Eco Factor: Sewage treatment plant to generate renewable energy.
Sewage treatment plants make use of a variety of bacterium that convert organic matter into methane but leave waste containing ammonium into phosphates, which is further removed before the water is poured into rivers.
Apart from certain bugs, the process requires energy at the rate of 44Wh per day for each person who adds waste to the sewage system. In a large city, this process can require many megawatts. Researchers at the Delft University of Technology have come up with a technique that cuts the energy-consuming process with one that doesn’t require oxygen and can directly convert ammonium into nitrogen gas.
The technique is based on the use of so-called anammox bacteria that breaks ammonium directly into nitrogen. The only by-product of the process is methane, which can he harvested as fuel. The team calculates that the process can generate up to 24Wh per person per day, which can make these plants completely sustainable.
Via: New Scientist
