الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Magnetite nanoparticles (Fe3O4) and humic acid coated magnetite nanoparticles (Fe3O4/ HA) were prepared by co-precipitation method for uranium, euorpiuum, cerium and molybdenum ions removal from aqueous solution. The success of preparation in nanoscale was confirmed by XRD and TEM. The TEM image shows that the size of Fe3O4 is around 15nm and the presence of humic acid reduces the magnetite aggregation and stabilizes the magnetite suspension. Adsorption studies with respect to various process variables such as contact time, pH and temperature were investigated by the batch technique. The sorption kinetics and isotherms of U(VI), Ce (IV), Eu(III) and Mo(VI) ions on Fe3O4 and Fe3O4/ HA show that the sorption kinetics follow the pseudo-second-order and Langmuir isotherm model for both sorbents. The presence of humic acid enhances the sorption of the investigated elements on magnetite nanoparticles. The thermodynamic parameters (∆Go, ∆Ho and ∆So) were calculated, and the results revealed that the sorption process of U(VI), Ce(IV), Eu(III) and Mo(VI) ions on both Fe3O4 and Fe3O4 / HA are spontaneous, endothermic for Fe3O4 and exothermic for Fe3O4/ HA.