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The adsorption of Acid blue 25, basic blue 9, basic violet 3, Pb²⁺, Ni²⁺, Zn²⁺ and Cd²⁺ ions has been studied in single and dye–metal binary solutions using two mineral materials: Clinoptilolite (CL) and ER (Erionite). These zeolites were characterized by FT-IR spectroscopy; potentiometric titration and nitrogen adsorption isotherms at 77 K to obtain their textural parameters. Results indicated that ER has an acidic character and a high specific surface (401 m² g⁻¹) in contrast with the zeolite CL (21 m² g⁻¹). Surprisingly, the removal of dyes was very similar for the two zeolites and they showed a considerable selectivity by the basic dyes in comparison with the acid dyes. In the case of heavy metals, ER was more effective in the adsorption process showing a selectivity of: Pb²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺. In the multicomponent adsorption experiments an antagonistic effect was observed in the removal of basic dyes and …