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Comparison of Ozone and Hydroxyl Radical-Induced Oxidation of Chlorinated Hydrocarbons in Water |
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| Authors: | Susan J Masten Jürg Hoigné |
| Abstract: | The efficiency of ozonation and advanced oxidation processes such as ozone/UV, ozone/H2O2 and H2O2/UV was assessed for chlorinated hydrocarbons using a closed batch-type system. 1,1-Dichloropropene (DCPE), trichloroethylene (TCE), 1-chloropentane (CPA), and 1,2-dichloroethane (DCA) were used as model compounds. The direct reaction between substrates and ozone predominated at lower pH, which resulted in the efficient oxidation of the olefin, DCPE. At higher pH, ozonation resulted in more efficient oxidation of the chlorinated alkanes, with a corresponding decrease in the efficiency of DCPE oxidation. Consistent results were observed for ozone/H2O2 and ozone/UV treatment. Due to slow UV-induced decomposition of H2O2, the process using H2O2/UV (254 nm) resulted in very slow oxidation of all four compounds. The total ozone requirement to achieve a given degree of elimination (to 37% of the original concentration), δ0.37, was used to assess the combined effects of the direct and indirect reactions for different types of waters. |
| Keywords: | Ozone Advanced Oxidation Processes Chlorinated Solvents Chlorinated Olefins Chlorinated Alkanes Hydroxyl Radical Reactions Ozone/UV Ozone/Hydrogen Peroxide Ozonation Efficiency Ozone: Reaction-Rate Constants Micropollutants Hydrogen Peroxide/UV 1 1-Dichloropropene Trichloroethylene 1-Chloropentene 1 2-Dichloroethane |