Generations of Reactive Species Under High-Voltage Nanosecond Pulse Discharge in Gas–Liquid–Solid Three-Phase

In this paper, a high-voltage nanosecond pulsed power supply was used to excite a wire-tube reactor in a gas–liquid-solid three-phase to generate reactive species in treated water. Especially, the concentrations of O3, H2O2 and HNOx in treated water were examined. The results show that the concentrations and energy efficiency ratios of the H2O2 and HNOx in the treated water showed a decreasing trend, while those of the O3 did not change much by fixing the liquid conductivity as 100.0 μS/cm and increasing the water content (5–85%), under the experimental conditions of the applied voltage as 18.5 kV, the total gas–liquid flow rate as 2.00 LPM, and using SiO2 spheres as the solid-phase filler. Moreover, the concentrations and energy efficiency ratios of H2O2 and HNOx in the treated water showed a tendency to increase and then decrease by fixing the water content of gas–liquid at 45% and increasing the liquid conductivity from 2.00 to 800.0 μS/cm. The maximum concentrations of both H2O2 and HNOx were occurred at the conductivity as 100.0 μS/cm. The concentrations of O3 showed a slow increase, and its energy efficiency ratios were first constant and then increased slowly. This work can provide an experimental reference for the application of plasma in the environmental field.