Adsorption of copper ions from aqueous solutions on natural zeolite

The adsorption of copper ions from synthetic aqueous solutions on natural zeolite (clinoptilolite) was examined. In order to determine the rate of adsorption and the copper uptake at equilibrium, a series of experiments were performed under batch conditions from single ion solutions. Equilibrium data were evaluated based on adsorption (Langmuir and Freundlich) isotherms. The adsorption kinetics is reasonably fast. In the first 20 min of the experiment, approximately 80% of Cu2+ ions is adsorbed from the solutions. Data obtained from the kinetic experiments have been described by the pseudo-second order kinetic model as well as by the Weber–Morris and Furusawa–Smith models.