Nanostructured Magnetic Aluminosilicate for Strontium Radionuclide Sorption from Aqueous Media

Synthesis of a nanostructured magnetic aluminosilicate sorbent for the efficient removal of 90Sr from aqueous media has been investigated. The inorganic sorbent was obtained by co-precipitation followed by hydrothermal treatment to give a composite with nanoparticles of magnetic phase based on Fe3O4 (5–10 nm) uniformly distributed in an amorphous aluminosilicate matrix (in 1 : 3 ratio). Structural studies confirmed mesoporous morphology (specific surface area is 40 m2/g) and thermal stability up to 1000°C. The sorption material displays superparamagnetic properties (18 emu/g), which enable its efficient magnetic separation from purified solution. The maximal capacity toward stable Sr2+ ions is 105 mg/g (Langmuir model), with high distribution coefficients for radionuclides Kd (90Sr) = 2273–2368 mL/g even in the presence of competitive Ca2+ ions (100 mg/L). The sorption material is promising for the purification of liquid radioactive wastes.