Indigo carmine solution treatment by nanosecond pulsed power with a dielectric barrier electrode

Water pollution is a major environmental issue around the world. We have studied water treatment using nanosecond pulsed power. Discharge plasmas generated by the nanosecond pulsed power efficiently produce active species that are applicable to water treatments. In this study, device with a dielectric barrier was compared with that without a dielectric barrier. Indigo carmine solution was treated by two systems with nanosecond pulsed power. The treatment efficiency of the system with a dielectric barrier was lower than that without a dielectric barrier, although spark discharges were suppressed in the reactor. Considering the energy transfer ratio to discharges and the configuration of thinner reactor and smaller volume, the treatment efficiency using a dielectric barrier would not be low. According to absorbance at 288 nm, which is the specific absorbance wavelength of indigo carmine solution, the absorbance in using an oxygen working gas decreased faster than that using nitrogen.