IISER Pune team develops hybrid aerogel to extract gold from e-waste

India’s electronic waste generation has been rising exponentially in recent years, even though its global share is just 6.4 per cent.

But e-waste, which spans everything from electronics, gadgets, computers, contains metals like gold, copper, silver. It is thus necessary to find sustainable ways to extract these resources from waste.

Between 2020 and 2022, the e-waste generation grew by 131 per cent, according to UN Trade and Development report.

The global e-waste monitor 2020 report has projected an increase of e-waste from 9.2 million tons to 74.7 million tonnes by the end of this decade in India.

Sujit Ghosh and team at IISER, Pune, have designed and synthesised aerogel : the sponge-like absorbents, light in weight and porous synthetic materials for this purpose. Aerogels are most preferred in environment and oil spill clean up, for insulation purposes and more.

The aerogel’s unique structural composition was treated with iron nitrate salts and maintained at room temperature for about two to five minutes. This specially designed aerogel was found to be effective in extracting and retrieving upto 99 per cent of gold ions from the e-waste.

In daylight, the hybrid aerogel could extract 1689mg/gram of e-waste and 2349mg / gram under blue light.

As there were dual processes involved, that of adsorption and reduction — the quality of the recovered gold was reasonably pure thereby reducing the need for further purifying processes.