Selective separation of uranium from nuclear waste solution by bis(2,4,4-trimethylpentyl)phosphinic acid in ionic liquid and molecular diluents: a comparative study

Selective separation of uranium using bis(2,4,4-trimethylpentyl)phosphinic acid in xylene and C8mimNTf2 was investigated. For ionic liquid based system, the extraction kinetics was found to be slower with the predominance of ion exchange mechanism through [UO2(NO3)·2L]+, while for xylene based system solvation mechanism. The nature of the extracted species was found to be different in both the media as observed in luminescence study. Ionic liquid based system was more radioresistant than that of molecular diluents. Na2CO3 was successfully used for stripping. The selectivity was investigated by processing simulated high level waste of pressurized heavy water reactor origin.