Integrated powdered activated carbon and quorum quenching strategy for biofouling control in industrial wastewater membrane bioreactor

Microbial quorum quenching (QQ) has been shown as a promising technology for biofouling control in membrane bioreactors (MBRs). However, QQ technology has never been applied in the industrial wastewater MBR due to the complex water properties. In this study, a type of novel alginate (polyvinyl alcohol)-powdered activated carbon-quorum quenching bacteria beads (APQ beads) was introduced, and the anti-biofouling potential was investigated in an MBR treating semi-conductor wastewater (rich in ethanolamine and diethylene glycol butyl ether). The results show that APQ strategy could significantly alleviate MBR biofouling by extending 4.5 times operating period as compared to the Control-MBR (R1) without APQ beads. The APQ strategy effectively reduced the extracellular polymeric substance (EPS) content and N-acyl homoserine lactones (AHL) concentration in biocake. EPS concentration was reduced by 33.8% and AHLs almost disappeared, probably retarded the adhesion rate of biofilm on the membrane surface, thus displayed a high biofouling mitigation potential. With APQ addition, cake layer membrane resistance was also greatly reduced by 37.22% compared to that of Control-MBR (R1). The QQ activity batch tests confirmed that the used APQ beads still displayed a high AHL-degrading activity and can be employed for long-term operation.