Pathway towards the commercialization of sustainable microbial fuel cell-based wastewater treatment technologies

Microbial fuel cells (MFCs) have emerged and implemented as eco-friendly technologies with the potential for simultaneous removal of contaminants from (waste)waters and generation of bioelectricity as a green and renewable source of energy. However, little evidence is available for large-scale applications of these technologies due to technical and economic issues related to the fabrication and performance of the MFC components (i.e., anode, cathode, and proton exchange membrane). Herein, numerous innovative approaches are discussed with the potential to (a) enhance the overall efficiency of MFCs for electricity generation and treatment of polluted streams and (b) reduce the costs of electricity generation with these technologies. In this regard, application of waste-driven carbonaceous structures (e.g., biochar, carbon nanotubes, and graphite-based materials), coupled with novel fabrication techniques such as three-dimensional (3-D) printing, are emphasized to develop cost-effective production of MFCs. The development of sustainable integrations of MFCs with technologies such as anaerobic digestion, constructed wetlands, and cathodic Fenton reactions are critically reviewed for practical applications of MFCs, especially in staked configurations to optimize electrical energy output. Novel applications of MFC-based technologies, such as household bioelectricity generation units, are discussed to mitigate pollutants in their generation source. Research opportunities are discussed to fill-up the existing gaps towards the implementation of MFCs in sustainable wastewater treatment applications.