Palygorskite clay mineral (Pal) was employed to the removal of Congo red (CR) and methylene blue (MB) dyes pollutants in aqueous effluents by the adsorption process. The materials, Pal raw and acid Pal (Apal), were characterized by N2 adsorption/desorption isotherms XRD and XFR techniques that evidenced the main active sites of clay mineral. Characterization data indicated that acid treatment caused a leaching process of metallic cations on the Pal surface. As result, the maximum adsorption capacities were increased from 11.3 to 120.5 mg.g-1 and from 2.7 to 238.1 mg.g-1 for MB and CR dyes, respectively. The regeneration result after five cycles was of 75% recovered to MB adsorption into Apal. Semi-empirical quantum mechanical (SQM) calculations were performed to identify the mechanism of interaction between the Pal surface and dyes. High correlation (R2 > 0.99) was observed for the experimental data using the pseudo-second order kinetic model, that were confirmed by computed enthalpy values (-298.7 to -84.5 kJ.mol-1), suggested a chemisorption process as the determining step.