VATIS UPDATE Article

A team of researchers at University of South Florida (USF), the United States, is working to use naturally-occurring fungi for an environment-friendly recycling process to extract cobalt and lithium from waste batteries. “The idea first came from a student who had experience extracting some metals from waste slag left over from smelting operations,” said Jeffrey A. Cunningham, at USF. Cunningham’s team is developing the environmentally-safe way to do this with organisms found in nature – fungi in this case – and putting them in an environment where they can do their work.

To drive the process, Cunningham and Valerie Harwood, both at USF, are used three strains of fungi – Aspergillus niger, Penicillium simplicissimum and Penicillium chrysogenum. The team first dismantled the batteries and pulverised the cathodes. Then, they exposed the remaining pulp to the fungus. “Fungi naturally generate organic acids, and the acids work to leach out the metals” added Cunningham. According to the results, using oxalic acid and citric acid, two of the organic acids generated by the fungi – up to 85 per cent of the lithium and up to 48 per cent of the cobalt – from the cathodes of spent batteries were extracted.