UV-C辐照降解水中2,4,6-三氯酚

Degradation of 2,4,6-trichlorophenol in water by UV-C irradiation

采用UV-C辐照降解水中2,4,6-三氯酚(2,4,6-TCP),考察了UV光强、2,4,6-TCP初始浓度、反应液pH值、水中阴离子和阳离子对降解效果的影响.结果表明:UV-C辐照降解2,4,6-TCP符合拟一级反应动力学,在光强为142μW.cm-2,2,4,6-TCP初始浓度为1mg.L-1条件下,辐照120min后2,4,6-TCP的去除率达到76.89%.通过增大紫外光强和减小2,4,6-TCP初始浓度,可提高反应速率和2,4,6-TCP去除率.碱性条件更利于UV-C辐照降解2,4,6-TCP.水中各种离子的存在对2,4,6-TCP的光解速率有较大的影响,其中SO42-,HCO3-,CO32-和Fe3+对反应起促进作用,Fe3+促进效果最明显.

The degradation of 2,4,6-trichlorophenol （2,4,6-TCP） was degradateted by UV-C irradia- tion in aqueous solutions. The effects of irradiation intensity, 2,4,6-TCP initial concentration, pH value,cations and anions on the removal of 2,4,6-TCP were evaluated. The results indicate that the UV-C degradation of 2,4,6-TCP well follows pseudo first order kinetic. Under the conditions of 142 μW· cm^（-2） irradiation intensity and 1 mg·L^（-1） 2,4,6-TCP initial concentration, the 2,4,6-TCP removal reaches 76.89 %. The photodecomposition rate and removal of 2,4,6-TCP can be enhanced by increasing UV-C irradiation intensity and decreasing 2,4,6-TCP initial concentration. The pH value of the solution greatly influences the 2,4,6-TCP degradation and the degradation performs well in alka- line condition. Irons in water have a significant influence on the 2,4,6-TCP degradation by UV-C irradiation. SO4^（2-） , HCO3- , CO3^（2-） and Fe^（3＋） promote the 2,4,6-TCP degradation,and Fe^（3＋） has the most obvious promoting effect.