Title: Effect of the surfactant benzalkonium chloride in the sorption of paraquat and cadmium on montmorillonite

Authors: Romina Ilari; Mariana Etcheverry; Cristina Zenobi; Graciela Zanini

Addresses: INQUISUR, Departamento de Química, Universidad Nacional del Sur. Av. Alem 1253, Bahía Blanca 8000, Argentina ' INQUISUR, Departamento de Química, Universidad Nacional del Sur. Av. Alem 1253, Bahía Blanca 8000, Argentina ' INQUISUR, Departamento de Química, Universidad Nacional del Sur. Av. Alem 1253, Bahía Blanca 8000, Argentina ' INQUISUR, Departamento de Química, Universidad Nacional del Sur. Av. Alem 1253, Bahía Blanca 8000, Argentina

Abstract: Pesticides, heavy metals and surfactants can share the same region or site in the environment and thus they may compete for the surface of minerals. A competitive study of the adsorption between the cationic surfactant benzalkonium chloride (BAC) with the heavy metal cadmium (Cd(II)) and the cationic herbicide paraquat (PQ) on montmorillonite is presented. Adsorption isotherms for BAC, PQ and Cd(II) were performed in single solute systems and also in binary solute systems, PQ+BAC and Cd(II)+BAC to evaluate the effects of BAC on the adsorption of the other two substances. The affinities of BAC and PQ were strong and similar, thus BAC affected significantly the adsorption of PQ and vice versa. The affinity of Cd(II) for the montmorillonite surface was low, thus BAC affected appreciably Cd(II) adsorption, but the heavy metal did not modify BAC adsorption. XRD data show that BAC molecules control the magnitude of the basal spacing.

Keywords: BAC; benzalkonium chloride; paraquat; cadmium; heavy metals; montmorillonite clay; competitive adsorption; isotherms; surfactants; pesticides; sorption; basal spacing.

DOI: 10.1504/IJENVH.2014.060127

International Journal of Environment and Health, 2014 Vol.7 No.1, pp.70 - 82

Published online: 13 Oct 2014 *

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