Study on High-Efficiency Photocatalytic Degradation of Oxytetracycline Based on a Spiral Microchannel Reactor

In this work, a spiral microchannel reactor was used to study the photocatalytic degradation process of oxytetracycline (OTC) in a titanium dioxide (TiO 2 ) slurry system. The influence of parameters such as residence time, TiO 2 dosage, OTC concentration, light intensity, and concentration of added ions (NO 3 –, SO 4 2–, Ca 2+, Fe 3+ ) on OTC removal was systematically investigated, and the degradation stability of OTC in the microreactor was evaluated. The results show that under the best experimental conditions, the degradation rate of OTC can reach 99.33%, the initial stage apparent reaction rate constant is 7.7124 min –1, and the space–time yield is 142.79 m 3 pollutants/(m 3 reactor day). In addition, the results prove the high efficiency and stability of OTC degradation in the microreactor. OTC can be efficiently degraded under high TiO 2 dosage, high initial OTC concentration, and low light intensity, which demonstrates the outstanding advantages of spiral microchannels for OTC degradation in slurry systems. This study has a guiding significance for the efficient photocatalytic degradation of tetracycline antibiotics in slurry systems.