Drinking water disinfection by hemin-modified graphite felt and electrogenerated reactive oxygen species

The electrochemical inactivation of microorganisms by a hemin/graphite felt (GF) composite electrode was investigated, and Escherichia coli was treated as the testing species. The composite electrode was constructed by chemically bonding hemin molecules onto an amino-mineralized GF (AGF) surface. Then, the electrode was characterized systematically by electrochemical methods, and the kinetic parameters of the modified electrode were investigated. The hemin molecules on the surface of the composite electrode have high activity for the reduction of O 2 . When the composite electrode was applied with negative potentials, the dissolved oxygen was electrochemically reduced to reactive oxygen species (ROS, such as H 2 O 2 and OH) at the cathode surface. The ROS can cause biological damage and can eventually result in the death of bacteria. A sterilizing rate up to 99.9% could be obtained after 60   min of inactivation. Thus, this composite electrode could be applied to disinfect drinking water efficiently at a low potential (−0.6   V vs. SCE) without any addition of chloride.