Anaerobic electrochemical membrane bioreactors: A panoramic tool for wastewater treatment and resource recovery

Anaerobic electrochemical membrane bioreactor (AnEMBR) is to combine anaerobic membrane bioreactor with electrochemical technology. Elucidating the mechanisms of methane production kinetics and membrane fouling under electric field has been an area of intense research interest in AnEMBR. In wastewater treatment and resource recovery, the AnEMBR has been proven as a promising technology especially to overcome technical limitations confronted by conventional AnMBR system. For example, the methane production rate can be 20-50% faster under the external voltage less than 1.0 V into the AnEMBR than that without electric field. Efficient mitigation of membrane fouling also can be achieved by using the concepts of electrostatic interactions between foulants and conductive membrane or electrode materials. In this review, the fundamental aspects of methane production rate and fouling control by AnEMBR systems are discussed by critical review emphasizing reactor configurations, selection of electrode/membrane materials, and operating parameters. Furthermore, the impacts of electrochemical processes on microbial activity and the underlying mechanism occurring in the AnEMBR systems are discussed. The effects of alterations in the microbial community on reactor performance and energy recovery from the AnEMBRs are examined. Finally, suggestions to overcome current limitations faced by the AnEMBR are provided. Cutting-edge data presented in this study has the great potential to broaden the focus of translational and transdisciplinary studies on the AnEMBR as innovative technology for sustainable wastewater treatment and resource recovery.