Electronic waste (e-waste) has emerged as one of the fastest-growing waste streams worldwide, posing severe environmental and health risks. In an exclusive interview with our correspondent, Dr Emmanuel Oke, a Nigerian based in South Africa and a postdoctoral research fellow at the School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, sheds light on the urgent need for innovative e-waste recycling technologies, particularly for discarded printed circuit boards (PCBs). With his extensive research in sustainable recovery of metals using organic acids, ionic liquids, and deep eutectic solvents, Dr Oke advocates for cutting-edge approaches that prioritise resource recovery while minimising environmental impact.
The Growing Challenge of E-Waste
According to Dr Oke, the rapid advancement of technology has exacerbated the e-waste crisis, with millions of tonnes of discarded electronics piling up each year. “The global volume of e-waste reached 53.6 million tonnes in 2019, marking a 21% increase since 2015, according to The Global E-waste Monitor. Unfortunately, only 17% of this was properly recycled, with the rest being either openly burned or disposed of illegally,” he explained. Dr Oke further highlighted that the situation has worsened in recent years. “In 2022, less than one-quarter, or just 22.3%, of the year’s e-waste mass was documented as having been properly collected and recycled. This left approximately 62 billion US dollars’ worth of recoverable natural resources unaccounted for, increasing pollution risks to communities worldwide,” he stated.
He warned that the global generation of e-waste is on the rise, increasing by an estimated 2.6 million tonnes annually. “If this trend continues, we are on track to reach 82 million tonnes of e-waste annually by 2030, which would be a 33% increase from the 2022 figure,” he noted. Africa is not exempt from this crisis. “In 2019, about 2.9 million tonnes of e-waste was generated across the continent. The highest e-waste generating countries were Nigeria, Egypt, and South Africa, which also happen to be major population centres,” Dr Oke explained. “This highlights the urgent need for stronger policies and sustainable recycling solutions in these regions.”
PCBs, essential components of electronic devices, contain a complex mix of metals such as copper, aluminium, iron, zinc, tin, scandium and precious elements like palladium, gold, silver and so on. “PCBs offer significant recycling potential due to their high metal content, yet improper disposal releases hazardous substances like lead, mercury, and cadmium among others, which pose serious environmental and health risks,” he further warned.
Traditional and Emerging Methods of Metal Recovery
Dr Oke explained that traditional metal recovery methods such as pyrometallurgy, which involves high-temperature smelting, and hydrometallurgy, which relies on inorganic acids, cyanide, and other toxic chemicals, are highly unsustainable due to their environmental impact and expensive nature. “These processes generate toxic emissions and hazardous waste, making them less viable for long-term sustainability,” he stated.
He highlighted that emerging techniques such as the use of deep eutectic solvents, ionic liquids, organic acids, and amino acids are revolutionising metal recovery. “These alternative solvents provide a greener, more selective, and efficient way to extract metals from e-waste without the environmental hazards associated with traditional methods,” he noted.
Recent Publications on E-waste Management and Research Grant
Dr Oke has recently published two significant research articles on e-waste management, both of which are attracting considerable attention from the scientific community. “These papers have been highly cited and have contributed to advancing knowledge in the field of sustainable metal recovery from e-waste,” he stated. His work has provided valuable insights into the efficient recovery of metals from PCBs and the role of advanced solvent systems in sustainable recycling.
In December 2024, Dr Oke was awarded a research grant of R900,000 by the Oppenheimer Memorial Trust for his research on the sustainable recovery of metals from printed circuit boards, the most metal-rich components of e-waste, using deep eutectic solvents. The Oppenheimer Memorial Trust is widely regarded as one of the most prestigious funding institutions on the African continent, supporting leading scholars with a sustained record of outstanding research and intellectual achievement at the highest level.
His two recent publications below can be consulted for more information on e-waste management:
1. Oke, E.A., Potgieter, H. Recent chemical methods for metals recovery from printed circuit boards: A review. Journal of Materials Cycles and Waste Management, 26, 1349–1368 (2024). https://doi.org/10.1007/s10163-024-01944-4.
2. Oke, E.A., Potgieter, H. Discarded e-waste/printed circuit boards: a review of their recent methods of disassembly, sorting and environmental implications. Journal of Materials Cycles and Waste Management, 26, 1277–1293 (2024). https://doi.org/10.1007/s10163-024-01917-7.
Environmental and Health Implications
The consequences of improper e-waste disposal are dire. “Toxic heavy metals and organic pollutants from discarded electronics contaminate soil, water, and air, leading to respiratory diseases, neurological disorders, and even cancer. Informal recycling, especially in developing countries, exposes workers and surrounding communities to these hazardous substances,” Dr Oke stressed.
He pointed out that open burning of PCBs releases dioxins and furans, while landfilling allows heavy metals to leach into groundwater. “This calls for immediate policy interventions, including stricter regulations on e-waste disposal and increased investment in sustainable recycling technologies.”
The Future of E-Waste Recycling
Looking ahead, Dr Oke envisions a future where e-waste is seen as a valuable resource rather than a burden. “We need a systemic shift towards a circular economy model where electronic products are designed for longevity, repair, and recycling. Advancements in artificial intelligence, robotics, and eco-friendly chemical treatments can transform the e-waste management industry.”
He also emphasised the role of policymakers and industry stakeholders in fostering sustainable solutions. “Stronger regulations, extended producer responsibility (EPR) programmes, and public awareness campaigns can drive the adoption of environmentally friendly recycling methods. Consumers also have a role to play by responsibly disposing of their electronic devices and supporting refurbished electronics.”
Dr Oke concluded with a call to action. “E-waste recycling should not be just about disposal. It should be about resource recovery, environmental protection, and long-term sustainability. The time to act is now if we are to secure a cleaner and healthier future.”
