Spectroscopic Measurements of Dissolved O₃, H₂O₂ and OH Radicals in Double Cylindrical Dielectric Barrier Discharge Technology: Treatment of Methylene Blue Dye Simulated Wastewater

Advanced oxidation technologies (AOTs) focusing on nonthermal plasma induced by dielectric barrier discharge are adequate sources of diverse reactive oxygen species (ROS) beneficial for water and wastewater treatment. In this study, indigo, peroxytitanyl sulphate and terephthalic acid methods were used to approximate the concentrations of O₃, H₂O₂ and OH produced in a double cylindrical dielectric barrier discharge (DCDBD) plasma configuration. The effect of pH and scavengers as well as the amount of chemical probes on the generation of oxidants was investigated. The efficiency of the DCDBD reactor was further evaluated using methylene blue (MB) as model pollutant. The results demonstrated that the formation of oxidants O₃, H₂O₂ and OH in the DCDBD reactor was pH-dependent. Furthermore, the presence of scavengers such as phosphates, bicarbonates and carbonates in the solution diminished the amount of OH in the system and hence could impact upon the degree of detoxification of targeted pollutants during water and wastewater treatment. The MB simulated dye was totally decomposed into H₂O, dissolved CO₂ and simpler aqueous entities. Herein the DCDBD design is an adequate AOT that can be used worldwide for effective decontamination of water and wastewater.