Jean-Christophe D'Oliveira, Ghassan Al-Sayyed, P. Pichat
Jul 1, 1990
Citations
1
Influential Citations
341
Citations
Quality indicators
Journal
Environmental Science & Technology
Abstract
The photocatalytic degradations of 2-chlorophenol (2CP) and 3-chlorophenol (3CP) in TiO{sub 2} aqueous suspensions at {lambda} > 340 nm have been studied. They are faster than direct photolysis at {lambda} > 290 nm despite the additional number of photons available in this wavelength region and produce lower maximal concentrations of intermediates. Complete mineralization is achieved eventually; however, it requires a much longer time than dechlorination and dearomatization. Effects of radiant flux, wavelength, initial concentrations, and pH are examined. Para hydroxylation is the main pathway, so that 2CP and 3CP both give rise to chlorohydroquinone (CHQ), whereas formation of catechol (CT) is a very minor pathway in the degradation of 2CP. Further hydroxylation of CHQ and CT forms hydroxyhydroquinone, which rapidly decomposes to carboxylic acids and carbonyl compounds not identified yet.