Bio-Extraction of Metals as Secondary Resources from E-Waste

Abstract

Electronic waste is widespread across the globe comprises wide range of elements, growing exponential recent years and even categorized as hazardous if the elements like lead, mercury, arsenic, cadmium, selenium, and hexavalent chromium etc. are present beyond the permissible quantities. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals. Bio-extraction of metals from E-waste with microbes such as bacteria and fungi is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the biological extraction techniques including an assessment has been made to quantify the different E-waste and their metal compositions, microbes used, metal leaching efficiency etc. and proposes that the biological recovery allows the cycling of metals by a process close to natural biogeochemical cycles reducing the demand for resources such as ores, energy, or landfill space.