Ozone decomposition in concentrated aqueous solutions of salts

Ершов, Б. Г.; Panich, N. M.; Селиверстов, А. Ф.; Belyaeva, M. P.

doi:10.1134/s1070427208040319

Cited by 11 publications

(10 citation statements)

References 8 publications

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“…The correctness of expression is confirmed by the results of independent experiments on the kinetics of ozone decomposition in solutions of chlorides, which are shown in Figure and also can be found in the literature. − The data in Figure are consistent with the notion that ozone decay occurs in two parallel processes. First, it is the spontaneous decomposition reaction with brutto-equation O 3 → 3 / 2 O 2 , whose apparent rate constant k 1 = 1.55 × 10 –3 s –1 , and second, the reaction of ozone with chloride ion, with the rate constant k 2 .…”

Section: Resultssupporting

confidence: 83%

Solubility of Ozone and Kinetics of Its Decomposition in Aqueous Chloride Solutions

Леванов

Isaikina

Gasanova

et al. 2018

Ind. Eng. Chem. Res.

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Solubility of ozone and kinetics of its decomposition in aqueous solutions of NaCl and NaCl + HCl have been investigated as functions of solution composition, electrolyte concentration, and temperature. A methodology has been developed, in which dissolved O3 concentration was measured by a direct spectrophotometric technique by absorbance at 260 nm, with ozone decomposition in the sample and the presence of other substances also absorbing light at 260 nm being taken into account. For solutions with concentrations of Cl– 0–2 M and H+ 0–0.5 M, the solubility coefficient (L O3) and Henry’s law constant of ozone (K H) have been determined in the temperature range 20–40 °C, as well as the kinetic order and apparent rate constants of O3 decomposition (at 20 ± 1 °C). Formulas have been obtained for calculating L O3 and K H for various values of temperature and electrolyte concentration. An equation is presented for computing the rate constant of ozone reaction with chloride ion in aqueous solution via the mechanism of oxygen atom transfer as a function of temperature and concentration of H+ ions.

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Section: Resultssupporting

confidence: 83%

Solubility of Ozone and Kinetics of Its Decomposition in Aqueous Chloride Solutions

Леванов

Isaikina

Gasanova

et al. 2018

Ind. Eng. Chem. Res.

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“…If we relate the constant of the decomposition of ozone found in the works men tioned above to the concentration of chloride ions, we obtain the upper limit values for the rate constant of the noncatalytic reaction between О 3 and Cl -. These estimates are in agreement with the following data [5]: k < 3 × 10 -3 l/(mol s) (рН 6, 20°С) [6]; k < 6 × 10 -3 l/(mol s) (pH 6, 20°С) [7].…”

supporting

confidence: 86%

“…For the same reason, only the upper limit value of the rate constant was determined in [5] for the non catalytic reaction between О 3 and Cl -(aq) at 23°С, k < 3 × 10 -3 l/(mol s) (pH 2). In [6,7], the kinetics of the decomposition of ozone in an aqueous solution containing chloride ions was studied using the same method as in [5]. If we relate the constant of the decomposition of ozone found in the works men tioned above to the concentration of chloride ions, we obtain the upper limit values for the rate constant of the noncatalytic reaction between О 3 and Cl -.…”

mentioning

confidence: 99%

Primary stage of the reaction between ozone and chloride ions in aqueous solution: Oxidation of chloride ions with ozone through the mechanism of oxygen atom transfer

Леванов

Antipenko

Лунин

2012

Russ. J. Phys. Chem.

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519Studying how ozone reacts with chloride ions in aqueous solutions is of immediate interest. This reac tion is possible in various manufacturing processes (e.g., water conditioning and purification) involving the use of ozone and in which the presence of Cl -ions is possible. Due to the presence of ozone in the Earth's atmosphere and the great abundance of chloride ions in nature, the reaction between О 3 and Cl -can con siderably affect the environment. The probability of the reaction between these two components must be taken into account when using ozonized saline solu tion in medicine.The question of the nature of the primary stage in the complex reaction between О 3 and Cl -(aq) is of great importance. A mechanism in which the oxida tion of chloride ions with ozone occurs via the transfer of an oxygen atom from the О 3 molecule to the Cl -ion has been recognized in all works devoted to studying the reaction between О 3 and Cl -(aq) since 1949. In 2010, however, a new mechanism for this reaction was proposed: it was claimed that the oxidation of chloride atoms is accompanied by the transfer of an electron from the Cl -ion to the О 3 molecule [2, 3] (see also [4]). The purpose of this work is to clarify via which mechanism the primary stage of the reaction between О 3 and Cl -(aq) actually proceeds.One feature of the complex reaction between О 3 and Cl -(aq) is that its primary stage is a slow process. At the same time, the substances produced during the primary stage are much more reactive than chloride ions and enter into rapid secondary reactions that lead to the formation of the final products. As a result, indi vidual primary reactions (without secondary reac tions) is virtually inaccessible to experimental studies. Consequently, any conclusions as to the nature of the primary stage should be based on information about the final products and the kinetic features of the com plex reaction between О 3 and Cl -(aq) as a whole.The kinetics of the reaction between О 3 and Cl -(aq) in an acid aqueous solution were studied for the first time in [1]. The reaction was found to be catalyzed by Н + ions, and the rate constants were determined to be 0 and 9.5°С. At higher temperatures, determination of the rate constants failed, since the results were dis torted appreciably by the decomposition of ozone. For the same reason, only the upper limit value of the rate constant was determined in [5] for the non catalytic reaction between О 3 and Cl -(aq) at 23°С, k < 3 × 10 -3 l/(mol s) (pH 2). In [6,7], the kinetics of the decomposition of ozone in an aqueous solution containing chloride ions was studied using the same method as in [5]. If we relate the constant of the decomposition of ozone found in the works men tioned above to the concentration of chloride ions, we obtain the upper limit values for the rate constant of the noncatalytic reaction between О 3 and Cl -. These estimates are in agreement with the following data [5]: k < 3 × 10 -3 l/(mol s) (рН 6, 20°С) [6]; k < 6 × 10 -3 l/(mol s) (pH 6, 20°С) [7].The produ...

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“…Gardoni et al [14] k 12 10 7 − s 1 Gardoni et al [14] k 13 × 5 0 10 9 . Gardoni et al [14] k 14 10 7 − s 1 Gardoni et al [14] k 15 × 7 0 10 8 .…”

Section: The Transition State (Ts) and Relative Energiesmentioning

confidence: 99%

“…[8][9][10][11][12] The efficiency of an ozone-based wastewater treatment depends on ozone concentration and is linked to its rate of decomposition. [13] Therefore, it is important to study and clarify the kinetics of ozone decomposition in water.…”

Section: Introductionmentioning

confidence: 99%

Theoretical estimation of the apparent rate constants for ozone decomposition in gas and aqueous phases using ab initio calculations

Esfahani

Visscher

2019

Can J Chem Eng

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An ab initio study, using the coupled cluster calculations (CCSD) method was conducted to investigate the kinetics of the ozone degradation in gas and aqueous phases considering the reaction of ozone with the hydroperoxyl radical. Two potential transition state paths, oxygen and hydrogen transfer, are studied and compared. It was revealed by the ab initio quantum chemical calculations that the calculated overall rate constant in the gas phase differs by approximately an order of magnitude from measured values. However, the calculated selectivity (branching fraction), which was measured directly with isotope studies of hydrogen atom transfer, is almost exactly equal to the experimental value at 298.15 K. The sensitivity analysis showed that adding the reaction between ozone and hydroperoxyl radical to the kinetic model accelerates the decomposition process by more than four times in the aqueous phase (pH = 7–8.5), and for an order of magnitude change in the rate constant of this reaction, the decomposition half‐life changes by 20–45 %. This result might affect our understanding of atmospheric ozone chemistry.

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Ozone decomposition in concentrated aqueous solutions of salts

Cited by 11 publications

References 8 publications

Solubility of Ozone and Kinetics of Its Decomposition in Aqueous Chloride Solutions

Solubility of Ozone and Kinetics of Its Decomposition in Aqueous Chloride Solutions

Primary stage of the reaction between ozone and chloride ions in aqueous solution: Oxidation of chloride ions with ozone through the mechanism of oxygen atom transfer

Theoretical estimation of the apparent rate constants for ozone decomposition in gas and aqueous phases using ab initio calculations

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