College of Resource and Environment, Hunan Agricultural University, Changsha, China.
Environ Monit Assess. 2010 Sep;168(1-4):215-22. doi: 10.1007/s10661-009-1105-4. Epub 2009 Aug 8.
This study was conducted to investigate the pollution load index, fraction distributions, and mobility of Pb, Cd, Cu, and Zn in garden and paddy soils collected from a Pb/Zn mine in Chenzhou City, China. The samples were analyzed using Leleyter and Probst's sequential extraction procedures. Total metal concentrations including Pb, Cd, Cu, and Zn exceeded the maximum permissible limits for soils set by the Ministry of Environmental Protection of China, and the order of the pollution index was Cd > Zn > Pb > Cu, indicating that the soils from both sites seriously suffered from heavy metal pollution, especially Cd. The sums of metal fractions were in agreement with the total contents of heavy metals. However, there were significant differences in fraction distributions of heavy metals in garden and paddy soils. The residual fractions of heavy metals were the predominant form with 43.0% for Pb, 32.3% for Cd, 33.5% for Cu, and 44.2% for Zn in garden soil, while 51.6% for Pb, 40.4% for Cd, 40.3% for Cu, and 40.9% for Zn in paddy soil. Furthermore, the proportions of water-soluble and exchangeable fractions extracted by the selected analytical methods were the lowest among all fractions. On the basis of the speciation of heavy metals, the mobility factor values of heavy metals have the following order: Cd (25.2-19.8%) > Cu (22.6-6.3%) > Zn (9.6-6.0%) > Pb (6.7-2.5%) in both contaminated soils.
本研究旨在调查中国郴州市某铅锌矿区采集的菜园土和稻田土中 Pb、Cd、Cu 和 Zn 的污染负荷指数、赋存形态和迁移性。采用 Leleyter 和 Probst 的连续提取程序对样品进行分析。总金属浓度（包括 Pb、Cd、Cu 和 Zn）超过了中国环境保护部规定的土壤最大允许限量，污染指数顺序为 Cd＞Zn＞Pb＞Cu，表明两个采样点的土壤均受到严重的重金属污染，尤其是 Cd。金属形态的总和与重金属总量相符。然而，菜园土和稻田土中重金属的形态分布存在显著差异。重金属的残渣态为主要赋存形态，菜园土中 Pb、Cd、Cu 和 Zn 的比例分别为 43.0%、32.3%、33.5%和 44.2%，而稻田土中 Pb、Cd、Cu 和 Zn 的比例分别为 51.6%、40.4%、40.3%和 40.9%。此外，所选分析方法提取的重金属水溶态和交换态比例在所有形态中最低。基于重金属的赋存形态，重金属的迁移因子值在两种污染土壤中的顺序为：Cd（25.2-19.8%）＞Cu（22.6-6.3%）＞Zn（9.6-6.0%）＞Pb（6.7-2.5%）。
