The instant invention relates to novel liquid membrane formulations, i.e., emulsions, which comprise an aqueous interior phase and a water-immiscible exterior phase; said water-immiscible exterior phase comprising an ethylene vinyl acetate copolymer and a solvent for this polymer. These compositions may additionally contain a water insoluble surfactant to stabilize the emulsions. In the most preferred embodiment, the aqueous interior phase comprises a strong acid, for example from about 1 to 10 percent by weight sulfuric acid. These emulsions are useful in liquid membrane processes for the separation of dissolved components from aqueous solution. Emulsions of the instant invention are characterized as showing very low swelling when contacted with aqueous solutions, especially at higher temperatures and thus are especially effective for use in the treatment of sour water feed streams by the liquid membrane technique.