Distribution and mobility of metals in agricultural soils near a copper smelter in South China.
The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH(2)OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl(2) extractable fraction. A large proportion of Cu was bound to the acidic H(2)O(2) extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier's procedure, and the order of mobility was Zn > Cd > Cu > Pb.
Hu
Ningjing
N
Soil and Environment Bioremediation Research Center, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China. hningjing@163.com
Li
Zeqin
Z
Huang
Peng
P
Tao
Cheng
C
D002104:Cadmium / Q000032:analysis; D002681:China; D002947:Cities; D003300:Copper; D003710:Demography; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007854:Lead / Q000032:analysis; D015636:Magnesium Chloride / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis*; D009532:Nickel / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*; D015032:Zinc / Q000032:analysis
D007220:Industrial Waste; D019216:Metals, Heavy; D012989:Soil Pollutants; D014873:Water Pollutants; D002104:Cadmium; D015636:Magnesium Chloride; D007854:Lead; D003300:Copper; D009532:Nickel; D015032:Zinc