Bioelectrochemical energy conversion and wastewater treatment in microbial fuel cells: a review of progress, limitations, and future developments

Energy dependence within a society serves as a fundamental metric for assessing civilizational advancement, and with the progressive depletion of fossil fuels and conventional energy resources, innovative technologies become imperative for achieving sustainable energy solutions. Among the most promising technological innovations addressing global energy demands is the Microbial Fuel Cell (MFC), which demonstrates the capacity to produce electrical energy through the utilization of carbon-based substrates. MFCs present significant advantages for decentralized energy infrastructure and waste treatment strategies by simultaneously facilitating wastewater remediation while generating bioenergy output. Recent advancements in synthetic biology and microbial engineering have enhanced the stability of biofilms and improved the transfer of extracellular electrons. The use of nanostructured electrodes has led to increased current output compared to conventional carbon electrodes. However, challenges persist, including high material costs, electrode fouling, limited long-term stability, and scaling issues that impede industrial deployment. This comprehensive review examines recent technological progress, existing challenges, prospective applications of MFCs within the framework of environmental sustainability and renewable energy generation. The review analyzes recent advancements in microbial optimization, electrode innovation, and reactor design. It highlights the remaining challenges in maximizing power generation and reducing production costs. These developments aim to advance MFCs toward practical large-scale applications in both environmental and energy sectors.