Photodegradation of taste and odor compounds in water in the presence of immobilized TiO2-SiO2 photocatalysts

Sudheera Yaparatne; Carl P Tripp; Aria Amirbahman

doi:10.1016/j.jhazmat.2017.12.029

Photodegradation of taste and odor compounds in water in the presence of immobilized TiO₂-SiO₂ photocatalysts

J Hazard Mater. 2018 Mar 15:346:208-217. doi: 10.1016/j.jhazmat.2017.12.029. Epub 2017 Dec 17.

Authors

Sudheera Yaparatne¹, Carl P Tripp², Aria Amirbahman³

Affiliations

¹ Department of Chemistry, University of Maine, Orono, ME, 04469, USA.
² Department of Chemistry, University of Maine, Orono, ME, 04469, USA; Laboratory for Surface Science and Technology (LASST), University of Maine, Orono, ME, 04469, USA.
³ Department of Civil and Environmental Engineering, University of Maine, Orono, ME, 04469, USA. Electronic address: ariaa@maine.edu.

PMID: 29275110
DOI: 10.1016/j.jhazmat.2017.12.029

Abstract

Disinfection by ultraviolet (UV) radiation is a growing trend in public water treatment systems because of its effectiveness with respect to inactivation of protozoa and other pathogenic microorganisms. However, removal of different classes of organic compounds, including taste and odor compounds in water is not effective with UV irradiation. In this study, a novel TiO₂-based immobilized photocatalyst is developed to enhance the UV photodegradation of two of the major taste and odor compounds, 2-methylisoborneol (MIB) and Geosmin (GSM) in water. Evonik (formerly Degussa) P-25 powder-modified TiO₂ was immobilized on glass slides using TiO₂-SiO₂ sol-gel mixture as the binder and calcined at 500 °C. Several catalyst films with different Si amounts were synthesized and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL) and scanning electron microscopy (SEM). Photocatalytic degradation of MIB and GSM was investigated by irradiating aqueous solutions under UV-A light (350 nm). Generation of hydroxyl radicals (OH) was also assessed to evaluate the activity of the photocatalyst films. Catalyst films with surface ratios of Ti:Si ≈6 showed similar degradations rates but better robustness compared to immobilized P25 films.

Keywords: 2-Methylisoborneol (MIB); Geosmin (GSM); Immobilized photocatalyst; P-25 modified TiO(2)-SiO(2); UV.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't