Phototrophic microbial fuel cells: a greener approach to sustainable power generation and wastewater treatment

Abstract

Microbial fuel cells (MFCs) rely on the capacity of electrode-adhered electroactive bacteria to oxidize organic matter and generate electrons. Typical MFCs are highly engineered systems that can be applied as green tools to alleviate the burden of waste streams. Phototrophic MFCs (PhMFCs) are a promising variant that can be implemented indoors or outdoors and use the power of the sun to boost efforts in on-site environmental remediation, biomass generation, and power generation. PhMFC variations include plant-based and algal-based MFCs. Algal-based MFCs can incorporate special photosynthetic action at either the anode or cathode, enhancing or replacing the role of other bacteria in regular bacterial MFCs. Plant-based MFCs can be more complex due to the role of the root system near an electrode and its interaction with electrode-adhered bacteria, and they are nearly universally operated outdoors in either natural or engineered conditions. This review emphasizes the potential of phototrophic MFCs in achieving true carbon neutrality, producing bioelectricity, and detecting toxic substances in wastewater sources. It also identifies gaps, such as the need for certain optimizations, coupling with new enabling technologies and the potential for combining photosynthetic microbes and plants into the same system. Overall, the future prospects for phototrophic MFCs to contribute to sustainable wastewater treatment and energy generation are promising.