Biobased Strategies for E-Waste Metal Recovery: A Critical Overview of Recent Advances

The increasing e-waste volumes represent a great challenge in the current waste management landscape, primarily due to the massive production and turnover of electronic devices and the complexity of their components and constituents. Traditional strategies for e-waste treatment focus on metal recovery through costly, energetically intensive, and environmentally hazardous processes, such as pyrometallurgical and hydrometallurgical approaches, often neglecting other e-waste constituents. As efforts are directed towards creating a more sustainable and circular economic model, biobased alternative approaches to these traditional techniques have been increasingly investigated. This critical review focuses on recent advances towards sustainable e-waste treatment, exclusively considering studies using e-waste sources. It addresses, from a critical perspective, approaches using inactive biomass, live biomass, and biogenic compounds, showcasing the diversity of strategies and discussing reaction parameters, advantages and disadvantages, challenges, and potential for valorization of generated by-products. While ongoing research focuses on optimizing operational times and metal recovery efficiencies, bioprocessing approaches still offer significant potential for metal recovery from e-waste. These approaches include lower environmental impact by reducing energy consumption and effluent treatments and the ability to recover metals from complex e-waste streams, paving the way for a more circular economy in the electronics industry.