The mixed phase nano TiO2 with different crystalline phases was synthesized by sol-gel method under different calcination temperature,and was used for degradation of gas phase benzene under ultraviolet light. The effects of initial benzene mass concentration,ultraviolet light intensity and catalyst amount on the benzene removal rate were investigated. The kinetic characteristics of photocatalytic degradation of gaseous benzene were investigated. The results showed that:The catalyst prepared by calcination at 450 ℃ had the highest degradation efficiency of benzene,and the mass fraction of rutile phase of the catalyst was 6.30%;The benzene removal rate reached 99.73% under the optimum conditions of 74.39 mg/m^3 of initial benzene mass concentration,7 g of catalyst addition and 2.18 klux of light intensity and 84 min of reaction time;The relationship between photocatalytic degradation rate and light intensity accorded with the 0.5 level kinetic characteristics;When the catalyst amount was 3 g,the mass of benzene degraded by unit time unit mass catalyst was the most;The photocatalytic degradation of benzene was consistent with first-order kinetic equation.
Environmental Protection of Chemical Industry