| Popis: |
In recent years, scientific research has faced the numerous problems deriving from the presence of active ingredients in surface and groundwater. Traditional removal methods, such as adsorption and bioremediation, have several disadvantages; thus, in this work, membranes based on cellulose acetate loaded with Fe-N-TiO2, were tested for the photocatalytic degradation of Ceftriaxone Sodium from aqueous solution. The immobilization of the photocatalyst allows to overcome the limits of the photocatalytic process in suspension, which requires expensive and time-consuming post-treatments. Membranes were obtained by supercritical CO2 phase inversion process and were subjected to characterizations such as EDX, TGA, FT-IR, Raman spectroscopy and, subsequently, tested in adsorption tests in the dark and in the presence of visible light, to evaluate their photocatalytic activity. The variations in the concentration of the antibiotic, during the tests conducted, were monitored by HPLC chromatographic analysis. Samples with 10% and 30% by weight of Fe-N-TiO2 demonstrated relatively low adsorption efficiencies of the target contaminant, respectively equal to 22% and 18% in 180 minutes, for reasons related both to the morphology of the samples products, which changes from cellular to finger-like as the photocatalyst load increases, and to the quality of the dispersion. The membrane loaded with 20% by weight of Fe-N-TiO2 allowed a degradation of the model pollutant of 35% in 180 minutes; moreover, the reusability of the membranes was verified. The photocatalytic tests showed that the photocatalytic efficiency was highly correlated to the dispersion of the photocatalyst nanoparticles and to its loading in the polymeric membranes. |
