SYNTHESIS AND CHARACTERIZATION OF γ-Al2O3@MgO SORBENT FOR EFFICIENT Pb REMOVAL 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.