Chemical speciation of metal elements in agricultural and non-agricultural soils

摘要

The chemical speciation of metal (Fe, Al, Mn and Cr) elements in agricultural and non-agricultural soils was investigated in upstream of the Pearl River, China. The result showed that Fe, Al and Cr in most of the samples, residual fractions accounted for more than 80% of their total concentrations. Mn in most of the samples, the reducible fractions were more than 40%, and generally more than residual fractions, oxidizable and weak acid soluble fractions. The mobility factors (MF) of Mn were the highest in both agricultural and non-agricultural soils, suggesting that the mobility of Mn were the strongest among the four metal elements. The MFs of Fe and Cr were almost zero, suggesting their mobility were low.