The removal of some rare earth elements from their aqueous solutions on by-pass cement dust (BCD)

The sorption behavior of yttrium (Y(3+)), neodymium (Nd(3+)), gadolinium (Gd(3+)), samarium (Sm(3+)) and lutetium (Lu(3+)) from their aqueous solutions by by-pass cement dust (BCD) has been investigated using a batch technique. The sorption on BCD was studied as a function of pH, shaking time, initial concentration, mass of BCD and temperature. It was found that the sorption capacity of BCD had the order of Lu(3+) > Sm(3+) > Y(3+) > Gd(3+) ≈ Nd(3+) following Freundlich isotherm at the determined optimum conditions. The results also demonstrated that the sorption data fit well the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° indicated that the sorption of the investigated REEs on BCD was endothermic, favored at high temperature and spontaneous in nature.