Mineral Species to Removal Contaminants: Characterization Trough Dynamic Speckle Techniques

MARÍA J. GONZÁLEZ, GUILLERMO BERTOLINI, IRMA L. BOTTO, CARMEN I. CABELLO, R. ARIZAGA AND MARCELO TRIVI

Congreso; ICO-22 22nd General Congress of the International Commission for Optics (ICO); 2011

The dynamic speckle laser technique has been applied to the analysis of different biological systems, inorganic materials and industrial processes. The temporary evolution of the dynamic effect attributed to the presence of mobile scatterers is an interesting tool for characterization of mineral properties in environmental chemistry. In this paper we use dynamic speckle to analyze geomaterials (original and modified mineral species) for the removal of toxic anions in drinking water (arsenate and fluoride). We reported hydroadsorption results obtained with iron-rich clays from domestic deposits and products of chemical modification in order to increase the iron content. The characterization of the original and modified species was made by XRD, chemical analysis (ICP ES), BET and SEM-EDS techniques. The mineralogy of the starting material is dominated by laminar alumina-silicates with the presence of iron oxides (with different crystallinity). The mineral was modified by precipitation in situ of nanoscopic ferrihydrite phase, obtained from a solution of trivalent iron salt by adjusting the pH. The experimental speckle results let us conclude that the system activity is related to different physicochemical properties and mineral structure, type of surface bonds (Si, Al, Fe-OH), chemical composition and textural characteristics of the solid.