Effect of anions on the oxidation of organic compounds with ultrasonically activated persulfate

Abstract

The effect of anions typically present in natural and waste waters on the oxidation of the azo dye methyl orange with persulfate activated with high-frequency ultrasound was studied. At a chloride concentration of 1 mmol/L, the rate constant of substrate oxidation increased 1.5-fold, but further increase in the chloride content retarded the process. The addition of nitrates, carbonates, and hydrogen carbonates to the solution inhibited the process (NO₃^- < HCO₃^- ~ CO₃^2-). These tendencies were in good agreement with the results obtained on a real water matrix of the natural surface water from Lake Baikal.