Effect of a suspended carrier on membrane fouling in a submerged membrane bioreactor

2006 ◽  
Vol 53 (6) ◽  
pp. 211-220 ◽  
Author(s):  
Chun-Hai Wei ◽  
Xia Huang ◽  
Cheng-Wen Wang ◽  
Xiang-Hua Wen
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Transmembrane Pressure ◽  
Fouling Control ◽  
Submerged Membrane Bioreactor ◽  
Negative Effect ◽  
Sludge Particle ◽  
Carrier Volume ◽  
Suspended Carrier

In an attempt at membrane fouling control, a kind of cylindrical plastic suspended carrier was added in a submerged membrane bioreactor (SMBR) and its effect was investigated in this study. According to the transmembrane pressure (TMP) profiles and the sludge characteristics in comparative runs with and without suspended carriers, it was found that the suspended carriers added in SMBR had two effects on membrane fouling: one was the positive effect of mechanically scouring the membrane surface and the other was the negative effect of breaking up sludge flocs. Sludge particle size distribution change was mainly responsible. It was suggested to apply the suspended carrier at higher MLSS concentration and lower carrier dose based on the consideration for retarding sludge breakage caused by the carrier. The experiment was conducted under higher MLSS (8 g L−1) and lower carrier dose (carrier volume/total volume = 1%). The TMP increase was effectively retarded by added suspended carriers compared to the system without addition of the carriers. The effect of suspended carriers on membrane fouling at high MLSS concentration was verified.

A venturi device reduces membrane fouling in a submerged membrane bioreactor

2016 ◽  
Vol 74 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Necati Kayaalp ◽  
Gokmen Ozturkmen
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Oxygen Transfer Rate ◽  
Surface Cleaning ◽  
Aeration Rate ◽  
Transmembrane Pressure ◽  
Submerged Membrane Bioreactor ◽  
System A ◽  
Do Concentration

In this study, for the first time, a venturi device was integrated into a submerged membrane bioreactor (MBR) to improve membrane surface cleaning and bioreactor oxygenation. The performances of a blower and the venturi device were compared in terms of membrane fouling and bioreactor oxygenation. Upon comparing membrane fouling, the performances were similar for a low operation flux (18 L/m2.h); however, at a medium flux (32 L/m2.h), the venturi system operated 3.4 times longer than the blower system, and the final transmembrane pressure was one-third that of the blower system. At the highest flux studied (50 L/m2.h), the venturi system operated 5.4 times longer than the blower system. The most notable advantage of using a venturi device was that the dissolved oxygen (DO) concentration of the MBR was in the range of 7 to 8 mg/L at a 3 L/min aeration rate, while the DO concentration of the MBR was inadequate (a maximum of 0.29 mg/L) in the blower system. A clean water oxygenation test at a 3 L/min aeration rate indicated that the standard oxygen transfer rate for the venturi system was 9.5 times higher than that of the blower system.

Exerting ultrasound to control the membrane fouling in filtration of anaerobic activated sludge—mechanism and membrane damage

2008 ◽  
Vol 57 (5) ◽  
pp. 773-779 ◽  
Author(s):  
Xianghua Wen ◽  
Pengzhe Sui ◽  
Xia Huang
Keyword(s):  
Activated Sludge ◽  
Hydroxyl Radicals ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Chemical Interaction ◽  
Membrane Surface ◽  
Membrane Damage ◽  
Operational Conditions ◽  
Fouling Control ◽  
Cake Layer

In this study, ultrasound was applied to control membrane fouling development online in an anaerobic membrane bioreactor (AMBR). Experimental results showed that membrane fouling could be controlled effectively by ultrasound although membrane damage may occur under some operational conditions. Based upon the observation on the damaged membrane surface via SEM, two mechanisms causing membrane damage by exerting ultrasound are inferred as micro particle collide on the membrane surface and chemical interaction between membrane materials and hydroxyl radicals produced by acoustic cavitations. Not only membrane damage but also membrane fouling control and membrane fouling cleaning were resulted from these mechanisms. Properly selecting ultrasonic intensity and working time, and keeping a certain thickness of cake layer on membrane surface could be effective ways to protect membrane against damage.

scholarly journals Comparison of ferric chloride and aluminum sulfate on phosphorus removal and membrane fouling in MBR treating BAF effluent of municipal wastewater

2016 ◽  
Vol 7 (4) ◽  
pp. 442-448 ◽  
Author(s):  
Xin Li ◽  
Yali Liu ◽  
Fangfang Liu ◽  
Aimin Liu ◽  
Qilan Feng
Keyword(s):  
Ferric Chloride ◽  
Membrane Fouling ◽  
Phosphorus Removal ◽  
Aluminum Sulfate ◽  
Municipal Wastewater ◽  
Transmembrane Pressure ◽  
Particle Sizes ◽  
Fouling Control ◽  
Aerated Filter ◽  
Sludge Particle

A membrane bioreactor (MBR) was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP) removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS) concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

Membrane fouling control in anaerobic submerged membrane bioreactor

2013 ◽  
Vol 52 (40-42) ◽  
pp. 7520-7530 ◽  
Author(s):  
Mustafa Aslan ◽  
Yusuf Saatçi ◽  
Özge Hanay ◽  
Halil Hasar
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Fouling Control ◽  
Submerged Membrane Bioreactor

Effect of Modified Diatomite Addition on Sludge Properties for Membrane Fouling Alleviation in Submerged Membrane Bioreactor

2011 ◽  
Vol 233-235 ◽  
pp. 680-683
Author(s):  
Shuo Liu ◽  
Yan Ping Liu ◽  
Bao Zhen Wang ◽  
Ji Fu Wang
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Submerged Membrane Bioreactor ◽  
Sludge Properties ◽  
Sludge Particle ◽  
Modified Diatomite

To alleviate the membrane fouling in membrane bioreactor, a kind of modified diatomite was used as anti-fouling agent to examine the effect on sludge properties in submerged membrane bioreactor for synthetic domestic wastewater treatment. Three submerged membrane bioreactor setups were operated under fixed membrane flux 21.9m3/m2·h, meanwhile, modified diatomite was added into each membrane bioreactor with dosage of 0mg/L, 1000mg/L and 2000mg/L respectively. Sludge particle size, extracellular polymeric substances and molecular weight distribution were characterized as the activated sludge properties in this study. The experiment results showed that with the increase of modified diatomite dosage, the number of sludge particle size less than 10μm was declined, however, the number between 10–20μm was increased correspondingly. Total extracellular polymeric substances and big molecular weight substances were decreased remarkably with modified diatomite addition dosage of 1000mg/L. The results indicated that addition of modified diatomite could effect of sludge properties in submerged membrane bioreactor. Therefore, membrane filtration performance could be improved by modified diatomite adding which alleviate membrane fouling directly.

Kinetic estimation of low excess sludge and extracellular polymeric substance accumulation in a vertical submerged membrane bioreactor (VSMBR)

2006 ◽  
Vol 1 (3) ◽  
Author(s):  
S.R. Chae ◽  
H.S. Chin
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substance ◽  
Membrane Bioreactor ◽  
Transmembrane Pressure ◽  
Yield Coefficient ◽  
Excess Sludge ◽  
Glucose Yield ◽  
Submerged Membrane Bioreactor ◽  
Polymeric Substance ◽  
Micro Organisms

The main objective of this study was to investigate reasons of mitigated membrane fouling based on a mathematical prediction of daily excess sludge (DES) and extracellular polymeric substance (EPS) accumulation in a laboratory-scale vertical submerged membrane bioreactor (VSMBR) fed with glucose. Yield coefficient, growth rate, and decay rate of autotrophic and heterotrophic micro-organisms were estimated by measuring oxygen uptake rate (OUR). From kinetic estimation, it was concluded that the DES from the VSMBR was only 4% of the total DES produced by the activated sludge process (ASP). This resulted from the lower yield biomass and the higher decay of heterotrophic biomass in the VSMBR. In part of the experiment, transmembrane pressure (TMP) was affected by a rapid increase in EPS concentration. Later, a second rapid increase of TMP was observed although EPS concentration was stable indicating that the second increase of TMP was caused by interfiber clogging other than EPS accumulation.

scholarly journals Effect of Mixed Liquor Volatile Suspended Solids on Membrane Fouling During Short and long-term Operation of Membrane Bioreactor

2015 ◽  
Vol 11 (21) ◽  
pp. 137-155 ◽  
Author(s):  
Edson Baltazar Estrada-Arriaga ◽  
Petia Mijaylova Nacheva ◽  
Liliana García-Sánchez
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Membrane Surface ◽  
Waste Water Treatment ◽  
Critical Flux ◽  
Term Operation ◽  
Mixed Liquor ◽  
Submerged Membrane Bioreactor ◽  
The Impact

The aim of this study was to examine the impact of different Mixed Liquor Volatile Suspended Solids (MLVSS) concentrations on membrane fouling,in a submerged Membrane Bioreactor (MBR) at short and longterm MBRoperation for waste water treatment. Three laboratory-scale in a submerged MBR system were operated under critical flux, subcritical flux,and an intermittent suction time and backwashing conditions. At short-term MBR operation with mixed liquors of 4,200 and 6,150 mg MLVSSL−1, the hydraulic resistance of membranes followed a same trajectory with averages of 5.0E+12m−1, whereas for 7,940 mg MLVSSL−1, a highresistance of up to 1.7E+13m−1was obtained. The result showed thathigh biomass concentrations decreased to permeability due to a bio-layer formed in the membrane surface and high Extracellular Polymeric Substance (EPS).

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