河北省典型污灌区土壤和植物重金属累积特征研究

利用田间调查、对比采样和室内分析相结合的方法，研究了河北省典型污灌区土壤和农作物的重金属污染状况。结果表明：与清灌区相比，污灌区土壤的Cu、Zn、Pb、Cd和Cr均有不同程度的积累，且存在个别样点土壤重金属Cd超标的情况。污灌区土壤Cd和zn含量沿汶河流域自上向下呈明显的下降趋势。4个污灌县土壤主要以Cd累积比较明显。玉米秸秆中的Cu、Zn、Pb、Cd和Cr含量均高于籽粒；小麦秸秆中的Pb、Cd和Cr含量均高于籽粒，Cu含量与籽粒基本相当，Zn含量则明显低于籽粒。污灌区重金属从土壤向小麦籽粒的迁移能力高于玉米。玉米和小麦籽粒对重金属的吸收能力均为Zn〉Cd〉Cu〉Pb〉Cr。

Characteristics of Heavy Metals Accumulation in Soil and Crops in Typical Sewage Irrigation Area of Hebei Province

The heavy metal content in soil and main crops were studied by the methods of field investigation, sampling and laboratory analysis in typical sewage irrigation area of Hebei province. The results showed that the accumulation levels of Cu, Zn, Pb, Cd and Cr were different in sewage irrigation area soil compared with irrigated areas, and Cd content in individual sample exceeded the 2nd criteria of environmental quality standard for soil. The content of Cd and Zn in soil declined obviously from the upriver to downriver along the Xiao river basin. The Cd content in soil accumulated obviously in four major sewage irrigation Counties. The content of Cu, Zn, Pb, Cd and Cr in corn stalks were higher than in grains. The content of Pb, Cd and Cr in wheat straw were higher than in grain, Cu content was basically equivalent with grains, Zn content was significantly lower than the grain. The ability of heavy metal transplanted from soil to wheat grains was higher than to corn in the sewage irrigation area. The capacity of heavy metals accumulated by corn and wheat grain were respectively followed by Zn 〉 Cd 〉 Cu 〉 Pb 〉 Cr.