文献类型：期刊文献

英文题名：Mechanistic and kinetic aspects of florfenicol degradation by ?OH: Chloride moiety resistance

作者：Ding, Yanzhou[1];Zhu, Yiwen[1];Yu, Xia[1,2];Lyu, Shuguang[1,2];Wu, Yanlin[3];Zhou, Lei[1,2];Sui, Qian[1,2]

机构：[1]East China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asses, Shanghai 200237, Peoples R China;[2]Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China;[3]Fudan Univ, Dept Environm Sci & Engn, Shanghai Key Lab Atmospher Particle Pollut Prevent, Shanghai 200433, Peoples R China

年份：2024

卷号：479

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001127206100001)】；

基金：This research was partly supported by the National Natural Science Foundation of China (21777042, 22076045) , Natural Science Foundation of Shanghai (23ZR1417500) , the Science and Technology Commission of Shanghai Municipality's Yangfan Special Project (23YF1408400) , Shanghai Talent Development Funding (2020051) , the Open Research Fund of State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals (2022KFYB03) , and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Hydroxyl radical; Florfenicol; Laser flash photolysis; DFT; Degradation mechanism

摘要：Antibiotic residues in aquatic environments can be effectively degraded by hydroxyl radical ((OH)-O-center dot)-based advanced oxidation processes (AOPs). However, the reaction kinetics and mechanisms have not been compre-hensive determined due to the limitations of conventional competition kinetic methods and mass spectrometry-based product identification, as these methods fail to exclude interference from secondary radicals and are unable to capture unstable intermediates or transient species. In this study, these limitations were overcome using laser flash photolysis (LFP) and density functional theory (DFT) calculations, allowing accurate determi-nation of the (OH)-O-center dot-initiated reaction kinetics and degradation mechanisms of florfenicol (FF), a model veterinary antibiotic compound that is frequently detected in the environment. Based on the LFP experiment results, the second order rate constant (k) between (OH)-O-center dot and FF was determined to be 1.96 x 10(9) M-1 s(-1) by tracking the typical signal of (SCN)(2)(center dot-). Furthermore, DFT calculations revealed two distinct mechanisms for (OH)-O-center dot addition to the benzene ring and identified hydrogen atom abstraction (HAA) reaction from chiral carbons as being the most favorable initial reaction for (OH)-O-center dot. In addition, the destruction of chlorine moiety occurred via hydroxylation-chlorine abstraction, rather than direct chlorine abstraction or substitution reactions. The resistance of chlo-rine moiety to degradation during the initial oxidation process, resulted in the formation of chlorine-containing by-products. This study provided a novel approach to comprehensively investigate the mechanisms of emerging contaminants elimination during (OH)-O-center dot-based AOPs.