2023 Volume 79 Issue 25 Article ID: 23-25014
High-rate membrane bioreactor (HR-MBR) can recover >80% of organic matter in municipal wastewater and simultaneously achieve high-quality effluent (>90% removal of COD) However, extremely severe membrane fouling is expected in the operation of HR-MBRs due to very short sludge retention times (SRTs) such as 1 day. In this study, to tackle with the severe fouling in HR-MBRs, intensive physical cleaning with granular materials and chemically enhanced backwashing (CEB) were applied. Influences of different types of granule materials and frequency of CEB on the membrane fouling in HR-MBR was investigated. Sponge cubes exhibited excellent control of reversible fouling in an HR-MBR treating real municipal wastewater. The HR-MBR could be stably operated for 30 days under a membrane flux of 20 LMH (0.48 m/d), which is comparable to that set with conventional aerobic MBRs. It was also demonstrated that frequent CEB tended to accelerate membrane fouling in the HR-MBR.
