Integration of Bioleaching and Biorefinery Technologies for the Recovery of Base and Critical Elements from Electronic Waste

Several profound societal changes such as the shift towards renewable energies have created an ever-increasing demand for base and critical metals. Electronic wastes constitute a significant secondary source of such elements and a potential environmental hazard if disposed of improperly. In contrast to traditional methods of recycling e-waste, biohydrometallurgy is an environmentally friendly, low-cost, and energy-efficient alternative. Although processes developed in laboratories display promising yields, it is still premature to implement these biotechnological strategies on a larger scale as the bioleaching and biorefinery mechanisms are still poorly understood. Moreover, very few studies focus on fully biological processes, and most opt for more efficient hybrid approaches. Thus, this book chapter compiles the optimal parameters reported in recent studies, from waste pre-treatment to metal biorecovery, along with insights to complete and close the biohydrometallurgical recycling loop.