Kinetics in Mn (II) ion catalytic ozonation of Papermaking Tobacco Slice wastewater

This study elucidated the Chemical Oxygen Demand (COD) degradation efficiency of the Papermaking Tobacco Slice (PTS) wastewater with Mn (II) ion catalyzed ozonation. The effect of catalyst dosage and initial pH on COD removal was investigated. The results reveal that COD removal was effected by initial pH value and Mn (II) ion can promote COD removal rate. In Mn (II) ion catalytic ozonation system, three types of oxidants, including hydroxyl radicals, manganese ions and ozone, contribute to the oxidation reactions of pollutants in the PTS wastewater and both the manganese ions and hydroxyl radicals are the more important oxidants for COD removal than ozone. Moreover, manganese ions play a more important role for the COD removal than hydroxyl radicals under neutral and alkaline condition, especially at pH 7, at which the contribution ratio of molecular ozone, hydroxyl radicals and manganese ions is 1:2.32:4.96.