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摘要：遵义市湘江河流经主城区，沿岸人口密度大，流域内生活污水和工农业活动产生的重金属汇入湘江河，为了解该河段的重金属污染分布特征及评价潜在生态风险，采用改进的 BCR 四步法提取并分析遵义市主城区湘江河 8 个表层沉积物样本中 9 种重金属元素的赋存形态，分别使用电感耦合等离子体原子发射光谱法测定 w(Cu)、w(Zn)、w(Pb)、w(Cd)、w(Cr)、w(Mn)和 w(Ni)，原子荧光光度法测定 w(As)和 w(Hg). 结果表明：①w(Cu)、w(Zn)、w(Pb)、w(Cd)、w(Cr)、w(Mn)、w(Ni)、w(As)和 w(Hg)的平均值分别为 64.89、292.83、59.78、1.22、34.89、1 605.44、10.98、4.74 和 0.64 mg/kg，除 w(As)外，其他重金属的平均值均高于贵州沉积物重金属背景值. ②w(Cu)、w(Zn)、w(Pb)、w(Cd)、w(Mn)和 w(Hg)在不同采样点间的变异系数分别为 54.91%、93.33%、78.73%、85.00%、106.46%和 93.44%，受人为活动的干扰较大. Cu 与 Cr、Zn 与Pb、Cd 与 Pb 之间存在极显著正相关关系(p<0.01)，其污染来源可能具有同源性. ③重金属的赋存形态在不同采样点间的空间分布差异较大，Cu、Pb、Cr、Ni、As 和 Hg 的主要赋存形态为残渣态，占比分别为 52.72%、59.31%、84.39%、79.09%、89.14%和 99.87%；Mn 以酸提取态为主，占比为 61.58%；Cd 以可氧化态为主，占比为 50.19%. 次生相与原生相分布比值法(RSP)评价结果显示，Cr、Ni、As 和 Hg 对湘江河水环境产生潜在生态危害的风险较低，Mn 和 Cd 的生态危害风险较高.
Abstract: The Xiangjiang River in Zunyi City flows into the Xiangjiang River through the main urban area and the densely populated coastline. The domestic sewage and the heavy metals produced in the industrial and agricultural activities are introduced into the Xiangjiang River. In order to understand the distribution characteristics of heavy metal pollution and evaluate the potential ecological risk, BCR four-step method was used to extract and analyze the occurrence patterns of nine heavy metal elements in eight surface sediment samples collected from the Xiangjiang River in the main urban area of Zunyi City. The contents of heavy metals (Cu), w (Zn) w (Cd), w (Cr), w (Mn) and w (Ni) were determined by atomic fluorescence spectrometry.The results showed that: ①w (Cu), w Zn, w Pb, w Cd, w Cr, w Mn, w Ni, w As and w Hg were 64.89, 292.83, 59.78, 1.22, 34.89,1 605.44,10.98,4.74 and 0.64 mg / kg, respectively, with the exception of w (As), the average values of other heavy metals were all higher than the background values of heavy metals in sediments of Guizhou.②w (Cu), w (Zn), w The coefficients of variation of w (Cd), w (Mn) and w (Hg) were 54.91%, 93.33%, 78.73%, 85.00%, 106.46% and 93.44% at different sampling points respectively, which were greatly disturbed by human activities Cu and Cr There was a significant positive correlation between Zn and Pb, Cd and Pb (p & lt; 0.01), and its source of pollution may be homologous.③The distribution of heavy metals in different sampling sites showed a large spatial distribution, with Cu, The main speciation of Pb, Cr, Ni, As and Hg was residual state, accounting for 52.72%, 59.31%, 84.39%, 79.09%, 89.14% and 99.87%, respectively. (61.58%), while Cd was mainly oxidizable, accounting for 50.19% .The evaluation of secondary phase and primary phase distribution ratio (RSP) showed that Cr, Ni, As and Hg had potential ecological risks to the water environment of Xiang River The risk of Mn and Cd is higher.