Facilitated transport of tetravalent plutonium from nitric acid medium using a novel extractant – BenzoDODA

• Efficient transport of Pu(IV) from nitric acid medium using 0.1 M BenzoDODA.
• Negligible transport of other elements present in high level waste.
• Diffusion co-efficient of Pu(IV)–BenzoDODA was determined to be 7.52 × 10−7 cm2/s.
• The SLM was found to be stable over six cycles of operation.

Facilitated transport of Pu(IV) from nitric acid medium was studied using a novel extractant, BenzoDODA in supported liquid membrane mode. BenzoDODA is a highly selective ligand for Pu(IV), providing very high decontamination factor from other fission products present in high level waste (HLW) solution (nitric acid medium). Various process parameters such as feed acidity, concentration of BenzoDODA, membrane pore size etc., were optimized to achieve effective transport of Pu(IV). Near quantitative (∼97%) transport of Pu(IV) was observed in ∼360 min using 0.1 M BenzoDODA as carrier in n-dodecane employing 0.45 μm PTFE as membrane support when 0.2 M N2H4 in 0.6 M HNO3 was used as strippant. Transport studies with diluted HLW of PUREX origin showed near negligible transport of other elements present in the solution when near quantitative transport of Pu(IV) was observed. The maximum permeability coefficient (P) value was found to be 2.50 × 10−4 cm/s at 3.85 M HNO3 as feed acidity using 0.1 M BenzoDODA as carrier. The membrane was found to be stable over six cycles of operation. Thus, this system can be used for separation of Pu(IV) from acidic process streams.

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