Degradação de triclosan e 2,8-diclorodibenzeno-p-dioxina via sistema Fe/Nb2O5/UV

Abstract

This study describes the experimental design and optimization of the photocatalytic reaction using catalyst Fe/Nb2O5 immobilized on anginate beads in the degradation of Triclosan and 2.8-dichlorodibenzene-p-dioxin. The techniques employed to characterize the photocatalysts were: Specific surface area, Average pore volume, and average pore diameter, photo-acoustic spectroscopy (PAS), X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR) and zero charge point. The reaction parameters studied were: pH, Catalyst concentration, Catalyst calcination temperature, nominal metallic charge. The results indicated that the immobilized Fe/Nb2O5 catalysts were efficient in the degradation of Triclosan and 2.8-dichlorodibenzene-p-dioxin. The catalysts with nominal metal loading of 1.5% Fe calcined at 873 K showed the highest constant reaction rate and the lowest half-life, 0.069 min-1 and 10.04 min. Tests in different matrices indicated that the photocatalytic reaction using aqueous solution with content Cl- is faster than when compared with the utlrapura water matrix. The 2.8-DCDD generation and its subsequent degradation was carried out in approximately 80 min of reaction. The results presented by the reactions in continuous system were better or equivalent to those presented by the batch system. The parameters studied (wt% Fe and calcination temperature) in Experimental design and optimization were significant for the process.