克百威光催化降解动力学的研究

采用TiO2光催化技术对克百威的降解进行了研究,并系统地考察了催化剂用量,溶液初始pH值,底物浓度,活性氧物种和各种阴阳离子对其降解动力学的影响.用Langmuir-Hinshelwood动力学模型对克百威的光催化降解进行了研究,结果表明,克百威在弱碱性条件下降解速率最快,×OH对克百威降解贡献比约为93.4%,h+和其他ROSs的贡献则相对较小.而水溶液中的阴离子BrO3-和S2O82-对克百威的光催化降解有促进作用,I-则有明显的抑制作用,并且水溶液中的K+,Ca2+,Na+,Mg2+和Cu2+等金属阳离子对克百威的降解也均体现了一定程度的抑制作用.

Parameters effect on photocatalytic degradation kinetics of carbofuran in TiO2 aqueous solution

Photocatalytic degradation of carbofuran has been investigated in TiO2 aqueous solution under UV irradiation. The effects of various parameters such as catalyst amount, pH value, concentration of carbofuran, reactive oxidative species (ROSs), different anions and metal cations on photocatalytic degradation kinetics were studied. The degradation of carbofuran follows pseudo first-order kinetics by using Langmuir-Hinshelwood model. The results indicated that the weak alkaline solution was favor for the degradation of carbofuran. The ?OH radical is responsible for the major degradation of carbofuran, and its contribution is about 93.4%, while the other ROSs play a minor contribution to the degradation. Additionally, the anions of BrO3- and S2O82- accelerate the degradation rate of carbofuran, while I- anion inhibits degradation reaction obviously. The photocatalytic degradation reactions were also inhibited to some extent when K+, Ca2+, Na+, Mg2+ and Cu2+ cations were added to aqueous solution.