Abstract This study explores the adsorption efficiency of NaX zeolite for the removal of Pb 2 ⁺ ions from aqueous solutions. NaX zeolite was synthesized via a hydrothermal method at 100 °C for 24 h using aluminium isopropoxide as the alumina source. The material was characterized by X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET analysis. The removal of Pb 2 ⁺ by NaX zeolite was studied in batch mode under different conditions: pH (2.0–6.0), initial Pb 2 ⁺ concentration (50–200 mg/L), contact time (5–150 min), (solid/liquid) ratio (0.1–0.6 g/L), and temperature (298–323 K). The highest removal efficiency of Pb 2 ⁺ ions (99%) was achieved at a concentration of 75 mg/L, with a contact time of 10 min, a natural pH ∼ 5, an (S/L) ratio of 0.3 g/L, and at 298 K. Adsorption equilibrium was best described by the Langmuir isotherm ( R 2 = 0.9888), with a maximum capacity of 500 mg/g, while the adsorption kinetics followed the pseudo‐second‐order model with a coefficient of determination (R 2 > 0.99). Thermodynamic analysis indicated that the process is spontaneous and exothermic, with an activation energy of 11 kJ/mol, confirming physisorption. These results highlight the effectiveness of NaX zeolite as a promising low‐cost adsorbent for Pb 2 ⁺ removal from contaminated water.
Bentaieb et al. (2025) studied this question.