Removal and recovery of uranium by modified <i>Pinus radiata</i> D. Don bark

Abstract

Abstract Bark from Pinus radiata D. Don was treated with both sulfuric acid/formaldehyde and nitric acid/formaldehyde. The ability to adsorb uranium by the bark was improved by these treatments, with essentially zero bleed colour into solution. The resin produced by nitric acid/formaldehyde treatment showed, in general, a better retention capacity than that of sulfuric acid/formaldehyde treatment. The nitric acid/formaldehyde modified bark showed 96 % of adsorption of uranium after 1 h and 63 % of desorption from the loaded resin after 3 h in 0.5 M sulfuric acid solution. Unmodified bark and some bark components were also analyzed. Bark was shown to be an excellent adsorber, comparable in efficiency, but costing less than the commercial adsorbing agents.