污泥脱水方法及其物理力学效应

A sludge dehydration method and its physical mechanical effects

以传统水泥固化污泥的研究为基础,提出预压法降低污泥初始含水率,以期使室内制备试样与实际相吻合。通过系列室内试验对比发现,由于预压法保留原始污泥有机质,其液塑限均高于烘干法。两种方法的应力—应变曲线表明:烘干法破坏应变在6.1%,为脆性破坏模式;预压法破坏应变在3.7%,为塑性破坏模式。烘干法初期强度增长较快且后期强度趋于稳定;在固化剂胶结作用与腐殖酸的缓释—侵蚀协同作用下,预压法初期强度增长缓慢,胶结作用大于侵蚀作用。养护至120 d后强度逐渐降低,侵蚀作用大于胶结作用。

Based on the study of traditional cement-improved sludge ,preloading was used to reduce the initial water content of sludge, and sludge samples prepared indoor could be taken as nature soil. Various laboratory tests were carried out and compared with one another. The results show that liquid and plastic limits of the samples under the preloading method are higher than that of the samples under the drying method, which is due to the reservation of organic matter in the former one. Moreover,stress-strain curves indicate that the failure strain of the samples under the drying method is 6. 1 %,which belongs to brittle failure ,while the failure strain of the samples under the preloading method was 3. 7 % , which can be regarded as plastic failure. The initial strength of the samples under the drying method increases rapidly while the long-term strength is s table. As for the preloading method, the initial strength of the samples grows slowly due to the synergy of cementation and release-erosion of organic matter,and the effect of cementation is larger than that of erosion. However, after curing for 120 days ,the strength of the samples decreases gradually,and the effect of erosion on them is larger than that of cementation.