Degradation and Loss of Antibacterial Activity of Commercial Amoxicillin with TiO2/WO3-Assisted Solar Photocatalysis

Abstract

In this study, a TiO 2 catalyst, modified with tungsten oxide (WO 3), was synthesized to reduce its bandgap energy (E g) and to improve its photocatalytic performance. For the catalyst evaluation, the effect of the calcination temperature on the solar photocatalytic degradation was analyzed. The experimental runs were carried out in a CPC (compound parabolic collector) pilot-scale solar reactor, following a multilevel factorial experimental design, which allowed analysis of the effect of the calcination temperature, the initial concentration of amoxicillin, and the catalyst load on the amoxicillin removal. The most favorable calcination temperature for the catalyst performance, concerning the removal of amoxicillin, was 700 • C; because it was the only sample that showed the rutile phase in its crystalline structure. Regarding the loss of the antibiotic activity, the inhibition tests showed that the treated solution of amoxicillin exhibited lower antibacterial activity. The highest amoxicillin removal achieved in these experiments was 64.4% with 100 ppm of amoxicillin concentration, 700 • C of calcination temperature, and 0.1 g L −1 of catalyst load. Nonetheless, the modified TiO 2 /WO 3 underperformed compared to the commercial TiO 2 P25, due to its low specific surface and the particles sintering during the sol-gel synthesis.

Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

“…Such findings were quite similar to other studies employing •OH based processes in the degradation of DCF ( [33,34]), thus implying the important role of formed ROS, primarily •OH, in the case of TiO 2 /WO 3 solar driven photocatalysis as well. Arce-Sarria et al [35] studied the performance of TiO 2 /WO 3 composite for the degradation of another pharmaceutical, Amoxicillin (AMX), in pilot scale reactor, where they achieved 64.4% degradation. Besides "pure" TiO 2 /WO 3 composite, several authors studied the performance of its enriched analogues (Table 1).…”

Oxidative Dehydrogenation of Liquefied Petroleum Gas on Copper, Zinc and Iron Oxide Impregnated on MFI Zeolite Assisted by Electric Power

“…The band gaps for different samples can be calculated by plotting [F(R ∞ )hν] 0.5 − hν. The energy band gap (E g ) was obtained by extrapolating slope of the graph [59]. Fermi level was measured with the insertion of two ends of each catalyst, at different temperatures, in a thermally insulated reservoir containing water baths, cold-water baths, or dry ice-alcohol mixtures.…”

Visible-light activation of TiO2 by dye-sensitization for degradation of pharmaceutical compounds

“…11,12 Usually TiO 2 is doped with N, Fe, S and oxides in order to improve its photocatalytic activity under visible radiation; another technique implemented is the sensitization with dyes which has been widely used in the field of solar cells and the production of hydrogen. [13][14][15][16][17] The dye-sensitization process is a technique used to expand the active spectral range of photocatalysts; it has been applied for degradation of chlorophenol, hydrazine, pesticides, phenol and benzyl alcohol. Transition metal based dyes are the best compounds to achieve good electron transfer to the semiconductor, but are expensive and not environment friendly, hence in the sensitization process organic dyes can be used.…”