污水厂污泥固结特性研究

污水厂污泥难以脱水减量已成为污水处理行业的重要问题,机械脱水的本质就是污泥的固结排水过程,因此通过固结试验研究污泥的固结特性,对于进一步提高脱水效率具有重要意义。在固结试验过程中采用何种固结稳定判定标准,对污泥固结特性的研究具有非常重要的影响。通过对固结仪进行改进增加孔压计和位移传感器,对2种污水厂污泥和1种湖泊淤泥进行了试验,研究了他们固结特性的区别。结果表明:污泥的固结时间非常长,应将超净孔隙水应力消散到3%作为固结稳定标准;污泥的固结系数与渗透系数非常小,且随着固结压力的增大而减小非常明显。同时通过分析,认为污泥中存在的大量有机物絮体是造成污泥固结时间非常长、水分难以排出的主要原因。

Consolidation properties of dewatered municipal sewage sludge

The difficulty of sewage sludge dewatering has become one of significant issues in sewage water treatment industry. The essence of mechanical dewatering of sludge is a process of consolidation and drainage; therefore, the investigation of the consolidation behavior of sludge by consolidation experiment is important to the enhancement of dewatering effects. Select different consolidation stability standards has the very important influence on research of consolidation properties of sludge. Based on the improvement of oedometer by setting additional piezometer and displacement sensor, two types of sewage sludge and one type of dredged materials were studied for their difference of consolidation characteristics. The results indicated that consolidated time of sludge was very long and its finishing was supposed to be determined by the time when excess pore water pressure dissipated to 3% of consolidation pressure. The coefficient of consolidation and coefficient of permeability of sludge is extremely low, and have great changed in the consolidation process . Meanwhile, the main reason of very long time consolidating and hard for drainage is a large number of organic matter flocs in sludge.