福建安海湾五种重金属和砷在不同介质中的分布特征研究

Study on distribution characteristics of 5 heavy metals and As concentration in different medium of Anhai Bay

据2014年5月和8月福建安海湾9个站位的调查资料,分析海水、水中悬浮物和表层沉积物中Cu、Pb、Zn、Cd、Hg等5种重金属和类金属As的含量及分布特征,用单因子指数法、潜在生态危害评价法评价湾内重金属污染程度。结果表明,海水分布从湾顶往湾内和湾口逐渐降低,以湾顶值最高;水中悬浮物Cu、Pb、Zn、As、Hg含量以AH5站最高,Cd含量以AH6站最高,并向周边逐渐降低;表层沉积物含量从AH5站向湾内及湾口逐渐降低。部分站位海水和沉积物中Cu、Zn含量相对偏高,Pb、Cd、As、Hg含量均符合海水及沉积物质量标准的第一类要求。安海湾海域不同介质中悬浮物的含量最高,表层沉积物次之,海水的含量最低。水中悬浮物8月含量潜在生态危害程度远大于5月,以AH5站的潜在生态危害程度最强,主要潜在生态危害元素为Cd和Hg;表层沉积物以AH1、AH5站的潜在生态危害程度稍强,主要潜在生态危害元素为Cd,Hg次之。安海湾海域环境受到不同程度的重金属污染,陆源重金属污染物排放成为主要来源,本研究为安海湾海域生态环境防治提供科学依据。

According to the data of 9 stations of Anhai Bay in Fujian in May and August of 2014, we analysed the content and distribution on 5 heavy metals （Cu, Pb, Zn, Cd, Hg ） and metalloid As in seawater, suspended particulate matter of water and surface sediment, evaluated the heavy metals pollution degree by single factor index method and potential ecological risk index. Results showed that the seawater distribution gradually reduced from the top of the bay to inner bay and bay mouth with the highest value in site AH1. Suspended particulate matter in water of Cu, Pb, Zn, As, Hg content showed the highest value in site AH5 , Cd content in site AH6 was the highest, and decreased gradually to the surrounding sites. The content of surface sediment gradually reduced from site AH5 to inner bay and bay mouth. The content of CuN Zn in part sites of seawater and sediment were relatively high, Pb、Cd、As、Hg content were all in line with the requirements of the first class of sea water quality standard and sediments quality standards. The content in suspended particulate matter was the highest. In different mediums of Anhai Bay, the content in surface sediment was the second and the last one was in seawater. It was found that the potential ecological hazard risk degree in August of suspended matter analysis was far greater than that in May, potential ecological risk degree in site AH5 of Anhai Bay was the strongest, and the main potential ecological risk elements were Cd and Hg. According to potential ecological hazard analysis of the surface sediments, the potential ecological risk of AH1 and AH5 stations were more stronger in the bay and the main potential ecological risk elements were Cd and Hg. The waters environment of Anhai Bay has suffered heavy mental pollution in different degree, which indicated that the pollution of heavy metals was probably caused by land source pollution in Anhai Bay. This study for the gulf waters provides a scientific basis for prevention and control of ecological environment.