“…The sequence of adsorption followed should be associated with the volume of hydration (V hyd ) (34) presented by these cations, which are 147.8 for copper and nickel, and 169.6 cm 3 mol −1 for cobalt. The lowest adsorption for cobalt cation should be related to the largest hydration volume, which obstructs the adsorption capacity of the surface and, consequently, causes a decrease in the number of cations adsorbed (32).…”