埕岛油田海域重金属含量分布与生态环境质量评价

根据2009年埕岛油田海域环境调查资料,分析了海域内海水和表层沉积物中重金属的含量分布,并对其生态环境进行了质量评价和生态风险评价。结果表明:调查海域海水和表层沉积物中重金属的含量总体水平较低,均优于海水质量Ⅱ类标准和海洋沉积物质量Ⅰ类标准。除海水中Zn、Hg和表层沉积物中Cu外,海域内重金属的分布差异性较小,近岸重金属总量略高于远岸。质量评价表明,调查海域海水整体上为清洁水平,表层沉积物为较清洁水平,后者污染程度较前者偏重。生态风险评价表明,各站位表层沉积物均存在中低度的生态风险,部分站位As、Cu、Pb、Cr将偶尔发生不利生物毒性效应,7种重金属的生物毒性大小依次为:As>Cr>Zn>Pb>Cu>Hg>Cd。

Distributions and ecological assessment of heavy metals of Chengdao Oilfield sea areas

Based on the data of environmental survey obtained from Chengdao Oilfield sea areas in 2009,the distributions patterns of heavy metals in the seawater and surface sediments were analyzed.Environmental quality and ecological risk assessment of heavy metals in the investigated sea areas were also carried out.The results were summarized as follows.Overall,the contents of seven heavy metals in the seawater and surface sediments were low in the investigated sea areas.They were below the second degree of Sea Water Quality Standard and the first degree of Standard for Marine Sediments Quality respectively.In addition to Zn,Hg in the seawater and Cu in the surface sediments,the distributions patterns of heavy metals were almost the same.The total contents of heavy metals were slightly higher in the offshore than the other areas.The result of environmental quality assessment showed that the contents of heavy metals in the seawater belong to the grade of "green" and the contents of heavy metals in the surface sediments belong to the grade of "less green".The pollution level of the surface sediments was worse than the seawater.The ecological risk assessment of heavy metals indicates that the surface sediments had low to medium potential for biological toxicity effect.The values of As,Cu,Pb and Cr indicate they occasionally had adverse biological toxicity effect at some stations.The ecological risk intensity caused by different metals was: As>Cr> Zn>Pb>Cu>Hg>Cd.