An overview of agro-industrial wastewater treatment using microbial fuel cells: Recent advancements

Discharge of agro-industrial wastewater causes severe damage to the environment due to the various hazardous components it contains. Progressive circular agriculture and industry involve closed cycles and zero-waste principles; therefore, waste treatment for subsequent reuse is of great interest. The microbial fuel cell (MFC) is a promising sustainable technology capable of treating wastewater at low cost without greenhouse gas (GHG) emissions while simultaneously producing electricity. The principle behind MFCs is based on the conversion of chemical energy into electricity using electrochemically active bacteria (EAB) as a biocatalyst. This article presents an overview of the progress and recent advancements in MFCs as a pivotal technology for agroindustrial wastewater treatment with production of sustainable electricity, compared to conventional treatment processes. Furthermore, the fundamental aspects of the design, configuration, operation, and application of MFCs in wastewater treatment (i.e., removal of inorganic nutrients, nitrate, phosphate, sulfate, sulfide, ammonium, organics, dyes, carbohydrates, fatty acids, and petroleum) are comprehensively discussed. Despite the viability and potential of MFCs in treating agro-industrial wastewater and producing electricity, they face various limitations and significant challenges, which are highlighted in this review. Future opportunities and perspectives on MFC applications are also discussed. Further research is required to address MFC limitations, which could make them feasible and practicable for real-world applications. However, MFC technology is clearly an excellent option for simultaneous wastewater treatment and electricity production without the need for external energy sources.