污染土壤/底泥电动修复研究进展

Research Progress on Electro-kinetic Remediation of Contaminated Soil/Sediment

修复污染土壤/底泥对改善生态环境质量极为重要,通过对污染土壤/底泥施加电场,可使污染物定向迁移、富集并去除。综述了电动修复的发展历程,比较了重金属、有机污染物及复合污染物的电动修复机理及其限制因素,分析了土壤预处理(加入酸、氧化剂、共溶剂、表面活性剂,搅拌,升温等)、电极优化(交换电极、阳极逼近、电极矩阵等)、多技术(EK-PRB、Fenton、IEM、ASC、超声波、电解质增强等)联用对单一电动修复的性能优化概况。总体来看,污染物分离不彻底、土壤/底泥理化性质和微观结构改变、原位规模化应用困难等制约了电动修复污染土壤/底泥的效果。针对上述技术瓶颈,提出污染原位分离-污染物处理-有价资源回收的一体化电动修复技术。该技术可解决电动修复易破坏土壤生态和污染物难以外排的问题,实现了污染处理和有价资源的回收。

Remediation of contaminated soil/sediment is extremely important for improving eco-environmental health.By applying electric field to contaminated soil/sediment,pollutants can be migrated,enriched and removed.In this paper the history of electro-kinetic remediation research is reviewed,and the mechanisms of electro-kinetic remediating heavy metals,organic pollutants and compound pollutants are compared.The performances of soil pretreatment(adding acid,oxidant,co-solvent and surfactant,stirring,and heating),electrode optimization(exchange electrode,anode approximation,and electrode matrix),multi-technology combination(EK-PRB,Fenton,IEM,ASC,ultrasonic,electrolyte enhancement)in optimizing the single electro-kinetic remediation are also examined.In general,the incomplete separation of pollutants,the change in soil/sediment’s microstructure as well as physical-chemical properties,and the difficulty of large-scale in-situ application have restrained the engineering application of electro-kinetic in remediating contaminated soil/sediment.To tackle such technical challenges,an integrated electro-kinetic remediation technology involving in-situ pollutant separation,separated contaminant treatment,and valuable resource recovery is proposed.The proposed technology could solve the problem of damage to soil ecology and overcome the difficulty of pollutant drainage.