Many electronic devices, such as smartphones, computers, and televisions, contain small amounts of gold in components such as connectors, circuit boards, and integrated circuits, but they are often considered e-waste.
When these devices are finished, we dispose of them and the ** attached to these electronic devices goes with them. While they are **and valuable**, the methods used are energy-intensive and often require highly toxic chemicals.
As a result, the team led by Professor Mezzenga from ETH has discovered an efficient, affordable and very sustainable solution: they use the by-products of the cheese-making process to extract from e-waste**.
Whey protein is the liquid that remains after milk has curdled and filtered during cheese production. It contains protein, lactose, vitamins, and minerals.
The team used whey protein to make sponges, extracted from old computer motherboards dissolved in acid**. Due to the special structure of proteins, sponges work better than other metals by adhering to gold ions.
After absorbing **, it is turned into small pieces and melted into gold nuggets. Surprisingly, the team only got a gold nugget weighing 450mg and 91% pure gold from 20 motherboards.
The team believes their process can be used on a larger scale.
My favorite fact is that we are using by-products from the food industry to get from e-waste**, says Mezzenga. "It doesn't get much more sustainable than that!”
Their approach contributes to e-waste and food waste and creates value from these wastes in line with circular economy principles.
E-waste is becoming increasingly important, not only for environmental reasons, but also for valuable materials. It's a win-win situation, with less waste and valuable resources being sustained**.
Through processes such as mechanical shredding, chemical leaching, and smelting, traders can extract and refine e-waste and others for reuse, reducing the need to mine new resources and minimizing environmental impact.
The study was published in the journal Advanced Materials.