Kinetics of the Chlorate-Sulfite Reaction

Gleason, E. H.; Mino, G.; Thomas, William

doi:10.1021/j150550a015

Cited by 17 publications

(6 citation statements)

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“…In comparison of chlorite/sulfite and bromite/sulfite reaction mechanisms, it is known that the reactions of hypochlorous acid and hypobromous acid with sulfite occur through halogen−sulfur intermediates. 1c,1e, Others have studied the kinetics and mechanisms of bromate/S(IV) reaction , and chlorate/S(IV) reaction. − The reaction rates of these halates increase as [SO 3 ] T becomes more protonated. Despite favorable thermodynamics (eqs 48 and 49), , bromate and chlorate show virtually no reaction with SO 3 2- .…”

Section: Resultsmentioning

confidence: 99%

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Kinetics and Mechanisms of S(IV) Reductions of Bromite and Chlorite Ions

et al. 2002

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The reaction of bromite with aqueous S(IV) is first order in both reactants and is general-acid catalyzed. The reaction half-lives vary from 5 ms (p[H+] 5.9) to 210 s (p[H+] 13.1) for 0.7 mM excess S(IV) at 25 degrees C. The proposed mechanism includes a rapid reaction (k(1) = 3.0 x 10(7) M(-1) s(-1)) between BrO(2)(-) and SO(3)(2-) to form a steady-state intermediate, (O(2)BrSO(3))(3-). General acids assist the removal of an oxide ion from (O(2)BrSO(3))(3-) to form OBrSO(3)(-), which hydrolyzes rapidly to give OBr(-) and SO(4)(2-). Subsequent fast reactions between HOBr/OBr(-) and SO(3)(2-) give Br(-) and SO(4)(2-) as final products. In contrast, the chlorite reactions with S(IV) are 5-6 orders of magnitude slower. These reactions are specific-acid, not general-acid, catalyzed. In the proposed mechanism, ClO(2)(-) and SO(3)H(-)/SO(2) react to form (OClOSO(3)H)(2)(-) and (OClOSO(2))(-) intermediates which decompose to form OCl(-) and SO(4)(2-). Subsequent fast reactions between HOCl/OCl(-) and S(IV) give Cl- and SO(4)(2-) as final products. SO(2) is 6 orders of magnitude more reactive than SO(3)H-, where k(5)(SO(2)/ClO(2)(-)) = 6.26 x 10(6) M(-1) s(-1) and k(6)(SO(3)H(-)/ClO(2)(-)) = 5.5 M(-1) s(-1). Direct reaction between ClO(2)(-) and SO(3)(2-) is not observed. The presence or absence of general-acid catalysis leads to the proposal of different connectivities for the initial reactive intermediates, where a Br-S bond forms with BrO(2)(-) and SO(3)(2-), while an O-S bond forms with ClO(2)(-) and SO(3)H-.

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Section: Resultsmentioning

confidence: 99%

“…1c,1e,30 Others have studied the kinetics and mechanisms of bromate/S(IV) reaction 29,31 and chlorate/S(IV) reaction. [32][33][34] The reaction rates of these halates increase as [SO 3 ] T becomes more protonated. Despite favorable thermodynamics (eqs 48 and 49), 10,11 bromate and chlorate show virtually no reaction with SO 3 2-.…”

Section: Lack Of Buffermentioning

confidence: 99%

Kinetics and Mechanisms of S(IV) Reductions of Bromite and Chlorite Ions

et al. 2002

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“…After 2.5 min, typical DMPO–SO 4 •– and DMPO–HO • signals were marked with diamond squares and triangles, respectively (Figure E) . In addition, the signal of HO • was mainly attributed to the nucleophilic substitution reaction between SO 4 •– adducts and H 2 O/OH – . , The presence of the SO 4 •– implied that the free radical reaction probably ended with the acceptance of e aq – by SO 4 •– to produce sulfate . During activation, sulfite in ASS was first activated by a vortex blender to produce highly reactive radicals like SO 3 •– and e aq – .…”

Section: Resultsmentioning

confidence: 97%

Ammonium Sulfite Slurry from Ammonia-Based Desulfurization Activates Water-Soluble Humic Substances from Lignite: Performance, Application, and Mechanism

Zhao,

Chen,

Yao

et al. 2023

J. Agric. Food Chem.

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Both ammonium sulfite slurry (ASS) from ammonia-based desulfurization and lignite are waste materials with low value. In this work, an innovative method was developed by applying ASS in lignite activation to produce water-soluble humic substances (WHSs) with a high bioactivity and economic value. The optimal activation method was to mix lignite and ASS at a 4:1liquid−solid ratio by vortex blender and then oscillate it for 30 min at 25 °C. Compared with that of the unactivated lignite (UAL), the yield of WHSs from activated lignite (AL) increased by 42.72%. WHSs from AL consisted of a large number of aliphatic carbons with low molecular weight and functional groups such as amides, amines, sulfonic acid groups, C−O, and so forth. Moreover, WHSs from AL at lower concentrations (2 mg/L) has a more obvious root-elongation-promoting effect than WHSs from UAL (10 mg/L). Activation experiment with the lignite-related model compounds revealed that ASS caused the breakage of C aliph −O, C aliph −C aliph , and C arom −C aliph linkages between aromatic rings. These findings provide a theoretical basis for the development of green and sustainable technologies for the beneficial reuse of ASS and lignite in agriculture.

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“…Production of bisulfate ions is critical in these solutions because this species can rapidly react with and degrade chlorate ions, producing sulfate and chloride ions along with additional hydrogen ions (Gleason et al 1957, Nixon & Krauskopf 1932):…”

Section: Resultsmentioning

confidence: 99%

Use of Sodium Thiosulfate to Quench Hypochlorite Solutions Prior to Chlorate Analysis

Boal

Patsalis

2017

Journal AWWA

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Sodium thiosulfate is a commonly used quenching agent for sodium hypochlorite and has previously been deemed acceptable when quenching hypochlorite solutions before conducting chlorate analysis. However, using thiosulfate to quench hypochlorite solutions with compositions similar to those produced by electrolytic onsite generation process (OSG; free available chlorine content of 0.8% with a pH range of 8–10) can result in artificially low chlorate measurements. Reactions between thiosulfate and hypochlorite can result in a substantial decrease in pH that in turn causes the production of bisulfite ions from thiosulfate. In turn, these ions react with chlorate ions, resulting in artificially decreased measurements of chlorate in the initial hypochlorite solutions. Malonic acid does not cause a similar effect when used as a hypochlorite quenching agent and should therefore be used in place of thiosulfate when conducting chlorate analysis of hypochlorite solutions produced through electrolytic OSG processes.

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Kinetics of the Chlorate-Sulfite Reaction

Cited by 17 publications

References 0 publications

Kinetics and Mechanisms of S(IV) Reductions of Bromite and Chlorite Ions

Kinetics and Mechanisms of S(IV) Reductions of Bromite and Chlorite Ions

Ammonium Sulfite Slurry from Ammonia-Based Desulfurization Activates Water-Soluble Humic Substances from Lignite: Performance, Application, and Mechanism

Use of Sodium Thiosulfate to Quench Hypochlorite Solutions Prior to Chlorate Analysis

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