Transport of iron(II) across supported liquid membranes (SLM)

A laboratory-scale experiment was conducted to examine the transport of Fe(II) through a supported liquid membrane (SLM) impregnated with tri-n-butyl phosphate (TBP) in toluene. Iron(II) was distributed between hydrochloric acid solutions of different chemical potentials. The membrane consisted of a micro-porus polymeric support wetted with an organic carrier, which was held within the pores by capillary forces. It was observed that the concentration of the organic carrier and the structure of the membrane had a marked effect on the metal flux across the membrane. The flux increased with increasing concentration of the carrier in the membrane, reaching a maximum value at about 40 % carrier concentration (v/v), above which the flux decreased again. This phenomenon was a result of increasing the solubility and viscosity of the organic phase. The model equations developed previously were tested using the experimental data. The inclusion of the viscosity and solubility effects in the model resulted in good predictions of the experimental results.