Diluent effect on Sr(II) extraction using di-tert-butyl cyclohexano 18 crown 6 as the extractant and its correlation with transport data obtained from supported liquid membrane studies Original Research Article

The effect of organic diluents on the extraction of Sr(II) from an aqueous nitrate medium (containing a mixture of 2.0 M Al(NO3)3 + 0.5 M HNO3) using di-tert-butylcyclohexano 18 crown 6 (DTBCH18C6) as the extractant was investigated. The diluent effect on the Sr(II) transport rates across supported liquid membranes (SLM) containing DTBCH18C6/diluent as the carrier was also investigated. Though diluents containing DTBCH18C6 alone have shown moderate transport rates, their 1:1 mixture with 1-octanol has shown significant enhancement in transport rates: a 1:1 chloroform–octanol mixture resulted in the highest distribution ratio values though the transport rates were at maximum with a tert-butyl benzene–octanol mixture. The extractability of the metal ion was correlated with Schmidt’s diluent parameter.