土壤重金属有效态含量检测与监测现状、问题及展望

随着经济和社会的发展,土壤重金属污染对粮食安全及人类的身体健康构成了巨大的威胁,而目前广泛采用的全量检测法并不能准确地反映土壤重金属的生物毒性。为了更好地了解土壤重金属的污染情况及其生物毒性,需快速有效检测土壤重金属的赋存形态及有效态含量。本文介绍了土壤有效态重金属的定义及其在土壤-有机体系统中的转移;并结合国内外相关研究领域的文献资料,按检测对象将土壤重金属有效态的检测方法分为直接检测方法(化学检测方法和物理检测方法)和间接检测方法(生物指示法),系统阐述了化学检测方法中的浸提法,物理检测方法中的梯度扩散薄膜技术和光谱分析法,及生物指示法中的指示植物检测法、微生物检测法和动物检测法的研究进展、适用范围及优缺点,概括了目前检测方法存在的主要问题是不能同时满足大面积监测和精确检测两个方面。并指出快速、大面积、原位测定污染物种类和含量,采取相应措施保障粮食安全及人类身体健康是目前迫切需要解决的问题。本文将土壤-植物-人作为一个整体,了解重金属有效态在该系统中的迁移富集机理,认为在此基础上选择合适的数据处理方法及建模参数,结合遥感、地理信息系统和全球定位系统对土壤重金属污染进行原位立体监测,是未来土壤重金属有效态含量检测与监测研究的主要发展方向。

The detection and monitoring of available heavy metal content in soil: A review

With the rapid development of economy and society, the problem of heavy metal contamination in soil is becoming serious increasingly, which threatens the food security and human health. However, the detection method of total concentration of heavy metal in soil can not accurately reflect the actual toxicological bioavailability of heavy metal in soil. To further analyze the existing forms of heavy metal in soil and their biotoxicity, it is necessary to assess both the existing forms and the contents of heavy metal. This article described the definition of availability of heavy metal and its transfer mechanism in soil-organism system. According to related data and documents, divided the detection methods of availability of heavy metal in soil into two kinds of methods:direct methods (chemical detection methods and physical detection methods) and indirect methods (biological indicator methods). The research progress, application scope and characteristics of chemical extraction methods, diffusive gradients in thin-films (DGT), spectrum analysis methods, plant indicator method, microbial indicator method and soil animal indicator method were systematically set forth, and the major problems of existing detection methods were summarized. At last, the paper pointed out that it was urgent to ensure food security and human health by preventing soil pollution and remediation of contaminated soil based on rapid, in-situ and non-invasive detection and monitoring of forms, contents and pollution degrees of heavy metals in soil in large-area. However, it depends on developing of more accurate detection methods by understanding the mechanism of the translocation and accumulation of heavy metal in system of soil-crop-human. In addition, the in-situ stereo detection and monitoring methods combined with remote sensing (RS), geographic information system (GIS) and global positioning system (GPS) are the hot spots of the detection and monitoring of heavy metal speciation in soil in future, and with the development of hyperspectral remote sensing technology and data processing technology, this kind of detection and monitoring methods of heavy metals can meet the requirements of large area and accurate detection and monitoring of available heavy metals contents in soil.