Abdal-hay, A, Tijing, LD & Lim, JK 2013, 'Characterization of the surface biocompatibility of an electrospun nylon 6/CaP nanofiber scaffold using osteoblasts', Chemical Engineering Journal, vol. 215-216, pp. 57-64.
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The purpose of this research is to improve the biocompatibility of bone tissue engineering scaffolds using a one-step electrospinning process. Calcium phosphate (CaP) was coated on the surface of nylon 6 (N6) nanofibers to form an ultrathin layer, thereby increasing surface roughness and wettability of the N6 nanofiber membrane in order to further improve implant tissue integration. The morphology, composition, chemical interaction bonding and mechanical properties of CaP-coated N6 nanofibers were characterized. The wettability of the scaffold was measured in terms of the water contact angle, and the results indicated that N6 fibers coated with an ultrathin layer of CaP exhibited an excellent surface wettability (water contact angle = 0°). Mechanical testing revealed higher properties of coated CaP layers compared to a plain N6 mat. The biological response induced by the surface modifications of N6 fibers was evaluated by in vitro cell culture with MC3T3-E1 osteoblasts cells. It was found that CaP-coated N6 nanofibrous matrices definitely favored cell proliferation, with the efficiency dependent upon the coating technique. A combination of a nanoscale fibrous structure and a CaP coating could mimic the structure, composition and function of bone tissues
Abedin, MJ, Masjuki, HH, Kalam, MA, Sanjid, A, Rahman, SMA & Masum, BM 2013, 'Energy balance of internal combustion engines using alternative fuels', Renewable and Sustainable Energy Reviews, vol. 26, pp. 20-33.
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Afshar-Mazandaran, R & Khabbaz, H 2013, 'Evaluating the Bearing Capacity of a Soil Layer Overlying Rigid Substratum Using a Modified Failure Mechanism Based on Limit State Analysis', ADVANCES IN CIVIL AND INDUSTRIAL ENGINEERING, PTS 1-4, vol. 353-356, pp. 806-814.
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The bearing capacity of shallow foundations resting on a soil layer with a finite depth over bedrock has been studied for years by many investigators. Farzaneh et al (2010) introduced a rigorous bearing capacity analysis based on the upper bound state theorem, using a log-spiral surface algorithm. This paper presents a thorough evaluation of this collapse mechanism and subsequently, a modified failure mechanism is introduced. The collapse mechanism consists of rigid blocks under combined rotational and transitional movements. The effects of the loading parameters on bearing capacity results are then discussed. The findings of this study are compared with the original limit state mechanism as well as previously published solutions, emphasising the accuracy and efficiency of the modified mechanisms. Furthermore, parametric studies are carried out to evaluate the ultimate bearing capacity of shallow foundations resting on a restricted soil, layer using the proposed mechanism. Design tables are finally presented for practical use in geotechnical engineering. © (2013) Trans Tech Pudlications, Switzerland.
Altaee, A 2013, 'Theoretical study on feed water designs to reverse osmosis pressure vessel', Desalination, vol. 326, pp. 1-9.
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Scale fouling and power consumption are one of the most important parameters in reverse osmosis (RO) desalination. To reduce scale problems in RO, single or central feeds to the pressure vessel were suggested instead of using end feed. In this paper Reverse Osmosis System Analysis (ROSA) software was used to simulate the differences between single, central and end feed designs. The effect of feed Silt Density Index (SDI) and number of the RO elements in the pressure vessel were investigated here. Feed SDIs 5, 3, and 1 were considered in this paper. To study the effect of the numbers of RO elements, 6 RO and 8 RO elements per pressure vessel were simulated. The simulation results showed that the power consumption in the end feed design was lower than in the single and central feed designs. The simulation results showed that Langelier Silt Index (LSI) and Stiff & Davis Stability Index (SDSI) were lower in the single than central feed design which in turn was lower than in the end feed design. These results indicated that although the power consumption in the single and central feed designs was higher than in the end feed design; the former designs were more efficient in rescuing the RO scale problems. © 2013 Elsevier B.V.
Altaee, A, Mabrouk, A & Bourouni, K 2013, 'A novel Forward osmosis membrane pretreatment of seawater for thermal desalination processes', Desalination, vol. 326, pp. 19-29.
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Altaee, A, Mabrouk, A & Bourouni, K 2013, 'Corrigendum to “A novel forward osmosis membrane pretreatment of seawater for thermal desalination processes” [Desalination 326 (2013) 19–29]', Desalination, vol. 329, pp. 115-115.
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Alturki, AA, McDonald, JA, Khan, SJ, Price, WE, Nghiem, LD & Elimelech, M 2013, 'Removal of trace organic contaminants by the forward osmosis process', Separation and Purification Technology, vol. 103, pp. 258-266.
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Amarjargal, A, Jiang, Z, Tijing, LD, Park, C-H, Im, I-T & Kim, CS 2013, 'Nanosheet-based α-Fe2O3 hierarchical structure decorated with TiO2 nanospheres via a simple one-pot route: Magnetically recyclable photocatalysts', Journal of Alloys and Compounds, vol. 580, pp. 143-147.
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Amarjargal, A, Tijing, LD, Im, I-T & Kim, CS 2013, 'Simultaneous preparation of Ag/Fe3O4 core–shell nanocomposites with enhanced magnetic moment and strong antibacterial and catalytic properties', Chemical Engineering Journal, vol. 226, pp. 243-254.
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In this study, core–shell Ag/Fe3O4 nanocomposites have been successfully prepared by modified co-precipitation route followed by facile hydrothermal treatment in one-pot synthesis under various (Ag(NH3)2+) ion concentrations without adding any reducing agents. A single crystal Ag core and polycrystallized Fe3O4 shell nanostructures could be obtained when high amount of AgNO3 precursor are used in the presence of Fe2+ ions source, i.e., ferrous salt alone. A mechanism leading to the formation of such morphologies was proposed and samples were characterized with several analytical techniques including field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FT-IR) spectroscopy. Significant increase of saturation magnetic moment was observed for the Ag/Fe3O4 nanocomposite. The results showed enhanced magnetic moment and strong catalytic and antibacterial activities of the present Ag/Fe3O4 nanocomposite, demonstrating its importance for potential application in water treatment and biomedical application, with the ability of subsequent removal by means of an external magnetic field.
Amarjargal, A, Tijing, LD, Park, C-H, Im, I-T & Kim, CS 2013, 'Controlled assembly of superparamagnetic iron oxide nanoparticles on electrospun PU nanofibrous membrane: A novel heat-generating substrate for magnetic hyperthermia application', European Polymer Journal, vol. 49, no. 12, pp. 3796-3805.
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A facile method of fabricating novel heat-generating membranes composed of electrospun polyurethane (PU) nanofibers decorated with superparamagnetic iron oxide nanoparticles (NPs) is reported. Electrospinning was used to produce polymeric nanofibrous matrix, whereas polyol immersion technique allowed in situ assembly of well-dispersed Fe3O4 NPs on the nanofibrous membranes without any surfactant, and without sensitizing and stabilizing reagent. The assembly phenomena can be explained by the hydrogen-bonding interactions between the amide groups in the PU matrix and the hydroxyl groups capped on the surface of the Fe3O4 NPs. The prepared nanocomposite fibers showed acceptable magnetization value of 33.12 emu/g, after measuring the magnetic hysteresis loops using SQUID. Moreover, the inductive heating property of electrospun magnetic nanofibrous membranes under an alternating current (AC) magnetic field was investigated. We observed a progressive increase in the heating rate with the increase in the amount of magnetic Fe3O4 NPs in/on the membranes. The present electrospun magnetic nanofibrous membrane may be a potential candidate as a novel heat-generating substrate for localized hyperthermia cancer therapy. © 2013 Elsevier Ltd. All rights reserved.
Amarjargal, A, Tijing, LD, Ruelo, MTG, Park, C-H, Pant, HR, Vista IV, FP, Lee, DH & Kim, CS 2013, 'Inactivation of bacteria in batch suspension by fluidized ceramic tourmaline nanoparticles under oscillating radio frequency electric fields', Ceramics International, vol. 39, no. 2, pp. 2141-2145.
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Here, we investigated the synergistic effect of fluidized ceramic tourmaline nanoparticles (NPs) with oscillating electric fields to the inactivation of Escherichia coli in batch suspension. Different amounts of tourmaline NPs (5–100 mg) were dispersed in bacterial suspension (50 ml) and oscillating radio frequency (RF) electric field was applied at 3 V (equivalent of 1.5 V/cm electric field strength) and at varying frequencies (100 kHz and 1 MHz). The results showed high inactivation efficiency when combining fluidized tourmaline NPs and oscillating electric fields as compared to individual treatments of electric fields or tourmaline NPs only. The results showed 2.5–5-log reduction of viable E. coli concentration depending on the tourmaline concentration, electric field frequency and solution temperature. The present method shows a lot of promise as a novel and low-cost bacterial inactivation technique for water treatment applications.
Anisur, MR, Mahfuz, MH, Kibria, MA, Saidur, R, Metselaar, IHSC & Mahlia, TMI 2013, 'Curbing global warming with phase change materials for energy storage', Renewable and Sustainable Energy Reviews, vol. 18, pp. 23-30.
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Arbab, MI, Masjuki, HH, Varman, M, Kalam, MA, Imtenan, S & Sajjad, H 2013, 'Fuel properties, engine performance and emission characteristic of common biodiesels as a renewable and sustainable source of fuel', Renewable and Sustainable Energy Reviews, vol. 22, pp. 133-147.
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Aryal, R, Beecham, S, Vigneswaran, S, Kandasamy, J & Naidu, R 2013, 'Spatial variation of polycyclic aromatic hydrocarbons and equivalent toxicity in Sydney Harbour, Australia', Journal of Water and Climate Change, vol. 4, no. 4, pp. 364-372.
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Harbour sediments include wash-off from different nearby catchments that have various landuse activities. In this study the spatial variation of polycyclic aromatic hydrocarbons (PAHs) in Sydney Harbour was studied by analysing the sediment. The sediment was collected from 12 locations and 16 PAHs that are prioritized by the United States Environmental Protection Authority were analysed. The concentrations in the sediment were in the range of 54–23,440 ng/g of total PAHs and this varied from location to location. The result suggests that the harbour is contaminated with PAHs from low concentration to very high concentration. Among the total PAHs, approximately 75% were medium to higher molecular weight 4- and 5-ring member PAHs. A toxicity identification evaluation (TEQ) approach using a toxicity equivalency factor (TEF) was applied to assess the sediment toxicity. The TEF was found to be between 22 and 8,277 ng TEQ/g. The TEQ value indicated potential adverse ecological and human health effects in many locations.
Asrul, M, Zulkifli, NWM, Masjuki, HH & Kalam, MA 2013, 'Tribological Properties and Lubricant Mechanism of Nanoparticle in Engine Oil', Procedia Engineering, vol. 68, pp. 320-325.
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Atabani, AE, Badruddin, IA, Mahlia, TMI, Masjuki, HH, Mofijur, M, Lee, KT & Chong, WT 2013, 'Fuel Properties of Croton megalocarpus, Calophyllum inophyllum, and Cocos nucifera (coconut) Methyl Esters and their Performance in a Multicylinder Diesel Engine', Energy Technology, vol. 1, no. 11, pp. 685-694.
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AbstractBiodiesel has been considered recently as a viable alternative to fossil diesel fuels. This study aims to evaluate the potential of biodiesel production from Croton megalocarpus oil and compared it with coconut (Cocos nucifera) and Calophyllum inophyllum methyl esters. The study presents the physical and chemical properties of Croton megalocarpus, Calophyllum inophyllum and coconut methyl esters (CMME, CIME, and COME) together with their 10 and 20 % blends by volume (B10 and B20). This is followed by evaluating their blends in a multicylinder Mitsubishi Pajero diesel engine. It has been found that the properties of all biodiesel and their blends are comparable with ASTM D6751 and ASTM D7467 standards, respectively. Over the entire range of speed, it was found that the B10 and B20 blends of CMME, CIME, and COME result in average reduction in torque and brake power (BP) along with increased brake‐specific fuel consumption (BSFC) compared to pure diesel fuel. With respect to engine emissions, the fuel blends resulted in an average reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions. However, the CMME and COME blends resulted in increased emissions of nitrogen oxides (NO) whereas CIME emits lower NO compared to pure diesel. It is concluded that B10 and B20 biodiesel blends can be used as diesel fuel substitutes without additional modifications.
Atabani, AE, Mahlia, TMI, Anjum Badruddin, I, Masjuki, HH, Chong, WT & Lee, KT 2013, 'Investigation of physical and chemical properties of potential edible and non-edible feedstocks for biodiesel production, a comparative analysis', Renewable and Sustainable Energy Reviews, vol. 21, pp. 749-755.
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Atabani, AE, Mahlia, TMI, Masjuki, HH, Badruddin, IA, Yussof, HW, Chong, WT & Lee, KT 2013, 'A comparative evaluation of physical and chemical properties of biodiesel synthesized from edible and non-edible oils and study on the effect of biodiesel blending', Energy, vol. 58, pp. 296-304.
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Atabani, AE, Silitonga, AS, Ong, HC, Mahlia, TMI, Masjuki, HH, Badruddin, IA & Fayaz, H 2013, 'Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production', Renewable and Sustainable Energy Reviews, vol. 18, pp. 211-245.
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Baird, ME, Ralph, PJ, Rizwi, F, Wild-Allen, K & Steven, ADL 2013, 'A dynamic model of the cellular carbon to chlorophyll ratio applied to a batch culture and a continental shelf ecosystem', LIMNOLOGY AND OCEANOGRAPHY, vol. 58, no. 4, pp. 1215-1226.
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A novel parameterization of the dynamical relationship between cellular carbon (C) and chlorophyll (Chl) is developed using a Chl synthesis term that includes the physiological status of the cell and the effect of packaging of pigments within cells. The geometric derivation highlights the non-linear relationship between Chl content and absorption due to the package effect. When parameterized for a generic 3 mm radius phytoplankton cell, the model reproduces the magnitude and daily variations of C: Chl and C: nitrogen ratios of the diatom Skeletonema costatum in published laboratory experiments. The parameterization is then applied in a three-dimensional biogeochemical model containing three phytoplankton classes in the coastal waters off southeast Tasmania, Australia, which demonstrates the behavior of the dynamic Chl parameterization over a range of light- and nutrient-limiting environments for phytoplankton of different sizes and growth rates. The model produces C: Chl ratios of , 1220 (weight : weight) and , 6080 for phytoplankton communities dominated by fast-growing small and fast-growing large cells, respectively, close to the ratios of 17 and 76 observed at two sampling stations during periods with diatom- and flagellate-dominated communities. Throughout the simulation, community C: Chl ratios generally vary between 12 and 200, which is similar to the range observed globally. In the new parameterization, C: Chl ratios are most influenced by the package effect for light-limited, slow-growing large microalgae, with physiological processes becoming important for smaller, nutrient-limited, fast-growing microalgae.
Bedi, JS, Lester, DW, Fang, YX, Turner, JFC, Zhou, J, Alfadul, SM, Perry, C & Chen, Q 2013, 'Electrospinning of poly(methyl methacrylate) nanofibers in a pump-free process', Journal of Polymer Engineering, vol. 33, no. 5, pp. 453-461.
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AbstractThe effects of processing parameters, including solution concentration, viscosity, nozzle diameter, voltage bias and the nozzle to collector distance, on the morphology and diameters of poly(methyl methacrylate) (PMMA) fibers have been systematically investigated, using a unique pump-free electrospinning method. For PMMA solution concentrations less than the critical entanglement concentration, ce, prolate spheroid-shaped droplets or beads with fibers were formed, whereas at concentrations above ce, good quality bead-free fibers were formed. Quantitative analysis revealed a linear dependence between the solution viscosity and fiber diameter. Larger fiber diameters were achieved by increasing the nozzle diameter and voltage bias. Increasing the bias voltage has the additional effect of broadening the diameter distribution, as a result of splaying and splitting. By contrast, when the strength of the electrical field was reduced by increasing the distance between the nozzle and collector, the overall fiber diameter was reduced.
Cath, TY, Elimelech, M, McCutcheon, JR, McGinnis, RL, Achilli, A, Anastasio, D, Brady, AR, Childress, AE, Farr, IV, Hancock, NT, Lampi, J, Nghiem, LD, Xie, M & Yip, NY 2013, 'Standard Methodology for Evaluating Membrane Performance in Osmotically Driven Membrane Processes', DESALINATION, vol. 312, pp. 31-38.
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Chanan, AP, Vigneswaran, S, Kandasamy, J & Johir, MA 2013, 'Need for a fresh look at phosphorus management in wastewater treatment: Trash to treasure', Sustainable Environment Research, vol. 23, no. 1, pp. 23-31.
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Eutrophication of water bodies is a major, global environmental problem. It is now well understood that its main cause is excessive amounts of nutrients such as phosphorus. Stringent laws were therefore introduced across the world, requiring that the level of the P be significantly reduced. Consequently, the focus for wastewater treatment industry became the elimination of phosphorus in effluent stream. Treatment technologies capable of removing over 90% of phosphorus from wastewater have now been developed. However, these phosphorus removal options are likely to be ineffective in the future. The future would call for a shift to the primary goal of phosphorus removal to 'capturing and reusing' phosphorus. This paper calls for a re-think in developing phosphorus management programs. Discussing Fertigation as step-one in phosphorus reclamation, the paper will further elaborate phosphorus recovery opportunities such as ion-exchange that can be retrofitted to existing wastewater treatment plants.
Chekli, L, Phuntsho, S, Kandasamy, J & Shon, H 2013, 'Assessing the aggregation behaviour of iron oxide nanoparticles by using a multi-method approach.', Technical Proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013, vol. 1, pp. 47-50.
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Iron nanoparticles are becoming increasingly popular for the treatment of contaminated soil and groundwater; however, their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Assessing their stability under environmental conditions is crucial for determining their environmental fate. A multi-method approach (including different size-measurement techniques) was used to thoroughly characterise the behaviour of iron oxide nanoparticles (Fe2O3NPs) under environmentally relevant conditions. Although recent studies have demonstrated the importance of using a multi-method approach when characterising nanoparticles, the majority of current studies continue to use a single-method approach. Discussions and examples to support the need of a multi-method approach to characterise the aggregation of nanoparticles will be presented in this study.
Chekli, L, Phuntsho, S, Roy, M & Shon, HK 2013, 'Characterisation of Fe-oxide nanoparticles coated with humic acid and Suwannee River natural organic matter', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 461, pp. 19-27.
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Iron oxide nanoparticles are becoming increasingly popular for various applications including the treatment of contaminated soil and groundwater; however, their mobility and reactivity in the subsurface environment are significantly affected by their tendency to aggregate. One solution to overcome this issue is to coat the nanoparticles with dissolved organic matter (DOM). The advantages of DOM over conventional surface modifiers are that DOM is naturally abundant in the environment, inexpensive, non-toxic and readily adsorbed onto the surface of metal oxide nanoparticles.In this study, humic acid (HA) and Suwannee River natural organic matter (SRNOM) were tested and compared as surface modifiers for Fe2O3 nanoparticles (NPs). The DOM-coated Fe2O3 NPs were characterised by various analytical methods including: flow field-flow fractionation (FlFFF), high performance size exclusion chromatography (HPSEC) and Fourier transform infrared spectroscopy (FTIR). The stability of the coated NPs was then evaluated by assessing their aggregation and disaggregation behaviour over time.Results showed that both HA and SRNOM were rapidly and readily adsorbed on the surface of Fe2O3 NPs, providing electrosteric stabilisation over a wide range of pH. HPSEC results showed that the higher molecular weight components of DOM were preferentially adsorbed onto the surface of Fe2O3. As SRNOM consists of macromolecules with a higher molecular weight than HA, the measured size of the SRNOM-coated Fe2O3 NPs was 30% larger than the HA-coated Fe2O3 NPs. FTIR results indicated the occurrence of hydrogen bonding arising from electrostatic interaction between the DOM and Fe2O3 NPs. Finally, a stability study showed that after 14days, small agglomerates and aggregates were formed. The HA-coated Fe2O3 NPs formed agglomerates which were easily disaggregated using a vortex mixer, with the coated NPs returning to their initial size. However, SRNOM-coated Fe2O3 NPs were only partially disagg...
Chekli, L, Phuntsho, S, Roy, M, Lombi, E, Donner, E & Shon, HK 2013, 'Assessing the aggregation behaviour of iron oxide nanoparticles under relevant environmental conditions using a multi-method approach', WATER RESEARCH, vol. 47, no. 13, pp. 4585-4599.
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Iron nanoparticles are becoming increasingly popular for the treatment of contaminated soil and groundwater; however, their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Assessing their stability under environmental conditions is crucial for determining their environmental fate. A multi-method approach (including different size-measurement techniques and the DLVO theory) was used to thoroughly characterise the behaviour of iron oxide nanoparticles (Fe2O3NPs) under environmentally relevant conditions. Although recent studies have demonstrated the importance of using a multi-method approach when characterising nanoparticles, the majority of current studies continue to use a single-method approach.Under some soil conditions (i.e. pH 7, 10mM NaCl and 2mM CaCl2) and increasing particle concentration, Fe2O3NPs underwent extensive aggregation to form large aggregates (>1μm). Coating the nanoparticles with dissolved organic matter (DOM) was investigated as an alternative 'green' solution to overcoming the aggregation issue instead of using the more commonly proposed polyelectrolytes. At high concentrations, DOM effectively covered the surface of the Fe2O3NPs, thereby conferring negative surface charge on the particles across a wide range of pH values. This provided electrostatic stabilisation and considerably reduced the particle aggregation effect. DOM-coated Fe2O3NPs also proved to be more stable under high ionic strength conditions. The presence of CaCl2, however, even at low concentrations, induced the aggregation of DOM-coated Fe2O3NPs, mainly via charge neutralisation and bridging. This has significant implications in regards to the reactivity and fate of these materials in the environment. © 2013 Elsevier Ltd.
Chen, Z, Ngo, HH & Guo, W 2013, 'A Critical Review on the End Uses of Recycled Water', CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 43, no. 14, pp. 1446-1516.
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Recycled water provides a viable opportunity to supplement water supplies as well as alleviate environmental loads. The authors examine the sources of recycled water and discusses various end uses. They focus on reviewing the historical development and current status of recycled water on a global scale with containing the evolvement of wastewater treatment technologies, water quality guidelines, and public attitudes. The authors also illustrate typical case studies of recycled water in a number of countries and regions, including Australia, Asia, the United States, Latin America, Europe, the Middle East, and Africa. These pilot studies can be good examples for the future projects. They identify the good prospects of further expansion and exploration of current and new end uses while emphasizing the integrated water planning and management as well as challenging and tasks in the future. © 2013 Copyright Taylor and Francis Group, LLC.
Chen, Z, Ngo, HH & Guo, W 2013, 'Risk Control in Recycled Water Schemes', CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 43, no. 22, pp. 2439-2510.
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Recycled water is becoming one of the indispensable and reliable water resources at present. When it is introduced as an alternative source, risks on human health and the environment become major constraints driving the application and extension of recycled water. The authors examine the sources and associated risks of recycled water and introduce the practical risk control technologies on various end uses. They also review some existing risk assessment models by comparing their strengths and weaknesses toward the good approach of integrated modeling. Some critical suggestions on risk management and communication are made based on the given information. © 2013 Taylor and Francis Group, LLC.
Chen, Z, Ngo, HH, Guo, W & Wang, X 2013, 'Analysis of Sydney's recycled water schemes', FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING, vol. 7, no. 4, pp. 608-615.
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© Higher Education Press and Springer-Verlag Berlin Heidelberg 2012. Recycled water provides a viable opportunity to partially supplement fresh water supplies as well as substantially alleviate environmental loads. Currently, thousands of recycled water schemes have been successfully conducted in a number of countries and Sydney is one of the leading cities, which has made massive effort to apply water reclamation, recycling and reuse. This study aims to make a comprehensive analysis of recycled water schemes in Sydney for a wide range of end uses such as landscape irrigation, industrial process uses and residential uses (e.g., golf course irrigation, industrial cooling water reuse, toilet flushing and clothes washing etc.). For each representative recycled water scheme, this study investigates the involved wastewater treatment technologies, the effluent quality compared with specified guideline values and public attitudes toward different end uses. Based on these obtained data, multi criteria analysis (MCA) in terms of risk, cost-benefit, environmental and social aspects can be performed. Consequently, from the analytical results, the good prospects of further expansion and exploration of current and new end uses were identified toward the integrated water planning and management. The analyses could also help decision makers in making a sound judgment for future recycled water projects.
Chen, Z, Ngo, HH, Guo, W, Wang, XC, Miechel, C, Corby, N, Listowski, A & O'Halloran, K 2013, 'Analysis of social attitude to the new end use of recycled water for household laundry in Australia by the regression models', JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol. 126, no. 1, pp. 79-84.
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Recycled water for household laundry can be regarded as a promising strategy to alleviate the current demand on scarce water supplies. Public acceptability becomes fairly important to ensure the successful establishment and development of this new end use. To address the issue, this study conducted social surveys in two locations of Australia, Port Macquarie and Melbourne, where respondents were asked 17 questions. The regression models provide conclusions about which characteristics are more likely to lead to the acceptance of recycled water from society. Three attitudinal variables (RWAlterDW, Attitude and Cost) and three psychological variables (Odour, Reading and SmallUnit) were found to be the key driving forces behind domestic water reuse behaviour. These findings could drive the future research direction to achieve better public perception of this new end use of recycled water. © 2013 Elsevier Ltd.
Chon, K, Cho, J & Shon, HK 2013, 'A pilot-scale hybrid municipal wastewater reclamation system using combined coagulation and disk filtration, ultrafiltration, and reverse osmosis: Removal of nutrients and micropollutants, and characterization of membrane foulants', Bioresource Technology, vol. 141, no. 1, pp. 109-116.
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A pilot-scale municipal wastewater reclamation system using combined coagulation and disk filtration (CCDF), ultrafiltration (UF), and reverse osmosis (RO) membrane has been built to investigate removal of water contaminants and fouling mitigation. The reclaimed water using the pilot system could meet draft regulations on wastewater reuse of the California Department of Public Health (DOC: 0.5 mgC/L; TN: 5 mgN/L). The removal of micropolluants by the CCDF process and UF could not be evaluated by their MW, Log D, and charge characteristics. However, they were identified as governing factors affecting the removal of micropollutants by the RO. The CCDF process might effectively remove particulate materials capable of contributing to cake layer formation on the UF membrane surfaces but the residual coagulants provided a strong effect on fouling formation of the UF membrane. Thus, hydrophobic fractions of the desorbed UF membrane foulants were higher than those of the desorbed RO membrane foulants.
Chon, K, Cho, J & Shon, HK 2013, 'Fouling characteristics of a membrane bioreactor and nanofiltration hybrid system for municipal wastewater reclamation', Bioresource Technology, vol. 130, pp. 239-247.
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A laboratory-scale membrane bioreactor (MBR) and nanofiltration (NF) hybrid system has been built to investigate effects of changes in characteristics of effluent organic matter by the MBR on fouling characteristics of the NF membranes. Large amounts of polysaccharide-like substances with small molecular weight and strong fluorescence intensity at the excitation wavelength of 230 nm and the emission wavelength of 420 nm were produced by microbial growth in the MBR. These substances had a great influence on fouling formation of the NF membranes. Fouling characteristics of the MBR were governed by both hydrophobic and hydrophilic fractions while hydrophilic fractions were found as major constituents of the desorbed NF membrane foulants. Flux decline rates of the NF membranes were closely associated with differences in their fouling layer compositions, meaning that performances of the NF membranes (i.e., flux decline) could be influenced by the membrane characteristics (i.e., surface zeta potential and contact angle).
Clark, JS, Poore, AGB, Ralph, PJ & Doblin, MA 2013, 'POTENTIAL FOR ADAPTATION IN RESPONSE TO THERMAL STRESS IN AN INTERTIDAL MACROALGA', JOURNAL OF PHYCOLOGY, vol. 49, no. 4, pp. 630-639.
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Understanding responses of marine algae to changing ocean temperatures requires knowledge of the impacts of elevated temperatures and the likelihood of adaptation to thermal stress. The potential for rapid evolution of thermal tolerance is dependent on the levels of heritable genetic variation in response to thermal stress within a population. Here, we use a quantitative genetic breeding design to establish whether there is a heritable variation in thermal sensitivity in two populations of a habitat-forming intertidal macroalga, Hormosira banksii (Turner) Descaisne. Gametes from multiple parents were mixed and growth and photosynthetic performance were measured in the resulting embryos, which were incubated under control and elevated temperature (20°C and 28°C). Embryo growth was reduced at 28°C, but significant interactions between male genotype and temperature in one population indicated the presence of genetic variation in thermal sensitivity. Selection for more tolerant genotypes thus has the ability to result in the evolution of increased thermal tolerance. Furthermore, genetic correlations between embryos grown in the two temperatures were positive, indicating that those genotypes that performed well in elevated temperature also performed well in control temperature. Chlorophyll a fluorescence measurements showed a marked decrease in maximum quantum yield of photosystem II (PSII) under elevated temperature. There was an increase in the proportion of energy directed to photoinhibition (nonregulated nonphotochemical quenching) and a concomitant decrease in energy used to drive photochemistry and xanthophyll cycling (regulated nonphotochemical quenching). However, PSII performance between genotypes was similar, suggesting that thermal sensitivity is related to processes other than photosynthesis. © 2013 Phycological Society of America.
Dafforn, KA, Kelaher, BP, Simpson, SL, Coleman, MA, Hutchings, PA, Clark, GF, Knott, NA, Doblin, MA & Johnston, EL 2013, 'Polychaete Richness and Abundance Enhanced in Anthropogenically Modified Estuaries Despite High Concentrations of Toxic Contaminants', PLOS ONE, vol. 8, no. 9, pp. 1-10.
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Ecological communities are increasingly exposed to multiple chemical and physical stressors, but distinguishing anthropogenic impacts from other environmental drivers remains challenging. Rarely are multiple stressors investigated in replicated studies over large spatial scales (.1000 kms) or supported with manipulations that are necessary to interpret ecological patterns. We measured the composition of sediment infaunal communities in relation to anthropogenic and natural stressors at multiple sites within seven estuaries. We observed increases in the richness and abundance of polychaete worms in heavily modified estuaries with severe metal contamination, but no changes in the diversity or abundance of other taxa. Estuaries in which toxic contaminants were elevated also showed evidence of organic enrichment. We hypothesised that the observed response of polychaetes was not a `positive response to toxic contamination or a reduction in biotic competition, but due to high levels of nutrients in heavily modified estuaries driving productivity in the water column and enriching the sediment over large spatial scales. We deployed defaunated field-collected sediments from the surveyed estuaries in a small scale experiment, but observed no effects of sediment characteristics (toxic or enriching). Furthermore, invertebrate recruitment instead reflected the low diversity and abundance observed during field surveys of this relatively `pristine estuary. This suggests that differences observed in the survey are not a direct consequence of sediment characteristics (even severe metal contamination) but are related to parameters that covary with estuary modification such as enhanced productivity from nutrient inputs and the diversity of the local species pool. This has implications for the interpretation of diversity measures in large-scale monitoring studies in which the observed patterns may be strongly influenced by many factors that covary with anthropogenic modification.
Fam, W, Phuntsho, S, Lee, JH & Shon, HK 2013, 'Performance comparison of thin-film composite forward osmosis membranes', DESALINATION AND WATER TREATMENT, vol. 51, no. 31-33, pp. 6274-6280.
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Forward osmosis (FO) is an emerging low-energy technology. Much effort was given on developing a new membrane material and engineering membrane structure to improve the performance of FO membranes. The performances of two newly developed polyamide-based thin-film composite (TFC) FO membranes were tested and compared with the commercially available cellulose triacetate (CTA) FO membrane. The intrinsic properties of the two TFC FO membranes determined in RO experiments indicate superior performance of the membranes. When tested in FO experiments, TFC membranes delivered consistent results, confirming their outstanding permeability and selectivity properties. The study shows that future studies on membrane fouling will be necessary to have a better understanding of membrane performance and to further optimize membrane properties. © 2013 Copyright Balaban Desalination Publications.
Fan, J, Wang, W, Zhang, B, Guo, Y, Ngo, HH, Guo, W, Zhang, J & Wu, H 2013, 'Nitrogen removal in intermittently aerated vertical flow constructed wetlands: Impact of influent COD/N ratios', BIORESOURCE TECHNOLOGY, vol. 143, no. 1, pp. 461-466.
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The performance response of eight vertical flow constructed wetlands (VFCWs) to different influent COD/N ratios and intermittent aeration in domestic wastewater treatment was investigated. Almost complete nitrification was obtained by intermittent aeration, which well developed alternate anaerobic and aerobic conditions for nitrification and denitrification. Sufficient carbon source supply resulted from influent COD/N ratio of 10 simultaneously obtained high removals of COD (96%), ammonia nitrogen (99%) and total nitrogen (90%) in intermittently aerated VFCWs. In all non-aerated VFCWs, poor nitrification was observed due to oxygen deficiency whilst high COD/N ratios further led to lower COD and nitrogen removal efficiency. The results suggest that intermittent aeration combined with high influent COD/N ratios could achieve high nitrogen removal in VFCWs.
Fan, J, Zhang, B, Zhang, J, Ngo, HH, Guo, W, Liu, F, Guo, Y & Wu, H 2013, 'Intermittent aeration strategy to enhance organics and nitrogen removal in subsurface flow constructed wetlands', BIORESOURCE TECHNOLOGY, vol. 141, no. 1, pp. 117-122.
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In this study, an intermittent-aerated subsurface flow constructed wetland (SFCW) A was set up to assess its performance in decentralized rural sewage treatment. A conventional SFCW B and a subsurface wastewater infiltration system (SWIS C) were also constructed for comparison. Alternate anaerobic and aerobic conditions were well developed by intermittent aeration. High removal of organic pollutants (29.3 g m-2 d-1), ammonium nitrogen (3.5 g m-2 d-1) and total nitrogen (3.3 g m-2 d-1) were obtained simultaneously in SFCW A compared with SFCW B and SWIS C. Fluorescence in situ hybridization analysis proved that the intermittent aeration obviously enhanced the growth of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in SFCW A. These results suggest that intermittent aeration strategy is reliable to enhance the performance of SFCWs in decentralized rural sewage treatment.
Fatahi, B 2013, 'PREDICTING SETTLEMENT OF CHEMICALLY STABILISED LANDFILLS', International Journal of Geomate, vol. 5, no. 2, pp. 700-705.
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This paper presents the findings of numerical analyses to predict the vertical and horizontal displacements of closed landfills under surcharge load with and without treatment by chemical admixtures. The finite element program, PLAXIS, has been used to evaluate the settlement of a landfill model. The soft soil creep model is used for this analysis. Five layers of solid waste are considered for the landfill to evaluate the effect of depth of stabilisation on settlement of landfill model. Treated and untreated municipal solid waste (MSW) parameters are obtained from the results of an extensive laboratory program performed on MSW samples in this research. The settlement of the landfill model 10 and 20 years after applying the surcharge load for different fly ash-quicklime contents and various depths of improvement is estimated. Results indicate that treatment of MSW reduces the vertical displacement of the landfill model under surcharge load significantly. This reduction is more with higher depths of improvement. The finite element results have been validated based on results of triaxial tests conducted in the laboratory on the treated municipal solid waste. © 2013, International Journal of GEOMATE.
Fatahi, B & Khabbaz, H 2013, 'Influence of fly ash and quicklime addition on behaviour of municipal solid wastes', JOURNAL OF SOILS AND SEDIMENTS, vol. 13, no. 7, pp. 1201-1212.
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Purpose: Many closed municipal solid waste landfill sites are near urban areas and there are high expectations to improve geotechnical properties of these sites for re-development. Construction on closed landfill sites is generally a challenging task due to complex behaviour of creep, settlement, high amount of moisture content and weak shear strength of waste. This study presents the experimental results for the use of fly ash and quicklime in improvement of the geotechnical properties of municipal solid wastes (MSW). Materials and methods: The waste materials were collected from a closed landfill in the southwest of Sydney. The samples were prepared by integrating MSW with a mixture of fly ash-quicklime with a ratio of 3:1 in percentages of 5, 10, 15 and 20 of fly ash by dry weight of the MSW. An array of experimental tests has been conducted on treated and untreated MSW samples including sieve analysis, Atterberg limits, compaction and consolidated-drained triaxial tests. Results and discussion: Results of this investigation showed a significant improvement in geotechnical properties of MSW. It has been found that by increasing fly ash-quicklime admixtures from 0 to 26.7 % (0 to 20 % fly ash), the internal friction angle increased from 29 to 39° and the cohesion intercept increased from 11 to 30 kPa. Under an effective confining pressure of 300 kPa, the peak strength, the brittleness index and the Young's modulus at failure increased from 600 to 1,150 kPa, 0.13 to 0.35 and 5.5 MPa to 28 MPa, by addition of 26.7 % fly ash-quicklime admixture, respectively. Moreover, the compression and the secondary compression indices decreased from 0.33 to 0.23 and 0.052 to 0.033, respectively. Conclusions: It is found that the chemical stabilisation effectively increases the compressive strength, the shear strength parameters, the stiffness and the brittleness index whilst decreases the settlement of the MSW layer. It will be beneficial and effective in re-developm...
Fatahi, B & Khabbaz, H 2013, 'Optimising the pattern of semi-rigid columns to improve performance of rail tracks overlying soft soil formation', Australian Geomechanics Journal, vol. 48, no. 3, pp. 89-97.
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With Australia facing a rapid increase in population in the next 30 years, the government is being proactive in handling the forecasted growth. The release of 2010 Metropolitan Transport Plan by the New South Wales (NSW) Government shows that the State of NSW will see an increase in commuter travel by rail. The NSW rail system is one of the most complex networks in the world and due to population growth, the network will require further expansion with construction of new railway lines partly on weak and marginal ground and will also require more frequent train running on existing lines. This study seeks to identify the effectiveness of semi-rigid inclusion ground improvement techniques particularly stone columns and deep soil mixing in controlling settlement of soft soils when placed under the dead loads of the rail structure and the large live loads of freight trains. The employed numerical study assesses the relationship between the column position in the track cross section and the overall settlement of the ballasted rail formation. The numerical results show that the overall settlement of the track reduces significantly with the use of columns close to the centre of the track and not just under the rail. In addition, application of one layer of geogrids between sub-ballast and sub-grade assists to reduce the maximum settlement of track decreasing the future maintenance costs.
Fatahi, B & Khabbaz, H 2013, 'PREDICTING SETTLEMENT OF CHEMICALLY STABILISED LANDFILLS', INTERNATIONAL JOURNAL OF GEOMATE, vol. 5, no. 10, pp. 700-705.
Fatahi, B, Fatahi, B, Le, TM & Khabbaz, H 2013, 'Small-strain properties of soft clay treated with fibre and cement', GEOSYNTHETICS INTERNATIONAL, vol. 20, no. 4, pp. 286-300.
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To improve the dynamic properties of soft soil, the cement treatment technique combined with fibre reinforcement can be employed. In this study, the effects of two types of fibres (polypropylene and recycled carpet) on the hardening process and small-strain properties of cement-treated kaolinite and bentonite clays are investigated. Cement-treated clay specimens were prepared using cement contents of 5%, 10% and 15% by weight of dry soil for the kaolinite samples, and 30%, 40% and 50% for the bentonite samples. To investigate and understand the influence of different fibre types and contents, three different percentages of fibre content were adopted: 0.1%, 0.2% and 0.5% polypropylene fibres, and 0.5%, 0.75% and 1% carpet fibres. The results of bender element tests on 126 cylindrical samples of cement-treated clay with various cement and fibre contents were analysed to discern the relationships between fibre and cement content and the small-strain mechanical properties, including the shear wave velocity and maximum small-strain shear modulus of the treated soil. The influence of fibres and cement contents on the hardening time of treated soil has also been investigated. © 2013 Thomas Telford Ltd.
Fatahi, B, Le, TM, Fatahi, B & Khabbaz, H 2013, 'Shrinkage Properties of Soft Clay Treated with Cement and Geofibers', Geotechnical and Geological Engineering, vol. 31, no. 5, pp. 1421-1435.
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In this study, effects of two types of geofibers, namely polypropylene and recycled carpet, on three dimensional shrinkage properties of cement treated kaolinite and bentonite clays are investigated. Cement treated clay specimens were prepared with cement contents of 5, 10, and 15 % by weight of dry soil for kaolinite samples, and 30, 40 and 50 % for bentonite samples. To investigate and understand the influence of different fiber types and contents, three different percentages of fiber content (i.e. 0.1, 0.2 and 0.5 % polypropylene fibers; and 0.5, 0.75 and 1 % carpet fibers) were adopted. The results of shrinkage tests on 126 cylindrical samples of cement treated clay with various cement and fiber contents were analysed to understand the relationships between these parameters and the shrinkage percentage of treated soil. Results of this study indicate that combination of cement and fiber is effective in reducing the volume change of clayey soils undergoing drying process. In the applied ranges of cement and fiber contents, the influence of cement addition on the shrinkage reduction is more significant than the addition of fibers for the treated kaolinite. However, addition of fibers in curtailing the shrinkage of bentonite clay is more significant than the cement addition. © 2013 Springer Science+Business Media Dordrecht.
Fatahi, B, Le, TM, Le, MQ & Khabbaz, H 2013, 'Soil creep effects on ground lateral deformation and pore water pressure under embankments', Geomechanics and Geoengineering, vol. 8, no. 2, pp. 107-124.
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Analysing the behaviour of the soft ground under embankments is a challenging task and is of significant interest to practising geotechnical engineers. This paper revisits a well known case study of an embankment of Boston Blue Clay, which was thoroughly instrumented and measured with piezometers, settlement rods and inclinometers over a long time period during and after construction. The soil parameters were very comprehensively collected by both in situ and laboratory tests in several major test programs. The behaviour of the ground considering the modified Cam-Clay model including and excluding soil creep is simulated using finite element method. The analysed data are verified with field measurements and a parametric study is conducted to evaluate the influence of creep index on excess pore water pressures generated and the displacement of the ground under the embankment. It is observed that both horizontal displacements and excess pore water pressures of the ground under the embankment increased by the creep index. Thus effects of soil creep should be precisely considered in predicting the ground performance under embankments. © 2013 Copyright Taylor and Francis Group, LLC.
Fauzi, H, Metselaar, HSC, Mahlia, TMI, Silakhori, M & Nur, H 2013, 'Phase change material: Optimizing the thermal properties and thermal conductivity of myristic acid/palmitic acid eutectic mixture with acid-based surfactants', Applied Thermal Engineering, vol. 60, no. 1-2, pp. 261-265.
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Fu, Q, Halim, A, Kim, J, Scofield, JMP, Gurr, PA, Kentish, SE & Qiao, GG 2013, 'Highly permeable membrane materials for CO2 capture', Journal of Materials Chemistry A, vol. 1, no. 44, pp. 13769-13769.
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Fujioka, T, Khan, SJ, McDonald, JA, Henderson, RK, Poussade, Y, Drewes, JE & Nghiem, LD 2013, 'Effects of membrane fouling on N-nitrosamine rejection by nanofiltration and reverse osmosis membranes', Journal of Membrane Science, vol. 427, pp. 311-319.
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Fujioka, T, Khan, SJ, McDonald, JA, Roux, A, Poussade, Y, Drewes, JE & Nghiem, LD 2013, 'N-nitrosamine rejection by nanofiltration and reverse osmosis membranes: The importance of membrane characteristics', Desalination, vol. 316, pp. 67-75.
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Fujioka, T, Khan, SJ, McDonald, JA, Roux, A, Poussade, Y, Drewes, JE & Nghiem, LD 2013, 'N-nitrosamine rejection by reverse osmosis membranes: A full-scale study', Water Research, vol. 47, no. 16, pp. 6141-6148.
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Fujioka, T, Oshima, N, Suzuki, R, Khan, SJ, Roux, A, Poussade, Y, Drewes, JE & Nghiem, LD 2013, 'Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer', Separation and Purification Technology, vol. 116, pp. 426-432.
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Gobler, CJ, Lobanov, AV, Tang, Y-Z, Turanov, AA, Zhang, Y, Doblin, M, Taylor, GT, Sanudo-Wilhelmy, SA, Grigoriev, IV & Gladyshev, VN 2013, 'The central role of selenium in the biochemistry and ecology of the harmful pelagophyte, Aureococcus anophagefferens', ISME JOURNAL, vol. 7, no. 7, pp. 1333-1343.
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The trace element selenium (Se) is required for the biosynthesis of selenocysteine (Sec), the 21st amino acid in the genetic code, but its role in the ecology of harmful algal blooms (HABs) is unknown. Here, we examined the role of Se in the biology and ecology of the harmful pelagophyte, Aureococcus anophagefferens, through cell culture, genomic analyses and ecosystem studies. This organism has the largest and the most diverse selenoproteome identified to date that consisted of at least 59 selenoproteins, including known eukaryotic selenoproteins, selenoproteins previously only detected in bacteria, and novel selenoproteins. The A. anophagefferens selenoproteome was dominated by the thioredoxin fold proteins and oxidoreductase functions were assigned to the majority of detected selenoproteins. Insertion of Sec in these proteins was supported by a unique Sec insertion sequence. Se was required for the growth of A. anophagefferens as cultures grew maximally at nanomolar Se concentrations. In a coastal ecosystem, dissolved Se concentrations were elevated before and after A. anophagefferens blooms, but were reduced by 495% during the peak of blooms to 0.05 nM. Consistent with this pattern, enrichment of seawater with selenite before and after a bloom did not affect the growth of A. anophagefferens, but enrichment during the peak of the bloom significantly increased population growth rates. These findings demonstrate that Se inventories, which can be anthropogenically enriched, can support proliferation of HABs, such as A. anophagefferens through its synthesis of a large arsenal of Se-dependent oxidoreductases that fine-tune cellular redox homeostasis.
Guadie, A, Xia, S, Zhang, Z, Guo, W, Ngo, HH & Hermanowicz, SW 2013, 'Simultaneous removal of phosphorus and nitrogen from sewage using a novel combo system of fluidized bed reactor-membrane bioreactor (FBR-MBR)', BIORESOURCE TECHNOLOGY, vol. 149, no. 1, pp. 276-285.
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A FBRMBR combo system was designed as a novel approach for simultaneous phosphorus and nitrogen removal from sewage. The combo system was evaluated more than 7 months under variable pH (7.5-9.5), hydraulic retention times (HRT = 2-10 h), intermittent aeration cycles (IAC) (on/off = 60/60-15/45 min) and sludge retention times (SRT = 1060 d). Prior recovery of phosphorus as struvite in the FBR enhanced nitrogen and COD removal efficiency in MBR. Under optimum operating conditions (pH = 9, HRT = 6 h and IAC = 45/15 min), PO43-P, NH4-N and COD removal efficiencies were 92.6 ± 4.2, 98.7 ± 1.2 and 99.3 ± 0.5%, respectively. Stable mixed liquor suspended solid concentration (3.0-5.0 g/L); enhanced nitrificationdenitrification activity (78-92%) and reduced transmembrane pressure were also achieved. Compared to soluble microbial products, extracellular polymeric substances (EPS) showed strong correlation with fast membrane fouling. Among EPS components, carbohydrate rather than protein was associated with membrane fouling. Except HRT, all parameters considered (pH, IAC, SRT) showed a significant effect on removal efficiency.
Gustafsson, MSM, Baird, ME & Ralph, PJ 2013, 'The interchangeability of autotrophic and heterotrophic nitrogen sources in Scleractinian coral symbiotic relationships: A numerical study', ECOLOGICAL MODELLING, vol. 250, pp. 183-194.
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The success of corals in tropical oligotrophic waters depends largely on their symbiotic relationship with the dinoflagellate algae residing in their tissues. Understanding the dynamics of this symbiosis is essential to predict how corals respond to environmental stressors, such as changes in nutrients availability, water temperatures and irradiance. This study presents a numerical model of the symbiotic relationship between a heterotrophic coral (cnidarian) host and autotrophic symbiotic dinoflagellates, including the major metabolic and physical functions of the system, under non-bleaching conditions. The coral acquires nitrogen (N) through two processes, uptake of dissolved inorganic nitrogen (VH DIN) and heterotrophic feeding (ZN). Numerical experiments were used to highlight the importance of these different sources of N for coral survival and growth. The model was analyzed for four external nutrient supply scenarios, using combinations of two VH DIN rates (high and low) and two ZN rates (high and low), and for a range of light levels. The model outputs showed the importance of the algae symbionts to the coral host as a source of both N and C when the feeding rate was limited, with heterotrophic feeding providing only 14% of the N needed to sustain the host biomass for the low ZN + high VH DIN scenario. In contrast, with no light or low light, conditions under which the symbiont population dies, the host was able to survive if ZN was high. Living inside the host the symbiont population thrived as long as there was enough light, as well as, DIN and DIC in the host tissues, independent of whether N was supplied as ZN or VH DIN. Translocation and recycling of nutrient were two of the most important features of this model, emphasizing why it is essential to resolve host and symbiont in a coral model. The model highlights that the interchangeability of N sources, and the ability to exchange and recycle nutrients in the host-symbiont system, is the key to coral su...
Hong, Y, Burford, MA, Ralph, PJ, Udy, JW & Doblin, MA 2013, 'The cyanobacterium Cylindrospermopsis raciborskii is facilitated by copepod selective grazing', HARMFUL ALGAE, vol. 29, no. 1, pp. 14-21.
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Blooms of the toxin-producing cyanobacterium Cylindrospermopsis raciborskii occur in tropical and subtropical lakes during spring-summer but the mechanisms behind bloom formation are unclear. This study tests the hypothesis that C. raciborskii accumulations in freshwater systems are facilitated by selective copepod grazing. Prey selection was examined in a series of experiments with C. raciborskii and the green alga, Chlamydomonas reinhardtii, as well as within natural phytoplankton assemblages. Clearance rates of the copepod Boeckella sp. on a C. raciborskii diet were 24 times lower than that of a common cladoceran Ceriodaphnia sp. when both grazers had prey choice. More C. raciborskii was cleared by Boeckella sp. when in mixed natural phytoplankton assemblages, but the clearance rate declined when nutrient replete C. reinhardtii was added, demonstrating that when alternate high quality algae were present, so did C. raciborskii consumption. The clearance rates of Boeckella sp. on two toxic C. raciborskii strains were significantly lower than on a non-toxic strain, and on C. raciborskii with low cellular P content. When we tested the grazing preference of a copepod dominated mixed zooplankton community on C. raciborskii during the early bloom period, clearance rates were relatively low (0.050.20 ml individual-1 h-1), and decreased significantly as the proportion of C. raciborskii increased above 5%. These results suggest that C. raciborskii persistence could be promoted by copepods preferentially grazing on other algae, with significant loss of top-down control as C. raciborskii abundance increases.
Hossain, MD, Ngo, H & Guo, W 2013, 'Introductory of Microsoft Excel SOLVER function-Spreadsheet method for isotherm and kinetics modelling of metals biosorption in water and wastewater', Journal of Water Sustainability, vol. 3, no. 4, pp. 223-237.
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This paper aims to introduce a simple method to run a complicated non-linear analysis of isotherm and kinetics models for metals biosorption based on input functions of spreadsheets. A robust method is demonstrated here to exploit the `SOLVER function available in Microsoft (MS) Excel spreadsheet. It is more economic and user friendly than specialized computer programmes. In this study, an iterative method was proposed to produce the optimal goodness of fit between experimental data and predicted data. This was described the implementing method of a set of real data (garden grass as biosorbent) and the predicted results were compared with linear analysis and MATLAB analysis. The R2 values found from MS Excel spreadsheet were 0.995, 0.999 and 0.996 while being 0.997, 1.000 and 0.999 by MATLAB for copper, lead and cadmium adsorption, respectively onto garden grass. The prediction of maximum adsorption, qm by excel (59.336, 63.663 and 42.310 mg/g) were very similar to MATLAB (59.889, 63.509 and 41.560 mg/g). The predictions of kinetics parameters were also close to MATLAB analysis. Hence, the MS Excel Spreadsheet method could be a handy tool for biosorption models.
Huang, Z, Eagles, M, Porter, S, Sorte, EG, Billet, B, Corey, RL, Conradi, MS & Zhao, J-C 2013, 'Thermolysis and solid state NMR studies of NaB3H8, NH3B3H7, and NH4B3H8', Dalton Trans., vol. 42, no. 3, pp. 701-708.
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Huang, Z, Lingam, HK, Chen, X, Porter, S, Du, A, Woodard, PM, Shore, SG & Zhao, J-C 2013, 'Synthesis, structural analysis, and thermal decomposition studies of [(NH3)2BH2]B3H8', RSC Advances, vol. 3, no. 20, pp. 7460-7460.
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Hussan, MJ, Hassan, MH, Kalam, MA & Memon, LA 2013, 'Tailoring key fuel properties of diesel–biodiesel–ethanol blends for diesel engine', Journal of Cleaner Production, vol. 51, pp. 118-125.
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Imran, A, Masjuki, HH, Kalam, MA, Varman, M, Hasmelidin, M, Mahmud, KAHA, Shahir, SA & Habibullah, M 2013, 'Study of Friction and Wear Characteristic of Jatropha Oil Blended Lube Oil', Procedia Engineering, vol. 68, pp. 178-185.
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Imran, A, Varman, M, Masjuki, HH & Kalam, MA 2013, 'Review on alcohol fumigation on diesel engine: A viable alternative dual fuel technology for satisfactory engine performance and reduction of environment concerning emission', Renewable and Sustainable Energy Reviews, vol. 26, pp. 739-751.
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Ismail, MS, Moghavvemi, M & Mahlia, TMI 2013, 'Characterization of PV panel and global optimization of its model parameters using genetic algorithm', Energy Conversion and Management, vol. 73, pp. 10-25.
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Ismail, MS, Moghavvemi, M & Mahlia, TMI 2013, 'Design of an optimized photovoltaic and microturbine hybrid power system for a remote small community: Case study of Palestine', Energy Conversion and Management, vol. 75, pp. 271-281.
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Ismail, MS, Moghavvemi, M & Mahlia, TMI 2013, 'Techno-economic analysis of an optimized photovoltaic and diesel generator hybrid power system for remote houses in a tropical climate', Energy Conversion and Management, vol. 69, pp. 163-173.
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Jeong, S & Vigneswaran, S 2013, 'Assessment of biological activity in contact flocculation filtration used as a pretreatment in seawater desalination', Chemical Engineering Journal, vol. 228, no. 1, pp. 976-983.
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Contact flocculation filtration (CFF) is a promising pretreatment method to improve feed water quality prior to seawater reverse osmosis (SWRO). CFF is the combination of deep bed filtration and in-line flocculation. To date, CFF has been used mainly as a barrier for particle removal in the filter bed itself with hydrophobic organic compounds removal by flocculation. In this study, the potential of CFF was investigated as a biofilter in addition to its major function of flocculation and particle/floc separation. Two different media (sand; S-CFF and anthracite; A-CFF) were tested on CFF. Bacterial activity in the filter bed was assessed in terms of cell number and adenosine tri-phosphate (ATP) measurement. The microbial community test in the filtration bed was carried out over 50 d in case of sand filter (S-CFF) and 90 d for anthracite filter (A-CFF) filtration periods. With the growth of an active microbial population on the filter bed medium, significant removal of organic compounds, especially low molecular weight (LMW) organics, from the seawater was achieved. The results indicated that CFF functions both as flocculation and separation unit and also as biofilter with moderate efficiency in reducing biofouling potential. The results also showed that A-CFF needed longer time to achieve bio-stabilization but it showed more effective biofiltration potential than S-CFF.
Jeong, S, Bae, H, Naidu, G, Jeong, D, Lee, S & Vigneswaran, S 2013, 'Bacterial community structure in a biofilter used as a pretreatment for seawater desalination', Ecological Engineering, vol. 60, no. 1, pp. 370-381.
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In this study, two biofilters with different media, anthracite and granular activated carbon (GAC), were used to pre-treat seawater for desalination. Both biofilters had the same operating conditions that lasted for 75 days. The bacterial community struc
Jeong, S, Kim, S-J, Kim, CM, Vigneswaran, S, Nguyen, TV, Shon, H-K, Kandasamy, J & Kim, IS 2013, 'A detailed organic matter characterization of pretreated seawater using low pressure microfiltration hybrid systems', JOURNAL OF MEMBRANE SCIENCE, vol. 428, pp. 290-300.
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In this study, two different submerged membrane hybrid systems (SMHSs) namely (i) submerged membrane coagulation hybrid system (SMCHS) and (ii) submerged membrane coagulation-adsorption hybrid system (SMCAHS) were investigated as pretreatment options for seawater reverse osmosis. Organic matters in seawater before and after pretreatment were characterized in terms of XAD fractionation, molecular weight distribution (MWD) and fluorescence. A detailed study on the seawater organic matter (SWOM) structure was made through 1H-nuclear magnetic resonance (1H NMR), pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) and liquid chromatography-mass spectrometry-ion trap-time of fright (LC/MS-IT-TOF). The seawater investigated in this study is mainly composed of hydrophilic matter (57±3.2%). SMHSs removed a significant amount of organic matter. The EEM fluorescence showed a removal of humic-like materials by SMHSs. In addition, humic-like materials relative to protein-like compounds were reduced significantly but the aromaticity of humic-like materials increased. After pretreatment by SMHSs, humics and biopolymers of over 900Da. were found to be reduced and their structure associated with element composition was also changed. The transformation of the SWOM structure after SMHSs pretreatment may have been due to hydrolyzation or oxidization of the organic compounds such as humics and biopolymers resulting in poly-conjugation to aromatic compounds. SMHSs were effective in improving the RO performance leading to higher RO permeate flux and lower permeate flux decline. The pretreatment reduced the amount of foulants on the RO membrane. © 2012 Elsevier B.V.
Jeong, S, Kim, S-J, Kim, LH, Shin, MS, Vigneswaran, S, Nguyen, TV & Kim, IS 2013, 'Foulant analysis of a reverse osmosis membrane used pretreated seawater', JOURNAL OF MEMBRANE SCIENCE, vol. 428, pp. 434-444.
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This study focused on the characterization of organic and biological foulants on reverse osmosis (RO) membrane and fouled RO membrane characterization with seawater pretreated by submerged membrane hybrid systems (SMHSs). New low pressure membrane based pretreatments namely submerged membrane coagulation hybrid system (SMCHS) and submerged membrane coagulation-adsorption hybrid system (SMCAHS) were investigated. Organic foulants on RO membrane were characterized in terms of molecular weight distribution (MWD), fluorescence and extracellular polymeric substance (EPS) analyses. The organic foulants were mainly composed of high molecular weight matters representing biopolymers in the foulants. The fluorescence excitation-emission matrix (F-EEM) analysis showed that protein-like materials were dominant with samples pretreated by SMHSs. Humic-like materials which have lower aromaticity were also present in the foulant. Biological foulants were investigated in terms of total direct cell (TDC) count, cell viability and biomass activity (adenosine tri-phosphate; ATP). Biological fouling was found to be reduced by organic removal with SMHSs. The fouled membranes were characterized using environmental scanning electron microscopy coupled with energy dispersive spectroscopy, attenuated total reflection-Fourier transform infrared spectrometry, zeta-potential measurement, atomic force microscopy, and contact angle measurement. © 2012 Elsevier B.V.
Jeong, S, Naidu, G & Vigneswaran, S 2013, 'Submerged membrane adsorption bioreactor as a pretreatment in seawater desalination for biofouling control', Bioresource Technology, vol. 141, no. 1, pp. 57-64.
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Submerged membrane adsorption bioreactor (SMABR) was investigated as a pretreatment to reverse osmosis (RO). SMABR removed organic matter by adsorption and biological degradation. At a powder activated carbon (PAC) residence time of 66 d (1.5% of PAC replacement daily), higher organic removal was achieved with removal of a majority of biopolymers (9497%) and humics (7176%). A continuous MBR operation with the optimal PAC residence time of 66 d was conducted and compared with MBR with no PAC replenishment in terms of the removal of organic and microbes. High removal of organics of up to 72% was maintained with only a marginal increment of trans-membrane pressure and stable bioactivity (total cell number and adenosine tri-phosphate) during the 50 d of operation. The SMABR was found to be a sustainable biological pretreatment to RO with only a small amount of PAC requirement (2.14 g of PAC/m3 of seawater treated).
Jeong, S, Naidu, G, Vigneswaran, S, Ma, CH & Rice, SA 2013, 'A rapid bioluminescence-based test of assimilable organic carbon for seawater', Desalination, vol. 317, pp. 160-165.
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The accumulation of biological materials and bacteria on water purification membranes, termed biofouling, is associated with decreased membrane performance and increased cost of operation. One strategy to minimize biofouling is pretreatment of the influent water. In this regard, tools and indicators that can assess the influent water are required, enabling an optimum selection of pretreatment methods. One parameter directly linked to biofouling potential is the concentration of assimilable organic carbon (AOC) in the feed-water. High AOC levels are associated with increased growth potential of the microbial fouling community. This work focused on the development of a new method for rapid and accurate quantification of AOC concentration in seawater. The method is based on the quantification of the bioluminescence response of the marine bacterium Vibrio fischeri MJ-1. Compared to previous methods, this new V. fischeri method was rapid (within 1. h), sensitive (detection limit. = 0.1. μg-C glucose equivalents/L) and highly suitable for seawater samples. V. fischeri method was evaluated using real seawater samples. The results showed positive reproductive AOC values. The new V. fischeri AOC method developed has a highly promising potential to be practically adopted as a rapid indicator of AOC concentration and hence biofouling potential of influent marine water. © 2013 Elsevier B.V.
Jeong, S, Okour, Y, Nguyen, TV, Shon, HK & Vigneswaran, S 2013, 'Ti-salt flocculation for dissolved organic matter removal in seawater', DESALINATION AND WATER TREATMENT, vol. 51, no. 16-18, pp. 3591-3596.
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In this study, the removal of different fractions of organic matter in seawater was investigated using titanium tetrachloride (TiCl4) flocculation and compared with ferric chloride (FeCl3) flocculation. The organic matter fractions were characterised using liquid chromatography-organic carbon detector (LC-OCD). Results showed the hydrophobic compounds removal was dominant by both flocculants. However, the removal of hydrophilic organic compounds, such as humics and low-molecular weight neutral compounds of seawater, was superior by TiCl4 flocculation compared to FeCl3 flocculation and this removal increased considerably with the increase of TiCl4 doses. The flocculated sludge after TiCl4 flocculation was incinerated to produce titanium dioxide (TiO2) nanoparticle. TiO2 from seawater sludge characterised by X-ray diffraction (XRD) and scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDS) showed predominant anatase phase with Si as a main dopant. © 2013 Copyright Balaban Desalination Publications.
Jia, W, Liang, S, Ngo, HH, Guo, W, Zhang, J, Wang, R & Zou, Y 2013, 'Effect of phosphorus load on nutrients removal and N2O emission during low-oxygen simultaneous nitrification and denitrification process', BIORESOURCE TECHNOLOGY, vol. 141, no. 1, pp. 123-130.
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Three laboratory scale anaerobicaerobic (low-oxygen) SBRs (R1, R2 and R3) were conducted at different influent phosphorus concentration to evaluate the impacts of phosphorus load on nutrients removal and nitrous oxide (N2O) emission during low-oxygen simultaneous nitrification and denitrification (SND) process. The results showed that TP and TN removals were enhanced simultaneously with the increase in phosphorus load. It was mainly caused by the enrichment of polyphosphate accumulating organisms (PAOs) under high phosphorus load and low COD/P ratio (<50), which could use nitrate/nitrite as electron acceptors to take up the phosphorus. N2O emission was reduced with increasing phosphorus load. N2O-N emission amount per cycle of R3 was 24.1% lower than that of R1. It was due to the decrease of N2O yield by heterotrophic denitrification. When the phosphorus load increased from R1 to R3, heterotrophic denitrification (D) ranged from 42.6% to 36.6% of the N2O yield.
Jia, W, Liang, S, Zhang, J, Ngo, HH, Guo, W, Yan, Y & Zou, Y 2013, 'Nitrous oxide emission in low-oxygen simultaneous nitrification and denitrification process: Sources and mechanisms', BIORESOURCE TECHNOLOGY, vol. 136, no. 1, pp. 444-451.
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This study attempts to elucidate the emission sources and mechanisms of nitrous oxide (N2O) during simultaneous nitrification and denitrification (SND) process under oxygen-limiting condition. The results indicated that N2O emitted during low-oxygen SND process was 0.8 ± 0.1 mg N/gMLSS, accounting for 7.7% of the nitrogen input. This was much higher than the reported results from conventional nitrification and denitrification processes. Batch experiments revealed that nitrifier denitrification was attributed as the dominant source of N2O production. This could be well explained by the change of ammonia-oxidizing bacteria (AOB) community caused by the low-oxygen condition. It was observed that during the lowoxygen SND process, AOB species capable of denitrification, i.e., Nitrosomonas europaea and Nitrosomonas-like, were enriched whilst the composition of denitrifiers was only slightly affected. N2O emission by heterotrophic denitrification was considered to be limited by the presence of oxygen and unavailability of carbon source.
Johir, MA, Shanmuganathan, S, Vigneswaran, S & Kandasamy, J 2013, 'Performance of submerged membrane bioreactor (SMBR) with and without the addition of the different particle sizes of GAC as suspended medium', BIORESOURCE TECHNOLOGY, vol. 141, pp. 13-18.
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In this study the effect of different particle sizes of granular activated carbon (GAC) on the performance of a submerged membrane bioreactor (SMBR) was investigated. The sizes of GAC used were 150-300, 300-600 and 600-1200μm. The SMBR was operated at a filtration flux of 20L/m2h. The removal of dissolved organic carbon (DOC) and chemical oxygen demand (COD) with the addition of GAC was 95%. The concentration of biopolymers, humic, building block and low molecular weight neutral and acids in the SMBR effluent was reduced by 20%, 66-76%, 20-50%, 30-56%, respectively. It helped to reduce the sludge volume index (SVI) and transmembrane pressure (TMP) development by 30-40% and 58%, respectively. However, the removal of NH4+ and PO43- was relatively low of 35-45% and 34-43%, respectively. The SMBR effluent was rich in PO43- and was removed/recovered using hydrated ferric oxide (HFO). The removal of PO43- was almost 90%. © 2013 Elsevier Ltd.
Johir, MAH, Vigneswaran, S, Kandasamy, J & Sleigh, R 2013, 'Coupling of physico-chemical treatment and steel membrane filtration to enhanced organic removal in wastewater treatment', DESALINATION AND WATER TREATMENT, vol. 51, no. 13-15, pp. 2695-2701.
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In this study, the application of steel membrane filtration was tested with the pre-treated wastewater. The pre-treatment methods tested before membrane filtration application were flocculation using FeCl3, Powdered Activated Carbon (PAC) adsorption, purolite ion-exchange column and purolite ion-exchange column followed by flocculation (FeCl3). The effect of two different modes of membrane application (cross-flow and dead-end modes) was examined. The ability of these filters in removing organic matters and solids were examined. It was found that the decline of flux was slightly lower for dead-end mode of operation to that of cross-flow mode of operation. Pre-treatment increased the performance of membrane filtration. The flux decline of raw water (without pre-treatment) was 31-10%, whereas after pre-treatment, it was about 2.5-21%. Pre-treatment followed by microfiltration (MF) showed 68-91% removal efficiency of dissolved organic carbon
Johir, MAH, Vigneswaran, S, Kandasamy, J, BenAim, R & Grasmick, A 2013, 'Effect of salt concentration on membrane bioreactor (MBR) performances: Detailed organic characterization', Desalination, vol. 322, no. 1, pp. 13-20.
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The gradual increase of salt concentration (0 to 35g-NaCl/L) on the performance of membrane bioreactor (MBR) was studied. The uptake rate of dissolved organic carbon and ammonia decreased from around 17.0mg-DOC/g-MLVSS.d to 1.8mg-DOC/g-MLVSS.d and from 8.2mg-NH4-N/g-MLVSS.d to 0mg-NH4-N/g-MLVSS.d respectively when salt concentration reached to 35g-NaCl/L. Similarly the specific oxygen uptake rate (SOUR) reduced from 8 to 9 to around 0.3mg-O2/g-MLVSS.h. The removal of bio-polymers, humic acids, building blocks and low molecular weight neutral decreased with increase in salt concentration. The concentration of dissolved organic nitrogen (DON) in bio-polymer increased from 0.05 to 3.31mg/L when the salt concentration reached to 35g-NaCl/L. This study provides good information for understanding the effect of continuous increase of salt concentration in treating saline wastewater in a MBR process. © 2013.
Kang, S-J, Tijing, LD, Hwang, B-S, Jiang, Z, Kim, HY & Kim, CS 2013, 'Fabrication and photocatalytic activity of electrospun nylon-6 nanofibers containing tourmaline and titanium dioxide nanoparticles', Ceramics International, vol. 39, no. 6, pp. 7143-7148.
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Kim, HJ, Pant, HR, Park, CH, Tijing, LD, Choi, NJ & Kim, CS 2013, 'Hydrothermal growth of mop-brush-shaped ZnO rods on the surface of electrospun nylon-6 nanofibers', Ceramics International, vol. 39, no. 3, pp. 3095-3102.
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Kim, HJ, Pant, HR, Park, CH, Tijing, LD, Hwang, BS, Choi, NJ & Kim, CS 2013, 'Electrical properties of ZnO/nylon-6 spider-wave-like nanonets prepared via electrospinning', Digest Journal of Nanomaterials and Biostructures, vol. 8, pp. 385-393.
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In this work, ZnO nanoparticles (NPs) incorporated electrospun nylon-6 spider-wave-like nanonets with improved electrical properties were successfully fabricated by simple blending of ZnO NPs with nylon-6 solution. Proper dispersion of ZnO NPs with nylon-6 solution not only produce well distributed ZnO NPs on/into the fibres but also accelerate the formation of large number of thin fibres in the form of spider-wave-like nanonets. The incorporation of ZnO NPs through spider-wave-like nylon-6 nanonets was verified by FESEM, EDX, TEM, TGA, FT-IR analysis. The electrical properties of pristine nylon-6 and ZnO/nylon-6 composite fibres was investigated by current-voltage (I-V) characteristic measurement. It was found that ZnO incorporated nylon-6 composite mats had better electrical conductivity than pristine nylon-6 mat. This result was due to the influence of ultrathin nanofibers and well incorporated ZnO NPs through electrospun nylon-6 fibers. The significant enhanced electrical properties of composite mat may open a new direction for future polymer electronics.
Kim, JE, Phuntsho, S & Shon, HK 2013, 'Pilot-scale nanofiltration system as post-treatment for fertilizer-drawn forward osmosis desalination for direct fertigation', DESALINATION AND WATER TREATMENT, vol. 51, no. 31-33, pp. 6265-6273.
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The integration of the fertilizer-drawn forward osmosis with nanofiltration (NF) has been investigated to evaluate the performance of NF process as a post-treatment. The primary objective of this study is to optimize the operating conditions such as feed flow rate and feed concentration, while producing fresh water including low nutrient (N) concentration can be directly used for irrigation. Investigation of operating parameters at the pilot-scale level focused on specific water flux and ammonium sulphate rejection. Results from this study showed that NF process applied as the post-treatment can effectively reject the N concentration more than 90%. Although other factors such as the applied pressure and the cross-flow rates played a certain role in the performance of the pilot-scale NF process, the influence of the feed concentration was more significant on the specific water flux and N rejection. © 2013 Copyright Balaban Desalination Publications.
Kim, TH, Hwang, BS, Kang, HY, Kim, JH, Tijing, LD, Kim, CS & Lim, JK 2013, 'Enhanced wetting and adhesion of polycarbonate by ultraviolet light surface treatment', Digest Journal of Nanomaterials and Biostructures, vol. 8, no. 4, pp. 1415-1421.
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In this study, polycarbonate (PC) surfaces were treated with ultraviolet (UV) light irradiation at different treatment times (0 to 48 h) and at two UV wavelengths, i.e., at 365 nm (UVA) and at 254 nm (UVC). Morphological and surface properties were characterized by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and contact angle (CA) measurements. To check the shear strength of the treated polycarbonates, single-lap shear test was carried out. Both UVA and UVC treatment produced rougher PC surface compared to untreated PC, however, UVA did not affect much the wettability of PC. But for UVC treatment, the CA of PC decreased with increasing treatment time to a maximum reduction of 23% after 48 h. The shear strength of UVC-treated PC increased by 63% than that of untreated PC, which is attributed to the formation of functional groups at the surface making it hydrophilic and the rougher surface topography that gives more surface area for adhesion.
Kong, Q, Zhang, J, Ngo, HH, Ni, S, Fu, R, Guo, W, Guo, N & Tian, L 2013, 'Nitrous oxide emission in an aerobic granulation sequencing batch airlift reactor at ambient temperatures', INTERNATIONAL BIODETERIORATION & BIODEGRADATION, vol. 85, no. 1, pp. 533-538.
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This study aims to investigate the nitrous oxide (N2O) emission in an aerobic granulation sequencing batch airlift reactor (SBAR) and the associated microbial community of aerobic granular sludge at ambient temperature (18+-3)0C. After 48 days of operation, 1-2 mm granules were obtained and excellent chemical oxygen demand (COD) and ammonium NH4-N removal efficiencies were stably achieved. N2O concentration in the off gas was maximal at the beginning of the aerobic period and stabilized at a lower concentration after an initial peak. (0.60+-0.17, n=3) % of the total nitrogen load to the SBAR was emitted as N2O. A dramatic change in the microbial community structure was noted between the initial seed sludge and the final mature aerobic granular sludge. Nitrosospira was identified to be the dominant ammonium oxidizing bacteria (AOB) which was attributed as the dominant source of N2O production in aerobic granular sludge by analysis of 16S rDNA sequences.
Kraemer, WE, Schrameyer, V, Hill, R, Ralph, PJ & Bischof, K 2013, 'PSII activity and pigment dynamics of Symbiodinium in two Indo-Pacific corals exposed to short-term high-light stress', MARINE BIOLOGY, vol. 160, no. 3, pp. 563-577.
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This study examined the capacity for photoprotection and repair of photo-inactivated photosystem II in the same Symbiodinium clade associated with two coexisting coral species during high-light stress in order to test for the modulation of the symbionts photobiological response by the coral host. After 4 days exposure to in situ irradiance, symbionts of the bleaching-sensitive Pocillopora damicornis showed rapid synthesis of photoprotective pigments (by 44 %) and strongly enhanced rates of xanthophyll cycling (by 446 %) while being insufficient to prevent photoinhibition (sustained loss in F v/F m at night) and loss of symbionts after 4 days. By contrast, Pavona decussata showed no significant changes in F v/F m, symbiont density or xanthophyll cycling. Given the association with the same Symbiodinium clade in both coral species, our findings suggest that symbionts in the two species examined may experience different in hospite light conditions as a result of different biometric properties of the coral host.
Kus, B, Kandasamy, J, Vigneswaran, S, Shon, HK & Moody, G 2013, 'Gravity driven membrane filtration system to improve the water quality in rainwater tanks', WATER SCIENCE AND TECHNOLOGY-WATER SUPPLY, vol. 13, no. 2, pp. 479-485.
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The characterisation of rainwater in metropolitan Sydney and in rural New South Wales was undertaken. The results showed that factors such as the lack of vehicular traffic, air pollution and urban contamination meant that rural rainwater water quality was better. The rain water collected in both metropolitan and rural areas generally complied with the 2004 Australian Drinking Water Guidelines except for parameters such as the pH in both the metropolitan and rural rainwater tanks and the turbidity, and lead levels from the metropolitan tanks. This paper also reports the results of a laboratory and a pilot scale study with a deep bed filter (granular activated carbon, GAC) and microfiltration (MF) hollow fibre membrane filter system used to treat raw rainwater collected from a metropolitan rainwater tank. The results of the laboratory experiment and pilot scale systems focus on the non-compliant parameters of the sampling program, i.e. turbidity, lead and dissolved organic carbon (DOC). It was found that rainwater treated by the GAC filter removed the majority of the turbidity and organic substances. The treatment system reduced the concentration of turbidity, lead and DOC to below the Australian Drinking Water Guidelines limits. The pilot plant experiment demonstrated that a GAC filter system and gravity driven membrane could result in low cost and low maintenance operation.
Kus, B, Kandasamy, J, Vigneswaran, S, Shon, HK & Moody, G 2013, 'Household rainwater harvesting system - pilot scale gravity driven membrane-based filtration system', WATER SCIENCE AND TECHNOLOGY-WATER SUPPLY, vol. 13, no. 3, pp. 790-797.
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This paper presents the results of a pilot scale study consisting of pre-treatment with a granular activated carbon (GAC) filter followed by membrane filtration. Detailed characterisation of rainwater tanks has highlighted that turbidity, dissolved organic carbon (DOC) and heavy metals, in particular lead, were not compliant with the 2004 Australian Drinking Water Guidelines (ADWG). Further, organic matter present in the water causes membrane fouling and leads to carcinogenic compounds upon chlorination. A GAC filter was used as a first step to remove dissolved organic matter (measured in terms of DOC) in particular and also to reduce the concentration, of turbidity and lead. Membrane filtration can remove any remaining solids reducing the concentrations of turbidity and microorganisms. In this study a pilot scale rainwater treatment system consisting of a gravity fed GAC filter and membrane filter (Ultra Flo) was operated for a period of 120 days. The performance of this system was assessed in terms of membrane flux and improvement in water quality measured against the 2004 Australian Drinking Water Guidelines. Determination of the flux especially in the later stages of membrane operation was important to be able to size the filters in a manner that meets the expected demand. The treatment system of GAC filter and membrane filter was effective in reducing the turbidity, DOC and heavy metals. The system reduced the turbidity to levels of 0.30.4 NTU, below the ADWG limit of 1 NTU.
Li, C, Liang, S, Zhang, J, Ngo, HH, Guo, W, Zheng, N & Zou, Y 2013, 'N2O reduction during municipal wastewater treatment using a two-sludge SBR system acclimatized with propionate', CHEMICAL ENGINEERING JOURNAL, vol. 222, pp. 353-360.
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A two-sludge denitrifying phosphorus removal process (A2N-SBR), acclimatized with propionate, was proposed as an efficient method for nitrous oxide (N2O) reduction during municipal wastewater treatment. Compared with the conventional nitrification-denitrification process (AO-SBR) operated in parallel, the A2N-SBR not only significantly improved total nitrogen and soluble phosphorus removal efficiencies by around 32.3% and 23.5%, respectively, but also greatly reduced N2O generation by around 31.5%. Moreover, like the anoxic stage of AO-SBR, nearly zero N2O (merely 0.054% of the removed nitrogen) was generated during the anoxic stage of A2N-SBR. The substantial N2O reduction achieved in the proposed A2N-SBR can be reasonably explained by: (i) the use of independent nitrification reactor resulting in higher activity of nitrifying bacteria and no occurrence of heterotrophic denitrification in aerobic stage, and (ii) the use of propionate as carbon source decreasing nitrite accumulation in anoxic stage. © 2013 Elsevier B.V.
Li, C, Wang, T, Zheng, N, Zhang, J, Ngo, HH, Guo, W & Liang, S 2013, 'Influence of organic shock loads on the production of N2O in denitrifying phosphorus removal process', BIORESOURCE TECHNOLOGY, vol. 141, no. 1, pp. 160-166.
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In this work, the influences of short-term organic shock loads on N2O production during denitrifying phosphorus removal were investigated by changing the influent COD concentrations (100, 200, 350, and 500mg/L). After switching the COD concentrations from 200 to 350 or 500mg/L, N2O-N production amount increased from 1.62% to 7.12% or 3.29% of the TN removal, respectively, while the corresponding effluent phosphorus concentrations increased from 1.84 to 16.55 and 56.08mg/L, respectively, which were higher than the influent phosphorus concentration (4.93mg/L). Furthermore, when the COD concentration was decreased to 100mg/L, N2O-N production amount was only 1.20%. All results suggested that higher organic shock loads increased N2O production. The main reason was that higher organic shock loads increased anaerobic poly-β-hydroxyalkanoates (PHA) synthesis, which resulted in higher nitrite accumulation. The influences of higher organic shock loads on N2O production could be minimized by adopting continuous nitrate addition strategy. © 2013 Elsevier Ltd.
Li, C, Zhang, J, Liang, S, Ngo, HH, Guo, W, Zhang, Y & Zou, Y 2013, 'Nitrous oxide generation in denitrifying phosphorus removal process: main causes and control measures', ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, vol. 20, no. 8, pp. 5353-5360.
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Despite the many benefits of denitrifying phosphorus removal process, the significant generation of nitrous oxide (N2O), a potent greenhouse gas, remains a problem for this innovative and promising process. To better understand and more effectively control N2O generation in denitrifying phosphorus removal process, batch experiments were carried out to investigate the main causes of N2O generation, based on which the control measures were subsequently proposed. The results showed that N2O generation accounted for 0.41 % of the total nitrogen removal in denitrifying phosphorus removal process, whereas, in contrast, almost no N2O was generated in conventional denitrification process. It was further demonstrated that the weak competition of N2O reductase for electrons and the high nitrite accumulation were the two main causes for N2O generation, evidenced by N2O production and reduction rates under different conditions. Accordingly, the reduction of N2O generation was successfully achieved via two control measures: (1) the use of continuous nitrate addition reducing N2O generation by around 91.4 % and (2) the use of propionate as the carbon source reducing N2O generation by around 69.8 %. © 2013 Springer-Verlag Berlin Heidelberg.
Li, J, Li, J, Wang, H, Cheng, B, He, B, Yan, F, Yang, Y, Guo, W & Ngo, HH 2013, 'ChemInform Abstract: Electrocatalytic Oxidation of n‐Propanol to Produce Propionic Acid Using an Electrocatalytic Membrane Reactor.', ChemInform, vol. 44, no. 37, pp. no-no.
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AbstractAn electrocatalytic membrane reactor assembled using a nano‐MnO2 loading microporous Ti membrane as an anode and a tubular stainless steel as a cathode is used to oxidize PrOH to produce propionic acid.
Li, J, Li, J, Wang, H, Cheng, B, He, B, Yan, F, Yang, Y, Guo, W & Ngo, HH 2013, 'Electrocatalytic oxidation of n-propanol to produce propionic acid using an electrocatalytic membrane reactor', CHEMICAL COMMUNICATIONS, vol. 49, no. 40, pp. 4501-4503.
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An electrocatalytic membrane reactor assembled using a nano-MnO2 loading microporous Ti membrane as an anode and a tubular stainless steel as a cathode was used to oxidize n-propanol to produce propionic acid. The high efficiency and selectivity obtained is related to the synergistic effect between the reaction and separation in the reactor.
Li, Q, Wang, XC, Zhang, HH, Shi, HL, Hu, T & Ngo, HH 2013, 'Characteristics of nitrogen transformation and microbial community in an aerobic composting reactor under two typical temperatures', BIORESOURCE TECHNOLOGY, vol. 137, pp. 270-277.
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Batch experiments were conducted for feces composting using an aerobic composting reactor with sawdust as bulky matrix. In the 14-day composting processes at 35 ± 2 and 55 ± 2 C, compost samples were collected daily and chemical analyses and PCR-DGGE were carried out for investigating the influence of composting temperature on organic decomposition, nitrogen transformation, and microbial communities. At 55 ± 2 C, in addition to a slightly higher COD removal, nitrogen loss was greatly restrained. As organic nitrogen took about 85% of the total nitrogen originated from human feces, the suppression of ammonification process under thermophilic environment might be the main reason for less nitrogen loss at 55 ± 2 C. By PCR-DGGE analysis, the microbial community was found to undergo successions differently at 35 ± 2 and 55 ± 2 C. Certain sequences identified from the compost at 55 ± 2 C represented the microbial species which could perform nitrogen-fixation or sustain a lower pH in the compost so that gaseous ammonia emission was suppressed.
Liaquat, AM, Masjuki, HH, Kalam, MA, Fattah, IMR, Hazrat, MA, Varman, M, Mofijur, M & Shahabuddin, M 2013, 'Effect of Coconut Biodiesel Blended Fuels on Engine Performance and Emission Characteristics', Procedia Engineering, vol. 56, pp. 583-590.
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Liaquat, AM, Masjuki, HH, Kalam, MA, Fazal, MA, Khan, AF, Fayaz, H & Varman, M 2013, 'Impact of palm biodiesel blend on injector deposit formation', Applied Energy, vol. 111, pp. 882-893.
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Listowski, A, Ngo, HH & Guo, WS 2013, 'Establishment of an economic evaluation model for urban recycled water', RESOURCES CONSERVATION AND RECYCLING, vol. 72, pp. 67-75.
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This study aimed at establishing an economic evaluation model to encourage continuing improvement in performance analysis and applying for any infrastructure system of urban recycled water. A thorough study towards characterization and economic performance assessment of urban water reuse scheme were carried out. An integrated evaluation technique was developed by synthesizing the quantitative and qualitative performance indicators related to the water recycled technology and urban water cycle system. Specific performance indicators and indexes were aggregated into an economic analytical modelling for effective evaluation of the water reuse scheme and technology using uniform economic performance standards. Detailed economic analyses were successfully applied to enable determination of economic lifetime of the technology and the whole water reuse scheme. This research confirmed that productivity, efficiency and reliability measurements and factors could be successfully deployed for determining the scheme performance during various life cycle stages (e.g. design development, operational and functional verification, or comparison with other reuse projects). The economic assessment model was applied to improve uniformity of analytical process and performance measure. This article demonstrates benefits associated with the application of a standardized methodology for performing economic assessment and by maintaining strong correlation between multi-parameter approach and adopted performance criteria in terms of productivity, efficiency and reliability. However, to ensure effectiveness of this assessment, the process would require systematic and perpetual inventory of the scheme performance data, consideration of variable factors such as capital and recurrent costs.
Loganathan, P, Vigneswaran, S & Kandasamy, J 2013, 'Enhanced removal of nitrate from water using surface modification of adsorbents - A review', JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol. 131, no. 1, pp. 363-374.
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Elevated concentration of nitrate results in eutrophication of natural water bodies affecting the aquatic environment and reduces the quality of drinking water. This in turn causes harm to people's health, especially that of infants and livestock. Adsorbents with the high capacity to selectively adsorb nitrate are required to effectively remove nitrate from water. Surface modifications of adsorbents have been reported to enhance their adsorption of nitrate. The major techniques of surface modification are: protonation, impregnation of metals and metal oxides, grafting of amine groups, organic compounds including surfactant coating of aluminosilicate minerals, and heat treatment. This paper reviews current information on these techniques, compares the enhanced nitrate adsorption capacities achieved by the modifications, and the mechanisms of adsorption, and presents advantages and drawbacks of the techniques. Most studies on this subject have been conducted in batch experiments. These studies need to include continuous mode column trials which have more relevance to real operating systems and pilot-plant trials. Reusability of adsorbents is important for economic reasons and practical treatment applications. However, only limited information is available on the regeneration of surface modified adsorbents, © 2013 Elsevier Ltd.
Loganathan, P, Vigneswaran, S & Kandasamy, J 2013, 'Road-Deposited Sediment Pollutants: A Critical Review of their Characteristics, Source Apportionment, and Management', CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 43, no. 13, pp. 1315-1348.
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Road-deposited sediments (RDS) often contain elevated concentrations of inorganic and organic pollutants such as heavy metals, metalloids, and polycyclic aromatic hydrocarbons. The authors trace new developments and trends on RDS pollutant characteristics with respect to their distribution in time and space, total and labile fractions in the different particle size and density fractions, source apportionment, and chemical speciation, as well as on the management of the pollutants. Recent research provides more reliable information to understand pollutants origin, bioavailability, transport pathways, and methods to minimize their risks. Use of special chemical, physical, mineralogical, and statistical methods has contributed to a better understanding of source apportionment of many of the pollutants but more research is needed on others. The degree of accumulation of pollutants in RDS that are derived from roads and vehicles has been quantified by using enrichment factors. Many of the studies on RDS pollutant management dealt with reducing pollutants by road sweeping and water flushing but these have not been found to be very effective. Pollutants that enter the water bodies through stormwater runoff need to be removed to protect the aquatic environment in the receiving water. The current knowledge on stormwater treatment methods to remove pollutants is also presented. © 2013 Copyright Taylor and Francis Group, LLC.
Loganathan, P, Vigneswaran, S, Kandasamy, J & Naidu, R 2013, 'Defluoridation of drinking water using adsorption processes', JOURNAL OF HAZARDOUS MATERIALS, vol. 248, no. 1, pp. 1-19.
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Excessive intake of fluoride (F), mainly through drinking water, is a serious health hazard affecting humans worldwide. There are several methods used for the defluoridation of drinking water, of which adsorption processes are generally considered attractive because of their effectiveness, convenience, ease of operation, simplicity of design, and for economic and environmental reasons. In this paper, we present a comprehensive and a critical literature review on various adsorbents used for defluoridation, their relative effectiveness, mechanisms and thermodynamics of adsorption, and suggestions are made on choice of adsorbents for various circumstances. Effects of pH, temperature, kinetics and co-existing anions on F adsorption are also reviewed. Because the adsorption is very weak in extremely low or high pHs, depending on the adsorbent, acids or alkalis are used to desorb F and regenerate the adsorbents. However, adsorption capacity generally decreases with repeated use of the regenerated adsorbent. Future research needs to explore highly efficient, low cost adsorbents that can be easily regenerated for reuse over several cycles of operations without significant loss of adsorptive capacity and which have good hydraulic conductivity to prevent filter clogging during the fixed-bed treatment process. © 2013 Elsevier B.V.
Ma, XY, Wang, XC, Ngo, HH, Guo, W, Wu, MN & Wang, N 2013, 'Reverse osmosis pretreatment method for toxicity assessment of domestic wastewater using Vibrio qinghaiensis sp.-Q67', ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, vol. 97, no. 1, pp. 248-254.
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Luminescent bacterial test is a fast and sensitive method for acute toxicity assessment of water and wastewater. In this study, an improved toxicity testing method was developed using the freshwater luminescent bacteria Vibrio qinghaiensis sp.-Q67 that involved pretreatment of water samples with reverse osmosis (RO) to eliminate the interferences caused by nutrients in concentrated samples and to improve the reliability and sensitivity of the analysis. Because water samples contain low concentrations of several target toxic substances, rapid acute toxicity testing method that is commonly employed does not achieve enough sensitivity. The proposed RO pretreatment could effectively enrich organic and inorganic substances in water samples to enable a more effective and sensitive toxicity evaluation. The kinetic characteristics of toxicity of raw sewage and secondary effluent were evaluated based on the relative luminescence unit (RLU) curves and timeconcentration-effect surfaces. It was observed that when the exposure time was prolonged to 8-h or longer, the bacteria reached the logarithmic growth stage. Hence, the stimulating effects of the coexisting ions (such as Na+, K+, NO3-) in the concentrated samples could be well eliminated. A 10-h exposure time in proposed Q67 test was found to quantitatively evaluate the toxicity of the organic and inorganic pollutants in the RO-concentrated samples.
Mahlia, TMI, Tohno, S & Tezuka, T 2013, 'International experience on incentive program in support of fuel economy standards and labelling for motor vehicle: A comprehensive review', Renewable and Sustainable Energy Reviews, vol. 25, pp. 18-33.
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Mainali, B, Pham, TTN, Ngo, HH & Guo, W 2013, 'Maximum allowable values of the heavy metals in recycled water for household laundry', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 452, no. 1, pp. 427-432.
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Household laundry as a new end use of recycled water in dual reticulation systems has a great potential as the significant amount of potable water from urban households can be saved. However, there is still no sufficient evidence and supporting recycled water quality guidelines for this particular use. A key gap in knowledge is the impact of heavy metals in recycled water on clothes and washing machines. Thus, this study aims to determine the maximum allowable values (MAVs) of the heavy metals iron (Fe), lead (Pb), zinc (Zn), copper (Cu), and manganese (Mn) in recycled water for washing clothes in washing machines. Six different concentrations of each targeted metals were prepared in tap water for the washing machine experiments. The tearing/tensile strength tests were used for the assessment of cloth durability. MINITAB 16 as a statistical tool was used and ANOVA one way test was applied for the significance analysis (Turkey's test p. <. 0.05). The results show that the MAVs of the heavy metals Fe, Pb, Zn, Cu and Mn were found to be 1. mg/l, 1. mg/l, 10. mg/l, 5. mg/l and 1. mg/l respectively in terms of cloth durability. © 2013 Elsevier B.V.
Mainali, B, Pham, TTN, Ngo, HH, Guo, W, Miechel, C, O'Halloran, K, Muthukaruppan, M & Listowski, A 2013, 'Vision and perception of community on the use of recycled water for household laundry: A case study in Australia', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 463, no. 1, pp. 657-666.
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This study investigates the community perception of household laundry as a new end use of recycled water in three different locations of Australia through a face to face questionnaire survey (n=478). The study areas were selected based on three categories of (1) non-user, (2) perspective user and (3) current user of recycled water. The survey results indicate that significantly higher number (70%) of the respondents supported the use of recycled water for washing machines (χ2=527.40, df=3; p=0.000). Significant positive correlation between the overall support for the new end use and the willingness of the respondents to use recycled water for washing machine was observed among all users groups (r=0.43, p=0.000). However, they had major concerns regarding the effects of recycled water on the aesthetic appearance of cloth, cloth durability, machine durability, odour of the recycled water and cost along with the health issues. The perspective user group had comparatively more reservations and concerns about the effects of recycled water on washing machines than the non-users and the current users (χ2=52.73, df=6; p=0.000). Overall, community from all three study areas are willing to welcome this new end use as long as all their major concerns are addressed and safety is assured. © 2013 Elsevier B.V.
Masjuki, HH, Kalam, MA, Mofijur, M & Shahabuddin, M 2013, 'Biofuel: Policy, Standardization and Recommendation for Sustainable Future Energy Supply', Energy Procedia, vol. 42, pp. 577-586.
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Masum, BM, Masjuki, HH, Kalam, MA, Rizwanul Fattah, IM, Palash, SM & Abedin, MJ 2013, 'Effect of ethanol–gasoline blend on NOx emission in SI engine', Renewable and Sustainable Energy Reviews, vol. 24, pp. 209-222.
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Mehrali, M, Latibari, ST, Mehrali, M, Indra Mahlia, TM & Cornelis Metselaar, HS 2013, 'Preparation and properties of highly conductive palmitic acid/graphene oxide composites as thermal energy storage materials', Energy, vol. 58, pp. 628-634.
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Mehrali, M, Latibari, ST, Mehrali, M, Indra Mahlia, TM, Cornelis Metselaar, HS, Naghavi, MS, Sadeghinezhad, E & Akhiani, AR 2013, 'Preparation and characterization of palmitic acid/graphene nanoplatelets composite with remarkable thermal conductivity as a novel shape-stabilized phase change material', Applied Thermal Engineering, vol. 61, no. 2, pp. 633-640.
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Mofijur, M, Atabani, AE, Masjuki, HH, Kalam, MA & Masum, BM 2013, 'A study on the effects of promising edible and non-edible biodiesel feedstocks on engine performance and emissions production: A comparative evaluation', Renewable and Sustainable Energy Reviews, vol. 23, pp. 391-404.
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Mofijur, M, Masjuki, HH, Kalam, MA & Atabani, AE 2013, 'Evaluation of biodiesel blending, engine performance and emissions characteristics of Jatropha curcas methyl ester: Malaysian perspective', Energy, vol. 55, pp. 879-887.
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Mofijur, M, Masjuki, HH, Kalam, MA, Atabani, AE, Shahabuddin, M, Palash, SM & Hazrat, MA 2013, 'Effect of biodiesel from various feedstocks on combustion characteristics, engine durability and materials compatibility: A review', Renewable and Sustainable Energy Reviews, vol. 28, pp. 441-455.
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Naidu, G, Jeong, S, Vigneswaran, S & Rice, SA 2013, 'Microbial activity in biofilter used as a pretreatment for seawater desalination', Desalination, vol. 309, pp. 254-260.
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Biofilters as a pretreatment process in seawater desalination can reduce biofoulants through adsorption and biodegradation. In this study, the performance of granular activated carbon (GAC) biofilter with three different filtration velocities was studied in terms of dissolved organic carbon (DOC) removal. This apart, the microbial activities in the biofilters were measured in terms of concentration of active biomass (adenosine tri-phosphate; ATP) and total cell count. Biofouling potential in biofilter effluents were assessed in terms of transparent exopolymer particles (TEP) and assimilable organic carbon (AOC) concentration. AOC was carried out using a new rapid bioluminescence method. Upon reaching mature stage, the GAC biofilters achieved high DOC removal efficiency of more than 60%, especially the low molecular weight organics. This organic removal was mostly attributed to active biomass on the GAC media. In addition, GAC biofilters led to significant reduction of the AOC and TEP concentration amounting to only 0.6. ±0.2. μg-C glucose/L and 5.3 ± 1.1. μg-C/L, respectively in effluents. Thus, GAC biofilter is an effective pretreatment in reducing biofouling potential. © 2012 Elsevier B.V.
Nguyen, LN, Hai, FI, Kang, J, Nghiem, LD, Price, WE, Guo, W, Ngo, HH & Tung, K-L 2013, 'Comparison between sequential and simultaneous application of activated carbon with membrane bioreactor for trace organic contaminant removal', BIORESOURCE TECHNOLOGY, vol. 130, pp. 412-417.
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The removal efficiency of 22 selected trace organic contaminants by sequential application of granular activated carbon (GAC) and simultaneous application of powdered activated carbon (PAC) with membrane bioreactor (MBR) was compared in this study. Both sequential application of GAC following MBR treatment (MBRâGAC) and simultaneous application of PAC within MBR (PACâMBR) achieved improved removal (over 95%) of seven hydrophilic and biologically persistent compounds, which were less efficiently removed by MBR-only treatment (negligible to 70%). However, gradual breakthrough of these compounds occurred over an extended operation period. Charged compounds, particularly, fenoprop and diclofenac, demonstrated the fastest breakthrough (complete and 50â70%, in MBRâGAC and PACâMBR, respectively). Based on a simple comparison from the long-term performance stability and activated carbon usage points of view, PACâMBR appears to be a better option than MBRâGAC treatment.
Nguyen, LN, Hai, FI, Kang, J, Price, WE & Nghiem, LD 2013, 'Removal of emerging trace organic contaminants by MBR-based hybrid treatment processes', International Biodeterioration & Biodegradation, vol. 85, pp. 474-482.
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Nguyen, LN, Hai, FI, Yang, S, Kang, J, Leusch, FDL, Roddick, F, Price, WE & Nghiem, LD 2013, 'Removal of trace organic contaminants by an MBR comprising a mixed culture of bacteria and white-rot fungi', Bioresource Technology, vol. 148, pp. 234-241.
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Nguyen, TAH, Ngo, HH, Guo, WS, Zhang, J, Liang, S & Tung, KL 2013, 'Feasibility of iron loaded 'okara' for biosorption of phosphorous in aqueous solutions', BIORESOURCE TECHNOLOGY, vol. 150, no. 1, pp. 42-49.
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This study investigated the feasibility of using soybean milk by-products (okara) as a sustainable biosorbent for phosphate removal in water and wastewater. The results show that raw okara could hardly decontaminate phosphate from aqueous solutions. Hence, in this work, okara was modified by being cationized using FeCl3 0.25M (namely iron loaded okara, ILO) to enhance the phosphorus adsorption capacity. The phosphate sorption onto ILO was well achieved under the conditions of pH 3, initial phosphorous concentration of 25mg/L, biosorbent dose of 20mg/L and contact time of 7h. Based on Langmuir model, the maximum adsorption capacity of phosphate by ILO was 4.785mg/g. The effects of interfering anions were in the order of CO32->SO42->NO3 It was also observed that Fe(III) was detached during operation. This problem can hinder the sustainable usability of ILO. Thus, further research would be necessary for improving the modification method. © 2013 Elsevier Ltd.
Nguyen, TAH, Ngo, HH, Guo, WS, Zhang, J, Liang, S, Yue, QY, Li, Q & Nguyen, TV 2013, 'Applicability of agricultural waste and by-products for adsorptive removal of heavy metals from wastewater', BIORESOURCE TECHNOLOGY, vol. 148, no. 1, pp. 574-585.
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This critical review discusses the potential use of agricultural waste based biosorbents (AWBs) for sequestering heavy metals in terms of their adsorption capacities, binding mechanisms, operating factors and pretreatment methods. The literature survey indicates that AWBs have shown equal or even greater adsorption capacities compared to conventional adsorbents. Thanks to modern molecular biotechnologies, the roles of functional groups in biosorption process are better understood. Of process factors, pH appears to be the most influential. In most cases, chemical pretreatments bring about an obvious improvement in metal uptake capacity. However, there are still several gaps, which require further investigation, such as (i) searching for novel, multi-function AWBs, (ii) developing cost-effective modification methods and (iii) assessing AWBs under multi-metal and real wastewater systems. Once these challenges are settled, the replacement of traditional adsorbents by AWBs in decontaminating heavy metals from wastewater can be expected in the future. © 2013 Elsevier Ltd.
Nguyen, TT, Ngo, HH & Guo, W 2013, 'Pilot scale study on a new membrane bioreactor hybrid system in municipal wastewater treatment', BIORESOURCE TECHNOLOGY, vol. 141, pp. 8-12.
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A pilot scale membrane bioreactor hybrid system (MBR-HS) was evaluated for municipal wastewater treatment. This novel system comprised of a granular activated carbon-sponge fluidized bed bioreactor (GACS-FBBR) followed by a submerge membrane bioreactor (MBR) with the capacity of 2L/min. The results indicated that the MBR-HS could effectively remove 90% DOC and 95% NH4-N. PO4-P removal efficiency was remained stable at about 70% throughout the experiment. Specific oxygen uptake rate (SOUR) of activated sludge increased from 0.72 to 2.21mg O2/gVSSh for the first 10days and then followed by a steady stage until the end of experiment. Sludge volume index (SVI) was always below 50mL/g, demonstrated an excellent settling properties of sludge. The system also showed an achievement in terms of low trans-membrane pressure (TMP) development rate. The TMP increasing rate was only 0.65kPa/day, suggesting GACS-FBBR can be a promising pre-treatment for MBR. © 2013 Elsevier Ltd.
Nguyen, TT, Ngo, HH & Guo, WS 2013, 'Effect of sponge volume fraction on the performance of a novel fluidized bed bioreactor', WATER SCIENCE AND TECHNOLOGY, vol. 67, no. 11, pp. 2645-2650.
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A novel fluidized bed bioreactor (FBBR) was designed by integration of anaerobic granular activated carbon and aerobic sponge reactors. This FBBR was evaluated at different sponge volume fractions for treating a synthetic wastewater. Polyester urethane sponge with cube size of 1 × 1 × 1 cm and density of 28-30 kg/m3 with 90 cells per 25 mm was used as biomass carrier. The results indicate that the FBBR could remove more than 93% of dissolved organic carbon (DOC). The highest nutrient removal efficiencies (58.2% PO4 -P and 75.4% NH4-N) were achieved at 40% sponge volume fraction. The system could provide a good condition for biomass growth (e.g. 186.2 mg biomass/g sponge). No significant different performance in specific oxygen uptake rate was observed between 30, 40, and 50% sponge volume fractions. © IWA Publishing 2013 Water.
Ni, B, Yuan, Z, Chandran, K, Vanrolleghem, PA & Murthy, S 2013, 'Evaluating four mathematical models for nitrous oxide production by autotrophic ammonia‐oxidizing bacteria', Biotechnology and Bioengineering, vol. 110, no. 1, pp. 153-163.
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AbstractThere is increasing evidence showing that ammonia‐oxidizing bacteria (AOB) are major contributors to N2O emissions from wastewater treatment plants (WWTPs). Although the fundamental metabolic pathways for N2O production by AOB are now coming to light, the mechanisms responsible for N2O production by AOB in WWTP are not fully understood. Mathematical modeling provides a means for testing hypotheses related to mechanisms and triggers for N2O emissions in WWTP, and can then also become a tool to support the development of mitigation strategies. This study examined the ability of four mathematical model structures to describe two distinct mechanisms of N2O production by AOB. The production mechanisms evaluated are (1) N2O as the final product of nitrifier denitrification with NO as the terminal electron acceptor and (2) N2O as a byproduct of incomplete oxidation of hydroxylamine (NH2OH) to NO. The four models were compared based on their ability to predict N2O dynamics observed in three mixed culture studies. Short‐term batch experimental data were employed to examine model assumptions related to the effects of (1) NH concentration variations, (2) dissolved oxygen (DO) variations, (3) NOJournal of Membrane Science, vol. 428, pp. 163-171.
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Ni, B-J, Ruscalleda, M, Pellicer-Nàcher, C & Smets, BF 2013, 'Reply to Comment on “Modeling Nitrous Oxide Production during Biological Nitrogen Removal via Nitrification and Denitrification: Extensions to the General ASM Models”', Environmental Science & Technology, vol. 47, no. 20, pp. 11910-11911.
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Ni, B-J, Smets, BF, Yuan, Z & Pellicer-Nàcher, C 2013, 'Model-based evaluation of the role of Anammox on nitric oxide and nitrous oxide productions in membrane aerated biofilm reactor', Journal of Membrane Science, vol. 446, pp. 332-340.
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Ni, B-J, Ye, L, Law, Y, Byers, C & Yuan, Z 2013, 'Mathematical Modeling of Nitrous Oxide (N2O) Emissions from Full-Scale Wastewater Treatment Plants', Environmental Science & Technology, vol. 47, no. 14, pp. 7795-7803.
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Ong, HC, Silitonga, AS, Masjuki, HH, Mahlia, TMI, Chong, WT & Boosroh, MH 2013, 'Production and comparative fuel properties of biodiesel from non-edible oils: Jatropha curcas, Sterculia foetida and Ceiba pentandra', Energy Conversion and Management, vol. 73, pp. 245-255.
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Palash, SM, Kalam, MA, Masjuki, HH, Masum, BM, Rizwanul Fattah, IM & Mofijur, M 2013, 'Impacts of biodiesel combustion on NOx emissions and their reduction approaches', Renewable and Sustainable Energy Reviews, vol. 23, pp. 473-490.
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Palash, SM, Masjuki, HH, Kalam, MA, Masum, BM, Sanjid, A & Abedin, MJ 2013, 'State of the art of NOx mitigation technologies and their effect on the performance and emission characteristics of biodiesel-fueled Compression Ignition engines', Energy Conversion and Management, vol. 76, pp. 400-420.
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Pan, Y, Ni, B-J & Yuan, Z 2013, 'Modeling Electron Competition among Nitrogen Oxides Reduction and N2O Accumulation in Denitrification', Environmental Science & Technology, vol. 47, no. 19, pp. 11083-11091.
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Pan, Y, Ni, B-J, Bond, PL, Ye, L & Yuan, Z 2013, 'Electron competition among nitrogen oxides reduction during methanol-utilizing denitrification in wastewater treatment', Water Research, vol. 47, no. 10, pp. 3273-3281.
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Pang, SC, Masjuki, HH, Kalam, MA & Hazrat, MA 2013, 'Correlation of Engine Cooling System Parameters and SegmentedHeat Exchangers’ Analysis', Journal of Applied Sciences, vol. 13, no. 11, pp. 2027-2032.
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Pang, SC, Masjuki, HH, Kalam, MA & Hazrat, MA 2013, 'Liquid absorption and solid adsorption system for household, industrial and automobile applications: A review', Renewable and Sustainable Energy Reviews, vol. 28, pp. 836-847.
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Pant, HR, Pant, B, Park, CH, Kim, HJ, Lee, DS, Tijing, LD, Hwang, BS, Kim, HY & Kim, CS 2013, 'RGO/Nylon-6 composite mat with unique structural features and electrical properties obtained from electrospinning and hydrothermal process', Fibers and Polymers, vol. 14, no. 6, pp. 970-975.
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In this work, the reduced graphene oxide (RGO) sheets were effectively uploaded through nylon-6 fibers using combined process of electrospinning and hydrothermal treatment. Good dispersion of graphene oxide (GO) with nylon-6 solution could allow to upload GO sheets through nylon-6 fibers and facilitate the formation of spider-wave-like nano-nets during electrospinning. GO sheets present on/into nylon-6 spider-wave-like nano-nets were further reduced to RGO using hydrothermal treatment. The impregnated GO sheets into nylon-6 nanofibers and their reduction during hydrothermal treatment were confirmed by FE-SEM, TEM, FT-IR and Raman spectra. The electrical characteristics of pristine nylon-6, GO/nylon-6 and RGO/nylon-6 nanofibers were investigated and it was found that RGO/nylon-6 composite mat had better electrical conductivity than others. The formation of spider-wave-like nano-nets as well as indirect route of incorporation of RGO sheets on electrospun nylon-6 mat may open a new direction for future graphene/polymer electronics.
Pant, HR, Pant, B, Pokharel, P, Kim, HJ, Tijing, LD, Park, CH, Lee, DS, Kim, HY & Kim, CS 2013, 'Photocatalytic TiO2–RGO/nylon-6 spider-wave-like nano-nets via electrospinning and hydrothermal treatment', Journal of Membrane Science, vol. 429, pp. 225-234.
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A new route for the formation of reusable photocatalytic TiO2 (P25)-reduced graphene oxide/nylon-6 (P25-RGO/nylon-6) composite filter membrane using electrospinning and hydrothermal techniques is being reported. Addition of small amount of graphene oxide (GO) into nylon-6 solution prior to electrospinning was able to cause the formation of a large-scale uniform bimodal fibers with distributed thick (≈200 nm) and thin (≈13 nm) fiber diameters in spider-wave-like nano-nets by electrospinning, and facilitated the deposition of P25 NPs during its reduction at the time of hydrothermal treatment. Different analyses confirmed that GO was successfully incorporated into the electrospun nylon-6 fibers and simultaneous reduction of GO as well as deposition of P25 NPs on the surface of fibers was possible during hydrothermal treatment. The photoactive property of the as-prepared nanocomposites was tested against methylene blue. The results showed that P25-RGO/nylon-6 nanocomposite mat is more effective than the TiO2/nylon-6 electrospun composite mat. The water flux at a given pressure of different mats was measured to find out the filter efficiency of the membranes. The as-prepared composite mat has great potentiality as an economically–friendly water filter media and reusable photocatalyst.
Pant, HR, Pant, B, Sharma, RK, Amarjargal, A, Kim, HJ, Park, CH, Tijing, LD & Kim, CS 2013, 'Antibacterial and photocatalytic properties of Ag/TiO2/ZnO nano-flowers prepared by facile one-pot hydrothermal process', Ceramics International, vol. 39, no. 2, pp. 1503-1510.
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In this paper, a simple and efficient strategy of one-pot synthesis of Ag doped TiO2/ZnO photocatalyst was developed using hydrothermal process. Simultaneous crystallization of Ag and ZnO crystals from their precursor solution containing P25 (TiO2) NPs could form effectively bonded Ag/TiO2/ZnO composite photocatalyst during hydrothermal treatment. Several analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR spectroscopy, and photoluminescence spectroscopy have been used to characterize the resulting Ag/TiO2/ZnO photocatalyst. Results showed that ZnO nano-flowers doped with TiO2 and Ag NPs were formed by this simple facile one-step process. The unique properties of Ag NPs on binary semiconductor composite not only provide the decreased rate of electron-hole separation but also prevent from the loss of photocatalyst during recovery due to the fixed attachment of Ag and TiO2 NPs on the surface of flower shaped large ZnO particles. Therefore, as-synthesized composite is an economically and environmentally friendly photocatalyst. © 2012 Elsevier Ltd and Techna Group S.r.l.
Pant, HR, Park, CH, Pokharel, P, Tijing, LD, Lee, DS & Kim, CS 2013, 'ZnO micro-flowers assembled on reduced graphene sheets with high photocatalytic activity for removal of pollutants', Powder Technology, vol. 235, pp. 853-858.
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In this paper, a simple and efficient strategy was developed for preparing flower-shaped ZnO doped reduced graphene oxide (RGO) composite material by simultaneous crystal growth (of ZnO) and reduction (of graphene oxide) using hydrothermal process. Several analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy have been used to characterize the resulting ZnO/RGO photocatalyst. Results showed that highly crystalline ZnO nano-flowers were effectively doped on the surface of RGO sheets. The unique properties of RGO sheets not only provide the decreased rate of electron–hole separation in ZnO but also prevent from the loss of photocatalyst during recovery due to the fixed attachment of ZnO NPs on the surface of high aspect ratio graphene sheets. Therefore, as-synthesized composite is an economically and environmentally friendly photocatalyst.
Pant, HR, Risal, P, Park, CH, Tijing, LD, Jeong, YJ & Kim, CS 2013, 'Core–shell structured electrospun biomimetic composite nanofibers of calcium lactate/nylon-6 for tissue engineering', Chemical Engineering Journal, vol. 221, pp. 90-98.
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In this work, core-shell structured nylon-6/lactic acid (LA) nanofibers have been produced via single-spinneret electrospinning from the simple blending of LA and nylon-6 solution. The low evaporation rate and plasticizer property of LA was found to be responsible for the formation of point-bonded morphology whereas solvent degradation of nylon-6 with complex phase separation mechanism could give spider-wave-like architecture of the mat and core–shell structure of the composite fibers. The core–shell nanostructure and existence of LA on the shell layer of the fiber were confirmed by TEM and XPS analysis. These fibers were further treated with calcium base to convert surface LA into calcium lactate (CL) which could increase the biocompatibility of composite mat. The SBF incubation test not only confirmed the nucleation capacity of CL to accelerate the deposition of calcium compound on the surface of nanofibers but also facileated the formation of hollow calcium phosphate particles at biomimetic conditions. The adhesion, viability and proliferation properties of osteoblast cells on the composite nanofibers were analyzed by in vitro cell compatibility test. This study demonstrated the non-cytotoxic behavior and good proliferation capacity of calcium lactate/nylon-6 (CL/nylon-6) composite mat. Therefore, the novel nanofibrous composite mat may become a potential candidate for bone tissue engineering
Pant, HR, Risal, P, Park, CH, Tijing, LD, Jeong, YJ & Kim, CS 2013, 'Synthesis, characterization, and mineralization of polyamide-6/calcium lactate composite nanofibers for bone tissue engineering', Colloids and Surfaces B: Biointerfaces, vol. 102, pp. 152-157.
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Park, C-H, Kang, S-J, Tijing, LD, Pant, HR & Kim, CS 2013, 'Inductive heating of electrospun Fe2O3/polyurethane composite mat under high-frequency magnetic field', Ceramics International, vol. 39, no. 8, pp. 9785-9790.
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Park, CH, Kim, C-H, Pant, HR, Tijing, LD, Yu, MH, Kim, Y & Kim, CS 2013, 'An angled robotic dual-nozzle electrospinning set-up for preparing PU/PA6 composite fibers', Textile Research Journal, vol. 83, no. 3, pp. 311-320.
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This paper presents the design and development of a robust electrospinning set-up for the processing of polymer composites at the nanoscale. A robotic-controlled movable dual-nozzle (keeping the rotating collector at a fixed position) set-up with two power supplies is presented for nanocomposite electrospinning. We studied the effect of different angles between two nozzles on the physicochemical properties of composite PU/PA6 electrospun mats obtained from this electrospining set-up. Scanning electron microscopy (SEM) images of the mats indicated that the diameter of the nanofibers and their evenness was affected by the angle between the nozzles. The effect of angle (between the nozzles) on the mechanical strength of the composite mats was also evaluated. The hybrid mat obtained from the dual- nozzle system was found to be mechanically stronger than the individual fibrous mat. Furthermore, the mechanical strength of the composite mat could be increased by decreasing the angle between the tips of the nozzles.
Park, C-H, Tijing, LD, Pant, HR, Kim, T-H, Amarjargal, A, Kim, HJ & Kim, CS 2013, 'Accelerated in vitro durability testing of nonvascular Nitinol stents based on the electrical potential sensing method', Applied Physics A, vol. 112, no. 4, pp. 919-926.
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Petrou, K, Jimenez-Denness, I, Chartrand, K, McCormack, C, Rasheed, M & Ralph, PJ 2013, 'Seasonal heterogeneity in the photophysiological response to air exposure in two tropical intertidal seagrass species', MARINE ECOLOGY PROGRESS SERIES, vol. 482, pp. 93-106.
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Photosynthesis, chlorophyll a fluorescence, leaf bio-optical properties and pigments were measured in 2 tropical intertidal seagrass species, Zostera muelleri ssp. capricorni and Halophila ovalis before, during and after air-exposure over a tidal cycle. Data were collected across 4 seasons (October and January-growing seasons; May and July-senescent seasons) to determine seasonal dynamics in physiological responses to air exposure. Both species showed clear light-dependent responses with a decline in photosynthetic efficiency and increased photoprotection during periods of combined maximum daily irradiance and air exposure for all seasons. In Z. muelleri ssp. capricorni there was a negative correlation between air-exposed effective quan - tum yield and light intensity, suggesting exposure was driving this decline. Conversely, sensitivity (decline in effective quantum yield of photosystem II) to increased irradiance dominated the response in H. ovalis, with no change in the magnitude of this response between air-exposed and submerged blades. The response to air exposure observed in Z. muelleri ssp. capricorni showed seasonal variation, with a greater decline in photosynthesis during the spring (October). Tidal exposure did not provide intertidal seagrasses a 'window' of photosynthetic respite (increase in photosynthesis) from high natural or anthropogenic turbidity. However, the periods immediately prior to and after exposure were important for providing an optimum period for net photosynthetic gain. © Inter-Research 2013.
Phuntsho, S, Hong, S, Elimelech, M & Shon, HK 2013, 'Forward osmosis desalination of brackish groundwater: Meeting water quality requirements for fertigation by integrating nanofiltration', JOURNAL OF MEMBRANE SCIENCE, vol. 436, no. 1, pp. 1-15.
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The concept of fertiliser drawn forward osmosis (FDFO) desalination lies in the premise that fertilisers that serve as draw solutions (DS) add value to the FDFO product water for fertigation. However, because FDFO desalination is concentration based, the process cannot continue beyond the concentration equilibrium, one of the major limitations of the forward osmosis (FO) process. This results in final FDFO product water that, unless subjected to substantial dilution with fresh water, exceeds the acceptable nutrient concentrations for direct fertigation. In this study, nanofiltration (NF) has been assessed as an integrated process to FDFO desalination, either as a pre-treatment or post-treatment, to reduce the nutrient concentrations in the final product water and thereby allow direct use of the product water for fertigation without further dilution. NF as pre-treatment or post-treatment was found effective in reducing the nutrient concentrations using brackish groundwater (BGW) sources with relatively low total dissolved solid (TDS). However, when using higher TDS BGW sources, the product water still required further dilution or post-treatment before fertigation. NF as post-treatment was found to be more advantageous both in terms of reduced nutrient concentrations in the final product water and energy consumption. © 2013 Elsevier B.V.
Phuntsho, S, Kim, J, Lotfi, F & Shon, HK 2013, 'MONO/DI-ammonium phosphate fertilizers as draw solutions for forward osmosis desalination', IDA Journal of Desalination and Water Reuse, vol. 5, no. 1, pp. 34-39.
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Forward osmosis (FO) can be suitably used to desalinate water for irrigation using fertilizer as draw agent due to the desalinated water containing diluted draw solution. Mono-ammonium hydrogen phosphate (MAP) and di-ammonium hydrogen phosphate (DAP) are the important group of the most concentrated soluble fertilizer materials containing both N and P, essential fertilizer elements needed by the plants. The comparative assessment of these two fertilizers as draw solution (DS) for FO desalination was conducted. The results indicate that both MAP and DAP can be used as a DS for FO desalination and for direct fertigation although concentration polarization significantly affected the water flux. MAP performed slightly better in terms of pure water flux. However, the performance ratio of DAP was comparable to MAP when saline feed water was used. Furthermore, DAP was seen as a better DS candidate for desalination and fertigation due to significantly lower reverse solute flux.
Phuntsho, S, Sahebi, S, Majeed, T, Lotfi, F, Kim, JE & Shon, HK 2013, 'Assessing the major factors affecting the performances of forward osmosis and its implications on the desalination process', CHEMICAL ENGINEERING JOURNAL, vol. 231, pp. 484-496.
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This study evaluates the influence of some of the major factors affecting the performances of forward osmosis (FO) desalination and assessed their potential implications on the overall process. The major factors assessed include membrane properties, draw solution (DS) properties, feed solution (FS) properties and the operating conditions. The influence of the membrane properties was evaluated using three types of membranes and in doing so we have also introduced one newly synthesized proprietary thin film composite FO (TFC-FO) membrane. The performances of TFC-FO membrane in terms of water flux and reverse solute flux were significantly higher than the commercial cellulose triacetate FO membrane and TFC reverse osmosis membrane in FO process. Although adequate osmotic pressure of DS is desirable for FO process, the influence of DS osmotic pressure was less significant at higher DS osmotic pressure and therefore selecting an optimum initial osmotic pressure is essential for FO process to minimize pumping energy. A critical DS concentration has been hypothesized to minimize the implications of DS concentrations on the capital and operational cost of the FO desalination plant. Total dissolved solids (TDS) of the FS play a significant role in the performance of FO process however the influence of feed TDS was less significant for feed higher than 20,000. mg/L indicating that FO has a promising potential for use with high TDS feed water. Although, water flux decreased, the reverse solute flux (RSF) and specific RSF also decreased slightly at higher feed TDS. For operating parameters, the influence of crossflow velocity and the crossflow direction was also investigated. © 2013 Elsevier B.V.
Rahman, SMA, Masjuki, HH, Kalam, MA, Abedin, MJ, Sanjid, A & Sajjad, H 2013, 'Impact of idling on fuel consumption and exhaust emissions and available idle-reduction technologies for diesel vehicles – A review', Energy Conversion and Management, vol. 74, pp. 171-182.
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Rahman, SMA, Masjuki, HH, Kalam, MA, Abedin, MJ, Sanjid, A & Sajjad, H 2013, 'Production of palm and Calophyllum inophyllum based biodiesel and investigation of blend performance and exhaust emission in an unmodified diesel engine at high idling conditions', Energy Conversion and Management, vol. 76, pp. 362-367.
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Raj Pant, H, Pant, B, Joo Kim, H, Amarjargal, A, Hee Park, C, Tijing, LD, Kyo Kim, E & Sang Kim, C 2013, 'A green and facile one-pot synthesis of Ag–ZnO/RGO nanocomposite with effective photocatalytic activity for removal of organic pollutants', Ceramics International, vol. 39, no. 5, pp. 5083-5091.
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In this study, Ag-ZnO/reduced graphene oxide (Ag-ZnO/RGO) composite was synthesized by a green and facile one-step hydrothermal process. Aqueous suspension containing Ag and ZnO precursors with graphene oxide (GO) sheets was heated at 140 °C for 2 h. The morphology and structure of as-synthesized particles were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and Photoluminescence (PL) spectroscopy which revealed the formation of composite of metal, metal oxide and RGO. It was observed that the presence of Ag precursor and GO sheets in the hydrothermal solution could sufficiently decrease the size of ZnO flowers. The hybrid nanostructure, with unique morphology, obtained from this convenient method (low temperature, less time, and less number of reagents) was found to have good photocatalytic and antibacterial activity. The perfect recovery of catalyst after reaction and its unchanged efficiency for cyclic use showed that it will be an economically and environmentally friendly photocatalyst. © 2012 Elsevier Ltd and Techna Group S.r.l.
Ran, NHM, Yuliati, L, Lee, SL, Mahlia, TMI & Nur, H 2013, 'Liquid–gas boundary catalysis by using gold/polystyrene-coated hollow titania', Journal of Colloid and Interface Science, vol. 394, pp. 490-497.
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Rizwanul Fattah, IM, Masjuki, HH, Liaquat, AM, Ramli, R, Kalam, MA & Riazuddin, VN 2013, 'Impact of various biodiesel fuels obtained from edible and non-edible oils on engine exhaust gas and noise emissions', Renewable and Sustainable Energy Reviews, vol. 18, pp. 552-567.
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Ruelo, MTG, Tijing, LD, Amarjargal, A, Park, C-H, Kim, HJ, Pant, HR, Lee, DH & Kim, CS 2013, 'Assessing the effect of catalytic materials on the scaling of carbon steel', Desalination, vol. 313, pp. 189-198.
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The present study investigated the efficacy of catalytic materials, i.e., tourmaline, zinc and aluminum, in mitigating calcium carbonate scaling of carbon steel material. Artificial hard water (480 ± 20 mg/l) was used to re-circulate in the system loop for 3 days of fouling test. Tests were carried out at various solution temperatures (27, 40, and 70 °C) and flow rates (800, 1200, and 1600 ml/min). Different measurements and characterization methods were carried out. The results showed consistently lower deposition of scales when the catalytic materials were incorporated in the system (i.e., treatment case), with as much as 21% reduction compared to the no-treatment case, depending on the solution temperature and flow rate. There was more corrosion activity observed in the no-treatment case compared to the treatment case. Furthermore, the scales at the no-treatment case showed pointed, sea-urchin-like structure, while those of the treatment case were dull, star-like structures and with thicker crystals than those at no-treatment case. In this study, we have shown the potential of catalytic materials in reducing scaling formation on non-heated carbon steel surface.
Sackett, O, Petrou, K, Reedy, B, De Grazia, A, Hill, R, Doblin, M, Beardall, J, Ralph, P & Heraud, P 2013, 'Phenotypic Plasticity of Southern Ocean Diatoms: Key to Success in the Sea Ice Habitat?', PLOS ONE, vol. 8, no. 11.
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Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseudo-nitzschia subcurvata) exhibited phenotypic plasticity in response to salinity and temperature regimes experienced during the seasonal formation and decay of sea ice. The degree of phenotypic plasticity, in terms of changes in macromolecular composition, was highly species-specific and consistent with each species' known distribution and abundance throughout sea ice, meltwater and pelagic habitats, suggesting that phenotypic plasticity may have been selected for by the extreme variability of the polar marine environment. We argue that changes in diatom macromolecular composition and shifts in species dominance in response to a changing climate have the potential to alter nutrient and energy fluxes throughout the Southern Ocean ecosystem. © 2013 Sackett et al.
Sanjid, A, Masjuki, HH, Kalam, MA, Rahman, SMA, Abedin, MJ & Palash, SM 2013, 'Impact of palm, mustard, waste cooking oil and Calophyllum inophyllum biofuels on performance and emission of CI engine', Renewable and Sustainable Energy Reviews, vol. 27, pp. 664-682.
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Shafie, SM, Mahlia, TMI & Masjuki, HH 2013, 'Life cycle assessment of rice straw co-firing with coal power generation in Malaysia', Energy, vol. 57, pp. 284-294.
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Shahabuddin, M, Liaquat, AM, Masjuki, HH, Kalam, MA & Mofijur, M 2013, 'Ignition delay, combustion and emission characteristics of diesel engine fueled with biodiesel', Renewable and Sustainable Energy Reviews, vol. 21, pp. 623-632.
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Shahabuddin, M, Masjuki, HH & Kalam, MA 2013, 'Experimental Investigation into Tribological Characteristics of Bio-Lubricant Formulated from Jatropha Oil', Procedia Engineering, vol. 56, pp. 597-606.
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Shahabuddin, M, Masjuki, HH, Kalam, MA, Bhuiya, MMK & Mehat, H 2013, 'Comparative tribological investigation of bio-lubricant formulated from a non-edible oil source (Jatropha oil)', Industrial Crops and Products, vol. 47, pp. 323-330.
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Shekarchian, M, Zarifi, F, Moghavvemi, M, Motasemi, F & Mahlia, TMI 2013, 'Energy, exergy, environmental and economic analysis of industrial fired heaters based on heat recovery and preheating techniques', Energy Conversion and Management, vol. 71, pp. 51-61.
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Shon, HK, Phuntsho, S, Chaudhary, DS, Vigneswaran, S & Cho, J 2013, 'Nanofiltration for water and wastewater treatment – a mini review', Drinking Water Engineering and Science Discussions, vol. 6, no. 1, pp. 59-77.
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Abstract. The application of membrane technology in water and wastewater treatment is increasing due to stringent water quality standards. Nanofiltration (NF) is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination. NF has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This paper briefly reviews the application of NF for water and wastewater treatment including fundamentals of membrane process in general, mechanisms of NF process including few basic models. fouling challenges and their control mechanisms adopted.
Shon, HK, Phuntsho, S, Chaudhary, DS, Vigneswaran, S & Cho, J 2013, 'Nanofiltration for water and wastewater treatment – a mini review', Drinking Water Engineering and Science, vol. 6, no. 1, pp. 47-53.
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Abstract. The application of membrane technology in water and wastewater treatment is increasing due to stringent water quality standards. Nanofiltration (NF) is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination. NF has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This paper briefly reviews the application of NF for water and wastewater treatment including fundamentals, mechanisms, fouling challenges and their controls.
Silakhori, M, Naghavi, M, Metselaar, H, Mahlia, T, Fauzi, H & Mehrali, M 2013, 'Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage', Materials, vol. 6, no. 5, pp. 1608-1620.
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Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.
Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC & Chong, WT 2013, 'Experimental study on performance and exhaust emissions of a diesel engine fuelled with Ceiba pentandra biodiesel blends', Energy Conversion and Management, vol. 76, pp. 828-836.
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Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC, Atabani, AE & Chong, WT 2013, 'A global comparative review of biodiesel production from jatropha curcas using different homogeneous acid and alkaline catalysts: Study of physical and chemical properties', Renewable and Sustainable Energy Reviews, vol. 24, pp. 514-533.
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Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC, Chong, WT & Boosroh, MH 2013, 'Overview properties of biodiesel diesel blends from edible and non-edible feedstock', Renewable and Sustainable Energy Reviews, vol. 22, pp. 346-360.
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Silitonga, AS, Ong, HC, Mahlia, TMI, Masjuki, HH & Chong, WT 2013, 'Characterization and production of Ceiba pentandra biodiesel and its blends', Fuel, vol. 108, pp. 855-858.
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Silitonga, AS, Ong, HC, Masjuki, HH, Mahlia, TMI, Chong, WT & Yusaf, TF 2013, 'Production of biodiesel from Sterculia foetida and its process optimization', Fuel, vol. 111, pp. 478-484.
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Simon, A, McDonald, JA, Khan, SJ, Price, WE & Nghiem, LD 2013, 'Effects of caustic cleaning on pore size of nanofiltration membranes and their rejection of trace organic chemicals', Journal of Membrane Science, vol. 447, pp. 153-162.
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Sinutok, S, Hill, R, Doblin, MA & Ralph, PJ 2013, 'Diurnal photosynthetic response of the motile symbiotic benthic foraminiferan Marginopora vertebralis', MARINE ECOLOGY PROGRESS SERIES, vol. 478, pp. 127-138.
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Movement of the symbiont-bearing foraminiferan Marginopora vertebralis and photo physiological response to diurnal fluctuations in irradiance were investigated in field and laboratory experiments. The abundance of M. vertebralis from both light-exposed and sheltered habitats was determined 5 times during the day, from pre-dawn to post-dusk. M. vertebralis abundance was significantly higher in sheltered compared to exposed habitats at midday under high irradiance, and this movement enabled the algal symbionts to avoid excessive photoinhibition. The diurnal changes in photosynthetic efficiency were not consistent with the typical midday solar maximum downregulation of photosystem II observed in other photoautotrophs and was likely due to the negatively phototactic capacity of the foraminifera. To confirm the light-dependent movement of foraminifera, individuals in exposed and sheltered habitats were exposed to the photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU) in the laboratory. The lack of movement in DCMU-exposed specimens confirmed light-dependent movement and subsequent disruption of signalling between the host foraminiferan and the algal symbionts. Analysis of chlorophyll and xanthophyll pigments, as well as symbiont density, indicated that under high irradiance, foraminiferal symbionts have the capacity to reduce light stress by activating photoprotective mechanisms. The negatively phototactic behaviour prevented chlorophyll degradation, symbiont loss and bleaching, suggesting that it is the primary mechanism for controlling light exposure in these foraminifera. This behaviour provides a competitive advantage over other sessile organisms in avoiding photoinhibition and bleaching by moving away from over-saturating irradiance, towards less damaging light fields. © Inter-Research 2013.
Sleap, SB, Turner, BD, Krabbenhøft, K & Sloan, SW 2013, 'Effects of pCO2 on the Removal of Fluoride from Wastewater by Calcite', Journal of Environmental Engineering, vol. 139, no. 8, pp. 1053-1061.
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Su, K, Ni, B & Yu, H 2013, 'Modeling and optimization of granulation process of activated sludge in sequencing batch reactors', Biotechnology and Bioengineering, vol. 110, no. 5, pp. 1312-1322.
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AbstractAerobic granulation is a promising process for wastewater treatment, but this granulation process is very complicated and is affected by many factors. Thus, a mathematical model to quantitatively describe such a granulation process is highly desired. In this work, by taking into account all of key steps including biomass growth, increase in particle size and density, detachment, breakage and sedimentation, an one‐dimensional mathematic model was developed to simulate the granulation process of activated sludge in a sequencing batch reactor (SBR). Discretization methodology was applied by dividing operational time, sedimentation process, size fractions and slices into discretized calculation elements. Model verification and prediction for aerobic granulation process were conducted under four different conditions. Four parameters indicative of granulation progression, including mean radius, biomass discharge ratio, total number, and bioparticle size distribution, were predicted well with the model. An optimum controlling strategy, automatically adjusted of settling time, was also proposed based on this model. Moreover, aerobic granules with a density higher than 120 g VSS/L and radius in a range of 0.4–1.0 mm were predicted to have both high settling velocity and substrate utilization rate, and the corresponding optimum operating conditions were be determined. Experimental results demonstrate that the developed model is appropriate for simulating the formation of aerobic granules in SBRs. These results are useful for designing and optimizing the cultivation and operation of aerobic granule process. Biotechnol. Bioeng. 2013; 110: 1312–1322. © 2012 Wiley Periodicals, Inc.
Surawski, NC, Miljevic, B, Bodisco, TA, Brown, RJ, Ristovski, ZD & Ayoko, GA 2013, 'Application of Multicriteria Decision Making Methods to Compression Ignition Engine Efficiency and Gaseous, Particulate, and Greenhouse Gas Emissions', ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 47, no. 4, pp. 1904-1912.
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Compression ignition (CI) engine design is subject to many constraints, which present a multicriteria optimization problem that the engine researcher must solve. In particular, the modern CI engine must not only be efficient but must also deliver low gaseous, particulate, and life cycle greenhouse gas emissions so that its impact on urban air quality, human health, and global warming is minimized. Consequently, this study undertakes a multicriteria analysis, which seeks to identify alternative fuels, injection technologies, and combustion strategies that could potentially satisfy these CI engine design constraints. Three data sets are analyzed with the Preference Ranking Organization Method for Enrichment Evaluations and Geometrical Analysis for Interactive Aid (PROMETHEE-GAIA) algorithm to explore the impact of (1) an ethanol fumigation system, (2) alternative fuels (20% biodiesel and synthetic diesel) and alternative injection technologies (mechanical direct injection and common rail injection), and (3) various biodiesel fuels made from 3 feedstocks (i.e., soy, tallow, and canola) tested at several blend percentages (20-100%) on the resulting emissions and efficiency profile of the various test engines. The results show that moderate ethanol substitutions (∼20% by energy) at moderate load, high percentage soy blends (60-100%), and alternative fuels (biodiesel and synthetic diesel) provide an efficiency and emissions profile that yields the most 'preferred' solutions to this multicriteria engine design problem. Further research is, however, required to reduce reactive oxygen species (ROS) emissions with alternative fuels and to deliver technologies that do not significantly reduce the median diameter of particle emissions. © 2013 American Chemical Society.
Tabatabaiefar, SHR, Fatahi, B & Samali, B 2013, 'Lateral seismic response of building frames considering dynamic soil-structure interaction effects', STRUCTURAL ENGINEERING AND MECHANICS, vol. 45, no. 3, pp. 311-321.
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In this study, to have a better judgment on the structural performance, the effects of dynamic Soil-Structure Interaction (SSI) on seismic behaviour and lateral structural response of mid-rise moment resisting building frames are studied using Finite Difference Method. Three types of mid-rise structures, including 5, 10, and 15 storey buildings are selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee, according to Australian Standard AS 1170.4. The above mentioned frames have been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction), and (ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural lateral displacements and drifts for the above mentioned boundary conditions have been compared and discussed. It is concluded that the dynamic soil-structure interaction plays a considerable role in seismic behaviour of mid-rise building frames including substantial increase in the lateral deflections and inter-storey drifts and changing the performance level of the structures from life safe to near collapse or total collapse. Thus, considering soil-structure interaction effects in the seismic design of mid-rise moment resisting building frames, particularly when resting on soft soil deposit, is essential.
Tabatabaiefar, SHR, Fatahi, B & Samali, B 2013, 'Seismic Behavior of Building Frames Considering Dynamic Soil-Structure Interaction', INTERNATIONAL JOURNAL OF GEOMECHANICS, vol. 13, no. 4, pp. 409-420.
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The seismic excitation experienced by structures is a function of the earthquake source, travel path effects, local site effects, and soilstructure interaction (SSI) influences. The result of the first three of these factors is referred to as free-field ground motion. The structural response to free-field motion is influenced by the SSI. In particular, accelerations within structures are affected by the flexibility of the foundation support and variations between the foundation and free-field motions. Consequently, an accurate assessment of inertial forces and displacements in structures can require a rational treatment of SSI effects. In the current study, to depict these effects on the seismic response of moment-resisting building frames, a 10-story moment-resisting building frame resting on a shallow foundation was selected in conjunction with three soil types with shear-wave velocities of less than 600 m/s, representing Soil Classes Ce, De, and Ee according to an existing Australian Standard. The structural sections were designed after applying dynamic nonlinear time-history analysis, based on both the elastic method, and inelastic procedure using the elastic-perfectly plastic behavior of the structural elements. The frame sections were modeled and analyzed using the finite-difference method andthe FLAC 2D software under two different boundary conditions: (1) fixed-base (no SSI) and (2) considering the SSI. Fully nonlinear dynamic analysis under the influence of various earthquake records was conducted and the results of the two different cases for elastic and inelastic behavior of the structuralmodel were extracted, compared, and discussed. The results indicate that the performance level of themodel resting on Soil Class Ce does not change substantially and remains in the life safe level while the performance level of themodel resting on Soil Classes De and Ee substantially increase from the life safe level to near collapse for both elastic and ine...
Tadkaew, N, McDonald, J, Khan, SJ & Nghiem, LD 2013, 'Effects of salinity on the removal of trace organic contaminants by membrane bioreactor treatment for water reuse', Desalination and Water Treatment, vol. 51, no. 25-27, pp. 5164-5171.
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Tahan Latibari, S, Mehrali, M, Mehrali, M, Indra Mahlia, TM & Cornelis Metselaar, HS 2013, 'Synthesis, characterization and thermal properties of nanoencapsulated phase change materials via sol–gel method', Energy, vol. 61, pp. 664-672.
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Tijing, L, Ruelo, M, Park, C-H, Amarjargal, A, Kim, H, Pant, H, Lee, D-H & Kim, C 2013, 'Efficacy of zinc and tourmaline in mitigating corrosion of carbon steel in non-flow mode', Chemical Papers, vol. 67, no. 10, pp. 1304-1310.
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AbstractLaboratory corrosion immersion tests were carried out to investigate the effectiveness of a physical water treatment (PWT) using zinc and ceramic tourmaline-based catalytic materials for the control of carbon steel corrosion in acidic still water (i.e., pH 4.5–5). The tests were carried out at different water temperatures over 168 h. Our results showed a maximum of 22 % reduction in the corrosion rate using PWT in comparison with the control case. Furthermore, the corrosion products depicted more agglomerated particles after the PWT treatment. In both cases, differences were observed in the crystal structures, showing in general lower corrosion activity when PWT was used. The present results could find potential applications in water distribution systems and where metallic materials are exposed to stagnant acidic water.
Tijing, LD, Amarjargal, A, Jiang, Z, Ruelo, MTG, Park, C-H, Pant, HR, Kim, D-W, Lee, DH & Kim, CS 2013, 'Antibacterial tourmaline nanoparticles/polyurethane hybrid mat decorated with silver nanoparticles prepared by electrospinning and UV photoreduction', Current Applied Physics, vol. 13, no. 1, pp. 205-210.
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Tijing, LD, Choi, W, Jiang, Z, Amarjargal, A, Park, C-H, Pant, HR, Im, I-T & Kim, CS 2013, 'Two-nozzle electrospinning of (MWNT/PU)/PU nanofibrous composite mat with improved mechanical and thermal properties', Current Applied Physics, vol. 13, no. 7, pp. 1247-1255.
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Tijing, LD, Park, C-H, Choi, WL, Ruelo, MTG, Amarjargal, A, Pant, HR, Im, I-T & Kim, CS 2013, 'Characterization and mechanical performance comparison of multiwalled carbon nanotube/polyurethane composites fabricated by electrospinning and solution casting', Composites Part B: Engineering, vol. 44, no. 1, pp. 613-619.
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Multiwalled carbon nanotube/polyurethane (MWNT/PU) composites were prepared by electrospinning and solution casting. The morphological and thermal properties, and mechanical performance of the nanofiber and film composites were characterized and compared. The tensile strength of neat PU film was 9-fold higher than that of neat PU nanofibrous mat. The incorporation of MWNTs increased the tensile strength and modulus of the composite nanofibers by 69% and 140%, respectively, and 62% and 78%, respectively for composite films. The MWNT/PU composites showed an improved thermal degradation behavior, with the incorporation of low MWNT content in the composites.
Tijing, LD, Park, C-H, Kang, S-J, Amarjargal, A, Kim, T-H, Pant, HR, Kim, HJ, Lee, DH & Kim, CS 2013, 'Improved mechanical properties of solution-cast silicone film reinforced with electrospun polyurethane nanofiber containing carbon nanotubes', Applied Surface Science, vol. 264, pp. 453-458.
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Tran, NH, Urase, T, Ngo, HH, Hu, J & Ong, SL 2013, 'Insight into metabolic and cometabolic activities of autotrophic and heterotrophic microorganisms in the biodegradation of emerging trace organic contaminants', BIORESOURCE TECHNOLOGY, vol. 146, no. 1, pp. 721-731.
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Many efforts have been made to understand the biodegradation of emerging trace organic contaminants (EOCs) in the natural and engineered systems. This review summarizes the current knowledge on the biodegradation of EOCs while having in-depth discussion on metabolism and cometabolism of EOCs. Biodegradation of EOCs is mainly attributed to cometabolic activities of both heterotrophic and autotrophic microorganisms. Metabolism of EOCs can only be observed by heterotrophic microbes. Autotrophic ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaeal (AOA) cometabolize a variety of EOCs via the non-specific enzymes, such as ammonia monooxygenase (AMO). Higher biodegradation of EOCs is often noted under nitrification at high ammonia loading rate. The presence of a growth substrate promotes cometabolic biodegradation of EOCs. Potential strategies for enhancing the biodegradation of EOCs were also proposed in this review. © 2013 Elsevier Ltd.
Tu, KL, Chivas, AR & Nghiem, LD 2013, 'Enhanced boron rejection by NF/RO membranes by complexation with polyols: Measurement and mechanisms', Desalination, vol. 310, pp. 115-121.
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Wang, Q, Ye, L, Jiang, G, Jensen, PD, Batstone, DJ & Yuan, Z 2013, 'Free Nitrous Acid (FNA)-Based Pretreatment Enhances Methane Production from Waste Activated Sludge', Environmental Science & Technology, vol. 47, no. 20, pp. 11897-11904.
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Wang, Y-K, Sheng, G-P, Ni, B-J, Li, W-W, Zeng, RJ, Wang, Y-Q, Shi, B-J & Yu, H-Q 2013, 'Simultaneous carbon and nitrogen removals in membrane bioreactor with mesh filter: An experimental and modeling approach', Chemical Engineering Science, vol. 95, pp. 78-84.
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Wijekoon, KC, Fujioka, T, McDonald, JA, Khan, SJ, Hai, FI, Price, WE & Nghiem, LD 2013, 'Removal of N-nitrosamines by an aerobic membrane bioreactor', Bioresource Technology, vol. 141, pp. 41-45.
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Wijekoon, KC, Hai, FI, Kang, J, Price, WE, Guo, W, Ngo, HH & Nghiem, LD 2013, 'The fate of pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides during MBR treatment', BIORESOURCE TECHNOLOGY, vol. 144, pp. 247-254.
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This study examined the relationship between molecular properties and the fate of trace organic contaminants (TrOCs) in the aqueous and solid phases during wastewater treatment by MBR. A set of 29 TrOCs was selected to represent pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides that occur ubiquitously in municipal wastewater. Both adsorption and biodegradation/transformation were found responsible for the removal of TrOCs by MBR treatment. A connection between biodegradation and molecular structure could be observed while adsorption was the dominant removal mechanism for the hydrophobic (logD > 3.2) compounds. Highly hydrophobic (logD > 3.2) but readily biodegradable compounds did not accumulate in sludge. In contrast, recalcitrant compounds with a moderate hydrophobicity, such as carbamazepine, accumulated significantly in the solid phase. The results provide a framework to predict the removal and fate of TrOCs by MBR treatment.
Xie, M, Nghiem, LD, Price, WE & Elimelech, M 2013, 'A Forward Osmosis-Membrane Distillation Hybrid Process for Direct Sewer Mining: System Performance and Limitations', ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 47, no. 23, pp. 13486-13493.
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Xie, M, Nghiem, LD, Price, WE & Elimelech, M 2013, 'Impact of humic acid fouling on membrane performance and transport of pharmaceutically active compounds in forward osmosis', WATER RESEARCH, vol. 47, no. 13, pp. 4567-4575.
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Xie, M, Price, WE, Nghiem, LD & Elimelech, M 2013, 'Effects of feed and draw solution temperature and transmembrane temperature difference on the rejection of trace organic contaminants by forward osmosis', JOURNAL OF MEMBRANE SCIENCE, vol. 438, pp. 57-64.
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Xie, W-M, Ni, B-J, Seviour, T & Yu, H-Q 2013, 'Evaluating the impact of operational parameters on the formation of soluble microbial products (SMP) by activated sludge', Water Research, vol. 47, no. 3, pp. 1073-1079.
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Xu, J, Fu, Q, Ren, JM, Bryant, G & Qiao, GG 2013, 'Novel drug carriers: from grafted polymers to cross-linked vesicles', Chem. Commun., vol. 49, no. 1, pp. 33-35.
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Yan, C, Yang, Y, Zhou, J, Liu, M, Nie, M, Shi, H & Gu, L 2013, 'Antibiotics in the surface water of the Yangtze Estuary: Occurrence, distribution and risk assessment', Environmental Pollution, vol. 175, pp. 22-29.
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The occurrence and distribution of five groups of antibiotics were investigated in the surface water of Yangtze Estuary over four seasons. Of the 20 antibiotics, only sulfamerazine was not detected at all sampling sites, indicating widespread occurrence of antibiotic residues in the study area. Detection frequencies and concentrations of antibiotics were generally higher in January, indicating that low flow conditions and low temperature might enhance the persistence of antibiotics in water. Antibiotic levels varied with location, with the highest concentrations being observed around river discharge and sewage outfall. Furthermore, a positive correlation between total antibiotic and DOC concentrations revealed the significant role played by DOC. Risk assessment based on single compound exposure showed that sulfapyridine and sulfamethoxazole could cause medium risk to daphnid in the Yangtze Estuary. © 2012 Elsevier Ltd. All rights reserved.
Yang, S, Hai, FI, Nghiem, LD, Nguyen, LN, Roddick, F & Price, WE 2013, 'Removal of bisphenol A and diclofenac by a novel fungal membrane bioreactor operated under non-sterile conditions', International Biodeterioration & Biodegradation, vol. 85, pp. 483-490.
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Yang, S, Hai, FI, Nghiem, LD, Price, WE, Roddick, F, Moreira, MT & Magram, SF 2013, 'Understanding the factors controlling the removal of trace organic contaminants by white-rot fungi and their lignin modifying enzymes: A critical review', Bioresource Technology, vol. 141, pp. 97-108.
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Yang, S, Hai, FI, Nghiem, LD, Roddick, F & Price, WE 2013, 'Removal of trace organic contaminants by nitrifying activated sludge and whole-cell and crude enzyme extract of Trametes versicolor', Water Science and Technology, vol. 67, no. 6, pp. 1216-1223.
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The resistance of certain anthropogenic trace organic contaminants (TrOCs) to conventional wastewater treatment and their potential adverse effects on human and ecological health raise significant concerns and have prompted research on their bioremediation by white-rot fungi. This study compared the removal efficiencies of four widespread TrOCs: carbamazepine (CBZ), sulfamethoxazole (SMX), bisphenol A (BPA) and diclofenac (DCF), by nitrifying activated sludge as well as whole-cell and extracellular enzyme (laccase) extract of the white-rot fungus Trametes versicolor. Fungal whole-cell culture removed only BPA and DCF but with high efficiencies (>90%) while the mixed nitrifying culture removed all compounds, although by levels of only 5–40%. Rapid initial sorption on fungal mycelium (44 ± 13% for DCF) was observed; however, biodegradation governed the overall removal. Performance comparison between fungal whole-cell and extracellular extract revealed that, unlike BPA, a catalytic pathway independent of extracellular laccase was responsible for DCF removal. Addition of mediator (1-hydroxybenzotriazole) to extracellular extract improved the removal of SMX which bears an electron donor group, but not that of the resistant compound CBZ.
York, PH, Gruber, RK, Hill, R, Ralph, PJ, Booth, DJ & Macreadie, PI 2013, 'Physiological and Morphological Responses of the Temperate Seagrass Zostera muelleri to Multiple Stressors: Investigating the Interactive Effects of Light and Temperature', PLOS ONE, vol. 8, no. 10.
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Understanding how multiple environmental stressors interact to affect seagrass health (measured as morphological and physiological responses) is important for responding to global declines in seagrass populations. We investigated the interactive effects of temperature stress (24, 27, 30 and 32°C) and shading stress (75, 50, 25 and 0% shade treatments) on the seagrass Zostera muelleri over a 3-month period in laboratory mesocosms. Z. muelleri is widely distributed throughout the temperate and tropical waters of south and east coasts of Australia, and is regarded as a regionally significant species. Optimal growth was observed at 27°C, whereas rapid loss of living shoots and leaf mass occurred at 32°C. We found no difference in the concentration of photosynthetic pigments among temperature treatments by the end of the experiment; however, up-regulation of photoprotective pigments was observed at 30°C. Greater levels of shade resulting in high photochemical efficiencies, while elevated irradiance suppressed effective quantum yield (ΔF/FM'). Chlorophyll fluorescence fast induction curves (FIC) revealed that the J step amplitude was significantly higher in the 0% shade treatment after 8 weeks, indicating a closure of PSII reaction centres, which likely contributed to the decline in ΔF/FM' and photoinhibition under higher irradiance. Effective quantum yield of PSII (ΔF/FM') declined steadily in 32°C treatments, indicating thermal damage. Higher temperatures (30°C) resulted in reduced above-ground biomass ratio and smaller leaves, while reduced light led to a reduction in leaf and shoot density, above-ground biomass ratio, shoot biomass and an increase in leaf senescence. Surprisingly, light and temperature had few interactive effects on seagrass health, even though these two stressors had strong effects on seagrass health when tested in isolation. In summary, these results demonstrate that populations of Z. muelleri in south-eastern Australia are sensitive to...
Zarifi, F, Mahlia, TMI, Motasemi, F, Shekarchian, M & Moghavvemi, M 2013, 'Current and future energy and exergy efficiencies in the Iran’s transportation sector', Energy Conversion and Management, vol. 74, pp. 24-34.
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Zhao, YX, Gao, BY, Qi, QB, Wang, Y, Phuntsho, S, Kim, J-H, Yue, QY, Li, Q & Shon, HK 2013, 'Cationic polyacrylamide as coagulant aid with titanium tetrachloride for low molecule organic matter removal', JOURNAL OF HAZARDOUS MATERIALS, vol. 258, no. 1, pp. 84-92.
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This is the first attempt to use cationic polyacrylamide (PAM) as coagulant aid with titanium tetrachloride (TiCl4) to improve the coagulation performance and floc properties. Coagulation-flocculation treatment was applied to simulated water (with fulvic acid (FA) as model organic matter) for both coagulation behavior investigation and floc characterization. The effect of PAM on floc reformation properties after cyclic breakage/regrowth was also investigated. Ultrafiltration experiments were performed to investigate the influence of PAM aided TiCl4 coagulation on the membrane fouling. The results showed that organic removal was enhanced by PAM addition at low TiCl4 doses. Floc growth rate and floc size were significantly affected by dosing sequence. TiCl4-PAM significantly improved the floc strength factors (Sf) and recovery factors (Rf). The dosing sequence of TiCl4 and PAM significantly influenced the floc structure. Characterization of the flocculated sludge indicated that TiO2 with anatase structure and high photocatalytic activity could be obtained from the TiCl4-PAM flocculated sludge. © 2013 Elsevier B.V.
Zhao, YX, Gao, BY, Shon, HK, Qi, QB, Phuntsho, S, Wang, Y, Yue, QY, Li, Q & Kim, J-H 2013, 'Characterization of coagulation behavior of titanium tetrachloride coagulant for high and low molecule weight natural organic matter removal: The effect of second dosing', CHEMICAL ENGINEERING JOURNAL, vol. 228, no. 1, pp. 516-525.
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A two-stage titanium tetrachloride (TiCl4) dosing strategy is applied for investigating the coagulation effect on simulated water containing humic acid (HA) and fulvic acid (FA) and these represent the dissolved organic matter (DOM). The influence of second TiCl4 dose on coagulation efficiency, flock re-growth and the fractal dimension properties is studied for the beneficial effect of the second coagulant dose. Moreover, the impact of increased shear on the ultra filtration permeate flux in coagulation-ultra filtration (C-UF) hybrid process is explored. A small second dose essentially decreases the residual turbidity and improves the organic matter removal. Also, flocks with larger size and better recoverability result and having more compact structure than those obtained without the second TiCl4 coagulant dose. At the same total TiCl4 coagulant concentrations, the two-stage dosing mode reveals significant advantage over the single coagulant dosing in terms of turbidity removal, flock size and recoverability although organic matter removal and flock compactness degree are more or less deteriorated during the two-stage dosing process. The second TiCl4 dose contributes to larger re-generated flocks with better re-growth ability than those obtained without the second dose within a wide range of high shear rate and even with prolonged breaking period. Two-stage dosing mode could improve the ultra filtration permeate flux under certain shear conditions. An extension in breakage time leads to much severer flux decline than short breakage periods. In case of FA simulated water, the ultra filtration permeate flux was less sensitive to increasing shear rate than in case of HA simulated water. © 2013 Elsevier B.V.
Zhao, YX, Gao, BY, Zhang, GZ, Phuntsho, S, Wang, Y, Yue, QY, Li, Q & Shon, HK 2013, 'Comparative study of floc characteristics with titanium tetrachloride against conventional coagulants: Effect of coagulant dose, solution pH, shear force and break-up period', CHEMICAL ENGINEERING JOURNAL, vol. 233, pp. 70-79.
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Characteristics of flocs formed by titanium tetrachloride (TiCl4), ferric chloride (FeCl3) and aluminum sulfate (Al2(SO4)3) were comparatively investigated in terms of floc growth rate, size, strength, recoverability and fractal dimension in real water treatment. Impacts of coagulant dose, solution pH and hydraulic conditions, including shear force and break-up period, on floc properties were investigated. Results showed that the floc size followed the order of TiCl4FeCl3Al2(SO4)3 within the dose range investigated. The response of floc strength to coagulant dose depended on the coagulant used, while the floc recoverability decreased with the increasing dose regardless of the coagulant used. Within the solution pH range investigated, the floc strength and recoverability showed the following order of Al2(SO4)3FeCl3TiCl4 and those of TiCl4 were the least affected by solution pH. Additionally, the floc strength decayed with the increasing shear force and break-up period for the three coagulants. TiCl4 yielded the flocs with the weakest recoverability within both the shear force and break-up period ranges investigated. Moreover, the floc compactness followed the order of FeCl3TiCl4Al2(SO4)3 under either shear force condition. © 2013 Elsevier Ltd.
Zhao, YX, Phuntsho, S, Gao, BY, Huang, X, Qi, QB, Yue, QY, Wang, Y, Kim, J-H & Shon, HK 2013, 'Preparation and Characterization of Novel Polytitanium Tetrachloride Coagulant for Water Purification', ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 47, no. 22, pp. 12966-12975.
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Polymeric metal coagulants are increasingly being used to improve coagulation efficiency, yet the research on the development of titanium and particularly polytitanium salts remains limited. This study is the first attempt in the synthesis, characterization, and application of polytitanium salts as coagulants. Polytitanium tetrachloride (PTC) solutions with different basicity values B (OH/Ti molar ratio) were prepared using a slow alkaline titration method. Jar tests were conducted to assess coagulation performance using both synthetic and real raw water samples, and the floc characteristics were monitored online using a laser diffraction particle size analyzer. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) was utilized to identify various Ti species, with the results providing strong evidence of the presence of various hydrolyzed Ti species in the titanium aqueous phase. Compared to titanium tetrachloride (TiCl4), higher or comparable turbidity and organic matter removal efficiency could be achieved by PTC with improved floc characteristics in terms of size, growth rate, and structure. Besides, the water pH after PTC coagulation was significantly improved toward neutral pH. This study indicates that PTC is an effective and promising coagulant for water purification. Besides, the PTC flocculated sludge was able to recycle and produce functional TiO2 photocatalyst. © 2013 American Chemical Society.
Zheng, Y, Hou, L, Liu, M, Lu, M, Zhao, H, Yin, G & Zhou, J 2013, 'Diversity, abundance, and activity of ammonia-oxidizing bacteria and archaea in Chongming eastern intertidal sediments', Applied Microbiology and Biotechnology, vol. 97, no. 18, pp. 8351-8363.
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Zulkifli, NWM, Kalam, MA, Masjuki, HH & Yunus, R 2013, 'Experimental Analysis of Tribological Properties of Biolubricant with Nanoparticle Additive', Procedia Engineering, vol. 68, pp. 152-157.
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Zulkifli, NWM, Kalam, MA, Masjuki, HH, Shahabuddin, M & Yunus, R 2013, 'Wear prevention characteristics of a palm oil-based TMP (trimethylolpropane) ester as an engine lubricant', Energy, vol. 54, pp. 167-173.
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Zuthi, M, Ngo, H, Guo, W & Nguyen, TT 2013, 'The effects of biomass parameters on the dissolved organic carbon removal in a sponge submerged membrane bioreactor', World Academy of Science, Engineering and Technology, vol. 78, no. 1, pp. 46-50.
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A novel sponge submerged membrane bioreactor (SSMBR) was developed to effectively remove organics and nutrients from wastewater. Sponge is introduced within the SSMBR as a medium for the attached growth of biomass. This paper evaluates the effects of new and acclimatized sponges for dissolved organic carbon (DOC) removal from wastewater at different mixed liquor suspended solids (MLSS) concentration of the sludge. It was observed in a series of experimental studies that the acclimatized sponge performed better than the new sponge whilst the optimum DOC removal could be achieved at 10g/L of MLSS with the acclimatized sponge. Moreover, the paper analyses the relationships between the MLSSsponge/MLSSsludge and the DOC removal efficiency of SSMBR. The results showed a non-linear relationship between the biomass parameters of the sponge and the sludge, and the DOC removal efficiency of SSMBR. A second-order polynomial function could reasonably represent these relationships.
Zuthi, MFR, Guo, WS, Ngo, HH, Nghiem, LD & Hai, FI 2013, 'Enhanced biological phosphorus removal and its modeling for the activated sludge and membrane bioreactor processes', BIORESOURCE TECHNOLOGY, vol. 139, no. 1, pp. 363-374.
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A modified activated sludge process (ASP) for enhanced biological phosphorus removal (EBPR) needs to sustain stable performance for wastewater treatment to avoid eutrophication in the aquatic environment. Unfortunately, the overall efficiency of the EBPR in ASPs and membrane bioreactors (MBRs) is frequently hindered by different operational/system constraints. Moreover, although phosphorus removal data from several wastewater treatment systems are available, a comprehensive mathematical model of the process is still lacking. This paper presents a critical review that highlights the core issues of the biological phosphorus removal in ASPs and MBRs while discussing the inhibitory process requirements for other nutrients' removal. This mini review also successfully provided an assessment of the available models for predicting phosphorus removal in both ASP and MBR systems. The advantages and limitations of the existing models were discussed together with the inclusion of few guidelines for their improvement. © 2013 Elsevier Ltd.
Zuthi, MFR, Ngo, HH, Guo, WS, Li, JX, Xia, SQ & Zhang, ZQ 2013, 'New proposed conceptual mathematical models for biomass viability and membrane fouling of membrane bioreactor', BIORESOURCE TECHNOLOGY, vol. 142, no. 1, pp. 737-740.
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The production and accumulation of soluble microbial products (SMP), extracellular polymeric substances (EPS) and colloidal inert compounds within a membrane bioreactor (MBR) may greatly affect the biomass viability and subsequently the permeability of the membrane. This paper aims at presenting new mathematical models of biomass viability and membrane fouling that has been conceptually developed through establishing links between these biomass parameters and operating parameters of the MBR. The proposed models can be used to predict the biomass viability and membrane fouling at any state of operation of MBR. Meanwhile, easily measurable parameters of the proposed model can also serve to estimate SMP/EPS concentration in the supernatant of MBR without the tedious and expensive measurement.
Zuthi, MFR, Ngo, HH, Guo, WS, Zhang, J & Liang, S 2013, 'A review towards finding a simplified approach for modelling the kinetics of the soluble microbial products (SMP) in an integrated mathematical model of membrane bioreactor (MBR)', INTERNATIONAL BIODETERIORATION & BIODEGRADATION, vol. 85, no. 1, pp. 466-473.
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Soluble microbial products (SMPs) tend to accumulate in the membrane bioreactor (MBR) systems as a consequence of high membrane rejection and apparently low biodegradability within the wastewater treatment system. The extension of the activated sludge models (ASMs) with SMPs, therefore, has received crucial importance in recent days, particularly considering their potential use as indicators of the membrane fouling propensity. This paper presents a critical review of the formation and degradation kinetics of SMP subdivisions that have so far been used for the mathematical modelling of MBR. The paper identified a simplified approach to incorporate the kinetics of the SMP formation and degradation in the general mathematical models of MBR. It suggested that the inclusion of only four additional linear differential equations in the ASM1-SMP integrated mathematical model could simulate well the effluent quality and membrane fouling prediction. The model would also serve as a useful tool in optimizing operation conditions for better treatability and fouling control.