A consortium of organisations is tackling the electronic waste problem using a new combined biological and chemical approach.
Valuable gold and copper can be extracted from printed circuit boards using recyclable solvents. Other metals – such as aluminium, tin, and zinc – can then be recovered separately from the resulting effluent using a ‘DRAM’ filtration system.
The consortium, comprising of Aberdeen-based environmental tech firm SEM; WEEE Scotland, Edinburgh Uni and the Industrial Biotechnology Innovation Centre (IBioIC) – said it has “proven the feasibility” of a more sustainable method for recovering reusable scrap metal from old electronics.
Traditional physical and chemical extraction techniques are currently use a lot of energy or solvents that are difficult to recycle to dissolve valuable metals from electronic circuit boards.
Additionally, the latter process generates large volumes of acidic liquid waste containing traces metals, which can be damaging to the environment.
Commenting on the DRAM process, Leigh Cassidy, lead scientist at SEM, said: “There are a number of methods for removing valuable metals from electronic waste, but they are largely chemical and physical which comes with an environmental cost.
“This project has proven the use of an approach that is more rooted in biology and, with that, is much more sustainable – each stage of the filtration process has a lower impact than if it was done in any traditional manner.
“We are now looking to build the system into WEEE’s operations and then take it to other sites, where processes can be made more environmentally friendly. The next stage will be commercialising the technology to full effect, and we are pulling together bids for funding to make that happen.”
Professor Jason Love from the University of Edinburgh, said: “This exciting project has allowed us to marry chemical processes that separate valuable and critical metals from electronic waste with a biological filtration method that both maximises the metals recovered and minimises the overall environmental footprint.
“According to the UN’s Global E-waste Monitor 2020 report, in 2019 the UK produced the second highest level of electrical waste per capita at 23.9 kilograms – a total 1.6 million tonnes of waste electronics. Most of this waste is transported to Asia for processing, which also contributes to the environmental impact of electronic waste.”
Love added that, once commercialised, the new filtration process could not only “reduce the reliance” on metal resource mining for electronics, but also “reveal the opportunity for Scotland and the UK to drive more circular practices and create value from ‘e-waste’.”
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Liz Fletcher, director of business engagement at IBioIC, added: “With demand for electronics only likely to increase, this project is an incredibly important step forward in the treatment and management of e-waste.
“The consortium has designed a new approach to recovering metals for re-use that is significantly more sustainable than anything that has been done so far, underlining what can be achieved through collaboration.
“There is a huge opportunity for Scotland, and the wider UK, to lead the way in creating value out of used electronics and other waste streams through biologically based, sustainable methods. These materials need to be recycled and doing so could make a significant contribution to supporting our bid to become a net-zero nation by 2045.”