根际有机酸对土壤中重金属化学行为和生物有效性的影响研究进展

Research progress on the effects of rhizosphere organic acids on the chemical behavior and bioavailability of heavy metals in soil

介绍土壤中有机酸的种类、来源及其对土壤中重金属的化学行为和生物有效性的影响,归纳有机酸分泌差异化的影响因素及其改变土壤pH值的作用机理;重点阐述根际有机酸对土壤中重金属的赋存形态和生物有效性的影响机制;分析根际有机酸不仅可以通过酸化、络合和交换等非生物作用发挥活化营养物质和金属解毒的作用,还可以通过作为电子供体和充当电子传递体等生物作用改变土壤中重金属的形态或价态,进而影响土壤中重金属的迁移与转化。通过阐明有机酸的基本属性及其对土壤中重金属化学行为和生物有效性的影响机制,期待为有机酸更广泛的科学利用及其对土壤重金属污染的治理提供理论依据。

This article presented a review of the types and sources of organic acids in soil and their effects on the chemical behavior and bioavailability of heavy metals in soil.On the one hand,the factors affecting the differentiation of organic acid secretion and the mechanism of changing soil pH were summarized;on the other hand,it focused on the influence mechanism of rhizosphere organic acids on the occurrence and bioavailability of heavy metals in the soil.Rhizospheres organic acids can not only activate nutrients and detoxify metals through abiotic effects such as acidification,complexation and exchange,but also change the form or valence of heavy metals in the soil through biological effects such as being an electron donor and acting as an electron transfer body,thereby affecting the migration and transformation of heavy metals in the soil.By clarifying the basic properties of organic acids and their influence mechanisms on the chemical behavior and bioavailability of heavy metals in the soil,it was expected to provide a theoretical basis for the wider scientific use of organic acids and the treatment of soil heavy metal pollution.