WO3–TiO2 based catalysts for the simulated solar radiation assisted photocatalytic ozonation of emerging contaminants in a municipal wastewater treatment plant effluent

Abstract

This work is focused on the use of TiO2–WO3 photocatalysts for the removal of a mixture of emerging contaminants through photocatalytic ozonation using simulated solar light as radiation source. Own-made TiO2–WO3 catalysts with WO3 content around 4wt% were synthesized using P25 and titanate nanotubes as TiO2 starting materials. Photocatalysts were thoroughly characterized by means of ICP–OES, N2 adsorption–desorption isotherms, XRD, TEM, Raman, XPS and DR–UV–Vis spectroscopy. Photocatalytic ozonation using WO3 based titanate nanotubes composite gave place to complete removal of emerging contaminants (caffeine, metoprolol and ibuprofen in a Municipal Wastewater Treatment Plant effluent aqueous matrix) in less than 40min with TOC removal up to 64% after 2h. The highest catalytic activity of this material in the reaction under study compared to bare TiO2 is due to several effects such as higher activity under visible light radiation joined to an increase in adsorption capacity of organic compounds and catalytic ozonation ability caused by the presence of WO3.