A Comprehensive Review on Sustainable Metal Recovery from E-Waste Based on Physiochemical and Biotechnological Methods

Abstract

Numerous studies have concentrated on the recovery of valuable metals from waste printed circuit boards (WPCBs) in recent years. In this review study, metal recovery based on various physiochemical and biotechnological methods is reviewed majorly classified into five techniques: (i) physical recycling techniques, (ii) thermo-chemical techniques, (iii) pyrometallurgical method, (iv) hydrometallurgical method, and (v) bio-metallurgical method. Beneficially, these techniques favor the reusing of valuable metals from e-waste. It is found that some of the techniques such as pyrometallurgy and hydrometallurgy have been used traditionally which requires high cost and also has some harmful effects on the environment. In order to obtain socioeconomic and eco-friendly methods, the development of bioleaching using various microorganisms emerged in the field of biotechnology precedes the way to recover heavy metals. Based on the literature review, some of the important and experimentally proven techniques analyzed over years have been stated in this study. The significance of recovering metals from e-waste and their applications in various fields were also discussed.