Adsorption of Metallic Cations on Silica Gel-Immobilized 8-Hydroxyquinoline

TLC-grade silica gel was functionalized with 8-hydroxyquinoline via a catalyzed Mannich amminomethylation reaction. The resulting solid was characterized by FT-IR and used as a sorbent for 0.05–5 mmol·L−1 Cu(II), Cd(II), Zn(II), Pb(II), and Fe(III) from aqueous solutions in the batch mode. Experiments were carried out in both single and multiple cation solutions. The influence of the aqueous media composition on the adsorption process, the possible adsorbed species, and the adsorption kinetics are discussed. Overall equilibrium constants for these processes are reported.