| Electrifying sewage |
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Publication Date:26-May-2006 02:00 PM US Eastern Timezone Source: Ghent University |
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Wastewater from toilets could do more than go just down the drain. It
could become a new renewable source of electricity. Bacteria like those in
wastewater naturally produce electrons as they decompose organic material;
and electricity is nothing more than flowing electrons. There already are
microbial fuel cells (MFCs), which produce minute amounts of electric
current by exploiting electron-producing chemical reactions inside
bacteria.
The challenge is to make practical MFCs that produce enough electricity to power devices in the real world. A report scheduled for the May 15 issue of Environmental Science & Technology now provides researchers with reassurance that practical MFCs are possible. The study was done by Willy Verstraete and colleagues, of the Laboratory of Microbial Ecology and Technology at Ghent University in Belgium. Researchers had hoped to get higher voltage or more current by connecting multiple MFCs together, much like batteries stacked inside a flashlight. However, they faced uncertainties about how stacking MFCs might affect the electricity-producing microbial populations inside each fuel cell. Verstraete's research focused on how
stacking of MFCs and the evolution of the microbial communities inside the
MFCs influenced the electric output. "This is the first report that
relates the evolution of the electrochemical and microbial features of
MFCs," he noted. |