负载型纳米TiO_2光催化降解水中微量三氯乙烯

Study on Photo-catalytic Degradation of Trace Soluble Trichloroethylene in Water with Fixed Nanometer Titanium Dioxide

利用负载型纳米TiO_2作为光催化剂,对水中微量三氯乙烯进行紫外光催化降解处理。研究表明,三氯乙烯光催化降解过程符合表现一级反应动力学规律。不同的三氯乙烯初始浓度、光照强度和催化剂用量,对三氯乙烯的光催化降解具有不同的效果。在一定初始浓度范围内,随着初始浓度的增大,三氯乙烯光催化降解的反应速率常数逐渐减小;光强与反应速率常数呈正比例相关,显示出有一个最佳值;催化剂的用量与反应速率常数并非呈直线相关。此外,还讨论了三氯乙烯光催化降解的机理。

Photo-catalytic degradation experiments of trace soluble trichloroethlyene in water have been conducted by using fixed nanometer TiO2 as photocatalyst under ultraviolet light. The results revealed that the degradation process belongs to apparent first-order kinetic reaction. According to the kinetic equations and parameters, the degradation efficiencies of trichloroeth-ylene in water were changed with the different initial concentrations of trichloroethylene, different amounts of photo-catalyst and different illumination intensities. The rate constant of photo-catalytic degradation for trichloroethylene revealed inverse proportion to its initial concentration and direct proportion to the illumination intensities, but the relationship between rate constant and photo-catalyst dose did not show the direct proportion and there was an optimum value. The mechanism of trichloroethylene photo-catalytic degradation was also discussed.