Modification of membrane formulation for stabilization of emulsion liquid membrane for extraction of phenol from aqueous solutions

In this study, the removal of phenol from aqueous solutions by a stabilized emulsion liquid membrane (ELM) has been investigated. The emulsion formulation was modified by the addition of a rubbery polymer (Styrene Butadiene Rubber, SBR) and then the resultant emulsion was dispersed in the external phase. The effect of various parameters such as pH of the external phase, internal phase reagent concentration, phase ratio, temperature and intensity of dispersion was studied. A stable emulsion liquid membrane system was obtained by the addition of 3 wt.% of SBR to the membrane phase at 30 °C with an agitation speed of 210 rpm. The addition of SBR to the membrane phase increased the stability of the emulsion liquid membrane from 5 to 35 min, which is ideal for ELM operations. In general, the results showed that by increasing the volume ratio of emulsion phase to feed phase (Rew), internal phase reagent concentration and decreasing feed pH, the extraction efficiency increases. The best extraction efficiency was obtained at the internal phase reagent concentration of 5000 mg/L, pHF = 1.0, Rew = 0.2, agitation speed of 210 rpm, initial phenol concentration of 100 mg/L and at 30 °C while the emulsion was contained at 3 wt.% of the SBR polymer. In this condition, the maximum extraction efficiency of 90.1% was obtained within less than 35 min.