Photocatalytic degradation of gentamicin antibiotics using Fe3O4 / SiO2 / TiO2 nanocomposites synthesized in aqueous solutions in the presence of sunlight

The purpose of this work is to study degradative removal of gentamicin antibiotic from aqueous media that a trace amount of it may present a human health risk. To this aim photocatalytic process using a recyclable magnetic titania photo-catalyst was utilized. The Nano-catalyst was synthesized, characterized, and utilized to remove gentamicin antibiotic. The process modeling and optimization were performed by a second order polynomial model using design of experiment software. According to the model prediction, the process can remove gentamicin antibiotic up to 94.7% in the optimum condition. The introduced optimum conditions were; initial pH = 6.9, [gentamicin] = 20 ppm, [Catalyst] = 195 mg, and time = 63 min. Mineralization of the gentamicin was also investigated such that in the optimum condition 51.3% mineralization efficiency was obtained in optimum condition. Kinetic study results showed that the data was well fitted by pseudo first order kinetic model. Also, the effect of sulfate and chloride ions as radical scavenger on removal efficiency was assessed and process efficiency was reduced by using chloride and sulfate.