Emulsion Liquid Membrane extraction Cs(137) and Sr(85) by 18 C6 in Xylene from Picrate/Nitrate Medium Promoted by Sulfuric Acid and Analysis of Transport Rates

The effect of picric acid on separation and preconcentration of radioactive fission products (Cs137, Sr85) from a feed of slightly acidic nitrate solution was investigated using emulsion liquid membrane (ELM) technique. A crown ether (18C6), diluted by xylene was used as a carrier (extractant), SPAN 80/85 as a surfactant and dilute sulfuric acid as a stripping agent in the interal phase. The different parameters affecting the permeation process were studied. The prepared ELM showed a high stability (∼3 months) when using in low radioactive waste solutions. The rate of premeation of the investigated radioactive elements was found to depend on H2SO4 solution as a stripping phase (0.3 min-1). The yield of recovery readied about 98% and 60% for Cs137 and Sr85 respectively. The effect of picrate in feed on the rate of permeation was found to be 0.13 cm-1 while for membrane (18C6) was found to be 0.08, min-1. At equilibrium this system can be used for preconcentration equilibrium, while after five minutes Cs137 can be separated from Sr85 kinetically