Application of submerged plasma irradiation process for RNO treatment from an aqueous solution

Abstract

This study attempted to remove an organic from an aqueous solution (wastewater) using submerged plasma irradiation (SPI) process. N,N-Dimethyl-4-nitrosoaniline (RNO) was used as a target material. Effect of electrode materials, applied voltage, initial concentration, and two types of buffer solutions were studied with the purpose of monitoring the pollutant removal. The degradation of RNO by SPI process followed a first-order kinetics model. While applying SPI, in comparison with the alkaline condition (carbonate buffer), the neutral condition (phosphate buffer) proved to be much more applicable in dealing with RNO contained by wastewater. After 8 min of operation, the removal efficiencies were found to be over 70% in the case of the carbonate buffer solution, and respectively 90% in the case of the phosphate one. By increasing the operation time and applied voltage, the SPI process had a significant effect on the pollutant removal. In comparison with the tungsten and aluminum electrodes, the iron one showed a higher efficiency in the removal process. Instead of using a high concentration pollutant in the initial stage, it was more beneficial to dilute the RNO wastewater before applying the SPI method.