scholarly journals Effects of electrochemical processes application on the modification of mixed liquor characteristics of an electro-membrane bioreactor (e-MBR)

2018 ◽  
Vol 78 (11) ◽  
pp. 2364-2373 ◽  
Author(s):  
André Aguiar Battistelli ◽  
Rayra Emanuelly da Costa ◽  
Leonardo Dalri-Cecato ◽  
Tiago José Belli ◽  
Flávio Rubens Lapolli
Keyword(s):  
Electric Field ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Floc Size ◽  
Mixed Liquor ◽  
Average Value ◽  
Electrochemical Processes

Abstract This study evaluated the effects of electrochemical processes on the mixed liquor characteristics of an electro-membrane bioreactor (e-MBR) applied to municipal wastewater treatment. A laboratory-scale e-MBR was assessed under two experimental runs: without the electric field (run I) and with electric field, controlled by the application of an electric current set in 10.0 A m−2 under intermittent exposure mode of 6 minutes ON/18 minutes OFF (run II). The electric field caused approximately 55% removal of both soluble microbial products (SMP) and extracellular polymeric substances (EPS), whereas the proteins/carbohydrates ratio in EPS was increased from 1.9 in the run I to 2.9 in run II, leading to an increment of flocs' hydrophobicity. Additionally, the sludge floc size average value was reduced from 42.2 μm in run I to 24.6 μm in run II, which led to a significant enhancement in the sludge settleability. As a result, the membrane fouling rate was always less than 3.80 mbar d−1 in run II, whereas in run I these values reached up to 34.7 mbar d−1. These results demonstrated that the electrochemical processes enhanced the mixed liquor filterability. Therefore, their implementation represents a great alternative to improve the operational stability of membrane bioreactors.

Performance of membrane bioreactor combined with pre-coagulation/sedimentation

2004 ◽  
Vol 4 (1) ◽  
pp. 143-149 ◽  
Author(s):  
T. Itonaga ◽  
Y. Watanabe
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Term Operation ◽  
Made In

This paper deals with the performance of a hybrid membrane bioreactor (MBR) combined with pre-coagulation/sedimentation. Primary clarifier effluent in a municipal wastewater treatment plant was fed into the hybrid MBR to investigate its performance during long-term operation. Pre-coagulation/sedimentation process efficiently removed the suspended solids including organic matter and phosphorus. Comparison of the hybrid MBR and conventional MBR was made in terms of the permeate quality and membrane fouling. As the organic loading to the MBR was significantly reduced by the pre-coagulation/sedimentation, production and accumulation of extracellular polymeric substances (EPS) may be limited. Therefore, the mixed liquor viscosity in the hybrid MBR was much lower than that in the conventional MBR. These effect caused by pre-coagulation/sedimentation brought a remarkable improvement in both permeate quality and membrane permeability.

Identification of the effect of extracellular polymeric substances on bacterial adhesion to the membrane surface in a membrane bioreactor using Pseudomonas fluorescens

2007 ◽  
Vol 55 (1-2) ◽  
pp. 35-42 ◽  
Author(s):  
Y. Yeo ◽  
N. Jang ◽  
J. Cho ◽  
K.-S. Kim ◽  
I.S. Kim
Keyword(s):  
Pseudomonas Fluorescens ◽  
Membrane Fouling ◽  
Bacterial Adhesion ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Specific Cake Resistance

In a membrane bioreactor (MBR) process containing a variety of bacteria, the bacterial adhesion to the membrane surface, prior to cake formation, causes an increased filtration resistance. In this study, Pseudomonas fluorescens, commonly found in the municipal wastewater treatment process with activated sludge, was used to show the effects of extracellular polymeric substances (EPS) on bacterial adhesion to the membrane surface in the MBR. Of the various roles of EPS in promoting membrane fouling, the adhesion of bacteria to the membrane surface was calculated using the specific cake resistance (α, m/kg). Although the amount of EPS binding with bacteria was increased by the addition of Ca2 + , there was no significant effect on the bacterial growth. The results of the particle size distribution showed that the addition of Ca2 +  increased flocculation, allowing the formation of a complex with the bacteria and EPS. In order to identify the effects of the addition of Ca2 +  on the hydrophobicity, the contact angle was also measured. The result showed that the addition of Ca2 +  showed no significant differences in the hydrophobicity, even though there was an increase in flocculation. With the bacteria containing a higher EPS concentration, a higher specific cake resistance was observed. From the results of the adhesion experiment, which was conducted with various EPS levels, displayed as the COD and TOC concentration, an increased EPS concentration was shown to promote bacterial adhesion to the membrane surface.

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.

Comparative study on membrane fouling between membrane-coupled moving bed biofilm reactor and conventional membrane bioreactor for municipal wastewater treatment

2013 ◽  
Vol 69 (5) ◽  
pp. 1021-1027 ◽  
Author(s):  
W. Yang ◽  
W. Syed ◽  
H. Zhou
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Biofilm Reactor ◽  
Municipal Wastewater Treatment ◽  
Moving Bed Biofilm Reactor ◽  
Reactor Unit ◽  
Polyaluminum Chloride ◽  
Moving Bed

This study compared the performance between membrane-coupled moving bed biofilm reactor (M-MBBR) and a conventional membrane bioreactor (MBR) in parallel. Extensive tests were conducted in three pilot-scale experimental units over 6 months. Emphasis was placed on the factors that would affect the performance of membrane filtration. The results showed that the concentrations of soluble microbial product (SMP), colloidal total organic carbon and transparent exopolymer particles in the M-MBBR systems were not significantly different from those in the control MBR system. However, the fouling rates were much higher in the M-MBBR systems as compared to the conventional MBR systems. This indicates membrane fouling potential was related not only to the concentration of SMP, but also to their sources and characteristics. The addition of polyaluminum chloride could reduce the fouling rate of the moving bed biofilm reactor unit by 56.4–84.5% at various membrane fluxes.

A Study on a Submerged Membrane Bioreactor for Municipal Wastewater Treatment

2012 ◽  
Vol 531 ◽  
pp. 415-418 ◽  
Author(s):  
Xu Dong Liu ◽  
Ying Meng Xiu ◽  
Yan Hong Chen
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Membrane Pores ◽  
Submerged Membrane Bioreactor ◽  
Solids Concentration ◽  
Long Term Experiment

Through a long-term experiment, the performance of membrane bioreactor(MBR) for contaminants removal and membrane fouling was investigated. The results demonstrated that the removal effect of COD and NH3-N by the MBR was better. The effluent COD and NH3-N were lower than 50mg/L and 4mg/L, respectively. The observation by using the scanning electronic microscope(SEM) presented at the beginning of membrane filtration, there was no fouling in the membrane pores. With the continuous operation of the MBR, foulants shaped like mud cakes appeared in the membrane poles. The increasing of MLSS(mixed liquor suspended solids) concentration in the bioreactor didn’t increase membrane fouling. During the 75 days of operation, MBR cleaning was carried out twice.

scholarly journals Membrane Fouling Monitoring in a Submerged Membrane Bioreactor

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 653
Author(s):  
Konstantinos Azis ◽  
Marianthi Malioka ◽  
Spyridon Ntougias ◽  
Paraschos Melidis
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Cross Flow ◽  
Pilot Scale ◽  
Municipal Wastewater Treatment ◽  
Membrane Performance ◽  
Conventional Activated Sludge ◽  
Major Disadvantage

Use of Membrane Bioreactor (MBR) technology for municipal wastewater treatment has been increased in recent years, as it successfully overcomes the disadvantages of the conventional activated sludge process. Membrane fouling is the major disadvantage of MBRs and leads to decreased membrane performance and expanded operational expenses. In this study, fouling was monitored in a pilot-scale submerged MBR system fed with municipal wastewater. TMP was directly measured on the membrane module during the operation. To control TMP increase owing to biosolids accumulation on membrane surface, successive backwashes and air-cross flow velocity increase were applied. These measures lowered TMP and improved flux.

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