石灰对土壤重金属污染修复的研究进展

Remediation of Heavy Metal Contaminated Soils by Lime: A Review

随着中国经济的快速发展,工农业导致包括重金属在内的大量污染物被排放到环境中,土壤环境污染日趋严峻。石灰由于其在土壤重金属污染修复方面具有成本低廉、操作简单、修复快速、效果明显等优势而受到越来越多的研究者关注,探讨石灰对土壤重金属污染修复效果及机理已成为当前研究的热点之一。笔者系统地综述了国内外近些年来有关石灰对重金属污染土壤修复的研究进展,并重点阐述石灰对土壤重金属生物有效性的影响机理,以及石灰对重金属污染土壤的修复效果。研究表明:石灰对重金属土壤的修复机理主要是通过改变土壤pH值、土壤阳离子交换量CEC、土壤盐基饱和度BS、土壤氧化还原电位Eh等过程影响重金属在土壤中的吸附、沉淀、络合等。同时,石灰施用量、土壤pH值、重金属污染程度、不同重金属种类以及土地利用类型等因素影响石灰的修复效果。因此,在实际修复过程中,为防止土壤出现板结现象,施用石灰过程中应考虑当地土壤的类型、石灰施用量、施用时期和施用方式等问题。研究为实现重金属污染耕地达标生产及阻控提供科学依据。

With the rapid economic development in China, industry and agriculture cause a lot of pollutants,including heavy metals, to be discharged into the environment, and the soil environmental pollution isbecoming more and more serious. Since lime repairing has low cost, simple operation, quick repairing processand obvious effect, it has attracted lots of attention, and the effect of lime on soil heavy metal pollution repairmechanism has become one of the hot research spots. In this paper, the research progress of the remediation ofheavy metal contaminated soils by lime was reviewed systematically. The influence mechanism of lime on thebioavailability of heavy metals in soils and the repairing effect of lime on soils contaminated by heavy metalswere discussed. The results showed that the mechanism of lime restoring heavy metal polluted soil was mainlythrough the adsorption, precipitation and complexation of heavy metals in soil by changing the soil pH value,CEC, BS and Eh. At the same time, types of heavy metal and land use could affect the repairing effect of lime.Therefore, in the actual repairing process, we should take into consideration the type of local soil, limeapplication rate, application period, and application methods, etc.