CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effect of hydration of bio-clay matrices on urainum adsorption, applications in upflow columns
Autor/es:
M. OLIVELLI; R. M. TORRES SÁNCHEZ; B. SCHAMPERA; G. CURUTCHET
Lugar:
Dresden
Reunión:
Conferencia; MECC14 7th MID-EUROPEAN CLAY CONFERENCE; 2014
Resumen:
In previous studies, the generation and characterization of bio-clay matrices (BMMT) was efficient for the removal of U(VI) from aqueous solutions (Olivelli et al. 2013). Previous results indicated that dried BMMT presented an increase of the uranium adsorption capacity compared to wet systems. Previous results indicated that BMMT presented optimal characteristics for their use as bio-filters for the removal of U(VI) (Olivelli et al. 2012). The objective of this work is to study the causes of the increase in the adsorption capacity of dry BMMT and their use in U(VI) adsorption upflow columns. Hydration rates of previously dried BMMT were determined. These percentages were correlated with the U(VI) adsorption ability of wet and dry systems and the mass of water that entered to the matrices during the rehydration process. Also, U(VI) adsorption capacity of dry, wet and rehydrated BMMT samples, were compared. Upflow adsorption columns using pellets of BMMT were performed. The effective diffusion coefficient (Deff) was determined. BMMT showed diffusion coefficients comparable to those of natural clay. At dry bulk densities between 1.5 and 2 g/cm³ no influence on the diffusive transport regarding the surface changes by biopolymers could be detected. The U(VI) adsorption capacity of rehydrated systems was similar to that found for wet systems. This may indicate that differences in the U(VI) adsorption capacity between the wet and dry samples were due to conformational changes that occurred during the drying process. BMMT stability in columns depended on the biomass/MMT relationship; and this was optimized. Values of maximum adsorption capacity in columns were lower than adsorption capacity in batch systems. The effective diffusion coefficient increased with decreasing density for all samples. BMMT presented an efficient adsorption performance for continuous adsorption processes; not only for its uranium retention high values (efficiencies up to 80%), but also they presented adequate stability of the material and the possibility of recovery. Olivelli, MS, Curutchet, GA y Torres Sánchez, RM, 2012. XI Jornadas Argentinas de Tratamiento de Minerales. Neuquén, Argentina. Olivelli, MS, Curutchet, GA y Torres Sánchez, RM, 2013. Ind. Eng.. Chem. Res.. 52, 2273-2279.