紫外光和光氧化剂对水中氯仿及三氯乙烯和四氯乙烯的光降解作用

为了探讨明紫外光和光氧化剂对卤烃光降解的影响，以H2O2和H2O2／草酸铁络合物为光氧化剂，研究了紫外光对氯仿、三氯乙烯和四氯乙烯的降解。结果表明，紫外光，紫外光／H2O2体系能有效地加速水溶液中三氯乙烯和四氯乙烯的光降解，但不能降解氯仿；而紫外光／H2O2／草酸铁或紫外光／草酸铁络合物体系能有效地使水溶液中氯仿，三氯乙烯和四氯乙烯烃迅速光解脱氯；溶液PH值对卤烃光解有显著影响，PH值为2．5－3．5时光解速率最快，随着H2O2质量浓度的增加，卤烃光解速率提高，但H2O2增大到一定质量浓度时，其脱氯量反而降低。

Photo-Degradation of Chloroform, Trichloroethylene and Tetrachloroethylene in Water by UV and Photo-Oxidants

The photo degradation of chloroform, trichloroethylene and tetrachloroethylene by H 2O 2 and H 2O 2 ferrioxalate complexes as photo oxidants under irradiation of UV was compared. The results show that the photodegradation of two kinds of chloroethylene in aqueous solution by UV, UV/ H 2O 2 is very effective;the photodegradation of chloroform by the photo oxidants is not obvious;the photodegradation of three kinds of chloronated hydrocarbons by UV/ H 2O 2 /ferrioxalate or UV/ferrioxalate complexes is very significant. pH has significant effects on the photo degradation of halogenated hydrocarbons and the highest rate of photo degradation happens at pH 2.5~3.5. The rate of photo degradation of halogenated hydrocarbons increases with the rice of H 2O 2 concentration, but the amount of dechloridation decreases when the concentration of H 2O 2 reaches a certain level.