Small-Column Ion Exchange Testing of Spherical Resorcinol-Formaldehyde

Conference · Wed Mar 02 23:00:00 EST 2011

OSTI ID:1179147

Brown, Garrett N.; Russell, Renee L.; Peterson, Reid A.

Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy’s Office of River Protection (DOE-ORP) for use in the Pretreatment Facility (PTF) of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment. Numerous studies have shown the SRF resin to be effective for removing Cs-137 from a wide variety of actual and simulated tank waste supernatants. Prior work focused primarily on the loading behavior for 5 M sodium (Na) solutions at 25°C and the eluting behavior of the loaded SRF resin with virgin 0.5 M HNO3. Recent proposed changes to the process baseline indicate that loading may include a broader range of sodium molarities (2 to 8 M) and higher temperatures (50°C) to alleviate post-filtration precipitation issues. In addition, elution will likely utilize variable-strength recycled nitric acid containing trace amounts of Cs-137. Cesium ion exchange loading and elution curves were generated for a 5 M Na, 2.4E-05 M Cs loading solution traced with Cs-134 followed by elution with variable HNO3 (0.02, 0.07, 0.15, 0.23, and 0.28 M) containing variable CsNO3 (5.0E-09, 5.0E-08, and 5.0E-07 M) and traced with Cs-137. The ion exchange system consisted of a pump, tubing, process solutions, and a single, small (~15 mL) bed of SRF resin with a water-jacketed column for temperature-control. The columns were loaded with approximately 250 bed volumes (BVs) of feed solution at 45°C and at 1.5 to 12 BV per hour (0.15 to 1.2 cm/min). The columns were then eluted with approximately 25 BVs of HNO3 processed at 25°C and at 1.4 BV/hr. The two independent tracers allowed analysis of the on-column cesium interaction between the loading and elution solutions. The objective of these tests was to improve the correlation between the spent resin cesium content and cesium leached out of the resin in subsequent loading cycles (cesium bleed), to help establish acid strength and purity requirements.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1179147
• Report Number(s): PNNL-SA-77254; 830403000
• Country of Publication: United States
• Language: English