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Estonian scientists are using microorganisms to extract metals from toxic waste.
Your smartphone is precious, but more so than you might expect. It has gold and silver hidden in its circuit boards in addition to many other important metals like cobalt, lithium and copper.
You could collect about a gram of gold from 35 smartphones. The quality is the same as that dug from the ground. Still, humans throw away most of their used electronic devices and reach for a new one without thinking about it.
Worldwide, only about 17.4 per cent of e-waste is appropriately collected and recycled, according to The Global E-waste Monitor.
It’s not just about throwing away the bling, however. Europe is running low on metals. Renewable energy solutions require a long list of metals, many of which are not in Europe. The EU has listed 30 critically low metals.
The batteries of green technology all consist of precious metals that help them last longer and run smoother.
There is another side to this coin too. The current industry processing minerals create a lot of polluting waste. If not properly recycled, the waste materials containing these valuable metals can also be toxic and leak harmful elements such as heavy metals and radionuclides into the environment.
Sadly, Europeans send many of their used electronic appliances to Africa. Out of sight, out of mind.
The good news is that all this “rubbish” actually contains all these valuable metals that we need.
Dependence on China
Estonian researchers have worked for the past 13 years to figure out how to safely and effectively get the metals out of the residue. They use microorganisms like bacteria, fungi, and archaea that react with metals, allowing them to solubilize in water.
The microorganisms separate metals from other substances. This process is called either biomining or bioleaching. In their reactor, the scientists experiment with various living organisms they develop or buy from biobanks. They can get gold out of a smartphone circuit board within days.
Most of Biotatec’s work occurs outside the lab, creating tailor-made solutions for the industry. BiotaTec‘s Chief Scientific Officer Priit Jõers cannot reveal their clients. “The interest from the industry is enormous,” he suggests. “Everybody is starting to realize that we need changes.” In some countries, solutions are needed fast.
Greece, with its massive aluminum production, creates a lot of red mud, formally known as bauxite residue. Aluminum is commonly used in power lines, household appliances, consumer electronics, aircraft components, electric cars, and modern buildings. Our lives couldn’t continue the same way without aluminum.
To produce one tonne of alumina, 0.8 tonnes of bauxite residue is created. “In Greece, there are serious problems already. There’s no land anymore to pile the waste,” Jõers said. This has many valuable metals and could be reused. With biomining, pollutants can also be removed, making it possible to dump the red mud safely.
Similarly, Poland struggles with phosphogypsum waste, a leftover from creating phosphorus. It can contain significant amounts of rare earths but also toxic metals and radionuclides.
Jõers explains that processing waste is not just environmentally responsible; it’s also geopolitically important: “Most of the essential metals we need for green energy come from Russia, China and South Africa. Europe needs resources too.“ Russia has already threatened to limit the exports of critical metals such as palladium and nickel.
We don’t need Russia or China to get all those valuable metals, Jõers believes. They already exist – in our piles of rubbish.
The European Union has understood the problem at the highest level. The EU expects its demand for rare metals to increase fivefold by 2030. Speaking at the Tallinn Digital Summit last October, Ursula von der Leyen said the EU must avoid dependency on China. Almost 90% of rare earths and 60% of lithium is processed in China, the country dominating the market.
Biomining has been around for decades, but it is only now becoming cost-effective. At the same time, mining as we know it is becoming wasteful and expensive.
Jõers: “Our solution does two things: we clean the waste so that it can be taken to the dumping ground. Secondly, we take out valuable metals that can be sold.”
Even if the users can’t tell the difference, in the coming years, it will be common to have biomined metals in new green technology, and even in smartphones.
Written by: Marian Männi. This article was funded by the European Regional Development Fund through Estonian Research Council.
