富集因子在环境地球化学重金属污染评价中的应用

Application of the Enrichment Factor in Evaluating of Heavy Metals Contamination in the Environmental Geochemistry

介绍了富集因子的概念、技术路线及应用方法,重点讨论了富集因子计算中的关键环节———如何选择参考元素及确定背景值;总结了参考元素应满足的3个条件,即稳定性、单一自然源、与其他污染元素显著相关;论述了背景值的重要意义以及确定方法,分析了全球元素质量分数平均值和区域背景值在富集因子应用中的不同效果;介绍了污染的判断标准。以湖北省某湖泊表层底泥为例说明了富集因子的计算过程,结果表明湖泊底层沉积物未受重金属污染,并通过地质积累指标对计算结果进行了检验。最后论述了富集因子存在的不足,指出其在区域性的、或特殊地质环境中的重金属污染评价中具有良好的应用前景。

Enrichment factor（F） is an effective method in evaluating heavy metals contamination degree and identifying the origin of heavy metals in the superficial environment. This paper expatiates the concept, principle and application of enrichment factor. It claims that the key in calculating F value is the reference element selection and the background value determination. The reference element must satisfy three conditions：stability,single natural origin and significant correlation with other metals. Meanwhile, it introduces the method and details of determining background value during calculating F value. It also discusses the difference between the global background and regional background. A lake bottom sediments in Hubei Province was employed to illuminate the process of calculating F value. It is concluded that the lake bottom sediments are not contaminated by heavy metals such as As,Cd, Hg,Cu,Pb,Zn,Cr, Ni, which was validated by calculating geoaccumulation index（Igeo） with the same data. Finally, the paper points out that enrichment factor（F） is promising in surveying heavy metals contamination in regional scale or special geological environment.