中国东部海域细颗粒沉积物中重金属源汇效应和其对人类活动响应

发布时间：2018-06-25 09:14

本文选题：细颗粒沉积物 + 重金属　；参考：《中国海洋大学》2014年博士论文

【摘要】：中国东部海域接受大量的来自河流的沉积物，是陆海相互作用强烈的场所。百年的工业化进程中，特别是改革开放以来，大量的重金属污染通过河流和大气沉降等途径进入到东部海域，并最终被保存在该海域沉积体中。沉积体中重金属的研究，不仅可以了解人类活动对海域的影响，重建东部海域重金属污染历史，而且可以用作了解东部海域源汇作用的重要的指标，分析入海物质源汇过程和效应。基于采自东海、黄海的5根沉积物岩心和102个表层沉积物样品，采用激光粒度分析、ICP-AES(MS)元素和稳定同位素分析、多道γ谱分析系统等对沉积物进行了粒度、常量元素、微量元素及重金属以及同位素分析，揭示了研究区重金属时空发育特征，建立了高分辨重金属沉积记录，，探讨了重金属源汇过程和效应。取得以下主要成果：通过对东海和南黄海表层沉积物中重金属含量的测定，获得了东海和南黄海细颗粒沉积物中重金属的空间分布规律。东海和南黄海的细颗粒沉积物中Cr、Cu、Ni、Pb、V和Zn的空间分布具有相似的变化规律：东海呈现由近岸沿东南向远岸含量逐渐降低的变化趋势；南黄海呈现由西向东含量逐渐增加趋势。利用富集因子、地质累积指数的方法对研究海域底质沉积物的质量进行了环境质量评价，表明Cr、Cu、Ni和V处于无污染状态，而Zn和Pb存在一定程度的污染。尽管Pb和Zn存在一定程度的无污染，研究区海域所面临的生态风险是轻微的。建立了中国东部陆架近160年来的高分辨重金属沉积记录，它包含3个阶段。第一阶段从1860到1930,铅和锌的富集因子的值几乎保持不变,而在该时间段内中国主要为一个农业国家，这表明了在这个时间段内铅和锌的含量可以作为该海域的背景值。在第二阶段(1940年代-1980年代),铅和锌富集因子的值稳步增加,这表明了东海近岸海域受到人为活动的影响在增强。第三个阶段（1980年代—2009）在1980年代初期以后,人为活动对东海近岸海域的影响显著的增强。尽管东海近岸海域中重金属含量较高，但是在最近160年来，其面临重金属所带来的生态风险轻微。东海和南黄海细颗粒沉积物中Cu、Cr、Ni、Pb、V和Zn的单位面积埋藏通量研究表明：东海是重金属的重要汇聚场所，其细颗粒沉积物中重金属的埋藏通量约占所研究海域的79～82%；南黄海海域是重金属的次要汇聚场所，细颗粒沉积物中重金属的埋藏通量仅占所研究海域的21%～27%。尽管输入到研究海域的重金属污染物来源复杂，其中金属冶炼、煤炭、含铅汽油燃烧和水泥工业等可能是东海近岸海域中铅的主要人为来源。通过铅同位素特征值的对比，东海近岸海域沉积物中的铅相当一部分来自于煤炭燃烧。
[Abstract]:In the process of industrialization, especially since the reform and opening up, a large amount of heavy metal pollution has been entered into the eastern sea area through rivers and atmospheric sedimentation, and is eventually preserved in the sediments of the sea area. Heavy metals in the sedimentary bodies. The study not only can understand the influence of human activities on the sea area, rebuild the history of heavy metal pollution in the eastern sea area, but also can be used as an important indicator to understand the source and sink of the eastern sea area, and analyze the process and effect of the source and sink of the material into the sea. Based on the East China Sea, 5 sediments core and 102 surface sediment samples in the Yellow Sea are used with laser particles. Degree analysis, ICP-AES (MS) element and stable isotope analysis, multi channel gamma spectrum analysis system, etc. have been used to carry out grain size, constant elements, trace elements and heavy metals and isotopic analysis. The characteristics of space-time development of heavy metals in the study area are revealed, high resolution heavy metal deposition records are established, and the process and effect of heavy metals source and sink are discussed. The following main achievements:
By measuring the heavy metal content in the surface sediments of the East China Sea and the South Yellow Sea, the spatial distribution of heavy metals in the fine granular sediments of the East China Sea and the South Yellow Sea is obtained. The spatial distribution of Cr, Cu, Ni, Pb, V and Zn in the fine sediments of the East China Sea and the South Yellow Sea has a similar variation rule: the East China Sea appears from the southeast to the far shore in the East China Sea The South Yellow Sea gradually increased from west to East.
The quality of the sediment in the sea area was evaluated by the method of enrichment factor and geological accumulation index. It showed that Cr, Cu, Ni and V were in the non pollution state, while Zn and Pb had some pollution. Although there was no pollution in Pb and Zn to a certain extent, the ecological risk faced by the sea area of the study area was slight.
A high resolution heavy metal deposition record for the East China shelf for nearly 160 years has been established. It contains 3 stages. The first stage is from 1860 to 1930. The value of the enrichment factor of lead and zinc is almost unchanged. In this period, China is mainly an agricultural country, which indicates that the content of lead and zinc within this time period can be used as the sea area. Background value. In the second stage (1940s -1980 years), the value of lead and zinc enrichment factors increased steadily. This indicates that the impact of artificial activities in the offshore waters of the East China Sea is enhanced. The third stages (1980s - 2009), after the early 1980s, significantly enhanced the impact of human activities on the East China Sea near shore. The content of heavy metals is high, but in recent 160 years, the ecological risk brought by heavy metals is slight.
The study on the burial flux per unit area of Cu, Cr, Ni, Pb, V and Zn in the fine particulate sediments of the East China Sea and the South Yellow Sea indicates that the East China Sea is an important gathering place for heavy metals, and the buried flux of heavy metals in the fine sediment is about 79 ~ 82% in the studied area, and the South Yellow Sea is a secondary gathering place for heavy metals and heavy gold in fine grain sediments. The buried fluxes of the genus accounted for only 21% to 27%. of the studied sea area.
Although the sources of heavy metal pollutants entered into the sea area are complex, metal smelting, coal, leaded gasoline combustion and cement industry may be the main anthropogenic sources of lead in the offshore waters of the East China Sea. By comparison of the characteristics of lead isotopes, a considerable portion of the lead in the sediments of the offshore waters of the East China Sea comes from coal combustion.
【学位授予单位】：中国海洋大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P736.21;X55

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