Clever compost: Organic materials could help recycle electronic waste

Some organic materials could help to extract rare earth metals from electronic waste. — AFP Relaxnews

What if certain organic materials could help salvage rare metals– essential for the manufacturing of many digital devices – from waste electronics? This idea is being investigated and tested by a team of US researchers. Here’s how it works.

Neodymium may be a strange-sounding chemical element that you've never really heard of. Yet it is found in many of our everyday electronics, from computers to television screens to the engines of hybrid cars.

The problem is that, like most of the metals used to make our day-to-day devices, these are extracted from rare and non-renewable resources. Not to mention that the devices in question generally have a limited lifespan.

However, a method developed by a team of US scientists from Penn State University could kill two birds with one stone. Their technique involves using organic matter to help salvage these metals from waste.

More specifically, the researchers ground up tomato peel and corn cob, and then cut wood pulp and cotton paper into small pieces, before soaking them in water. These materials were then chemically reacted to split them into microproducts, nanoparticles and solubilized biopolymers. The microproducts and nanoparticles were then used to activate the separation process necessary to capture neodymium samples from neodymium solutions.

If this method was deployed on a large scale, the researchers believe it could both reduce the mass of electronic waste while limiting the mining required to obtain the rare earth elements found in many devices.

"In the near future, we want to test our process on realistic industrial samples," says Amir Sheikhi, assistant professor of chemical engineering and corresponding author of the research. His team also hopes to extend this technique to other precious metals, such as gold and silver.

According to a study commissioned by the Greens/EFA group in the European Parliament, published in December 2021, 40% of the digital environmental footprint in Europe is due to the depletion of metal resources and the use of fossil resources needed to manufacture electronic devices. – AFP Relaxnews