Effect of calcium oxide (CaO) and sawdust on adhesion and cohesion characteristics of sewage sludge under agitated and non-agitated drying conditions
Effect of calcium oxide (CaO) and sawdust on adhesion and cohesion characteristics of sewage sludge under agitated and non-agitated drying conditions
复制标题
搅拌和非搅拌干燥条件下氧化钙（CaO）和锯末对污水污泥粘附和内聚特性的影响
DOI：
10.1016/j.watres.2016.12.001
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发表时间：
2017
期刊：
影响因子：
12.8
通讯作者：
Su Yaxin
中科院分区：
文献类型：
--
作者：
Deng Wenyi;Yuan Minhao;Mei Jing;Liu Yajun;Su Yaxin
污泥干化过程中普遍存在粘滞现象。通过专门为污泥设计的无搅拌和搅拌干燥试验，对污泥的粘性特性进行了论证和比较。研究了添加剂CaO、细木屑（FSD）和粗木屑（CSD）对污泥粘附性和内聚性的影响。结果表明，不同测试方法下污泥的粘性有明显差异，CaO或锯末的添加对污泥的粘性也有很大影响。例如，在非搅拌干燥试验中，CaO可以显着提高污泥的最大粘附应力和内聚应力，而在搅拌干燥试验中，搅拌扭矩，这与污泥的内聚应力密切相关，降低了CaO的添加。在搅拌干燥过程中，添加CaO的污泥块在含水率高于原始污泥时开始破碎。另一方面，锯末对污泥粘性的影响与CaO完全不同。添加5-10%WS（湿污泥基准）的锯末后，由于污泥内部机械联锁的加强，污泥的内聚应力显著增加，而锯末的添加降低了污泥的粘性。本文详细讨论了不同试验方法下CaO和锯末的影响机理。
Stickiness phenomenon is widely observed in sewage sludge drying practices. This paper is aimed at demonstrating and comparing the sticky properties of sewage sludge through non-agitated and agitated drying tests specially designed for sewage sludge. Special attentions were paid to the effects of additives, i.e. CaO, fine sawdust (FSD) and coarse sawdust (CSD), on the adhesive and cohesive characteristics of sewage sludge. The results indicated that the sticky properties of the sludge were markedly different under the different testing methods, and was also greatly influenced by CaO or sawdust addition. For instance, in the non-agitated drying tests, CaO can significantly enhance the maximum adhesive and cohesive stresses of the sludge, whereas in the agitated drying tests, the torque of agitation, which strongly correlated with the cohesive stress of the sludge, was lowered by CaO addition. During agitated drying process, sludge lump with CaO addition started to break up at higher moisture content than that of original sludge. On the other hand, sawdust also affected the sticky properties of sludge in a way that was totally different with CaO. After sawdust addition (at 5–10%WS (wet sludge basis)), the cohesive stress of the sludge was markedly increased due to strengthening of mechanical interlocking inside the sludge, whereas the adhesiveness of the sludge was lowered by sawdust addition. The influencing mechanisms of CaO and sawdust under the different testing methods were detailedly discussed in the paper.