Fuel Cells/Microbe 040517

 (April 2004) Penn State engineers demonstrate that a microbial fuel cell (MFC) can generate electricity while simultaneously cleaning wastewater.  To date, the experiments with the cell have shown it to produce between 10 and 50 milliWatts  per sq. meter of electrode surface while removing up to 78 percent of organic matter as measured by BOD (biochemical oxygen demand). Dr. Bruce E. Logan, director of the project, says “MFCs may represent a completely new approach to wastewater treatment. If power generation of these systems can be increased, MFC technology may provide a new method to offset wastewater treatment plant operating costs.”

Microbial fuel cells work through the action of bacteria which can pass electrons to an anode.  The electrons flow from the anode through a wire, producing a current, to a cathode where they combine with hydrogen ions (protons) and oxygen to form water.   
(Sept. 2003) Ernst Moritz Arndt University in Greifswald, Germany create a prototype microbial fuel cell that utilizes energy from Escherichia coli as it feeds on sugar.  Hydrogen, and suspected bacteria feeding electrons directly onto the anode, are responsible for the output of energy.   The platinum anode with a conducing polymer slows down contamination, which has been a problem in previous research. The prototype can make up to 150 miliAmps which is enough to drive a medical ventilator.

To reference this information, see the following article:
Schröder, U., Nießen, J & Scholtz F., “A generation of microbial fuel cells with current outputs boosted by more than one order of magnitude, Angewandte Chemie International Edition, 42 2880-2883, (2003)