Synergistic effect between UV and chlorine (UV/chlorine) on the degradation of carbamazepine: Influence factors and radical species.

Rate constants and other properties are reported for photochemical reactions initiated by laser photolysis (248 nm) of S2O82-(aq) in acidic solutions containing Cl-(aq) at 297 ± 2 K. The absorption spectra of SO4-•(aq) and Cl2-•(aq) are measured and compared to literature values. Equilibrium constants and rate constants involving Cl•(aq), Cl2-•(aq), H2O, SO4-•(aq), and S2O82-(aq) are determined by analyzing the formation and decay of Cl2-•(aq) and SO4-•(aq) in a self-consistent chemical mechanism. For the first time, the anticipated pH dependence is observed unambiguously in the pseudo-first-order decay rate constant of Cl2-•. The rate constants for the reactions Cl•(aq) + Cl2-•(aq) → Cl2(aq) + Cl-(aq) and Cl2-•(aq) + Cl2-•(aq) → Cl2(aq) + 2Cl-(aq) are determined; rate constants for the latter are measured as a function of temperature and ionic strength. In addition, the ionic strength dependence of the reaction SO4-•(aq) + Cl-(aq) → SO42-(aq) + Cl•(aq) is reported. Rate constants for the reactions of Cl•...

Free Radical Reactions Involving Cl•, Cl2-•, and SO4-• in the 248 nm Photolysis of Aqueous Solutions Containing S2O82- and Cl-

https://hal.archives-ouvertes.fr/hal-02592931/document

Degradation of acetic acid with sulfate radical generated by persulfate ions photolysis

Cl• and Cl2•– radicals contribute to the degradation of trace organic contaminants (TrOCs) such as pharmaceutical and personal care products and endocrine-disrupting chemicals. However, little is k...

Rate Constants and Mechanisms of the Reactions of Cl• and Cl2•– with Trace Organic Contaminants

Kinetics and mechanism of sulfate radical- and hydroxyl radical-induced degradation of highly chlorinated pesticide lindane in UV/peroxymonosulfate system

The chlorine atom (Cl˙) has been generated in aqueous solution by reaction of Cl– with SO˙–4 and H2PO˙4, obtained by metal-catalysed decomposition of the appropriate peroxides. E.s.r. experiments in conjunction with a fast-flow method establish that Cl˙ is highly reactive, readily undergoing rapid addition, hydrogen-abstraction and electron-transfer reactions (k≈ 108–109 dm3 mol–1 s–1). The factors which influence the observed selectivity (energetics and polar effects) are discussed.

Wendy J. Peet

Papers

Generation and reactions of the chlorine atom in aqueous solution