Non-dispersive solvent extraction with strip dispersion (NDSXSD) pertraction of Cd(II) in HCl medium using ionic liquid CYPHOS IL101

Abstract

The transport of Cd(II) from hydrochloric acid medium in NDSXSD technology is investigated using the ionic liquid CYPHOS IL101 (tetraalkyl)phosphonium salt) dissolved in cumene as carrier phase. The permeation of the metal is investigated as a function of various experimental variables: hydrodynamic conditions, concentration of cadmium(II) and HCl in the feed phase, carrier concentration, support characteristics, etc. In NDSXSD, a pseudo-emulsion is temporarily formed between the organic and stripping solutions. The overall mass transfer coefficient (K=4.1×10-3cms-1) and the thickness of the aqueous boundary layer (daq=1.8×10-3cm) were calculated from experimental data. Of the different reagents used, 1M ammonium hydroxide served most efficiently as the stripping agent. Furthermore, the selectivity of CYPHOS IL101-based membrane towards different metals is investigated, whereas the system is compared with other carriers in the liquid membrane phase. © 2011 Elsevier B.V.