The GW4 Alliance, comprising UK-based institutions the University of Exeter, University of Bath, University of Bristol and Cardiff University, in December announced a research project that will investigate the possibility of using algae to extract precious heavy metals from mine water, while simultaneously producing biofuel.

Researchers from all four universities, in collaboration with Plymouth Marine Laboratory (PML) are now working with the UK Coal Authority and water treatment solutions provider Veolia to take untreated mine water samples from the disused Wheal Jane tin mine, in Cornwall, the UK, to a laboratory where algae will be grown in the samples.

The research will explore whether algae is effective in removing materials such as arsenic and cadmium from the mine water.

The researchers will then look to convert the algae into a solid, from which it is expected that precious heavy metals can be extracted and recycled for use in the electronics industry. The remaining solid waste will then be used to make biofuel.

University of Exeter Environment and Sustainability Institute and Camborne School of Mines, sustainable mining and minerals resourcing lecturer Dr Chris Bryan, says: “By growing algae in mine water, which is currently expensive to remediate, we are providing an alternative economic model to traditional algal cultivation. The aim is to reduce the treatment costs, while [also] generating value from the algal biomass.”

“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,” University of Bath Centre for Sustainable Chemical Technologies Whorrod research fellow Dr Chris Chuck adds.

Meanwhile, PML Algal Biotechnology and Innovation Centre director Dr Mike Allen points out that acidic waste runoff from mines is not a regional issue restricted to Cornwall, but rather 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,” he states.

The Wheal Jane tin mine closed in 1992. The Department of Environment, Food and Rural Affairs has since 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.