酸溶液淋溶作用下重金属污染土固化体浸出特性及机理

李江山; 王平; 张亭亭; 黄茜; 薛强

doi:10.11779/CJGE2017S1027

酸溶液淋溶作用下重金属污染土固化体浸出特性及机理 English Version

中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉 430071

基金项目: 国家自然科学基金项目（51625903,41602315,51479194）; 中国科学院学科交叉与合作创新团队项目（Y426011C01）; 武汉市高新技术成果转化及产业化项目 (2013060803010403); 岩土力学与工程国家重点实验室资助课题（Z015003）

详细信息

作者简介:
李江山(1987-),男,博士,主要从事污染土多相体作用效应与修复技术研究。E-mail:ljs_cersm@163.com。

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出版历程
- 收稿日期: 2016-11-27
- 发布日期: 2017-11-19

Leaching characteristics and mechanism of heavy metal in solidified/ stabilized contaminated soil under acid solution soaking

State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China

摘要

摘要: 采用KH₂PO₄—水泥复合材料对铅污染土进行固化/稳定化处理,为了研究酸雨淋溶对铅污染土固化体浸出特性的影响规律及其机理,开展了不同KH₂PO₄添加量、浸出时间和淋溶液pH对Pb浸出行为的影响规律试验研究。探讨了铅污染土固化体浸出机理。结果表明,KH₂PO₄对铅污染土有良好的稳定作用。酸溶液淋溶作用下固化体中Pb的释放行为与pH直接相关,强酸作用下Pb的溶出量大。固化体中Pb的浸出也与浸出液pH相关,强碱性有利于Pb的迁移。浸出液pH与固化体中的碱性水化产物释放量有关。对于pH=2和5溶液,Pb的累积浸出率随时间呈线性变化,而对于pH=3溶液,Pb的累积浸出率随时间呈两阶段线性变化。固化体在pH=2溶液浸泡下,Pb的释放机理为溶解控制;对于pH=3溶液浸泡,机理则为先溶解控制再表面冲刷;而对于pH=5溶液浸泡,Pb的释放机理为扩散控制。
- 铅污染土 /
- 固化/稳定化 /
- 酸雨 /
- 浸出机理
Abstract: KH₂PO₄—cement is used to soildify/stabilize the Pb contaminated soil. Leaching tests are conducted to study the leaching characteristics and mechanism of Pb in solidified bodies under acid rain soaking, and the effects of KH₂PO₄ addition, leaching time and leachate pH are took into account. The results show that KH₂PO₄ is effective to stabilize the Pb-contaminated soil. The Pb leaching is related to pH of leachant directly, and the leaching amount of Pb increases with acidity. What’s more, Pb leaching is also related to pH of leachate, and strong alkaline of leachate is conducive to the Pb mobility. For the acid solutions with pH of 2 and 5, the cumulative leaching ratio of Pb changes with time linearly, but the two-stage linear variation is founded for the acid solutions with pH of 3. pH of the leachate is in relation to the leaching amount of alkaline materials in S/S bodies. The controlling leaching mechanism of Pb changes with leachant pH, and it is presented that the leaching mechanism changes from dissolution to diffusion with the increasing leachant pH.
- Pb-contaminated soil /
- stabilization/solidification /
- acid rain /
- leaching

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参考文献(13)

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