Removal of UO22+ from aqueous solution using halloysite nanotube-Fe3O4 composite

Halloysite nanotubes (HNTs) were modified with Fe3O4 to form novel magnetic HNTs-Fe3O4 composites, and the composites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The as-obtained results indicated that Fe3O4 nanoparticles were successfully installed on the surface of HNTs. The adsorption of UO22+ on HNTs-Fe3O4 was investigated as a function of solid content, contact time, pH, ionic strength and temperature by batch experiments. The consequences revealed that the adsorption of UO22+ onto HNTs-Fe3O4 was strongly dependent on pH and ionic strength. Equilibrium data fitted well with the Langmuir isotherm. The experimental results demonstrated that the adsorbents with HNTs-Fe3O4 had the largest adsorption capacity of 88.32mg/g for UO22+.