Engineering news
Researchers in the UK are developing a mining process that uses algae to extract precious metals and produce biofuel and clean water from a disused mine in Cornwall.
The researchers at Bath, Bristol, Exeter, Cardiff and Plymouth Universities are growing algae in untreated mine water samples taken from the Wheal Jane tin mine in Cornwall. The experiments aim to develop an algae-based process to remove poisonous materials such as arsenic and cadmium from the mine water.
The researchers will then develop a process to convert the algae into a solid form, so that precious heavy metals can be extracted and used in the electronics industry. The remaining solid waste will then be used to make biofuels.
Dr Chris Chuck, from the University of Bath’s Centre for Sustainable Chemical Technologies, said: “It’s a win-win solution to a significant environmental problem. We’re putting contaminated water in and taking out valuable metals, clean water and producing fuel.
“This technology could be applied to any type of mine or could even be used to clean up industrial effluent in the future.”
The Wheal Jane tin mine, near Truro in Cornwall, closed in 1992, but the remaining water in the disused mine has caused significant pollution, contaminating the groundwater and killing nearby wildlife. A plant that pumps out and stores contaminated water from the mine costs around £1.5 million to operate annually. Total costs for the clean-up are thought to run into the tens of millions.
Dr Mike Allen, director of The Algal Biotechnology and Innovation Centre at the Plymouth Marine Laboratory, said: "Acidic waste run off from mines is not a regional issue restricted to Cornwall, it's a global problem. It's a particular problem in the developing world where costly clean-up and remediation activities are ignored because of their high cost and low return.
“By making the clean-up process pay for itself, we can improve both the health and the environment of millions of people around the world."
The research is being led by the GW4 Alliance, a consortium of South West English and Welsh universities in collaboration with the Plymouth Marine Laboratory (PML), the Coal Authority and Veolia.