Biological approaches to mitigate heavy metal pollution from battery production effluents: advances, challenges, and perspectives.

Battery production generates effluents containing various pollutants, predominantly heavy metals such as lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), zinc (Zn), and chromium (Cr), which represent a serious risk to human health and the environment. Given their persistence, toxicity, and mobility in ecosystems and biota, heavy metals can bioaccumulate and, in some cases, enter the food chain. With this context in mind, this review presents emerging bioremediation technologies to treat effluents from battery production, focusing on biological methods such as biosorption, phytoremediation, and the use of microorganisms. Heavy metal removal mechanisms and conventional treatments are reviewed, with emphasis on biological approaches. Biosorption emerges as the most used strategy (54.4%) across organisms from different kingdoms. In addition, existing knowledge gaps in battery industry effluent management research are identified, proposing future directions that include the integration of sustainable technologies and the use of traditional knowledge of local communities. This approach seeks not only to mitigate the environmental impact of battery production but also to promote more responsible and equitable production practices, aligned with the principles of environmental justice and sustainability.