SEPARATION OF U, Th AND RADIONUCLIDES BY TNOA EXTRACTION COLUMN CHROMATOGRAPHY

The adsorption coefficients of uranyl ions between TNOA-treated polyvinyl chloride (PVC) powder and hydrochloric acid have been measured in batch experiments. It has been found that the effect of the concentration of TNOA in the stationary phase and the concentrations of HC1 and LiCl on the adsorption coefficient of uranyl ions were similar to the liquid-liquid extraction in the TNOA-HC1 system. The adsorption capacity of TNOA treated PVC powder increased on increasing the concentration of uranyl ions in aqueous solution and followed the Freundlish adsorption equation. The effect of y-radiation on the adsorption capacity of TNOA-treated PVC powder has also been described.The separation of U, Th and radionuclides by TNOA column extraction chromatography has been studied. Microgram uranium can be completely separated from a bulk amount of thorium by TNOA-PVC column with 7.5M HC1 as the eluent. Such a column was also applied to the separation of U, Th and other long-life fission products.