title: Multi-wavelength spectroscopic and chromatography study on the photocatalytic oxidation of natural organic matter.
abstract: The effect of TiO2 photocatalytic oxidation on the natural organic matter (NOM) properties of two Australian surface waters were quantified using UV-vis spectroscopy, high performance size exclusion chromatography (HPSEC) with a multi-wavelength UV detector, liquid chromatography with organic carbon detector (LC-OCD), and trihalomethane formation potential (THMFP) analyses. Both the UV absorbance at wavelengths greater than 250 nm and dissolved organic carbon (DOC) content decreased significantly with treatment, although complete mineralization of NOM could not be achieved. Multi-wavelength UV detection of HPSEC analysis was shown to be useful to display further changes to NOM composition and molecular weight profiles because the organic molecules was transformed into compounds that absorb weakly at the typical detection wavelength of 250-260 nm. The multi-wavelength HPSEC results also revealed that photocatalytic oxidation yields by-products with a low aromaticity and low molecular weight. The LC-OCD chromatograms indicated that low molecular acids and neutral compounds remained after photocatalytic oxidation. Those groups of compounds did not seem to contribute significantly to the formation of trihalomethanes.
authors.affiliation: ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Sciences and Engineering, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Sanly
authors.initials: S
authors.lastname: Liu
authors.forename: May
authors.initials: M
authors.lastname: Lim
authors.forename: Rolando
authors.initials: R
authors.lastname: Fabris
authors.forename: Christopher W K
authors.initials: CW
authors.lastname: Chow
authors.forename: Mary
authors.initials: M
authors.lastname: Drikas
authors.forename: Gregory
authors.initials: G
authors.lastname: Korshin
authors.forename: Rose
authors.initials: R
authors.lastname: Amal
mesh_terms: D001315:Australia; D002845:Chromatography; D009930:Organic Chemicals; D010084:Oxidation-Reduction; D010777:Photochemistry; D013057:Spectrum Analysis; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D014867:Water; C009495:titanium dioxide; D014025:Titanium