GW4 is the southwest research alliance that brings together four leading, research-intensive universities from Wales and Britain’s southwest: Bath, Bristol, Cardiff and Exeter.

PML, in collaboration with researchers from all four universities, is now working with the Coal Authority and Veolia to take untreated mine water samples from Wheal Jane tin mine in Cornwall into the laboratory and grow algae in them. The research will explore whether algae is effective in removing materials such as arsenic and cadmium from the mine water.
Researchers will then look to convert the algae into a solid from which precious heavy metals will be extracted and recycled for use in the electronics industry. The remaining solid waste will then be used to make biofuels.

The Wheal Jane tin mine, near Truro in Cornwall, closed in 1992. The Department of Environment, Food and Rural Affairs (Defra) has since that time funded the active mine water treatment scheme to protect the River Fal from pollution. This scheme is managed by the Coal Authority and operated by Veolia.

Dr Chris Chuck, Whorrod Research Fellow 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.”

Acid mine drainage is a global problem, particularly in the developing world where costly clean-up and remediation activities are sometimes ignored because of their high cost and low return. Growing algae in the mine water provides a revenue stream to offset the cost of remediation and could significantly reduce treatment costs.