Preparation of zeolite A by inorganic complex precursor route for efficient elimination of heavy metal cations from aqueous solutions

Abstract

In the present study, zeolite A was synthesized via inorganic complex precursor as an efficient novel route by using tris(acetylacetonato)aluminum(III), [Al(C5H7O2)3], and tris(acetylacetonato)silicon(IV) chloride hydrochloride, [Si(C5H7O2)3]Cl.HCl. The physicochemical properties of the zeolite A were characterized by FT-IR, XRD, SEM/EDX, BJH, and BET techniques. The performance of the synthesized zeolite A was evaluated for the elimination of heavy metal cations (Co2+, Cu2+, Zn2+, Cr3+ and Pb2+) from aqueous solutions. The results revealed that removal efficiencies of the synthesized zeolite A toward all investigated heavy metal cations were obtained to be more than 95% and the maximum removal efficiency was observed for Pb2+. The influence of parameters such as pH, contact time and adsorbent amount was surveyed on the removal efficiency of Pb2+ by the zeolite A. The most desirable conditions for Pb2+ removal was attained at pH 6.5, the zeolite amount of 0.5 g, 400 mgL−1 initial concentration of Pb2+ and the contact time of 30 min. The adsorption process followed second- order kinetics model and the pseudo-second-order adsorption rate constant (k 2) was obtained to be 4.32 × 10−4 g mg−1min−1.