Photocatalytic Degradation of Oxytetracycline in a Wall-Loaded TiO2 Microchannel Reactor

Abstract

In this work, a wall-loaded TiO2 microchannel reactor was employed for the photocatalytic removal of oxytetracycline (OTC) from aqueous solutions, with integrated reactor design, systematic parameter optimization, high space-time yield, and semiempirical modeling as the key innovative focuses of the study. The influence of multiple operational parameters, including catalyst loading amount, pollutant concentration, light intensity, and dopant ion content, on the degradation performance of OTC was thoroughly examined. Moreover, the 180 min operational stability and catalytic efficiency of the system were systematically evaluated. Experimental findings indicated that incorporating polyethylene glycol (PEG) into the dip-coating solution significantly promoted uniform TiO2 film formation without altering its crystalline structure after calcination. Under the optimized reaction conditions, the reactor achieved a removal efficiency of 58.67% within a 1 min residence time, accompanied by an apparent rate constant of 0.8994 min–1 and a space-time yield of 844.24 m3 pollutants·m–3 reactor·day–1. These results provide valuable guidance for designing microreactor systems with immobilized catalysts to enhance the photocatalytic removal efficiency of OTC in wastewater treatment.