中文摘要：

在以A^2／O方式运行的SBR中，采用人工废水研究了温度降低再升高过程中污泥沉降性能的变化。结果表明，一旦反应器水温由25℃以上降低到15℃以下，污泥就会发生膨胀，当再升温至25℃以上时，污泥膨胀消失，污泥沉降性能恢复到良好状态。在降温一温度恢复的这一过程中，污泥沉降性能恢复所花费的时间比发生膨胀所需的时间长。降温对可导致污泥膨胀的微生物的促进作用要比升温对该微生物的抑制作用、对菌胶团的促进作用显著。在温度波动过程中，当系统发生的是单一高粘性膨胀时，污泥沉降性能恢复时间是污泥膨胀发生时间的2倍；当系统发生的是丝状膨胀和高粘性膨胀并存的污泥膨胀时，污泥沉降性能恢复时间是污泥发生时间的9倍。在降温波动过程中，污泥沉降性能恢复时间与系统内存在的丝状菌种类有关，当污泥膨胀发生后系统中存在能适应低温环境并生长的丝状菌时，污泥沉降性能恢复时间就较长，但这有利于恢复后形成密实的污泥絮体。

英文摘要：

The variation of sludge settleability during temperature fall and rise was investigated using synthetic wastewater in SBR operated in A2/O mode. The results show that once the water temperature in the reactor decreases from above 25 ℃to below 15 ℃ , the sludge is bulked, but the bulking disappears, and the sludge settleability recovers to a normal state when the temperature rises to above 25 ℃ again. The recovery process of sludge settleability needs more time than the process of sludge bulking. The effect of temperature fall on growth stimulation of sludge bulking microbes is more significant than that of temperature rise on growth inhibition of sludge bulking microbes and growth stimulation of zoogloea. When non-filamentous sludge bulking takes place in the system during fluctuation in temperature, the recovery time of sludge settleability is twice longer than that of sludge bulking occurrence. While filamentous sludge bulking and non-filamentous sludge bulking occur simultaneously in the system, the recovery time of sludge settleability is 9 times of that of sludge bulking occurrence. The recovery time of sludge settleability is related to filamentous bacteria in the at low temperatures exist in the system after sludge needs a longer time, but it is helpful to form dense system. When the filamentous bacteria that can grow bulking, the recovery process of sludge settleability sludge floc after the recovery.