摘要
【目的】研究重金属离子污染条件下黄土物理化学性质和土体工程性质的改变,为污染黄土的工程性质评估提供依据。【方法】以杨凌黄土为研究对象,在土中分别掺入Zn^(2+)、Cr^(3+)和Cu^(2+),对不同重金属污染黄土的颗粒组成、pH值、易溶盐总量、阳离子含量进行测定,并利用直剪试验和压缩试验测试其剪切及压缩特性的变化。【结果】随重金属离子掺量的增大,被污染黄土的黏粒含量明显减少,pH值降低,易溶盐总量及Ca^(2+)、Mg^(2+)、Na+、K+含量明显增加;杨凌黄土经重金属离子污染后黏聚力下降,内摩擦角增大,并且压缩模量随重金属离子掺量的增加而逐渐增大,压缩系数总体减小,土体的压缩性变小。【结论】随着重金属污染程度的加剧,在黄土中的碳酸盐水解、土颗粒表面离子交换吸附、阳离子含量增加的共同作用下,污染黄土物理化学及工程性质会发生较大变化。
【Objective】This study investigated the changes in physical-chemical and engineering properties of loess caused by heavy metal ions to provide information for engineering evaluation of contaminated loess.【Method】The polluted loess with different concentrations of Zn^2＋,Cr^3＋ and Cu^2＋ were artificially prepared with loess from Yangling.The basic properties of polluted loess were studied,including particle size,pH value,total soluble salt,contents of Ca^2＋,Mg^2＋,Na^＋,and K^＋,and compression and shear characteristics.【Result】The content of clay and pH value decreased with the increase of heavy metal ions.On the contrary,the contents of soluble salt and Ca^2＋,Mg^2＋,Na^＋,and K^＋ increased significantly.The cohesion force decreased,while the internal friction angle increased with the increase of heavy metal ions.The modulus of compression increased and the compressibility of soil decreased after contaminated by heavy metal ions.【Conclusion】The pollution of heavy metal ions had significant influence on physical-chemical and engineering properties of loess due to hydrolysis in calcites,exchange adsorption and increase of ions contents.
作者
刘刚
杨秀娟
樊恒辉
史祥
李普
LIU Gang Yang Xiujuan FAN Henghui SHI Xiang LI Pu(College of Water Resources and Architectural Engineering, Northwest A＆F University ,Yangling , Shannxi 712100, China)
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2017年第2期213-218,226,共7页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家自然科学基金青年项目(51409217)
中央高校基本科研业务专项科技创新一般项目(2014YB047)
陕西省社会发展攻关项目(2013k13-04-11)
榆林市产学研合作项目(2014cxy-05)
陕西省教育厅项目(16JK1897)
关键词
环境岩土工程
污染土
重金属离子
黄土
物理化学性质
工程性质
environmental geotechnical engineering
contaminated soil
heavy metal ions
loess
physical chemical properties
engineering properties
