Steven Van Ginkel, doctoral candidate, and Dr. Sang-Eun Oh, post-doctoral researcher in environmental engineering, conducted the tests.
"In addition to hydrogen, which can be used as a fuel and industrial feedstock, methane, the main component of natural gas, can be generated from the wastewaters," says Van Ginkel. Both hydrogen and methane can be converted into electricity via fuel cells at close to 80% efficiency. "By extracting hydrogen and methane from their wastewaters, these plants can also reap significant savings by not needing to aerate. Aeration makes up 20 to 80 percent of wastewater treatment costs."
Van Ginkel presented the Penn State team's findings in a poster, Turning America's Waste into Energy, today (May 20) at 9 a.m . His co-authors are Dr. Oh and Dr. Bruce Logan, director of the Penn State Hydrogen Energy Center and Kappe professor of environmental engineering.
In the tests, Van Ginkel and Oh added hydrogen-producing bacteria to samples of wastewater from the Pennsylvania food processors. The bacteria were obtained from ordinary soil collected at Penn State and then heat-treated to kill all bacteria except those that produce spores. Spores are a dormant, heat resistant, bacterial form adapted to survive in unfavorable environments but able to begin growing again in favorable conditions.
"The spores contain bacteria that can produce hydrogen and once they are introduced into the wastewater, they eat the food in the water and produce hydrogen in a normal fermentation process," says Van Ginkel.