AWWA WKICO66052

Uranium is naturally present in the environment. Where present in potable water, 80% ofour total daily intake of uranium can be derived from drinking water. Currently noEuropean Union (EU) standards exist for uranium in drinking water. Recommendationshave been made by the World Health Organization (WHO) for a more rigorous referencelevel for uranium in drinking water supplies; there is the possibility that this will beincorporated in United Kingdom regulations in the long term.Severn Trent Water (STW) in the United Kingdom reviewed and identified water sources at risk.STW commissioned a study to identify suitable adsorbents orion exchange resins for removal of uranium. This identified that a strong base anionexchange resin exhibited the greatest capacity for uranium removal.Trials using strong base anion exchange resins were subsequently carried out at agroundwater source containing uranium levels between 13 and 19 g/l. An initialtreatment run of 16,000 bed volumes (BV), showed no uranium breakthrough, the resinwas regenerated with 5% sodium chloride. A second run achieved treatment of 265,000BV without any significant breakthrough of uranium. After regeneration, the performancewas monitored over a period of 11 months. The regenerated resin again performedexceptionally well with minimal impact on the resins capacity to remove uranium. After300,000 bed volumes the uranium level in the treated groundwater was 3 g/l.Successful uranium removal from drinking water has been established; the best practicefor operating a full scale plant is currently under review. STWs focus is on wastedisposal; adsorbed uranium can be disposed of in an aqueous form either frequently orinfrequently depending on regeneration intervals, or as a solid with no regenerationtaking place. Includes tables, figures.



Keywords: Uranium; Resins; Regeneration; United Kingdom; Ion Exchange