UV/TiO_2光催化降解水体中的邻苯二甲酸二甲酯  

Photocatalytic degradation of dimethyl phthalate(DMP) in aqueous solution by UV/TiO_2

作　　者：景伟文[1] 韩文娟[1] 

机构地区：[1]新疆农业大学化学工程学院,新疆乌鲁木齐830052

出　　处：《环境污染与防治》2013年第1期40-44,49,共6页Environmental Pollution & Control

基　　金：新疆维吾尔自治区高校科研计划青年教师科研启动基金资助项目(No.XJEDU2009S40);大学生创新基金资助项目

摘　　要：酞酸酯是环境中普遍存在的有机污染物(内分泌干扰物)之一。利用UV/TiO2光催化降解水体中的邻苯二甲酸二甲酯(DMP),讨论了溶液pH、TiO2投加量及DMP初始浓度等因素对DMP降解的影响。结果表明,DMP为10mg/L左右时,TiO2投加量为0.2～0.5g/L、pH=7是比较理想的降解条件;DMP初始浓度越高,其降解率则越低。研究了Langmuir-Hinshelwood模式下DMP在TiO2表面的吸附与催化活性的关系,发现DMP主要通过吸附在催化剂的表面而非在溶液本体中发生降解。线性回归计算所得光照条件下的吸附常数远大于无光照条件下的吸附常数,可能是由于UV和TiO2体系之间产生协同效应,提高了UV/TiO2体系对DMP的降解效果。另外,初步分析了可能的降解反应机制。Phthalic acid esters are widespread environmental organic pollutants and endocrine disrupter. In this paper, series of UV/TiO2 treatment runs were performed on dimethyl phthalate （DMP） solutions in a lab scale batch reactor to determine the effects of pH value, TiO2 dosage and DMP initial concentration on DMP photodegradation. Results showed that when the initial DMP concentration was 10 mg/L, the appropriate degradation conditions were TiO2 dosage of 0.2-0.5 g/L and pH=7. A higher DMP initial concentraton resulted in a lower photodegradation rate of DMP. The relation of TiO2 catalytic reactivity and the process of DMP adsorption onto TiO2 surface were investiga-ted by Langmuir-Hinshelwood kinetic model. It was found that the photodegradation of DMP was mainly occurred on the surface of TiO2 but not in bulk solution. The linear relationships indicated that the adsorption constant obtained from the dark adsorption isotherm was far less than that in the photocatalytic process. So, it was concluded that there might be synergies effect produced in UV/TiO2 system and the synergies effect nhanced the photodegradation of DMP. Finally, the probable degradation mechanism was primarily analyzed.

关 键 词：UV TIO2 光催化降解 邻苯二甲酸二甲酯 

分 类 号：X703[环境科学与工程—环境工程]