Fabrication of SnO2-Sb reactive membrane electrodes for high-efficiency electrochemical inactivation of bacteria and viruses in water

Abstract

Exposure to waterborne pathogens is still a widespread threat to public health, and efficient and reliable disinfection technologies are urgently needed for decentralized applications. Herein, we developed a novel freestanding and flow-through SnO2-Sb reactive membrane electrode (RME) for electrochemical wastewater disinfection. When water was forced to flow through the porous RME, large amounts of reactive ·OH and H+ were generated within the interior pores of the anode, creating a strongly acidic local environment enriched with ·OH for the rapid inactivation of bacteria and viruses. At an applied voltage of 3.5 V, 100% removal of Escherichia coli (>6.3-log inactivation) was achieved by the flow-through RME at a high flux, which was significantly more effective than the system operated in the conventional flow-by mode (2.7-log inactivation). Using the bacteriophage MS2 strain as a model virus, a disinfection efficiency of 100% (>8.3-log inactivation) was achieved by the RME at 3.5 V. The transmission electron microscopy analysis revealed that E. coli and MS2 in the disinfected water suffered from serious destruction and disintegration, reflecting the strong electrocatalytic oxidation capacity of the charged RME. The SnO2-Sb RME-based electrochemical system performed very well in disinfecting complex municipal wastewater, demonstrating its potential for practical applications.