Development of low level liquid waste treatment systems: April-September 1981

The pilot plant reverse osmosis system was demonstrated to be effective in removing large percentages of cobalt-60, iodine-125, and a mixture of cesium-137, cobalt-60, and iodine-125 from two types of aqueous streams. The effectiveness of three membrane porosities, 0, 50, and 97% salt rejection, were explored with each isotope. The 97% salt rejection membrane was the most effective in each experiment. Removals as high as 97.5% of the cobalt, 92.9% of the iodine and 95.1% of the combined isotopes were achieved. The effect of possibly interfering factors on the adsorbence of cobalt-60 and iodine-129 on selected ion exchange resins were investigated. The factors thought to affect cobalt-60 adsorption were (OH/sup -/), (NH/sub 4//sup +/), and (SO/sub 3//sup =/). None of the seven factors investigated had any effect on iodine-129 adsorption. Cesium-137 was removed from a 4600-gal aqueous waste containing a large amount of sodium hydroxide by treatment with sodium tetraphenyl boron. The cesium concentration of the supernatant portion was reduced from 570 to 4 counts/min/ml