Modification and Enhancement of Hydrophilicity of Hollow Fiber Polymer Alloy Membranes with Sulfonated Poly (Ether Ether Ketone) for the Treatment of Oil Effluents Using the Membrane Bioreactor Process

Abstract

Water pollution with petroleum compounds is one of the most important environmental problems in oil-rich countries, due to its adverse effect on soil, water, and human beings. The hydrophilic hollow fiber membranes were produced by polymer blending of polyamide imide and sulfonated poly ether ether ketone. Membrane structure and function were investigated by field emission scanning electron microscopy analysis, N2 permeation, overall porosity, collapse pressure, water contact angle, pure water flux tests. A membrane bioreactor system was used for oily wastewater treatment. From FESEM, a more open structure with larger finger-like was observed by increasing the PAI / SPEEK ratio. Using the PAI / SPEEK ratio of 85/15, the water contact angle of the membrane was decreased from 74° to 58° which showed a significant hydrophilicity improvement. From compaction test, pure water flux of the membranes showed a gradual decrease during 2.5 h and then reached a steady state with minimal changes. During a period of about 5 hours of the oil separation through the MBR process, the plain PAI membrane and the blend PAI-SPEEK membrane showed water flux reduction of about 35% and 21%, respectively. Under 5 bar transmembrane pressure and the addition of 30 mg/l of oil spill eater (OSEII) enzyme, the oil concentration decreased from 36 ppm to 1.2 ppm in the wastewater, which represents the oil removal efficiency of about 97%. In this work, the optimum state for oil removal was obtained in terms of adding OSEII and aeration.

Keywords

• blend hollow fiber membrane
• polyamide imide
• sulfonated poly (ether ether ketone)
• membrane bioreactor
• oily wastewater treatment