Old milk can be used to extract gold and other metals from e-waste

An aerogel made from old milk can extract highly pure gold nuggets from discarded computer motherboards.

Discarded electronics, known as e-waste, often contain large amounts of gold and other heavy metals. Scientists have come up with methods to recover the valuable metals, but these processes often rely on synthetic chemicals that can damage the environment.

Raffaele Mezzenga at ETH Zurich in Switzerland and his colleagues have developed a way to recover gold from e-waste by using a milk-derived aerogel, a type of gel…