论文总字数：28306字

摘 要

离子污染物在粘土层中的运移问题一直是国际环境岩土工程界研究的重点议题之一，进行污染黏土层压缩变形引起的离子污染物逸出特性及覆盖控制的研究，对于垃圾填埋场、河底污染淤泥的原位处理和造成污染后的措施应对方面有较大的意义和较好的前景。

本文以三种不同覆盖层覆盖下的锌离子污染高岭土构成的复合土样（砂土覆盖下的污染高岭土复合土体、未污染高岭土覆盖下的污染高岭土复合土体和未污染膨润土覆盖下的污染高岭土复合土体）为研究对象，通过加压固结下污染物运移试验和无上覆荷载条件下的污染物扩散试验结合理论分析，对不同覆盖层情况下不同压缩固结条件下的锌离子运移特性进行研究。取得以下一些成果：

（1）通过加压固结下污染物运移试验对比比较了三种复合土体分别构成的五组试验样本的压缩性质，验证了相同加载状况下膨润土覆盖的复合土体最易压缩，高岭土覆盖的复合土体次之，砂土覆盖的经过初期砂土密实后最难压缩。

（2）通过加压固结下污染物运移试验和无上覆荷载条件下的污染物扩散试验对比比较了三种复合土体分别构成的五组试验样本中重金属离子污染物（锌离子）在不同覆盖层和压缩情况下的溢出浓度变化趋势。发现砂土覆盖下锌离子溢出浓度最高而膨润土覆盖下锌离子溢出浓度最低，在加载状况和不加载状况下对比发现，加压固结导致污染物运移的情况在沙土覆盖下更加明显。而在膨润土覆盖下虽然加压固结也造成锌离子溢出浓度增高，但是溢出浓度相对于无压情况下的扩散依然较低。

关键词：土壤固结；覆盖层；污染物；运移现象；对流；扩散；吸附；多孔介质。

A STUDY ON THE ESCAPE CHARACTERISTIC OF CONTAMINANTS CAUSED BY COMPRESSIVE DEFORMATION OF CONTAMINANTED CLAY AND THE CHOICE OF COVER

Abstract

The migration of ionic contaminants in the clay layer has been one of the key issues in the research of the international environmental geotechnical engineering, contaminated clay layer compression deformation caused by ionic contaminants escape characteristic and coverage control. For landfill and bottom silt pollution in situ processing and pollution measures with good prospect and great significance.

In this paper, three constitutes a different cover layer under the coverage of the zinc ion pollution kaolin composite soil sample (sand covered under polluted kaolin composite soil, uncovered polluted Kaolin Polluted kaolin composite soil and non pollution under the cover of the bentonite pollution kaolin composite soil) as the object of study, Based on the theoretical analysis of large diameter consolidation test and free diffusion test, the characteristics of zinc ion transport under different compression and consolidation conditions were studied. And achieve some of the following results:

(1) Through the pressure consolidation contaminant transport experiments compared the three kinds of composite soil formed five groups of test sample compression properties to verify the bentonite under the same loading condition coverage of composite soil is most likely to be compressed, kaolin coverage of composite soil times, sand covered after the initial dense sand most difficult compression.

(2) Through the pressure consolidation pollutants migration test and supreme cover load under the condition of pollutant diffusion contrast experiment compared three kinds of composite soil respectively, constitute the five groups of test sample contamination of heavy metal ions (Zn2 ) in different overburden and compression the overflow concentration change trend. Find sand cover overflow zinc ion concentration is the highest, and the bentonite covered overflow zinc ion concentration lowest under loading and unloading condition comparison, compression consolidation leads to contaminant transport in sandy soil under the cover of the more obvious. In the bentonite covered under the pressure of consolidation also caused the increase in the concentration of zinc ions, but the spillover concentration is still relatively low compared to the pressure of the pressure.

KEY WORDS: Soil consolidation; Cover; Pollutants; Transport phenomena; Advection; Dispersion; Sorption; Porous media.

目 录

摘 要 I

Abstract II

图汇总 a

表汇总 b

第一章 绪 论 1

1.1 引言 1

1.2 研究现状 1

1.3 存在问题及本文主要研究内容 2

1.3.1 存在的问题 2

1.3.2 本文研究主要内容 2

第二章 试验设备及试验方法 3

2.1 材料 3

2.2 试验内容及方法 3

2.2.1 试样制备 3

2.2.2 仪器和试样装填 4

2.2.3 加压固结下污染物运移试验 5

2.2.4 无上覆荷载条件下的污染物扩散试验 5

2.2.5 电导率与锌离子浓度之间的关系验证试验 6

第三章 试验结果 8

3.1 处于不同覆盖层下Zn² 污染高岭土的压缩固结情况 8

3.2 膨润土覆盖下Zn² 污染高岭土加载和不加载试验的固结情况分析 10

3.3 各试验组样本溶液电导率与锌离子浓度测试结果 11

3.4 膨润土覆盖的污染高岭土不同压缩情况下Zn² 溢出浓度分析 14

3.5 砂土覆盖的污染高岭土不同压缩情况下Zn² 溢出浓度分析 16

3.6 高岭土覆盖的污染高岭土压缩固结与Zn² 溢出浓度关系 18

3.7 压缩固结情况下不同覆盖层的污染高岭土中Zn² 溢出浓度分析 19

3.8 不加载情况下不同覆盖层的污染高岭土的Zn² 溢出浓度分析 20

3.9 长周期（14天）下膨润土覆盖的污染高岭土的观测数据 21

第四章 结论 24

4.1 结论 24

第五章 不足与展望 25

5.1 不足之处 25

5.2 展望 25

本文中使用的符号及其意义： 26

参考文献 27

致谢 28

图汇总

图2.1 实验室所用电导率仪 3

图2.3 大直径固结仪1 5

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