Résumé

The applicability of ozonation to mitigate taste and odor problems in drinking water was investigated. Second-order rate constants of eleven taste and odor compounds with ozone and hydroxyl radicals were determined under laboratory conditions. Measured rate constants for the reaction with hydroxyl radicals are between 3 x 10(9) and 10(10) M(-1)s(-1) and for ozone: k(beta-cyclocitral) = 3890 +/- 140 M(-1)s(-1); k(geosmin) = 0.10 +/- 0.03 M(-1)s(-1); k(3-hexen-1-ol) = 5.4 +/- 0.5 x 10(5) M(-1)s(-1); k(beta-ionone) = 1.6 +/- 0.13 x 10(5) M(-1)s(-1); k(2-isopropyl-3-methoxypyrazine) = 50 +/- 3 M(-1)s(-1); k(2-methylisoborneol) = 0.35 +/- 0.06 M(-1)s(-1); k(2,6-nonadienal) = 8.7 +/- 0.4 x 10(5) M(-1)s(-1); k(1-penten-3-one) = 5.9 +/- 0.1 x 10(4) M(-1)s(-1); k(2,6-di-tert-butyl-4-methylphenol (BHT)) = 7.4 +/- 0.2 x 10(4) M(-1)s(-1); k(2,4,6-tribromoanisole) = 0.02 +/- 0.01 M(-1)s(-1); k(2,4,6-trichloroanisole) = 0.06 +/- 0.01 M(-1)s(-1). Experiments conducted in natural waters showed that the removal efficiency during ozonation can be reliably predicted with the determined second-order rate constants. Ozonation is a powerful tool capable of oxidizing most of the taste and odor compounds to more than 50% under typical drinking water treatment conditions. For ozone-resistant taste and odor compounds, the application of advanced oxidation processes may be appropriate.

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