重金属在土壤-空心菜系统中的迁移分配

通过盆栽试验，研究了Cu，Zn，Pb和Cd单一与复合污染条件下在土壤-空心菜系统中的迁移分配情况.结果表明:单一和复合污染情况下，空心菜地上部重金属的富集系数大体表现为Cd>Zn>Cu>Pb，重金属转运系数则表现为Cd>Zn>Pb>Cu.与单一污染相比较，复合污染条件下，Cu，Zn，Pb和Cd富集系数下降，Cu的转运系数升高，而Zn，Pb和Cd的转运系数降低.单一污染条件下，随着土壤中重金属质量分数的增大，Cu的富集系数和转运系数都相应减小；Zn和Pb的富集系数增大而转运系数减少；Cd的富集系数增大，但转运系数变化很小.整体上看，复合污染条件下，土壤w(Cu)的增加使Zn，Pb和Cd在空心菜中的富集系数明显减小；土壤w(Zn)的增加使空心菜中Cd的富集系数明显减小；土壤w(Pb)的增加使空心菜中Cu的富集系数明显增大；土壤w(Cd)的增加使空心菜中Pb的富集系数明显增大. 

The Transfer and Distribution of Heavy Metals in Soil-Swamp Cabbage Systems

Pot experiments were conducted to study the transfer and distribution of Cu, Zn,Pb and Cd in soil-swamp cabbage systems under both mono-pollution and multi-pollution conditions.The results showed that under both mono-pollution and multi-pollution conditions, bioconcentration factors (BCF) of the four metals in the stem and leaf of swamp cabbage appeared as Cd>Zn>Cu>Pb, but transport factors (TF) appeared as Cd>Zn>Pb>Cu.Compared with the mono-pollution condition, BCF ofCu, Zn, Pb and Cd decreased; under the multi-pollution condition, TF of Cuincreased but TF of Zn, Pb, Cd decreased.Under the mono-pollution condition, BCF and TF of Cu decreased, BCF of Zn and Pb increased while TF decreased, and BCF ofCd increased but TF changed slightly with increasing heavy metal contents in the soil.In general, BCF of Zn, Pb, and Cd decreased obviously with increasingCu content in soil under the multi-pollution condition; BCF of Cd decreased obviously with increasing Zn content in the soil; BCF of Cu increased obviously with increasing Pb content in the soil; and BCF of Pb increased obviously with increasing Cd content in the soil.