TITLE:
Application of 3A Zeolite Prepared from Venezuelan Kaolin for Removal of Pb (II) from Wastewater and Its Determination by Flame Atomic Absorption Spectrometry
AUTHORS:
Wendy Rondón, David Freire, Zully de Benzo, Angela B. Sifontes, Yorbin González, Maribel Valero, Joaquín L. Brito
KEYWORDS:
Adsorption; Wastewater; Lead (II) Ion; Zeolite; Langmuir Isotherm; FAAS
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.10,
October
11,
2013
ABSTRACT: 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 energy dispersive X-ray microanalysis (SEM-EDX).
The metal concentration in the equilibrium Ce (mg·L-1) after adsorption 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
described 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 were 14.64 and 5.42 respectively. The Pb (II) experimental
uptake was about 14.56 mg·g-1, a little smaller than the theoretical one
given by Langmuir isotherm model. The regression parameters and correlation
coefficients (R) indicate that the
adsorption data for Pb (II) removal fit better the Langmuir isotherm model.
Moreover, 0 1/n 1 (1/n is 0.13), indicating that
adsorption of metal ions on the zeolite, is a favorable
physical process. The application of removing of the metal lead from real
samples was examined by industrial wastewater samples. For all samples, the
percentage of recovery was found with accuracy of more than 98%. The present work
suggests 3A zeolite used as a sorbent material with relatively low cost,
obtained from Venezuelan raw material; it is a candidate for removal lead ion
and probably other cationic heavy metal species from wastewater.