| 摘要: |
| 【目的】探明宁夏清水河重金属分布特征和污染情况。【方法】于2018年4月、7月和11月对清水河流域32个采样点的水体和表层沉积物中砷（As）、铬（Cr）、汞（Hg）和铅（Pb）的含量进行监测，采用主成分法和聚类分析法解析重金属污染来源，采用内梅罗综合指数法评价水体重金属污染情况，采用潜在生态风险指数评价表层沉积物重金属污染情况。【结果】清水河水体As、Pb、Hg、Cr的年平均量分别为3.68、0.37、0.23、69.27 μg/L，只有Cr超过地表水Ⅳ类标准，且4种重金属质量浓度整体变化为11月＞4月＞7月。表层沉积物中As、Cr、Pb、Hg的年平均量分别为标准值的68.2%、46.3%、39.9%、130%，只有Hg超过土壤背景值，4种重金属质量浓度整体变化为11月＞4月＞7月。内梅罗综合指数法评价清水河流域水体4种重金属污染程度依次为Cr＞Hg＞As＞Pb，Cr为最主要污染重金属。潜在生态风险指数法评价清水河流域表层沉积物4种重金属风险程度依次为Hg＞As＞Pb＞Cr，Hg是最主要的生态风险因子。主成分和聚类分析法都将水体和沉积物重金属分为3类，水体中Cr主要受人为控制因素，As、Hg、Pb主要受自然地质因素。沉积物中As、Cr、Pb主要受自然地质因素，Hg主要受人为控制因素。【结论】总体而言，水体中Cr和沉积物中Hg污染应当引起重视。 |
| 关键词: 流域；重金属；分布特征；风险评价 |
| DOI：10.13522/j.cnki.ggps.2019454 |
| 分类号: |
| 基金项目: |
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| Distribution Characteristics and Risk Assessment of Heavy Metals in Qingshui River Basin of Ningxia |
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LI Shilong, ZHAO Zengfeng, QIU Xiaocong, GUO Qi, WU Yueling
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1.School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China；2.School of Life Science, Ningxia University, Yinchuan 750021, China
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| Abstract: |
| 【Objective】Arsenic (As), chromium (Cr), mercury (Hg) and lead (Pb) in water and surface sediments at 32 sampling sites in Qingshui River basin were monitored in April, July and November 2018 to explore the distribution characteristics and pollution of heavy metals there. 【Method】Principal component method and cluster analysis method were used to analyze the source of heavy metal pollution. The Nemerow comprehensive index method was used to evaluate the heavy metal pollution in water. The heavy metal pollution of surface sediments was evaluated by the potential ecological risk index. 【Result】The results indicated that the annual average contents of As, Pb, Hg, and Cr in Qingshui River water were 3.68, 0.37, 0.23, and 69.27 μg/L, only Cr more than surface water Ⅳ class standard. And the four heavy metal concentrations decreased in the order of November＞April＞July. The annual average contents of As, Cr, Pb, and Hg in surface sediments were 68.2%, 46.3%, 39.9%, and 130% of the standard values, with only Hg exceeded the soil background value. And the four heavy metal concentrations decreased in the order of November＞April＞July. The degree of heavy metal contamination in the water of Qingshui River decreased in the following order of Cr＞Hg＞As＞Pb with the method of Nemerow comprehensive pollution index, and Cr was the main pollution heavy metal. Potential Ecological Risk Index Method was used for evaluating the risk of four heavy metals in surface sediments of Qingshui River basin. The order of risk degree was Hg＞As＞Pb＞Cr, and Hg was the main ecological risk factor. Both principal component and cluster analysis method classified water and sediment heavy metals into three categories. Cr in water was mainly controlled by human factors,while As, Hg, and Pb were mainly affected by natural geological factors. As, Cr, and Pb in the sediments were mainly affected by natural geological factors, and Hg was mainly controlled by human factors.【Conclusion】In general, Cr pollution in water and Hg pollution in sediments should be paid attention to. |
| Key words: basin; heavy metal; distribution characteristics; risk assessment |
