Possible bio cathode materials for usage in microbial fuel cells towards energy generation and wastewater treatment to sustain environment: A review

The aim of this study is to review the effectiveness of bio-cathode materials usage in microbial fuel cells (MFCs) for power generation and wastewater treatment. The review focused on the Microbial fuel cell construction and design. The Anode and cathode materials of MFCs with their merits and demerits are compared. The first half of the study discusses the components for Anodes and cathodes. Typical anode and cathode materials are compared based on their power densities. The focus is narrowed down to discuss about bio cathode components and their materials including the most prominent/discussed ones such as Stainless steel and Graphite/carbon as bio cathode materials. Indirect electron transfer and direct electron transfer in MFCs are also reviewed. The second part of the review focused on bio cathode materials for electricity production and wastewater treatment. It was reported in many literatures that, MFCs can serve as supplementary, decentralized power sources. Also this review highlighted that MFCs can be employed with effective methods for removing sulfides from wastewater
with certain microbes. It was reported that, a considerable coulombic efficiency of 80% can be achieved with MFCs. It was also found from the literatures that a well-designed MFC-membrane bioreactor for wastewater treatment could achieve good pollutant removal performance with a remarkable power density of 6 W/m3 at an average current of 0.4 mA to 1.9 mA. The limitations of current technology, as well as some possible future developments, were discussed in the last section. Therefore, this may open up possibilities for further development and the use of bio-cathode materials in the future.