From waste to energy

In Fuel Cells, Some Hope for Urban Sanitation

By SOPHIA LI

As more and more people around the world flock to cities, urban areas in developing nations are struggling to keep up with the human influx and the waste that people produce. In 2010 roughly 2.5 billion people lacked basic sanitation, according to the World Health Organization.

Energy Environ. Sci., 2012Microbes on the anodes (shown in green) break down the organic material in wastewater, producing carbon dioxide, protons and electrons.

A team of engineers has developed a tool that may prove to be a solution: fuel cells that harness a mix of microbes to clean wastewater while producing their own power. The technology is young, but it shows promise, said Hong Liu, an associate professor of biological and ecological engineering at Oregon State University who heads the team. The researchers’ fuel cells generate more power from waste than other, similar fuel cells, according to a recent article in the journal Energy and Environmental Science. If scaled up, the technology would even outpace the digesters that many treatment plants currently use to extract energy from wastewater, Dr. Liu said./.../