中试SBR长期运行中粘性膨胀现象及原因分析

The causes of non-filamentous activated-sludge bulking in a long-term pilot-scale sequencing batch reactor(SBR)

通过对SBR中型试验系统长期(200d)处理实际生活污水过程中的污泥膨胀现象进行考察,研究了温度、污泥中胞外聚合物(EPS)含量、污泥负荷及DO浓度与污泥膨胀现象之间的内在联系.试验结果表明,系统污泥膨胀属于粘性膨胀,是一种在低温(16℃以下)条件下容易发生的污泥膨胀现象,且这种膨胀会导致污泥流失并致使系统混合液污泥浓度(MLSS)逐渐降低至1200mg·L-1.粘性膨胀污泥分泌的EPS水平超过正常污泥,即使在正常DO浓度(2.0mg·L-1)和常温(20℃)条件下,粘性膨胀污泥也较难通过人为控制恢复到正常状态.最后,分析得出粘性膨胀的原因主要是温度突变,并提出相应的预防措施.

Activated-sludge bulking was found in a pilot-scale SBR with long-term operation over 200 days,fed with real domestic wastewater. This paper focuses on the analysis of the relationship between sludge bulking and factors such as temperature,the content of extracellular polymeric substances （EPS）,sludge loading and DO. The results showed that non-filamentous activated-sludge bulking generally occurred at low temperature （16℃）,which led to poor settleability of the sludge. The MLSS of the SBR gradually decreased to less than 1200 mg·L^-1 when non-filamentous activated-sludge bulking was found in the system. The content of EPS in the bulking sludge was higher than that in the normal sludge,and bulking sludge was difficult to recover although DO and temperature were 2.0 mg·L^-1 and 20℃,respectively. Finally,the reasons causing activated-sludge bulking were analyzed and preventive approaches are suggested.