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Long D. Nghiem - One of the best experts on this subject based on the ideXlab platform.
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trace Organic Contaminant rejection by aquaporin forward osmosis membrane transport mechanisms and membrane stability
Water Research, 2018Co-Authors: Long D. Nghiem, Chuyang Y Tang, Stephen GrayAbstract:Abstract We investigated transport mechanisms of trace Organic Contaminants (TrOCs) through aquaporin thin-film composite forward osmosis (FO) membrane, and membrane stability under extreme conditions with respect to TrOC rejections. Morphology and surface chemistry of the aquaporin membrane were characterised to identify the incorporation of aquaporin vesicles into membrane active layer. Pore hindrance model was used to estimate aquaporin membrane pore size as well as to describe TrOC transport. TrOC transport mechanisms were revealed by varying concentration and type of draw solutions. Experimental results showed that mechanism of TrOC transport through aquaporin-embedded FO membrane was dominated by solution-diffusion mechanism. Non-ionic TrOC rejections were molecular-weight dependent, suggesting steric hindrance mechanisms. On the other hand, ionic TrOC rejections were less sensitive to molecular size, indicating electrostatic interaction. TrOC transport through aquaporin membrane was also subjected to retarded forward diffusion where reverse draw solute flux could hinder the forward diffusion of feed TrOC solutes, reducing their permeation through the FO membrane. Aquaporin membrane stability was demonstrated by either heat treatment or ethanol solvent challenges. Thermal stability of the aquaporin membrane was manifested as a relatively unchanged TrOC rejection before and after the heat treatment challenge test. By contrast, ethanol solvent challenge resulted in a decrease in TrOC rejection, which was evident by the disappearance of the lipid tail of the aquaporin vesicles from infrared spectrum and a notable decrease in the membrane pore size.
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biological performance and trace Organic Contaminant removal by a side stream ceramic nanofiltration membrane bioreactor
International Biodeterioration & Biodegradation, 2016Co-Authors: Hop V Phan, James A Mcdonald, Takahiro Fujioka, William E Price, Stuart J. Khan, Long D. NghiemAbstract:Abstract This study evaluated the performance of a side-stream ceramic nanofiltration membrane bioreactor (NF-MBR) system with respect to basic water quality parameters as well as trace Organic Contaminant (TrOC) removal efficiency. The results show a stable biological performance of the continuous NF-MBR system with high effluent quality (total Organic carbon −1 and NH 4 + –N below the detection limit). Significantly higher performance by this NF-MBR in comparison to the conventional microfiltration/ultrafiltration MBR regarding the removal of a large number of TrOCs was observed. TrOC removal efficiency depended on their hydrophobicity and molecular features. All hydrophobic compounds (Log D pH=6 > 3) were well removed (>85%), except diazinon (59 ± 7%). Hydrophilic compounds containing electron donating groups were also well removed (>90%). By contrast, hydrophilic compounds containing electron withdrawing groups were poorly removed (8–54%). Most of the 40 TrOCs investigated in this study did not accumulate in the sludge. Only three hydrophobic compounds, namely amitriptyline, triclosan and triclocarban showed considerable accumulation in sludge (>500 ng g −1 ). Mass balance indicated biodegradation/transformation as the most significant TrOC removal mechanism by this NF-MBR.
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bacterial community dynamics in an anoxic aerobic membrane bioreactor impact on nutrient and trace Organic Contaminant removal
International Biodeterioration & Biodegradation, 2016Co-Authors: Hop V Phan, William E Price, Jinguo Kang, Ren Zhang, Long D. NghiemAbstract:Abstract The bacterial community in different redox regimes of an anoxic-aerobic MBR under different operating conditions was investigated using pyrosequencing. With internal recirculation (IR) between the anoxic and aerobic reactors, the bacterial communities in these reactors were highly similar in structure and phylogenetic relationship, indicating IR as a key driving force shaping the bacterial communities that are responsible for the core function in the system. Without IR, each redox condition sustained the growth of distinct bacterial communities according to their oxygen requirement, and the anoxic community presented a low capacity of nutrient and trace Organic Contaminant (TrOC) removal. Higher bacterial diversity under longer sludge retention time (SRT) was evident; however, except for a few TrOCs, removal efficiency of TOC, TN and TrOCs were the same irrespective of the SRT. The presence of TrOCs induced shifts in bacterial communities, and a correlation between bacterial communities and TrOC transformation was noted. The important candidates for TrOC biotransformation were the taxa within Proteobacteria , particularly Methylophilales and Myxococcales . Other bacterial groups potentially contributing to TrOC biotransformation were those related to nitrogen removal, such as Rhodocyclales and Plantomycetes . In contrast, the detected members of Cytophagaceae ( Bacteroidetes ) appeared not to contribute to TrOC biotransformation.
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effects of hypochlorite exposure on morphology and trace Organic Contaminant rejection by nf ro membranes
Membrane Water Treatment, 2014Co-Authors: Alexander Simon, Long D. NghiemAbstract:The impacts of membrane degradation due to chlorine attack on the rejection of inOrganic salts and trace Organic Contaminants by nanofiltration (NF) and reverse osmosis (RO) membranes were investigated in this study. The rejection of trace Contaminants was examined at environmentally relevant concentrations. Changes in the membrane surface morphology were observed as a result of chlorine exposure. A small increase in rejection was consistently observed with all four membranes selected in this study after being exposed to a low concentration of hypochlorite (100 ppm). In contrast, a higher concentration of hypochlorite (i.e., 2000 ppm) could be detrimental to the membrane separation capacity. Membranes with severe chlorine impact showed a considerable decrease in rejection over filtration time, possibly due to rearrangement of the polyamide chains under the influence of chlorine degradation and filtration pressure. The reported results indicate that loose NF membranes are more sensitive to chlorine exposure than RO membranes. The impact of hypochlorite exposure (both positive and negative) on rejection is dependent on the strength of the hypochlorite solution and is more significant for the neutral carbamazepine compound than the negatively charged sulfamethoxazole. Disciplines Engineering | Science and Technology Studies Publication Details Simon, A. & Nghiem, L. D. (2014). Effects of hypochlorite exposure on morphology and trace Organic Contaminant rejection by NF/RO membranes. Membrane Water Treatment, 5 (4), 235-250. This journal article is available at Research Online: http://ro.uow.edu.au/eispapers/3108
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simultaneous nitrification denitrification and trace Organic Contaminant troc removal by an anoxic aerobic membrane bioreactor mbr
Bioresource Technology, 2014Co-Authors: Hop V Phan, William E Price, Jinguo Kang, Ren Zhang, Andreas Broeckmann, Long D. NghiemAbstract:Abstract Simultaneous nitrification/denitrification and trace Organic Contaminant (TrOC) removal during wastewater treatment by an integrated anoxic–aerobic MBR was examined. A set of 30 compounds was selected to represent TrOCs that occur ubiquitously in domestic wastewater. The system achieved over 95% total Organic carbon (TOC) and over 80% total nitrogen (TN) removal. In addition, 21 of the 30 TrOCs investigated here were removed by over 90%. Low oxidation reduction potential (i.e., anoxic/anaerobic) regimes were conducive to moderate to high (50% to 90%) removal of nine TrOCs. These included four pharmaceuticals and personal care products (primidone, metronidazole, triclosan, and amitriptyline), one steroid hormone (17β-estradiol-17-acetate), one industrial chemical (4-tert-octylphenol) and all three selected UV filters (benzophenone, oxybenzone, and octocrylene). Internal recirculation between the anoxic and aerobic bioreactors was essential for anoxic removal of remaining TrOCs. A major role of the aerobic MBR for TOC, TN, and TrOC removal was observed.
Turki M Alaboud - One of the best experts on this subject based on the ideXlab platform.
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chemical coagulation based processes for trace Organic Contaminant removal current state and future potential
Journal of Environmental Management, 2012Co-Authors: Jonathan T Alexander, Turki M AlaboudAbstract:Abstract Trace Organic Contaminants have become an increasing cause of concern for governments and water authorities as they attempt to respond to the potential challenges posed by climate change by implementing sustainable water cycle management practices. The augmentation of potable water supplies through indirect potable water reuse is one such method currently being employed. Given the uncertainty surrounding the potential human health impacts of prolonged ingestion of trace Organic Contaminants, it is vital that effective and sustainable treatment methods are utilized. The purpose of this article is to provide a comprehensive literature review of the performance of the chemical coagulation process in removing trace Organic Contaminants from water. This study evaluated the removal data collated from recent research relating to various trace Organic Contaminants during the coagulation process. It was observed that there is limited research data relating to the removal of trace Organic Contaminants using coagulation. The findings of this study suggest that there is a gap in the current research investigating the potential of new types of coagulants and exploring coagulation-based hybrid processes to remove trace Organic Contaminants from water. The data analysed in this study regarding removal efficiency suggests that, even for the significantly hydrophobic compounds, hydrophobicity is not the sole factor governing removal of trace Organic Contaminants by coagulation. This has important implications in that the usual practice of screening coagulants based on turbidity (suspended solid) removal proves inadequate in the case of trace Organic Contaminant removal.
Hop V Phan - One of the best experts on this subject based on the ideXlab platform.
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biological performance and trace Organic Contaminant removal by a side stream ceramic nanofiltration membrane bioreactor
International Biodeterioration & Biodegradation, 2016Co-Authors: Hop V Phan, James A Mcdonald, Takahiro Fujioka, William E Price, Stuart J. Khan, Long D. NghiemAbstract:Abstract This study evaluated the performance of a side-stream ceramic nanofiltration membrane bioreactor (NF-MBR) system with respect to basic water quality parameters as well as trace Organic Contaminant (TrOC) removal efficiency. The results show a stable biological performance of the continuous NF-MBR system with high effluent quality (total Organic carbon −1 and NH 4 + –N below the detection limit). Significantly higher performance by this NF-MBR in comparison to the conventional microfiltration/ultrafiltration MBR regarding the removal of a large number of TrOCs was observed. TrOC removal efficiency depended on their hydrophobicity and molecular features. All hydrophobic compounds (Log D pH=6 > 3) were well removed (>85%), except diazinon (59 ± 7%). Hydrophilic compounds containing electron donating groups were also well removed (>90%). By contrast, hydrophilic compounds containing electron withdrawing groups were poorly removed (8–54%). Most of the 40 TrOCs investigated in this study did not accumulate in the sludge. Only three hydrophobic compounds, namely amitriptyline, triclosan and triclocarban showed considerable accumulation in sludge (>500 ng g −1 ). Mass balance indicated biodegradation/transformation as the most significant TrOC removal mechanism by this NF-MBR.
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bacterial community dynamics in an anoxic aerobic membrane bioreactor impact on nutrient and trace Organic Contaminant removal
International Biodeterioration & Biodegradation, 2016Co-Authors: Hop V Phan, William E Price, Jinguo Kang, Ren Zhang, Long D. NghiemAbstract:Abstract The bacterial community in different redox regimes of an anoxic-aerobic MBR under different operating conditions was investigated using pyrosequencing. With internal recirculation (IR) between the anoxic and aerobic reactors, the bacterial communities in these reactors were highly similar in structure and phylogenetic relationship, indicating IR as a key driving force shaping the bacterial communities that are responsible for the core function in the system. Without IR, each redox condition sustained the growth of distinct bacterial communities according to their oxygen requirement, and the anoxic community presented a low capacity of nutrient and trace Organic Contaminant (TrOC) removal. Higher bacterial diversity under longer sludge retention time (SRT) was evident; however, except for a few TrOCs, removal efficiency of TOC, TN and TrOCs were the same irrespective of the SRT. The presence of TrOCs induced shifts in bacterial communities, and a correlation between bacterial communities and TrOC transformation was noted. The important candidates for TrOC biotransformation were the taxa within Proteobacteria , particularly Methylophilales and Myxococcales . Other bacterial groups potentially contributing to TrOC biotransformation were those related to nitrogen removal, such as Rhodocyclales and Plantomycetes . In contrast, the detected members of Cytophagaceae ( Bacteroidetes ) appeared not to contribute to TrOC biotransformation.
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simultaneous nitrification denitrification and trace Organic Contaminant troc removal by an anoxic aerobic membrane bioreactor mbr
Bioresource Technology, 2014Co-Authors: Hop V Phan, William E Price, Jinguo Kang, Ren Zhang, Andreas Broeckmann, Long D. NghiemAbstract:Abstract Simultaneous nitrification/denitrification and trace Organic Contaminant (TrOC) removal during wastewater treatment by an integrated anoxic–aerobic MBR was examined. A set of 30 compounds was selected to represent TrOCs that occur ubiquitously in domestic wastewater. The system achieved over 95% total Organic carbon (TOC) and over 80% total nitrogen (TN) removal. In addition, 21 of the 30 TrOCs investigated here were removed by over 90%. Low oxidation reduction potential (i.e., anoxic/anaerobic) regimes were conducive to moderate to high (50% to 90%) removal of nine TrOCs. These included four pharmaceuticals and personal care products (primidone, metronidazole, triclosan, and amitriptyline), one steroid hormone (17β-estradiol-17-acetate), one industrial chemical (4-tert-octylphenol) and all three selected UV filters (benzophenone, oxybenzone, and octocrylene). Internal recirculation between the anoxic and aerobic bioreactors was essential for anoxic removal of remaining TrOCs. A major role of the aerobic MBR for TOC, TN, and TrOC removal was observed.
Joan Garcia - One of the best experts on this subject based on the ideXlab platform.
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emerging Organic Contaminant removal in a full scale hybrid constructed wetland system for wastewater treatment and reuse
Ecological Engineering, 2015Co-Authors: Cristina Avila, Josep M Bayona, Isabel Martin, J J Salas, Joan GarciaAbstract:A full-scale hybrid constructed wetland (CW) system based on three stages of different wetlands configurations showed to be a very robust ecotechnology for domestic wastewater treatment and reuse in small communities. It consisted of a 317-m(2) vertical subsurface flow (VF), a 229-m(2) horizontal subsurface flow (HF), and a 240-m(2) free water surface (FWS) CWs operating in series. VF and HF wetlands were planted with Phragmites australis and the FWS contained a mixture of plant species. An excellent overall treatment performance was exhibited on the elimination of conventional water quality parameters (98-99% average removal efficiency for TSS, BOD5 and NH4-N; n = 8), and its final effluent proved to comply with existing Spanish regulations for various reuse applications. The removal of studied emerging Contaminants, which included various pharmaceuticals, personal care products and endocrine disruptors, was also very high (above 80% for all compounds), being compound dependent (n = 8). The high rates were achieved due to high temperatures as well as the differing existing physico-chemical conditions occurring at different CW configurations, which would allow for the combination and synergy of various abiotic/biotic removal mechanisms to occur (e.g. biodegradation, sorption, volatilization, hydrolysis, photodegradation). While aerobic metabolic pathways and solids retention are enhanced in the VF bed, other removal mechanisms such as anaerobic biodegradation and sorption would predominate in the HF bed. At last, photodegradation through direct sunlight exposure, and less importantly, sorption onto Organic matter, seem to take an active part in Organic Contaminant removal in the FWS wetland. (C) 2014 Elsevier B.V. All rights reserved.
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emerging Organic Contaminant removal in a full scale hybrid constructed wetland system for wastewater treatment and reuse
Ecological Engineering, 2015Co-Authors: Cristina Avila, Josep M Bayona, Isabel Martin, J J Salas, Joan GarciaAbstract:Abstract A full-scale hybrid constructed wetland (CW) system based on three stages of different wetlands configurations showed to be a very robust ecotechnology for domestic wastewater treatment and reuse in small communities. It consisted of a 317-m2 vertical subsurface flow (VF), a 229-m2 horizontal subsurface flow (HF), and a 240-m2 free water surface (FWS) CWs operating in series. VF and HF wetlands were planted with Phragmites australis and the FWS contained a mixture of plant species. An excellent overall treatment performance was exhibited on the elimination of conventional water quality parameters (98–99% average removal efficiency for TSS, BOD5 and NH4–N; n = 8), and its final effluent proved to comply with existing Spanish regulations for various reuse applications. The removal of studied emerging Contaminants, which included various pharmaceuticals, personal care products and endocrine disruptors, was also very high (above 80% for all compounds), being compound dependent (n = 8). The high rates were achieved due to high temperatures as well as the differing existing physico-chemical conditions occurring at different CW configurations, which would allow for the combination and synergy of various abiotic/biotic removal mechanisms to occur (e.g. biodegradation, sorption, volatilization, hydrolysis, photodegradation). While aerobic metabolic pathways and solids retention are enhanced in the VF bed, other removal mechanisms such as anaerobic biodegradation and sorption would predominate in the HF bed. At last, photodegradation through direct sunlight exposure, and less importantly, sorption onto Organic matter, seem to take an active part in Organic Contaminant removal in the FWS wetland.
Josep M Bayona - One of the best experts on this subject based on the ideXlab platform.
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emerging Organic Contaminant removal in a full scale hybrid constructed wetland system for wastewater treatment and reuse
Ecological Engineering, 2015Co-Authors: Cristina Avila, Josep M Bayona, Isabel Martin, J J Salas, Joan GarciaAbstract:A full-scale hybrid constructed wetland (CW) system based on three stages of different wetlands configurations showed to be a very robust ecotechnology for domestic wastewater treatment and reuse in small communities. It consisted of a 317-m(2) vertical subsurface flow (VF), a 229-m(2) horizontal subsurface flow (HF), and a 240-m(2) free water surface (FWS) CWs operating in series. VF and HF wetlands were planted with Phragmites australis and the FWS contained a mixture of plant species. An excellent overall treatment performance was exhibited on the elimination of conventional water quality parameters (98-99% average removal efficiency for TSS, BOD5 and NH4-N; n = 8), and its final effluent proved to comply with existing Spanish regulations for various reuse applications. The removal of studied emerging Contaminants, which included various pharmaceuticals, personal care products and endocrine disruptors, was also very high (above 80% for all compounds), being compound dependent (n = 8). The high rates were achieved due to high temperatures as well as the differing existing physico-chemical conditions occurring at different CW configurations, which would allow for the combination and synergy of various abiotic/biotic removal mechanisms to occur (e.g. biodegradation, sorption, volatilization, hydrolysis, photodegradation). While aerobic metabolic pathways and solids retention are enhanced in the VF bed, other removal mechanisms such as anaerobic biodegradation and sorption would predominate in the HF bed. At last, photodegradation through direct sunlight exposure, and less importantly, sorption onto Organic matter, seem to take an active part in Organic Contaminant removal in the FWS wetland. (C) 2014 Elsevier B.V. All rights reserved.
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emerging Organic Contaminant removal in a full scale hybrid constructed wetland system for wastewater treatment and reuse
Ecological Engineering, 2015Co-Authors: Cristina Avila, Josep M Bayona, Isabel Martin, J J Salas, Joan GarciaAbstract:Abstract A full-scale hybrid constructed wetland (CW) system based on three stages of different wetlands configurations showed to be a very robust ecotechnology for domestic wastewater treatment and reuse in small communities. It consisted of a 317-m2 vertical subsurface flow (VF), a 229-m2 horizontal subsurface flow (HF), and a 240-m2 free water surface (FWS) CWs operating in series. VF and HF wetlands were planted with Phragmites australis and the FWS contained a mixture of plant species. An excellent overall treatment performance was exhibited on the elimination of conventional water quality parameters (98–99% average removal efficiency for TSS, BOD5 and NH4–N; n = 8), and its final effluent proved to comply with existing Spanish regulations for various reuse applications. The removal of studied emerging Contaminants, which included various pharmaceuticals, personal care products and endocrine disruptors, was also very high (above 80% for all compounds), being compound dependent (n = 8). The high rates were achieved due to high temperatures as well as the differing existing physico-chemical conditions occurring at different CW configurations, which would allow for the combination and synergy of various abiotic/biotic removal mechanisms to occur (e.g. biodegradation, sorption, volatilization, hydrolysis, photodegradation). While aerobic metabolic pathways and solids retention are enhanced in the VF bed, other removal mechanisms such as anaerobic biodegradation and sorption would predominate in the HF bed. At last, photodegradation through direct sunlight exposure, and less importantly, sorption onto Organic matter, seem to take an active part in Organic Contaminant removal in the FWS wetland.
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Organic Contaminant loads into the western mediterranean sea estimate of ebro river inputs
Chemosphere, 2006Co-Authors: Anna Gomezgutierrez, Eric Jover, Laurent Bodineau, J Albaiges, Josep M BayonaAbstract:Annual input estimates for several Organic Contaminants from the Ebro River into the Northwestern Mediterranean Sea were carried out on the basis of monthly sampling from November 2002 to October 2003. Some organochlorine compounds (DDT and its degradation products, DDD and DDE, PCBs (9 congeners), HCB and gamma-HCH) were selected due to their reported occurrence in the river. Furthermore, some polar pesticides used in the Ebro Delta were also determined (atrazine, simazine, diazinon, fenitrothion and molinate). Concentrations ranged from 0.4 to 19.5 ng l(-1) for the organochlorine compounds (sum of particulate and dissolved phases) and from not detected (ND) to 170 ng l(-1) for the more polar pesticides, which were only found in the dissolved phase. The sum of PCB congeners (mean 8.9 ng l(-1)) showed the highest concentrations among the organochlorine compounds and atrazine (mean 82 ng l(-1)) among the polar pesticides. Based on the Contaminant concentrations and on hydrological data, Contaminant discharges into the sea were estimated amounting in total to 167 and 1,258 kg year(-1) of organochlorine compounds and polar pesticides, respectively. Furthermore, it was observed that PCBs, DDTs and HCB inputs were basically influenced by spate periods due to an increase in suspended particulate matter associated to runoff and sediment resuspension. Whereas for more water soluble Contaminants, such as the agrochemicals, their seasonal use had a higher incidence in Contaminant fluxes. Bulk chemical parameters such as SPM, DOC, POC, %OC, %ON and C/N ratio provided additional information on the Organic matter sources. This provides a better understanding of the temporal variability of the Contaminant concentrations.