Active transport of cobalt (II) through a supported liquid membrane using the mixture DP8R and Acorga M5640 as extractant

Abstract

The facilitated transport of Co(II) from sulphate media through a flat-sheet supported liquid membrane is investigated, and whereas the mixture DP8R and Acorga M5640 extractants is used as ionophore, several experimental variables such as hydrodynamic conditions, concentration of cobalt (II) (0.01-0.16g/L) and pH variation (2.75-9.75) in the feed solution, carrier concentration (1-20% v/v, each) and diluent in the organic phase and strippant concentration (12-50g/L H2SO4) in the receiving phase, are investigated. A model to describe the transport of cobalt (II) is presented, it consists of diffusion through a feed diffusion layer, a fast interfacial chemical reaction, and diffusion of carrier and its metal complex through the organic membrane. From experimental results, the thickness of the aqueous diffusion layer is calculated as 1.9×10-3cm. On the other hand, the mass transfer resistance in the feed phase is estimated as 188s/cm, however, the evaluation of mass transfer resistances indicated that the rate-controlling step of the transport process depends upon the experimental condition considered. © 2011 Elsevier B.V.