01.09.2024

Bacteria help extract rare metals from old batteries

Scientists have found an unusual new ally in the fight against climate change. They use bacteria to help them extract rare metals that are vital to the development of green technologies, reports Guardian.

"Without the help of these microbes, we could run out of raw materials to build turbines, electric cars and solar panels," say the experts.

The work is led by scientists at the University of Edinburgh and aims to use bacteria that can extract lithium, cobalt, manganese and other minerals from old batteries and discarded electronic equipment.

“These scarce and expensive metals are vital to the production of electric cars and other devices on which green technology devices depend. If we are to end our dependence on petrochemicals and rely on electricity for our heating, transportation and power, then we will become increasingly dependent on metals. Photovoltaics, drones, 3D printing machines, hydrogen fuel cells, wind turbines and electric car engines all require metals, many of which are rare and key to their operations," emphasizes Professor Louise Horsfall, Chair of Sustainable Biotechnology at Edinburgh.

China dominates the market

Politics is also a problem, scientists warn. China controls not only the main supply of rare earth elements, but also dominates their processing.

“To overcome these problems, we need to develop a circular economy where we reuse these minerals whenever possible, otherwise we will run out of materials very quickly. There is only a limited amount of these metals on Earth and we can no longer afford to throw them away as waste as we do now. We need new recycling technologies if we want to do something about global warming," says Horsfall.

And the key to this recycling turns out to be bacteria.

"Bacteria are wonderful, crazy little creatures that can perform some weird and wonderful processes. For example, some bacteria can synthesize nanoparticles from metals. We believe they do this as a detoxification process. Basically, they latch on to metal atoms and then spit them out as nanoparticles so they don't get poisoned by them," explains Horsfall.

The strains are naturally occurring

Using such strains of bacteria, she and her team have already taken waste from electronic batteries and cars, dissolved it, and then used bacteria to latch on to certain metals in the waste and deposit them as solid chemicals.

"We did it first with manganese. Later we did it with nickel and lithium. And then we used a different strain of bacteria and we were able to extract cobalt and nickel," says Horsfall.

Most importantly, the strains of bacteria used to extract these metals are naturally occurring. In the future, scientists plan to use gene-edited versions to increase metal production.

"For example, we need to be able to extract cobalt and nickel separately, which we can't do at the moment," explains Horsfall.

The next part of the process will be to prove that these metals, once removed from old e-waste, can then be used as components of new batteries or devices.

"Then we will know if we are helping to develop a circular economy for working with green technologies. The new legislation stipulates that by the next decade, recycled metals will have to be used at significant levels for the production of new environmentally friendly technological devices. These goals will be difficult to achieve and bacteria will be vital to achieving them," concludes Horsfall.