Ion exchange project

The project objective was to design an ion exchange column to remove 71 ppm Sr2+ from a 21,300 gal/day toxic waste stream and estimate the annual NaCl requirement to regenerate the resin. Ion exchange was modeled using calcium and was tested with an Aquarium Pharmaceuticals, Inc. divalent cation test kit. The test kit is not suitable for field use due to inaccuracies and strict removal specifications. A 640 ppm Ca2+ solution at 100 mL/min flowed down the column filled with 30 mL of Ionac C-249 resin and samples were collected every 3 minutes for 45 minutes. Calcium concentrations were determined for each sample to create a breakthrough curve to calculate exchange capacity. Exchange capacity of virgin resin was 2.8 Eq/L, 47% larger than the accepted value of 1.9 Eq/L. Regeneration efficiency of 41% was estimated using 6 L of a 6000 ppm NaCl solution at 150 mL/min. Twelve samples were collected over 40 min and Ca2+ concentrations were calculated. The proposed design requires three columns with diameters of 45 cm, heights of 7.5 m, and resin heights of 5.6 m. Annual NaCl requirements for daily regeneration of proposed design is 14,000 kg