Spatiotemporal distribution dynamics of heavy metals in water, sediment, and zoobenthos in mainstream sections of the middle and lower Changjiang River
Spatiotemporal distribution dynamics of heavy metals in water, sediment, and zoobenthos in mainstream sections of the middle and lower Changjiang River
复制标题
长江中下游干流河段水体、沉积物及底栖动物重金属时空分布动态
DOI：
10.1016/j.scitotenv.2020.136779
复制
发表时间：
2020-04-20
影响因子：
9.8
通讯作者：
Liu, Min
中科院分区：
文献类型：
--
作者：
Li, Rui;Tang, Xianqiang;Liu, Min
水体、沉积物和底栖动物是重金属迁移转化的重要载体和贮存介质。重金属在水体、沉积物和底栖动物中的分布特征可以反映其污染状况及其对水生态系统健康的潜在影响。本文根据铜的相关监测数据，长江武汉-上海段8个断面干流水体、表层沉积物和底栖动物中Zn、Pb、Cd、Ni、Mn、Hg、As的含量根据20世纪80年代以来长江（又称长江）不同环境介质中重金属分布的历史监测资料，系统分析了长江流域重金属时空分布动态、污染程度、以及与水体、沉积物和生物区系中重金属相关的环境风险，并研究了污染源变化以及水体和沉积物状况对重金属分布的影响。沃茨中重金属含量远低于《中国地表水环境质量标准》（GB 3838 -2002）Ⅲ类水质阈值：Cu、Cd沿干流分布不规则，且变化沿着方向明显。沉积物中Zn、Pb含量均超过其临界效应浓度，使生态系统面临污染风险：底栖动物中Zn、Cu的污染水平和生态系统健康风险较高，污染浓度大小依次为虾>螺>蟹。总的来说，三种环境介质中重金属含量的大小顺序为沉积物>底栖动物>水体.最后，与历史监测数据对比发现，受污染物排放和水沙条件变化的共同影响，长江中下游沉积物中Cd和Hg含量呈上升趋势，且沉积物中重金属平均含量在2000年代达到最大值。(C)2020爱思唯尔B. V.保留所有权利。
Water, sediment, and zoobenthos are crucial carriers and storage media for heavy metal migration and transformation. The distribution characteristics of heavy metals in water, sediment, and zoobenthos can reflect their pollution status and potential influences on the health of aquatic ecosystems. On the basis of monitoring data related to Cu. Zn, Pb, Cd, Ni, Mn, Hg, and As in mainstream water, surface sediment, and zoobenthos at eight sections- from Wuhan to Shanghai-of the Changjiang River (also known as the Yangtze River) and historical monitoring data on heavy metal distributions in different environmental media of the Changjiang River since the 1980s, this study undertook systematically analyzed the spatiotemporal distribution dynamics, pollution levels, and conesponding environmental risks related to heavy metals in water, sediment, and biota, and examined the effects of pollution source variations and water and sediment regimes on heavy metal distribution. Heavy metal concentrations in the waters were much lower than the water quality threshold of Grade Ill of the Chinese Surface Water Environmental Quality Standard (GB3838-2002): the concentrations of different heavy metals were irregularly distributed and varied significantly along the river mainstream: Cu, Cd. Zn, and Pb concentrations in sediment all exceeded their respective critical effect concentrations and exposed the ecosystem to pollution risks: the pollution levels of and ecosystem health risks posed by Zn and Cu in zoobenthos were high, with pollution concentrations ranked as shrimp > snails > crabs. In general, heavy metal concentrations in the three environmental mediums were ranked as sediment > zoobenthos > water. Finally, comparison with historical monitoring data revealed increasing Cd and Hg concentrations, with the average heavy metal concentration in sediment reaching its maximum value in the 2000s in the middle and lower reaches of the Changjiang River, which are subjected to the combined effect of pollutant emissions and changing water and sediment regimes. (C) 2020 Elsevier B.V. All rights reserved.