【作者】 吴斌斌；

【导师】 石金辉；

【作者基本信息】 中国海洋大学 ， 环境工程， 2011， 硕士

【摘要】 重金属污染因其具有的持久性、生物富集和毒性而倍受关注,一直是国际环境科学界的热点研究课题之一。伴随着经济建设的快速发展,黄茅岛倾倒区日益增长的疏浚物倾倒是黄茅岛海域面临的主要环境问题之一。本文以黄茅岛倾倒区海域的监测资料,系统的研究了黄茅岛倾倒区海域的海水、沉积物、海洋生物中重金属的含量水平、分布特征及变化规律,探讨了沉积物中重金属与海水中重金属浓度的相关性,并线性回归出部分金属在海水中含量的计算公式,最后评价了表层沉积物中重金属污染物的潜在性生态风险。获得的研究成果和认识如下:(1)3次重金属元素调查中,表底层海水仅Pb含量超一类海水水质标准,Cu则在部分站点超标,Zn只在一个航次中个别站点超标,其它4种重金属均处于清洁水平。水平分布上多以北高南低、以H05为中心向周围递减为趋势,表底层大致相符。(2)表层沉积物重金属污染程度较轻,仅Cu在部分站点超一类海洋沉积物标准。总体上7种重金属在底质中的含量出现增长趋势,其中Cd增长幅度最大,Hg次之。水平分布上基本属于北高南低且以H05中心向周围递减为分布趋势。(3)沉积物主成分分析结果表明,大部分重金属元素对第一主成分均有较高的贡献率,Cr仅对第二主成分有相当高的贡献率。对表层沉积物中重金属相关分析表明,As与Zn、Cu、Cd、Pb、Hg ,Hg与Zn、Cd,Cu与Pb、Cd存在良好的相关性,系数在0.686~0.802之间。说明除了Cr,这几组物质之间有相同得地球化学来源和人为污染来源。(4)倾倒区海洋生物体中甲壳类及鱼类的生物质量良好,仅As一项超过参考值,其余金属均未超标。(5)考察了重金属在海水与沉积物中含量的相关性,Zn和As在沉积物与表底层海水间的含量均存在显著性相关,沉积物中的Cu和Hg对底层水有显著性相关。对存在显著相关性的金属采用线性回归方法归纳出重金属在沉积物和海水中关系公式。(6)采用地累计指数法、生态危害指数法和综合指数法对黄茅岛倾倒区沉积物重金属潜在生态风险进行了评价,评价结果显示该区域沉积物主要重金属污染物为Hg和Cu,总体污染程度处于中等偏低水平。更多还原

【Abstract】 Heavy metal pollution, owing to the characteristics of permanent, eco-toxicity and biological enrichment, has long been an important subject in the international environmental science fields. Along with the rapid development of economic construction, the increasing amount of sediments arising from dredge and other sources and its consequent disposal has been one of the major environmental promblems in the marine dumping site of Huangmao Island.Based on the monitoring data from the sea areas of Huangmao Island dumping site, the paper conducts a systematic research on the content, distribution and changing rules of heavy metal in seawater, sediments, and marine organisms of this area. In addition, the paper further explores the correlation between the content of heavy metal in sediments and the concentration of heavy metal in seawater, and then deduces out in linear regression a computational formula for calculating the content of some metals in seawater. Besides, the paper also carries out an evaluation concerning potential ecological risks of heavy metal pollutants in sediments of surface layers.The research results and cognitions obtained are listed as follows:(1) During three investigations on heavy metal elements, the only element in seawater that exceeds the quality standard of first class seawater is Pb. The content of Cu also exceeds the standard in some sampling points, while Zn exceeds the standard only in few sites of a single voyage. The content of other 4 types of heavy metal remain on a clean level. As for the horizontal distribution of these elements, the content in northern parts is higher than that of the southern parts in most occasions, presenting a declining trend with H05 as the center, so is the situation on the bottom layer.(2) Surface sediments are slightly contaminated by heavy metals, while Cu is the only element that has exceeded the standard of first class marine segments in some sites. Generally, 7 types of heavy metals are presenting a rising tendency in sediments, among which, Cd is the most remarkable one, with Hg taking the second place. Horizontally, the content of these elements in northern parts is basically higher than that in southern parts, presenting a declining distribution trend, with H05 as the center.(3) Analysis on the principal components of segments shows that, most heavy metals have contributed a lot to the first principal component, while Cr presents a high contribution rate only to the secondary principal component. Related analysis on heavy metals in segments also indicates that, there were good correlations between As and Zn, Cu, Cd, Pb, Hg, between Hg and Zn, Cd, as well as between Cu and Pb, Cd. The coefficient is fixed within the range of 0.686 ~ 0.802, which show this elements except Cr have the similar source of geochemistry and mam-made pollution.(4) The biological quality of crustaceans and fishes in the dumping area is on a normal level, while the only content that exceeded the reference value is As, and there are no other heavy metals that exceed the standard.(5) The correlation between the content of heavy metals in seawater and the content of heavy metals in segments is also inspected. The content of Zn and As in seawater and in seawater is taking on an obvious correlation. Moreover, Cu and Hg in segments are showing a remarkable correlation with seawater of bottom layer. In allusion to the heavy metals with obvious correlations, the formula of relationship between the content of heavy metal in segments and in seawater is deduced out with linear regression.(6) Geological accumulative index, ecological risk index, and comprehensive index are employed in evaluating the potential ecological risks of heavy metals contained in the segments of Huangmao dumping area. According to the evaluation result, the major heavy metal pollutants in the segments of this area are Hg and Cu, taking on a medium and lower pollution degree.更多还原