Sorption of europium on zirconium oxide from aqueous solutions

Sorption of europium on zirconium oxide has been studied as a function of shaking time, concentration and nature of electrolyte. The effect of initial europium concentration and the amount of adsorbent has been investigated in the range from 6.6 * 10-10 to 6.6 * 10-8 mol * dm-3 and between 10 to 200 mg of the oxide. Maximum sorption (>99.8%) from pH 10 buffer and low sorption (<3%) was observed from 0.01 mol * dm-3 nitric or perchloric acid solution. Citrate, sulfate, EDTA and carbonate reduced the sorption significantly. Under optimal conditions Ag(I), Cs(I), Tc(VII), Sb(V), Cu(II), Nd(III), Fe(III), and especially Nd and Fe showed low distribution coefficients. The data followed both Dubinin-Radushkevich and Langmuir-type isotherms. The mean free energy of sorption was evaluated to be 10.1 kJ mol-1 and the sorption capacity was found to be 22.2 mmol g-1, using the Dubinin-Radushkevich isotherm. (author) 28 refs.; 6 figs.; 4 tabs