The ion exchange systems of lead and cadmium, using the zeolite cinlin
optilolite, were examined. The metal uptake is increased with increasi
ng temperature. At low temperatures the exchange of lead is mainly wit
h the sodium ions but at higher temperatures potassium present in the
zeolite lattice can be replaced, increasing the metal uptake. In the c
ase of cadmium, the exchange occurs only with sodium ions, irrespectiv
e of the temperature of the solution. The zeolite particle size influe
nces significantly the metal uptake. An increase is observed with decr
easing particLe size. From the experimental results the diffusion coef
ficients and activation energies of the ion exchange systems are calcu
lated.