摘要
使用自行设计电动修复装置,针对镉污染黏性土开展了室内土柱试验,分析了土柱中镉的去除效果、修复前后污染土的微观结构变化和镉的形态特征,探究了土壤中镉的去除机制。结果表明:镉初始浓度较小时,增大电压可以显著提高镉的去除率,电压的增大可加快土中不稳定形态镉的迁移。当镉初始浓度较大时,残余在土柱中的镉含量呈现出从阳极侧到阴极侧逐渐增大的现象。经过电动修复后,土颗粒从球形呈现的黏聚体结构变为了光滑、松散的结构。电压为40V时,约95%的弱酸提取态及可还原态镉从土壤中去除,修复后土柱中的残渣态等稳定形态的镉约为总镉的60%,有效降低了镉污染土的毒性。
A self-designed electrokinetic remediation device is used to carry out the soil column tests on cadmium-contaminated clayey soil.The removal mechanism of cadmium in soil is explored by analyzing the removal effects of cadmium in a soil column,the microstructural change of contaminated soil before and after remediation and the species analysis of cadmium.The results show that when the initial concentration of cadmium is relatively small,the removal rate of cadmium increases remarkably when increasing the voltage,since the unstable cadmium migrates faster at greater voltage.When the initial concentration of cadmium is relatively great,the residual content of cadmium exhibits a gradual increase trend from the anode to cathode.After the electrokinetic remediation,the appearance of soil particles changes from a spherical cohesive structure to a smooth and loose one.When the voltage is 40 V,about 95%of the weak acid extractable and reducible cadmium is removed from the soil,and the residual cadmium in the soil column after remediation is about 60%of the total cadmium,which effectively reduces the toxicity of the cadmium-contaminated soil.
作者
王艳
史鑫锋
薛逸翔
郑佳挺
陈冠年
WANG Yan;SHI Xinfeng;XUE Yixiang;ZHENG Jiating;CHEN Guannian(Department of Civil Engineering,Ningbo University,Ningbo 315211,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2023年第S01期16-19,共4页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(42107174,51678311)
关键词
电动修复
镉
污染黏性土
electrokinetic remediation
cadmium
contaminated clayey soil
