Membranes in bioelectrochemical systems: Current development, applications and classifications

The ever-increasing global population and urbanization have posed the challenge of enhanced energy requirements. Furthermore, the limitation of non-renewable sources has shifted the focus to renewable sources for energy production. One such renewable technology is the bio-electrochemical system that produces energy from wastewater. It has dual advantage of treating wastewater along with energy generation fulfilling both sustainable development goals 6 and 7. However, this novel technology depends on membrane for substrate separation. This has led to membrane being a significant part of bio-electrochemical system to enable higher end energy generation than possible today. Membrane properties like resistance, thickness, porosity, surface area, composition and chemistry all affect their ion conductivity and ion exchange capacity. This review thus provides an overview of the traditionally commonly used membranes in bio-electrochemical cells along with their limitation followed by a broader view of the recent advances in membrane research and use like biochar, bio-based, nanomaterial and metal organic framework-based membranes to mitigate the challenges and their practical applications in bio-electrochemical systems. The topics like membrane potential, membrane-microbe interaction, reusability and membranes in pilot scale bio-electrochemical cells that possess a research gap in the subject area are also discussed. • Membrane selection determines BES function and efficiency. • Membranes influence bacterial community and biofouling. • Scale-up BES are typically run with anion or cation exchange membranes. • Bio-based membranes are emerging sustainable alternatives in BES use. • Membrane cleaning and reusability need more research.