Affinity of neodymium and samarium toward AD10N zeolite

In this study adsorption of neodymium and samarium on AD10N zeolite was exa mined. As a result of the Langmuir adsorption isotherms of both elements, t he maximum concentrations of the lanthanides in the zeolite phase are 0.000 34 (mol/g) and 0.00031 (mol/g), respectively, for Nd and Sm. After inspecti on of the adsorption changes with the pH. we found that adsorption of the l anthanides results from ion exchange (pH = 3.2-3.8 for Nd, pH = 3.5-4.5 for Sm), hydrolysis (pH = 3.8-8 for Nd. pH = 4.5-8 for Sm) and hydroxides prec ipitation (pH > 8) reactions. The distribution values Kd of Nd and Sm decre ase with rising nitrate concentrations. The mean ligand numbers, m, in Ln(N O3)(m)Ze((3-m)) species, formed in the zeolite phase, are 1.80 and 1.85 for Sm and Nd, respectively.