Brazilian biomass applied to uranium removal from acid mine drainage by biosorption process

Abstract

This work aimed to evaluate the uranium concentration reduction in acid mine drainage. Brazil owns the sixth biggest uranium reserve in the world and there is large amount of accumulated tailings containing metallic, semi-metallic and radiotoxic ions. The method used in this study to remove uranium was biosorption by applying Brazilian biomass. The applied effluents were collected at the Osamu Utsaumi mine, which belongs to Industries Nucleares of Brazil and the biosorbents used in the tests were banana peel, moringa seed and spent coffee ground. Thermal decomposition, nitrogen adsorption porosimetry and scanning electron microscopy (SEM) were performed in order to characterize the biosorbents physically. From the results, it was observed that the biosorbents with a higher surface area and higher pore volume resulted in higher removal efficiency values, with an ascending order of these parameters: banana peels <spent coffee ground <moringa seeds. Considering the effluent samples with uranium concentration of 6 mg L^-1, the moringa seeds presented removal of approximately 87%, while the spent coffee grounds and banana peels presented removal of 74 and 56%, respectively