Representative image of e-waste.
Cresi: iStock
Chennai: Researchers with the Indian Institute of Technology Madras (IIT-M) have developed an innovative, green, and sustainable method to recover valuable metals from electronic waste (e-waste) using environmentally-friendly solvents derived from natural compounds.
This breakthrough could pave the way for safer and more eco-efficient e-waste recycling practices that protect the environment while supporting India’s circular economy goals, the IIT-M said.
In their study, the team developed a green solvent from thymol (derived from thyme) and capric acid, which effectively dissolved copper metal. The dissolved copper was then safely extracted using trisodium citrate, a non-toxic chemical, and subsequently used to synthesise copper nanoparticles -- materials with significant industrial and technological applications.
By adjusting the pH of the solution, the researchers could produce different forms of copper, such as copper oxide nanoparticles and pure copper metal. The process was also successfully extended to recover iron from real e-waste samples like printed circuit boards and copper sheets.
E-waste, which is one of the fastest-growing waste streams globally, contains a wealth of recoverable metals such as copper, gold, and iron. But, conventional recycling methods rely on harsh chemicals that produce toxic effluents and often yield metals in impure forms requiring further processing.
The findings of the research, which was conducted by Prof. Ranjit Bauri, Department of Metallurgical and Materials Engineering, Prof. S. Pushpavanam, Department of Chemical Engineering; and Sinu Kurian, Ph.D, were published in The Journal of Sustainable Metallurgy, a reputed peer-reviewed journal that focuses on advancing the circular economy principle.
Elaborating on the unique aspects of this Research, Prof Pushpavanam said unlike conventional acid-based extraction techniques, this method is biodegradable, non-toxic, and water-efficient, generating no hazardous waste.
“It's ability to recover multiple metals and directly produce valuable nanomaterials makes it more versatile and sustainable than other existing approaches,” he added.
Prof Ranjit Bauri said the green recovery process can significantly reduce pollution and environmental damage caused by e-waste while minimizing the demand for virgin metal mining. “For society, the innovation promises safer recycling systems, cleaner ecosystems, and efficient use of natural resources, aligning with India’s sustainability and net-zero commitments,” added Prof Bauri.
IIT-M is also exploring collaborations with industry and recycling companies for pilot-scale implementation, with possibilities of technology transfer and licensing to enable real-world adoption.