Microbial Fuel Cell Research Shows Promise

Environmental engineers at Penn State have shown for the first time that electricity can be generated from wastewater by microbial fuel cells (MFCs) while simultaneously removing pollutants.

Other researchers have shown that MFCs can be used to produce electricity from water containing pure chemicals including glucose, acetate or lactate. The Penn State researchers led by professor Bruce Logan are the only ones, so far, to show that MFCs can produce electricity directly from wastewater skimmed from the settling pond of a treatment plant. To date, the experiments have produced between 10 and 50 milliWatts of power per square meter of electrode surface. This amounts to about 5 percent of the amount of energy needed to run one mini-Christmas tree light, while removing up to 78 percent of organic matter as measured by biochemical oxygen demand (BOD). The fuel cells work by using bacteria to help conduct electricity. The oxidation reaction that occurs inside the bacterial cell in turn lowers the BOD, cleaning the water. The technology is still experimental, but the researchers are optimistic that MFCs may someday be able to help reduce the cost of wastewater treatment around the world. For more information, visit http://www.psu.edu/ur/2004/microbfuel.html.