Photocatalytic degradation of ceftriaxone in aqueous solutions by immobilized TiO2 and ZnO nanoparticles: Investigating operational parameters

The main objective of this study was to investigate the degradation of ceftriaxone with immobilized tio2 and zno as heterogeneous catalysts. scanning electron microscopy (sem) and atomic force microscopy (afm) was used to characterize the surface of both catalysts. photodegradation was compared using direct photolysis (uv alone),tio2/uv,and zno/uv processes in a photoreactor with high-pressure mercury lamp irradiation. special attention was given to the influence of the initial concentration of ceftriaxone,initial ph and light intensity (li),on photodegradation processes. the results showed that photodegradation involving uv/tio2 process was more effective than that involving uv/zno process. either of the experiments was performed in the same operational conditions of c0,light intensity,desired value of ph for both catalysts,and the apparent rate constant (kapp) appears to be about 0.022 min-1 for uv/tio2 process (ph = 5) and about 0.0081 min-1 for uv/zno process (ph = 8). for both systems,the photodegradation of ceftriaxone followed the pseudo-firstorder kinetics.