Removal and redistribution of metals from contaminated soils by a sequential extraction method

The fate of heavy metals in a contaminated soil is dependent on both the total amount of metals and the chemical forms in which they exist. A widely applied sequential extraction method was used to study the metal speciation in soils. Sequential extraction for metal-contaminated individual soil components and synthetic soils was performed. The experimental results show that the specific reagents were effective for the extraction of metals from the corresponding individual soil components; but the impact of non-corresponding reagents on other soil components was also significant. The chemical forms in which metals exist in the synthetic soils were complicated and different. Metals in soils might be released and redistributed during the sequential extraction process, but knowledge about this behavior and the extent of metal redistribution is ambiguous.