A team at the J. Craig Venter Institute is developing a dual purpose microbial fuel cell (MFC) that could use bacteria in city sewage to clean the water and produce electricity. The microbes break down organic matter in the water, producing electrons as they digest. The electrode in the MFC collects the electrons to be used as electricity. Protons from the sewage pass through a membrane to another container where the bacteria combine them with oxygen, creating compounds such as water and hydrogen peroxide.
Currently, the MFC can remove 97 percent of the organic matter in the sewage water, according to a lead researcher. However, 99.99 percent of the matter should be removed before the water can be consumed. Researchers are currently working toward a device that can be used in homes. Though the energy recovery capacity is currently at 13 percent, researchers say it could eventually be 100 percent energy efficient.
Read more at Eurekalert.