GADOLINIUM SORPTION ON MULTI-WALLED CARBON NANOTUBES

Abstract

Rare earth metals are deemed to be the materials of future due to their numerous applications including medical diagnostics, nuclear facilities, petroleum industry, etc. In this paper, multi-walled carbon nanotubes, which possess unique physicochemical properties, were evaluated as sorbents for lanthanoid gadolinium from aqueous solutions. The pH-dependent sorption behavior of Gd was studied in the pH range from 3 to 11 at room temperature (298 K). Equilibrium data over a range of initial Gd concentrations of 5−50 mg L−1 was analyzed with Langmuir, Freundlich and Redlich-Peterson models. Sorption kinetics was fitted with the pseudo-first-order, the pseudo-second-order and fractional power kinetic models.