Penn State environmental engineers have shown, for the first time, that a microbial fuel cell (MFC) can generate electricity while simultaneously cleaning the wastewater that you flush down the drain or toilet.

Microbial fuel cells work through the action of bacteria which can pass electrons to an anode, the negative electrode of a fuel cell. The electrons flow from the anode through a wire, producing a current, to a cathode, the positive electrode of a fuel cell, where they combine with hydrogen ions (protons) and oxygen to form water.

No special bacteria are added. The naturally occurring bacteria in wastewater drive power production via a reaction that allows them to transport electrons from the cell surface to the anode. In addition, a reaction (oxidation) that occurs in the interior of the bacterial cell lowers the biochemical oxygen demand, cleaning the water.

The single-chambered microbial fuel cell is essentially a Plexiglass cylinder about the size of a soda bottle. It contains eight anodes, composed of graphite, that supply about 36 square inches of surface area to which the bacteria can adhere and pass electrons. The cathode is a carbon/platinum catalyst/proton exchange membrane fused to a plastic support tube. >from *Microbial Fuel Cell Cleans, Generates Electricity From Domestic Wastewater. February 23, 2004

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> how do we clean our wastewater ?