Strength and Leachability of Solidified Sewage Sludge with Different Additives
Strength and Leachability of Solidified Sewage Sludge with Different Additives
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DOI：
10.1061/(asce)mt.1943-5533.0000738
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发表时间：
2013-11-01
影响因子：
3.2
通讯作者：
Han, Jie
中科院分区：
文献类型：
--
作者：
Lin, Cheng;Zhu, Wei;Han, Jie
城市污泥的产生和处置由于其力学性能差和环境影响等问题日益受到人们的关注。基于水泥的固化/稳定化可以改善污水污泥的性质，使其可以用作土木建筑材料或填埋场。为了实现这一目标，需要使用大量的水泥，从而增加了处理成本和水泥生产产生的CO2排放。为了减少水泥的使用，三种无机添加剂（例如，钙-膨润土、粉煤灰和高岭石），以提高用水泥固化/稳定污水污泥的效果。这些添加剂对经处理的污水污泥的益处在无侧限抗压强度和污染物（包括碱度、化学需氧量（COD）和重金属（例如，铜、铅和锌）。X射线衍射（XRD）和扫描电子显微镜与能量色散谱（SEM/EDS）进行了检查与这些添加剂产生的处理后的污泥的行为相关的机制。试验结果表明，钙基膨润土是一种良好的水泥添加剂，可以提高水泥固化/稳定污泥的效果。当污泥、水泥与钙基膨润土的质量比为1：0.2：0.2时，处理后污泥的无侧限抗压强度可满足填埋7 d和建筑材料28 d的要求。
Production and disposal of sewage sludge have raised increasing concerns due to their poor mechanical properties and negative environmental effect. Cement-based solidification/stabilization can improve the properties of sewage sludge so that it can be used either as an earth-construction material or landfills. To achieve this goal, a large amount of cement should be used, thus increasing the treatment cost and CO2 emission arising from cement production. To reduce cement usage, three inorganic additives (e.g.,calcium-bentonite, fly ash, and kaolinite) were used and investigated in this study to improve the effectiveness of solidification/stabilization of sewage sludge with cement. The benefits of these additives to the treated sewage sludge were evaluated in terms of unconfined compressive strength and leaching of pollutants including alkalinity, chemical oxygen demand (COD), and heavy metals (e.g.,copper, lead, and zinc). X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) were conducted to examine the mechanisms associated with the behavior of the treated sludge resulting from these additives. The test results show that calcium-bentonite was a favorable additive to improve the effectiveness of cement to solidify/stabilize the sewage sludge. As the ratio of sewage sludge, and cement, to calcium-bentonite by weight reached 1:0.2:0.2, the unconfined compressive strength of the treated sewage sludge could meet the requirement for landfilling at seven days and that of a construction material at 28days.