Evaluation of Natural Phillipsite and Chabaziteas Cation Exchangers for Copper and Zinc

Abstract
Chabazite and phillipsite, two zeolites widespread in many volcaniclastic deposits in central-southern Italy, were evaluated as cation exchangers for the removal of copper and zinc from aqueous solution. Equilibrium and kinetics of copper and zinc exchange reactions for sodium were investigated in order to verify the selectivity and the uptake rate of both zeolites for these heavy metals. Thermody-namic quantities, such as equilibrium constant, K a, and δG′, as well as rate constant, K, were computed, and they showed that Na-chabazite displays a moderate selectivity and a favorable kinetics for copper, whereas in all the other cases uses in wastewater treatment are not recommended.