DOI: 10.1016/j.watres.2018.10.081
Scopus记录号: 2-s2.0-85056227695
论文题名: Kinetics studies and mechanistic considerations on the reactions of superoxide radical ions with dissolved organic matter
作者: Ma J. ; Zhou H. ; Yan S. ; Song W.
刊名: Water Research
ISSN: 431354
出版年: 2019
起始页码: 56
结束页码: 64
语种: 英语
英文关键词: Dissolved organic matters
; Kinetic studies
; Reaction mechanism
; Superoxide radical ion
Scopus关键词: Activation energy
; Biogeochemistry
; Biological materials
; Decay (organic)
; Dissolution
; Free radical reactions
; Ions
; Ketones
; Kinetics
; pH effects
; Sodium Borohydride
; Apparent activation energy
; Chemiluminescent analysis
; Dissolved organic matters
; Environmental conditions
; Kinetic study
; Reaction mechanism
; Superoxide radical
; Superoxide radical ions
; Rate constants
; dissolved organic matter
; fulvic acid
; ketone
; quinone derivative
; reactive oxygen metabolite
; sea water
; singlet oxygen
; sodium borohydride
; superoxide
; surface water
; activation energy
; aquatic environment
; catalysis
; catalyst
; chemical reaction
; dissolved organic matter
; environmental conditions
; pH
; radical
; reaction kinetics
; reactive oxygen species
; reduction
; temperature effect
; aquatic environment
; Article
; chemical reaction kinetics
; China
; priority journal
; rate constant
; reaction analysis
; river
; solar radiation
; temperature
英文摘要: Superoxide ion (O2 •−) is one of the short lived reactive oxygen species (ROS) formed in aquatic environments. The reactions of O2 •− with the model dissolved organic matter (DOM) were studied using a chemiluminescent analysis method under relevant environmental conditions. The reaction of O2 •− with DOM produced reduced DOM (DOM•−) by fast one-electron-transfer in the initial stage. This process resulted an initial “loss” in the O2 •− decay kinetics. DOM•− is unstable which will continue react with O2 •− generating H2O2 to complete a catalytic dismutation cycle. Based on analyzing the observed pseudo-first order O2 •− decay rates (kpseudo), the quasi-steady-state concentration of DOM•− is found to be equal to the initial loss of O2 •−. Thus, the rate constant for DOM•− with HO2 •/O2 •− is derived to be (1.1–1.9) × 106 M−1 s−1 in the temperature range of 7.8–41.4 °C. Meanwhile, the apparent rate constant for DOM with O2 •− in a flow cell during a short time (2.25 s) is measured as (1.5–3.3) × 103 MC −1 s−1 in the temperature range of 8.2–38.6 °C. These temperature dependent O2 •− reaction rate constants present an apparent activation energy of (19.6 ± 2.9) kJ molC −1 for DOM, while that of DOM•− (12.5 ± 3.5 kJ mol−1) is lower. For the pseudo-first order decay rate of O2 •−, the catalyzed-dismutation by metal components ranges from 13 to 23%; the contribution by aromatic ketones of DOM is estimated to be 10–13% by using NaBH4 reduction method. The residual contribution might mainly occur at the quinone-like groups, which contributed 64%–77% to the total dismutation. The pH effects on the apparent catalytic rate constants dominate the reaction of O2 •− with DOM. The present work suggests that DOM is an important sink for O2 •− in aquatic environments. Furthermore, we proposed that the reaction of O2 •− with DOM could be a potential source of DOM•− in natural water. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122171
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200080, China
Recommended Citation:
Ma J.,Zhou H.,Yan S.,et al. Kinetics studies and mechanistic considerations on the reactions of superoxide radical ions with dissolved organic matter[J]. Water Research,2019-01-01