通过对东北地区污染农田黑土剖面的取样调查分析,对重金属Cd、Pb、Cu、Zn在农田黑土中的污染状况及其迁移特征进行了对比研究,并就BCR(the Comm un ity Bureau of R eference)连续提取法在农田土壤重金属污染评估中的应用进行了探讨。结果表明,重金属的迁移率大小依次为:Cd>Cu>Pb>Zn,Cd的酸可溶态占全量的比率高于其它重金属。Pb的酸可提取态浓度随土壤深度增加而增大,公路附近土壤中Pb、Cu及城市郊区土壤中Cd、Pb和Zn的氧化物结合态含量均随土壤深度的增加而升高,已存在向下迁移的趋势。4种重金属有机结合态在采样区土壤中基本都表现为耕层高于非耕层。研究表明,应用BCR连续提取法有助于确定土壤重金属污染以及重金属向下迁移状况,借助该法可以有效、可靠地对土壤重金属污染进行评估。
Ecotoxicity and bioavailability of cadmium(Cd)to the maize(Zea mays L.)and the soybean(Glycine max(L.)Merr.)were investigated by acute toxicity experiment in the laboratory with black soil.Ecotoxicity and bioavailability of Cd were quantified by calculating the median effective concentration(EC50)and bioaccumulation factor(BAF).The measurement endpoints used were seed germination and seedling growth(shoot and root).The results showed that concentrations of Cd in the soil had adverse effect on the growth of roots and shoots.Seed germination was not the sensitive indicator for the ecotoxicity of Cd in the soil,while the growth of roots was the most sensitive measurement endpoint.Absorbability and transport of Cd in plants depended on the test crop species and Cd concentrations in the soil.The maize retains more Cd in its roots,while the soybean transports more Cd to the shoots from roots.
