Kinetics of heavy metal ions removal by use of natural zeolite.

Kinetics of the uptake of cadmium, lead, copper, nickel and zinc ions from single ion solutions and from their mixture by zeolitic rock has been studied. Removal of ions obeyed the kinetic equation for adsorption. Corresponding adsorption constants and distribution coefficients were determined for each metal ion uptake from single ion solution or mixture. An attempt was made to explain zeolite selectivity to different metal ions and the influence of water hardness on the uptake in terms of metal ionic radii and enthalpy of hydration. It was found that lead ions were strongly immobilized by the zeolite investigated, both from single ion and mixed solutions, as well as from soft and hard water.