Evaluation of improved technologies for the removal of {sup 90}Sr and {sup 137}Cs from process wastewater and groundwater: FY 1995 status

A number of new sorbents are currently being developed for the removal of {sup 90}Sr and {sup 137}Cs from contaminated, caustic low-level liquid waste (LLLW). These sorbents are potentially promising for use in the cleanup of contaminated groundwater and process wastewater containing the two radionuclides. The goal of this subtask is to evaluate the new sorbents to determine whether their associated treatment technology is more selective for the decontamination of wastewater streams than that of currently available processes. Activities during fiscal year 1995 have included completing the characterization of the standard treatment technology, ion exchange on chabazite zeolite. Strontium and cesium sorption on sodium-modified zeolite was observed in the presence of elevated concentrations of wastewater components: sodium, potassium, magnesium, and calcium. The most significant loss of nuclide sorption was noted in the first 0- to 4-meq/L addition of the cations to a wastewater simulant. Radionuclide sorption on the pretreated zeolite was also determined under dynamic flow conditions. Resorcinol-formaldehyde (R-F) resin, which was developed at the Savannah River Site, was selected as the first new sorbent to be evaluated for wastewater treatment. Nuclide sorption on this resin was greater when the resin had been washed with ultrapure water and air dried prior to use