Membrane Fouling in Pilot-Scale Membrane Bioreactors (MBRs) Treating Municipal Wastewater

2005 ◽  
Vol 39 (16) ◽  
pp. 6293-6299 ◽  
Author(s):  
Katsuki Kimura ◽  
Nobuhiro Yamato ◽  
Hiroshi Yamamura ◽  
Yoshimasa Watanabe
Keyword(s):  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Membrane Bioreactors

Membrane fouling caused by sub-micron particles in a mixed liquor suspension of an MBR

2013 ◽  
Vol 67 (11) ◽  
pp. 2602-2607 ◽  
Author(s):  
K. Kimura ◽  
R. Ogyu ◽  
T. Miyoshi ◽  
T. Naruse ◽  
T. Tsuyuhara ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Size Fraction ◽  
Fourier Transform Infrared ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Ftir Analysis ◽  
Mixed Liquor ◽  
Pore Plugging

Membrane fouling needs to be mitigated for widespread use of membrane bioreactors (MBRs). It has been pointed out that particles with small sizes found in supernatants (sub-micron particles) of mixed liquor suspensions of MBRs are important in the evolution of membrane fouling of this technology. However, information on characteristics of sub-micron particles in MBRs is still insufficient. In this study, a pilot-scale MBR treating municipal wastewater was used to investigate and characterize sub-micron particles in an MBR and to identify the size fraction(s) responsible for irreversible fouling in an MBR. It was clearly shown that characteristics of sub-micron particles in the MBR varied considerably depending on their sizes. Results of Fourier transform infrared (FTIR) analysis and monosaccharide analysis suggested that irreversible fouling in this study was mainly caused by the specific size fraction of 0.1–0.45 μm, which was close to the size of micropores of the membrane used. Pore plugging might explain this to some extent.

Proteins causing membrane fouling in membrane bioreactors

2015 ◽  
Vol 72 (6) ◽  
pp. 844-849 ◽  
Author(s):  
Taro Miyoshi ◽  
Yuhei Nagai ◽  
Tomoyasu Aizawa ◽  
Katsuki Kimura ◽  
Yoshimasa Watanabe
Keyword(s):  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Polyacrylamide Gel Electrophoresis ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Sequencing Analysis ◽  
2D Page ◽  
Side Stream ◽  
Significant Difference

In this study, the details of proteins causing membrane fouling in membrane bioreactors (MBRs) treating real municipal wastewater were investigated. Two separate pilot-scale MBRs were continuously operated under significantly different operating conditions; one MBR was a submerged type whereas the other was a side-stream type. The submerged and side-stream MBRs were operated for 20 and 10 days, respectively. At the end of continuous operation, the foulants were extracted from the fouled membranes. The proteins contained in the extracted foulants were enriched by using the combination of crude concentration with an ultrafiltration membrane and trichloroacetic acid precipitation, and then separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The N-terminal amino acid sequencing analysis of the proteins which formed intensive spots on the 2D-PAGE gels allowed us to partially identify one protein (OmpA family protein originated from genus Brevundimonas or Riemerella anatipestifer) from the foulant obtained from the submerged MBR, and two proteins (OprD and OprF originated from genus Pseudomonas) from that obtained from the side-stream MBR. Despite the significant difference in operating conditions of the two MBRs, all proteins identified in this study belong to β-barrel protein. These findings strongly suggest the importance of β-barrel proteins in developing membrane fouling in MBRs.

Correlation between membrane fouling and soluble/colloidal organic substances in membrane bioreactors for municipal wastewater treatment

2005 ◽  
Vol 51 (6-7) ◽  
pp. 1-8 ◽  
Author(s):  
B. Lesjean ◽  
S. Rosenberger ◽  
C. Laabs ◽  
M. Jekel ◽  
R. Gnirss ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Size Exclusion ◽  
Water Phase ◽  
Parallel Operation ◽  
Municipal Wastewater Treatment ◽  
Operational Conditions ◽  
The Difference

Two similar membrane bioreactors of 2 m3 each were operated in parallel over two years under the same operational conditions, fed with the same municipal wastewater. The only process and operational difference between both pilot plants was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite parallel operation, the two MBRs exhibited different fouling rates and decreases in permeability. These differences could not be accounted for by MLSS concentrations, loading rates, or filtration flux. In a one-year investigation, soluble and colloidal organic material in the activated sludge of both MBR was regularly analysed by spectrophotometric and Size Exclusion Chromatography (SEC) methods. The larger organic molecules present in the sludge water phase (i.e. polysaccharides, proteins and organic colloids) originating from microbial activity (extracellular polymeric substances) were found to impact on the fouling and to explain the difference in membrane performance between the two MBR units. In both pilot plants, a linear relationship could be clearly demonstrated between the fouling rate of the membrane and the concentration of polysaccharides in the sludge water phase during a 5 month operational period at an SRT of 8 days.

scholarly journals Long-Term Investigation into the Membrane Fouling Behavior in Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment Operated at Two Different Temperatures

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 231
Author(s):  
Yi Ding ◽  
Zhansheng Guo ◽  
Zhenlin Liang ◽  
Xuguang Hou ◽  
Zhipeng Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Municipal Wastewater Treatment ◽  
Sludge Flocs ◽  
Microbial Product ◽  
Anaerobic Membrane Bioreactors ◽  
Sludge Particle

In this study, the characteristics of activated sludge flocs were investigated and their effects on the evolution of membrane fouling were considered in the anaerobic membrane bioreactors (AnMBR), which were operated at 25 and 35 °C for municipal wastewater treatment. It was found that the membrane fouling rate of the AnMBR at 25 °C was more severe than that at 35 °C. The membrane fouling trends were not consistent with the change in the concentration of soluble microbial product (SMP). The larger amount of SMP in the AnMBR at 35 °C did not induce more severe membrane fouling than that in the AnMBR at 25 °C. However, the polysaccharide and protein concentration of extracellular polymeric substance (EPS) was higher in the AnMBR at 25 °C in comparison with that in the AnMBR at 35 °C, and the protein/polysaccharide ratio of the EPS in the AnMBR at 25 °C was higher in contrast to that in the AnMBR at 35 °C. Meanwhile, the fouling tendencies measured for the AnMBRs could be related to the characteristics of loosely bound EPS and tightly bound EPS. The analysis of the activated sludge flocs characteristics indicated that a smaller sludge particle size and more fine flocs were observed at the AnMBR with 25 °C. Therefore, the membrane fouling potential in the AnMBR could be explained by the characteristics of activated sludge flocs.

scholarly journals Microcoagulation improved the performance of the UF–RO system treating the effluent from a coastal municipal wastewater treatment plant: a pilot-scale study

2021 ◽  
Author(s):  
Tong Yu ◽  
Chenlu Xu ◽  
Feng Chen ◽  
Haoshuai Yin ◽  
Hao Sun ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Contaminant Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plant ◽  
Ro Membrane

Abstract Microcoagulation has recently been considered as a promising pretreatment for an ultrafiltration (UF) process from numerous studies. To investigate the effects of microcoagulation on the performance of the UF–reverse osmosis (RO) system treating wastewater with high and fluctuant salinity, different dosages of coagulant (poly-aluminum chloride) were added prior to the UF unit in a pilot-scale UF–RO system for a 10-week period operation. Microcoagulation obviously improved the contaminant removal and cleaning efficiencies, including water backwash, chemical enhanced backwash and cleaning in place processes. Organic fouling was dominated during the initial stage of the RO membrane fouling. The microbial communities of water samples and foulant on the RO membrane were similar to those of seawater and foulant on the RO membranes from seawater RO plants. The microbial community of the foulant on the membrane was similar to that of UF permeate and RO concentrate. These results demonstrated that microcoagulation could improve the performance of the UF–RO system treating the effluent with high and fluctuant salinity from a coastal municipal wastewater treatment plant.

scholarly journals Characterization of microbial aggregates in relation to membrane biofouling in submerged membrane bioreactors

2021 ◽  
Author(s):  
Heather Elizabeth Kraemer
Keyword(s):  
Laser Scanning ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Laser Scanning Microscopy ◽  
The Other ◽  
Major Constituent ◽  
Confocal Laser ◽  
Microbial Flocs

The purpose of this study was to characterize microbial aggregates and extracellular polymeric substances (EPS) that contribute to biofouling of submerged polymeric microfiltration membranes. Two issues were addressed in this study, (1) the influence operational and recovery cleanings of membranes have on biofouling amelioration and (2) the influence physicochemical properties of microbial flocs have on biofouling. The experiments in this study employed two pilot scale Zee Weed™ membrane bioreactors (MBRs). In one MBR, a ZW-I0 module was installed to treat secondary municipal wastewater at a sludge retention time (SRT) of30 days and operated under permeate/relaxation conditions. In the other MBR, two ZW -10 modules were installed to treat secondary municipal wastewater at an SRT of 12 days. One module operated under permeate/relaxation conditions, while the other operated under permeate/backwash conditions. Sludge samples from the MBRs were characterized by measuring the surface charge, hydrophobicity, and EPS composition of the microbial flocs. Membrane fibre samples were collected from each ZW -10 module during permeation and after recovery cleanings. The biofoulant on the membrane was analyzed using confocal laser scanning microscopy (CLSM) after simultaneous staining with the lectins concanavalin A (ConA), wheat germ agglutinin (WGA), and soybean agglutinin (SBA). The CLSM analysis of the membrane fibres sampled showed that the biofoulant on the membrane was composed of a heterogeneous colonization of microbes and EPS known to contain glucose, mannose, N -acetylglucosamine, and galactose. The dominant carbohydrate in the biofoulant was shown to be N -acetylglucosamine, which is part of both the cell wall of bacteria and the extracellular matrix. The reversible biofoulant was composed of individual cells, aggregates of cells, and EPS. The major constituent of the irreversible biofoulant was inferred to be EPS, which was observed as a fibrous network of material that remained adhered to the membrane after recovery cleaning the modules with a 2000 ppm hypochlorite solution. By using a permeate backwash rather than relaxation as an operational cleaning method, the rate of biofouling may be reduced. The rate of biofoulant accumulation on hydrophilic membranes may be reduced at higher SR Ts because the biomass at higher SR Ts has a higher hydrophobicity when compared to the biomass at lower SRTs.

Water reclamation with membrane bioreactors

2001 ◽  
Vol 1 (5-6) ◽  
pp. 293-302 ◽  
Author(s):  
P. Gagliardo ◽  
S. Adham ◽  
R.P. Merlo ◽  
R.S. Trussell ◽  
R.R. Trussell
Keyword(s):  
Thin Film ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Water Reclamation ◽  
Film Composite ◽  
Bureau Of Reclamation ◽  
Thin Film Composite ◽  
Feed Source ◽  
The City

The City of San Diego was awarded a grant from the Bureau of Reclamation to investigate the feasibility of using Membrane Bioreactors (MBRs) for water reclamation. Based on the findings of the first phase of the project (Adham et al., 1998), the project team concluded that a parallel comparison of commercially available MBR systems needed to be evaluated at pilot-scale. Two submerged MBR systems were evaluated at the Aqua 2000 Research Center in Escondido, California. The project was designed to evaluate the MBR performance treating municipal wastewater and the feasibility of using the MBR permeate as a feed source for thin film composite reverse osmosis (RO) membranes. The first part of the project was dedicated to operating both MBRs in a nitrification and denitrification mode. After completion of Part 1 of the project, both MBR systems were retrofitted and operated in a nitrification only mode. Throughout both parts of the study, the effluent from each MBR was fed to two separate, single stage RO pilot systems. Both MBR systems showed high BOD removal with values below the detection limit, and significant TOC reduction. The effluent turbidities from the MBRs were consistently less than 0.1 NTU. Both MBRs also produced a high quality effluent that could be used by thin film composite RO membranes with minimal fouling.

Modification of submerged membrane bioreactors (MBRs) by inserting baffles: pilot scale study

2007 ◽  
Vol 55 (7) ◽  
pp. 119-126 ◽  
Author(s):  
K. Kimura ◽  
M. Enomoto ◽  
Y. Watanabe
Keyword(s):  
Phosphorus Removal ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Feed Water ◽  
Simple Modification ◽  
Anoxic Conditions ◽  
Scale Experiment

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is difficulty in removing nitrogen as they are accompanied with intensive aeration inside the reactor and therefore principally operated under aerobic conditions. In order to address this problem, a simple modification for submerged MBRs, insertion of baffles to create alternative aerobic/anoxic conditions, was proposed. In this study, the performance of the proposed baffled membrane bioreactor (BMBR) was investigated based on a pilot-scale experiment using a real municipal wastewater. With appropriate operating conditions, the BMBR could remove more than 70% of total nitrogen contained in the feed water without any external carbon source. The BMBR demonstrated a good treatment performance in terms of TOC and phosphorus removal as well. Increase of trans-membrane pressure difference was subtle, which might be attributed to the alternative creation of aerobic/anoxic conditions.

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