PDF《（芋）污染土壤》

摘要: 铬渣污染土壤中三价铬[Cr (芋) ]比例较高, 为解决常规电动修复方法对 Cr 污染土壤中 Cr (芋) 去除效率低的问题, 提出了 高锰酸钾氧化-电动强化修复技术.

以配制的 Cr (芋) 污染高岭土和国内某铬渣污染场地土壤为研究对象, 施加

1 V ・ cm-1 直流电压, 采用阴极添加 KMnO4 溶液的形式氧化 Cr (芋) , 试验运行

96 h. 试验结果表明: 通过高锰酸钾氧化, 高岭土配土组的总铬去除效率从 对照组的 32.4%提高到 78.4%, 铬渣污染土壤组从对照组的 20.9%提高到 42.6%, 添加 KMnO4 溶液浓度增加, 去除效率提高. 在电场 作用下, 阴极加入的高锰酸钾以阴离子形式在土壤中向阳极迁移, Cr (芋) 以阳离子形式向阴极迁移, 部分 Cr (芋) 形成沉淀吸附在土壤 中. 高锰酸钾迁移过程中把部分 Cr (芋) 氧化为六价铬[Cr (遇) ], Cr (遇) 以含氧阴离子的形式向阳极迁移, Cr (遇) 迁移性好于 Cr (芋) , 有 效控制了 Cr (芋) 形成沉淀, 从而促进 Cr 的去除.研究表明, 高锰酸钾氧化-电动强化修复技术能显著提高铬的去除效率. 关键词: 高锰酸钾;

氧化;

电动修复;

三价铬;

土壤 中图分类号: X53 文献标志码: A 文章编号: 1672-2043 (2018) 06-1125-07 doi:10.11654/jaes.2017-1434 Potassium permanganate oxidation-electrokinetic advanced remediation for soils contaminated with trivalent chromium MENG Fan-sheng1 , NIE Lan-yu2 , XUE Hao1 , ZHANG Dao-ping1 (1.Chinese Research Academy of Environmental Sciences, Beijing 100012, China;

2.Rizhao Municipal Environmental Protection Bureau, Rizhao 276826, China) Abstract: The proportion of trivalent chromium[Cr (芋) ] is higher in soils contaminated with chromium residues. The potassium perman原ganate (KMnO4 )oxidation - electrokinetic advanced remediation method was proposed as a means to overcome the low Cr (芋)removal effi原ciency of the conventional electrokinetic method for the remediation of chromium-contaminated soil. A voltage of

1 V・ cm-1 DC was applied together with the addition of KMnO4 into the cathode for the advanced remediation of simulated Cr (芋) -contaminated Kaolin as well as chromium residue-contaminated soils collected from a chemical factory in China. Experiments were run for

96 hours. The total chromium [Cr (T) ] removal efficiency was significantly enhanced by the (KMnO4)oxidation-electrokinetic advanced remediation method, and the Cr (T)removal rate of the groups with KMnO4 oxidation was up to 78.4% and 42.6%, as compared with 32.4% and 20.9% for the control groups without KMnO4 oxidation, for the simulated Cr (芋) -contaminated Kaolin (32.4%)and chromium residue-contaminated soils, re原spectively. The Cr (T)removal rate enhancement increased with the increasing KMnO4 concentration. Under the direct electric field, the MnO-

4 added in the cathode moved toward the anode, and the Cr (芋)positive ions migrated toward the cathode through the soils;

some Cr (芋) ions were adsorbed on the soils by precipitation during migration. The other Cr (芋)ions were oxidized to hexavalent chromium[Cr (遇) ] ions during KMnO4 migration, and the Cr (遇)negative ion migrated toward to the anode. Because the migration rate of Cr (遇)ions was higher than that of Cr (芋)ions in the soils, the precipitation of Cr (芋)ions could be controlled effectively, and the chromium removal effi原ciency could be improved. Keywords: potassium permanganate (KMnO4 ) ;

oxidation;

electrokinetic remediation;

trivalent chromium;