Biometallurgical Recovery of Metals from Waste Electrical and Electronic Equipment: a Review

The feasibility of biometallurgical processing for recovering heavy metals, precious metals, and rare earth elements from waste electrical and electronic equipment (WEEE) is critically reviewed. An overview of past achievements, present scenarios, and future prospects of these techniques is given. The potential of various lithotrophic and organotrophic microorganisms is particularly highlighted for extracting metals by producing inorganic and organic acids in the process. The metal-binding ability of various biomaterials including algae, fungi, bacteria, and yeast as well as certain biopolymers and bio-waste materials is reviewed in view of recovering metals from WEEE. Due to the increasing importance of heavy and precious metals and rare earth elements in the transition to a green energy economy based on high-tech applications, coupled with the shortage of economical and/or operational primary deposits, a substantial improvement in the recycling of WEEE for recovery of metals is therefore an absolute necessity. This can only be realized by developing efficient and fully integrated recycling routes. Current work also focused on most probable recycling routes, with an emphasis on the state of the art in bioprocessing of WEEE.