2010年湄洲湾北部海区表层沉积物中重金属的分布特征和污染评价

Distribution and Pollution Assessment of Heavy Metals in Surface Sediments in the North of Meizhou Bay in 2010

于2010年10月对湄洲湾北部海区表层沉积物质量进行了调查,采用原子吸收和原子荧光分光光度法对沉积物Cu、Ni、Zn、Cd、Cr、Pb、As、Hg的含量进行了测定,并利用污染指数法和潜在生态风险指数法对调查海区表层沉积物重金属的污染状况进行了评价。结果表明:(1)海区Zn、Cr部分站位超海洋沉积物质量一类标准,符合二类,其余重金属元素含量均符合一类标准;(2)重金属元素同粒度的相关性分析及结果表明,Cu、Ni、Zn、Cr四种元素可能来源相似,Cd、Pb、As、Hg四种元素来源各异且与以上Cu、Ni、Zn、Cr四种元素来源存在差异;重金属主要来自潮流运动携入、工业排污、生活污水及海上航运;(3)调查海区污染指数和潜在生态风险指数评价结果表明,湄洲湾北部表层沉积物重金属整体处于中等污染水平,潜在生态风险轻微。

In October 2010, the quality of surface sediments was investigated in the north of Meizhou Bay. The contents of eight heavy metals(Cu, Pb, Zn, Cd, Ni, Cr, As, Hg) were determined by AAS and AFS(Atomic absorption spectrophotometer and Atomic fluorescence spectrometer), and the pollution index and potential ecological risk index were used to evaluate the pollution level and potential harmful effect of heavy metals. The results indicated that,(1) the contents of Zn, Cr in some sites of sea area exceeded the first class of GB18668-2002, which were at class 2 of the marine sediment quality, and the contents of others did not exceed the first class;(2) correlation analysis showed that the four elements of Cu, Ni, Zn, Cr may have similar pollution sources, and the four elements of Cd, Pb, As, and Hg originated from different sources and differed from the sources of Cu, Ni, Zn, and Cr;the inputs with tidal movement, the industrial and domestic waste water discharge and the marine traffic were the main sources of heavy metals;(3) the results of pollution index and potential ecological risk index analyses revealed that, in the whole, the heavy metals in the studied area were in a moderate degree of contamination and slight ecological risk.