广西铁山港邻近海域表层沉积物中重金属污染现状

Pollution Status of Heavy Metals in Surface Sediments near Tieshangang Bay Sea Area,Guangxi

关键词:  重金属  沉积物  潜在生态风险  铁山港  北部湾

Key words:  heavy metals  sediment  potential ecological risk  Tieshangang Bay  Beibu Gulf

摘要:

为阐明广西铁山港港口经济快速发展对海域生态环境带来的影响，基于广西铁山港湾海域19个站位表层沉积物地球化学测试分析，研究该海域中重金属元素Pb、Zn、Cu、Cd、Cr、Hg和As分布特征，并分析其潜在生态风险。结果显示，铁山港海域表层沉积物中Pb、Zn、Cu、Cd、Cr、Hg和As含量的平均值分别为10.7，37.0，10.4，0.07，25.7，0.042和9.42 mg·kg^-1，重金属的含量由高至低依次为Zn>Cr>Pb>Cu>As>Cd>Hg，其含量均符合国家海洋沉积物质量一类标准。除Cu外，重金属分布情况相似，其含量总体表现为港湾内高于港湾外。与其他区域相比，铁山港海域重金属含量明显低于广西北部湾其他港口区域，处于较低水平。铁山港重金属单因子污染程度依次为Cu>As>Zn>Pb>Hg>Cd>Cr，沉积物中重金属的潜在风险程度较低；生态危害影响依次为Hg>Cd>As>Cu>Pb>Cr>Zn，处于低潜在生态风险的范畴，反映了研究海域优良的底质生态环境，但受人类活动影响，港湾内沉积物重金属总体污染程度和潜在风险指数较高，应引起警惕。

Abstract:

In order to clarify the impact of the rapid economic development of Tieshangang Bay on the coastal marine ecological environment,based on the geochemical test and analysis of surface sediments at 19 stations in the sea area of Tieshangang Bay in Guangxi,the distribution characteristics of heavy metals Pb,Zn,Cu,Cd,Cr,Hg and As in this area were studied and the potential ecological risks were analyzed.The results showed that the average contents of Pb,Zn,Cu,Cd,Cr,Hg and As in the surface sediments of Tieshangang Bay were 10.7,37.0,10.4,0.07,25.7,0.042 and 9.42 mg·kg^-1,respectively.The contents of heavy metals showed the decreased trend from Zn>Cr>Pb>Cu>As>Cd>Hg,which were in line with the first class of national marine sediment quality standards.Except for Cu,the distribution of heavy metals was similar,and the content in the inner bay was generally higher than that outside the bay.Compared with other areas,the content of heavy metals in Tieshangang Bay was significantly lower than that in other port areas of the Guangxi Beibu Gulf,at a low level.The single factor pollution degree of heavy metals in Tieshangang Bay was arranged in the following order:Cu>As>Zn>Pb>Hg>Cd>Cr,and the potential risk of heavy metals in sediments was lower.The impact of ecological hazards was Hg>Cd>As>Cu>Pb>Cr>Zn,which was in the category of low potential ecological risk,reflecting the excellent sediment ecological environment in the study area.However,due to the influence of human activities,the overall pollution degree and potential risk index of heavy metals in sediments in the inner bay were relatively higher,which should cause enough vigilance.