Research on different oxidants synergy with dielectric barrier discharge plasma in degradation of Orange G: Efficiency and mechanism

A coupling technique of introducing an oxidant into dielectric barrier discharge (DBD) plasma was studied to enhance the degradation of Orange G (OG) in aqueous solution. We evaluated the main effect of oxidants on the degradation of OG. Experiments showed that an appropriate amount of oxidant in DBD showed a significant synergistic effect, which improved the degradation efficiency and kinetics of OG. Increasing the voltage was beneficial to promote the degradation of OG. After 10 min of treatment, when the PS, SPC and Fe(VI) were 0.15, 0.10, 0.10 mM and the voltage was 70 V for 100 mg/L OG, the degradation efficiency reached 64.6%, 81.7% and 96.5%, respectively. After adding the oxidant, the synergy factor was greater than 1, and the energy yield got improvement. In addition, the quantitative determination of H2O2 and O3 and free radical scavenger test explained its mechanism of reaction. The results confirmed that the addition of oxidants could increase the production of active species, and the production of active substances had a significant impact on the removal of OG. The results showed that the addition of Fe(VI) showed higher degradation efficiency and energy yield in promoting OG degradation, while the effect of adding PS was relatively weak.