Comparison of Advanced Oxidation Methods (AOPs) of Persulfate in Removal of Color in Municipal Wastewater

Conventional wastewater treatment methods usually cannot meet the standards required by environmental organizations. Therefore, in this study, the efficiency of advanced oxidation methods using persulfate by various activators of hydrogen peroxide, UV, and ozone in the tertiary treatment of municipal wastewater was investigated. Also, the effects of contact time, solution pH, and the molar ratio of oxidants on the color removal were evaluated. The results showed that the highest color removal was obtained in H2O2/S2O82- with a molar ratio of 1.06 to 1 for three processes of H2O2/S2O82-, UV/H2O2/S2O82- and O3/H2O2/S2O82- in solution pH of 9. A comparison of different systems showed the highest color removal efficiency followed the order of O3/H2O2/S2O82- >UV/H2O2/S2O82- >H2O2/S2O82-. The results showed that activating agents and persulfate have a significant effect on the removal of color in wastewater treatment. Therefore, tertiary wastewater treatment by these processes can effectively reuse wastewater in agriculture and aquaculture.