Reactivity of selected volatile organic compounds (VOCs) toward the sulfate radical (SO₄⁻)

Abstract

Rate constants for a series of alcohols, ethers, and esters toward the sulfate radical (SO 4 Ϫ ) have been directly determined using a laser photolysis set-up in which the radical was produced by the photodissociation of peroxodisulfate anions. The sulfate radical concentration was monitored by following its optical absorption by means of time resolved spectroscopy techniques. At room temperature the following rate constants were derived: methanol ((1.); and dimethyl succinate (CH 3 OC(O)CH 2 CH 2 C(O)OCH 3 ) ((1.37 Ϯ 0.08) ϫ 10 6 M Ϫ1 s Ϫ1 ) where the errors represent 2. For the two latter species, we also measured the temperature dependence of the corresponding rate constants. A correlation of these kinetics with the bond dissociation energy is also presented and discussed.

Direct α‐Arylation of Ethers through the Combination of Photoredox‐Mediated CH Functionalization and the Minisci Reaction

“…While we cannot definitively rule out the latter possibility, we favor the proposed HAT pathway based on mechanistic evidence from the literature. Studies of the reaction of SO 4 •− and ethers via transient absorption spectroscopy, [18a] kinetic isotope effects, [18b] and correlation between BDEs and reaction rates [18c] are consistent with HAT as the operative mechanism. In the related case of alcohols, both ESR experiments [18b] and Minisci-type trapping reactions [13a] suggest that hydrogen abstraction, not SET–deprotonation, is the dominant pathway in the sulfate radical anion-mediated generation of α-oxyalkyl radicals.…”

Sulfate radical-based water treatment in presence of chloride: Formation of chlorate, inter-conversion of sulfate radicals into hydroxyl radicals and influence of bicarbonate

“…Highly reactive sulfate radicals (SO 4 À ) are principally capable of oxidizing pollutants such as trichloroethene (Liang et al, 2008), tert-butylmethylether (George et al, 2001), chlorinated ethenes (Waldemer et al, 2007), and pharmaceuticals such as endosulfan (Shah et al, 2013) and different derivates of phenol (Anipsitakis et al, 2006;Fang et al, 2013;Lin et al, 2011). Thus, SO 4 À based oxidation is frequently discussed as an alternative oxidative treatment option for pollutant control in water treatment.…”

Removal of sulfanilic acid from wastewater by thermally activated persulfate process: oxidation performance and kinetic modeling

“…When the solution pH became basic, the transformation of into HO • increased. Because HO • exhibits a relatively higher redox potential than that of under alkaline conditions, the degradation rates of SA remained high under alkaline conditions …”