Determination of hydroxyl radical rate constants in a continuous flow system using competition kinetics

Kwon, Bum Gun; Ryu, S . K .; Yoon, Jeyong

doi:10.1016/j.jiec.2009.09.004

Cited by 28 publications

(20 citation statements)

References 24 publications

(42 reference statements)

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“…These authors used p-nitrosodimethylaniline (PDNA) as a reference system with the reference rate constant from Buxton. [3] However, almost all measured rates in the paper of Kwon [49] are slower than earlier data summarized in the review of Buxton [3] by approximately a factor of two. This might indicate a systematic problem in their approach.…”

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confidence: 66%

“…Amines are currently heavily discussed in atmospheric chemistry due to their abundance in marine [44,45] and small, newly formed [46] particles. Furthermore, the reactions of OH with some derivatives such as nitrosamines and nitramines have been newly investigated by Mezyk et al [47] Aromatics A number of new rate constants is available for mostly deactivated aromatic benzene, phenol and benzoic acid derivatives from the studies of Monod et al, [28] Zona et al, [48] Kwon et al, [49] Einschlag et al, [50] Elovitz et al, [51] Makarov et al, [52] Elovitz et al, [51] and Geeta et al [53] All reported data do refer to room temperature rate constants only with 23 new determinations and 12 remeasurements, and for four major differences in the rate constants are observed (Table 7).…”

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confidence: 99%

“…Kwon et al [49] introduced a continuous-flow system for the measurement of aqueous-phase OH radical rate constants using competition kinetic method. These authors used p-nitrosodimethylaniline (PDNA) as a reference system with the reference rate constant from Buxton.…”

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confidence: 99%

“…This might indicate a systematic problem in their approach. For the reaction of OH with benzoate, an average rate constant of k = 5.9 10 9 m À1 s À1 is recommended as the average of the available rate constants with the exception of the Kwon [49] measurement, which is lower by about a factor of two as the only one of eight independent determinations.…”

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confidence: 99%

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Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

et al. 2010

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The most important radicals which need to be considered for the description of chemical conversion processes in tropospheric aqueous systems are the hydroxyl radical (OH), the nitrate radical (NO(3)) and sulphur-containing radicals such as the sulphate radical (SO(4)(-)). For each of the three radicals their generation and their properties are discussed first in the corresponding sections. The main focus herein is to summarize newly published aqueous-phase kinetic data on OH, NO(3) and SO(4)(-) radical reactions relevant for the description of multiphase tropospheric chemistry. The data compilation builds up on earlier datasets published in the literature. Since the last review in 2003 (H. Herrmann, Chem. Rev. 2003, 103, 4691-4716) more than hundred new rate constants are available from literature. In case of larger discrepancies between novel and already published rate constants the available kinetic data for these reactions are discussed and recommendations are provided when possible. As many OH kinetic data are obtained by means of the thiocyanate (SCN(-)) system in competition kinetic measurements of OH radical reactions this system is reviewed in a subchapter of this review. Available rate constants for the reaction sequence following the reaction of OH+SCN(-) are summarized. Newly published data since 2003 have been considered and averaged rate constants are calculated. Applying competition kinetics measurements usually the formation of the radical anion (SCN)(2)(-) is monitored directly by absorption measurements. Within this subchapter available absorption spectra of the (SCN)(2)(-) radical anion from the last five decades are presented. Based on these spectra an averaged (SCN)(2)(-) spectrum was calculated. In the last years different estimation methods for aqueous phase kinetic data of radical reactions have been developed and published. Such methods are often essential to estimate kinetic data which are not accessible from the literature. Approaches for rate constant prediction include empirical correlations as well as structure activity relationships (SAR) either with or without the usage of quantum chemical descriptors. Recently published estimation methods for OH, NO(3) and SO(4)(-) radical reactions in aqueous solution are finally summarized, compared and discussed.

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Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

et al. 2010

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“…This was confirmed by measuring the COD value of the KHP solutions. KHP is often used as a standard COD analyte because it is completely oxidized by standard COD analysis; 1 mg of KHP normally has a theoretical COD value of 1.177 mg. Fronk, 1987;Gunten, 2003;Rosenfeldt et al, 2006;Kwon et al, 2009). Similar approach has been used to the treatment of industrial wastewaters using H 2 O 2 alone (Zak, 2008).…”

Section: Error In Livestock Wastewater Cod Values Due To H 2 Omentioning

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Hydrogen peroxide interference in chemical oxygen demand during ozone based advanced oxidation of anaerobically digested livestock wastewater

Lee

Kim

et al. 2011

Int. J. Environ. Sci. Technol.

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It is known that hydrogen peroxide interferes with chemical oxygen demand analysis by consuming oxidation agents such as potassium dichromate, thus leading to overestimation of the chemical oxygen demand measurements. The objective of the study was to investigate the effects of hydrogen peroxide interference and to determine true chemical oxygen demand values on interpreting treatment performance during ozone-based advanced oxidation of livestock wastewater in which hydrogen peroxide concentration and chemical oxygen demand values are dynamically changing. According to the chemical oxygen demand monitoring data, chemical oxygen demand values were always higher than the initial chemical oxygen demand load when hydrogen peroxide was involved and the treatment performance with ozone alone or ozone/ultraviolet was better than with coupled hydrogen peroxide. The extent of overestimation was proportional to the remaining hydrogen peroxide concentration and the average overestimation ratio in livestock wastewater was in the range of 0.50~0.58 mg per 1 mg of hydrogen peroxide, depending upon the quality of the wastewater treated. True chemical oxygen demand values were estimated by correlating the extent of overestimation with the remaining hydrogen peroxide concentration during treatment. The extent of overestimation decreased to zero gradually as the amount of hydrogen peroxide also approached zero as oxidation proceeded. The corrected chemical oxygen demand values indicated underlying tendency of oxidation, which could not be seen in the original chemical oxygen demand monitoring data. Application of ozone/hydrogen peroxide was more efficient for reducing chemical oxygen demand than ozone alone, as was ozone/hydrogen peroxide/ultraviolet compared to ozone/ultraviolet. When coupled with ozone, ultraviolet irradiation was more efficient than hydrogen peroxide for decreasing chemical oxygen demand during treatment of livestock wastewater.

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Electro-oxidation of ceftazidime in real municipal wastewater using PbO2–Ce and SnO2–Sb electrodes: influence of electrolyte and degradation pathway

et al. 2020

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Determination of hydroxyl radical rate constants in a continuous flow system using competition kinetics

Cited by 28 publications

References 24 publications

Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

Tropospheric Aqueous‐Phase Free‐Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools

Hydrogen peroxide interference in chemical oxygen demand during ozone based advanced oxidation of anaerobically digested livestock wastewater

Electro-oxidation of ceftazidime in real municipal wastewater using PbO2–Ce and SnO2–Sb electrodes: influence of electrolyte and degradation pathway

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