A review of the factors affecting the performance of anaerobic membrane bioreactor and strategies to control membrane fouling

The performance of the different configurations of AnMBRs is affected by operating parameters including solid retention time (SRT), hydraulic retention time (HRT), organic loading rate (OLR), sludge recycle rate, temperature and wastewater characteristics. Generally, the optimum operating condition is characterized by a longer SRT and HRT, higher OLR at a mesophilic temperature range. These parameters also affect the propensity of membrane fouling which is considered as the major challenge limiting its sustainable use. Hence, these parameters need to be understood and optimized. The common fouling control strategies include sub-critical flux operation, membrane relaxation, backwashing, biogas sparging, sludge recycle and use of coagulants and turbulence promoters are inadequate in fully controlling the fouling process. Hence, new and emerging technologies like enzymatic or bacterial degradation through quorum quenching technology are being explored. Moreover, integration of rotary disks/membrane, attached growth system, dynamic membrane, electrochemical membrane and baffled reactor configurations are introduced as modifications to the conventional AnMBR. Review of these strategies reveal that these novel configurations of AnMBR and the use of quorum quenching technology offer a potential sustainable approach to fouling control, and hence should be explored further.