水环境中典型紫外吸收剂的光致降解机理研究

Organic ultraviolet (UV) filters are a class of emerging contaminants widespread in the environment. They have attracted much attention due to their bioaccumulation, endocrine disrupting activity and toxicological effects. The photochemical conversion is an important elimination pathway of UV filters. Therefore, it has significance to investigate the mechanism of photodegradation of UV filters. In this project, benzophenone-3 (BP-3) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB) are examined. Aims of this study are to elucidate the photodegradation mechanism of typical UV filters in water environment: (a) to investigate various factors that may affect photolysis efficiency and study photodegradation reaction kinetics of UV filters by steady-state photochemical degradation experiments, (b) to explore the microscopic reaction mechanism of UV filters with different activated species in water with transient absorption spectrum technique, (c) to identify the corresponding phototransformation products with analytical method of GC-MS, LC-MS, nuclear magnetic resonance, etc, and acquire the phototransformation apprent and mcroscopic kinetics parameters. This study would not only offer theoretical basis for thorough understanding of photochemical transformation and fate of UV filters, but also open up new idea for control and eliminate UV filters contamination in environment.

紫外吸收剂是环境中广泛存在的一类新兴污染物，由于其具有生物累积性、内分泌干扰性及毒性，已经引起了环境科学工作者的关注。光化学转化是水环境中紫外吸收剂类污染物的重要消除途径，因此研究紫外吸收剂的光化学降解机理具有重要意义。本项目拟选取代表性的紫外吸收剂二苯酮-3（BP-3）和二乙氨基羟苯甲酰基苯甲酸己酯（DHHB），通过稳态光化学降解实验，探明可能影响水环境中紫外吸收剂光降解效率的各种因素，研究其光降解表观反应动力学规律；采用纳秒级瞬态吸收光谱等分析技术，探究紫外吸收剂与水环境中不同活性物种发生作用的微观反应机理；通过GC-MS、LC-MS、核磁共振等分析手段鉴定光转化产物，获得光转化表观反应动力学和微观反应动力学参数；从而阐明水环境中典型紫外吸收剂的光致降解机理。本研究不仅为全面了解水环境中紫外吸收剂的光化学转化和归趋提供理论依据，也可为控制与消除环境中紫外吸收剂的污染控制技术开辟新思路。

紫外吸收剂是环境中广泛存在的一类新兴污染物，由于其具有生物累积性、内分泌干扰性及毒性，已经引起了环境科学工作者的关注。光化学降解是水环境中紫外吸收剂类污染物的重要消除途径，因此研究紫外吸收剂的光降解效果和降解机理具有重要意义。本项目选取了代表性的紫外吸收剂二苯酮-3（BP-3）、二乙氨基羟苯甲酰基苯甲酸己酯（DHHB）和对氨基苯甲酸（PABA），通过稳态光化学降解实验，探明了可能影响水环境中紫外吸收剂BP-3和DHHB光降解效率的各种因素，研究了其光降解表观反应动力学规律；采用纳秒级瞬态吸收光谱等分析技术，研究了紫外吸收剂BP-3和DHHB与水环境中不同活性物种发生作用的微观反应机理；同时，探究了UV254/Fe2+/PS体系对水相中PABA的降解效果和降解机理；通过GC-MS、LC-MS、核磁共振等分析手段鉴定光降解产物，获得了光转化表观反应动力学和微观反应动力学参数；从而阐明了水环境中典型紫外吸收剂的光致降解机理。本研究不仅为全面了解水环境中紫外吸收剂的光化学降解和归趋提供理论依据，也可为控制与消除水环境中紫外吸收剂的污染控制技术开辟新思路。