UV-Fenton法降解对硫磷的机理及动力学

采用UV-Fenton法对对硫磷的氧化消除及动力学规律进行研究,利用气相色谱法测定对硫磷的浓度,以半衰期的大小来表示降解效果;并考察了Fe2+浓度、H2O2浓度以及pH对光解对硫磷的影响.结果表明,UV-Fenton对对硫磷的氧化降解过程符合一级反应动力学;溶液中Fe2+与H2O2浓度对降解反应影响较大,随着浓度的增加对硫磷的降解效果增大,一定程度后呈下降趋势;在pH=3时,对硫磷的降解效果最好,其半衰期可达到0.256 h,一级动力学方程可表示为Ct=4.9652e-2.7 066t.

Mechanism and kinetics of parathion degradation by UV-Fenton treatment

The mechanism and kinetics of parathion degradation by UV photolysis combined with Fenton reagent oxidation were investigated. The concentration of parathion was determined by GC, and the effects of oxidizing degradation were indicated by the half-life. Factors influencing the photolysis, such as concentrations of Fe2+, H2O2 and pH, were studied. The results showed that the oxidation of parathion followed pseudo-first-order kinetics. The concentration of Fe2+ and H2O2 influenced the oxidation of parathion greatly, and increasing Fe2+ and H2O2 concentrations favored the oxidation. The efficiency of oxidizing degradation was reduced by increasing Fe2+ and H2O2 by some extent; The optimum oxidizing degradation process occurred at pH =3, where the half-life was 0.256 h. The pseudo-first-order kinetics equation was Ct = 4.9652e-2.7066t.