Evaluation of photocatalytic degradation of a commercial humic acid in water using a simulated solar UV irradiation and monitoring the changes by size exclusion chromatography Available to Purchase

Much research has been undertaken on the photocatalytic degradation of humic substances with titanium dioxide using commercial humic acids (HA), which are extracts from either peat or coal. Most of the research has been focused on the changes in dissolved organic carbon (DOC) and UV₂₅₄ absorption. These parameters only give a general assessment. This work studies the changes in the physical and structural properties of a commercial humic acid by size exclusion chromatography with DOC and UV₂₅₄ absorption detection (SEC-DOC, SEC-UV₂₅₄), and the evolution of halogenated organic compounds (AOX) and trihalomethanes (THMs) during the photocatalytic degradation with simulated solar UV irradiation and Degussa P-25 TiO₂. These changes are compared with those reported for natural organic matter (NOM). The photodegradation of commercial HA and NOM proceeds in a similar and sequential manner, initially with the preferential adsorption of larger molecules, then the degradation of these larger molecular size fractions and proceeding towards smaller molecular size fractions, while decreasing THMs and AOX formation potential.