Effect of activated sludge properties and membrane operation conditions on fouling characteristics in membrane bioreactors

Chemosphere ◽  
2006 ◽  
Vol 63 (10) ◽  
pp. 1699-1708 ◽  
Author(s):  
Hyeok Choi ◽  
Kai Zhang ◽  
Dionysios D. Dionysiou ◽  
Daniel B. Oerther ◽  
George A. Sorial
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactors ◽  
Operation Conditions ◽  
Sludge Properties ◽  
Fouling Characteristics

Identification of activated sludge properties affecting membrane fouling in submerged membrane bioreactors

2006 ◽  
Vol 51 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Fangang Meng ◽  
Hanmin Zhang ◽  
Fenglin Yang ◽  
Shoutong Zhang ◽  
Yansong Li ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Sludge Properties

scholarly journals Correction: Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters

2021 ◽  
Author(s):  
Ling Luo ◽  
Hui Zhong ◽  
Ye Yuan ◽  
Wenwang Zhou ◽  
Changming Zhong
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Operating Parameters ◽  
Salinity Shock ◽  
Fouling Characteristics

Correction for ‘Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters’ by Changming Zhong et al., Environ. Sci.: Water Res. Technol., 2021, DOI: .

Study of Flocculation Mechanisms by Observing Effects of a Complexing Agent on Activated Sludge Properties

1991 ◽  
Vol 24 (7) ◽  
pp. 21-28 ◽  
Author(s):  
L. Eriksson ◽  
B. Alm
Keyword(s):  
Activated Sludge ◽  
Metal Ions ◽  
Electrostatic Interactions ◽  
Wastewater Treatment Plants ◽  
Sedimentation Velocity ◽  
Complexing Agent ◽  
Extracellular Polymers ◽  
Filtration Resistance ◽  
Polyvalent Metal ◽  
Sludge Properties

Electrostatic interactions between bacterial surfaces, extracellular polymers (ECP) and polyvalent metal ions are important in activated sludge flocculation. An indirect study of these mechanisms was done by adding different concentrations of EDTA to activated sludge samples from 6 Swedish wastewater treatment plants. The effects on sludge properties were studied with sedimentation and filtration tests as well as analysis of released extracellular polymers. EDTA had a significant effect on sedimentation velocity in all investigated sludges. This shows that charged polymers are important for the properties of the floc surfaces and in building up the sludge macroflocs. The effect on filtration resistance where the bulk properties of the primary flocs are more important varied considerably for the different sludges. Thus, both electrostatic and other interactions are involved to a varying extent in building up the primary flocs in the sludges investigated. Variations in sedimentation velocity, residual turbidity, filtration resistance and release of ECP with variations in EDTA concentrations could be explained by effects of polyvalent metal ions on ECP binding and conformation.

The importance of measuring the sludge filterability at an MBR – introduction of a new method

2012 ◽  
Vol 66 (1) ◽  
pp. 9-14 ◽  
Author(s):  
C. Thiemig
Keyword(s):  
Membrane Fouling ◽  
Reliable Method ◽  
Membrane Bioreactors ◽  
New Method ◽  
Strong Impact ◽  
Laboratory Equipment ◽  
Filtration Performance ◽  
Sludge Properties ◽  
Operational Aspects ◽  
General Method

Sludge properties have a strong impact on the operational aspects of membrane bioreactors (MBRs). Poor sludge properties cause stronger membrane fouling and reduce the filtration performance of MBRs. Up to now there is no general method used to measure the fouling or filtration relevant sludge properties in MBRs. The aim of this work was to develop a simple but reliable method to supply operators a tool to monitor the important sludge properties for their application and to compare this method with existing techniques. Through extensive research a new method called the sludge filtration index (SFI) has been developed to indicate the appropriate sludge parameters for MBR systems in a cheap and easy manner. The SFI can be measured with simple laboratory equipment and offers operators a powerful tool to monitor the conditions of their sludge, independent of the membrane conditions.

Effects of potassium ion on sludge settling, dewatering and effluent properties

1998 ◽  
Vol 37 (4-5) ◽  
pp. 317-324 ◽  
Author(s):  
Sudhir N. Murthy ◽  
John T. Novak
Keyword(s):  
Activated Sludge ◽  
Field Studies ◽  
Potassium Ion ◽  
Potassium Ions ◽  
Nutrient Requirements ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Flocs ◽  
Sludge Properties ◽  
Sludge Settling

Potassium ions appear to play an important role in determining the nature of activated sludge flocs. Relative to sodium, the concentration of potassium ions in most industrial activated sludge is typically low. Laboratory and field studies were conducted to examine the influence of potassium on activated sludge properties. The concentration of potassium affected the concentration of readily extractable (slime) proteins in the floc and the proteins in the surrounding solution. In laboratory tests, an increase in this cation's concentration beyond nutrient requirements impeded sludge dewatering properties as measured by capillary suction time (CST) and specific resistance to filtration (SRF) and associated with an increase in soluble protein. An increase in effluent total organic carbon and effluent turbidity was observed at higher concentrations of this ion. Conversely, an increase in concentration of potassium ion improved the settling properties of sludge with low equivalent monovalent to divalent cation ratio.

Impact of a metabolic uncoupler, 2,4-dichlorophenol on minimization of activated sludge production in membrane bioreactor

2010 ◽  
Vol 62 (6) ◽  
pp. 1379-1385 ◽  
Author(s):  
Lin Song ◽  
Jiang Wenju ◽  
Tang Qiong ◽  
Li Yaozhong
Keyword(s):  
Activated Sludge ◽  
Specific Growth ◽  
Removal Rate ◽  
Significant Inhibition ◽  
Membrane Bioreactors ◽  
Cod Removal ◽  
Slight Reduction ◽  
Floc Size ◽  
Cod Removal Rate ◽  
Sludge Production

This study investigated the effects of 2,4-dichlorophenol on reduction of activated sludge in membrane bioreactors. Significant inhibition on sludge growth and slight reduction in COD removal were observed at higher 2,4-dichlorophenol dosages. The deviation between relative specific COD removal rate (q/q0) and relative specific growth rate (μ/μ0) suggested that a minimum 2,4-dichlorophenol concentration was required for uncoupling of anabolism and catabolism. With the increase of the dosage of 2,4-dichlorophenol, stepwise improvement of biomass bioactivity and the reduction in activated sludge production were achieved simultaneously. Compared with the control bioreactor, the peak distribution of floc size in the 2,4-dichlorophenol added bioreactor shifted to a range of smaller floc size. Besides, addition of 2,4-dichlorophenol caused little variation of microorganism community structure and SVI value of the sludge. After 24-hour operation, the residue 2,4-dichlorophenol concentration in the bioreactors was reduced to a negligible level.

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.

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