Solidification/Stabilization of Pb-contaminated Soils with Cement and Other Additives
Solidification/Stabilization of Pb-contaminated Soils with Cement and Other Additives
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DOI：
10.1080/15320383.2014.890168
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
Y. Xi;Xiaofeng Wu;Hao Xiong
中科院分区：
文献类型：
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作者：
Y. Xi;Xiaofeng Wu;Hao Xiong
在目前的工作中，各种添加剂，包括水泥，石灰，蒙脱石，硅藻土，海泡石，粉煤灰和它们的不同比例，稳定/固化人工制备的铅污染土壤。测定了固化土的无侧限抗压强度，以评估其再生利用的可能性。利用美国环保局TCLP毒性试验评价了Pb 2+在污染土壤中的固定效果。X射线衍射（XRD）和扫描电子显微镜（SEM）分析用于阐明负责重金属的固定化机制。结果表明：42.5#水泥的固化效率明显高于32.5#水泥，且以水泥：粉煤灰：生石灰质量比为2：1：1的添加剂固化效果最好。仅用10%（重量）的添加剂处理后，Pb 2+污染水平为10，000 mg/kg的污染土壤就可以成功修复，这有助于降低修复过程的成本。浸出试验结果与XRD和SEM分析结果一致。
In the present work, various additives, including cement, lime, montmorillonite, diatomite, sepiolite, and fly ash and their various proportions, were employed to stabilize/solidify artificially prepared Pb-contaminated soils. The unconfined compressive strength properties of the stabilized/solidified soils were measured to estimate the possibility of recycling. The efficiency of Pb2+ immobilization in contaminated soils was also evaluated using the US EPA TCLP toxicity test. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses were used to elucidate the mechanisms responsible for the immobilization of heavy metals. The experimental results demonstrate that the immobilization efficiency with 42.5# cement was obviously higher than that with 32.5# cement, and the additives with a mass ratio Mcement:Mfly ash:Mquicklime of 2:1:1 were found to be the most effective. After treatment with only 10% (weight basis) additive, contaminated soil with a Pb2+ contamination level of 10,000 mg/kg could be successfully remediated, which helps to reduce the cost of the remediation process. The results of the leaching tests agreed with those of XRD and SEM analyses.