Adsorption of Pb (II) and Zn (II) ions on Libyan kaolinite from Aqueous Solutions, (Isotherms Study)

Abstract

This investigation was carried out to follow the ability of Libyan kaolinite as a new local natural adsorbent to adsorb lead Pb (II) and zinc Zn (II) ions from water using the laboratory batch method. The chemical structure of Libyan kaolinite adsorbent was investigated by XRF. The factors influencing the adsorption process, including pH, contact time, initial metal concentration, and the amount of kaolinite were studied, and the XRF results showed that Libyan kaolinite contains SiO₂ (49.0%) and Al₂O₃ (34.2%) as main compounds. The equilibrium adsorption results were analyzed by both Langmuir and Freundlich models to follow the mechanism of the adsorption process, according to the Langmuir equation the optimum adsorption capacity (mg\g) was 13.41 and 9.03 for Pb (II) and Zn (II) respectively at pH 3, 5. The equilibrium time was reached within 40 min for both metals. By increasing the initial metal ions concentration, the adsorption efficiencies were decreased, and the adsorption capacity of was increased with an increase in the initial pH. The results demonstrate the potential of Libyan kaolinite as a cost-effective and sustainable adsorbent for removing heavy metals from aqueous solutions, offering valuable insights for water treatment applications.