MrSeb writes: "Bioengineers at Oregon State University (OSU) have developed a microbial fuel cell that can treat waste water — and generate significant amounts of electricity at the same time. The microbial fuel cell (MFC) works much like a normal fuel cell, but it uses waste water as a fuel (instead of hydrogen or ethanol), and specially-crafted bacteria act as a catalyst (instead of platinum). In the case of this fuel cell, developed by Hong Liu and her OSU colleagues, waste water comes into the fuel cell (at the anode), and bacteria oxidizes the organic compounds, producing spare electrons that flow to the cathode — creating electricity. The anode and cathode are separated by a membrane that only clean water can pass through, purifying the waste water. All told, the MFC produces two kilowatts of power per cubic meter of bioreactor volume — not a huge amount, but apparently 10 to 50 times more power electricity than other MFCs on the market. Compare this MFC with conventional "activated sludge," which has been the standard method of treating water for almost 100 years. In the US alone, according to OSU, water treatment makes up 3% of the country's total power consumption."