Application of 3A Zeolite Prepared from Venezuelan Kaolin for Removal of Pb(II) from Wastewater and Its Determination by Flame Atomic Absorption Spectrometry

Copyright © 2013 Wendy Rondón et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This work consists in the use of a 3A zeolite (K-LTA) obtained by a process of exchange of sodium for potassium (4A zeolite), synthesized from Venezuelan kaolin for the removal of Pb (II) ions from aqueous solutions by batch process mode in order to consider its application in treating industrial wastewaters. The 3A zeolite was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy and en-ergy dispersive X-ray microanalysis (SEM-EDX). The metal concentration in the equilibrium Ce (mg·L−1) after adsorp-tion with 3A zeolite was analyzed using flame atomic absorption spectrometry (FAAS). The influences of the solution pH, contact time, metal initial concentration and adsorbent dosage have been studied. The retention of metal occurring at pH values around 6.5 and the adsorption equilibrium was obtained at 60 min. The equilibrium process was well de-scribed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir parameters qm (mg·g−1) and b (L·mg−1) (which are related to the sorption capacity and constant of sorption energy) obtained wer