Recycling for remediation: Catalytic potential of e-waste and mining byproducts in water treatment

Abstract

: Water pollution remains a significant global issue, with traditional treatment methods often being costly, energy-consuming, and less effective against emerging contaminants. Recycling waste streams, such as electronic waste (e-waste), mining byproducts, and other industrial residues, offers a promising alternative by serving as valuable precursors for catalysts in water treatment. This review highlights recent advances in the development of waste-derived catalysts and their role in sustainable remediation. We begin by examining the chemical diversity of waste streams, including metals, oxides, and composites from e-waste, as well as tailings and slags from mining. Their diverse compositions make them ideal feedstocks for catalyst synthesis via physical, chemical, and environmentally friendly methods. Techniques such as surface modification, doping, and hybridization further enhance catalytic performance. The review then discusses catalytic mechanisms pertinent to wastewater treatment, such as advanced oxidation processes (AOPs), photocatalysis, electrocatalysis, and adsorption-based reactions, which effectively degrade dyes, pharmaceuticals, heavy metals, and other pollutants. Case studies illustrate the successful application of waste-derived catalysts for the degradation of organic pollutants and the detoxification of heavy metals, and compare their performance with that of commercial catalysts in real wastewater scenarios. Besides water remediation, these catalysts have potential in broader areas like hydrogen production, CO 2 reduction, and air quality improvement, supporting integrated energy-environment-water solutions. The review also considers environmental and socioeconomic factors, including life-cycle analysis, leaching risks, and opportunities for the circular economy. Despite challenges related to techno-economic viability and scalability, advancements in nanotechnology, AI-driven material design, and supportive policies could boost adoption. This review emphasizes the potential of recycling waste into catalysts as a sustainable pathway for water treatment, highlighting key obstacles, knowledge gaps, and future trends toward large-scale, eco-friendly, and affordable remediation solutions.