Rate constants for direct reactions of ozone with several drinking water contaminants
Abstract
Rate constants for the direct reactions of ozone with 45 potential organic drinking water contaminants, including solvents, haloalkanes, esters, aromatics and pesticides (such as alachlor, aldicarb, atrazine, carbofuran, 2,4-dichlorophenoxyacetic acid, endrin, glyphosate, etc.), have been measured in water in the presence of hydroxyl radical scavengers to minimize interfering radical chain reactions. The data demonstrate, again, the electrophilic nature of the ozonation reaction. In addition, for complex molecules, steric factors are important in limiting reactivity. The zwitterionic compound glyphosate exhibits a complex pH dependence that is explained by the inductive effect of side-chain protonation on the basicity of the amine reaction center. Rate constants for ozone consumption differ from those for compound consumption by an amount presumably equal to the reaction stoichiometry.
- Publication:
-
Water Research
- Pub Date:
- 1991
- DOI:
- 10.1016/0043-1354(91)90155-J
- Bibcode:
- 1991WatRe..25..761D
- Keywords:
-
- ozonation;
- rate constants;
- kinetics;
- pesticides;
- solvents;
- p K <SUB>a</SUB>;
- water treatment;
- oxidation of organics