From present to future: A review of e-waste recycling processes

The global acceleration of electronic waste (e-waste) generation has created significant environmental, economic, and social challenges. Emerging technologies and shorter product lifespans are expected to intensify this growth. Despite the potential for material recovery, only a small fraction of e-waste is formally recycled, with a significant loss of critical resources such as rare earth elements and increased environmental degradation. Although prior studies address specific economic or environmental dimensions of e-waste management, detailed evaluations of recycling technologies from all three sustainability pillars are limited. This paper uses a structured sustainability framework to review five major recycling processes, including physical disassembly, pyrolysis, hydrometallurgy, biometallurgical treatment, and supercritical fluid technology. Social implications include occupational health and safety risks, public health impacts, and socioeconomic disruptions associated with transitions from an informal to a formal system. The results show physical disassembly and hydrometallurgical methods are widely used, however, they create considerable health risks and require better environmental impact data. Biometallurgical approaches have lower environmental toxicity but are constrained by limited scalability and process efficiency. Pyrolysis provides partial energy recovery but generates concerns over pollutant emissions and worker safety. Supercritical fluid technologies have high technical promise, however, their economic and operational viability are underdeveloped. The paper proposes a roadmap for advancing e-waste recycling systems by identifying data gaps and technology-specific opportunities for sustainable scale-up.