Book Description

As part of the Efficient Separations and Processing Crosscutting Program, the Pacific Northwest National Laboratory conducted this study to demonstrate the efficiency of several ion-exchange materials in removing strontium-90 from actual groundwater from the Hanford N-Springs Pump and Treat Demonstration Facility. The objective of this experiment was to determine the strontium-loading distribution coefficients (Kds) for some titanate ion-exchange materials, modified minerals, and organic ion-exchange resins. The equilibrium uptake data presented in this report are useful for identifying potential materials that are capable of removing strontium from N-area groundwaters. The data show the relative selectivities of the ion-exchange materials under similar operating conditions, and show that additional flow studies are needed to predict materials capacities and to develop complete ion-exchange process flow sheets. The materials investigated in this study include commercially available ion exchangers such as IONSIV IE-911 (manufactured by UOP) and SuperLig 644 (IBC Advanced Technologies, Inc.), and materials produced on an experimental basis by Allied Signal (nontitanates), Selion Inc. (titanates), and Pennsylvania State University (modified mica). In all, the performance of seven different ion-exchange materials was evaluated using actual N-Area groundwater. The evaluation consisted of the determining strontium batch distribution coefficients, loading, and decontamination factors. Tests were performed at two different solution-to-exchanger mass ratios (i.e., phase ratios) of 2000 and 4000 using actual N-Area groundwater samples from three different wells. Actual N-Area groundwater used in the present study was obtained from three monitoring wells in FY 1998. These samples were taken from wells with strontium-90 concentrations ranging from 0.25 to 3.9 pCi/L.