Effect of Solution pH on Photodegradation and Photocatalytic Degradation of Tetracyclines

Comparisons were made between tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) in photodegradation and photocatalytic degradation in solutions different in pH. Results show that under UV light, they followed the order of OTC > CTC > TC in photodegradation rate. However, under UV- TiO₂ photocatalysis, they demonstrated little difference in solutions with pH in the range of 3.0-7.0 . Increasing solution pH facilitated both the photodegradation and photocatalysis degradation of TCs, and NH₄+ ions were generated during these processes.