抗生素不同解离形态在水环境中的光化学行为

Aqueous environmental photochemical behavior of different antibiotic dissociation forms

表层水体中存在众多可解离的有机污染物,揭示其不同解离形态的环境光化学行为,对于污染物的环境持久性和风险评价具有重要意义.抗生素是在水环境中广泛存在的新型有机污染物,其中氟喹诺酮类(FQs)、磺胺类(SAs)、四环素类(TCs)等抗生素因分子结构中含有羧基、羟基和/或氨基等可电离基团,在水中以多种解离形态共存而备受关注.抗生素的多种解离形态不仅以不同的丰度共存于环境表层水体中,而且不同的解离形态表现出相异的环境光化学转化行为和风险.本文总结了水环境中可解离抗生素光化学行为研究的最新进展,介绍了pH值对直接和间接光解动力学的影响,着重评述了抗生素不同解离形态的光化学反应动力学、转化产物和路径,讨论了可解离抗生素光化学转化的环境半减期和风险,最后对抗生素不同解离形态的光化学行为研究进行了展望.

Numerous ionizable organic pollutants are present in the aqueous environment.Revealing the environmental photochemical behavior of their different dissociated forms is of great significance to assess the environmental persistence and risk of these pollutants in aquatic systems.Antibiotics are emerging pollutants that are ubiquitous in natural waters.Among them,fluoroquinolones(FQs),sulfonamides(SAs),tetracyclines(TCs)and many other antibiotics have attracted increasing attention because their molecular structures contain ionizable groups such as carboxyl,hydroxyl and/or amino groups.Various dissociation forms of antibiotics not only coexist in surface waters with different abundances,but also show different environmental photochemical transformation behavior and risk.In view of this,this paper summarizes the latest progress on the aqueous photochemical behavior of ionizable antibiotics,introduces the influence of pH on the direct and indirect photolysis kinetics,and highlights the photochemical reaction kinetics,transformation products and pathways of different antibiotic dissociation forms.Also,the corresponding environmental phototransformation fate and risk of ionizable antibiotics are discussed.Finally,the research prospects about the photochemical behavior of antibiotic dissociation forms are proposed.