Effect of electrical field on demulsification of water in oil emulsion in emulsion liquid membrane process / by Norasikin Othman, author, Siti Nazrah Zailani, 1985-, author, Norlisa Mili, 1985-, author, Azfar Ahmad, author, Azwadi Piramali, author, Symposium of Malaysian Chemical Engineering (23rd : 2009 : Sabah)