RESUMEN
Developing efficient adsorbents with radiation stability for uranium removal from nuclear wastewater is greatly important for resource sustainability and environmental safety in manufacturing nuclear fuel. A novel adsorbent of hydrous titanium oxide-immobilized collagen fibers (HTO/CFs) with good radiation stability for UO22+ removal was developed. Results showed that the adsorption capacity of HTO/CFs for UO22+ was 1.379 mmol g-1 at 303 K and pH 5.0 when the initial concentration of UO22+ was 2.5 mmol L-1. Moreover, HTO/CFs showed high selectivity for U(VI) in bilateral mixed solution including UO22+ with another coexisting ion, such as Cl-, NO3-, Zn2+, and Mg2+. The adsorption behavior of UO22+ from radioactive wastewater on HTO/CF column was also investigated, and the breakthrough point was approximately 250 BV (bed volume). Notably, the HTO/CFs column can be rapidly regenerated by using only 4.0 BV of 0.1 mol L-1 HNO3 solution. The regenerated HTO/CFs column exhibited slight change in the breakthrough curve, suggesting its excellent reapplication ability. Furthermore, after irradiation under 60Co γ-ray at total doses of 10-350 kGy, HTO/CFs still preserved fibrous morphology and adsorption capacity, indicating significant radiation stability. These results demonstrate that HTO/CFs are industrial scalable adsorbents for the adsorptive recovery of uranium.