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.