兰州市城关区街尘重金属的分布特征、赋存形态及环境风险评价

发布时间：2019-02-11 15:03

【摘要】：对兰州市城关区地表灰尘中Cu、Zn、Pb、Cr、Cd 5种重金属的质量分数及存在形态进行分析研究.结果表明:兰州市城关区街尘中的Cu、Zn、Pb、Cr、Cd的质量分数分别是8.568×10~(-5)、2.274×10~(-4)、9.636×10~(-5)、9.478×10~(-5)、8.40×10~(-7),均高于世界、中国、兰州市土壤元素背景值,但在全国范围内处于中等偏下水平.商业区Cu、Pb、Cr质量分数最高,居民区Zn、Cd质量分数最高,各功能区之间街尘重金属元素的质量分数不存在显著差异.Cu、Zn、Pb、Cr在街尘中主要以残渣态形式存在,Cd以铁锰氧化物形式占比最高.5种重金属的生物有效性为CdZnCu、CrPb.潜在生态风险评价法结果表明商业区、居民区和高校校园街尘重金属达到中等水平潜在生态危害,其中Cd污染贡献最大.
[Abstract]:The mass fractions and forms of five Cu,Zn,Pb,Cr,Cd heavy metals in surface dust of Chengguan District of Lanzhou City were studied. The results show that the mass fraction of Cu,Zn,Pb,Cr,Cd in street dust in Chengguan District of Lanzhou is 8.568 脳 10 ~ (-5), 2.274 脳 10 ~ (-4), 9.636 脳 10 ~ (-5), 9.478 脳 10 ~ (-5), 8.40 脳 10 ~ (-7), respectively. The background value of soil elements is higher than that of the world, China and Lanzhou, but it is at the middle and lower level in the whole country. The content of Cu,Pb,Cr in commercial district was the highest, and that of Zn,Cd in residential area was the highest. There was no significant difference in the mass fraction of heavy metal elements in street dust among different functional areas. Cu,Zn,Pb,Cr existed mainly in the form of residue in street dust. The Cd is the highest in the form of iron and manganese oxides. The bioavailability of 5 heavy metals is CdZnCu,CrPb.. The results of potential ecological risk assessment showed that heavy metals in commercial areas residential areas and campus streets reached a moderate level of potential ecological hazards in which Cd pollution contributed the most.
【作者单位】：兰州大学资源环境学院;天津市水务局水文水资源勘测管理中心;
【基金】：国家自然科学基金项目(51178209,91025015) 中央高校基本科研业务费专项资金项目(Izujbky-2014-279,lzujbky-2014-208)
【分类号】：X513;X823

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