, JJ, Saintilan, N, Macreadie, PI, Baldock, JA & Ralph, PJ 2017, 'Sediment and carbon accumulation vary among vegetation assemblages in a coastal saltmarsh', Copernicus GmbH, Copernicus GmbH.
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Abstract. Coastal saltmarshes are dynamic, intertidal ecosystems which are increasingly being recognised for their contributions to ecosystem services, including carbon (C) accumulation and storage. The survival of saltmarshes and their capacity to store C under rising sea levels, however, is partially reliant upon surface sedimentation rates and influenced by a combination of physical and biological factors. In this study, we use several complementary methods to assess short-term (days) deposition and medium-term (months) accretion dynamics within three saltmarsh vegetation types common throughout southeast (SE) Australia. We found that surface accretion varies among vegetation assemblages, with medium-term (19 month) bulk accretion rates in the upper marsh rush (Juncus) assemblage (1.74 ± 0.13 mm y−1) consistently in excess of estimated local sea level rise (1.15 mm y−1). Accretion was lower and less consistent in both the succulent (Sarcocornia) (0.78 ± 0.18 mm y−1) and grass (Sporobolus) (0.88 ± 0.22 mm y−1) assemblages located lower in the tidal frame. Short-term (6 d) experiments showed deposition within Juncus plots to be dominated by autochthonous organic inputs with C deposition rates ranging from 0.41 ± 0.15 g C cm−2 y−1 (neap tidal period) to 0.87 ± 0.16 g C cm−2 y−1 (spring tidal period), while minerogenic inputs and lower C deposition dominated Sarcocornia (0.03 ± 0.01 to 0.23 ± 0.03 g C cm−2 y−1) and Sporobolus (0.06 ± 0.01 to 0.15 ± 0.03 g C cm−2 y−1) assemblages. Elemental (C : N), isotopic (δ13C), mid infrared (MIR) and 13C NMR analyses revealed little difference in either the source or character of materials being deposited among neap versus spring tidal periods. Instead, these analyses point to substantial redistribution of materials within the Sarcocornia and Sporobolus assemblages, compared to high retention and preservation of organic inputs in the Juncus assemblage. By combining medium-term accretion quantification with short-term d...

Kumar, M & Ralph, P 2017, 'Systems Biology of Marine Ecosystems', Springer International Publishing, pp. 1-351.
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© Springer International Publishing AG 2017. This book describes the latest advances in systems biology in four plant-based marine ecosystems: seaweeds, seagrasses, microalgae, and corals. Marine organisms that inhabit the oceanic environment experience a diverse range of environmental fluctuations, anthropogenic stress, and threats from invasive species and pathogens. System biology integrates physiology, genomics, transcriptomics, proteomics, and metabolomics into numerical models and is emerging as an important approach to elucidate the functional adaptations of marine organisms to adverse environmental conditions. This book focuses on how ecophysiology, omics platforms, their integration (a systems biology perspective), and next generation sequencing tools are being used to address the stress response of marine seaweeds, seagrasses, corals, marine microbe diversity, and micro-and macroalgae/corals-bacterial interactions to global climate change and anthropogenic activities. The contents of the book are of special interest to graduate and postgraduate marine biology students and marine biology researchers, particularly those interested in marine ecology, stress physiology of marine macrophytes/corals/phytoplankton, and environmental microbiology. This book would also be of interest to marine engineers engaged in the management and conservation of our valuable marine resources.

Roobavannan, M, van Emmerik, THM, Elshafei, Y, Kandasamy, J, Sanderson, M, Vigneswaran, S, Pande, S & Sivapalan, M 2017, 'Norms and values in socio-hydrological models', Copernicus GmbH.
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