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Sorption of Cd 2+ , Ni 2+ and Zn 2+ ions on natural (ZPCli), sodium modified (ZPCliNa) and acid modified (ZPCliH) zeolites have been investigated in function of the contact time, pH, and metal concentration by the batch technique. The characterization of ZPCli, ZPCliNa, and ZPCliH materials was performed using X-ray powder diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. The surface area (BET) and the pHpzc were also determined. The pH in the point of the zero charge of ZPCli, ZPCliNa, and ZPCliH zeolites was 8.25, 8.00, and 2.05, respectively. The kinetic sorption data for ZPCli, ZPCliNa and ZPCliH were well fitted to the pseudo-second order model (R 2 > 0.99). The linear model described the Cd, Ni and Zn sorption isotherms for ZPCliH, while for ZPCliNa and ZPCliH it was the Freundlich model. The unmodified and modified zeolitic materials showed the highest sorption capacity for Cd 2+ , lower for Zn 2+ and Ni 2+ .

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Removal of phenol (Phen) and p-nitrophenol (p-NPhen) from aqueous solutions onto sodium modified (ZG-Na) and surface modified (ZG-HDTMA) natural zeolite has been investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) technique characterizations show that clinoptilolite is the major phase in zeolitic rock. Batch system was considered to determine the kinetics and isotherm type of the adsorption of 3 NO − by the ZG-Na and ZG-HDTMA. Results suggest a better fit to the adsorption data than the pseudo-first order kinetic model. It seems that the Langmuir model best describes the experimental data. p-NPhen is selectively adsorbed by both ZG-HDTMA and ZG-Na.