Adsorption of U(IV) by several geomaterials: kinetic, adsorbent dosage and thermodynamic

The behavior of U(IV) in the presence of several geomaterials (inorganic components of soils from an oyamel forest IMH(OF) and a semiarid zone IM(SZ), and two kinds of sands AS, AW) was studied. Kinetic data were best adjusted to the pseudo-second-order model. The order of the adsorption capacity was: IMH(OF) ae << IM(SZ) > AS ae AW. The adsorption efficiencies decrease as the adsorbent dosage increases (0.01-0.125 g) for all materials and do not depend on the concentrations of sodium chloride from 0.035 to 0.1 M. Thermodynamic parameters indicate that the adsorption processes is exothermic.