Recovery of Precious Metals from Electronic and Other Secondary Solid Waste by Bioleaching Approach

E-waste is considered to be an emerging global issue, the bulk of which is generated in Asia and then followed by the other continents. Inappropriate handling and recycling of e-wastes containing heavy metals, halogenated compounds, and radioactive substances can affect the environment. E-wastes when burnt in an open environment produce dioxins and polycyclic aromatics that are highly harmful and toxic in comparison to compounds produced during the burning of domestic waste. Bioleaching is the most effective and sustainable approach to meet the needs of future with respect to e-waste treatment and management. Bioleaching refers to the usage of naturally occurring microorganisms for the solubilization of metals from insoluble secondary wastes for its subsequent extraction. The development of molecular biology techniques has enabled the identification of microbes and deepened our knowledge about the role of microbes and its interaction in extraction of metal. This in turn has opened up new possibilities and in the application of biomining of e-waste.