Modifying ion exchange for combined removal of uranium and radium

Adding a small amount of strong base anion (SBA) resin to the strong acid cation (SAC) resin in a conventional water softener provides good uranium and radium removal. In tests on a well water containing 25 pCi/L radium and 120 μg/L uranium, a mixed bed containing 10 percent SBA and 90 Percent SAC resin provided a product water with less than 1 pCi/L radium and 20 μg/L uranium during cyclic operation with sodium chloride regeneration. Additional tests indicated that too much anion resin or stratified resin beds caused excessive radium and uranium leakage. Also, potassium chloride was a superior regenerant to sodium chloride for elution of radium from the spent resin