Benzalkonium Chloride surface adsorption and release by two montmorillonites and their modified organomontmorillonites

FEDERICO M. FLORES; ROBERTO CANDAL; FLORENCIA YARZA; ELSA GABRIELA LÓPEZ LOVEIRA; ROSA MARÍA TORRES SANCHEZ

WATER AIR AND SOIL POLLUTION

SPRINGER

Lugar: Berlin; Año: 2017 vol. 228 p. 1 - 14

0049-6979

Benzalkonium chloride (BAC) loaded to montmorillonites (Mt) or organo-Montmorillonites (OMt) generates a functional material that can be incorporated to several systems (polymers, paints, etc) as a controlled release bactericide. Understanding the BAC adsoption sites on these adsorbents is of high importance to clarify their adsorption/desorption characteristics in aqueous media or other solvents. In this work a thorough study about the adsorption/desorption properties of Mt and OMt with regards to BAC is presented, in order to evaluate further BAC release with the consequent aquatic environment contamination. In this work it is demonstrated the BAC adsorption on two different sites, the interlayer space and the external surface. Depending on BAC concentration in water, sorption of BAC at Mt occurred in two steps. At Ceq0.5 mM there was a new interlayer expansion attaining 0.75 nm and the external charge shifted to positive value. In the case of OMt, the introduction of BAC produced changes in the interlayer structure and in the external surface charge. BAC desorption was strongly dependent on the type of Mt or OMt and extraction solvent, knowledge of which will allow its safe use in environmental friendly technological applications.