US researchers convert wastewater to energy

BBC : Researchers at the Pennsylvania State University have developed a prototype device that can simultaneously treat wastewater and generate electricity. They employed reverse electrodialysis (RED), which is commonly used to desalinate seawater. In that process, fresh water and salt water are put in chambers separated by membranes, and an electrochemical charge is created by the flow of ions that results. Replacing the seawater with ammonium bicarbonate, the researchers combined the RED membrane stacks with microbial fuel cells (MFCs), which convert chemical energy to electrical energy by the catalytic reaction of microorganisms. “In our process, we have the MFC part which is treating waste water and creating energy, and we have the RED stack which is just boosting that process, it’s making it happen more efficiently,” said Bruce Logan, one of the authors of a paper published in Science. The group hopes its device could be used in developing countries to provide clean water and power for homes.