Chapter 11 - Bioelectrochemical reduction of heavy metals from industrial effluents

Abstract

Heavy metal contamination in industrial effluents poses serious threat to the environment and human health. Traditional heavy metal removal techniques, including chemical precipitation and adsorption, are frequently expensive and energy-intensive and produce a lot of chemical sludge. Recent years have seen the emergence of bioelectrochemical systems (BESs), primarily microbial fuel cells (MFCs), as a viable sustainable method for reducing heavy metals from industrial effluents and producing electricity simultaneously. In MFCs, both abiotic and biotic cathodes have demonstrated the ability to remove heavy metals. Biotic cathodes employ microorganisms to facilitate the removal of heavy metals through processes such as biotransformation and bioaccumulation. On the other hand, abiotic cathodes depend on physicochemical mechanisms including adsorption, precipitation, and electrochemical reduction to remove heavy metals from the system. The current understanding of heavy metal removal at abiotic and biotic cathodes in MFCs is highlighted in the chapter. BESs utilize the unique properties of microorganisms and electrochemistry to achieve efficient and environmentally friendly heavy metal removal. The mechanisms underlying heavy metal reduction in BESs, such as microbial metabolism, and electrochemical reduction are discussed. The advantages of BESs include high removal efficiency, low energy consumption, and minimal chemical sludge generation. Overall, this chapter provides a comprehensive overview of the current state of knowledge on heavy metal removal in MFCs and highlights the potential of MFCs as a sustainable and effective technology for addressing heavy metal pollution in wastewater.