Comparative study of acid blue 113 wastewater degradation and mineralization by UV/persulfate and UV/Oxone processes

Sulfate radical-based advanced oxidation processes (SR-AOPs) are powerful technologies to treat various pollutants. Among these SR-AOPs, UV/persulfate (UV/PS) and UV/Oxone were chosen to degrade and mineralize Acid Blue 113 (AB113) wastewater for their strong reactivity. The experimental setup was designed identical to compare two processes. Operating parameters such as oxidant dosage, UV intensity, initial dye concentration, and pH were studied to evaluate their effects on degradation and mineralization of AB113. The results demonstrated powerful degradation of AB113 and mineralization rate for both UV/PS and UV/Oxone processes. However, reaction with either UV irradiation alone or persulfate alone can reach low removal efficiency of AB113. But Oxone oxidation alone can achieve about 95% of AB113 removal efficiency. For both UV/PS and UV/Oxone processes, the higher the oxidant dosage applied, the higher the AB113 and TOC removal efficiencies can be obtained up to the optimal dosage. On the other hand, the AB113 removal efficiency and reaction rate constant decreased with increasing in the initial AB113 concentration. The initial pH showed no significant effect on AB113 removal efficiency. UV/Oxone process was observed to be more sensitive to UV intensity and pH on TOC mineralization. The lower UV power conducted lower TOC mineralization.