The performance of the SuperLig ® 644 resin loading and elution was evaluated at 25, 35, and 45 o C using a single-column (1.54-cm i.d.) containing 2.25 g of oven-dry, hydrogen form of SuperLig ® 664 resin. A simulated Envelope A solution was used to mimic the composition of low-activity waste solution from Tank 241-AN-105 supernate in the Hanford Site waste tank. The simulant was spiked with small quantities of trace metals (cadmium, chromium, iron, and lead) to evaluate the effects of these metals on cesium sorption. The results from column tests performed at 25, 35, and 45 o C showed that more than 100 BVs of simulated Envelope A solution could be processed at each temperature before 50% breakthrough of the cesium occurred. The breakthrough capacity of the resin at the breakthrough point (i.e. 50% C/Co) was 0.015, 0.013, and 0.011-mmole/g of oven-dry resin for the temperatures 25, 35, and 45 o C, respectively. The performance of the cesium column loading before and after resin exposure to elevated temperatures had not changed, thus showing no evidence of thermal degradation. Elution of the resin at elevated temperatures (35 and 35 o C) had not speeded up cesium elution or reduced eluent consumption. Elution of the resin with 0.5M nitric acid was generally effective at all temperaturs, requiring only 10 BV to reduce cesium concentration to below 1% of initial feed concentration. Cesium uptake by SuperLig ® 644 resin increased with increasing resin particle size. A 2.5-fold increase in cesium K d value was observed for resin particle size range (590-840 µm) versus (250-420 µm) after 72-h contact with AN-105 simulant. Although the results were unexpected, the data agreed with results (cesium K d values vs. particle size) reported by the resin manufacturer (IBC Advance d Technologies) for a different batch of SuperLig® resin. The uptake of trace metals such as cadmium, chromium, iron, and lead by the SuperLig ® 644 resin was noted. In the absence of cesium, SuperLig® 644 resin showed slight affinities for these trace metals. The affinity increased in the sequence iron> cadmium> lead> chromium. Since the concentrations of these minor competitors in the Hanford Site waste tanks are low, it is unlikely they will have a significant impact on cesium sorption of the resin. The SuperLig® 644 resin degraded when stored in simulated Envelope A solution for 15 days at 45 o C and not protected from air; upto 50% mass loss of the resin was observed. The mass loss of the resin when protected from air oxidation (i.e. stored under nitrogen) was 5-10% under the same experimental conditions. The morphology of resin protected from air oxidation appeared to be unchanged. The resin retained characteristic sharp edges and rough surface normally observed for unexposed, but pretreated SuperLig ® 644 resin. In contrast, resin stored in simulated Envelope A solution with air headspace showed damage to particle morphology as indicated by significant smoothing of the rough edges with signs of extensive cracking.
