CONICET | Buscador de Institutos y Recursos Humanos

In previous studies was demonstrated that matrixes generated from fungal biomass and a montmorillonite (BMMTs) were efficient as biosorbentes in batch uranium removal systems. BMMTs showed higher adsorption efficiency than montmorillonite or biomass even at low concentrations. 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 with a 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 (A. thiooxidans) H2SO4 0,2 N. For upflow columns, the U(VI) removal percentage was around of 75% during the first 1150 ml of loading. The total amount of U(VI) retained during the 2156 bed volumes, was near 77 mg U(VI) / g BMMT. Data from U(VI) extraction after leaching solutions indicated the possibility of recycling the BMMT after processes of U(VI) sorption, because U(VI) extraction from the BMMTs was near the 80% of metal recovery. 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

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