Membrane treatment of oily wastewater from refinery processes

Oily wastewater is produced in oil refining processes. This waste is usually treated by a number of physical, chemical, and biological techniques in water treatment units of oil refinery before being disposed in environment or reused as agricultural water. One of the treatment techniques for oil separation from wastewater is membrane filtration. This paper presents the performances of hydrophilic microfiltration (MF GRM) and ultrafiltration (UF GRM) polymeric membranes challenged with synthetic feed (gas oil dispersed in water) and oily wastewater effluent of American Petroleum Institute unit in refinery. A comparison was carried out under optimum conditions and in cross-flow mode in laboratory scale. The effects of operating parameters (i.e. pressure and cross-flow velocity) on flux and rejection were elucidated. The flux of MF GRM membrane for real feed within the first 2h of filtration was low compared with synthetic feed because of the presence of solid and colloidal particles in the real feed. The oil rejection (around 99%) for synthetic feed was higher compared with real feed. Similar trend was found for both UF GRM and MF GRM membranes. (c) 2012 Curtin University of Technology and John Wiley & Sons, Ltd.