An LSU engineering professor is discovering there is enough energy in wastewater, seawater and river water to power large cities.
LSU says that with funding from the Louisiana Board of Regents, civil and environmental engineering assistant professor Xiuping Zhu is researching how to develop a new battery system to harvest energy from seawater and river water.
When two waters of different salt concentrations—such as seawater and river water—combine, Zhu says, there is a release of free energy driven by the difference in chemical potentials, called salinity gradient, or SG, energy.
The extractable SG energy between seawater and river water globally is equivalent to 3% of global electricity consumption, she says. It’s also enough energy to light 55 percent of U.S. households.
Zhu’s new system for recovering this type of energy would involve “salinity gradient batteries.”
“The success of this project could have important implications for global energy production using environmentally friendly technologies,” Zhu says.
Zhu has also discovered that energy from wastewater can be used to power the treatment of wastewater. She is proposing an energy-sustainable wastewater treatment process to remove pollutants and recover nutrients.