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Abstract
Two magnetic nanohybrid oxides are prepared by two different techniques. The first one CeO₂-TiO₂-Fe₂O₃ which is synthesized by copreciptation method however, CeO₂-TiFe₂O₄ is prepared by solvothermal method. The prepared nanosorbents are characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, BET surface area, vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). The obtained nanosorbents are applied as magnetic adsorbent for removal of uranium ions from waste aqueous solutions using batch experiments. The effect of variant parameters effect on uranium adsorption e.g. pH of aqueous solution, adsorbent dose, shaking time, initial concentration and temperature are investigated. The adsorptions processes on two magnetic nanoadsorbents are well described by and Freundlich and Hasely for CeO₂- TiO₂-Fe₂O₃ and CeO₂-TiFe₂O₄, respectively. Kinetic studies indicated that the adsorption process correspond well to pseudo-second-order model. The thermodynamic parameters show that the adsorption of U(VI) onto CeO2-TiO₂-Fe₂O₃and CeO₂-TiFe₃O₄ was a spontaneous and endothermic nature of process. The highest values of uranium desorption from CeO₂-TiO₂-Fe2O₃ is achieved using 0.1 M HCl as the desorbing agent which is regenerated and recycled for at least five cycles. On other hand, CeO₂-TiFe₂O₄ can be regenerated for at least six cycles by using 0.1M HNO₃. The obtained results indicate that the prepared nanoadsrbents act as a powerful promising sorbents for the efficient removal of U(VI) from aqueous solutions. Finally, the removal of uranium ions by two different magnetic nanohybrid oxides was carried out under the same conditions. The maximum adsorption capacities at pH 6.00 and T 25 ⁰C were 439.88 and 476.2for CeO₂-TiO₂-Fe2O₃ and CeO₂-TiFe₂O₄, respectively