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Researchers extract gold using food waste byproduct in groundbreaking method: 'You can't get much more sustainable than that'

"I think the possibility to scale up and make it commercially profitable [is] very high."

"I think the possibility to scale up and make it commercially profitable [is] very high."

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Scientists in Switzerland might have the Midas touch, at least when it comes to recovering gold from old motherboards.  

And unlike the fabled king whose bodily contact turned the objects around him into gold (even his food), there should only be upside to this scalable, successful process that pulls the precious metal from the vast amounts of e-waste we generate each year. 

What's more, the ETH Zurich team is using food scraps to accomplish the task, doubling down on the project's recycling potential. 

"You can't get much more sustainable than that," Professor Raffaele Mezzenga said in the Zurich lab report. 

The process is made possible by whey, a byproduct of the cheesemaking industry. It is used to help make a sponge, which collects the gold when the e-waste is soaked in an acid bath. It also uses high heat to melt the flakes of gold, forming a nugget. 

The value can be immense. The team gathered enough gold to form a 22-carat nugget, weighing 450 milligrams. And Reuters reported that the gold market is up, hitting a record peak at $2,276.89 per ounce, as of April 2. The precious metal was harvested from 20 old motherboards. 

Better yet, the gold that was gathered by way of cheese sponge is 50 times more valuable than the cost of the process to secure it. 

"I think the possibility to scale up and make it commercially profitable [is] very high," Mezzenga said in a story on the research from Anthropocene. "And indeed, we are working on it."

The experts say this technique is a big improvement over current ones that require toxic chemicals, per the Zurich lab report. 

Globally, data collector Statista notes that we produce more than 55 million tons of e-waste, from smartphones, computers, and other technology each year.

Efforts to recycle the rare and hard-to-harvest metals that partially form the equipment can make the electronics sector more sustainable — it could even make devices more affordable for consumers. 

Another project rolled out to better handle e-waste, or prevent it altogether, includes a dissolvable circuit board from London's Jiva Materials

For Mezzenga, finding a productive use for food scraps is a bonus for the Zurich breakthrough. Better using the waste can prevent it from ending up in landfills, where it makes potent planet-warming methane. An overheating planet, in turn, can impact our food system itself, disrupting farm labor productivity during growingly common heat waves. 

The creation of gold nuggets is a bonus for the Zurich crew. 

"The fact I love the most is that we're using a food industry byproduct to obtain gold from electronic waste," Mezzenga said in the lab summary.

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