Morphologic analysis and environmental risk assessment of heavy metal elements in sized-fractionational soils

Activity and environmental risk assessments of heavy metals in soil fractions were helpful to understand and control the behaviors,chemical transformation and rules of heavy metal in environment.Chemical analysis of Cu,Cd and organic carbon in each solid fraction of soils samples from three areas showed that the concentration of these components increased as particle size decreased,and the concentration of Cu or Cd was positively co-related with organic carbon,indicating colloids and nano-colloidal particles played an important role in retaining heavy metals.Chemical fractionation by morphologic method showed that Cd mainly existed in high active form,indicating a higher risk in soil environment while Cu mainly in lower active and inert forms,minor in higher environmental activity,indicating a lower environmental risk.The existed form of Cu in soils was probably related with the quality of the soils.