DEMULSIFICATION OF WATER-IN-OIL EMULSION BY USING POROUS-GLASS MEMBRANE

The hydrophilic porous glass membranes were used to demulsify water-in -oil emulsion, and demulsification efficiency can reach more than 96.2 %. Effects of pore size of the membrane, transmembrane pressure and vo lumetric ratio of oil phase to internal aqueous phase in the emulsion on demulsification were investigated. It was found that pore size of m embrane and transmembrane pressure can significantly affect demulsific ation efficiency. The smaller the pore size of the membrane, the bette r the demulsification efficiency. However, smaller pore size of the me mbrane has to be exerted a greater transmembrane pressure in order to make internal aqueous phase enter the membrane pore. Correspondingly, effect of transmembrane pressure on permeation flux of the droplets wa s also studied. In addition, recovered-oil phase by the demulsificatio n were reused five times to extract cadmium from simulated aqueous was te. The results indicated that the extracting efficiency could arrive at 96.5%. (C) 1998 Published by Elsevier Science B.V. All rights reser ved.