渭河陕西段水体重金属污染现状及其来源探析

Heavy metal pollution and source analysis of Weihe River in Shaanxi Province

  • 摘要: 基于重金属及常规监测指标实测数据,对渭河陕西段水体重金属的污染现状进行评价,利用主成分分析等对重金属(Hg、As、Pb、Cd、Cr、Ni、Ca和Zn)与常规监测指标(NH3-N浓度、COD、EC、DO浓度和pH)的相关性及其来源进行研究。结果表明:渭河陕西段水体中As、Pb、Cd、Cr、Cu、Zn浓度均在GB 3838—2002《地表水环境质量标准》Ⅰ~Ⅱ类标准限值内,Ni浓度低于《集中式生活饮用水地表水源地特定项目》标准限值;渭河陕西段水体存在Hg污染。重金属与常规监测指标有不同程度的相关性,其中As、Cr、Ni与NH3-N呈显著正相关;As、Pb、Cd与EC呈极显著正相关;As与DO呈极显著负相关。主成分分析表明,第一主成分主要包括As、Pb、Cr、Ni、Cu,与NH3-N同源,主要与工业、生活等人为活动污染有关;第二主成分主要包括Cd和Zn,主要为地球化学来源。

     

    Abstract: Based on the measured data of heavy metals (Hg, As, Pb, Cd, Cr, Ni, Cu and Zn) and related routine monitoring indexes (NH3-N, COD, EC, DO and pH), the heavy metal pollution of the Weihe River in Shaanxi Province was evaluated according to the Environment Quality Standards for Surface Water (GB 3838-2002), and then the heavy metals sources in the region studied by principal component analysis and correlation analysis in and between the heavy metals and the routine monitoring indexes. The results indicated that the contents of As, Pb, Cd, Cr, Cu and Zn of the Shaanxi section of the Weihe River were below the standard limits for category Ⅰ or Ⅱ surface water, the content of Ni was below the limit of specific items for the drinking water and surface water sources, and the river was polluted at a certain degree by Hg. Heavy metals were correlated with routine monitoring indexes in different degrees, in which As, Cr, Ni had significant positive correlations with NH3-N, As, Pb, Cd showed highly significant positive correlations with EC, while As showed a significant negative correlation with DO. According to principal component analysis, the first principal component mainly included As, Pb, Cr, Ni, Cu, all were homology with NH3-N, and they were mainly from various human activities including of industry and life. The second principal component mainly included Cd and Zn, being of the geochemical sources.

     

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