过一硫酸盐-高铁酸盐-FeS体系土柱淋洗修复邻二氯苯污染土壤

Peroxymonosulfate-ferrate-FeS system soil column leaching to remediate o-dichlorobenzene contaminated soil

有机氯污染土壤的修复是目前土壤修复的一个重点和难点。针对有机氯难降解的问题,本文采用土柱淋洗模拟异位淋洗修复的方式,利用过一硫酸盐-高铁酸盐-FeS(PFI)氧化体系对邻二氯苯污染土壤进行了修复。采用土柱实验测试了过一硫酸盐和高铁酸钾的复合溶液在土壤中的渗透系数(1.46×10^(-4)~2.46×10^(-4)cm/s),实验发现随氧化物浓度增大,渗透系数变小。使用PFI对污染土壤进行了土柱淋洗修复实验,结果表明,PFI可实现对深层土壤的氧化修复,在适中浓度下经过3.8h淋洗,可将深度为5cm、15cm、25cm处的土壤中的邻二氯苯最终残留率降低为17.5%、20.0%和30.3%。在改变土壤性质方面,土柱实验表明,PFI对土壤性质的改变与土壤深度呈负相关,即土壤越浅,改变得越彻底。综上所述,PFI氧化体系对含氯苯有机污染场地修复有良好的应用前景。

The remediation of organic chlorine contaminated soil is currently a significant and sticking point in soil remediation.For the trouble of hard degradation in organochlorine,soil column leaching was used to simulate in-situ remediation and peroxymonosulfate-ferrate-FeS(PFI)oxidation system was used to remediate o-dichlorobenzene contaminated soil.The soil column experiment was used to test the permeability coefficient(1.46×10^(-4)~2.46×10^(-4)cm/s)of the compound peroxymonosulfate and potassium ferrate solution in the soil.It was found through experiments that as the oxide concentration increased,the permeability coefficient became smaller.The PFI was used in soil column leaching remediation experiments on contaminated soil.It showed that the oxidation and remediation of deep soil could be achieved by PFI.The final residual ratio of o-dichlorobenzene in the soil at 5cm,15cm and 25cm depth were reduced to 17.5%,20.0%and 30.3%respectively by leaching at a middle concentration for 3.8h.In terms of changing soil properties,soil column experiments showed that the change of soil properties by PFI had a negative correlation with soil depth.The shallower the soil,the more thoroughly the soil properties changed.In summary,the PFI oxidation system has good prospects for the remediation of chlorobenzene-containing organic contaminated sites.