WASHINGTON, Dec. 3 (Xinhua) -- U.S. Scientists developed a fuel cell that uses pollution from coal and metal mines to generate electricity, solving a serious environmental problem while providing a new source of energy.

Researchers from The Pennsylvania State University describe successful tests of a laboratory-scale version of the device in their papers published Monday in the December issue of Environmental Science & Technology, a publication by American Chemical Society.

In the new study, Bruce Logan and colleagues point out that so-called acid-mine drainage (AMD) is a serious environmental problem that threatens the health of plants and animals as well as the safety of drinking-water supplies, due mainly to the high acidity of contaminated waters and its high content of metals, particularly iron. AMD poses difficult and costly environmental clean-up problems.

They devised a new type of fuel cell that is based on microbialfuel cells, which are capable of generating electricity from wastewater. Using a solution similar to AMD, they showed that the device efficiently removed dissolved iron from the solution while also generating electricity at power levels similar to conventional microbial fuel cells.

Improvements in the fuel cell will lead to more efficient power generation in the future, the researchers say. The iron recovered by the device can be used as a pigment for paints or other products, they note.