The mass production of antibiotics for use in various cases such as medical use, animal medicine and agriculture has caused the direct and indirect entry of these pollutants into the environment and risks such as environmental pollution and the creation of antibiotic resistance in the human body. Therefore, today much attention has been paid to the removal of antibiotics from different aquatic environments. In this research, a bismuth ferrite-graphene oxide composite was synthesized to improve the properties of bismuth ferrite to remove the antibiotic tetracycline under UV light irradiation. For this purpose, the alkaline hydrothermal method was used to synthesize bismuth ferrite and the modified Homer method was used to prepare graphene oxide. After that, the characteristics of the prepared samples were eva‎luated using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis diffuse reflectance spectra (DRS), Fourier infrared spectroscopy transform (FT-IR), vibrating sample magnetometer (VSM), surface area measurement analysis (BET) ,and X-ray energy diffraction spectroscopy (EDX) were performed, which showed that the composite was well formed. In the following, preliminary tests were carried out to determine the range of effective pH parameters, the amount of composite and the concentration of tetracycline. After that, using Design Expert software and Central Composite Design (CCD) response surface method, parameters effective in tetracycline removal including pH, photocatalyst concentration and tetracycline concentration were optimized. In order to investigate the interaction between the parameters, the response surface diagram and the contour were used. The results of experimental and predicted values were in good agreement (R2=0.9892, experimental R2=0.9794). Also, the analysis of the obtained data showed that the kinetics of the photocatalytic process followed the quadratic equation and Freundlich adsorption isotherm model. These results showed the high removal efficiency (98.8%) of bismuth ferrite-graphene oxide composite in the degradation of tetracycline antibiotics from aqueous environments. Also, the optimal values of each parameter were eva‎luated on real wastewater containing tetracycline, which resulted in 90% removal efficiency. Therefore, it can be concluded that the model is valid and the CCD method is suitable for optimizing the effective parameters in the process of tetracycline removal.

مسعود طاهريون , رقيه حيران

ناصر طالب بيدختي , مسعود طاهريون