广西茅尾海海水和表层沉积物中重金属污染的调查及评价

Survey and Pollution Assessment of Heavy Metals in the Sea Water and Surface Sediments of Guangxi Maowei Sea

关键词:  茅尾海  海水  沉积物  重金属  污染评价

Key words:  Maowei Sea  seawater  sediments  heavy metal  pollution evaluation

摘要:

2011年10月从钦州茅尾海采集19个海水样品和16个沉积物样品,利用原子吸收光谱仪和原子荧光分光光度计测定钦州茅尾海表层沉积物中6种重金属元素(Cu、Pb、Zn、Cd、Hg、As)含量,采用单因子指数法和Häkanson生态风险指数法对海水及表层沉积物重金属污染特征及潜在生态风险性进行分析和评价。结果表明:该海域海水中Cu、Pb、Zn、Cd、Hg、As的含量(μg/L)变化范围分别为0.9~4.2、0~12.8、0~59.8、0.03~0.34、0~0.105、0.23~0.82,平均浓度(μg/L)分别为2.2、2.3、17.4、0.13、0.047、0.43,其中,海水中的Pb平均含量超过国家一类海水水质标准,各种重金属单因子污染程度依次为Pb > Hg > Zn > Cu > Cd > As。表层沉积物中的Cu、Pb、Zn、Cd、Hg、As的含量(μg/L)变化范围分别为(2.1~46.5)×10^-6、(13.9~34.0)×10^-6、(21.4~114.1)×10^-6、(0.06~0.40)×10^-6、(0.001~0.126)×10^-6、(3.77~19.63)×10^-6,平均含量(μg/L)分别为18.1×10^-6、26.3×10^-6、56.7×10^-6、0.19×10^-6、0.056×10^-6、9.60×10^-6。该海域重金属综合污染程度和潜在生态风险性均较低,重金属元素污染程度Cu > As > Pb > Cd > Zn > Hg,重金属元素对海洋生态系统潜在危害的影响程度Cd > Hg > As > Cu > Pb > Zn,沉积物中主要潜在生态风险因子为Cd、Hg。

Abstract:

19 seawater samples and 16 surface sediments samples were collected in Maowei Sea in October 2011.The heavy metals content in seawater and surface sediments was determined by atomic absorption spectrometry and atomic fluorescence spectrophotometer.The pollution status and the potential ecological risk of the heavy metals of surface sediments in Maowei Sea were studied by using the index technique of single factor and Häkanson ecological risk index.Results showed that the content range of Cu,Pb,Zn,Cd,Hg and As in surface seawater is 0.9~4.2,0~12.8,0~59.8,0.03~0.34,0~0.105,0.23~0.82μg/L,respectively and the average for each metal is 2.2,2.3,17.4,0.13,0.047,0.43μg/L,respectively.The concentration of Pb exceeded the standard of first grade seawater quality of China.The sequence of single factor index is Pb > Hg > Zn > Cu > Cd > As.The content range of Cu,Pb,Zn,Cd,Hg and As in surface sediments is (2.1~46.5)×10^-6,(13.9~34.0)×10^-6,(21.4~114.1)×10^-6,(0.06~0.40)×10^-6,(0.001~0.126)×10^-6,(3.77~19.63)×10^-6,and the average for each metal is 18.1×10^-6,26.3×10^-6,56.7×10^-6,0.19×10^-6,0.056×10^-6,9.60×10^-6 respectively.The result showed that the integrated contamination level of the heavy metals and the potential ecological risk of the heavy metal were both low in sediments of Maowei Sea.The order of the pollution degree was Cu > As > Pb > Cd > Zn > Hg,while,the order of the potential ecological risk was Cd > Hg > As > Cu > Pb > Zn.The Cd and Hg are the key potential ecological risk factors in surface sediments in Maowei Sea.