Effect of pH, ionic strength, and temperature on uranyl ion adsorption by poly(N-vinyl 2-pyrrolidone-g-tartaric acid) hydrogels

Poly-electrolyte N-vinyl 2-pyrrolidone-g-tartaric acid (PVP-g-TA) hydrogels with varying compositions were prepared in the form of rods from ternary m ixtures of N-vinyl 2-pyrrolidone/tartaric acid/water. The effect of externa l stimuli, such as the solution pH, ionic strength, and temperature, on ura nyl adsorption by these hydrogels was investigated. Uranyl adsorption capac ities of the hydrogels were determined to be 53.2-72.2 (mg UO22+/g dry gel) at pH 1.8, and 35.3-60.7 (mg UO22+/g dry gel) at pH 3.8, depending on the amount of TA in the hydrogel. The adsorption studies have shown that the te mperature and the ionic strength of the swelling solution also influence ur anyl ion adsorption by PVP-g-TA hydrogels. (C) 2000 John Wiley & Sons, Inc.