A new research project could help clean up old mining messes by turning waste water into a useful resource
A scientific research project is using algae to extract biofuel and precious metals from toxic water in abandoned mines, while simultaneously restoring the ecological health of the area.
Scientists from Bath, Bristol, Cardiff and Exeter universities have joined forces on the project, known as the GW4 Alliance, and have begun experimenting with waste water from a deserted tin mine in Cornwall.
Algae is cultivated within the water to remove harmful elements, such as arsenic and cadmium – some of which can be recycled back into the electronics industry – with the remaining waste transformed into biofuel and fertiliser.
Conservationists and campaigners alike have long known the ecological devastation wrought by mining activity. The waste water left behind can stretch over a vast area and often contains potentially harmful chemicals, including sulphuric acid and mercury. This threatens the contamination of surface and ground water, occasionally poisoning domestic sources and threatening the existence of local wildlife.
The production of biofuel from algae currently carries a high price tag, but could be potentially profitable in the long-term. Dr Mike Allen from the Plymouth Marine Laboratory said: “If we can make the numbers work so that we outweigh the cost of clean-up by the production of metal and biofuel, that’s when this local solution can go global.”
One hurdle is how the technique can be scaled up. For this reason, scientists remain cautious about the technology, but researchers are hopeful for progress. Dr Chris Chuck from Bath University said: “We are now applying the technology to other types of waste water and even contaminated industrial effluent.”