“They hope their technique could be used in wastewater treatment facilities and to break down organic pollutants in the ‘dead zones’ of oceans and lakes where fertilizer runoff has depleted oxygen, suffocating marine life. However, for now the team from Stanford University have started small, with a prototype about the size of a D-cell battery, consisting of two electrodes — one positive and one negative — plunged into a bottle of wastewater, filled with bacteria. As the bacteria consume the organic material, the microbes cluster around the negative electrode, throwing off electrons, which are captured in turn by the positive electrode.”
http://www.rawstory.com/rs/2013/09/16/researchers-create-battery-that-recycles-sewage-into-energy/
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