Sorption and transport of Cs-137, Sr-90 and Co-60 radionuclides by polymer inclusion membranes

Plasticized cellulose triacetate membranes with dinonylnaphthalenesulfonic acid (DNNS) as the ion carrier containing 2-nitrophenyl pentyl ether as the plasticizer were synthesized for competitive transport and sorption of Cs-137, Sr-90, and Co-60 radioisotopes from aqueous solutions of sodium nitrate at concentration of 1.0×10−7 mole/dm3 each. The selectivity order of metal cations transported was found to be: Co(II) > Cs(I) >Sr(II) > Na(I). The highest distribution coefficients for isotopes studied in the sorption process were received at 0.50 mole/dm3 DNNS in the polymer inclusion membrane. For the sodium nitrate concentration higher than 0.010 mole/dm3 a significant decrease of isotopes distribution coefficients was found. For high concentration of sodium nitrate, i.e. 0.10 mole/dm3, we transported isotopes across the polymer inclusion membrane with a high ratio of source/receiving phase, i.e. equal to 100. After 72 h of transport we received the Co(II) concentration factor and recovery factor equal to 9.2 and 95%, respectively. On the other hand, Sr(II) was removed with the recovery factor equal to only 50%.