化学钝化法修复重金属污染土壤研究进展

Research progress for chemical immobilization in heavy metal contaminated soils

化学钝化修复是通过往土壤中加入钝化剂,以调节和改变重金属在土壤中的物理化学性质,使其发生氧化还原、沉淀、吸附、螯合、抑制或拮抗等一系列反应,降低其在土壤环境中的生物有效性和可迁移性,从而减少这些重金属元素对动植物的毒性.这种方法因投入低、效率高、修复快速、操作简单等优点,对大面积污染土壤的修复具有较好的应用前景.文中系统地综述了土壤重金属污染现状、危害、来源、特点及化学钝化修复技术的类型、作用机理、影响因素、修复实例,并分析了化学钝化技术的研究现状、存在的问题及未来的发展方向.

The area of cultivated land contaminated by heavy metals such as Cd,Pb,As and Hg is nearly20million hm2in China,accounting for1/5of the total arable land.The overall situation of soil environment in China is worried.Remedying heavy metals-contaminated soil through effective ways is not only the requirement of promoting the economic development,but also the important guarantee for the protection of human health.Chemical immobilization relies on addition of the soil amendments to regulate and change the physical and chemical properties of heavy metals in soil,by redox process,precipitation,sorption,chelation,inhibition or antagonism,to decrease their bioavailability and mobility to reduce their toxicity to plants and animals.This method has a good application prospect for the remediation of large area contaminated soil due to the low investment,high efficiency,quick repair,simple operation and so on.This paper systematically reviews the current situation,hazards,sources,characteristics of heavy metals-contaminated soil,the types,mechanism,influence factors,restoration examples of chemical immobilization technology,and the current research status,existing problems and future development direction of this technology.