Two waste streams, one valuable resource
As electronics consumption keeps surging, e-waste has become one of the biggest environmental challenges of the modern era. Old smartphones, computers and motherboards pile up in landfills — and when discarded, we lose precious resources and cause serious environmental harm.
But what if the path to a solution lay in the unlikeliest place — the dairy industry? Researchers at ETH Zurich, led by Prof. Raffaele Mezzenga, turned modern alchemy into a sustainable reality: a highly efficient method to extract pure gold from old computer motherboards, using a sponge made from protein fibers derived from cheese whey — a by-product of the cheese industry.
How it works
The magic is in a clever process: the researchers turn whey proteins into gel-like nano-fibrils, then dry them into a protein sponge. When the metal parts of the e-waste are dissolved in an acidic solution, the sponge acts like a selective magnet — gold ions cling to the protein fibers with exceptional efficiency compared with other metals.
The sponge is then heated, causing the gold ions to reduce into small flakes that can be melted into a pure gold nugget. In their experiment, the team recovered a 22-karat gold nugget from just 20 old motherboards.
Why it is a game-changer
Double sustainability: the process combines two kinds of waste — food-industry waste (whey) and electronic waste — and turns them into a valuable resource. As Prof. Mezzenga puts it, you cannot be much more sustainable than that.
Economical and efficient: unlike traditional recycling that demands huge amounts of energy and toxic chemicals, the new method is far cheaper — the production cost of the sponge and the process is about 50 times lower than the value of the gold ultimately recovered.
A clean solution: it reduces dependence on polluting mining and gives existing resources a new life.
The Green Solutions view
We believe this innovation is not just a scientific achievement but a glimpse into the future of the circular economy. The more we adopt technologies based on smart recycling and efficient resource use, the cleaner and richer our world becomes.
At Green Solutions we specialize in spotting breakthrough circular-economy technologies and mapping economic opportunities in waste and precious metals.
Key Benefits
- Gold from e-waste
- Whey-protein nano-sponge
- 22-karat nugget from 20 boards
- 50× cheaper than the gold value
- Double-waste circular solution
Want to Learn More?
Leave your details and we'll get back to you shortly.