Effect of sulfate erosion on strength and leaching characteristic of stabilized heavy metal contaminated red clay  

硫酸盐侵蚀条件下固化重金属污染土强度及浸出特性（英文）

作　　者：Hai-qing ZHANG Yu-you YANG Yu-cheng YI 张海清;杨宇友;易宇成(中国地质大学(北京)工程技术学院,北京100083)

机构地区：[1]School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第3期666-675,共10页中国有色金属学报（英文版）

基　　金：Project(41472278) supported by the National Natural Science Foundation of China;Project(2015B071) supported by the Beijing Nova Program,China;Projects(53200859533,53200859536) supported by the Fundamental Research Funds for the Central Universities of China

摘　　要：Solidification/stabilization(S/S)technology has been widely used for remediation of the heavy metal contaminated soils.The heavy metal ions will be leached from the stabilized contaminated soil under sulfate erosion conditions,which gives rise tosecondary contamination to the areas around the mine sites.The commonly used Portland cement,fly ash and quicklime were takenas binder raw materials with various mix proportions.And then,the sulphuric acid and nitric acid method was used to investigate theleaching characteristic of stabilized heavy metal contaminated soils.The effects of binder types and binder contents,sulfateconcentrations(1.5,3.0and6.0g/L)and erosion time(0,7,14and28d)on leached concentrations of heavy metal ions fromcontaminated soils were studied.Moreover,a parameter named immobilization percentage(IP)was introduced to evaluate theinfluence of erosion time and sulfate concentration on immobilization effectiveness for heavy metal ions.The results showed that,theleached heavy metal concentrations increased with sulfate concentration and erosion time.Comparatively speaking,the compositebinders that had calcium oxide in it exhibited the worst solidification effectiveness and the lowest immobilization percentage,withthe largest leached heavy metal concentration.污染土修复常采用固化稳定化技术。固化稳定化重金属污染土在酸侵蚀条件下其重金属离子会重新溶出,从而导致对周边环境的二次污染。以常用的水泥、粉煤灰和石灰为固化剂原料,设计不同组合及配比的固化剂,通过无侧限抗压强度试验及硫酸/硝酸法毒性浸出试验研究固化重金属污染土在酸侵蚀条件下的强度及浸出特性。探讨固化剂类型、硫酸盐浓度(1.5,3.0,6.0 g/L)和侵蚀龄期(0,7,14,28 d)对固化重金属污染土的强度及溶出浓度的影响,并引入固定率参数,进一步量化考察侵蚀龄期和侵蚀浓度对重金属离子固定率的影响。结果表明:重金属离子的浸出量随着硫酸盐侵蚀浓度和侵蚀龄期的增加而增加;相对而言,含氧化钙的固化剂对重金属污染土的固化效果较差,重金属离子浸出量大,固化率低。

关 键 词：SOLIDIFICATION/STABILIZATION heavy metal contaminated soil sulfate erosion sulphuric acid and nitric acid method 

分 类 号：X53[环境科学与工程—环境工程]