Role of diluent on the separation of 90Y from 90Sr by solvent extraction and supported liquid membrane using T2EHDGA as the extractant

The separation behaviour of 90Y from 90Sr was investigated by diluent variation using solvent extraction and supported liquid membrane techniques employing N,N,N′,N′-tetra-2-ethylhexyldiglycolamide (T2EHDGA) as the extractant. Both DY (distribution ratio of Y(III)) and S.F. (separation factor) were found to be high in the solvent extraction studies when chloroform was used as the diluent. Subsequent supported liquid membrane (SLM) studies using PTFE flat sheet membranes containing 0.2 M T2EHDGA in various diluents indicated the trend of Y transport as xylene>hexone>chloroform>carbon tetrachloride>n-dodecane+30% iso-decanol mixture. However, the Sr(II) transport rates were also high with xylene, hexone, and carbon tetrachloride as the diluents which led us to carry out subsequent studies using chloroform and n-dodecane+30% iso-decanol mixture. Acid variation studies in chloroform system indicated an interesting phenomena of increasing Y(III) transport and decreasing Sr(II) transport with increasing acid concentration. Separation of 90Y from a mixture of 90Sr and 90Y was also attempted.

► SLM studies using PTFE flat sheet membranes containing T2EHDGA as carrier was carried out for Y-90 separation from Sr-90. ► The trend of Y transport as xylene>hexone>chloroform>carbon tetrachloride>n-dodecane+30% iso-decanol mixture. ► Acid variation studies in chloroform system indicated an interesting phenomena of increasing Y(III) transport and decreasing Sr(II) transport with increasing acid concentration. ► The present studies suggested that T2EHDGA-SLM show limited promise if coupled to another separation method such as extraction chromatography.