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Magnetic polymeric matrixces were synthesized from glycidyl methacrylate, N,N′-methylenebis(acrylamide) (MBA), and nanomagnetite particles. The obtained polymers were modified by ethylenediamine (DA) and diethylenetriamine (TA) to produce two amino-magnetic resins named R-DA and R-TA. The recovery of Th(IV) ions from their aqueous solutions by R-DA and R-TA were studied in the pH range 1−4. Maximum adsorption capacity values of 60 and 84 mg/g of Th(IV) ions on R-DA and R-TA, respectively, were obtained at pH 3.5 and 293 K. At a solid/liquid ratio (S/L) of 2 g/L, recovery efficiency values of 86 and 95% were achieved from initial thorium ion concentration of 100 mg/L using R-DA and R-TA, respectively. Adsorption isotherms and kinetic and thermodynamic parameters of the adsorption process were obtained and analyzed. Regeneration of the resins was tested by eluting the loaded Th(IV) ions on the spent resins using 0.2 M HNO 3 followed by washing with dilute NaOH.

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A high-energy ball milling of magnetite nanoparticles with amino-phosphonic functionalized poly(glycidyl methacrylate) polymer is used for manufacturing a highly efficient magnetic sorbent for U(VI) sorption from aqueous solutions. The Uranyl ions were adsorbed through the binding with amine and phosphonic groups as confirmed by Fourier Transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The maximum sorption capacity (up to 270 mg U g À1) occurred at pH ¼ 3e4; Langmuir isotherm well describes the sorption process. Small-size particles allow achieving fast uptake (within z90 min of contact); and the kinetic profiles are modeled by the pseudo-second order rate equation. Uranium is successfully desorbed from loaded sorbent using 0.25 M NaHCO 3 solution: Sorbent can be recycled with minimal decrease in sorption and desorption efficiency for at least 6 cycles. The sorbent is efficiently used for U(VI) recovery from the acidic leachates of U-bearing ores (after precipitation pre-treatment). Sorption capacity approaches 190 mg U g À1 despite the presence of high concentrations of Fe and Si: the sorbent has a marked preference for U(VI) (confirmed by distribution ratios and selectivity coefficients).

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