Evolution of natural organic matter by size exclusion chromatography during photocatalytic degradation by solvothermal-synthesized titanium dioxide

摘要

This study shows the effect of different titanium dioxides in transforming the structural properties of natural organic matter (NOM) during photocatalytic degradation with a solar UV light simulator. Titanium dioxide (TiO_2) synthesized by the sol-gel method coupled with the solvothermal technique and Degussa P-25 TiO_2 were used. The evolution of NOM degradation was followed by size exclusion chromatography with dissolved organic carbon, ultraviolet and fluorescence detection (SEC-DOC, SEC-UV_(254) and SEC-Fl_(254/450))- For both catalysts, there was a preferential degradation of the larger molecules of NOM into medium and smaller molecular size fractions. However, the synthesized TiO_2 was found to be more efficient than Degussa P-25 TiO_2 for DOC removal, especially UV_(254) absorption and Fl_(254/450) removal.