氙灯/TiO_2体系下敌草隆光催化降解动力学的研究

Photocatalytic Degradation Kinetics of Diuron by TiO_2 and Simulated Sunlight

利用光催化技术通过单因素和中心复合实验对敌草隆的降解动力学进行了研究.在单因素实验中,通过Langmuir-Hinshelwood动力学模型对敌草隆的光催化降解进行了模拟,并系统地考察了催化剂用量、溶液初始pH值和温度对其降解动力学的影响,结果表明,敌草隆的光催化降解符合假一级动力学,中性条件有利于敌草隆的光催化降解,并且随着温度的升高敌草隆光催化降解速率增大;而中心复合实验则着重探讨3个单变量之间相互作用的关系,通过建立数学模型得到敌草隆光催化降解的最佳条件为:TiO2浓度2.98 g·L-1,溶液初始pH=7.78,反应温度为40℃.

Photocatalytic degradation kinetics of diuron in aqueous solution was systematically investigated using TiO2 as the photocatalyst.The single-variable-at-a-time（SVAT） method and the central composite design（CCD） based on response surface methodology（RSM） were employed to study the individual and synergistic effects of several classical parameters on photocatalytic efficiencies.Three different parameters,namely TiO2 concentration,pH value and initial temperature of the model pollutant,were found to independently determine the degradation efficiencies.From the SVAT experiments,it could be concluded that neutral solutions were favorable for the degradation of diuron,and the degradation rate increased with the increasing temperature.Moreover,the results from CCD indicated that the optimum degradation conditions were as follows： TiO2 concentration at 2.98 g·L-1,pH value at 7.78,and temperature at 40℃.