邻苯二甲酸酯的光降解研究

为了了解水环境中邻苯二甲酸酯(PAEs)的降解及归趋,对紫外光照射下邻苯二甲酸二甲酯(DMP),邻苯二甲酸二乙酯(DEP)和邻苯二甲酸二丁酯(DBP)的光降解过程进行了研究,并采用气相色谱-质谱联用技术分别对3种物质降解过程中生成的中间体进行了分析,提出了可能的降解机理.研究结果显示,所测试的3种邻苯二甲酸酯的降解过程均符合一级反应动力学.以UV/H2O2工艺降解DMP,浓度为10.0mg·L-1的DMP在H2O2为20.0 mg·L-1条件下,光照45min降解率可达90%以上.对邻苯二甲酸酯及H2O2的初始浓度、光照时间及pH值等因素对降解过程的影响进行了研究,以期为该方法的实际应用提供必要的基础.

Photochemical degradation of phthalates:effects of UV and hydrogen peroxide

To understand the degradation and the environmental fate of phthalic acid esters (PAEs) in water, the UV photodegradation process of dimethyl, diethyl and dibutyl phthalates (DMP, DEP, DBP) in aqueous solution was investigated. The degradation intermediates were identified with GC/MS. A plausible mechanism is suggested for the degradation of these compounds. The results showed that the degradation of the three tested phthalates follows first-order kinetics. More than 90% of DMP was degraded when a 10.0 mg·L-1 solution of DMP was irradiated under UV for 45 minutes in the presence of 20.0 mg·L-1 hydrogen peroxide. The effects of initial concentration of the phthalates and hydrogen peroxide,the time of UV radiation and pH on the degradation process are reported in order to provide the necessary basis for practical application of this method.