Giving Waste Water the Power to Clean Itself
A technique that combines two novel forms of renewable energy — one relying on bacteria and the other on salt water — generates more electricity than either one alone and cleans waste water at the same time. The work was published recently in the journal Science.
Waste water contains a great deal of energy in the form of organic matter, said Bruce Logan, director of the Hydrogen Energy Center and the Engineering Energy and Environment Institute at Pennsylvania State University and lead author of the study. Domestic waste water contains nine times more chemical energy than the energy required to treat it — that amount, added to the energy in waste water from livestock and food production, would be nearly enough energy to maintain the entire US water infrastructure, he said.