无尾河下游湿地重金属污染评价

Assessment of heavy metal pollution of wetlands at downstream of an inland river

  • 摘要: 以无尾河下游漫流区———向海地区沼泽湿地为研究对象,通过对沼泽垂直剖面的精细采样,将放射性核素精确计年与重金属污染评价相结合,进行高分辨率剖析。在对其典型剖面沉积物重金属元素进行Al归一化的基础上,应用上下层比较法、富集系数法和地累积指数法3种评价方法对沉积物重金属污染富集水平及污染时序进行分析比较。结果表明,沼泽湿地沉积物表层已明显富集了重金属元素,达一定污染水平,这显示近20a霍林河流域上、中游人类活动对下游湿地的扰动增强。

     

    Abstract: Heavy metal pollution assessment has been successfully applied to studies on river,lake,ocean,and soil environments,but not too much on marshes,especially on time sequence of heavy metal pollution.Sediment can be considered the sink and end-result area for the heavy metals imported into water.Here a case study was reported of the Xianghai marsh at downstream of an inland river—Huolin River.High resolution analysis of the samples gathered from profiles in the marsh was performed with the aid of radionuclide timing and heavy metal pollution assessment,and based on normalization of heavy metals to aluminum in sediment in the typical profiles,heavy metal pollution and enrichment levels and time sequence were analyzed and compared using the methods of comparison between upper and lower layers,sediment enrichment factor(KSEF),index of geoaccumulation(Igeo).The results showed that within the upper layer of the profiles,significant enrichment of heavy metals was observed up to the level of pollution,indicating that the disturbance of the wetlands downstreams caused by human activities in the upper and middle reaches of Huolin River has been intensifying in recent 20 years.

     

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