Photodegradation of 2- and 3-chlorophenol in TiO sub 2 aqueous suspensions

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00077a007· OSTI ID:5465280

D'Oliveira, J; Al-Sayyed, G; Pichat, P ^[1]

---

1. Ecole Centrale de Lyon, Ecully (France)

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.

• OSTI ID: 5465280
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 24:7; ISSN ESTHA; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
AQUEOUS SOLUTIONS
AROMATICS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DISPERSIONS
FLUX DENSITY
HYDROXY COMPOUNDS
MIXTURES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PHENOLS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
POLLUTANTS
RADIANT FLUX DENSITY
SOLUTIONS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS