Adsorption of metallic cations on silica gel-immobilized 8-hydroxyquinoline

TLC-grade silica gel was functionalized with 8-hydroxyquinoline via a catal yzed Mannich amminomethylation reaction. The resulting solid was characteri zed by FT-IR and used as a sorbent for 0.05-5 mmol.L-1 Cu(II), Cd(II), Zn(I I), Pb(II), and Fe(III) from aqueous solutions in the batch mode. Experimen ts were carried our in both single and multiple cation solutions. The influ ence of the aqueous media composition on the adsorption process, the possib le adsorbed species, and the adsorption kinetics are discussed. Overall equ ilibrium constants for these processes are reported.