First, the dark beer-colored sewage is pulled through a series of tubes stuffed with thousands of fibers pierced with holes 1/300th the size of a human hair. Anything larger than 0.2 millionth of a meter - which includes suspended solids and bacteria - is left behind. The cleansed water is then forced at high pressure through hundreds of tubes that are filled with tightly wound plastic membranes. Reverse osmosis, as the process is called, stops nonwater molecules - including viruses and pharmaceuticals.
Scientists from Stanford University have developed a microbial battery using 'wired microbes' to create power from sewage and wastewater. The technology, though small in scale, shows early promise as both an electricity source and an exciting new treatment for wastewater.