Adsorption of uranium ions from aqueous solution by amine-group functionalized magnetic Fe3O4 nanoparticle

The magnetic Fe3O4 nanoparticle was functionalized by covalently grafting amine group with (3-aminopropyl) trimethoxy silane, and the Fe3O4-NH2 nanoparticle and the Fe3O4 nanoparticle were characterized by Fourier transform infrared, and X-ray diffraction. And the results indicated the amine-group was immobilized successfully on the surface of Fe3O4. The adsorption behavior of uranium from aqueous solution by the Fe3O4 nanoparticle and the Fe3O4-NH2 nanoparticle was investigated using batch experiments. The pH of initial aqueous solution at 5.0 and 6.0 were in favour of adsorption of uranium, and the adsorption percentage of uranium by the Fe3O4 nanoparticle and the Fe3O4-NH2 nanoparticle were 81.2 and 95.6 %, respectively. In addition, the adsorption of uranium ions could be well-described by the Langmuir, Freundlich isotherms and pseudo-second kinetic models. The monolayer adsorption maximum capacity of the Fe3O4 nanoparticle and the Fe3O4-NH2 nanoparticle were 85.35 and 268.49 mg/g at 298.15 K, respectively, which indicate the adsorption capacity the Fe3O4 nanoparticle was improved by amine functionalization. (author)