Photodegradation of Pyridine in a Fluidized Bed Photocatalytic Reactor Using Pt-ZnO Supported on Al₂O₃ as a Catalyst

The degradation of pyridine, considered one of the most polluting heterocycles used in industries, was performed. A fluidized bed photocatalytic reactor (FBR) with the cata-lyst Pt-ZnO/Al₂O₃ synthesized by precipitation and wet impregnation was used for its removal. FTIR, XRD, and SEM characterization were performed on the catalyst. The analyses confirmed the hexagonal structure of ZnO (average crystal size: 53.18 nm), the successful incorporation of Pt (increase to 57.21 nm), and a nano-rods morphology in Pt-ZnO favoring the photocatalytic activity. The kinetics followed the pseu-do-first-order model (R² > 0.95), obtaining a value of k1 = 1.943 × 10-3 min-1 (reaction constant) y k2 =1.527× 10-3 L/mg (absorption constant), reaching pyridine removal of 57.7% at conditions (pH 4, 160 ppm pyridine, 100 g catalyst), validating the efficiency of the RFL to improve mass transfer and catalytic exposure. With the results obtained, it was demonstrated that the Pt-ZnO/Al₂O₃ catalyst possesses high stability and poten-tial for the treatment of industrial wastewater contaminated with N-heterocycles.