A new study by researchers at Princeton University and Tsinghua University demonstrates that sludge and reclaimed water from wastewater treatment plants in China can be used as fuel and water sources at coal-fired power plants. Using such sources can save significant amounts of water, cut operating costs, and reduce greenhouse gas emissions, the researchers say.
The study, by Yang Guo, a postdoctoral researcher in Denise Mauzerall’s lab, analyzed data from about 2,400 coal-fired power plants and 4,200 municipal wastewater treatment plants throughout China.
By connecting these two industrial processes, wastewater treatment plants can provide a steady source of reclaimed water for cooling coal power plants, reducing freshwater consumption by about 60%.
Using waste sludge as a fuel source instead of coal, they found, could also deliver greenhouse gas emission reductions.
“The energy–water infrastructure symbiosis we propose is a step towards an urban eco-transition that will facilitate more sustainable urban systems as society transitions away from fossil fuels entirely,” said Mauzerall.