College of Informatics, South China Agricultural University, Guangzhou, Guangdong, PR China.
J Hazard Mater. 2011 Dec 30;198:13-21. doi: 10.1016/j.jhazmat.2011.10.003. Epub 2011 Oct 6.
Mobility and bioavailability of soil heavy metals strongly depend on their fractions. Secondary-phase fraction (SPF) of heavy metal, including acid-soluble, reducible and oxidizable fractions, is considered as direct and potential hazardous fraction to organisms. The ratio of SPF to the total concentration of heavy metal represents its bioavailability. In this study, 126 topsoil samples were collected in Kunshan, Jiangsu, China. Fraction concentrations of heavy metals, and their bioavailability and spatial distributions were determined, and relationships between their fractions and types of industry zones were analyzed. Results showed that Cd and Pb had the greatest SPFs among all metals (78.61% and 62.60%, respectively). Great SPFs of Cd and Pb were observed in the dyeing and paper-making industry zone, while great SPFs of Cr, Cu, Zn, Ni were in the smelting and plating industry zone. For most metals, fraction distributions were controlled by soil organic matter and clay contents. Spatial principal component analysis showed SPFs of heavy metals can be explained by two principle components (PCs). PC1 represented SPFs of Cd, Cr, Cu, Pb and Zn, while PC2 represented SPFs of Ni and Co. The spatial distributions of SPFs were influenced by geochemical character, industrial sewage irrigation and soil physico-chemical properties.
土壤重金属的迁移性和生物可利用性强烈依赖于其赋存形态。重金属的次生相（SPF），包括酸可提取相、可还原相和可氧化相，被认为是对生物具有直接和潜在危害的相。SPF 与重金属总浓度的比值代表了其生物可利用性。本研究在中国江苏昆山采集了 126 个表层土壤样品。测定了重金属的赋存形态及其生物可利用性和空间分布，并分析了它们的赋存形态与工业类型区之间的关系。结果表明，Cd 和 Pb 的 SPF 最高（分别为 78.61%和 62.60%）。Cd 和 Pb 的 SPF 在印染造纸工业区最高，而 Cr、Cu、Zn、Ni 的 SPF 在冶炼电镀工业区最高。对于大多数金属来说，赋存形态受土壤有机质和粘土含量的控制。空间主成分分析表明，重金属的 SPF 可以用两个主成分（PCs）来解释。PC1 代表 Cd、Cr、Cu、Pb 和 Zn 的 SPF，而 PC2 代表 Ni 和 Co 的 SPF。SPF 的空间分布受地球化学特征、工业污水灌溉和土壤理化性质的影响。
