This study investigated the effect of salt solution chemistry on cesium loading of IONSIV(R) IE-911 (UOP LLC, Des Plaines, IL). The Savannah River Site (SRS) explored the use of this sorbent to remove cesium from the 35-million gallons of nuclear waste-supernatant and salt cake-stored on site. The proposed project has a cost estimated between $1.14 to $1.35 billion. The U.S. Department of Energy identified this technology as a backup in the Record of Decision.This study focused on salt solutions with different levels of carbonate, oxalate, and peroxide. The experiments examined the influence of these trace components on the performance of the sorbent, as even apparent minor variances in performance can dramatically influence the life-cycle cost of the project.Cesium loading on IE-911 increased with carbonate content in the simulated salt solution. Over the range of concentration (0 to 0.7 M) expected in SRS waste, the cesium loading increased by 38%. The variance likely results from a shift in sodium activity in the solution for increasing carbonate concentration. Removing (0-M) oxalate from simulated "average" salt solution had no effect on cesium loading. Peroxide at 0.1 M decreased the cesium loading on IE-911 by 16%. The expected peroxide concentration in average SRS waste is estimated as 2.6 x 10(-6) M. At this concentration level, interpolation of the data suggests no peroxide effect on cesium loading.