Uranium removal from contaminated water by ion exchange resins

Abstract

In the nuclear fuel cycle, uranium containing liquid wastes can be produced in large quantities. There are several possible operations to separate this element from an aqueous solution. The classic examples are separation by solvent extraction and by precipitation when uranium is present in high concentrated solutions. In those cases where the element is present in concentrations as low as 100-200 μg mL-1, ion exchange technique can be very helpful to bring the uranium concentration to less than 10-20 ug mL-1. The synthetic resins used in ion exchange processes effectively remove metals from contaminated liquid wastes. This work intends to remove uranium from aqueous solutions by ion exchange technique. A column (10 cm in height and 1 cm in diameter) was used with 30 ml of dry Dowex 1-X8 strong anionic resin to fix and remove uranium from the solution. The solution with 155 mg.L-1 of uranium was percolated through the column with a flow of 4.0 mL.min-1. Resin was conditioned at pH = 7. The determination of the uranium contents was performed by Optical Emission Spectrometry with Argon Plasma Source (ICP-OES). The main operational parameters, such as pH, flow and column height, were evaluated to determine the best operating condition of the system. The results indicated approximately 99.9% removal of uranium from the application of the ion exchange technique. The percentage of removal allows the effluent to be properly disposed of in a sewage collection system in accordance with the regulations in force in the country.