Membrane filtration of wastewater accompanies formation of cake layers in membrane bioreactor (MBR) systems. The cake layer has been thought to cause flux decline in MBR for treating various wastewaters under different operating conditions, whereas several recent investigators reported that the cake layer on the membrane surface could enhance permeability as a dynamic (or secondary) membrane. However, there is little information available on the dynamic membrane in MBR, and the findings are controversial. This study investigated dominant factors contributing to form the dynamic membrane on submerged membranes through microfiltration of activated sludge in MBRs with solid retention time (SRT) of 20, 40 and 60 days. MBRs with higher microbial concentrations exhibited better permeability than lower ones, resulting in formation of more dynamic membranes. Size of particulates and colloids appeared a key parameter for the formation of dynamic membranes in the MBR systems.
This presentation is available to AMTA Members only.
- Wontae Lee
- Kumoh National Institute of Technology
- AWWA/AMTA Membrane Technology Conference, Glendale, AZ
- AWWA/AMTA Membrane Technology Conference
- Formation, Submerged, Bioreactors