[Pollutant distribution in organo-mineral aggregates in topsoils from a site contaminated by organochlorine pesticides].
Four different soil particle-size fractions that is clay, silt, fine sand and coarse sand ( <2 microm, 2-20 microm, 20-200 microm, > 200 microm) from the topsoils in an organochlorine pesticide (OCP) field were separated by physical method to characterize the OCPs distribution in soils and to study the effect of organic matter and mineral composition in different separates on pollutants distribution. The results show that the concentrations of HCHs and DDTs in silt with 463.1 mg x kg(-1) and 1225.6 mg x kg(-1) are higher than those in coarse sand, 157.8 mg x kg(-1) and 384.5 mg x kg(-1), respectively. There is a significant correlationship between IgKoc. and the contents of HCHs and DDTs in clay. The analysis on X-ray diffraction of organo-mineral aggregates demonstrates that clay and silt have a much higher content of the clay minerals than those in coarse sand within the contaminated soils. There are some differences with different particle-size fractions in the content and composition of the clay minerals in organo-mineral aggregates, which affect the OCP distribution in soils to some extents. The results also suggest that the distribution of HCHs and DDTs in the particle with more pollutants in the site is similar to that in airborne particles. So the environmental behavior of OCPs in topsoils from the contaminated site should be paid more attention especially in ambient air-soil interaction.
Cong
Xin
X
School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, China. congxincx@yahoo.com.cn
Xue
Nan-dong
ND
Liang
Gang
G
Wang
Shi-jie
SJ
Zhu
Shu-quan
SQ
Li
Fa-sheng
FS
D002681:China; D003634:DDT / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
D010573:Pesticide Residues; D010575:Pesticides; D012989:Soil Pollutants; D003634:DDT; D011078:Polychlorinated Biphenyls