A pioneering research project to clean up a flooded English tin mine uses algae to extract heavy metals from its toxic water while simultaneously producing biofuel. The project is at a very early stage but if successful it could have environmental benefits worldwide.
The GW4 Alliance, which brings together the universities of Bath, Bristol, Cardiff and Exeter, in collaboration with Plymouth Marine Laboratory (PML), the Coal Authority and waste management group Veolia, is growing algae in untreated mine water samples from the Wheal Jane tin mine in Cornwall, England.
The Wheal Jane tin mine is center of a research project to use algae to remove harmful waste products from toxic mine sites while producing biofuels simultaneously. Credit: GW4.
The researchers hope that the algae is effective in removing harmful materials, such as arsenic and cadmium, from the mine water. They plan to convert the algae into a solid from which heavy metals can be extracted and recycled for use in the electronics industry. The remaining solid waste will then be used to make biofuels.
“It’s a win-win solution to a significant environmental problem,” said Dr Chris Chuck from the University of Bath’s Centre for Sustainable Chemical Technologies. “We’re putting contaminated water in and taking out valuable metals, clean water and producing fuel.”
The Wheal Jane mine closed in 1992. The British Department for Environment, Food & Rural Affairs still spends £2m a year combating its polluting effects on the local environment.
Dead algae has long been used to filter water but the Wheal Jane project uses live algae found at the site to “remediate” its toxic water.
If successful, the researchers believe the process could be used to treat many forms of environmental pollution. The team has just received funding to perform similar studies in Vietnam, where it will examine whether algae can be used to treat additional industrial waste bi-products.
“Acidic waste run-off from mines is not a regional issue restricted to Cornwall, it’s a global problem,” said Dr. Mike Allen, director of the Algal Biotechnology and Innovation Centre at PML. “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.”
While the work so far has taken place in a laboratory setting, the team plans to begin a pilot project at the mine site later this year.