CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Characterization of U(VI) Sorption and Leaching on Clay Supported Biomass Sorbents
Autor/es:
OLIVELLI, MELISA SOLEDAD; DANIEL DI GREGORIO; HUGO HUCK; JORGE FERNÁNDEZ NIELLO; TORRES SÁNCHEZ, ROSA MARÍA; CURUTCHET, GUSTAVO
Reunión:
Congreso; IBS 2013; 2013
Resumen:
In previous studies was demonstrated that matrixes generated from fungal biomass and a montmorillonite (BMMTs) are efficient as biosorbentes in batch uranium removal systems. BMMTs showed higher adsorption efficiency than montmorillonite or biomass even at low concentrations of U(VI). The objective of this article is to evaluate the U(VI) sorption capacity of BMMT systems for its removal from effluents and to determine the reusability of the sorbent and the recovery of the uranium testing different leaching solutions. Upflow BMMT columns were performed in order to optimize the system for continuous sorption techniques. The best relation between clay and biomass in the matrix was selected and fixed-bed columns (volume of 0,8 ml) were loaded with a solution of 25 ppm U(VI). A peristaltic pump was used at a flow rate of 0.65 ml/min. For batch leaching experiments BMMTs were loaded with an initial concentration of 300 ppm U(VI) until equilibrium was reached. The quantity of U(VI) adsorbed was determined by gamma-ray spectroscopy and the remaining U(VI) in the solution was determined spectroscopically by arsenazo(III). U(VI) adsorbed on BMMTs were extracted with commercial and biogenerated (generated as a bioproduct in an A. thiooxidans reactor) H2SO4 0,2 N. For upflow columns, the U(VI) removal percentage was around 75% during the first 1150 ml of U(VI) loading solution and 35% from 1150 to 1725 ml. The total amount of U(VI) retained during the 2156 bed volumes, was near 77 mg U(VI) / g BMMT. Treatment of U(VI) loaded BMMTs with leaching solutions allowed calculating U(VI) extraction percentages. These results indicated the possibility of recycling the sorbent after processes of U(VI) sorption, because U(VI) extraction from the loaded BMMTs was near 80% the total amount of the retained metal in the column. These results indicated that the use of clay supported biomass sorbents in upflow columns presented strong potential for uranium retention and that they could be used in the development of economic and efficient biofilters.