Mathematical models for emulsion-type liquid membrane were compared and analyzed using the experimental conditions of phenol removal from waste water. Overall extraction rate equation for a single water-in-oil （w/o） emulsion globule was derived under the pseudo-steady state approximation.
By means of the concept of rate controlling step, each proposed model was proved good under each investigator's w/o emulsion preparation conditions, at least.
Some helpful w/o emulsion preparation schemes were proposed for the increase of extraction rate.