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How Yong Ng - One of the best experts on this subject based on the ideXlab platform.
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effects of dissolved organic matters doms on Membrane fouling in anaerobic ceramic Membrane Bioreactors ancmbrs treating domestic wastewater
Water Research, 2015Co-Authors: How Yong NgAbstract:Abstract Anaerobic Membrane Bioreactors (AnMBRs) have been regarded as a potential solution to achieve energy neutrality in the future wastewater treatment plants. Coupling ceramic Membranes into AnMBRs offers great potential as ceramic Membranes are resistant to corrosive chemicals such as cleaning reagents and harsh environmental conditions such as high temperature. In this study, ceramic Membranes with pore sizes of 80, 200 and 300 nm were individually mounted in three anaerobic ceramic Membrane Bioreactors (AnCMBRs) treating real domestic wastewater to examine the treatment efficiencies and to elucidate the effects of dissolved organic matters (DOMs) on fouling behaviours. The average overall chemical oxygen demands (COD) removal efficiencies could reach around 86–88%. Although CH4 productions were around 0.3 L/g CODutilised, about 67% of CH4 generated was dissolved in the liquid phase and lost in the permeate. When filtering mixed liquor of similar properties, smaller pore-sized Membranes fouled slower in long-term operations due to lower occurrence of pore blockages. However, total organic removal efficiencies could not explain the fouling behaviours. Liquid chromatography-organic carbon detection, fluorescence spectrophotometer and high performance liquid chromatography coupled with fluorescence and ultra-violet detectors were used to analyse the DOMs in detail. The major foulants were identified to be biopolymers that were produced in microbial activities. One of the main components of biopolymers – proteins – led to different fouling behaviours. It is postulated that the proteins could pass through porous cake layers to create pore blockages in Membranes. Hence, concentrations of the DOMs in the soluble fraction of mixed liquor (SML) could not predict Membrane fouling because different components in the DOMs might have different interactions with Membranes.
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fouling control mechanism by suspended biofilm carriers addition in submerged ceramic Membrane Bioreactors
Journal of Membrane Science, 2013Co-Authors: How Yong NgAbstract:Abstract Membrane fouling has been the main concern deterring widespread applications of Membrane Bioreactors. In this study, porous suspended biofilm carriers were introduced to submerged ceramic Membrane Bioreactors (SCMBR) treating domestic wastewater to explore its effectiveness in alleviating Membrane fouling. Results showed that biofilm carriers addition was effective in mitigating cake formation on the Membrane surface that, in turn, helped to retard Membrane fouling in SCMBR. The SCMBR without carriers had 2.7 times higher cake resistance and 1.5 times higher total resistance than the corresponding values observed in the SCMBR with carriers, indicating that the addition of biofilm carriers in SCMBR decreased the cake resistance by 72.7% over a similar period of operation. Both higher concentration of biomass and inorganic matters in the cake layer facilitated a more rapid TMP increment in the SCMBR without carriers. The liquid chromatography–organic carbon detector (LC–OCD) results indicated that a higher concentration of low molecular weight compounds (less than 1000) in the cake layer contributed to the faster fouling development observed in the SCMBR without carriers. The excitation–emission matrix florescence spectra of the cake layer showed the existence of two obvious protein-like substance peaks at the wavelength of Ex/Em=250–270/380–390 nm and Ex/Em=250–260/420–430 nm in both SCMBRs. However, relative dominance of the protein-like substance was relatively higher in the SCMBR without carriers, with an intensity of 284.9 occurring at the first peak and an intensity of 244.7 at the second peak, which confirmed that higher biopolymer contents were detected in the cake layer of the SCMBR without carriers. Other characteristics of the cake as well as the biomass suspensions were also evaluated in this study.
S J Judd - One of the best experts on this subject based on the ideXlab platform.
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Membrane Bioreactors for wastewater treatment
Water intelligence online, 2015Co-Authors: Tom Stephenson, S J Judd, Keith Brindle, Bruce JeffersonAbstract:The book covers the subject of Membrane Bioreactors (MBR) for wastewater treatment, dealing with municipal as well as industrial wastewaters. The book details the 3 types of MBR available and discusses the science behind the technology, their design features, operation, applications, advantages, limitations, performance, current research activities and cost. As the demand for wastewater treatment, recycling and re-use technologies increases, it is envisaged that the Membrane separation bioreactor will corner the market. This title belongs to WERF Research Report Series ISBN: 9781900222075 (Print) ISBN: 9781780402147 (eBook)
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impact of Membrane configuration on fouling in anaerobic Membrane Bioreactors
Journal of Membrane Science, 2011Co-Authors: I Martingarcia, S J Judd, Marc Pidou, V M Monsalvo, Pierre Leclech, Ewan J Mcadam, Bruce JeffersonAbstract:Abstract The filtration performance of flocculated and granulated configured anaerobic Membrane Bioreactors (MBR) treating domestic wastewater has been evaluated and compared to conventional aerobic MBR. Immersed hollow fibre (HF) and external tubular Membrane geometries were additionally compared with the latter operated in both pumped and gas-lift mode. After 200 d of operation, both granular and flocculated anaerobic MBR (AnMBR) suspensions were characterised by an increased population of colloidal particles while the aerobic MBR retained a unimodal particle size distribution with a d 50 of 20 μm. Consequently, the flocculated AnMBR supernatant was characterised by a soluble microbial product (SMP) concentration ca. 500% higher than the aerobic MBR, such that the lowest critical fluxes for both HF and tubular Membranes were recorded for the AnMBR. In comparison, the granulated AnMBR sludge was characterised by a low mixed liquor suspended solids concentration and an SMP concentration below 50% that of the flocculated anaerobic MBR. Consequently, similar fluxes to those of the aerobic MBR were achieved with the granulated anaerobic sludge using immersed HF Membranes. Operating external tubular Membranes in gas-lift appeared less effective for the granular AnMBR than the Aerobic MBR. However, critical fluxes >40 L m −2 h −1 were achieved using pumped mode. Results suggest granular AnMBR systems to be most suited to domestic wastewater treatment using either immersed HF Membranes or external tubular Membranes in pumped crossflow mode.
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modelling the energy demands of aerobic and anaerobic Membrane Bioreactors for wastewater treatment
Environmental Technology, 2011Co-Authors: I Martin, S J Judd, Marc Pidou, Ana Soares, Bruce JeffersonAbstract:A modelling study has been developed in which the energy requirements of aerobic and anaerobic Membrane Bioreactors (MBRs) are assessed in order to compare these two wastewater treatment technologies. The model took into consideration the aeration required for biological oxidation in aerobic MBRs (AeMBRs), the energy recovery from methane production in anaerobic MBRs (AnMBRs) and the energy demands of operating submerged and sidestream Membrane configurations. Aeration and Membrane energy demands were estimated based on previously developed modelling studies populated with operational data from the literature. Given the difference in sludge production between aerobic and anaerobic systems, the model was benchmarked by assuming high sludge retention times or complete retention of solids in both AeMBRs and AnMBRs. Analysis of biogas production in AnMBRs revealed that the heat required to achieve mesophilic temperatures (35°C) in the reactor was only possible with influent wastewater strengths above 4–5 g CO...
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biomass effects on oxygen transfer in Membrane Bioreactors
Water Research, 2007Co-Authors: E Germain, F Nelles, Pete Pearce, E Reid, S J Judd, Matthias Kraume, Anja Drews, Tom StephensonAbstract:Fine bubble aeration and biomass characteristics were studied for their impact on oxygen transfer in Membrane Bioreactors (MBRs). Ten biomass samples from both municipal and industrial pilot and full scale submerged MBRs with mixed liquor suspended solids concentrations (MLSS) ranging from 7.2 to 30.2 g.L -1 were studied at six air flow rates (0.7, 1.3, 2.3, 3, 4.4 and 6 m 3 .m -3 .h -1 ). Graphical and statistical analyses were applied to the results to identify the relative impacts of the various bulk biomass characteristics on oxygen transfer, the former being solids concentration,
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the mbr book principles and applications of Membrane Bioreactors for water and wastewater treatment
2006Co-Authors: S J JuddAbstract:A Membrane BioReactor (MBR) is the combination of a Membrane process (e.g. microfiltration/ ultrafiltration) with a suspended growth bioreactor. When used with domestic wastewater, MBR processes can produce effluent of high enough quality to be discharged to waterways, or to be reclaimed for urban irrigation. Other advantages of MBRs over conventional processes include small footprint, easy retrofit and upgrade of old wastewater treatment plants. The MBR Book covers all important aspects of Membrane Bioreactors in water and waste water treatment, from the fundamentals of the processes via design principles to MBR technologies. Industrial case studies help interpret actual results and give pointers for best practice. Useful appendices provide data on commercial Membranes and international Membrane organizations. The MBR book enables readers to: Understand the fundamental processes involved in Membrane and biotreatment technologies Compare and contrast design options and work through sample calculations Review commercial MBR systems in terms of specific applications Learn from case studies involving domestic and industrial effluent treatment and recycling Analyze process design, operation, performance and maintenance to draw conclusions appropriate to their requirements New to the second edition: 45% more content than the first edition. Over 120 contributors from the academic research and municipal/industrial practitioner communities. Review of MBR status in ten countries. Expanded section on anaerobic MBRs, micropollutant fate and hybrid systems. Simplified design methodology, with biokinetics for dynamic modelling and cost benefit analysis. Expanded operation and maintenance section, informed by expert panel of practitioners offering more than 40 years combined experience. Over 40 MBR Membrane products described, with most of the technical specifications provided. Over 50 case studies provided, including key design, performance, and operation and maintenance data in almost all cases. Membrane Bioreactors are a major growth area in the water and waste water treatment industries Internationally-known author, one of the leading senior experts in MBR research Principles and practice, backed by industrial case studies
Bruce Jefferson - One of the best experts on this subject based on the ideXlab platform.
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Membrane Bioreactors for wastewater treatment
Water intelligence online, 2015Co-Authors: Tom Stephenson, S J Judd, Keith Brindle, Bruce JeffersonAbstract:The book covers the subject of Membrane Bioreactors (MBR) for wastewater treatment, dealing with municipal as well as industrial wastewaters. The book details the 3 types of MBR available and discusses the science behind the technology, their design features, operation, applications, advantages, limitations, performance, current research activities and cost. As the demand for wastewater treatment, recycling and re-use technologies increases, it is envisaged that the Membrane separation bioreactor will corner the market. This title belongs to WERF Research Report Series ISBN: 9781900222075 (Print) ISBN: 9781780402147 (eBook)
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impact of Membrane configuration on fouling in anaerobic Membrane Bioreactors
Journal of Membrane Science, 2011Co-Authors: I Martingarcia, S J Judd, Marc Pidou, V M Monsalvo, Pierre Leclech, Ewan J Mcadam, Bruce JeffersonAbstract:Abstract The filtration performance of flocculated and granulated configured anaerobic Membrane Bioreactors (MBR) treating domestic wastewater has been evaluated and compared to conventional aerobic MBR. Immersed hollow fibre (HF) and external tubular Membrane geometries were additionally compared with the latter operated in both pumped and gas-lift mode. After 200 d of operation, both granular and flocculated anaerobic MBR (AnMBR) suspensions were characterised by an increased population of colloidal particles while the aerobic MBR retained a unimodal particle size distribution with a d 50 of 20 μm. Consequently, the flocculated AnMBR supernatant was characterised by a soluble microbial product (SMP) concentration ca. 500% higher than the aerobic MBR, such that the lowest critical fluxes for both HF and tubular Membranes were recorded for the AnMBR. In comparison, the granulated AnMBR sludge was characterised by a low mixed liquor suspended solids concentration and an SMP concentration below 50% that of the flocculated anaerobic MBR. Consequently, similar fluxes to those of the aerobic MBR were achieved with the granulated anaerobic sludge using immersed HF Membranes. Operating external tubular Membranes in gas-lift appeared less effective for the granular AnMBR than the Aerobic MBR. However, critical fluxes >40 L m −2 h −1 were achieved using pumped mode. Results suggest granular AnMBR systems to be most suited to domestic wastewater treatment using either immersed HF Membranes or external tubular Membranes in pumped crossflow mode.
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modelling the energy demands of aerobic and anaerobic Membrane Bioreactors for wastewater treatment
Environmental Technology, 2011Co-Authors: I Martin, S J Judd, Marc Pidou, Ana Soares, Bruce JeffersonAbstract:A modelling study has been developed in which the energy requirements of aerobic and anaerobic Membrane Bioreactors (MBRs) are assessed in order to compare these two wastewater treatment technologies. The model took into consideration the aeration required for biological oxidation in aerobic MBRs (AeMBRs), the energy recovery from methane production in anaerobic MBRs (AnMBRs) and the energy demands of operating submerged and sidestream Membrane configurations. Aeration and Membrane energy demands were estimated based on previously developed modelling studies populated with operational data from the literature. Given the difference in sludge production between aerobic and anaerobic systems, the model was benchmarked by assuming high sludge retention times or complete retention of solids in both AeMBRs and AnMBRs. Analysis of biogas production in AnMBRs revealed that the heat required to achieve mesophilic temperatures (35°C) in the reactor was only possible with influent wastewater strengths above 4–5 g CO...
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sub critical flux fouling in Membrane Bioreactors a review of recent literature
Desalination, 2005Co-Authors: Alfieri Pollice, Bruce Jefferson, A Brookes, S J JuddAbstract:Abstract Membrane fouling is one of the main factors affecting the diffusion of Membrane Bioreactors to wastewater treatments. Fouling is generally held to persist above a so-called “critical flux”, below which a steady-state Membrane permeability is assumed to be attainable. However, a number of recent studies have demonstrated that low-level fouling can take place at very low fluxes which are substantially below the critical value. This short survey is focused on reported evidences of Membrane fouling under sub-critical conditions and examines possible links between operational paramenters, mixed liquor characteristics and fouling propensity. The reported experimental evidences suggest no unequivocal connection between parameters such as permeability decline (dK/dt) and fouling rate (dP/dt) and sustainable long term sub-critical operation. In this respect, test size and plant configuration also play a relevant role. Step-flux experiments may provide information on fouling propensity under sub-critical flux, but the fouling rates determined with this method are generally not applicable to long term operation. Mixed liquor quality determinants such as EPS and SMP and their relative protein/carbohydrate ratios are likely to contribute to sub-critical fouling in MBRs. Possible relationships between these parameters and plant operation (sludge age, biomass concentration, hydraulic retention time, etc.) are briefly discussed.
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Membrane fouling in Membrane Bioreactors for wastewater treatment
Journal of Environmental Engineering, 2002Co-Authors: Insoung Chang, Bruce Jefferson, Pierre Le Clech, S J JuddAbstract:Membrane Bioreactors (MBRs), in which Membranes are applied to biological wastewater treatment for biomass separation, provide many advantages over conventional treatment. However, Membrane fouling in MBRs restricts their widespread application because it reduces productivity and increases maintenance and operating costs. Recently much research and development has taken place to investigate, model, and control Membrane fouling processes. However, unified and well-structured theories on Membrane fouling are not currently available because of the complexity of the biomass matrix, which is highly heterogeneous and includes living microorganisms. Membrane fouling in MBR systems can be reversible (i.e., removable by physical washing) or irreversible (removable by chemical cleaning only), and can take place on the Membrane surface or into the Membrane pores. Although establishing a general model to describe Membrane fouling in such a process is made extremely difficult by the inherent heterogeneity of the syste...
Y Watanabe - One of the best experts on this subject based on the ideXlab platform.
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elimination of selected acidic pharmaceuticals from municipal wastewater by an activated sludge system and Membrane Bioreactors
Environmental Science & Technology, 2007Co-Authors: Katsuki Kimura, Hiroe Hara, Y WatanabeAbstract:The elimination of six acidic pharmaceuticals (clofibric acid, diclofenac, ibuprofen, ketoprofen, mefenamic acid, and naproxen) in a real wastewater treatment plant (WWTP) using an activated sludge system and Membrane Bioreactors (MBRs) was investigated by using a gas chromatography/mass spectrometry (GC/MS) system for measurement of the compounds. Limited information is available for some of the tested pharmaceuticals at present. Solid retention times (SRTs) of the WWTP and the two MBRs were 7, 15, and 65 days, respectively. The elimination rates varied from compound to compound. The MBRs exhibited greater elimination rates for the examined pharmaceuticals than did the real plant. Dependency of the elimination rates of the pharmaceuticals on SRTs was obvious; the MBR operated with a longer SRT of 65 days clearly showed better performance than did the MBR with a shorter SRT of 15 days. The difference between the two MBRs was particularly significant in terms of elimination of ketoprofen and diclofenac. Me...
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Membrane biofouling in pilot scale Membrane Bioreactors mbrs treating municipal wastewater impact of biofilm formation
Environmental Science & Technology, 2007Co-Authors: Yuki Miura, Y Watanabe, Satoshi OkabeAbstract:For more efficient control and prediction of Membrane biofouling in Membrane Bioreactors (MBRs), a fundamental understanding of mechanisms of Membrane biofouling is essential. In this study, we operated full-scale submerged MBRs using real municipal wastewater delivered from the primary sedimentation basin of a municipal wastewater treatment facility over 3 months, and the adhesion and formation of biofilms on 0.4-μm pore size polyethylene hollow-fiber microfiltration (MF) Membrane surfaces, separated from simple deposition of sludge cake, were monitored using scanning electron microscopy (SEM). In addition, the compositions of planktonic and biofilm microbial communities in the MBR were analyzed using culture independent molecular-based methods (i.e., fluorescent in situ hybridization (FISH) and 16S rRNA gene sequence analysis). The SEM and LIVE/DEAD staining analyses clearly showed that the biofilms gradually developed on the Membrane surfaces with time, which had a strong positive correlation with the ...
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Difference in Membrane fouling in Membrane Bioreactors (MBRs) caused by Membrane polymer materials
Journal of Membrane Science, 2006Co-Authors: Nobuhiro Yamato, Katsuki Kimura, Taro Miyoshi, Y WatanabeAbstract:There is a need for efficient control of Membrane fouling in Membrane Bioreactors (MBRs), but there is still an insufficient understanding of the phenomena of Membrane fouling and little is known about the influence of polymeric Membrane materials on Membrane fouling in MBRs. In this study, the influence of polymeric Membrane materials on Membrane fouling in MBRs was investigated on the basis of results of a pilot-scale experiment using real municipal wastewater. Two different polymers, polyethylene (PE) and polyvinylidene fluoride (PVDF), were examined side by side and the degree of fouling in each Membrane was monitored. Also, analysis of the foulants in both Membranes was carried out. The results obtained in this study demonstrated that PVDF is superior to PE in terms of prevention of irreversible fouling in MBRs used for treatment of municipal wastewater. Dissolved matter was mainly responsible for the irreversible fouling. Reversible fouling in the PVDF Membrane might be related to an increase in sub-micron-sized organic matter that was mainly composed of carbohydrate. Composition of the foulants causing irreversible fouling differed considerably depending on the Membrane polymeric materials. The results suggested that some fractions in organic matter in the mixed liquor have higher affinities with the Membrane than do other fractions and consequently cause greater irreversible fouling.
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Membrane fouling in pilot scale Membrane Bioreactors mbrs treating municipal wastewater
Environmental Science & Technology, 2005Co-Authors: Katsuki Kimura, Nobuhiro Yamato, Hiroshi Yamamura, Y WatanabeAbstract:The main obstacle for wider use of Membrane Bioreactors (MBRs) for wastewater treatment is Membrane fouling (i.e., deterioration of Membrane permeability), which increases operating costs. For more efficient control of Membrane fouling in MBRs, an understanding of the mechanisms of Membrane fouling is important. However, there is a lack of information on Membrane fouling in MBRs, especially information on features of components that are responsible for the fouling. We conducted a pilot-scale experiment using real municipal wastewater with three identical MBRs under different operating conditions. The results obtained in this study suggested that the food−microorganisms ratio (F/M) and Membrane filtration flux were the important operating parameters that significantly influenced Membrane fouling in MBRs. Neither concentrations of dissolved organic matter in the reactors nor viscosity of mixed liquor, which have been thought to have influences on fouling in MBRs, showed clear relationships with Membrane fou...
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removal of pharmaceutical compounds by submerged Membrane Bioreactors mbrs
Desalination, 2005Co-Authors: Katsuki Kimura, Hiroe Hara, Y WatanabeAbstract:Unintentional indirect potable water reuse, where wastewater effluent is used as a part of a downstream drinking water source, has become a great concern. In this case, a variety of organic micro-pollutants contained in wastewater effluent could create problems. Membrane Bioreactors (MBRs) have gained significant popularity as an advanced wastewater treatment technology and might be effective in removing such organic micro-pollutants. Available information on the performance of MBRs regarding removal of micro-pollutants, however, is currently limited. This study examined the ability of submerged MBRs to remove pharmaceutically active compounds (PhACs). Experiments were conducted at an existing municipal wastewater treatment facility, and the performance of the MBRs was compared with that of the conventional activated sludge (CAS) process. Six acidic PhACs (clofibric acid, diclofenac, ibuprofen, ketoprofen, mefenamic acid, naproxen) and one acidic herbicide (dichloprop) were investigated. Compared with CAS, MBRs exhibited much better removal regarding ketoprofen and naproxen. With respect to the other compounds, comparable removal was observed between the two types of treatment. Removal efficiencies of the PhACs were found to be dependent on their molecular structure such as number of aromatic rings or inclusion of chlorine.
Fangang Meng - One of the best experts on this subject based on the ideXlab platform.
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Fouling in Membrane Bioreactors: An updated review
Water Research, 2017Co-Authors: Fangang Meng, Yoontaek Oh, Shaoqing Zhang, Zhongbo Zhou, Hang-sik Shin, So Ryong ChaeAbstract:The goal of the current article is to update new findings in Membrane fouling and emerging fouling mitigation strategies reported in recent years (post 2010) as a follow-up to our previous review published in Water Research (2009). According to a systematic review of the literature, Membrane Bioreactors (MBRs) are still actively investigated in the field of wastewater treatment. Notably, Membrane fouling remains the most challenging issue in MBR operation and attracts considerable attention in MBR studies. In this review, we summarized the updated information on foulants composition and characteristics in MBRs, which greatly improves our understanding of fouling mechanisms. Furthermore, the emerging fouling control strategies (e.g., mechanically assisted aeration scouring, in-situ chemical cleaning, enzymatic and bacterial degradation of foulants, electrically assisted fouling mitigation, and nanomaterial-based Membranes) are comprehensively reviewed. As a result, it is found that the fundamental understanding of dynamic changes in Membrane foulants during a long-term operation is essential for the development and implementation of fouling control methods. Recently developed strategies for Membrane fouling control denoted that the improvement of Membrane performance is not our ultimate and only goal, less energy consumption and more green/sustainable fouling control ways are more promising to be developed and thus applied in the future. Overall, such a literature review not only demonstrates current challenges and research needs for scientists working in the area of MBR technologies, but also can provide more useful recommendations for industrial communities based on the related application cases.
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Recent Advances in Membrane Bioreactors: Configuration Development, Pollutant Elimination, and Sludge Reduction
Environmental Engineering Science, 2012Co-Authors: Fangang Meng, So Ryong Chae, Fenglin Yang, Hang-sik Shin, Zhongbo ZhouAbstract:Abstract Membrane Bioreactors (MBRs) are composed of activated sludge processes and Membrane filtration. Because of their unique advantages such as good effluent quality and compact structure, MBRs have been widely used for municipal and industrial wastewater treatment. Recent advances in MBR research are reviewed by focusing on development of bioreactor configurations, enhanced degradation of pollutants, and sludge reduction. Efforts of a number of novel MBR processes such as hybrid biofilm MBR, submerged rotating MBR, MBR with reverse osmosis, osmotic MBR, Membrane distillation bioreactor, air-sparging MBR, and jet loop MBR for the treatment of nitrogen, phosphorous, emerging contaminants, heavy metals, and sludge reduction are summarized. Process principles, benefits, and limitations of these MBRs are discussed. According to a detailed analysis of research publications, MBR research has undergone an extensive growth in the areas of development of novel MBR configurations and application of MBRs with ne...
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morphological visualization componential characterization and microbiological identification of Membrane fouling in Membrane Bioreactors mbrs
Journal of Membrane Science, 2010Co-Authors: Fangang Meng, Fenglin Yang, Bao-qiang Liao, Shuang Liang, Hanmin Zhang, Lianfa SongAbstract:So far, Membrane fouling in Membrane Bioreactors (MBRs) is still not fully understood due to the complex nature of Membrane foulants. The challenge to the study of Membrane fouling behavior and Membrane fouling mechanisms calls for the use and/or development of novel approaches for clearer understanding of Membrane foulants such as structure and configuration of fouling layer, physicochemical and biological nature of Membrane foulants, and deposition behavior of microorganisms on Membranes. As such, MBR fouling can be characterized by the following: (i) visualization of cake morphology, (ii) analysis of chemical composition and, (iii) identification of microbial community structure. The state-of-the-art approaches used for Membrane fouling study are critically reviewed in this paper. The advantages and limitations of currently used approaches are discussed as well. Lastly, potential approaches that can be applied for the characterization of Membrane fouling in MBRs in the future are mentioned.
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recent advances in Membrane Bioreactors mbrs Membrane fouling and Membrane material
Water Research, 2009Co-Authors: So Ryong Chae, Fangang Meng, Hang-sik Shin, Matthias Kraume, Anja Drews, Fenglin YangAbstract:Membrane Bioreactors (MBRs) have been actively employed for municipal and industrial wastewater treatments. So far, Membrane fouling and the high cost of Membranes are main obstacles for wider application of MBRs. Over the past few years, considerable investigations have been performed to understand MBR fouling in detail and to develop high-flux or low-cost Membranes. This review attempted to address the recent and current developments in MBRs on the basis of reported literature in order to provide more detailed information about MBRs. In this paper, the fouling behaviour, fouling factors and fouling control strategies were discussed. Recent developments in Membrane materials including low-cost filters, Membrane modification and dynamic Membranes were also reviewed. Lastly, the future trends in Membrane fouling research and Membrane material development in the coming years were addressed.
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effect of hydraulic retention time on Membrane fouling and biomass characteristics in submerged Membrane Bioreactors
Bioprocess and Biosystems Engineering, 2007Co-Authors: Fangang Meng, Fenglin Yang, Baoqiang Shi, Hanmin ZhangAbstract:In this paper, three identical Membrane Bioreactors (MBRs) were operated in parallel in order to specify the influence mechanism of hydraulic retention time (HRT) on MBR. The results showed that the removal efficiency of chemical oxygen demand (COD) was stable though it decreased slightly as HRT decreased, but biomass activity and dissolved oxygen (DO) concentration in sludge suspension decreased as HRT decreased. The filamentous bacteria grew easily with decreasing HRT. The extracellular polymeric substances (EPS) concentration and sludge viscosity increased significantly as filamentous bacteria excessively grew. The over growth of filamentous bacteria, the increase of EPS and the decrease of shear stress led to the formation of large and irregular flocs. Furthermore, the mixed liquid suspended solids (MLSS) concentration and sludge viscosity increased significantly as HRT decreased. The results also indicated that sludge viscosity was the predominant factor that affecting hydrodynamic conditions of MBR systems.
