05/02504 Performance of three resin-based materials for treating uranium-contaminated groundwater within a PRB

Abstract

Three materials that are designed to treat uranium-contaminated water were investigated.These are a cation exchange resin, IRN77, an anion exchange resin, Varion AP, and a recently developed material called PANSIL (quartz sand coated with 2% amidoxime resin by wt.). The reaction rate, capacity, and effective pH range of the three materials are reported. The capacity and conditional distribution coefficient in neutral, uranyl contaminated synthetic groundwater containing carbonate are also reported. The suitability of each material for treating uraniumcontaminated groundwaters using a permeable reactive barrier approach is then discussed.All three materials react rapidly in the pH range 5-7, reaching equilibrium in less than 4 hours at ~23°C. The unconditioned cation exchange resin removed 8 g UO effective at sequestering cationic and neutral uranyl species from solutions in the pH range 4.5 to 7.5, with very good specificity. The capacity of PANSIL is pH dependent, increasing from about 0.4 g/kg at pH 4.5, to about 1 g/kg at pH 6 and 1.5 g/kg around pH 7.5. In neutral groundwater containing carbonate, both the anion exchange resin and PANSIL exhibit conditional distribution coefficients exceeding 1470 ml/g, which is about an order of magnitude higher than comparable reactive barrier materials reported in the literature.