Radiolysis of sodium p-cumenesulfonate in aqueous solution

An insight into the effective advanced oxidation process for treatment of simulated textile dye waste water

“…22,31 SO 4 c À can also produce benzyl radical by H-abstraction reaction from the alkyl chain of the SDBS. 28,32,33 The bi-molecular rate constants for the reaction of SO 4 c À with SDBS was calculated as 3.8 Â 10 8 dm 3 mol À1 s À1 from the decay of SO 4 c À at 450 nm (at pH 10.0) and it is similar to the value reported $3.6 Â 10 8 dm 3 mol À1 s À1 . 28 The H-abstraction reaction of SO 4 c À from the alkyl chain was veried by monitoring the decay of SO 4 c À radical with the reaction of SDS in N 2 purged 5.0 Â 10 À4 mol dm À3 SDS containing 2.0 Â 10 À2 mol dm À3 K 2 S 2 O 8 and 2.0 Â 10 À2 mol dm À3 tert-butanol at pH 10.0 by employing 14 Gy per pulse.…”

“…The peak around at 270-290 nm is attributed to the benzyl type radical and broad peak at 300-350 nm correspond to the formation of OH-adduct with the benzene ring. 22,29 All of the transient species absorbing at 290, 320 and 325-340 nm decayed faster in presence of 4 : 1 (v/v) mixture of N 2 O and O 2 and it suggests that the produced transient species had carbon centered radicals. The decay constant of the transient reacting with O 2 could not be determined because of the interference of the formation signal of the peroxy type radical with the decay signal of the reacting transient.…”

“…Apart from these above phenomena direct H-atom abstraction may also take place from the alkyl chain of SDBS by cOH. 29 The bi-molecular rate constant of the reaction between cOH and SDBS was calculated as 1.8 Â 10 9 dm 3 mol À1 s À1 (at pH 10.0), which is similar to the value reported $10 10 dm 3 mol À1 s À1 (at pH 7) by Méndez-Díaz et al 28 The similar types of transient absorption peaks were observed at 290, 320 and 330 nm in the reaction of SDBS with SO 4 c À (Fig. 4b).…”

Rate constants of dichloride radical anion reactions with molecules of environmental interest in aqueous solution: a review

“…Benzenesulfonic acid practically does not react with Cl 2 •due to the presence of the strong electron withdrawing sulfonate group (Hasegawa and Neta 1978). Osiewala et al (2013) published an unexpectedly high value for the molecule which has a cumene group in para position (pcumenesulfonate, 9.4 × 10 9 M -1 s -1 ). Cl 2 •is suggested to react by electron transfer from aromatic ring and also by abstracting the tertiary H-atom of the cumene group.…”

“…There are exceptions, e.g., certain dye cations (methylene blue, toluidine blue, safranine T, Kishore et al 1989 ; Mahadevan et al 1990 ; Guha et al 1992 ) have strong absorbances out of this range which allow direct observation of product build-up. Transient products were identified only in few cases (e.g., Dwibedy et al 2005 ; Osiewala et al 2013 ; Caregnato et al 2013 ). In mechanistic studies, instead of Cl 2 •- , sometimes azide radical (N 3 • ) is used, this radical does not have light absorption in the 300-500 nm range (Buxton and Janovský 1976 ; Hug 1981 ) .…”