[Treatment of municipal wastewater with low C/N ratio using an intermittently aerated membrane bioreactor].

A laboratory-scale intermittently aerated membrane bioreactor was applied to treat synthetic household wastewater characterized with low organic matter and high nitrogen concentration. Experimental results showed that at the condition of HRT 12 h, aeration/non-aeration cycle 30 min/60 min and a very long SRT, more than 90% of COD and close 100% ammonia nitrogen could be removed, and the average removal efficiency of TN was more than 80%, but this treatment process seemed to be not available in phosphorus removal. Nitrification was accomplished quickly and completely in the system. The denitrification appeared to be the rate-limiting step for TN removal in the system. Furthermore, a positive linear correlation between the fouling rate and the MLSS concentration was founded, and the higher the MLSS concentration was, the higher fouling rate was.