Sipos Péter, Németh Tibor, Kis Viktória Kovács, Mohai Ilona
Institute for Geochemical Research, Hungarian Academy of Sciences, H-1112 Budapest, Budaörsi út 45, Hungary.
Chemosphere. 2008 Sep;73(4):461-9. doi: 10.1016/j.chemosphere.2008.06.046. Epub 2008 Jul 31.
Soil mineral phases play a significant role in controlling heavy metal mobility in soils. The effective study of their relation needs the integrated use of several analytical methods. In this study, analytical electron microscopy analyses were combined with sequential chemical extractions on soils spiked with Cu, Zn and Pb. Our aims were to study the metal sorption capacity of soil mineral phases and the effect of presence of iron oxide and carbonate on this property of soil minerals. Copper and Pb were found to be characterized by higher and stronger sorption on the studied samples than Zn. Only the former two metals showed significant differences in their immobilized metal amounts on the studied samples and soil mineral particles. Highest metal amounts were sorbed on the swelling clay mineral particles (smectites and vermiculites), but iron-oxide phases may also have similar lead sorption capacity. Alkaline conditions due to the carbonate content of soils resulted both in increased sorption on the mineral particles for Cu and in enhanced role of precipitation for all the studied metals. On the other hand, the intimate association of phyllosilicates and iron resulted in significant increase in metal sorption capacity of the given particle. The results of sequential extractions could be successfully completed by the analytical electron microscopy analyses for studying the sorption capacity of discrete mineral particles. Their integrated use helps us in better understanding the heavy metal-mineral interactions in soils.
土壤矿物相在控制土壤中重金属的迁移性方面发挥着重要作用。对它们之间关系进行有效的研究需要综合运用多种分析方法。在本研究中，将分析电子显微镜分析与对添加了铜、锌和铅的土壤进行的连续化学萃取相结合。我们的目的是研究土壤矿物相的金属吸附能力以及氧化铁和碳酸盐的存在对土壤矿物这一特性的影响。研究发现，铜和铅在所研究的样品上表现出比锌更高且更强的吸附特性。只有前两种金属在所研究的样品和土壤矿物颗粒上的固定金属量存在显著差异。最高的金属量吸附在膨胀性粘土矿物颗粒（蒙脱石和蛭石）上，但氧化铁相也可能具有类似的铅吸附能力。由于土壤中的碳酸盐含量导致的碱性条件，既增加了铜在矿物颗粒上的吸附，也增强了所有研究金属的沉淀作用。另一方面，层状硅酸盐与铁的紧密结合导致给定颗粒的金属吸附能力显著增加。通过分析电子显微镜分析来研究离散矿物颗粒的吸附能力，连续萃取的结果能够成功完成。它们的综合运用有助于我们更好地理解土壤中的重金属 - 矿物相互作用。
