Abstract
Simple carbonyl chromophores can be used to facilitate the solar- promoted reductive dehalogenation of halo-organics. Here we describe the kinetics and mechanism of the reductive dehalogenation of carbon tetrachloride (CT) to chloroform (CF) in the presence of aqueous acetone and 2-propanol, which is added as a hydrogen donor. The reaction is rapid in sunlight, stoichiometrically converting 3 mM CT to CF in approximately 2 min. Under typical conditions (0.69 M acetone, 5.7 M 2-propanol, 3 mM CT) using a 75 W Xe lamp, the observed zero-order reaction occurs at a rate of 2.7 x 10- 6 M s-1. The mechanism appears to become first order in CT near the end of the reaction. The zero-order reaction rate increased with both acetone- and 2-propanol concentration and also with absorbed light intensity. Other combinations of carbonyls, alcohols, and halogenated organics are also effective.
Original language | English (US) |
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Pages (from-to) | 1229-1233 |
Number of pages | 5 |
Journal | Environmental Science and Technology |
Volume | 34 |
Issue number | 7 |
DOIs | |
State | Published - Apr 1 2000 |
ASJC Scopus subject areas
- General Chemistry
- Environmental Chemistry