中压紫外/过氧乙酸降解水中氟喹诺酮类抗生素的特性与机理

The occurrence of fluoroquinolone antibiotics (FQs) in the source water has posed a threat to the safety of the water supply in China. With respect to this current situation, this study will employ the medium pressure UV/peracetic acid (MPUV/PAA) process, a new advanced oxidation process, to degrade FQs in water. The typical FQs will be chosen as the target compounds. In this work, the degradation efficiency of the target FQs by MPUV/PAA will be investigated, and the effects of water matrices and operational parameters on the degradation will also be evaluated. Quenching studies will be carried out to investigate the contribution of different active species to the degradation of target compounds. The possible transformation products of the target FQs will be identified using LC-MS/MS, and the potential degradation pathways will be proposed. And there is a need to investigate the relationship between the active species and the transformation products. The changes in antibacterial activity of the target FQs during the MPUV/PAA process will be measured by the antibacterial activity test, and the changes in genotoxicity will be monitored by the SOS/umu test. In addition, the toxicity of the transformation products will be predicted by using QSAR analysis softwares. The goal of this work is to contribute to a comprehensive understanding of the degradation of FQs by MPUV/PAA, which can provide some basic information for the future studies and applications.

我国水源水中氟喹诺酮类抗生素（Fluoroquinolones，FQs）的残留问题对供水水质安全造成了威胁。针对这一现状，本研究构建了中压紫外/过氧乙酸（MPUV/PAA）高级氧化新技术来实现对水中FQs类污染物的控制。课题选取了FQs中的典型代表药物作为目标物，考察MPUV/PAA技术对典型FQs的降解效能，考察水质条件和工艺参数对降解的影响；通过自由基捕获实验等手段，考察不同活性物种对降解反应的贡献；通过液质联用技术，鉴别目标FQs的降解产物，推断污染物的降解途径，探究活性物种与中间产物的关系；采用体外抑菌实验和SOS/umu测试，分别考察目标FQs在MPUV/PAA体系中抑菌活性和遗传毒性的变化，同时结合定量构效关系（QSAR）分析软件，对降解产物的毒性水平进行预测。本研究旨在实现对MPUV/PAA新技术降解FQs类污染物的系统、全面的考察，为今后的研究与应用提供基础数据和科学依据。

针对我国水环境中氟喹诺酮类抗生素（Fluoroquinolones，FQs）的残留问题，本研究构建了中压紫外/过氧乙酸（MPUV/PAA）高级氧化新技术来实现对水中FQs类污染物的控制。课题选择左氧氟沙星（LEV）和诺氟沙星（NOR）作为目标FQs。研究表明，MPUV/PAA体系可以有效降解NOR和LEV。•OH是在酸性条件下MPUV/PAA降解目标FQs的主要自由基，而在碱性条件下，有机自由基则成为了发挥降解作用的主要自由基。提高PAA投加量和降低目标FQs浓度能够促进MPUV/PAA对目标FQs的降解。发现pH是影响MPUV/PAA降解的关键性因素，较高的pH有助于促进目标FQs的降解。Cl–和CO32–/HCO3–对MPUV/PAA降解目标FQs的影响有限。哌嗪环的转化是MPUV/PAA降解目标FQs的最主要途径，此外，pH的改变会对MPUV/PAA降解FQs的产物类型和降解路径产生重要影响。根据QSAR分析，大多数目标FQs的降解产物的生物毒性低于母体化合物。本研究全面考察了MPUV/PAA新技术降解FQ的特性与机理，为今后的研究与应用提供基础数据和科学依据。