Composite magnetic sorbents based on magnetic Fe3O4 coated by Zn and Al layered double hydroxide for U(VI) removal from aqueous media.

Composite sorbents based on Fe₃O₄ and Zn-Al-LDH with different weight ratios of magnetic and sorbing phases were obtained by the precipitation method. The optimal weight ratio of Zn/Fe was 16, which resulted in a 62% increase in hydromechanical strength. The maximum sorption exchange capacity towards U(VI) was 268.65 ± 22.22 mg/g. The efficiency of U(VI) adsorption was not affected by the presence of Cl⁻, SO₄²⁻, NO₃⁻ and Na⁺, Ca²⁺. The distribution coefficient in a groundwater model solution was K_d(U(VI) = 0.5–3 × 10⁵ mL/g. The materials possess high exchange capacity and selectivity, which makes them suitable sorbents for U(VI) removal. [ABSTRACT FROM AUTHOR]