WASHINGTON, March 1, 2011 -- The latest episode in the American Chemical Society's (ACS) award-winning podcast series, "Global Challenges/Chemistry Solutions," focuses on the discovery that household sewage has far more potential as an alternative energy source than previously thought.

Scientists say the discovery, which increases the estimated potential energy in wastewater by almost 20 percent, could spur efforts to extract methane, hydrogen and other fuels from this vast and, as yet, untapped resource. Their report appears in ACS' journal Environmental Science & Technology.

Elizabeth S. Heidrich of Newcastle University in the United Kingdom and colleagues note that sewage treatment plants in the United States use about 1.5 percent of the nation's electrical energy to treat 12.5 trillion gallons of wastewater a year. "Instead of just processing and dumping this water, we suggest that in the future treatment facilities could convert its organic molecules into fuels, transforming their work from an energy drain to an energy source," she said. "Based on our research, we estimate that one gallon of wastewater contains enough energy to power a 100-watt light bulb for five minutes."

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This podcast is available without charge at iTunes and from ACS' website at www.acs.org/globalchallenges.

Global Challenges/Chemistry Solutions is a series of podcasts describing some of the 21st Century's most daunting problems, and how cutting-edge research in chemistry matters in the quest for solutions. Global Challenges is the centerpiece in an alliance on sustainability between ACS and the Royal Society of Chemistry. Global Challenges is a sweeping panorama of global challenges that includes dilemmas such as providing a hungry, thirsty world with ample supplies of safe food and clean water; developing alternatives to petroleum to fuel society; preserving the environment and assuring a sustainable future for our children; and improving human health.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.