Synergistic Effects of Multiple Metal Contaminants on Electrokinetic Remediation of Soils
Synergistic Effects of Multiple Metal Contaminants on Electrokinetic Remediation of Soils
复制标题
多种金属污染物对土壤动电修复的协同效应
DOI：
10.1002/rem.1006
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
A. Al
中科院分区：
文献类型：
--
作者：
K. Reddy;S. Chinthamreddy;A. Al
本文提出了一个实验室规模的研究进行调查时，他们存在于土壤中的重金属单独和组合的去除。动电实验进行了两种类型的粘性土壤，高岭土和冰碛。这些土壤被污染的Cr（VI），与Ni（II），仅与Cr（VI），Ni（II）和Cd（II）的组合。结果发现，在高岭土，一个显着的pH值发生变化，由于电位的应用，影响吸附-解吸和溶解-沉淀，以及迁移的污染物的程度。然而，在冰碛中，pH值的变化没有受到显着影响。在高岭土和冰碛，迁移的Cr（VI）和Ni（II）是较高的，当它们单独存在时，他们与Cd（II）一起存在。Cr（VI）迁移作为单一或组合污染物是较低的高岭土相比，在冰碛。这一结果是由于在高岭土中阳极区域附近产生的低pH条件导致高Cr（VI）吸附到粘土表面。然而，在冰碛中，由于土壤中的高pH值条件，镍在存在或不存在共污染物的情况下沉淀。总的来说，本研究表明，吸附，沉淀，还原是重金属去除电动修复的显着阻碍机制。污染物迁移的方向和总体去除效率取决于污染物的极性、共污染物的存在以及土壤的类型。© 2001 John Wiley & Sons.
This article presents a bench-scale study performed to investigate the removal of heavy metals when they exist individually and in combination in soils. Electrokinetic experiments were conducted using two types of clayey soils, kaolin and glacial till. These soils were contaminated with Cr(VI) only, with Ni(II) only, and with Cr(VI), Ni(II), and Cd(II) combined. It was found that in kaolin, a significant pH variation occurred due to electric potential application, affecting the adsorption-desorption and dissolution-precipitation, as well as the extent of migration of the contaminants. In glacial till, however, pH changes were not affected significantly. In both kaolin and glacial till, the migration of Cr(VI) and Ni(II) was higher when they were present individually compared to when they existed together with Cd(II). Cr(VI) migration as single or combined contaminant was lower in kaolin as compared to that in glacial till. This result was due to the low pH conditions created near the anode region in kaolin that led to high Cr(VI) adsorption to the clay surfaces. In glacial till, however, nickel precipitated with or without the presence of co-contaminants due to high pH conditions in the soil. Overall, this study demonstrates that adsorption, precipitation, and reduction are the significant hindering mechanisms for the removal of heavy metals using electrokinetic remediation. The direction of the contaminant migration and overall removal efficiency depend on the polarity of the contaminant, the presence of co-contaminants, and the type of soil. © 2001 John Wiley & Sons.