段云莹, 裴绍峰, 廖名稳, 翟世奎, 张海波, 徐刚, 袁红明. 莱州湾表层沉积物重金属分布特征、污染评价与来源分析[J]. 海洋地质与第四纪地质, 2021, 41(6): 67-81. DOI: 10.16562/j.cnki.0256-1492.2020112601
引用本文: 段云莹, 裴绍峰, 廖名稳, 翟世奎, 张海波, 徐刚, 袁红明. 莱州湾表层沉积物重金属分布特征、污染评价与来源分析[J]. 海洋地质与第四纪地质, 2021, 41(6): 67-81. DOI: 10.16562/j.cnki.0256-1492.2020112601
DUAN Yunying, PEI Shaofeng, LIAO Mingwen, ZHAI Shikui, ZHANG Haibo, XU Gang, YUAN Hongming. Spatial distribution of heavy metals in the surface sediments of Laizhou Bay and their sources and pollution assessment[J]. Marine Geology & Quaternary Geology, 2021, 41(6): 67-81. DOI: 10.16562/j.cnki.0256-1492.2020112601
Citation: DUAN Yunying, PEI Shaofeng, LIAO Mingwen, ZHAI Shikui, ZHANG Haibo, XU Gang, YUAN Hongming. Spatial distribution of heavy metals in the surface sediments of Laizhou Bay and their sources and pollution assessment[J]. Marine Geology & Quaternary Geology, 2021, 41(6): 67-81. DOI: 10.16562/j.cnki.0256-1492.2020112601

莱州湾表层沉积物重金属分布特征、污染评价与来源分析

Spatial distribution of heavy metals in the surface sediments of Laizhou Bay and their sources and pollution assessment

  • 摘要: 基于2016年莱州湾32个站位表层沉积样的测试和分析并结合以往调研资料,探讨了Cu、Pb、Zn、Cr、Cd、As和Hg等7种重金属元素的含量、空间分布特征和相关性,并采用潜在生态风险法、地累积指数法和沉积物质量基准法对该区重金属污染状况进行了系统评价。结果表明,表层沉积物中重金属主要在黄河口以北、西南部小清河口及其东北部富集;Cr、Cd、Hg等与细颗粒沉积物相关,揭示重金属含量受沉积物粒度影响;而沉积物类型分布特征与莱州湾平均环流基本吻合,并与周围河口水动力和潮流显著相关。重金属污染评价结果表明:全部站位的重金属含量均低于PEL(可能效应水平),综合潜在生态风险为低风险;地累积指数评价结果表明:研究区约60%区域受到了Hg的污染,较多比例站位Cd(37.5%)和As(12.5%)显示为轻度污染。统计分析发现,Cu、Pb、Zn、Cd、As和Hg之间存在较为显著的正相关关系,其中Cu、Pb和Zn主要受地壳自然风化过程控制,而Cu和Zn还受有机碳含量的影响;Cd和As推测与人类活动相关;Cr的含量主要来源于地壳自然风化过程,人类活动影响次之。研究结果表明黄河和小清河很有可能是莱州湾西部和西南部表层沉积物的主要来源,该结果与以往研究结果基本一致。

     

    Abstract: Surface sediment samples were collected in 2016 at 32 stations in Laizhou Bay. Studies are devoted to the concentrations, spatial distribution patterns and interrelations of seven heavy metals (Cu, Pb, Zn, Cr, Cd, As and Hg). Comparison is made with previous investigations. The pollution status is evaluated systematically with potential ecological risk index (PERI), geoaccumulation index (Igeo) and sediment quality guidelines (SQGs). Our results show that the heavy metals in the surface sediments are mainly concentrated in the north of the Yellow River estuary, Xiaoqing estuary (the southwest) and the northeast of Laizhou Bay. Cr, Cd and Hg are obviously related with fine grain sediments, indicating the control of sediment grain size over heavy metal contents. The distribution patterns of sediment types are mostly consistent with the mean circulation in Laizhou Bay, and are significantly related to the hydrodynamics of surrounding estuaries and tidal currents. Results of heavy metal pollution assessment suggest that heavy metal contents at all stations are lower than the possible effect level (PEL), and the integrated potential ecological risk is low. Geoaccumulation index suggests that about 60% of the study area are polluted by Hg, lightly polluted by Cd (37.5%) and As (12.5%). Cu, Pb, Zn, Cd, As and Hg show significant positive correlations; Cu, Pb and Zn are mainly controlled by natural crust weathering process, while Cu and Zn are affected by TOC as well; Cd and As are presumed to be related to human activities; and Cr came mainly from the natural weathering process of the crust, in addition to some from human activities. Accordingly, the Yellow River and Xiaoqing River were likely to be the main sources of surface sediments in the west and southwest of Laizhou Bay, which is basically consistent with previous studies.

     

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