| Recent advancement in membrane technology, especially in micro- and ultra-filtration, has given an impetus to the development of membrane bioreactors for various wastewater treatments. A membrane bioreactor, a combination process of biological reactor coupled with membrane separation, is regarded as innovative technology for wastewater treatment and reclamation. The process has many advantages, such as excellent and stable effluent quality, compact equipment, high volumetric load and less surplus sludge production. For these reasons, studies on the application of membrane bioreactor in treating domestic wastewater are very important.In this paper, domestic wastewater were treated in a pilot-scale submerged membrane bioreactor . It had an initial CODcr averaged 200mg/L and NH3-N average 20mg/L. The hydraulic residence time (HRT) was 4. During the pilot experiment, surplus sludge was not removed, so the sludge residence time (SRT) was very long. The biomass concentration ranged from 5000mg/L to 6000mg/L. Dissolved oxygen concentration (DO) was 3. 7mg/L. Under the conditions of transmembrane pressure 0. 073MP, membrane flux 80L/h and air flow rate 150L/min, the results showed that average removal rate of CODcr and NH3-N is more than 90% respectively. In most of time, rate of both are 95%. By this process, the effluent was stable and could be reused for washing and so on.The submerged membrane bioreactor has the potential to be applied to small wastewater treatment plants and it will bring us new and beautiful life and environment.
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