Adsorption of the bulky
complexes, particularly under weakly acidic conditions where
the resins exhibited higher metal adsorption, was predicted by
the Freundlich models. This suggests metal uptake occurred
by multilayer adsorption. The strong affinity of the resin for
H+ under acidic conditions promoted competitive adsorption.
This hampered the adsorption of the metal complexes and
promoted monolayer adsorption.