Study on the application of membrane technology and performance of nanostructured polyethersulfone (PES) hollow fiber membrane in treatment of oily wastewaters

Nowadays, oily and industrial wastewaters are among the most important environment problems. Conventional methods can hardly reduce the oil content to 1% of the initial concentration and are not able to effectively remove the oil droplets with the size less than 20 micrometer. Therefore, oily wastewater treatment is one the most essential environmental challenges which should be resolved in the oilfields.
In this study, the performance of different membranes in oily water treatment has been reviewed and furthermore, the performance of nanostructured polyethersulfone (PES) hollow fiber membranes in oil/water separation process has been investigated.
Findings: The membrane performance would change with time according to the membrane type, the feed compositions and the process conditions. In this research, the effects of operating parameters such as pressure, oil concentration and cross flow velocity of feed on the membrane performance were studied. Increase of pressure makes more membrane compactness and higher membrane fouling which reduce the performance. Therefore, the optimum operating conditions for oil separation are P = 1 bar, low feed concentration and high cross flow velocity of feed. Due to the increase of mass transfer at high feed flow rates, oil rejection reduces slightly.
All the PES membranes in this study showed complete separation of oil from water and can effectively be used in oily water treatment process.