Fate of Dissolved Organic Substance and Filtration Performance in a Membrane Bioreactor.

Fate of dissolved organic substance and filtration performance were observed in a pilot-scale membrane bioreactor from which excess sludge was wasted once a week. During the operation for 300 days, no substantial increase of sludge viscosity and dissolved organic carbon was observed in the bioreactor. Meanwhile the membrane bioreactor was operated without significant membrane fouling. The study, therefore, was concluded that excess sludge wasting was important to maintain good filtration conditions particularly for a long period of time.