| In this study an economical and effective photocatalytic oxidation desulphurization technique is described aimed at the SO2 pollution of our country. The photocatalytic oxidation technique has brought extensive attention because of its low energy consume, mild reaction condition, simple technique and manipulation and decreasing secondary pollution.First, two kinds of determination methods of SO2 were compared. The results showed the data were similar. Since the determination method of SO2 with iodine is more complicate, the determination method of SO2 with a set of SO2 analytic apparatus was adopted. Then photocatalytic activity of outsourcing and home-made nanometer TiO2 was compared in the same reaction condition. And the results showed photocatalytic activity of outsourcing TiO2 was better than that of home-made TiO2.It was found that the oxidation of SO2 didn't occur without ultraviolet and in the ultraviolet the oxidation of SO2 occurred whether TiO2 existed or not. The data indicated that photocatalytic oxidation of SO2 over nanometer TiO2 obeyed the rules of first order reaction kinetics and it can be reduced to a formula: In Ct /C0=-kat.The research results showed the reaction rate constant diminished with the increase of frequency of use. In addition, the deactivated photocatalysts can be regenerated to a nearly full degree by washing and drying.Effects of reaction elements on photocatalytic oxidation were studied, such as radiation intensity, reaction temperature and concentration of SO2. The research results showed that the efficiency of photocatalytic oxidation of SO2 was affected little by the radiation intensity when the initial concentration of SO2 was low. On the contrary, the efficiency increased with the increase of radiation intensity when the initial concentration of SO2 was high. In the range from 0 ℃ to 120 ℃, the efficiency of photocatalytic oxidation of SO2 increased with the increase of reaction temperature. But in the range from 120℃ to 200℃, the efficiency was not significantly affected by the reaction temperature. When the initial concentration of SO2 was below 1090mg/m3, the efficiency of photocatalytic oxidation of SO2 increased with the increase of the initial concentration of SO2 While in the range from 1090mg/m3 to 2400mg/m3, the efficiency wasnot significantly affected by the initial concentration of SO2..
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