Synthesis of Novel Edta-Modified Aluminum Oxide for Improved Removal of Heavy Metal in Contaminated Water

Abstract

In this study, aluminum oxide (Al2O3), with large surface area and porous structure, was chemically modified by ethylenediaminetetraacetic acid (EDTA) using the biopolymer poly(vinyl alcohol) (PVA) as a binder to produce Al2O3/PVA-EDTA nanocomposite for enhanced Pb2+ adsorption. The optimized parameters including modifier content, solution pH, adsorbate concentration, and sorbent mass on Pb2+ adsorption efficiency were 1.0 M, 6, 60 ppm, and 0.25 g/L, respectively. Under optimum conditions, the removal efficiency and sorption capacity were 87.34% and 209.61 mg/g with a rate constant of 0.005 g.mg-1.min-1. The Pb2+ removal proceeded quickly, reaching a steady state within the initial 10 min. The adsorption are most compatible with Langmuir isothermal and the maximum uptake capacity obtained as 467.29 mg/g. Moreover, the Pb2+ ions were effectively re-adsorbed onto the adsorbent after the 5th cycle are equivalent to 97.65% for the 1th cycle, proving that the Al2O3/PVA-EDTA nanocomposite is a reliable candidate for practical applications.

Keywords: Aluminum oxide, EDTA, Surface modification, Heavy metal, Adsorption