An overview of membrane bioreactor coupled bioelectrochemical systems

Bioelectrochemical systems (BESs) have a unique ability of concomitant wastewater treatment and by-product development in view of electricity generation and valuables recovery. Though the BES technology has been extensively evaluated for the past two decades for scaling up, it is yet to be called a stand-alone unit for wastewater treatment and simultaneous valuables recovery and/or electricity generation. This is attributed to the various factors such as membrane cost, mass transport losses due to reactor size, lower product yield due to slow bio-mediated processes, and uncertainty of the microbial dynamics at the anode surface, which hinder the scale-up applications of it. The BES can be modified in agglomeration with other established technologies, such as membrane bioreactor (MBR), to remove specific pollutants and to recover electricity or synthesize other compounds that can be utilized on-site. The constraint of low yield of product (electricity or any valuables) can be overcome by this hybridization with enhanced wastewater treatment efficiency. Different approaches have been proposed for the combination of BES with MBR either in an integrated way, such as membrane filtration as a part of BES unit, or separate treatment unit till date. The investigations claim successful demonstration at bench/lab-scale level and address the removal of organics with enhanced power recovery and membrane fouling mitigation. This chapter is dedicated to the detailed overview of such hybrid systems with an aim to provide an idea to the researchers on future perspectives of these systems to take it to the commercial level.