Abstract:Based on the performance of a pilot-scale system treating municipal wastewater, the influences of surface loading rate, temperature and the ratio of air to water on a Biological Aerated Filter (BAF) are investigated in this paper. The results show that the temperature of wastewater should keep above 15℃. When the surface loading rate reaches as high as 3.0 m3/(m2·h) with the temperature of 20℃, the effluence concentration of SS, COD and NH4+-N could still keep below 15 mg/L, 60 mg/L and 18 mg/L, respectively. It is reasonable to adopt a ratio of air to water of 3.0 when the BAF is used to treat municipal wastewater.