干湿循环条件下固化污泥的物理稳定性研究

针对采用水泥和膨润土为固化材料处理的污水厂污泥为研究对象，采用干湿循环试验测量了在水分强烈变化下固化体的质量、体积、含水率及强度等参数的变化情况，进而评价固化污泥的干湿耐久性。结果表明，水泥的掺入是提高固化体干湿耐久性的主要因素，但要达到一定的掺入量才能发挥作用。膨润土对固化体的干湿耐久性影响呈现两面性，适当地掺入膨润土有利于干湿耐久性的形成，而过多地掺入膨润土反而不利于干湿耐久性的形成。在水泥掺入质量比小于或等于0.4时，干湿循环后固化体相对控制样强度明显提高，但体积显著减小，而水泥掺入质量比大于0.4时，干湿循环后固化体相对控制样强度有所下降而体积基本不变。

Study of wet and dry properties of solidified sludge

Based on the cement-solidification of sludge using bentonite as additive, the wet and dry test was conducted to measure the parameters of relative mass loss, volume change, water content and unconfined compression strength(UCS) under the condition of violent water changes, in order to evaluate the wet and dry durability of the solidified sludge. The results show that the cement plays the major role in improving the wet and dry durability of solidified sludge; and the results are achieved at the enough cement content. Bentonite can also improve the wet and dry durability of solidified sludge at the appropriate range of adding content, however exceeding the range, can reduce the wet and dry durability. At cement content below 0.4, UCS of solidified sludge increases after wet and dry cycles relative to control samples but volume of solidified sludge decreases remarkably; at cement content larger than 0.4, UCS decreases relative to control samples and volume varies little.