Dj. Wood et al., EXTRACTION OF LEAD AND STRONTIUM FROM HAZARDOUS-WASTE STREAMS BY SOLVENT-EXTRACTION WITH 4',4',(5')-DI-(T-BUTYLDICYCLOHEXO)-18-CROWN-6, Solvent extraction and ion exchange, 15(1), 1997, pp. 65-78
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.