The Staged Photocatalytic Reactor in the Removal of Acetaminophen: Aspects of Adsorption and Photocatalysis

Abstract

The efficiency of a staged photocatalytic reactor prototype was evaluated on a semi-pilot scale with the removal of acetaminophen, for which anatase particles were synthesized by Sol-Gel and impregnated on rectangular plates of clay. X-ray diffraction and Energy Dispersive X-ray Fluorescence patterns show that the final composite is made up of Al₂O₃ (14 %), SiO₂ (41 %), CaO (3 %) TiO₂ (34 %), and Fe₂O₃ (7 %). The impregnation method favors the dispersion of Anatase on the surface of the adsorbent. TiO₂-Anatase/Clay, classified as a macro-porous solid with H3-type hysteresis loops by N₂ physisorption. Adsorption processes are improved when using TiO₂-Anatase/Clay compared to using TiO₂-Anatase. The external mass transfer has a greater influence on the removal rate. The dimensionless parameters of the Biot number indicate there are no limitations due to the diffusive effect on the interior of the particle. The evaluation of the kinetic data under the Langmuir-Hinshelwood equation shows a decrease in efficiency as the initial concentration increases. The acetaminophen molecule shows destabilization in the structure of the aromatic ring with a visible decrease in the signals of this functional group evaluated by High-Performance Liquid Chromatography and Raman Spectroscopy.