近岸海域贝壳与海水重金属含量的相关性研究

Study on Heavy Metal Content in Oyster Shell and Its Relevance to Sea Water

近海海域易于受到城市工业等人类活动的污染,重金属污染是其中之一,持续的低度污染也会造成近海生物体内污染物累积,影响海域渔业和生态环境。通过对大连周边6个海区内采集的牡蛎壳体分析测定发现,壳体中重金属的含量与该海区海水中重金属含量线性相关,其中Zn、Cd、Pb和Cu的相关系数分别为0．9430、0．9822、0．9930、0．9815,生物富集系数在1000左右。实验分析手段采用二阶微分阳极溶出伏安极谱,支持电解液为pH4．0～4．5的Hac-NaAc缓冲溶液,标准偏差RSD=0．11～1．16,实验回收率93～105%。研究结果表明,(1)牡蛎壳体可以替代贝类软组织作为监测海域环境的载体,指示海域环境重金属的变化情况; (2)牡蛎壳体层状的生长过程与同时期水质的状况密切相关,层状物理结构便于分层分析,通过本实验相关性的验证,完全有可能建立一种海水水质短期历史追溯的技术方法。

Heavy metal pollution of coastal water caused by human being activities like city industry becomes a hot topic nowadays. Continuing contamination even in low concentration of heavy metal can also cause coastal biotic accumulation, thus it impacts on the seawater environment as well as the fishery development. In this study, six coastal sites around Dalian were investigated by determination of the metal contents in the oyster shell. In comparison with seawater, it was found that the content of heavy metal in oyster shell is dosely in agreement with the concentration of metal in seawater. The relative coefficients for metal Zn, Cd, Pb and Cu are 0.9430, 0.9822, 0.9930 and 0.9815, respectively. The bio-accumulating rates are about 1000. All the experimental data of heavy metal were measured using second-order differential anodic striping polarmetric method. The running electrolyte solution was the HAc-NaAc buffer. The relative standard division （RSD） was among 0.11 - 1.16, and the reproducing rate was 93 -105%. In condusion, firstly, the oyster shell is an effective indicator for water quality concerning heavy metals instead of the seashell tissue. Secondly, k is possible to trace back to a short-term history of water environment by investigating the detail layers of oyster shell, because each of layer reflects a specific past time