Abstract
The Fe{sup II}/H{sub 2}O{sub 2} system (Fenton reagent) has often been studied for its uses in the field of organic pollutants in aqueous medium. More recently, some works on environmental chemistry have shown that the Fenton reactions can also be included in the oxidation of organic or inorganic compounds and have an influence on the oxidizing species (O{sub 2}, H{sub 2}O{sub 2}, OH{sup .}) in aerosols and natural waters. In this work, the kinetics of oxidation of Fe{sup II} and of organic compounds (atrazine, 1,2,4-tri-chloro-benzene) in dilute aqueous solution by Fe{sup II}/H{sub 2}O{sub 2} have then been investigated. Experiments were carried out at 25 degrees Celsius, at initial pH between 1 and 8, and in presence of an excess of Fe{sup II} ([Fe{sup II}]{sub 0}{>=}2[H{sub 2}O{sub 2}]{sub 0}). Data obtained at pH{<=}3 showed that the rates of oxidation of Fe{sup II} and of organic compounds were predicted well by a kinetic model based on the Fe{sup II}/H{sub 2}O{sub 2} mechanism proposed by Barb et al. in 1951. The following values were found for the kinetic rate constants for the reaction of OH{sup .} with atrazine (molecular form: k=6.2*10{sup 9} L mol{sup -1} s{sup -1}; protonated form: k=1.2*10{sup 9} L mol{sup
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Gallard, H;
Laat, J de;
Legube, B
[1]
- Centre National de la Recherche Scientifique (CNRS), 86 - Poitiers (France). Laboratoire de Chimie de l`Eau et de l`Environnement
Citation Formats
Gallard, H, Laat, J de, and Legube, B.
Effect of pH on the oxidation rate of organic compounds by Fe{sup II}/H{sub 2}O{sub 2}. Mechanisms and simulation; Influence du pH sur la vitesse d`oxydation de composes organiques par Fe{sup II}/H{sub 2}O{sub 2}. Mecanismes reactionnels et modelisation.
France: N. p.,
1998.
Web.
doi:10.1039/a708335a.
Gallard, H, Laat, J de, & Legube, B.
Effect of pH on the oxidation rate of organic compounds by Fe{sup II}/H{sub 2}O{sub 2}. Mechanisms and simulation; Influence du pH sur la vitesse d`oxydation de composes organiques par Fe{sup II}/H{sub 2}O{sub 2}. Mecanismes reactionnels et modelisation.
France.
https://doi.org/10.1039/a708335a
Gallard, H, Laat, J de, and Legube, B.
1998.
"Effect of pH on the oxidation rate of organic compounds by Fe{sup II}/H{sub 2}O{sub 2}. Mechanisms and simulation; Influence du pH sur la vitesse d`oxydation de composes organiques par Fe{sup II}/H{sub 2}O{sub 2}. Mecanismes reactionnels et modelisation."
France.
https://doi.org/10.1039/a708335a.
@misc{etde_296236,
title = {Effect of pH on the oxidation rate of organic compounds by Fe{sup II}/H{sub 2}O{sub 2}. Mechanisms and simulation; Influence du pH sur la vitesse d`oxydation de composes organiques par Fe{sup II}/H{sub 2}O{sub 2}. Mecanismes reactionnels et modelisation}
author = {Gallard, H, Laat, J de, and Legube, B}
abstractNote = {The Fe{sup II}/H{sub 2}O{sub 2} system (Fenton reagent) has often been studied for its uses in the field of organic pollutants in aqueous medium. More recently, some works on environmental chemistry have shown that the Fenton reactions can also be included in the oxidation of organic or inorganic compounds and have an influence on the oxidizing species (O{sub 2}, H{sub 2}O{sub 2}, OH{sup .}) in aerosols and natural waters. In this work, the kinetics of oxidation of Fe{sup II} and of organic compounds (atrazine, 1,2,4-tri-chloro-benzene) in dilute aqueous solution by Fe{sup II}/H{sub 2}O{sub 2} have then been investigated. Experiments were carried out at 25 degrees Celsius, at initial pH between 1 and 8, and in presence of an excess of Fe{sup II} ([Fe{sup II}]{sub 0}{>=}2[H{sub 2}O{sub 2}]{sub 0}). Data obtained at pH{<=}3 showed that the rates of oxidation of Fe{sup II} and of organic compounds were predicted well by a kinetic model based on the Fe{sup II}/H{sub 2}O{sub 2} mechanism proposed by Barb et al. in 1951. The following values were found for the kinetic rate constants for the reaction of OH{sup .} with atrazine (molecular form: k=6.2*10{sup 9} L mol{sup -1} s{sup -1}; protonated form: k=1.2*10{sup 9} L mol{sup -1} s{sup -1}) and 1,2,4-tri-chloro-benzene (k=6.2*10{sup 9} L mol{sup -1} s{sup -1}). At pH > 4 and in the absence of dissolved oxygen, the kinetic model was found to overestimate the rate of oxidation of both atrazine and 1,2,4-tri-chloro-benzene. These data suggest that the reaction of H{sub 2}O{sub 2} with Fe{sup II} probably goes through the formation of an intermediate. This intermediate leads to the formation of OH{sup .} radicals and Fe{sup III} (major route under acidic pH) or leads to the formation of another intermediate which may react with Fe{sup II} to produce Fe{sup III} without formation of OH{sup .}. (authors) 15 refs.}
doi = {10.1039/a708335a}
journal = []
issue = {3}
volume = {22}
journal type = {AC}
place = {France}
year = {1998}
month = {Mar}
}
title = {Effect of pH on the oxidation rate of organic compounds by Fe{sup II}/H{sub 2}O{sub 2}. Mechanisms and simulation; Influence du pH sur la vitesse d`oxydation de composes organiques par Fe{sup II}/H{sub 2}O{sub 2}. Mecanismes reactionnels et modelisation}
author = {Gallard, H, Laat, J de, and Legube, B}
abstractNote = {The Fe{sup II}/H{sub 2}O{sub 2} system (Fenton reagent) has often been studied for its uses in the field of organic pollutants in aqueous medium. More recently, some works on environmental chemistry have shown that the Fenton reactions can also be included in the oxidation of organic or inorganic compounds and have an influence on the oxidizing species (O{sub 2}, H{sub 2}O{sub 2}, OH{sup .}) in aerosols and natural waters. In this work, the kinetics of oxidation of Fe{sup II} and of organic compounds (atrazine, 1,2,4-tri-chloro-benzene) in dilute aqueous solution by Fe{sup II}/H{sub 2}O{sub 2} have then been investigated. Experiments were carried out at 25 degrees Celsius, at initial pH between 1 and 8, and in presence of an excess of Fe{sup II} ([Fe{sup II}]{sub 0}{>=}2[H{sub 2}O{sub 2}]{sub 0}). Data obtained at pH{<=}3 showed that the rates of oxidation of Fe{sup II} and of organic compounds were predicted well by a kinetic model based on the Fe{sup II}/H{sub 2}O{sub 2} mechanism proposed by Barb et al. in 1951. The following values were found for the kinetic rate constants for the reaction of OH{sup .} with atrazine (molecular form: k=6.2*10{sup 9} L mol{sup -1} s{sup -1}; protonated form: k=1.2*10{sup 9} L mol{sup -1} s{sup -1}) and 1,2,4-tri-chloro-benzene (k=6.2*10{sup 9} L mol{sup -1} s{sup -1}). At pH > 4 and in the absence of dissolved oxygen, the kinetic model was found to overestimate the rate of oxidation of both atrazine and 1,2,4-tri-chloro-benzene. These data suggest that the reaction of H{sub 2}O{sub 2} with Fe{sup II} probably goes through the formation of an intermediate. This intermediate leads to the formation of OH{sup .} radicals and Fe{sup III} (major route under acidic pH) or leads to the formation of another intermediate which may react with Fe{sup II} to produce Fe{sup III} without formation of OH{sup .}. (authors) 15 refs.}
doi = {10.1039/a708335a}
journal = []
issue = {3}
volume = {22}
journal type = {AC}
place = {France}
year = {1998}
month = {Mar}
}