Beaded segments like bi-metallic nano-zero-valent iron-titanium for the fast and efficient adsorption and reduction of U(VI) in aqueous solutions

Nano-scale zero-valent iron (NZVI) is easy to be agglomerated and passivated in the process of U(VI) reduction and fixation. Herein, a facile one-step process for titanium modified beaded segments like nano-zero-valent iron nanoparticles (FTNP) was designed and prepared for U(VI) adsorption-reduction from aqueous solution. The as-prepared NZVI, FTNP were characterized by Fourier transform infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), X-Ray photoelectron spectra (XPS), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and Energy dispersive X-ray spectrum (EDS). Results indicated that the beaded segments like FTNP were successful prepared. Furthermore, the uranium removal performance of FTNP with the effect of adsorption and reduction were investigated and showed excellent adsorption and reducibility for U(VI) from aqueous solution. Batch adsorption for U(VI) shown the U(VI) adsorption capacity of FTNP reached 734.4 mg g(-1) (pH = 5.0). In the Fe-U reaction system, Fe2+ was generated as the primary reducing agent to reduce U(VI) from Fe-0. Therefore, part of U(VI) was removed and reduced to U(IV), while others was precipitation hydrolyzed to schoepite, which also reduced to U(IV) and precipitated. This study may provide a novel and significant method for using nano-zero-valent iron to develop for wastewater decontamination.