TY - JOUR
T1 - A kinetic study of enhancing effect by phenolic compounds on the hydroxyl radical generation during ozonation
AU - Han, Y. H.
AU - Ichikawa, K.
AU - Utsumi, H.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2004
Y1 - 2004
N2 - Ozone decomposition in aqueous solution proceeds through a radical type chain mechanism. These reactions involve the very reactive and catalytic intermediates O2- radical, OH radical, HO2 radical, OH-, H2O2, etc. OH radical is proposed as an important factor in the ozonation of water among them. In the present study, the enhancing effects of several phenolic compounds; phenol, 2-, 3-, 4-monochloro, 2,4-dichloro, 2,4,6-trichlorophenol on OH radical generation were mathematically evaluated using the electron spin resonance (ESR)/spin-trapping technique. OH radical was trapped with a 5,5-dimethyl-1 -pyrroline-N-oxide (DMPO) as a stable adduct, DMPO-OH. The initial velocities of DMPO-OH generation in ozonated water containing phenolic compounds were quantitatively measured using a combined system of ESR spectroscopy with stopped-flow apparatus, which was controlled by homemade software. The initial velocities of DMPO-OH generation increased as a function of the ozone concentration. The relation among ozone concentration, amount of phenolic compounds and the initial velocity (ν0) of DMPO-OH generation was mathematically analyzed and the following equation was obtained, ν 0 (10-6 M/s) = (A′ × [PhOHs (10-9 M)] + 0.0005) exp (60 × [ozone (10-9 M)]). The equation fitted very well with the experimental results, and the correlation coefficient was larger than 0.98.
AB - Ozone decomposition in aqueous solution proceeds through a radical type chain mechanism. These reactions involve the very reactive and catalytic intermediates O2- radical, OH radical, HO2 radical, OH-, H2O2, etc. OH radical is proposed as an important factor in the ozonation of water among them. In the present study, the enhancing effects of several phenolic compounds; phenol, 2-, 3-, 4-monochloro, 2,4-dichloro, 2,4,6-trichlorophenol on OH radical generation were mathematically evaluated using the electron spin resonance (ESR)/spin-trapping technique. OH radical was trapped with a 5,5-dimethyl-1 -pyrroline-N-oxide (DMPO) as a stable adduct, DMPO-OH. The initial velocities of DMPO-OH generation in ozonated water containing phenolic compounds were quantitatively measured using a combined system of ESR spectroscopy with stopped-flow apparatus, which was controlled by homemade software. The initial velocities of DMPO-OH generation increased as a function of the ozone concentration. The relation among ozone concentration, amount of phenolic compounds and the initial velocity (ν0) of DMPO-OH generation was mathematically analyzed and the following equation was obtained, ν 0 (10-6 M/s) = (A′ × [PhOHs (10-9 M)] + 0.0005) exp (60 × [ozone (10-9 M)]). The equation fitted very well with the experimental results, and the correlation coefficient was larger than 0.98.
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U2 - 10.2166/wst.2004.0497
DO - 10.2166/wst.2004.0497
M3 - Article
C2 - 15566192
AN - SCOPUS:8844220473
VL - 50
SP - 97
EP - 102
JO - Water Science and Technology
JF - Water Science and Technology
SN - 0273-1223
IS - 8
ER -