摘要
以西北某矿区为中心点,调查矿区周边玉米农田中土壤及玉米不同部位中铜(Cu)、镉(Cd)、镍(Ni)、铬(Cr)、铅(Pb)、汞(Hg)、锌(Zn)的含量,为评估重金属累积污染风险和实施污染土壤生态修复提供参考.结果表明,矿区附近种植玉米农用地耕植土中重金属Cr、Zn、Ni、Cu、Cd、Hg的含量与矿区中心点的距离呈显著负相关.玉米不同部位中重金属的含量水平为:Zn＞Cu＞Cr＞Ni＞Pb＞Cd＞Hg;重金属在不同部位中的最大富集系数为:玉米雄花序＞玉米叶＞玉米根＞玉米种皮＞玉米芯＞玉米茎＞玉米籽粒.Hg和Cd在玉米不同部位中的富集系数和转运系数均较高,应特别关注土壤中Hg、Cd污染风险给农田玉米种植带来的食品安全及生态安全风险.
Abstract
To find out heavy metals content and its distribution characters in soil and maize,a mining area in northwest China was chosen as the center,investigated the contents of cadmium(Cd),mercury(Hg),lead(Pb),chromium(Cr),copper(Cu),nickel(Ni)and zinc(Zn)in soil and different parts of maize around the mining area,provided reference for reasonable evaluation of heavy metals pollution and ecolog-ical remediation of contaminated soil.The results showed that there was a significant negative correlation between the content of heavy metals Cr,Zn,Ni,Cu,Cd,and Hg in the farmland soil and the distance from the center of the mining area.The contents of heavy metals in different parts of maize were Zn＞Cu＞Cr＞Ni＞Pb＞Cd＞Hg.The maximum enrichment coefficients of heavy metals in different parts of maize were as follows:male inflorescence＞maize leaf＞maize root＞maize husk＞maize cob＞maize stem＞maize grains.The enrichment and transport coefficients of Hg and Cd in different parts of maize are relatively high,and special attention should be paid to the risk of soil Hg and Cd pollution,as well as the food safety and ecological safety risks caused by maize cultivation in farmland.
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万方数据