Separation of trace radionuclides by ion exchange in the presence of competing ions

The performance of larger than bench scale ion exchange systems is evaluated by using solutions containing trace amounts of 137Cs, 85Kr, and 131I, and large amounts of either NaCl or Na2HPO4, H3BO3, and LiOH. The significant finding in this study is that the empirical rules of ionic selectivity of strong acid cation and strong base anion resins were followed by all ionic species, even though concentrations of some macrocomponents were nearly 106 times those of trace components. Other results of possible importance are the correlation between the instantaneous decontamination factor (DF) and the efficiency of column exchange capacity utilization, and the concept of time average decontamination factor (anti DF). The plot of anti DF vs. feed throughput will serve as a guide in determining when the feed should be discontinued in order to achieve a desired anti DF. Both of these correlations are derived from the breakthrough curves