DOI: 10.1016/j.watres.2018.02.008
Scopus记录号: 2-s2.0-85042314575
论文题名: Aqueous photodegradation of substituted chlorobenzenes: Kinetics, carbon isotope fractionation, and reaction mechanisms
作者: Passeport E. ; Zhang N. ; Wu L. ; Herrmann H. ; Sherwood Lollar B. ; Richnow H.-H.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 135 起始页码: 95
结束页码: 103
语种: 英语
英文关键词: Chlorobenzenes
; OH radicals
; Photodegradation
; Stable isotope
; Water quality
Scopus关键词: Activation energy
; Carbon
; Free radicals
; Impurities
; Nitrogen oxides
; Photodegradation
; Photolysis
; Rate constants
; Surface waters
; Water pollution
; Water quality
; Carbon isotope fractionation
; Chlorobenzenes
; Compound specific isotope analysis
; In-laboratory experiments
; OH radical
; Pseudo-first order reactions
; Stable isotopes
; Surface water contaminants
; Isotopes
; 1 chloro 4 nitrobenzene
; benzene
; carbon
; chlorobenzene
; electrophile
; hydroxyl radical
; carbon
; chlorobenzene
; hydrogen peroxide
; absorption
; aqueous solution
; Article
; controlled study
; derivatization
; fractionation
; isomer
; kinetics
; light absorption
; limit of detection
; photodegradation
; photolysis
; priority journal
; reaction analysis
; substitution reaction
; chemistry
; fractionation
; kinetics
; solution and solubility
; water pollutant
; Carbon Isotopes
; Chemical Fractionation
; Chlorobenzenes
; Hydrogen Peroxide
; Hydroxyl Radical
; Kinetics
; Photolysis
; Solutions
; Water Pollutants, Chemical
英文摘要: Substituted chlorobenzenes are the basic substructure of many surface water contaminants. In this study, the isotope fractionation and reaction mechanisms involved during the aqueous direct and indirect photodegradation of CH3-, Cl-, and NO2- substituted chlorobenzenes were investigated in laboratory experiments. Only 4-nitrochlorobenzene showed slow but isotopically fractionating direct photolysis. During indirect photodegradation using UV/H2O2-generated OH radicals, the pseudo first-order reaction rate constants increased in the order of the NO2- < Cl- < CH3- substituted chlorobenzenes. The most pronounced carbon enrichment factors were observed for nitrochlorobenzenes (up to −4.8 ± 0.5‰), whereas the lowest were for chlorotoluenes (≤−1.0 ± 0.1‰). As the substituents became more electron-withdrawing, the activation energy barrier increased, leading to slower reaction rates, and the transition state changed to a more symmetrical or less reactant-like structure, resulting in larger apparent kinetic isotope effects. The results suggest that the rate-determining step in the reaction with OH radicals was the addition of the electrophile to the benzene ring. Even though further research is needed to quantify isotope fractionation during other transformation processes, these results showed evidence that compound specific isotope analysis can be used as a diagnostic tool for the fate of substituted chlorobenzenes in water. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112886
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON M5S 3B1, Canada; Department of Isotope Biogeochemistry, Helmholtz Center for Environmental Research UFZ, Permoserstrasse 15, Leipzig, 04318, Germany; TROPOS Leibniz Institute for Tropospheric Research, Atmospheric Chemistry Department (ACD), Permoserstrasse 15, Leipzig, 04318, Germany; Department of Civil Engineering, University of Toronto, 35 St George street, Toronto, ON M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada; Department of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Jinan, 250353, China
Recommended Citation:
Passeport E.,Zhang N.,Wu L.,et al. Aqueous photodegradation of substituted chlorobenzenes: Kinetics, carbon isotope fractionation, and reaction mechanisms[J]. Water Research,2018-01-01,135