EXTRACTION OF LEAD AND STRONTIUM FROM HAZARDOUS-WASTE STREAMS BY SOLVENT-EXTRACTION WITH 4',4',(5')-DI-(T-BUTYLDICYCLOHEXO)-18-CROWN-6

Extraction of Pb from nitric acid solutions and simulated acidic hazar dous waste streams has been demonstrated with 0.15 M 4',4',(5')-di-(t- butyldicyclohexo) 18-crown-6 and 1.2 M tributyl phosphate in a commerc ial isoparaffinic hydrocarbon called Isopar L(.). The extraction has b een shown to be dependent upon extractant concentration, aqueous nitra te concentration, and the identity of the predominant anion in the aqu eous phase. It has been shown that Pb and Sr can be extracted simultan eously and stripped efficiently from the loaded organic phase. The qua ntitative (> 99 %) removal of Pb and Sr can be achieved in 3 to 4 batc h contact extractions. Batch contact flowsheets have been utilized to demonstrate the potential for the simultaneous removal of Sr and Pb fr om simulated radioactive waste followed by partitioning of the extract ed Sr fraction from the Pb fraction.