An overview of bioprocess based recovery and recycling techniques for battery waste management: Transitioning from environmental hazard to sustainability

Battery waste poses ecological, economic and health risks due to rising usage and improper disposal. Accumulation in landfills releases toxic compounds, while valuable metals remain unrecycled. Conversely, battery waste is also characterized as secondary resource because it has a higher metal content than primary ores. Conventional approaches, such as pyrometallurgy and hydrometallurgy are expensive, energy intensive, and polluting. This shift highlights the need for sustainable resource management to recover constituents from spent battery materials, as depletion of metallic resources is one of the most critical environmental and socioeconomic concerns Bioprocesses such as bioleaching, biosorption, biomineralization and bio-electrochemical systems are highlighted in this review as sustainable, selective recovery alternatives. This review explores the dual role of agricultural waste for waste valorization and metal extraction aligning with circular economy principles. Mechanistic understanding of microbe-metal and agricultural waste interactions is discussed in detail, emphasizing on sequential integration of bioprocesses, hybrid systems combining bioprocesses with conventional techniques and improving recovery efficiency. Progress, challenges and barriers in scalability are discussed, addressing toxicological concerns of emerging battery contaminants. The review promotes bio-based eco-friendly recovery processes, with vision to achieve reduced environmental impact, improved metal recovery and efficient integration of circular economy of resources.