The project is aimed at enabling the recovery of rare earth elements such as lanthanum, neodymium and dysprosium, which are used in the manufacture of microchips. “They are only used in trace amounts, but when you consider how many chips there are, altogether it really is a lot,” explained Dominik Schild from the Department of Life Sciences at IMC Krems.
These rare earth elements are currently extracted through opencast mining. 80% of this takes place in China, as environmental regulation is less stringent than in Europe there. “What opencast mining leaves behind isn’t very pretty,” commented Dominik Schild. He also pointed out that ever larger areas of land will have to be dug up in order to increase output. The elements are not being recycled in economically significant amounts at the moment as recovery methods are not currently profitable enough.
New waste-free technology
“In preliminary studies with the Czech Academy of Sciences, we found that if you dissolve these elements in a liquid, they will be preferentially absorbed by certain organisms. Our Czech partners have mainly been working with various types of green algae, while we’ve been concentrating on extremophile microorganisms and co-cultures,” said Prof. Dana Mezricky from IMC Krems’ Institute of Biotechnology.
“The idea was to obtain the luminophores, which came in a powder form, and experiment with how the organisms work. The question was then to find out if it ended up on the exterior of cells or in the cells, and which organisms absorb it especially well, and under what conditions,” added project assistant Dr. Doris Ripper.
This has led to the development of a new system. Biotechnologists normally try to work with genuine monocultures and keep them extremely clean. However, this project is looking at multiple organisms which have specific characteristics and cooperate with each other. Dominik Schild explained the reasons for this: “In extreme environments, organisms can only survive in groups. For instance, one organism begins producing something when it obtains water, and this activates the next organism, and so on. In this way they can survive in environments where the temperature is 70°C in the shade and it only rains once a year.”
A low pH value is required to dissolve the luminophores. Normally the pH would need to be neutralised because organisms usually only grow at a neutral pH. But the organisms being used here can survive in low pH environments – although not on their own, only as a group.
“We’re recovering these rare earth elements biologically, the advantage being that you can even split them up a bit – I’m able to predict where and when they will surface. What’s left over is biomass, which is biodegradable,” continued Schild.
One project, four institutions
The Czech Academy of Sciences and IMC Krems are responsible for identifying and cultivating the organisms which can absorb the elements. Danube University Krems is splitting the organisms, while Karl Landsteiner University of Health Sciences is carrying out extensive work on analysis and identifying the microorganisms. The whole project is being funded by Interreg and is scheduled to last four years.
The project is also intended to benefit the region, which is why the team are collaborating with waste recycling companies. The aim is to ensure that companies will be able to use the resulting technology on a large scale. A particularly encouraging aspect is that the technology will be used for recycling and not just waste disposal.