A review of electro-conductive membrane enabled electrochemical anaerobic membrane bioreactor process for low-carbon wastewater treatment

Membrane fouling poses a great challenge for practical application of the promising anaerobic membrane bioreactor (AnMBR) process treating organic wastes and wastewater. The integration of electrically conductive membrane with AnMBR process is an innovative practice for simultaneously enhancing pollutants removal and fouling mitigation. This review presents an overview on electro-conductive membrane enabled electrochemical anaerobic membrane bioreactor (AnEMBR) process, with the focus on the fabrication and modification of conductive membranes, process performance enhancement, and antifouling properties. With the assistance of various organic polymeric, inorganic and composite conductive membranes, the AnEMBR can be steadily applied for municipal and industrial wastewater treatment, showing enhanced pollutants removal and methane production as well as reduced fouling propensity. The improved organics removal and biogas production are due to electrochemically improved selectivity, enrichment of electroactive bacteria as well as altered methanogenic pathways. Since the conductive membranes can serve as the anode or cathode, the bio-electrochemically induced fouling control mechanisms are mainly attributed to sludge properties modification, in-situ hydrogen gas generation and scouring, electrostatic repulsion, direct and indirect electro-oxidation. Future perspectives include high-quality electrodes development, value-added resource recovery, emerging contaminants removal as well as advanced modelling and system analysis, which will promote large-scale implementation of the AnEMBRs for low-carbon wastewater treatment.