Beecham, SC, Kandasamy, JK, Khiadani, MH & Trinh, DV 2005, 'Impacts of OSD on Flooding within an Urban Catchment', Journal of Urban Water, vol. 2, no. 1, pp. 23-32.
Chiemchaisri, C, Chiemchaisri, W, Kornboonraksa, T, Dumrongsukit, C, Threedeach, S, Ngo, HH & Vigneswaran, S 2005, 'Particle and microorganism removal in floating plastic media coupled with microfiltration membrane for surface water treatment', WATER SCIENCE AND TECHNOLOGY, vol. 51, no. 10, pp. 93-100.
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Floating plastic media followed by hollow fiber microfiltration membrane was applied for surface water treatment. The performance of the system in terms of particle and microorganisms was investigated. The floating filter was examined at different filtra
Coyne, KJ, Handy, SM, Demir, E, Whereat, EB, Hutchins, DA, Portune, KJ, Doblin, MA & Cary, SC 2005, 'Improved quantitative real-time PCR assays for enumeration of harmful algal species in field samples using an exogenous DNA reference standard', LIMNOLOGY AND OCEANOGRAPHY-METHODS, vol. 3, no. 9, pp. 381-391.
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© 2005, by the American Society of Limnology and Oceanography, Inc. Quantitative real-time PCR (QPCR) is a powerful and sensitive method for quantitative detection of microorganisms. Application of this methodology for enumeration of harmful algal bloom (HAB) species has the potential to revolutionize our approach to HAB research, making it possible to identify correlations between cell abundances and factors that regulate bloom dynamics. Its application to ecological studies, however, has produced mixed results. QPCR assays typically rely on the generation of standard curves from plasmids or laboratory cultures that may be unrealistic when compared to amplification of DNA extracted from field samples. In addition, existing methods often fail to incorporate controls to assess variability in extraction and amplification efficiencies, or include controls that are sequence-specific and preclude the investigation of multiple species. Here, we describe the development and rigorous analysis of QPCR assays for two HAB species, Chattonella subsalsa and Heterosigma akashiwo, in which we introduce a known concentration of exogenous DNA plasmid into the extraction buffer as a reference standard. Since the target DNA is extracted in the presence of the reference standard, inherent variability in extraction and amplification efficiencies affect both target and standard equally. Furthermore, the reference standard is applicable to QPCR analysis of any microbial species. Using environmental bloom samples as calibrators, we evaluated the accuracy of the comparative Ct method for enumeration of target species in several field samples. Our investigation demonstrates that the comparative Ct method with an exogenous DNA reference standard provides both accurate and reproducible quantification of HAB species in environmental samples.
Drake, LA, Meyer, AE, Forsberg, RL, Baier, RE, Doblin, MA, Heinemann, S, Johnson, WP, Koch, M, Rublee, PA & Dobbs, FC 2005, 'Potential invasion of microorganisms and pathogens via 'interior hull fouling': biofilms inside ballast water tanks', BIOLOGICAL INVASIONS, vol. 7, no. 6, pp. 969-982.
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Surfaces submerged in an aquatic milieu are covered to some degree with biofilms - organic matrices that can contain bacteria, microalgae, and protozoans, sometimes including disease-causing forms. One unquantified risk of aquatic biological invatsions is the potential for biofilms within ships' ballast water tanks to harbour pathogens, and, in tuen, seed othe waters. To begin to evaluate this vector, we collected biofilm samples fromtanks' surfaces and deployed controlled-surface sampling units within tanks. We then measured a variety of microbial metrics within the biofilms to test the hypotheses that pathogens are present in biofilms and that biofilms have higher microbial densities compared to ballst water. Field experiments and sampling of coastwise and oceangoing ships arriving at ports in Chesapeake Bay and the North American Great Lakes showed the presence of abundant microorganisms, including pathogens, in biofilms. These results suggest that ballast-tank biofilms represent an additional risk of microbial invasion, provided they release cells into the water or they are sloughed off during normal ballasting operations.
Guo, WS, Shim, WG, Vigneswaran, S & Ngo, HH 2005, 'Effect of operating parameters in a submerged membrane adsorption hybrid system: experiments and mathematical modeling', JOURNAL OF MEMBRANE SCIENCE, vol. 247, no. 1-2, pp. 65-74.
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This study aims at developing a simple and practical mathematical model to predict the performance of a submerged membrane adsorption hybrid system (SMAHS). Adsorption equilibrium and kinetic studies were first carried out with powdered activated carbon (PAC) for removing persisting organics from a synthetic wastewater. A series of short-term SMAHS experiments were conducted with preadsorption at different operating conditions such as aeration rate, backwash frequency, PAC dose and filtration flux. The Talu adsorption equilibrium and homogeneous surface diffusion model (HSDM) described well the isothermal adsorption behavior and adsorption kinetics, respectively. The semi-empirical mathematical model formulated for membrane-adsorption system predicts successfully the performance of SMAHS in terms of total organic carbon (TOC) removal. A coefficient known as 'membrane correlation coefficient (MCC)' introduced in the model was found to be very useful in describing both the adsorption of organics adsorbed onto the PAC and onto the membrane surface, and separation of PAC (with organics adsorbed on it) by the membrane. © 2004 Elsevier B.V. All rights reserved.
Guo, WS, Vigneswaran, S & Ngo, HH 2005, 'Effect of flocculation and/or adsorption as pretreatment on the critical flux of crossflow microfiltration', DESALINATION, vol. 172, no. 1, pp. 53-62.
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This study aims at identifying the effect of pretreatment such as flocculation and/or adsorption on the performance of crossflow microfiltration (CFMF). CFMF performance was studied in terms of critical flux. The results indicated that: (1) flocculation alone as a pretreatment could effectively remove the large molecular weight organic matter from 30,000 to 60,000 Daltons; (2) flocculation, together with adsorption as a pretreatment to CFMF, could remove both large and small molecular weight organics; (3) flocculation as a pretreatment was significantly better than adsorption in improving the critical flux; (4) critical flux increased from 100 L/m2.h to 520 L/m2.h when flocculation-adsorption was applied. The critical flux in long-term experiments was the same as that of the short-term experiments. However, the critical flux slightly decreased (5%) in long-term experiments compared to short-term operation with flocculation and adsorption as a pretreatment. © 2005 Elsevier B.V. All rights reserved.
Handy, SM, Coyne, KJ, Portune, KJ, Demir, E, Doblin, MA, Hare, CE, Cary, SC & Hutchins, DA 2005, 'Evaluating vertical migration behavior of harmful raphidophytes in the Delaware Inland Bays utilizing quantitative real-time PCR', AQUATIC MICROBIAL ECOLOGY, vol. 40, no. 2, pp. 121-132.
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Mixed blooms of 4 species of harmful raphidophytes (Chattonella cf. verruculosa, Chattonella subsalsa, Heterosigma akashiwo, and Fibrocapsa japonica) occur in the shallow (1 ti 2m) Delaware Inland Bays (DIB), USA. Raphidophytes vertically migrate in other deeper water ecosystems to utilise deep nutrient stocks at night, and thus obtain an advantage over non-migrating algae.Anoxic DIB sediments release high levels of bioavailable phosphate, which could potentially be used by vertically migrating flagellates. This study aimed to characterise and understamd the migration oatterns of DIB raphidiphytes, and determine whether benthic phosphate fluxes could provide the cells with P. We demonstrated vertical migration of isolated DIB raphidophyte cultures in the laboratory, where differences inthe response of C. subsalsa and H. akashiwo to light:dark period manipulations suggested possible diffeerneces in external versus endogenous regulation of migration behaviour in the 2 species. Natural blooms in the filed (enclosed in a mesocosm system) also exhibited patterns of diel vertical distributions of each species. Our data suggested that these 2 photoautotrophic species spend daylight hours near the surface and are found directly on the sediment surface at night. However, diel changes in particulate C:P ratios did not support the hypothesis that there is preferential uptake of sedimentary phosphate at night. Our results also suggested that the migration behaviour may have important implications for designing sampling strategies for monitoring programs. QPCR has a number of decisive advantages over traditional microscopic counting methods, making this a poweful tool for fine spatial temporal scale detection and enum,eration of vertically migrating harmful algal species.
Hendra, R, Hamdani, Mahlia, TMI & Masjuki, HH 2005, 'Thermal and melting heat transfer characteristics in a latent heat storage system using mikro', Applied Thermal Engineering, vol. 25, no. 10, pp. 1503-1515.
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Huang, ZG, Guo, ZP, Liu, HK & Dou, SX 2005, 'Effect of Ni content on the structural and electrochemical properties of Mg1.9Cu0.1Niχ alloys', Journal of New Materials for Electrochemical Systems, vol. 8, no. 4, pp. 283-289.
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Mg-based alloys, Mg1.9Cu0.1Niχ (χ = 1.8, 1.9, 2.0, 2.1), were fabricated through high-energy ball milling, and the effects of nickel content on the electrochemical characteristics have been investigated. A high discharge capacity of 490 mAhg-1 was observed for χ = 1.8, compared with 435 mAhg-1 for χ = 2.1. As to capacity degradation, 66.7 % of initial capacity was lost after 15 cycles for χ = 1.8, while only 47.2% for χ = 2.1. Cyclic Voltammograms (CV) indicates that nickel can help maintain redox reaction current and consequently improve the cycle performance. The X-ray mapping analysis indicates that Mg, Ni, and Cu are uniformly distributed in the particles. The O content in the alloy electrodes after 15 cycles decreases with the increase of Ni content in the alloys, suggesting that Ni can efficiently suppress the formation of Mg(OH) 2. The linear polarization curves show that the exchange current density, namely the rate of hydriding/dehydriding, increases from 13 mAg -1 to 133 mAg-1 when the nickel content varies from 1.8 to 2.1. This is also considered as a reason for the observed improved capacity stability. © J. New. Mat. Electrochem. Systems.
Jegatheesan, V & Vigneswaran, S 2005, 'Deep Bed Filtration: Mathematical Models and Observations', Critical Reviews in Environmental Science and Technology, vol. 35, no. 6, pp. 515-569.
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Numerous mathematical models have been developed to evaluate both initial and transient stage removal efficiency of deep bed filters. Microscopic models either using trajectory analysis or convective-diffusion equations were used to compute the initial removal efficiency. These models predicted the removal efficiency under favorable filtration conditions quantitatively, but failed to predict the removal efficiency under unfavorable conditions. They underestimated the removal efficiency under unfavorable conditions. Thus, semi-empirical formulations were developed to compute initial removal efficiencies under unfavorable conditions. Also, correction for the adhesion of particles onto filter grains improved the results obtained for removal efficiency from the trajectory analysis. Macroscopic models were used to predict the transient stage removal efficiency of deep bed filters. The O'Melia and Ali(1) model assumed that the particle removal is due to filter grains as well as the particles that are already deposited onto the filter grain. Thus, semi-empirical models were used to predict the ripening of filtration. Several modifications were made to the model developed by O'Melia and Ali to predict the deterioration of particle removal during the transient stages of filtration. Models considering the removal of particles under favorable conditions and the accumulation of charges on the filter grains during the transient stages were also developed. This article evaluates those models and their applicability under different operating conditions of filtration
Jegatheesan, V, Vigneswaran, S & Lee, S-H 2005, 'Deposition of submicron particles in deep bed filtration under unfavorable surface conditions', Korean Journal of Chemical Engineering, vol. 22, no. 1, pp. 142-146.
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Deterioration in the filter removal efficiency of submicron particles (lambda/lambda(0)) under unfavorable surface conditions is affected by the number of deposited particles per filter grain. In the case of above micron particles, the deterioration of f
Jiang, JQ, Yin, Q, Pearce, P & Zhou, J 2005, 'A survey of endocrine disrupting chemicals in sewage and a preliminary treatment trial', Water Science and Technology, vol. 52, no. 8, pp. 1-7.
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This paper demonstrates that synthetic endocrine disrupting chemicals (EDCs) (e.g. bisphenol-A) and natural EDCs (e.g. estrone and 17β-estradiol) were found in the crude sewage from two sewage treatment works. Conventional biological processes can lower EDC concentrations to several hundred nanograms per litre. Because natural EDCs (e.g. estrone and 17β1-estradiol) have biological activity and an adverse impact on the environment at extremely low concentrations (several tens of nanograms per litre), and because the existing wastewater/sewage treatment processes are not adequate to reduce natural EDC concentrations lower than 100ngL−1, further treatment after conventional biological processes is required. Preliminary trials with ferrate(VI) and electrochemical oxidation processes demonstrated that the former is more effective than the latter in reducing EDC concentrations, and that both the processes can effectively reduce EDCs to very low levels, ranging between 20 and 100ngL−1.
Jiang, JQ, Yin, Q, Zhou, JL & Pearce, P 2005, 'Occurrence and treatment trials of endocrine disrupting chemicals (EDCs) in wastewaters', Chemosphere, vol. 61, no. 4, pp. 544-550.
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This study demonstrates that both synthetic and natural endocrine disrupting chemicals (EDCs) (e.g., bisphenol A, estrone and 17β-estradiol) were found in the crude wastewaters from two wastewater treatment works (WwTWs). Conventional biological processes can lower EDCs concentrations to several tens to hundreds ng l-1. Since natural EDCs (e.g., estrone and 17β-estradiol) have biological activity and adverse impact on the environment at extremely low concentrations (several tens of ng l-1), further treatment after conventional biological processes is required. Preliminary trials with ferrate(VI) and electrochemical oxidation process demonstrated that both processes can effectively reduce EDCs to very low levels, ranging between 10 and 100 ng l-1, but the former is more effective than the latter to reduce COD concentration in wastewater for given studying conditions. © 2005 Elsevier Ltd. All rights reserved.
Kalam, MA & Masjuki, HH 2005, 'Effect of coconut oil-blended fuels on diesel engine wear and lubrication', Lubrication Science, vol. 17, no. 4, pp. 389-402.
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Kalam, MA & Masjuki, HH 2005, 'Recent developments on biodiesel in Malaysia', Journal of Scientific and Industrial Research, vol. 64, no. 11, pp. 920-927.
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This paper presents recent developments on biodiesel production from palm oil, its properties and engine test results to evaluate its performance on diesel engine. The potential of palm diesel to be commercially used depends on its price comparison with diesel fuel and its status of reservation. Increasing cost and pollution effects of fossil diesel fuel can be resolved through producing vegetable oil based fuels such as palm diesel. This paper discusses Malaysian palm diesel as well as global biodiesel status, standardization of biodiesel and their commercial price consideration and various engine test results on aspects of brake power, combustion, emissions, engine wear and lubrication performance.
Kalam, MA, Masjuki, HH, Amalina, MA, Abdesselam, H & Mahlia, TMI 2005, 'CO, HC and NOx Emissions Characteristics of a Retrofitted Bi-fuel Natural Gas Engine', HKIE Transactions, vol. 12, no. 3, pp. 25-30.
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This paper presents the experimental results carried out to evaluate CO, HC and NOx exhaust emissions and performance characteristics of a computer integrated bi-fuel spark ignition engine that has been retrofitted for two fuels namely, gasoline and compressed natural gas (CNG). The ignition point was optimised for CNG through the external device so that the maximum cylinder pressure occurred at similar as gasoline fuel such as between 10 to 10.50 deg crank angles after top dead centre (TDC). The used engine is a 4-cylinder spark ignition engine that has been operated with steady state condition using engine operating software and data acquisition system called CADET6. An eddy current dynamometer was used to measure engine performance characteristics such as engine brake power and fuel consumption and to give load on engine during measuring emission characteristics. Bosch and Bacharach exhaust gas analysers were used to measure emissions gases such as CO, HC and NOx. The performance test was done with full throttle condition and corresponding air-fuel (AFR) was evaluated. The emissions test was done with fixed load condition for both the fuels. The results show that CNG reduces 15% brake power with 15% to 18% reduction in specific fuel consumption (SFC) as compared to gasoline fuel. This is mainly due to the gases nature of CNG fuel. The emissions results show that CNG reduces CO and HC emissions but increases NOx emissions. The details about the emissions and performance results with three way catalytic (TWC) converter have been presented and discussed. The results of this experiment will be used to develop of new dedicated natural gas engines. © 2005 Taylor & Francis Group, LLC.
Liu, R, Wilding, A, Hibberd, A & Zhou, JL 2005, 'Partition of Endocrine-Disrupting Chemicals between Colloids and Dissolved Phase As Determined by Cross-Flow Ultrafiltration', Environmental Science & Technology, vol. 39, no. 8, pp. 2753-2761.
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Cross-flow ultrafiltration (CFUF) was developed first for the isolation of natural colloids and subsequently for determining the partition of selected endocrine-disrupting chemicals (EDCs) between river colloids and dissolved phase. In this study, a 1-kDa Millipore Pellicon 2 cartridge type CFUF system was validated using a range of molecular probes spiked in natural waters. Results show that good retention (>80%) of high molecular weight (HMW, >1 kDa) molecules and low retention of low molecular weight (LMW, <1 kDa) molecules can be achieved at high concentration factor (cf) values in sampling mode or over long time scales in recirculation mode. The interactions between aquatic colloids and EDCs were studied by mixing EDCs, water, and colloids previously isolated by CFUF for a certain duration, followed by the separation of the target compounds between the truly dissolved and colloid-bound phases by CFUF and analysis by gas chromatography-mass spectrometry (GC-MS). The kinetics of EDCs binding to colloids were relatively rapid, reaching equilibrium within 5 min. The mass balance of chosen EDCs through CFUF system was fully investigated, with good recovery for the relatively polar EDCs such as estrone and 17β-estradiol. On the basis of EDC sorption by colloids, the partition coefficient normalized to colloidal organic carbon content (Kcoc) was 8.85 × 103, 1.50 × 104, 8.85 × 10 3, 4.87 × 104, and 1.59 × 104 mL/g for bisphenol A, estrone, 17β-estradiol, 17α-ethynylestradiol, and 16α-hydroxyestrone, respectively, which are comparable with the values reported in the literature. In addition, it has been shown that the K coc values of EDCs were relatively independent of their octanol-water partition coefficient (Kow) values, suggesting the important role of different binding mechanisms other than nonspecific hydrophobic interaction between EDCs and natural colloids. As the CFUF-GC-MS method can be used to quantify very low concentration of pollutants and is n...
Mahlia, TMI, Masjuki, HH, Taha, FM, Rahim, NA & Saidur, R 2005, 'Energy labeling for electric fans in Malaysia', Energy Policy, vol. 33, no. 1, pp. 63-68.
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Mahlia, TMI, Said, MFM, Masjuki, HH & Tamjis, MR 2005, 'Cost-benefit analysis and emission reduction of lighting retrofits in residential sector', Energy and Buildings, vol. 37, no. 6, pp. 573-578.
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Maskaoui, K, Zhou, J-L, Han, Y-L, Hu, Z, Zheng, T-L & Hong, H-S 2005, 'Contamination of soil, leaves and vegetables by polychlorinated biphenyls in Xiamen region, China.', J Environ Sci (China), vol. 17, no. 3, pp. 460-464.
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The paper aimed to identify the primary of polychlorinated biphenyls(PCBs) in the Jiulong River Estuary, investigate the spatial distribution of PCBs contamination in the environment, localize the atmospheric source and evaluate ongoing PCBs emissions by analyzing soil samples collected along the Jiulong River region. In addition, the accumulation of PCBs in the human food chain was quantified by analyzing leaf of orange trees and vegetable samples collected along a gradient of soil/atmospheric contamination moving away from the source. Consequently, the impact on the human health and the ecosystem was quantified, different management options were proposed to reduce this impact and to carry out research on organic contaminants along the Jiulong River and Xiamen region.
Maskaoui, K, Zhou, JL, Zheng, TL, Hong, H & Yu, Z 2005, 'Organochlorine micropollutants in the Jiulong River Estuary and Western Xiamen Sea, China', Marine Pollution Bulletin, vol. 51, no. 8-12, pp. 950-959.
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Organochlorine contaminants including 12 polychlorinated biphenyl (PCB) congeners and 18 insecticides were determined in water, pore water and sediments of the Jiulong River Estuary and Western Xiamen Sea, China. The results showed that the levels of the total PCBs ranged from non-detectable to 1500 ng l -1 in water, from 209 to 3870 ng l-1 in pore water, and from 2.78 to 14.8 ng g-1 dry weight in sediments. Total organochlorine insecticide concentrations were from below the limit of detection to 2480 ng l-1 in water, from 267 to 33400 ng l-1 in pore water, and from 4.22 to 46.3 ng g-1 dry weight in sediments. Concentrations of PCBs and insecticides in pore water were significantly higher than those in surface water, due to the high affinity of these hydrophobic compounds for sediment phase. The PCB congeners with the highest concentrations were CB153, CB180 and CB194, which together accounted for 68-87% of total PCBs in water, pore water and sediment. Among the hexachlorocyclohexane (HCH) compounds, beta-HCH was found to be a major isomer. Analysis of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane (DDT) and its metabolites showed that 1,1-dichloro-2[o-chlorophenyl]-2[p-chlorophenyl]-ethylene (DDE) was dominant in the group. In comparison to a 1998 study in the Western Xiamen Sea, levels of organochlorines were enhanced due probably to recent inputs and changes in sediments. © 2004 Elsevier Ltd. All rights reserved.
Saidur, R, Masjuki, HH & Mahlia, TMI 2005, 'Labeling design effort for household refrigerator-freezers in Malaysia', Energy Policy, vol. 33, no. 5, pp. 611-618.
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Shon, H, Vigneswaran, S, Kim, H, Ngo, H & Park, N 2005, 'Comparison of nanofiltration with flocculation - microfiltration - photocatalysis hybrid system in dissolved organic matter removal', Filtration: International Journal for Filtration and Separation, vol. July, pp. 215-221.
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In this research, a NTR 729HF nanofiltration (NF) membrane was employed to remove synthetic organic matter (SOM) from wastewater. NF alone led to a removal of 92.4% of dissolved organic carbon (DOC). The performance of NF was compared with that of a microfiltration (MF) hybrid system consisting of FeCl3 flocculation, MF and photocatalysis. Flocculation and microfiltration followed by photocatalysis led to more than 96% dissolved organic carbon (DOC) removal. A detailed molecular weight (MW) distribution study of organic matter indicated that the photocatalysis initially breaks the large MW organics and then the small MW organics were removed by a photoreactor process. Flocculation with an optimum dose of FeCl3 (68 mg/L as FeCl3) gave rise to the highest removal of organics including small MW organics. The small MW organics remaining after the treatment of flocculation could successfully be removed by photocatalysis.
Shon, HK, Vigneswaran, S, Ben Aim, R, Ngo, HH, Kim, IS & Cho, J 2005, 'Influence of flocculation and adsorption as pretreatment on the fouling of ultrafiltration and nanofiltration membranes: Application with biologically treated sewage effluent', ENVIRONMENTAL SCIENCE & TECHNOLOGY, vol. 39, no. 10, pp. 3864-3871.
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Membrane fouling is a critical limitation on the application of membranes to wastewater reuse. This work aims to understand the fouling phenomenon which occurs in ultrafiltration (UF; 17500 molecular weight cutoff (MWCO)) and nanofiltration (NF; 250 MWCO) membranes, with and without pretreatment. For this purpose, the molecular weight (MW) distribution of the organics has been used as a parameter to characterize the influent, the permeate, and the foulant on the membrane surface. The variation of foulant concentration on the membrane due to pretreatment of the influent by flocculation and/or adsorption was investigated in detail. With the UF membrane, the peak of the MW distribution of organics in the permeate depended on the pretreatment; for example, the weight-averaged MW (Mw) of 675 without pretreatment shifted down to 314 with pretreatment. In the case of the NF membrane, the Mw of organics in the permeate was 478 (without pretreatment) and 310 (with flocculation followed by adsorption). The Mw of the organics in the foulant on the membrane surface was 513 (UF) and 192 (NF) without pretreatment and 351 (UF) and 183 (NF) after pretreatment with flocculation followed by adsorption, respectively. Without the pretreatment, the foulant concentration was higher on both membranes. The difference was more significant on the UF membrane than on the NF membrane. For both membranes, the flocculation-and-then- adsorption pretreatment proved very effective. © 2005 American Chemical Society.
Shon, HK, Vigneswaran, S, Ngo, HH & Aim, RB 2005, 'Is semi-flocculation effective as pretreatment to ultrafiltration in wastewater treatment?', WATER RESEARCH, vol. 39, no. 1, pp. 147-153.
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Shon, HK, Vigneswaran, S, Ngo, HH & Ben Aim, R 2005, 'Is semi-flocculation effective as pretreatment to ultrafiltration in wastewater treatment?', Water Research, vol. 39, no. 1, pp. 147-153.
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In this study, ferric chloride (FeCl3) flocculation was used as a pretreatment to ultrafiltration (UF) in treating synthetic wastewater containing synthetic organic matter (SOM). The effect of flocculant dose was studied in terms of organic removal and m
Shon, HK, Vigneswaran, S, Ngo, HH & Kim, JH 2005, 'Chemical coupling of photocatalysis with flocculation and adsorption in the removal of organic matter', WATER RESEARCH, vol. 39, no. 12, pp. 2549-2558.
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An experimental investigation was made to study the effects of chemical coupling of flocculation and adsorption with photocatalysis in treating persistent organic pollutants in wastewater. The photocatalysis alone showed initial reverse reaction when tit
Shon, HK, Vigneswaran, S, Ngo, HH, Kim, IS & Ben Aim, R 2005, 'Foulant characterizaiton of the NF-membranes with and without pretreatment of biologically treated wastewater', WATER SCIENCE AND TECHNOLOGY, vol. 51, no. 6-7, pp. 277-284.
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In this study, different pretreatment methods such as ferric chloride (FeCl3) flocculation and powdered activated carbon (PAC) adsorption were evaluated in terms of their capability in removing effluent organic matter (EfOM) and the characteristics of the foulants on the NF membranes. A detailed experiment was conducted with two NF membranes (NTR 729HF with MWCO 700 daltons and LF 10 with MWCO 200 daltons). With pretreatment, the concentration of organic matter on the membranes decreased to 5.67110+3 (NTR 729HF) and 4.94010+3 (LF 10) mg EfOM/cm2 of membrane from 6.37210+3 (NTR 729HF) and 4.97910+3 (LF 10) mg EfOM/cm2 of membrane. The MW of the solute fraction of biologically treated sewage effluent (BTSE) ranged from 250 daltons to about 3573 (the most important being 250-520 daltons). The weight-averaged MW values of the foulants on the NTR 729HF membrane reduced from 304 daltons without pre-treatment to 208 daltons with pretreatment. In the case of EfOM, the small molecules (MW 300 to 500 daltons) are mainly responsible for the membrane fouling. Thus, the MW distribution of organic matter in the effluent and in the foulant can be used as a representative tool to evaluate the efficiency of pretreatment and NF and in the selection of their operating conditions.
Shon, HK, Vigneswaran, S, Ngo, HH, Kim, IS & Ben Aim, R 2005, 'Foulant characterization of the NF membranes with and without pretreatment of biologically treated wastewater', Water Science and Technology, vol. 51, no. 6-7, pp. 277-284.
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In this study, different pretreatment methods such as ferric chloride (FeCl3) flocculation and powdered activated carbon (PAC) adsorption were evaluated in terms of their capability in removing effluent organic matter (EfOM) and the characteristics of the foulants on the NF membranes. A detailed experiment was conducted with two NF membranes (NTR 729HF with MWCO 700 daltons and LF 10 with MWCO 200 daltons). With pretreatment, the concentration of organic matter on the membranes decreased to 5.671×10−3 (NTR 729HF) and 4.940×10−3 (LF 10) mg EfOM/cm2 of membrane from 6.372×10−3 (NTR 729HF) and 4.979×10−3 (LF 10) mg EfOM/cm2 of membrane. The MW of the solute fraction of biologically treated sewage effluent (BTSE) ranged from 250 daltons to about 3573 (the most important being 250–520 daltons). The weight-averaged MW values of the foulants on the NTR 729HF membrane reduced from 304 daltons without pre-treatment to 208 daltons with pretreatment. In the case of EfOM, the small molecules (MW 300 to 500 daltons) are mainly responsible for the membrane fouling. Thus, the MW distribution of organic matter in the effluent and in the foulant can be used as a representative tool to evaluate the efficiency of pretreatment and NF and in the selection of their operating conditions.
Smith, PJ, Vigneswaran, S, Ngo, HH, Ben-Aim, R & Nguyen, H 2005, 'Design of a generic control system for optimising back flush durations in a submerged membrane hybrid reactor', JOURNAL OF MEMBRANE SCIENCE, vol. 255, no. 1-2, pp. 99-106.
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Organic fouling on the membrane can be minimised through powdered activated carbon (PAC) usage in the submerged membrane reactor to adsorb dissolved organic matter and reduce direct organic loading on the membrane. However, fouling cannot be totally alle
Turner, BD, Binning, P & Stipp, SLS 2005, 'Fluoride Removal by Calcite: Evidence for Fluorite Precipitation and Surface Adsorption', Environmental Science & Technology, vol. 39, no. 24, pp. 9561-9568.
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Varman, M, Masjuki, HH & Mahlia, TMI 2005, 'One-watt TV label implementation in Malaysia', International Journal of Regulation and Governance, vol. 5, no. 1, pp. 1-12.
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Many countries, from the US to Australia, are now interested in implementing stand-by power energy label for household appliances, in stages, until the 1-W (watt) target is achieved. TV sets consuming 1-W power are widely available in the developed nations. In a developing country like Malaysia, however, the penetration of 1-W stand-by power TV is very low and unless a mandatory label programme is introduced, the degree of penetration is not likely to rise. This paper attempts to calculate the emission pollutants reduction and the energy savings by implementing the 1-W stand-by power label for TV sets in Malaysia. It is estimated that this effort will enable CO2 (carbon dioxide) emissions reduction of 1477.7 kT (kilo tonnes), NOx (oxides of nitrogen) reduction of 4673.0 tonnes, and CO (carbon monoxide) reduction of 763.7 tonnes in the country during the energy label period of 20 years. Additionally, Malaysia will benefit from energy savings of approximately, 2794.9 GWh (gigawatt hours). © 2005, IOS Press. All rights reserved.
Wan, D, Fu, Q & Huang, J 2005, 'Synthesis of a thermoresponsive shell‐crosslinked 3‐layer onion‐like polymer particle with a hyperbranched polyglycerol core', Journal of Polymer Science Part A: Polymer Chemistry, vol. 43, no. 22, pp. 5652-5660.
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AbstractA novel thermoresponsive shell crosslinked three‐layer onion‐like polymer particles were prepared using hyperbranched polyglycerol (PG) as parents compound, the periphery hydroxyl groups of PG were transformed into trithiocarbonates (SC(S)S) first; then, it was used as chain transfer agent to prepare star‐like block copolymer of N‐isopropyl acrylamide (NIPA) and N,N‐dimethylaminoethyl acrylate (DMA) in sequence via reversible addition fragmentation chain transfer (RAFT) process. Thus, a three‐layer polymer, PG[SC(S)S(DMA)b(NIPA)]n, was obtained. The middle layer of poly(DMA) was then crosslinked with 1,8‐diiodoctane, and the resulting onion‐like three‐layer polymer showed a lower critical solution temperature (LCST) in water because of the outer layer of poly(NIPA). The LCST value only slightly depended on the crosslinking degree. Finally, the SC(S)S were transformed into thiols by sequential treating with sodium borohydride and formic acid; thus, the core molecule was chemically detached from the crosslinked shell and a novel shell crosslinked polymer particle was obtained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5652–5660, 2005
Wilding, A, Liu, R & Zhou, JL 2005, 'Dynamic behaviour of river colloidal and dissolved organic matter through cross-flow ultrafiltration system', Journal of Colloid and Interface Science, vol. 287, no. 1, pp. 152-158.
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Through cross-flow filtration (CFF) with a 1-kDa regenerated cellulose Pellicon 2 module, the ultrafiltration characteristics of river organic matter from Longford Stream, UK, were investigated. The concentration of organic carbon (OC) in the retentate in the Longford Stream samples increased substantially with the concentration factor (cf), reaching approximately 40 mg/L at cf 15. The results of dissolved organic carbon (DOC) and colloidal organic carbon (COC) analysis, tracking the isolation of colloids from river waters, show that 2 mg/L of COC was present in those samples and good OC mass balance (77-101%) was achieved. Fluorescence measurements were carried out for the investigation of retentate and permeate behaviour of coloured dissolved organic materials (CDOM). The concentrations of CDOM in both the retentate and permeate increased with increasing cf, although CDOM were significantly more concentrated in the retentate. The permeation model expressing the correlation between log[CDOM] in the permeate and logcf was able to describe the permeation behaviour of CDOM in the river water with regression coefficients (r2) of 0.94 and 0.98. Dry weight analysis indicated that the levels of organic colloidal particles were from 49 to 71%, and between 29 and 51% of colloidal particles present were inorganic. COC as a percentage of DOC was found to be 10-16% for Longford Stream samples. © 2005 Elsevier Inc. All rights reserved.
Zhang, Y & Zhou, JL 2005, 'Removal of estrone and 17β-estradiol from water by adsorption', Water Research, vol. 39, no. 16, pp. 3991-4003.
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Endocrine disrupting chemicals (EDCs) are the focus of current environment concern, as they can cause adverse health effects in an intact organism, or its progeny, subsequent to endocrine function. The paper reports on the removal of estrone (E1) and 17β-estradiol (E2) from water through the use of various adsorbents including granular activated carbon (GAC), chitin, chitosan, ion exchange resin and a carbonaceous adsorbent prepared from industrial waste. The results show that the kinetics of adsorption were adsorbent and compound-dependent, with equilibration being reached within 2 h for a waste-derived carbonaceous adsorbent to 71 h for an ion-exchange resin for E1, and within 7 h for the waste-derived carbonaceous adsorbent to 125 h for GAC for E2. Of all the adsorbents tested, the carbonaceous adsorbent showed the highest adsorption capacity, with a maximum adsorption constant of 87500 ml/g for E1 and 116000 ml/g for E2. The GAC also had a very high adsorption capacity for the two compounds, with a maximum adsorption constant of 9290 ml/g for E1 and 12200 ml/g for E2. The effects of some fundamental environmental parameters including adsorbent concentration, pH, salinity and the presence of humic acid and surfactant on adsorption were studied. The results show that adsorption capacity of activated carbon was decreased with an increase in adsorbent concentration and by the presence of surfactant and humic acid. The results have demonstrated excellent performance of a waste derived adsorbent in removing E1 and E2 from water, and indicated the potential of converting certain solid waste into useful adsorbents for pollution-control purposes. © 2005 Elsevier Ltd. All rights reserved.
Zhang, Z, Yu, G, Cheng, J, Wang, X, Zhang, F & Zhou, J 2005, 'Carbon isotopic fractionation during photolysis of hexachlorobenzene', Progress in Natural Science, vol. 15, no. 1, pp. 82-88.
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Aslam, MU, Masjuki, HH & Kalam, MA 1970, 'Performance and emissions studies of a car engine fueled with gasoline and CNG', 2005 SPE Asia Pacific Oil and Gas Conference and Exhibition - Proceedings, pp. 543-548.
Guo, W 1970, 'Enhancement of critical flux by pretreatment to a crossflow microfiltration in tertiary wastewater treatment', 1st IWA-ASPIRE Conference & Exhibition, IWA, Singapore.
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In this study, the need of pretreatment of flocculation and adsorption on flux improvement was evaluated in terms of critical flux. Critical flux is defined as the maximum filtration rate, under which the membrane fouling does not occur during operation. The critical flux was experimentally evaluated for crossflow microfiltration (CFMF) with and without the pretreatment using biologically treated sewage effluent from a Sewage Treatment Plant in South Korea. The results indicate that the preflocculation could not enhance significantly the critical flux. However, the preadsorption led to a critical flux of more than 3 times higher than that of wastewater (200 L/m2.h). When both flocculation and adsorption were used as pretreatment, the critical flux was raised up to 1000 L/m2.h. Molecular weight distribution (MWD) analyses on the wastewater before and after pretreatment indicated that flocculation-adsorption as pretreatment was efficient to remove most of organic matter in this wastewater, which contains small and middle range MW molecules (250â780 Daltons). The Scanning Electron microscope (SEM) showed that membrane fouling during the critical flux experiments was mainly due to pore blocking and small particles deposit on the membrane surface.
Guo, W 1970, 'The membrane adsorption hybrid system in wastewater treatment and reuse', The 58th National Congress of Indian Institute of Chemical Engineers (CHEMCON-2005), Indian Institute of Technology (IIT), Delhi, India.
Kalam, MA, Hassan, MH & Mohamad, EN 1970, 'Wear and lubrication characteristics of a multi-cylinder diesel engine using vegetable oil blended fuel', Proceedings of the World Tribology Congress III - WTC 2005.
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Wear and lubrication characteristics of a multi cylinder diesel engine when operated on vegetable oil blended fuels were studied. The blended fuels consisted of 10, 20, 30, 40, and 50% coconut oil (COIL) (in volume basis) with diesel fuel (DF2). The engine was operated for a total period of 600 hr for six fuels. The same lubricating oil equivalent to SAE 40 was used for all the fuels system. Wear metals, contaminant elements increased with increasing COIL with DF2. An increasing COIL in blends reduced additive elements; and the reduction rate during blends of ≤ 30% COIL was quite similar to DF2. Soot and sulfation reduced with increasing COIL in blended fuels due to reducing aromatics and sulfur in comparison to DP2. The water concentration increased from above 30% COIL blended fuels. The TBN and viscosity changes were almost normal. The engine did not have any starting and combustion noise problems when operating on COIL blended fuels. This is an abstract of a paper presented at the World Tribology Congress III (Washington, DC 9/12-16/2005).
Kalam, MA, Hassan, MH & Mohamad, EN 1970, 'Wear and Lubrication Characteristics of a Multi-Cylinder Diesel Engine Using Vegetable Oil Blended Fuel', World Tribology Congress III, Volume 2, World Tribology Congress III, ASMEDC.
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This paper presents experimental results carried out to evaluate wear and lubrication characteristics of a multi cylinder diesel engine when operated on vegetable oil blended fuels. The blended fuels consist of 10%, 20%, 30%, 40% and 50% coconut oil (COIL) (in volume basis) with diesel fuel (DF2). Pure DF2 was used for comparison purposes. The engine was operated at constant speed of 2000 rpm with 50% throttle load for a period of 100 hours for each test fuel. The engine was operated for a total period of 600 hours for six fuels. The same lubricating oil equivalent to SAE 40 was used for all the fuels system. The sample of lube oil was collected through a one way valve connected to the crankcase sump at 50 hour intervals. The first sample was collected immediately after the engine had warmed up. The effect of blended fuel on engine component wear and lubrication characteristics in terms of viscosity, total base number (TBN), moisture content, oxidation, wear metals, contaminant elements and lubricant additive depletions were analyzed. The results showed that wear metals, contaminant elements increase with increasing COIL with DF2. An increasing COIL in blends reduces additive elements; and the reduction rate during blends of up to 30% COIL is quite similar to DF2. Soot and sulfation reduce with increasing COIL in blended fuels due to reducing aromatics and sulfur in comparison to DF2. The water concentration increases from above 30% COIL blended fuels. The TBN and viscosity changes are found almost normal. The engine did not have any starting and combustion noise problems when operating on COIL blended fuels. These lubricating oil analysis data will help to select tribological components and compatible lubricating oil for coconut oil or biofuel operated diesel engines.
Kalam, MA, Hassan, MH, Hamlaoui, A, Muhammad Afifi, AB, Mahlia, TMI & Uddin, MA 1970, 'Development of Co-Relation Between Vehicle and Stationary Dynamometer-Engine Emissions', ASME 2005 Internal Combustion Engine Division Spring Technical Conference, ASME 2005 Internal Combustion Engine Division Spring Technical Conference, ASMEDC, Chicago, IL, pp. 101-106.
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This paper presents experimental results carried out to develop co-relation and comparison between vehicle and stationary dynamometer-engine emissions with same engines specifications and brands. The dynamometer-engine has been setup with same load and speed as the vehicle’s engine which is carried on the road. The vehicle’s road load power carried by engine has been calculated and used in this investigation. The stationary engine’s rotational speed has been converted to linear distance to compare specific fuel consumptions (SFC) with real specific fuel consumption (SFC) of the vehicle on the road. The vehicle has been run on road test at 70km/h, 90 km/h and 100 km/h for 100 km each time to measure fuel consumption. Beside this, both the engine and vehicle have been operated in idling condition to measure fuel consumption, CO and HC emissions. Proton vehicle with magma engine (4 cylinders) has been used in this investigation. Both the engine and vehicle have been retrofitted for two fuels namely gasoline fuel and compressed natural gas (CNG). An eddy current dynamometer model Froude Consine (model AG150) is used to test the engine. All the electronic equipment, together with its manipulative controls and indicators such as thermocouples are mounted on ‘CP Cadet10 (UK)’ engine control unit. The engine control unit can control any speed and load applied to the dynamometer-engine. An autocheck model (974/5) and Bacharach model CA300NSX analyzers (standard version, k-type probe) have been used to measure the concentration CO and HC emissions. The results of this investigation will be used to predict the emissions and fuel consumption for road vehicles from stationary dynamometer–engine test.
Kalam, MA, Masjuki, HH, Amalina, MA, Abdesselam, H, Mahlia, TMI & Aslam, MU 1970, 'Emission Characteristics of a Modified CNG Gasoline-Cycle Engine', All Days, SPE Asia Pacific Oil and Gas Conference and Exhibition, SPE, pp. 549-557.
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Abstract This paper presents the experimental results carried out to evaluate the exhaust emissions and performance evaluation of a computer integrated bi-fuel spark ignition engine that has been retrofitted for two fuels namely compressed natural gas (CNG) and base fuel gasoline, operations under steady state with lean burn condition. The used engine was a Proton Magma 4-cylinders spark ignition engine. The emission results such as CO, HC and NOx were measured and compared between the above two fuels. A locally produced three way catalytic converter (TWC) consisting of platinum (Pt), palladium (Pd), cerium oxide (CeO2) and rhodium (Rh) was used to assess the emissions. The CeO2 was used in TWC as an oxygen storage capacity (OSC) to enhance the oxidation process for CO and HC oxidations.
Liu, RX, Zhou, JL & Wilding, A 1970, 'Dynamic behaviour of endocrine disrupting chemicals in the aquatic environment', Proceedings of the 9th International Conference on Environmental Science and Technology, Vol A - Oral Presentations, Pts A and B, 9th International Conference on Environmental Science and Technology, UNIV AEGEAN, Rhodes Isl, GREECE, pp. A885-A890.
Varman, M, Faizul, MS, Masjuki, HH, Kalam, MA & Mahlia, TMI 1970, 'Study of lubricant viscosity from a diesel engine operating on various percentages of coconut oil blended fuel', Proceedings of the World Tribology Congress III - 2005, pp. 861-862.
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In this study, the lubricant viscosity from a diesel engine operating on various percentages of coconut oil blended fuel is investigated to determine the suitable mixture appropriate for a diesel engine. The coconut oil was blended with conventional diesel fuel at an amount varying from ten to fifty percent. The lubricant used in this study is the conventional commercially available lubricant (SAE 40). After proper blending of diesel with coconut oil, the blended fuels are loaded into the fuel tank. The engine is operated at half throttle setting running at 1600 rpm for 100 hours. At every ten hour interval, one lubricant sample was collected and analyzed using a viscometer at 100 °C and 40 °C. The results show that the viscosity for all the blended fuel remain about constant throughout the 100 hours test. However, fifty percent coconut oil blended fuel at 40 °C shows slightly lower viscosity level in comparison to other percentages of blended fuel system. It is expected this is due to high fuel dilution in lube oil. As a result, ten to thirty percent coconut oil blended fuels seems suitable for diesel engine because it's able to prolong lubricant life span by maintaining its viscosity. Copyright © 2005 by ASME.
Varman, M, Faizul, MS, Masjuki, HH, Kalam, MA & Mahlia, TMI 1970, 'Study of Lubricant Viscosity From Diesel Engine Operating on Various Percentages of Coconut Oil Blended Fuel', World Tribology Congress III, Volume 1, World Tribology Congress III, ASMEDC.
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In this study, the lubricant viscosity from a diesel engine operating on various percentages of coconut oil blended fuel is investigated to determine the suitable mixture appropriate for a diesel engine. The coconut oil was blended with conventional diesel fuel at an amount varying from ten to fifty percent. The lubricant used in this study is the conventional commercially available lubricant (SAE 40). After proper blending of diesel with coconut oil, the blended fuels are loaded into the fuel tank. The engine is operated at half throttle setting running at 1600 rpm for 100 hours. At every ten hour interval, one lubricant sample was collected and analyzed using a viscometer at 100 °C and 40 °C. The results show that the viscosity for all the blended fuel remain about constant throughout the 100 hours test. However, fifty percent coconut oil blended fuel at 40 °C shows slightly lower viscosity level in comparison to other percentages of blended fuel system. It is expected this is due to high fuel dilution in lube oil. As a result, ten to thirty percent coconut oil blended fuels seems suitable for diesel engine because it’s able to prolong lubricant life span by maintaining its viscosity.
Zhang, YP & Zhou, JL 1970, 'Removal of estrone and 17B-estradiol from water and wastewater by adsorption and photo degradation', PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON ENVIRONMENTAL SCIENCE AND TECHNOLOGY, VOL A - ORAL PRESENTATIONS, PTS A AND B, 9th International Conference on Environmental Science and Technology, UNIV AEGEAN, Rhodes Isl, GREECE, pp. A1686-A1691.
Zhou, JL, King, AJ & Readman, JW 1970, 'Speciation of polycyclic aromatic hydrocarbons in sediment interstitial water', Proceedings of the 9th International Conference on Environmental Science and Technology, Vol A - Oral Presentations, Pts A and B, 9th International Conference on Environmental Science and Technology, UNIV AEGEAN, Rhodes Isl, GREECE, pp. A1692-A1697.