Heavy metal contaminants removal by soil washing
Heavy metal contaminants removal by soil washing
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DOI：
10.1016/s0304-3894(99)00149-1
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发表时间：
1999-12-23
影响因子：
13.6
通讯作者：
Smith, EH
中科院分区：
文献类型：
--
作者：
Abumaizar, RJ;Smith, EH
在实验室规模的批量和柱式实验中，评估了土壤洗涤对含镉、铬、铅和锌粉砂去污的可行性。采用乙二胺四乙酸二钠溶液（Na(2)EDTA）、焦亚硫酸钠溶液（Na2S2O5）（一种廉价的还原试剂）和含有这两种试剂的混合物的溶液对土壤样品进行螯合剂萃取。用去离子水（DI水）批量和柱洗污染土壤表明，样品中约70%的镉是弱结合的，在中性pH的水溶液中很容易动员，其次是约25%-30%的锌，约20%-25%的铬，只有约10%的铅。在所测试的洗涤试剂中，Na(2)EDTA溶液通常比Na2S2O5更有效地去除土壤样品中的重金属。Na、EDTA对铅的去除效果优于锌和镉，对铬的去除效果不明显。加入0.1 M Na2S2O5后，0.01 M Na(2)EDTA溶液对镉，尤其是锌的去除效果显著增强，这表明这两种试剂的混合物可能是某些污染土壤的经济最佳解决方案。(C) 1999 Elsevier Science B.V.版权所有
The feasibility of soil washing for decontaminating a silty sand spiked with cadmium, chromium, lead, and zinc was evaluated in laboratory-scale batch and column experiments. Soil samples were subjected to chelant extraction using a solution of disodium salt of ethylenediaminetetraacetic acid (Na(2)EDTA), sodium metabisulfite (Na2S2O5) solution (an inexpensive reducing reagent), and a solution containing a mixture of the two reagents. Batch and column washing of the contaminated soil with deionized water (DI water) revealed that approximate to 70% of the cadmium in the sample is weakly bound and:readily mobilized in aqueous solution at neutral pH, followed by approximate to 25%-30% of zinc, approximate to 20%-25% chromium, and only approximate to 10% of lead. Of the washing reagents tested, Na(2)EDTA solutions were generally more effective than Na2S2O5 for removing heavy metals from the soil samples. Na,EDTA preferentially extracted lead over zinc and cadmium but exhibited little impact on chromium removal. Cadmium and, especially zinc, removal by a 0.01-M Na(2)EDTA solution were enhanced considerably by inclusion of 0.1 M Na2S2O5, suggesting that a mixture of the two reagents may provide an economically optimum solution for certain contaminated soils. (C) 1999 Elsevier Science B.V. All rights reserved.