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Direct photolysis with W radiation (254 nm) and oxidation with ozone combined with W radiation of three polynuclear aromatic hydrocarbons, fluorene, phenanthrene, and acenaphthene, has been studied. Quantum yields of the direct photolysis of the PAHs determined were 7.5 x mol(photon)-l for fluorene, phenanthrene, and acenaphthene, respectively. Contributions of direct ozonation, direct photolysis, and radical oxidation have also been estimated for the oxidation with ozone combined with W radiation. Fluorene is oxidized by direct photolysis and radical reactions, phenanthrene through direct mechanisms, ozonation, and photolysis, and acenaphthene mainly by direct ozonation.

Multiwalled carbon nanotubes (CNTs) were functionalized with HNO 3 , HNO 3 /H 2 SO 4 , and HNO 3 /Na 2 CO 3 . The preparation of metal supported on mesoporous carbon nanotube catalyst is described. The catalysts were synthesized by impregnation of carbon nanotubes with different metallic precursors (H 2 PtCl 6 ‚6H 2 O, RuCl 3 ‚ H 2 O, and CuCl 2 ‚2H 2 O) followed by reduction. The structures of the CNT modified with HNO 3 , HNO 3 /H 2 -SO 4 , and HNO 3 /Na 2 CO 3 and CNT-supported metal catalysts have been characterized by means of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and nitrogen adsorption/desorption isotherms (BET), and their activity was tested in continuous catalytic wet air oxidation of aniline. For the catalysts prepared with metal precursors, activities were found in the order of Pt/N-CNT > Cu/N-CNT > Ru/N-CNT. The structure of carbon nanotubes supported metal catalyst is responsible for the activity, and the absence of micropores enhances the potential capabilities of carbon nanotubes as support material.

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Degradation of acid orange II (AOII), a dye present in textile industry wastewater, by the heterogeneous Fenton process (HFP) was performed. In order to select an adequate support, heterogeneous Fenton catalysts were prepared using several materials such as carbon nanotubes, carbon nanofibers, activated carbon, hydrotalcite-like materials, mesoporous silica (MCM41), silica, silica xerogel, sepiolite, and zeolite USY, that were tested in the degradation of AOII as the model compound. Color, total organic carbon, chemical oxygen demand removal, and toxicity were studied in the process. The best catalyst was iron supported on sepiolite. The best performing catalytic material was used to investigate the influence of the presence of carbonate ions, pH, and reuse of catalyst. Also, a real textile wastewater was successfully treated with this catalyst.

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