【作者】 张玉凤；

【导师】 关道明；

【作者基本信息】 大连海事大学 ， 环境科学， 2008， 硕士

【摘要】 锦州湾是我国受重金属严重污染的海湾之一,因经济的迅速发展,大量的工业、农业、生活污水被排放入海,使得海湾环境污染日趋严重。沉积物是重金属污染物的最终汇聚场所,当外界环境条件改变时,沉积物中吸附的重金属污染物会再度释放引起二次污染,对整个海湾生态系统带来严重威胁。本文对锦州湾14个表层沉积物及其赋存形态中重金属元素的分布以及生物可利用性等方面进行研究,并分析评价了锦州湾表层沉积物的重金属污染状况。论文主要内容如下:建立了沉积物及其各赋存形态以及生物样品中重金属元素的ICP-MS分析测定方法,实验中采用碰撞/反应池技术消除干扰,获得的分析参数(仪器检测限、方法检测限、准确度和精密度)均能达到实验测定要求。分析了锦州湾14个沉积物样品及其各赋存形态中16种重金属元素的含量,同时选择其中有浓度梯度的沉积物样品进行生物富集的实验研究。结果表明:在靠近葫芦岛锌厂排污口的沉积物样品中重金属含量最高;沉积物样品中Cd、Zn、Pb和Cu等元素大部分以非残渣态存在,易于进入水相或被生物所利用;菲律宾蛤仔对锦州湾沉积物样品中Cu、Zn、As、Pb、Cd元素有明显的富集作用,其他元素的富集作用相对较弱。采取多种评价方法对锦州湾重金属的污染状况进行评价,结果表明:研究区域存在极重的潜在生态风险。锦州湾的重金属污染大多数来自人为输入污染,污染严重的金属元素为Cd、Zn、Pb、Cu、As,并且,研究区域中,Cd和Zn的可交换态和碳酸盐结合态、Pb和As的可交换态、碳酸盐结合态、Fe-Mn氧化物结合态和有机质结合态以及Cu的可交换态和有机质结合态为沉积物中的生物可利用形态,并且Cd、Zn、Pb、Cu、As的生物可利用态在沉积物样品中均有一定分布。研究区域的最终评价结果表明,锦州湾是受重金属污染的高风险海域。更多还原

【Abstract】 Jinzhou Bay was one of areas suffering from serious heavy metal pollution in China. Because of the rapid development of economy, lots of industrial, agricultural and domestic wastewaters were discharged into the coastal area, and the marine ecological environment was seriously deteriorated. Sediment was a major reservoir for heavy metals, when the environment condition was changed (the increase of salinity, the changes of oxidation-reduction condition and pH descended etc.), the metals adsorbed on the particulates were released again, and the entire coastal ecosystem was seriously threatened. The present paper was based on fourteen surface sediment samples collected in Jinzhou Bay, the heavy metal contents in the samples were determined, and the heavy metal speciation analysis in the sediment samples was studied by Tessier sequential extraction procedure, meanwhile, the research on bioaccumulation of heavy metals in five sediment samples was conducted by using the Ruditapes philippinarum as the test organism. The evaluation of heavy metal pollution in the surface sediment of Jinzhou Bay was discussed in this paper.In the present paper, analytical methods for determination of heavy metals in sediments, extraction phases and biological samples were established by ICP-MS. The collision reaction cell was employed to eliminate the polyatomic interferences arising from the environmental samples with complex matrixes. The analytical parameters (the instrument detection limits, the method detection limits, accuracy and precision) were proved to be satisfactory.In order to assess the heavy metal pollution in surface sediment, the distribution of sixteen heavy metal elements were determined in sediments at fourteen sampling stations in Jinzhou Bay. Metal contents in the sediments near the zinc plant effluent were higher than other samples. Meanwhile, the metals of Cd, Zn, Pb and Cu in the sediment samples were primarily associated with the non-residual fraction, and Cu, Zn, As, Pb and Cd were accumulated significantly in the research on bioaccumulation with Ruditapes philippinarum.After reviewing the many assessment methods used at home and abroad, several assessment methods were used for evaluating the pollution level of Jinzhou Bay in the present paper. The potential ecological risk of the sediment samples was serious in Jinzhou Bay, Cd, Zn, Pb, Cu and As were the primary contaminated elements in the sediment samples, and metals of Cd, Zn, Pb, Cu and As were suggested significant anthropogenic impact. The bio-available constituents of Cd/Zn fractions in the surface sediment was comprised of exchangeable and carbonate fractions, and Pb/As bio-available fractions were made up of non-residual fraction, the bio-available constituents of Cu fractions in the surface sediment was composed of exchangeable and organic matter fractions. In a word, Jinzhou Bay was a high ecological risk region.更多还原