重金属污染土壤修复淋洗剂研究进展

Research advances of rinsing reagents favorable for remediating heavy metal soil-contaminants

综述了重金属污染土壤修复淋洗剂的分类和研究现状,比较了不同淋洗剂的淋洗效果和优缺点,综合分析各种淋洗剂在实际应用中遇到的问题,提出了今后淋洗技术的研究方向。

This paper aims to offer its research results on the soil pollution by heavy metals so as to reduce our biological environment, food safety research advances of rinsing reagents favorable for remediating heavy metal soil-contaminants in hoping to promote the sustainable development of our agriculture. As a matter of fact for the time being, soil washing remains the chief agricultural technique to remove the soil contaminants, which is characteristic of time-consuming and low productivity. This paper has made a retrospective overview of the recent advances in reagents for the remediation of the contaminated soil. The reagents widely used in soil rinsing can be categorized into three groups： inorganic rinsing, chelating agents and surfactants. Here we would like to analyze the advantages and disadvantages of the three reagents with details, based on the recent laboratory investigations and field applications of soil washing systems. Inorganic rinsing had a high effectiveness in the removal of heavy metals in the soil, but they have destructive effects on the structure of soils. Chelating agents were equally effective. The applications of traditional chelating agents were limited by their potential toxicity to the environment. The natural polymeric chelating agents were environmental friendly and had a bright perspective. The bio-surfactant,with biodegradability and no toxicity, was a better choice though its removal efficiency proves lower. We have also proposed the theoretical evidence for mixed leaching technology. Soil rinsing technology has been considered as an extensively-apphcable remediation for heavy mental contaminated soils, and the first large-scale project for soil rinsing technology has been successfully applied in America in 1992. And, later, corresponding research has just started at home, and more laboratory studies began to take on a certain scale, and thus comes the need for research promotion. However, the cost of the reagent remains the main concern in the field application. The costs might be reduced substantially if the remediation technology could be regenerated and recycled, If so, large-scale application can be fully expected to come about in the near future.