Abstract
One drawback of sewage treatment by membrane bioreactor (MBR) is that it requires high running cost. It is mainly caused by a high strength aeration to remove cake layer on the membrane surface for maintaining a permeate flux. The objectives of this study were to evaluate the effects of adding carrier into a MBR and of aeration velocity by a long-term raw sewage treatment. Three reactors were operated for about 250 days at different conditions; Run 1: aeration velocity 0.4 m/min without carrier; Run 2: aeration velocity 0.2 m/min with carrier; Run 3: aeration velocity 0.4 m/min with carrier. As the results, operation with carrier showed better performance in both nitrogen removal and the maintenance of permeate flux. Results of this study suggest that aeration strength can be greatly reduced by adding carrier into MBR.
