Distribution Coefficients of Polonium Between 0.75 M HDEHP in Cyclo- hexane and Aqueous Hydrochloric and Nitric Acids

The distribution coefficients (D) of polonium between 0.75 M di(2-ethyhexyl)phosphoric acid (HDEHP) in cyclohexane and aqueous hydrochloric and nitric acids have been studied. Results indicate that: (1) D values are ranged from 32.7 to 0.00048 when the HCl acidities vary from 0.10 to 10.0 M, showing that polonium can well be extracted by 0.75 M HDEHP in cyclohexane if the aqueous HCl acidities are 0.050 M and it will not be extracted if 0.10 M HCl; (2) D values are ranged from 47.1 to 0.0117 when the HNO3 acidities vary from 0.10 to 10.0 M, showing that polonium can be extractable by 0.75 M HDEHP in cyclohexane and in a wide range acidity of 4 M HNO3. The different extraction behaviours of polonium in 0.75 M HDEHP in cyclohexane and different acidities of HCl and HNO3 were found. The findings will be very helpful to improve the methods involving polonium decontamination for determination and separation of americium, curium as well as other radioelements in environmental soil, water and biological samples.