Efficient Decomposition of Perfluorocarboxylic Acids in Aqueous Suspensions of a TiO2 Photocatalyst with Medium-Pressure Ultraviolet Lamp Irradiation under Atmospheric Pressure / Tsuyoshi Ochiai in Industrial & engineering chemistry research, Vol. 50 N° 19 (Octobre 2011)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 10943–10947 Titre : Efficient Decomposition of Perfluorocarboxylic Acids in Aqueous Suspensions of a TiO2 Photocatalyst with Medium-Pressure Ultraviolet Lamp Irradiation under Atmospheric Pressure Type de document : texte imprimé Auteurs : Tsuyoshi Ochiai, Auteur ; Yuichi Iizuka, Auteur ; Kazuya Nakata, Auteur Année de publication : 2011 Article en page(s) : pp. 10943–10947 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalyst Ultraviolet lamp irradiation Résumé : Decomposition of environmentally persistent perfluorooctanoic acid (PFOA) in aqueous suspensions of a TiO2 photocatalyst, with use of medium-pressure ultraviolet (MPUV) lamp irradiation alone, was examined under atmospheric pressure. Compared to direct photolysis, TiO2 photocatalysis led to efficient PFOA decomposition and production of CO2 and F–. PFOA decomposition followed pseudo-first-order kinetics, with observed rate constants of 1.3 × 10–2 and 8.6 × 10–2 dm3 h–1 in direct photolysis and TiO2 photocatalysis, respectively. The latter (photocatalytic) rate constant is 5–100 times greater than those obtained in other published research on the photocatalytic decomposition of PFOA. In the proposed decomposition pathway, PFOA molecules adsorb onto the TiO2 surface according to adsorption equilibrium in an aqueous suspension and could be easily decomposed by holes and radicals generated by MPUV lamp irradiation. Under the present reaction conditions, a narrow region of TiO2 concentrations around 1.5 wt % showed the maximum extent of PFOA decomposition, CO2 formation, and F– formation. The optimum rate can be attributed to a trade-off between an increase of photon absorption by TiO2 and a decrease in UV penetration below the surface of the TiO2 suspension. In the 1.5 wt % TiO2 photocatalyst concentration, 5 mM PFOA was almost totally decomposed during 4 h of MPUV lamp irradiation under atmospheric pressure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1017496#cor1 [article] Efficient Decomposition of Perfluorocarboxylic Acids in Aqueous Suspensions of a TiO2 Photocatalyst with Medium-Pressure Ultraviolet Lamp Irradiation under Atmospheric Pressure [texte imprimé] / Tsuyoshi Ochiai, Auteur ; Yuichi Iizuka, Auteur ; Kazuya Nakata, Auteur . - 2011 . - pp. 10943–10947. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 10943–10947 Mots-clés : Photocatalyst Ultraviolet lamp irradiation Résumé : Decomposition of environmentally persistent perfluorooctanoic acid (PFOA) in aqueous suspensions of a TiO2 photocatalyst, with use of medium-pressure ultraviolet (MPUV) lamp irradiation alone, was examined under atmospheric pressure. Compared to direct photolysis, TiO2 photocatalysis led to efficient PFOA decomposition and production of CO2 and F–. PFOA decomposition followed pseudo-first-order kinetics, with observed rate constants of 1.3 × 10–2 and 8.6 × 10–2 dm3 h–1 in direct photolysis and TiO2 photocatalysis, respectively. The latter (photocatalytic) rate constant is 5–100 times greater than those obtained in other published research on the photocatalytic decomposition of PFOA. In the proposed decomposition pathway, PFOA molecules adsorb onto the TiO2 surface according to adsorption equilibrium in an aqueous suspension and could be easily decomposed by holes and radicals generated by MPUV lamp irradiation. Under the present reaction conditions, a narrow region of TiO2 concentrations around 1.5 wt % showed the maximum extent of PFOA decomposition, CO2 formation, and F– formation. The optimum rate can be attributed to a trade-off between an increase of photon absorption by TiO2 and a decrease in UV penetration below the surface of the TiO2 suspension. In the 1.5 wt % TiO2 photocatalyst concentration, 5 mM PFOA was almost totally decomposed during 4 h of MPUV lamp irradiation under atmospheric pressure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1017496#cor1

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