Abstract
The use of membrane bioreactors (MBRs) is rapidly increasing in the field of organic wastewater treatment. In typical MBR applications for activated sludge processes, the aeration for oxygen supply is also used to maintain high cross-flow liquid velocity over the submerged membrane system (SMS). The prime objective of this study was to demonstrate the effect of presence of gas phase fraction in suspension on the performance of membrane filtration. Experimental studies were performed using two different membrane modules of (1) flat sheet membrane cell (FMC) operated outside the feed tank, where the cross flow velocity of liquid and the volume fraction of gas were changed independently, and (2) flat sheet SMS operated in tank. The relationship between the cross flow velocity, volume fraction of gas phase and the trans-membrane pressure (TMP) were determined. It was observed that the rate of increase in TMP did not depend on the presence of gas phase, but depended on the real cross-flow liquid velocity, uL', for both the FMC with and without gas phase and the flat-sheet SMS.
