Use of Modified Cellulose Sorbents for the Extraction of Th(IV) Ions From Chloride Solutions

The recovery of thorium from acidic chloride medium with amine grafted cellulose resins was studied. Mesoporous polymers were modified with ethylenediamine (R1) and diethylenetriamine (R2) after grafting with glycidyl methacrylate. The sorbents obtained were characterized by Fourier transform IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, and surface area measurements. Modified cellulose resins showed high capacity with relative fast kinetics in batch sorption of Th(IV) ions from chloride aqueous solutions. The maximum uptake capacity for Th(IV) ions on R1 and R2 was found to be 80 and 94.6 mg g–1 at pH 3.0 at 25°C within 45 min. The adsorption reaction followed the pseudo-second-order model. The data were fitted well by Langmuir isotherm. The mean adsorption energy calculated using DR isotherm showed that the adsorption followed the chemisorption mechanism. The process was exothermic. The performance of the sorbents in the recovery of Th(IV) ions from a standard rock sample and a granite sample from Gattar area, Egypt, was studied. Desorption was performed using different acids. The maximum Th(IV) desorption, 95 ± 2.8%, was reached with 1 M HNO3.