Recent advancements in sustainable approaches to recover precious metals from waste electrical and electronic equipment (WEEE)

Abstract

Due to the rapid growth of the world's population and the increased use of electronic/electrical equipment, millions of tonnes of WEEE are produced globally every year. WEEE has harmful substances such as plastics, metals, and refractory oxides. The rapid increase in the discharge of precious metals, concurrent with WEEE, raises growing concerns about environmental impacts, human health issues, and the depletion of natural resources. In this context, considering circular economy and sustainability, precious metal recovery has gained considerable attention from the scientific community in recent years. Solvent extraction and leaching are the main techniques for recovering metals from waste. Due to the challenges associated with conventional chemicals used in both techniques, it is a matter of concern to look into safer, cleaner, and greener chemicals used to recover precious metals. In a series of chemicals used so far, a new family of products, i.e., "Deep Eutectic Solvents" (DES), has gained consideration in contemporary years. This review covers a broader way to describe DESs and their characteristics, with the essentials as a substitute medium for recovering precious metals from WEEE, as there is only limited literature available that provides proper methods and strategies using DES for metal recovery. Herein, also report the framework towards the global eminence of WEEE and its contemporary advancement in management across the globe. An assessment of the literature is prepared on the state-of-the-art technologies in precious metals recovery from WEEE. The brief discussion of green technology approaches to acquiring precious metals from WEEE is reviewed. This review gives an approach for selective recovery of metal using DES, which suggests that the DES can be re-utilized after the extraction of metals.