Rate constants of reactions of bromine with phenols in aqueous solution
| Autor: | B. Legube, Jean-Philippe Croué, Fabien Pellizzari, Hervé Gallard |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Environmental Engineering
Kinetics Inorganic chemistry chemistry.chemical_element Photochemistry Water Purification Reaction rate Ammonia chemistry.chemical_compound Reaction rate constant Phenols Chlorine Water Movements Water Pollutants Waste Management and Disposal Water Science and Technology Civil and Structural Engineering Aqueous solution Bromine Chemistry Ecological Modeling Halogenation Hydrogen-Ion Concentration Pollution |
| Zdroj: | Water research. 37(12) |
| ISSN: | 0043-1354 |
| Popis: | The kinetics of bromination of six ortho- and para-substituted phenols was investigated between pH 5 and pH 12 in aqueous solution. Kinetics was followed with a continuous-flow reactor previously validated by studying the fast reaction between chlorine and ammonia. The overall reaction rate between bromine and phenols is controlled by the reaction of HOBr with the phenoxide ion between pH 6 and pH 10. The reaction of HOBr with the undissociated phenols and the reaction of BrO(-) with the phenoxide ions become only significant for pH6 and pH10, respectively. The second-order rate constants for the reaction of HOBr with phenoxide ions vary between 1.4(+/-0.1)x10(3) and 2.1(+/-0.5)x10(8)M(-1)s(-1) for 2,4,6-trichlorophenol and 4-methylphenol, respectively. Hammett-type correlation was obtained for the reaction of HOBr with the phenoxide ions (log(k)=8.0-3.33 x Sigmasigma) and was compared with Hammett-type correlations of HOCl and HOI. The reaction rate of bromine with phenol-like organic compounds was estimated to be about 10(3)-fold higher than with chlorine and 10(3)-fold lower than with ozone in drinking water treatment conditions. |
| Databáze: | OpenAIRE |
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