抗生素类化合物的光致降解机理研究

Antibiotics is a class of emerging contaminants widespread in the environment. In recent years, they have attracted much attention due to their "quasi-persistence" and drug resistance of environmental flora caused by them. The photochemical conversion is an important elimination pathway of antibiotic pollutants and has significant impact on their eco-toxicological effects. Therefore, it has significance for exposure assessment of antibiotic pollutants to reveal environmental photochemical behavior of antibiotics. In this project, transient absorption spectrum technique combined with steady-state photochemical reaction experiments will be adopted to study photodegradation reaction kinetics of representative antibiotics with different molecular structures and to systematically investigate various factors that may affect photolysis efficiency of antibiotic pollutants in water environment. This study aims to explore reaction mechanisms in photochemical transformation processes of antibiotics and to acquire related kinetics parameters for the purpose to reveal the substance that a variety of factors affect the photolysis reaction efficiency from the molecular level and thus to put forward an idealized model for predicting environmental photochemical activity of antibiotics. The objectives of this project focus on a thorough understanding of photochemical transformation and fate of typical antibiotic pollutants in natural waters, a comprehensive evaluation of the ecological toxicity of antibiotics, and a theoretical support for effective technique to remove antibiotics.

抗生素是环境中广泛存在的一类新兴污染物，近年来，由于其"准持久性"并能引起环境菌群的抗药性而备受关注。光化学转化是水环境中抗生素类污染物的重要消除途径，并显著影响此类污染物的生态毒理效应。揭示抗生素的环境光化学行为，对于该类污染物的暴露评价具有重要意义。本项目拟采用稳态光化学反应实验与瞬态吸收光谱分析技术相结合，研究和掌握水环境中分子结构不同的代表性抗生素光降解表观反应动力学规律，并系统考察可能影响其光解效率的各种因素，探讨其光化学转化过程中的微观反应机理并获得相关的微观反应动力学参数，从分子水平揭示各种因素影响光解反应效率的实质，提出一种理想化的抗生素环境光化学活性的预测模型。为全面了解自然水体中各种抗生素类化合物的光化学转化和归趋，综合评价抗生素类化合物生态毒性，寻求有效的抗生素消除工艺提供理论支持。

抗生素是环境中广泛存在的一类新兴污染物，近年来，由于其“准持久性”并能引起环境菌群的抗药性而备受关注。本项目选取典型抗生素类药物CAP、OTC和SMX，采用光化学转化探究三类抗生素在环境水体中的降解情况。采用稳态光化学反应实验和瞬态吸收光谱分析技术相结合，探究了CAP、OTC和SMX的直接光降解及其与SO4•-和HO•的间接光降解反应，同时探讨了pH、HA以及水体中常见阴离子（Cl-、HCO3-、CO32-、H2PO4-和NO3-等）对降解的影响。分析了CAP、OTC和SMX与SO4•-和HO•的光降解表观反应动力学规律，探讨了它们光化学转化过程中的微观反应机理，并获得了OTC和SMX与SO4•-的微观反应动力学参数。从分子水平出发，结合模拟化学计算和稳态化学产物分析，探讨并确定了CAP与SO4•-和HO•反应位点及反应路径。尝试了有效降解CAP、OTC和SMX的光化学方法，探究了部分抗生素光化学降解产物的生态毒性，为寻求有效的抗生素消除工艺提供理论支持。