Adsorption characteristics of amoxicillin antibiotic on CeO2-coated SiO2 nanomaterials

This study investigated adsorption of beta-lactam antibiotic Amoxicillin (AMX) on a new material of cerium oxide-coated nanosilica (CeO2-coated SiO2). The CeO2-coated SiO2 based on rice husk, was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Adsorption behaviors of AMX on CeO2-coated SiO2 at different pH and ionic strength were thoroughly studied. The highest removal of AMX using CeO2-coated SiO2 reached 99.26 % at pH 4 while the maximum adsorption capacity was found to be greater than 11.0 mg/g. Adsorption isotherms of AMX on CeO2-coated SiO2 at different ionic strength were in accordance with Freundlich model. Adsorption of amphoteric AMX species on CeO2-coated SiO2 increased with a decrease of salt concentration indicating that adsorption was controlled by both electrostatic and non-electrostatic interactions