Fractions of Cd,Zn and Their Correlation with Soil Black Carbon in Contaminated Soils Affected by a Smelting Furnace

摘要

Investigation and analysis of soils in the heavily polluted farm field nearby a smelting furnace showed that heavy metal concentrations and organic carbon content in the soil decreased with increasing distance from the smelting furnace. Zinc (Zn) and cadmium (Ca) concentrations in surface soil decreased from 27107 mg·kg-1 to 892 mg·kg-1 and from 18.7 mg·kg-1 to 1.04 mg·kg-1, respectively. It was found that soil organic carbon and black carbon had significantly positive relationship with the concentrations of total Zn and Cd in surface soils. BCR sequential extraction procedure was used to determine the concentration of Zn and Cd speciation forms in the contaminated soil. It was shown that Cd and Zn were predominant in exchangeable and reducible fractions. Heavy metal concentrations in soil size fractions tended to increase as particle size decreased.