给水厂污泥固化制备路基回填材料机理与性能

Mechanism and Performance of the Solidification of Water Treatment Plant Sludge for Subgrade Backfill Material Preparation

摘要:

通过开展无侧限抗压强度、物相与微观形貌分析和重金属含量测定等试验,研究了有机质含量、固化材料类型对给水厂污泥固化改良效果的影响.结果表明:有机质对水泥和污泥固化剂均有显著抑制作用,污泥固化剂固化污泥7d强度为水泥固化污泥的3.0~4.2倍,28d龄期时为3.1~4.5倍,污泥固化剂相比水泥生成了更多钙矾石晶体对污泥颗粒间隙挤密填充,结合水化硅酸钙凝胶对污泥颗粒胶结作用,显著提高了固化污泥微观结构,且对污泥中重金属稳定效果更佳,固化污泥作为路基回填材料强度满足规范要求,污染风险低.

Abstract:

Through experiments such as unconfined compressive strength tests, phase and microstructure analyses, and heavy metal content measurements, the effects of organic matter content and types of solidification materials on the solidification improvement of water treatment plant sludge were investigated. The results show that organic matter had a significant inhibitory effect on both cement and sludge solidifier. The 7-day strength of sludge solidified with sludge solidifier was 3.0–4.2 times that of sludge solidified with cement, and at 28 days, it was 3.1–4.5 times higher. Compared with cement, the sludge solidifier generated more ettringite crystals that densely filled the gaps between sludge particles. Combined with the cementing effect of calcium silicate hydrate gel on sludge particles, it significantly enhanced the microstructure of the solidified sludge and shows a better stabilization effect on heavy metal in the sludge. Moreover, using the solidified sludge as subgrade backfill material meets the requirement