title: Nanoscale zero valent supported by Zeolite and Montmorillonite: Template effect of the removal of lead ion from an aqueous solution.
abstract: In this work, we have studied the Pb(2+) sorption capacity of Zeolite (Z) and Montmorillonite (Mt) functionalized with nanoscale zero-valent iron (nZVI), at 50% w/w, obtained by means of an impregnating process with a solvent excess. The composites were characterized by several techniques including X-ray diffraction; scanning electron microscopy (SEM); BET area; isoelectric point (IEP); and, finally a magnetic response. Comparatively significant differences in terms of electrophoretic and magnetic characteristics were found between the pristine materials and the composites. Both structures show a high efficiency and velocity in the removal of Pb(2+) up to 99.0% (200.0 ppm) after 40 min of reaction time. The removal kinetics of Pb(2+) is adequately described by the pseudo second-order kinetic model, and the maximum adsorbed amounts (q(e)) of this analyte are in close accordance with the experimental results. The intraparticle diffusion model shows that this is not the only rate-limiting step, this being the Langmuir model which was well adjusted to our experimental data. Therefore, maximum sorption capacities were found to be 115.1±11.0, 105.5±9.0, 68.3±1.3, 54.2±1.3, and 50.3±4.2 mg g(-1), for Mt-nZVI, Z-nZVI, Zeolite, Mt, and nZVI, respectively. The higher sorption capacities can be attributed to the synergetic behavior between the clay and iron nanoparticles, as a consequence of the clay coating process with nZVI. These results suggest that both composites could be used as an efficient adsorbent for the removal of lead from contaminated water sources.
authors.affiliation: Facultad de Química y Biología, CEDENNA, Universidad de Santiago de Chile, USACH, Casilla 40, Santiago C.P. 33, Chile. Electronic address: nicolas.arancibia@usach.cl.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Arancibia-Miranda
authors.affiliation: Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago 9170124, Chile.
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Baltazar
authors.affiliation: CIMAV, S.C. Alianza Norte 202, Carretera Monterrey-Aeropuerto Km 10, C.P. 66600, Apodaca Nuevo León, Mexico; University of Texas at San Antonio, Physics and Astronomy Department, One UTSA circle 78249, San Antonio, Texas, USA.
authors.forename: Alejandra
authors.initials: A
authors.lastname: García
authors.affiliation: Facultad de Química y Biología, CEDENNA, Universidad de Santiago de Chile, USACH, Casilla 40, Santiago C.P. 33, Chile; Facultad de Ciencias, Universidad de Chile, UCH, Las Palmeras 3425, Santiago 7800024, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Muñoz-Lira
authors.affiliation: Facultad de Química y Biología, CEDENNA, Universidad de Santiago de Chile, USACH, Casilla 40, Santiago C.P. 33, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Sepúlveda
authors.affiliation: Facultad de Química y Biología, CEDENNA, Universidad de Santiago de Chile, USACH, Casilla 40, Santiago C.P. 33, Chile.
authors.forename: María A
authors.initials: MA
authors.lastname: Rubio
authors.affiliation: Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago 9170124, Chile.
authors.forename: Dora
authors.initials: D
authors.lastname: Altbir
keywords: Lead; Montmorillonite; Nano zero valent iron; Sorption; Zeolite