SYNTHESIS AND CHARACTERIZATION OF γ-Al2O3@MgO SORBENT FOR EFFICIENT REMOVAL OF Pb FROM AQUEOUS SOLUTIONS

Abstract

This study focuses on enhancing the adsorption capacity for lead ions by introducing MgO onto the surface of γ-Al₂O₃, forming γ-Al₂O₃@MgO. The γ-Al₂O₃ nanoparticles were synthesized via the sol-gel method on a citrate template. MgO was incorporated onto the surface of the γ-Al₂O₃ nanoparticles, with varying MgO concentrations (5%, 10%, and 15% by weight), achieved through the absorption of magnesium ions onto the material's surface followed by sintering at 773K. The findings indicated that both the γ-Al₂O₃ and MgO crystalline phases exhibit a cubic structure (Fd3m symmetry group), which is formed within the sample. Although the specific surface area diminished from 166 m²/g to 135 m²/g, the surface basicity increased proportionally to the amount of MgO incorporated into the sample. The impacts of various absorption conditions such as pH, adsorbent mass, and contact time on the Pb²⁺ ion adsorption capacity was systematically examined. Optimal conditions (pH = 7, adsorption time of 8 hours) highlighted that the γ-Al₂O₃ material containing 10% MgO by weight showcased the highest Pb²⁺ adsorption capacity at 145 mg/g, surpassing the adsorption capacity of 135 mg/g for the γ-Al₂O₃ material.