Investigation of photocatalytic degradation of doxycycline antibiotic in aqueous solutions using immobilized zinc oxide nanoparticles on glass: influence of operational parameters and kinetic studies

The aim of this study is the investigation of photocatalytic degradation Doxycycline antibiotic in aqueous solution using different ZnO particles (Aldrich nanoparticles, Merck microparticles and synthesized nanoparticles via chemical deposition) immobilized on glass under UV-C light irradiation. Characteristics of the glass plates coated with ZnO particles were investigated by SEM, AFM and XRD technics. The influence of operational parameters (initinal concentration of doxycycline, UV light intensity and pH value) on activity of ZnO photocatalyst and the kinetic of reaction has been investigated. The results showed that ZnO was effective for the degradation of doxycycline from aqueous solutions in the presence of UV-C light. Removal Percent of 75 mg L-1 of doxycycline, in light intensity = 40 W m-2 and pH = 6.5, for 4 h was found 45.2, 48.80 and 52.7% for Aldrich, Merck and synthesized ZnO respectively. Results of mineralization studies also showed a decreasing trend of COD over time. The results showed that the reaction follows pseudo-first-order kinetic.