Mn2+/H2O2/O3, a high efficient advanced oxidation process in acidic solution

Mn2+/H2O2/O3, an ozone-based advanced oxidation process, was investigated in acidic solution. Acetic acid (HAc) was selected as the target compound to be degraded because it is often the final product of macromolecules degraded by chemical oxidation. The results showed that only Mn2+/H2O2/O3 could effectively remove acetic acid at initial pH 1.0, while others like O3, H2O2/O3, Mn2+/O3 and Mn2+/H2O2 almost had no removal ability, indicating that the coexistence of Mn2+, H2O2 and O3 was of great necessity to ensure the high removal rate of acetic acid in acidic solution. Optimized parameters suggested that there existed an optimal ratio of concentration of Mn2+ to concentration of H2O2 for acetic acid removal. The above results are of significance for effective treatment of acidic wastewater containing refractory pollutants. The mechanism study showed that Mn2+/H2O2/O3 in acidic solution was not associated with the generation of hydroxyl radicals, but with the generation of highly active intermediate Mn3+.