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International Journal of Photoenergy
Volume 2008, Article ID 497895, 9 pages
http://dx.doi.org/10.1155/2008/497895
Research Article

Photocatalytic Degradation of Polynitrophenols on Various Commercial Suspended or Deposited Titania Catalysts Using Artificial and Solar Light

1Equipe de Catalyse et Environnement, URECAP (99/UR/11-20) Ecole Nationale d'Ingénieurs de Gabès, Faculté des Sciences de Gabès, Campus Universitaire, 6072 Gabès, Tunisia
2Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), (UMR CNRS5256), Université de Lyon, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex, France

Received 26 June 2007; Revised 10 October 2007; Accepted 27 January 2008

Academic Editor: Leonardo Palmisano

Copyright © 2008 Hinda Lachheb et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Phenol (PH) and three polynitrophenols (4-nitrophenol (PNP), 2,4-dinitrophenol (DNP), 2,4,6-trinitrophenol (TNP)) were photocatalytically degraded by using titania under either artificial or solar light. These four reactions were chosen as test reactions to compare the efficiencies of two suspended commercial titania photocatalysts (Degussa P-25 and Millennium PC-500). It appears that P-25 has a higher initial efficiency in all nitrophenol disappearance reactions. However, for the overall degradation rate, measured by the chemical oxygen demand (COD) disappearance, the performance of PC-500 was similar to that of P25. This was attributed to a favorable textural effect since PC-500 has a much higher surface area which facilitates the readsorption of intermediates. PC-500 was subsequently supported on a special photoinert paper provided by Ahlstrom Company (38-Pont Evèque, France). The influence of the silica binder used for sticking titania particles on the paper fibers was put in evidence as an inhibitor of the coulombic adsorption of anionic species, especially 2,4,6-trinitrophenol, because of the low pzc of silica. Once validated, this supported photocatalyst was introduced in an autonomous solar pilot photoreactor identical to the several prototypes built in the European AQUACAT program. It was demonstrated that the purification of water could be efficiently obtained in a larger scale without any final tedious filtration.