Title: Adsorption of lead ions in contaminated water using commercial hydrophilic silica nanoparticles

Authors: Susana Vargas; Rogelio Rodríguez; Maykel González Torres; Bárbara Álvarez; Francisco Quintanilla; Sadott Pacheco; Antonio Rodríguez-Canto

Addresses: Universidad Nacional Autónoma de México, Centro de Física Aplicada y Tecnología Avanzada, Campus Juriquilla, Apdo. Postal 0-1010, Querétaro, Qro., CP 76000, México ' Universidad Nacional Autónoma de México, Centro de Física Aplicada y Tecnología Avanzada, Campus Juriquilla, Apdo. Postal 0-1010, Querétaro, Qro., CP 76000, México ' Universidad Nacional Autónoma de México, Centro de Física Aplicada y Tecnología Avanzada, Campus Juriquilla, Apdo. Postal 0-1010, Querétaro, Qro., CP 76000, México ' Universidad del Valle de México, Campus Querétaro, Querétaro, México ' Universidad del Valle de México, Campus Querétaro, Querétaro, México ' Instituto Mexicano del Petróleo, Eje Central L. Cárdenas 152, Apdo. Postal 14-805, C.P. 07730, México ' Departamento de Hidrobiología, DCBS, UAM-Iztapalapa, Apdo. Postal 55-534, México, D.F. 09340, México

Abstract: The adsorption of lead ions from simulated industrial wastewater using hydrophilic commercial silica nanoparticles (Aerosil A130VS) is reported. These results were compared with those obtained using sol-gel silica nanoparticles prepared in our laboratory. Hydrated commercial silica nanoparticles have, on their surface, silanol groups (≡Si-OH) that are appropriated for the adsorption process. The commercial particles are dense because they are produced by a pyrogenic process. The absence of pores means a smaller internal surface area and, consequently, a smaller number of silanol groups available for adsorption; as compared with the highly porous sol-gel silica nanoparticles. This effect is partially compensated by the small particle size that can be obtained from these commercial particles. Different concentrations of lead ions in aqueous solution were added to a suspension of commercial particles until the critical flocculation concentration was reached. The flocculation kinetic was obtained using dynamic light scattering and the amount of adsorbed lead ions using atomic absorption. The lead concentration was reduced from 65.9 ppm to 0.2 ppm using Aerosil A130VS.

Keywords: lead ions; commercial silica nanoparticles; adsorption; dynamic light scattering; DLS; atomic absorption; hydrophilic groups; water pollution; simulation; industrial wastewater; wastewater treatment; nanotechnology; sol-gel; silanol groups; flocculation concentration; kinetics.

DOI: 10.1504/IJEP.2015.077194

International Journal of Environment and Pollution, 2015 Vol.58 No.3, pp.215 - 227

Accepted: 22 Jan 2016
Published online: 17 Jun 2016 *

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