土壤重金属原位钝化修复技术研究进展

随着现代工农业的发展,土壤重金属污染问题日趋严重,成为亟待解决的问题。重金属离子在土壤中可发生吸附、沉淀、络合、氧化还原等反应。土壤原位钝化修复技术是基于添加外源修复剂,与重金属发生系列反应,改变重金属在土壤中的赋存形态,以降低其在土壤中移动性和生物有效性的技术。目前研究较多的钝化剂主要有石灰类物质、富硅类物质、含磷物质、有机物料、黏土矿物、金属及金属氧化物、生物碳及纳米新型复合材料等。本文概述了以上钝化剂对重金属污染土壤的钝化修复效果和作用机理,对修复效果的化学和生物评价方法进行了归纳对比,并进一步从环境风险、评价体系、研究方法等方面分析了原位钝化修复技术存在的问题和今后的研究方向。提出钝化修复剂对土壤-作物系统的潜在环境风险、钝化材料修复效果的田间长期稳定性评价以及新型高效多功能材料的研制是该领域今后研究的重点。

A Review of In Situ Passivation Repairing Technology of Heavy Metals in Soil

With the rapid development of modern industry and agriculture, soil heavy metal pollution has become an important environmental problem, which needs to be solved urgently. Metal ions can be retained in the soil by sorption, precipitation, and complexation reactions. In situ stabilization technique was not to alter the total concentrations of heavy metals in soil, but to reduce the available fractions, mobility and bioavailability of heavy metals by addition of amendments with the reactions of dissolution/precipitation, exchange/adsorption, oxidation/reduction and organic complex. This method has been considered as a cost-effective and operation-easy measure, which is suitable for soil remediation at a large scale. Numerous amendments including inorganic materials such as liming materials, silicon rich materials, phosphate compounds, organic matter, metal oxides, clayey mineral, biochar, and other materials. This paper summarized the remediation effects and mechanisms of amendments on heavy metals polluted soils and chemical and biological evaluation methods of amending efficient. Last, the paper present the main problems and prospects of this technique on account of environmental risks, evaluation system, new products, and research methods. We proposed that future work should focus on the potential risks of immobilization amendments applied to the soil-crop system and its long-term effect on field and new products with high and multi efficiency.