Critical review on microbial fuel cells for concomitant reduction of hexavalent chromium and bioelectricity generation

Rapid urbanization and industrialization has led to the indiscriminate discharge of heavy metals into the environment. Hexavalent chromium (Cr(VI)), a lethal, carcinogenic and genotoxic heavy metal frequently found in industrial effluent, poses a serious threat to human health. On the other hand, there is a global energy crisis prevalent owing to the scarcity of resources and huge energy demand. An emerging innovative technology which utilizes the biocatalytic activity of microbes for electron production and offers a dual solution for simultaneous reduction of Cr(VI) and generation of bioelectricity is the microbial fuel cell (MFC). The success of the MFC depends on variables such as cell configuration, pH, electrode materials, effect of microbial communities and operational conditions. This review provides a critical insight on the developments in the field of MFCs with abiotic and biotic cathodes, integrated systems, plant‐ and soil‐based designs for treatment of Cr(VI)‐laden effluent and sustainable energy recovery. © 2019 Society of Chemical Industry