Leaching of heavy metals from contaminated soils using EDTA
Leaching of heavy metals from contaminated soils using EDTA
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DOI：
10.1016/s0269-7491(00)00176-7
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发表时间：
2001-01-01
影响因子：
8.9
通讯作者：
McGrath, SP
中科院分区：
文献类型：
--
作者：
Sun, B;Zhao, FJ;McGrath, SP
采用间歇淋洗和柱淋洗试验研究了乙二胺四乙酸（EDTA）对4种污染土壤中Zn、Cd、Cu、Pb的萃取效果。在批实验中，提取的重金属几乎都是1：1的金属-EDTA络合物。提取液中Zn、Cd、Cu、Pb的含量与土壤中的含量相近，说明EDTA对这4种重金属的提取效果相近。相比之下，不同的洗脱模式得到的Zn，Cd，Cu和Pb的柱淋溶实验中使用0.01 MEDTA。Cu是最移动的或其中最移动的的四种重金属，其峰值浓度对应于在渗滤液中的全强度EDTA的到来。Zn和Cd的迁移率通常略低于Cu。Pb的移动的最少，在Cu和Zn的峰后，其洗脱量增加。淋洗和未淋洗土壤的连续分馏表明，重金属在各种操作定义的馏分有助于去除EDTA。在EDTA淋洗过程中，四种土壤中有两种发生了相当大的铁动员。EDTA浸出后的铁和锰的氧化物部分的重金属的减少发生在这两种土壤中，以及在第三种土壤，表现出很少的铁动员。结果表明，土壤中金属的不稳定性、金属解吸/溶解动力学和EDTA添加方式是控制EDTA浸出金属行为的主要因素。(C)2001爱思唯尔科技有限公司。保留所有权利。
Ethylenediaminetetraacetic acid (EDTA) extraction of Zn, Cd, Cu and Pb from four contaminated soils was studied using batch and column leaching experiments. In the batch experiment, the heavy metals extracted were virtually all as 1:1 metal-EDTA complexes. The ratios of Zn, Cd, Cu and Pb of the extracted were similar to those in the soils, suggesting that EDTA extracted the four heavy metals with similar efficiency. In contrast, different elution patterns were obtained for Zn, Cd, Cu and Pb in the column leaching experiment using 0.01 MEDTA. Cu was either the most mobile or among the most mobile of the four heavy metals, and its peak concentration corresponded with the arrival of full strength EDTA in the leachate. The mobility of Zn and Cd was usually slightly lower than that of Cu. Pb was the least mobile, and its elution increased after the peaks of Cu and Zn. Sequential fractionations of leached and un-leached soils showed that heavy metals in various operationally defined fractions contributed to the removal by EDTA. Considerable mobilisation of Fe occurred in two of the four soils during EDTA leaching. Decreases in the Fe and Mn oxide fraction of heavy metals after EDTA leaching occurred in both soils, as well as in a third soil that showed little Fe mobilisation. The results suggest that the lability of metals in soil, the kinetics of metal desorption/dissolution and the mode of EDTA addition were the main factors controlling the behaviour of metal leaching with EDTA. (C) 2001 Elsevier Science Ltd. All rights reserved.