Abstract:The activated sludge metabolic features of a low temperature SBR system (7±1)℃ were studied for pollutant removal efficiency, bioactivity, and the sludge feature aspects. The low temperature SBR system removed 96% of COD within 40 minutes during the aerobic phase. The whole operation cycle was beneficial to COD degradation. The nitration process was restrained and the denitrifying process was unable to work normally due to the effect of low temperature. The low temperature was not the key factor that affected the phosphorus metabolic process of poly-P bacteria in the SBR reactor, as the poly-P bacteria could absorb and release the phosphorus normally in the low temperature environment. The TTC(2,3,5-triphenyl-tetrazolium chloride) and INT[2-(p-indophenols)-3-(p-nitro phenyl)-5-phenyl-tetrazolium Chloride] Electron Transport System(ETS) activity can effectively characterize the operation of activated sludge metabolic properties. Sludge in the stable operated low-temperature SBR system showed good settling. MLSS, MLVSS and MLVSS/MLSS in the low temperature SBR system were higher than that in normal temperature SBR system.