peer-reviewedThe full text of this article will not be available in ULIR until the embargo expires on the 26/8/2019This study investigates the photocatalytic degradation of acetaminophen (Ace) from synthetic
wastewater by individual TiO2, TiO2/SiO2 and/or WO3/TiO2/SiO2 composite under UV-VIS
illumination. To characterize changes in their morphology and crystal structures before and after
treatment, Χ-ray diffraction (ΧRD), Fourier transform infrared spectroscopy (FTIR) , DRS
UV-VIS absorption spectra, Brunaer-Emmer-Teller (BET) and scanning electron microscopy
(SEM) techniques were used. The effects of varying loading ratios of the WO3 on the TiO2/SiO2
composite for Ace degradation were studied. Operating parameters such as initial concentration,
reaction time, dose of photocatalyst and pH were tested. Degradation by-products were also
presented. It is found that the photodegradation performance of the WO3/TiO2/SiO2 composite as
a photocatalyst in this study could be enhanced by optimizing the loading ratio of the WO3.
About 3% (w/w) of WO3/TiO2/SiO2 was found to improve the degradation of Ace from 33% to
95% at the same initial concentration of 5 mg/L. The resulting oxidation by-products included
hydroquinone and 1,4-benzoquinone. Under the same conditions, the result of photocatalytic
degradation by the 3% (w/w) of WO3/TiO2/SiO2 composite was significantly higher (95%) than
that by the individual TiO2/SiO2 (42%) and/or by the TiO2 alone (33%). Under optimized
conditions (1.5 g/L; 3% (w/w) of WO3/TiO2/SiO2 composite; pH 9; 4 h of reaction time), 95% of
Ace removal with an initial concentration of 5 mg/L could be attained. However, the treated
effluents still could not meet the discharge standard of less than 0.2 mg/L set by China’s and US
legislation. This indicates that further subsequent treatment like biological processes is still
necessary for completing the removal of target pollutant from the wastewater samples