Colloidal gas aphrons (CGAs) are special bubbles which are prepared from a very low concentration of surfactant with applying high shear force. Two specific features of CGAs are their micro sizes and relative high stability relative to conventional bubbles. These features make them to be used in various applications such as separation of small size particles from water and waste water, emulsions purification, and even in oil drilling operation. In this thesis, separation of diesel oil impurities by aphron from water has been investigated. To achieve this aim, the effect of diesel oil concentration, sodium lauryl sulfate surfactant concentration and mixing time on separation of oil impurity has been examined by experimental design method. Experimental results show that a) Separation efficiency increases with concentration up to 745 ppm and then decreases. b) The effect of surfactant concentration on separation efficiency is negligible. c) Efficiency enhances with mixing time up to 5 min. and then falls. Keywords : Colloidal gas aphrons, Stability of aphrons, Sodium lauryl sulfate,Design of experiment, Diesel oil concentration, Surfactant concentration, Mixing time
