Mailhot G, Asif A, Bolte M
Laboratoire de Photochimie Moléculaire et Macromoléculaire, Unité Mixte de Recherche CNRS, Université Blaise Pascal, Aubiere, France.
Chemosphere. 2000 Aug;41(3):363-70. doi: 10.1016/s0045-6535(99)00434-8.
The Fe(III)-photoinduced degradation of 4-dodecylbenzenesulphonate (DBS) in aqueous solution was investigated. The mixing of DBS (1 mm) and Fe(III) (1 mm) solutions immediately led to the formation of a precipitate that contained DBS and monomeric Fe(OH)2+, the predominant Fe(III) species. Both species were also present in the supernatant. Irradiation of the supernatant solution resulted in a photoredox process that yielded Fe(II) and *OH radicals. The disappearance of DBS was shown to involve only attack by *OH radicals; the quantum yield of DBS disappearance is similar to the quantum yield of *OH radical formation. A wavelength effect was also observed; the rate of DBS disappearance was higher for shorter wavelength irradiation. Five photoproducts, all containing the benzene sulphonate group, were identified. *OH radicals preferentially abstract hydrogen from the carbon in the alpha position of the aromatic ring. The results show that the Fe(III)-photoinduced degradation of DBS could be used as an alternative method for polluted water treatment.
