Self-powered electrochemical water treatment system for sterilization and algae removal using water wave energy

Abstract Marine environment is facing a great challenge from rapid population growth and increased human activities. The uncontrolled discharge of wastewater and ballast water has caused the growth of harmful bacteria and algal blooms. Here we report a self-powered electrochemical water treatment system for sterilization and algae removal in wastewater using the newly invented triboelectric nanogenerator (TENG) that provides the power from the water wave. A synergetic effect of both free chlorine and reduced graphene oxide during the electrolysis process resulted in an effective impact to bactericidals and high-efficiency algae removal. This system achieves more than 6 log (99.9999%) removal of three model bacteria, including Escherichia coli , Streptococcus faecalis and Vibrio alginolyticus , and high removal efficiencies for mixed marine algae. Our study demonstrates an innovative and unique approach toward a totally self-powered electrochemical water treatment system for bacterial inactivation and algae removal without supplying additional power. This is a step toward self-powered environmental electrochemistry.