Recycling of EDTA solution after soil washing of Pb, Zn, Cd and As contaminated soil.
Recycling of EDTA solution after soil washing of Pb, Zn, Cd and As contaminated soil.
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DOI：
10.1016/j.chemosphere.2011.11.004
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发表时间：
2012-02
期刊：
影响因子：
8.8
通讯作者：
M. Pociecha;D. Lestan
中科院分区：
文献类型：
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作者：
M. Pociecha;D. Lestan
已知用EDTA洗涤土壤是从污染土壤中去除有毒金属的有效手段。然而，回收用过的土壤洗涤溶液的实用方法仍然是一个未解决的技术问题。在实验室规模的实验中，我们证明了使用酸沉淀从提取Pb（5330 mgkg −1）、Zn（3400 mgkg − 1）、Cd（35 mgkg −1）和As（279 mgkg −1）污染土壤后获得的用过的土壤洗涤液中回收高达50%的EDTA的可行性。高达100%的EDTA残留在洗涤液中和100%，97%，98%和100%的初始铅，锌，镉和砷浓度的溶液中，分别被删除在电解池中使用石墨阳极。我们采用回收的EDTA和处理后的洗涤液，以制备回收的土壤洗涤液，具有相同的潜力，从土壤中提取有毒金属的原始。土壤洗涤的效率取决于EDTA的浓度。使用两次回收的30 mmol EDTA kg-1土壤，我们从污染土壤中去除了44%，20%，53%和61%的Pb，Zn，Cd和As。
Soil washing with EDTA is known to be an effective means of removing toxic metals from contaminated soil. A practical way of recycling of used soil washing solution remains, however, an unsolved technical problem. We demonstrate here, in a laboratory scale experiment, the feasibility of using acid precipitation to recover up to 50% of EDTA from used soil washing solution obtained after extraction of Pb (5330mgkg−1), Zn (3400mgkg−1), Cd (35mgkg−1) and As (279mgkg−1) contaminated soil. Up to 100% of EDTA residual in the washing solution and 100%, 97%, 98% and 100% of initial Pb, Zn, Cd and As concentration in the solution, respectively, were removed in an electrolytic cell using a graphite anode. We employed the recovered EDTA and treated washing solution to prepare recycled soil washing solution with the same potential for extracting toxic metals from soil as the original. The efficiency of soil washing depends on the EDTA concentration. Using twice recycled 30mmol EDTA kg−1soil, we removed 44%, 20%, 53% and 61% of Pb, Zn, Cd and As, respectively, from contaminated soil.