Understanding trace elements mobility in soils,extracting agents,and their relationships with soil components,are essential for predicting their movement in soil profile and availability to plants.A laboratory study w...Understanding trace elements mobility in soils,extracting agents,and their relationships with soil components,are essential for predicting their movement in soil profile and availability to plants.A laboratory study was conducted to evaluate extractability of cadmium(Cd),cobalt(Co),copper(Cu),nickel(Ni),and zinc(Zn)from calcareous soils utilizing various extracting agents to be specific CaCU,DTPA,EDTA,HNO3,MgCl2,NaN03,NH4NO3,and NH4OAc.Cluster analysis indicated that DTPA and NH4OAc,HN03 and EDTA,and M gCl2 and NH4NO3 extracting agents yielded comparative values,whereas NaN03 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements.The speciationof extracted trace elements in solutions indicated that in the CaCl2,NaN03,NH4NO3,and MgCl2 extracting agents most extracted Cd,Co,Ni,Zn,and part f Cu were as free ions and may be re-adsorbed on soils,leading to lower extractability,whereas,in the caseof HNO3 extracting agent,the likelihoodof re-adsorptionof trace elements may be little.The resultsof speciationof trace elements using NH4OAc DTPA,and EDTA extracting agents showed that Me-(Acetate)3,Me-(Acetate)2(aq),Me(DTPA)3-3-,Me(EDTA)2-.and MeH(EDTA)-complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils,leading to higher extractability.The resultsof this study are useful for short and long-term evaluationsof trace elements mobility and further environmental impacts.展开更多
文摘Understanding trace elements mobility in soils,extracting agents,and their relationships with soil components,are essential for predicting their movement in soil profile and availability to plants.A laboratory study was conducted to evaluate extractability of cadmium(Cd),cobalt(Co),copper(Cu),nickel(Ni),and zinc(Zn)from calcareous soils utilizing various extracting agents to be specific CaCU,DTPA,EDTA,HNO3,MgCl2,NaN03,NH4NO3,and NH4OAc.Cluster analysis indicated that DTPA and NH4OAc,HN03 and EDTA,and M gCl2 and NH4NO3 extracting agents yielded comparative values,whereas NaN03 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements.The speciationof extracted trace elements in solutions indicated that in the CaCl2,NaN03,NH4NO3,and MgCl2 extracting agents most extracted Cd,Co,Ni,Zn,and part f Cu were as free ions and may be re-adsorbed on soils,leading to lower extractability,whereas,in the caseof HNO3 extracting agent,the likelihoodof re-adsorptionof trace elements may be little.The resultsof speciationof trace elements using NH4OAc DTPA,and EDTA extracting agents showed that Me-(Acetate)3,Me-(Acetate)2(aq),Me(DTPA)3-3-,Me(EDTA)2-.and MeH(EDTA)-complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils,leading to higher extractability.The resultsof this study are useful for short and long-term evaluationsof trace elements mobility and further environmental impacts.
