Harnessing Bioelectrochemical Systems for Metal Dissolution: Advances in Sustainable Recovery

The growing demand for critical metals has intensified the search for sustainable and resource-efficient extraction and recovery technologies. Although conventional pyrometallurgical and hydrometallurgical processes remain the dominant industrial approaches, they are often associated with high energy requirements, extensive chemical consumption, and considerable environmental impacts. Bioleaching has emerged as a promising alternative, enabling the microbial solubilization of metals from a wide range of solid matrices under comparatively mild operating conditions. More recently, bioelectrochemical systems (BES) have gained increasing attention as an innovative platform that integrates microbial metabolism with electrochemical control to enhance metal recovery processes. By harnessing the activity of electroactive microorganisms within electrochemical reactors, BES can accelerate redox reactions, improve metal dissolution rates, and promote selective recovery pathways. This additional level of control represents a significant advancement over conventional bioleaching technologies and creates new opportunities for the valorization of low-grade ores, electronic waste, and industrial residues. Furthermore, BES can reduce dependence on aggressive chemical reagents while supporting energy-efficient operation through mechanisms such as electricity generation in microbial fuel cells (MFCs) and low-voltage-driven metal recovery in microbial electrolysis cells (MECs). This review critically examines recent advances in BES-assisted metal recovery, with particular emphasis on their integration with bioleaching strategies. Key challenges and future research directions are also discussed, including the mechanistic understanding of microbe–electrode interactions, the development of advanced electrode materials, process intensification, and the scale-up of BES technologies for sustainable metallurgy and circular economy applications.