Investigation of variables affecting UV-LED photocatalytic degradation of antibiotics ciprofloxacin and sulfamethoxazole

In this study, photolytic and photocatalytic degradation of two antibiotics in ultra-pure water were analyzed. A lab-scale cylindrical reactor had its inner walls impregnated with TiO2 nanofilm for the photocatalytic experiments. In the first step, an optimized photoreactor design was chosen based on the degradation of ciprofloxacin (CIP) under UV-A. The impact of controlled periodic illumination (CPI) on kinetic rates and energy expenses was also studied. In the second step, degradation of both ciprofloxacin and sulfamethoxazole (SMX) were analyzed at different wavelengths (UV-A and UV-C) using the photoreactor design selected in the first step. Results show the optimization benefits of an appropriate photoreactor and CPI for photocatalysis. Each compound’s reactivity to different degradation pathways plays a major role in the process, so a careful study of the particularities of each system is paramount for lowering energy expenses.