Recent sustainable trends for e-waste bioleaching

Abstract

For the past few decades, the electronic and electrical waste have been accumulating and piling on our lands and aside from posing some serious threat on our environment and our health. And with the technological advance and the rapid growing electronic demand and production there is the risk of accumulating even more unused valuable usable materials in our waste land-fields. Up to 2030, EU is forecasting about 74 million tons of e-waste, including washing machines, tablet computers, toasters, and cell phones. In 2022, more than 5.3 billion mobile phones were wasted whereas Li, Mn, Cu, Ni, and various rare-earth elements (like Nd, Eu and Tb, etc.) as well as graphite are actually found in the contents of many metal parts from wiring, batteries to their components. The main purpose aside from an environmental aspect is reserving the mineral used in this waste, as many of the crucial materials have a supply risk heavily depending on import. For instance, many of these rare earth elements (REE) are sourced from China; these REEs are used in many electronics that range from consumer products to industrial-use machines. This study is to review one of the desired methods that is via using bio-techniques to dissolve and recover as much as possible from main e-waste sources such as PCBs, spend batteries and LCD/LED panels. Microorganisms that are used for bioleaching process and their metal recovery aspects were compared in the second part. Future perspectives were finally added considering significant techno-economic environmental and social impacts.