Competitive Exchange of Lead(II) and Cadmium(II) from Aqueous Solution on Clinoptilolite

1. M.S. Berber-Mendoza, R.Leyva-Ramos, J. Mendoza Barron y R.M. Guerrero Coronado
Studies in Surface Science and Catalysis 142, 1849-1856., 2002.


The experimental data for the single exchange isotherms for Pb(ll) and Cd(ll) were adjusted quite well by the Langmuir isotherm and the exchange capacity for the Pb(ll) ion is about'2.3 times that for the Cd(ll) ion. The resúlts of the competitive exchange showed that the ion exchange isotherm for Pb(ll) was not significantly dependent upon the Cd(ll) concentration, this means that Pb(ll) ion w~s,~~changed more selectively than the Cd(ll) ion. ' However, the exchange isotherm for Cd(II) was considerably affected by the presence of Pb(ll) .ions. The exchange capacity toé Cd(II) diminished drastically increasing the concentration of Pb(ll) ion. Therefore, both ions compete for the same cationic sites of the zeolite but the zeolite is much more selective for the Pb(ll) ion than for the Cd(ll) ion .