As renewable energy sources go, solar rays have historically hogged the limelight.
But two Virginia Tech researchers have stolen the spotlight from the sun by discovering a way to maximize the amount of electricity that can be generated from the wastewater we flush down the toilet.
Xueyang Feng and Jason He traced bacteria, which led them to discover that the working relationship between two specific substrates produced more energy than either did separately. This work will help take the mystery out of how electrochemically-active bacteria create energy. It could help in the development of new treatment system called a microbial fuel cell.
“Tracing the bacteria gave us a major piece of the puzzle to start generating electricity in a sustainable way,” said Feng, an assistant professor of biological systems engineering. “This is a step toward the growing trend to make wastewater treatment centers self-sustaining in the energy they use.”
Feng is in the College of Agriculture and Life Sciences and the College of Engineering; He, an associate professor of environmental engineering, is in the College of Engineering.
The discovery is important because not all organics perform the same job in the same way. Some work because they are food for the electricity-generating bacteria while others are good at conducting energy.
The team found that when these two substrates are combined, the output of energy is far greater than when they are working separately. The organics work in tandem with receptors in fuel cells, and while research using microbial fuel cells is not new, the kind of organics that Feng and He used was novel in generating electricity because they were able to measure the symbiotic nature of two particular organics.