scholarly journals Energy consumption in terms of shear stress for two types of membrane bioreactors used for municipal wastewater treatment processes

2012 ◽  
Vol 33 (2) ◽  
pp. 85-106 ◽  
Author(s):  
Nicolas Ratkovich ◽  
Thomas R. Bentzen ◽  
Michael R. Rasmussen
Keyword(s):  
Shear Stress ◽  
Energy Consumption ◽  
Municipal Wastewater ◽  
Bubble Column ◽  
Membrane Surface ◽  
Empirical Relationship ◽  
Membrane Bioreactors ◽  
Experimental Measurements ◽  
Municipal Wastewater Treatment ◽  
Cfd Modelling

Abstract Two types of submerged membrane bioreactors (MBR): hollow fiber (HF) and hollow sheet (HS), have been studied and compared in terms of energy consumption and average shear stress over the membrane wall. The analysis of energy consumption was made using the correlation to determine the blower power and the blower power demand per unit of permeate volume. Results showed that for the system geometries considered, in terms the of the blower power, the HF MBR requires less power compared to HS MBR. However, in terms of blower power per unit of permeate volume, the HS MBR requires less energy. The analysis of shear stress over the membrane surface was made using computational fluid dynamics (CFD) modelling. Experimental measurements for the HF MBR were compared with the CFD model and an error less that 8% was obtained. For the HS MBR, experimental measurements of velocity profiles were made and an error of 11% was found. This work uses an empirical relationship to determine the shear stress based on the ratio of aeration blower power to tank volume. This relationship is used in bubble column reactors and it is extrapolate to determine shear stress on MBR systems. This relationship proved to be overestimated by 28% compared to experimental measurements and CFD results. Therefore, a corrective factor is included in the relationship in order to account for the membrane placed inside the bioreactor.

Dimensioning of membrane bioreactors for municipal wastewater treatment

2008 ◽  
Vol 57 (6) ◽  
pp. 829-835
Author(s):  
Detlef Wedi ◽  
Adriano Joss
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Municipal Wastewater Treatment ◽  
Hydraulic Loading ◽  
Basic Procedure

A basic procedure is proposed for dimensioning membrane bioreactors that is generally applicable. It evaluates the required membrane surface with particular consideration of loading combinations and hydraulic loading characteristics; it also takes into account ranges of minimum temperatures and corresponding fluxes as given by suppliers. The procedures, while likely to require further improvement, should make MBR design more transparent and aid the comparison of design variants

Membrane Bioreactors for Municipal Wastewater Treatment

2015 ◽  
Vol 4 (0) ◽  
pp. 9781780402925-9781780402925
Author(s):  
H. van der Roest ◽  
D. Lawrence ◽  
A. van Bentem
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Municipal Wastewater Treatment

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.

An optimal solution to achieve the energy neutral Waste Water Treatment Plant

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
Christophe Amiel ◽  
Delphine Nawawi-Lansade ◽  
Kim Sorensen
Keyword(s):  
Energy Consumption ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Waste Water Treatment ◽  
Carbon Sources ◽  
Treatment Plant ◽  
Co2 Reduction ◽  
Optimal Solution ◽  
Waste Water Treatment Plant ◽  
Municipal Wastewater Treatment

Many recent studies have shown processes or models to minimize the energy consumption on a municipal wastewater treatment plant (WWTP) in operation. Today the main drivers are the energy and CO2 reduction. On existing plants, the potential success of achieving the Energy neutral WWTP depends on the effluent guarantees demanded and the eventual additional carbon sources on the digesters. Veolia has now developed a tool to estimate the energy consumption and the CO2 impact to select the appropriate treatment lines (water and sludge) up front at the project stage. The real challenge is to cover the needs of the plant without external carbon sources added to the digester. At the project stage, before the bid of the WWTP, due to time constraints only few comparisons can be performed to predict the energy consumption and CO2 impact and provide the best solution to reach to the energy neutral plant as electricity wise. One conclusion of the study is that, the raw water characteristics and the effluent guarantee has a great impact on the possibilities to reach the target. Furthermore, working on reducing the power consumption and on increasing the biogas production for example by a continuous Thermal hydrolysis is a good way to go towards self sufficiency.

A practitioner’s perspective on the application and research needs of membrane bioreactors for municipal wastewater treatment

2012 ◽  
Vol 122 ◽  
pp. 2-10 ◽  
Author(s):  
Jeremy T. Kraemer ◽  
Adrienne L. Menniti ◽  
Zeynep K. Erdal ◽  
Timothy A. Constantine ◽  
Bruce R. Johnson ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Research Needs ◽  
Municipal Wastewater Treatment

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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