scholarly journals Examination of Extracellular Polymer (EPS) Extraction Methods for Anaerobic Membrane Bioreactor (AnMBR) Biomass

2021 ◽  
Vol 13 (22) ◽  
pp. 12584
Author(s):  
Mohammed A. Galib ◽  
Timothy Abbott ◽  
Hyung-Sool Lee
Keyword(s):  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Ethylenediaminetetraacetic Acid ◽  
Complex Mixture ◽  
Oxygen Demand ◽  
Extraction Methods ◽  
Membrane Reactors ◽  
Anaerobic Microorganisms ◽  
Complex Process ◽  
Anaerobic Membrane Bioreactors

Membrane bioreactor fouling is a complex process, which is typically driven by extracellular polymeric substances (EPS), a complex mixture of polysaccharides, proteins, lipids, humic substances, and other intercellular polymers. While much is known about fouling in aerobic membrane reactors, far less is known about fouling in anaerobic membrane bioreactors (AnMBR). Much of this knowledge, including EPS extraction methods, has been extrapolated from aerobic processes and is commonly assumed to be comparable. Therefore, several extraction methods commonly used for aerobic EPS quantification, including ultrasonication, ethylenediaminetetraacetic acid (EDTA), and formaldehyde plus sodium hydroxide (CH2O+NaOH), were evaluated to determine the most suitable extraction method for EPS of anaerobic microorganisms in an AnMBR. To maximize EPS yields, each extraction was performed four times. Experimental results showed that the EDTA method was best for EPS quantification, based on chemical oxygen demand (COD), dissolved organic carbon (DOC), and protein yields: 1.43 mg COD/mg volatile suspended solids (VSS), 0.14 mg DOC/mg VSS, and 0.11 mg proteins/mg VSS. In comparison, the CH2O+NaOH method maximized the extraction of carbohydrates (0.12 mg carbohydrates/mg VSS). However, multiple extraction cycles with EDTA and ultrasonication exhibited lower extracellular adenosine triphosphate (ATP) concentrations compared to CH2O+NaOH extractions, indicating lower levels of released intracellular substances. Successive EPS extractions over four cycles are better able to quantify EPS from anaerobic microorganisms, since a single extraction may not accurately reflect the true levels of EPS contents in AnMBRs, and possibly in other anaerobic processes.

scholarly journals Treatment of Septic Tank Effluent by Membrane Bioreactor: A Laboratory–scale Feasibility Study

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
C–Y. Chang ◽  
Roger Ben Aim ◽  
S. Vigneswaran ◽  
J–S. Chang ◽  
S–L. Chen
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Laboratory Scale ◽  
Septic Tank ◽  
Term Operation ◽  
Water Cleaning ◽  
Septic Tank Effluent

A laboratory scale membrane bioreactor (MBR) fed on real septic tank effluent was studied at different levels of alkalinity (0, 250 and 500 mg NaHCO3/L addition) and sludge retention time (SRT, complete sludge retention, 10 and 20 days). A long–term operation of 267 days was divided into 5 stages to examine the SRT and alkalinity influences on parameters related to nitrification, chemical oxygen demand (COD) removal, extracellular polymeric substances (EPS) production and membrane cleaning. The results of the study showed that the removals of TCOD, SCOD and NH4+–N varied between 86–94%, 71–86%, and 70–94%, respectively. Appropriate alkalinity supplement and SRT control can enhance the COD removal and nitrification. Irreversible membrane fouling occurred fast and water cleaning for the improvement of filtration capacity was ineffective. The results also revealed that the rejection of EPS played a major role both in the enhancement of removal efficiency as well as the increase of filtration resistance during the operation.

Use of submerged anaerobic membrane bioreactor (SAMBR) containing powdered activated carbon (PAC) for the treatment of textile effluents

2012 ◽  
Vol 65 (9) ◽  
pp. 1540-1547 ◽  
Author(s):  
B. E. L. Baêta ◽  
R. L. Ramos ◽  
D. R. S. Lima ◽  
S. F. Aquino
Keyword(s):  
Activated Carbon ◽  
Membrane Bioreactor ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Excellent Performance ◽  
Reactor Stability ◽  
Anaerobic Membrane Bioreactors

This work investigated the use of submerged anaerobic membrane bioreactors (SAMBRs) in the presence and absence of powdered activated carbon (PAC) for the treatment of genuine textile wastewater. The reactors were operated at 35 °C with an HRT of 24 h and the textile effluent was diluted (1:10) with nutrient solution containing yeast extract as the source of the redox mediation riboflavin. The results showed that although both SAMBRs exhibited an excellent performance, the presence of PAC inside SAMBR-1 enhanced reactor stability and removal efficiency of chemical oxygen demand (COD), volatile fatty acids (VFA), turbidity and color. The median removal efficiencies of COD and color in SAMBR-1 were, 90 and 94% respectively; whereas for SAMBR-2 (without PAC) these values were 79 and 86%, In addition, the median values of turbidity and VFA were 8 NTU and 8 mg/L for SAMBR-1 and 14 NTU and 26 mg/L for SAMBR-2, indicating that the presence of PAC inside SAMBR-1 led to the production of an anaerobic effluent of high quality regarding such parameters.

Effective methods for extracting extracellular polymeric substances from Shewanella oneidensis MR-1

2016 ◽  
Vol 74 (12) ◽  
pp. 2987-2996 ◽  
Author(s):  
You-Fen Dai ◽  
Yong Xiao ◽  
En-Hua Zhang ◽  
Li-Dan Liu ◽  
Ling Qiu ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Ethylenediaminetetraacetic Acid ◽  
Heating Temperature ◽  
Three Dimensional ◽  
Shewanella Oneidensis ◽  
Cell Lysis ◽  
Extraction Methods ◽  
Bacterial Cells ◽  
Matrix Spectrum ◽  
Dry Cell

Extracellular polymeric substances (EPS) play crucial roles in bio-aggregate formation and survival of bacterial cells. To develop an effective but harmless method for EPS extraction from Shewanella oneidensis MR-1, five extraction methods, i.e. centrifugation (control), heating (40, 45, 50, and 60 °C), and treatments with H2SO4, ethylenediaminetetraacetic acid (EDTA) and NaOH, were examined, respectively. Results from scanning electron microscope and flow cytometric analyses indicate that MR-1 cells were severely broken by H2SO4, NaOH and heating temperature ≥45 °C. Proteins and polysaccharides in EPS extracted by heating at 40 °C were 7.12 and 1.60 mg g−1 dry cell, respectively. Although EDTA treatment had a relatively lower yield of EPS (proteins and polysaccharides yields of 5.15 and 1.30 mg g−1 dry cell, respectively), cell lysis was barely found after EPS extraction. Three peaks were identified from the three-dimensional excitation–emission matrix spectrum of each EPS sample, suggesting the presence of protein-like substances. Furthermore, the peak intensity was in good accordance with protein concentration measured by the chemical analysis. In short, heating (40 °C) and EDTA treatments were found the most suitable methods for EPS extraction considering the cell lysis and EPS content, composition and functional groups together.

scholarly journals Microbial biofouling potential of multispecies of batik dye wastewater

2018 ◽  
pp. 11-18
Keyword(s):  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Biological Membrane ◽  
Operating Time ◽  
Oxygen Demand ◽  
Bacterial Consortium ◽  
Transmembrane Pressure ◽  
Dye Wastewater ◽  
Further Development

Biofouling is a serious and challenging problem in water treatment systems which hinder the efficiency of membrane filtration performance. The aim of this study was to investigate the biofouling propensity and biological treatment performance of a bacterial consortium in a biological membrane bioreactor for the treatment of dye wastewater. During bioreactor operation with the bacterial consortium, a significant relationship was revealed between transmembrane pressure (TMP) and extracellular polymeric substances (EPS). When tested for dye and chemical oxygen demand (COD) removal, SMBR showed increased removal performance with the operating time, possibly owing to the biofilm formation on membrane and the adaptation of sludge. Thus, it is expected that the results of this study will be valuable for further development of a suitable biofouling mitigation strategy for batik wastewater treatment in membrane bioreactor. Keywords: Biofouling; biofilm, Batik wastewater; bacterial consortium; extracellular polymeric substances

scholarly journals Effects of Solids Retention Time on the Anaerobic Membrane Bioreactor with Yttria-Based Ceramic Membrane Treating Domestic Wastewater at Ambient Temperature

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 196
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Dawei Yu ◽  
Junya Zhang ◽  
Yuansong Wei
Keyword(s):  
Microbial Community ◽  
Ambient Temperature ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Archaeal Community ◽  
Stable Operation

The effects of solid retention times (SRTs) (100 days, 50 days, 25 days) on the performance, microbial community, and membrane fouling of a lab-scale anaerobic yttria-based ceramic membrane bioreactor (AnCMBR) treating synthetic domestic wastewater at ambient temperature (31.2 ± 2.7 °C) were examined. The soluble chemical oxygen demand (SCOD) removal was higher (89.6%) at 25 days SRT compared with 50 days (39.61%) and 100 days (34.3%) SRT. At 100 days SRT, more Bacteroidetes, Firmicutes, and Proteobacteria were present in the microbial community. At 25 days SRT, more Chloroflexi, Synergistetes, and Pastescibacteria emerged, contributing to the stable performance. The SRT of 25 days has resulted in a more stable microbial community compared with 50 days and 100 days SRT. Both bacterial and archaeal community diversities were higher at 25 days SRT, and the specific production of soluble microbial by-products (SMPs) and extracellular polymeric substances (EPSs) were higher at 25 days SRT as well. Consequently, the membrane flux was lower at 25 days SRT with the increased particle size and the enhanced SMPs and EPSs production. Fourier transform infrared spectroscopy analysis (FTIR) and three-dimensional excitation and emission matrix (3D-EEM) analysis showed that protein and SMPs were the major membrane foulants at all SRT stages. In this study, SRT at 25 days was favorable for the stable operation of an AnCMBR treating domestic wastewater at ambient temperature.

scholarly journals Operation of Submerged Anaerobic Membrane Bioreactors at 20 °C: Effect of Solids Retention Time on Flux, Mixed Liquor Characteristics and Performance

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1525
Author(s):  
Santiago Pacheco-Ruiz ◽  
Sonia Heaven ◽  
Charles J. Banks
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Oxygen Demand ◽  
Membrane Bioreactors ◽  
Transmembrane Pressure ◽  
Capillary Suction ◽  
Solids Retention Time ◽  
Anaerobic Membrane Bioreactors ◽  
Solids Retention

Four flat-sheet submerged anaerobic membrane bioreactors ran for 242 days on a simulated domestic wastewater with low Chemical Oxygen Demand (COD) and high suspended solids. Organic loading was maintained around 1.0 g COD L−1 day−1, while solids retention time (SRT) was varied from 20–90 days. This was achieved at a constant membrane flux, maintained by adjusting transmembrane pressure (TMP) in the range 1.8-9.8 kPa. Membrane fouling was assessed based on the required TMP, with mixed liquors characterised using capillary suction time, frozen image centrifugation and quantification of extracellular polymeric substances (EPS). SRT had a significant effect on these parameters: fouling was least at an SRT of 30 days and highest at 60 days, with some reduction as this extended to 90 days. Operation at SRT <30 days showed no further benefits. Although operation at a short SRT was optimal for membrane performance it led to lower specific methane productivity, higher biomass yields and higher effluent COD. Short SRT may also have accelerated the loss of essential trace elements, leading to reduced performance under these conditions. A COD-based mass balance was conducted, including both biomass and methane dissolved in the effluent.

Biological treatment of wastewater from fruit juice production using a membrane bioreactor: parameters limiting membrane performance

2003 ◽  
Vol 3 (5-6) ◽  
pp. 253-259
Author(s):  
C. Blöcher ◽  
T. Britz ◽  
H.D. Janke ◽  
H. Chmiel
Keyword(s):  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Fruit Juice ◽  
Operating Conditions ◽  
Production Plant ◽  
Permeate Flux ◽  
Produce Water ◽  
Membrane Performance ◽  
Test Operation

The application of a membrane bioreactor (MBR) was investigated to treat polluted process water from fruit juice processing. The aim was either direct discharge or further treatment by nanofiltration/low pressure reverse osmosis to produce water of drinking quality. The results of a one-year test operation of the process in industrial scale at a fruit juice production plant are presented. Focus was centred on the influence of activated sludge characteristics on membrane performance. Under the operating conditions in place, neither solids content, particle size distribution nor addition of nutrient significantly affected the permeate flux which was considerably lower than expected (based on municipal wastewater treatment with MBRs). Instead, evidence was obtained that the insufficient permeate flux was most likely due to the high content of extracellular polymeric substances. However, it was impossible to relate in detail the substantial flux variations during the test run to AS characteristics or changes in microbial population.

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