Employing a novel nanocatalyst (Mn/Iranian hematite) for oxidation of SO2 pollutant in aqueous environment

In this project, the oxidation of SO2 pollutant by Mn/Iranian hematite (Mn/IH) as a novel nanocatalyst in aqueous solution was investigated and followed by conductometry in a semi-batch reactor. The removal of SO2 gas is very important for decreasing the environmental pollution. The Mn/IH was prepared by coprecipitation method, and a novel way was used for converting SO2 to sulfuric acid as an energy source. The characterization of catalyst was determined by X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy and X-ray fluorescence techniques. A Box-Behnken design was used to reduce the number of test runs and optimize the influencing factors such as the amount of nanocatalyst, temperature and the reaction time in oxidation of SO2. The graphical counter plots and response surface were used to determine the optimum conditions. Analysis of variance showed a high determination coefficient value (, and for oxidation of SO2) and satisfactory prediction second-order regression model. Based on the optimum results, the maximum efficiency for oxidation of SO2 was 90.67%, and it was achieved at initial temperature of 286.03 K, concentration of Mn/IH at 951.11 mg/l and 35.75 min of reaction. The results showed that the temperature had the most significant effect on SO2 oxidation compared with the other two variables.