涠洲岛近岸海域重金属污染状况研究

Study on Heavy Metal Pollution in Coastal Waters of Weizhou Island

关键词:  涠洲岛  海水水质  海洋生物  重金属  污染指数  富集系数

Key words:  Weizhou Island  seawater quality  marine organism  heavy metals  pollution index  enrichment coefficient

摘要:

为了解涠洲岛近岸海域重金属元素Cu、Pb、Zn、Cd、Cr和Hg的污染现状，分别于2018年9月和2019年3月在涠洲岛近岸海域采集水样和生物样品，对其重金属含量进行分析，并计算各重金属的单项污染指数及其生物富集系数。结果显示，春季涠洲岛近岸海域的海水重金属含量均值排序为Zn>Pb>Cu>Cr>Cd>Hg，浓度为0.00-7.30 μg/L；秋季为Cu>Pb>Cd>Hg>Cr=Zn，浓度为0.00-4.18 μg/L。整体来看，秋季涠洲岛近岸海域的海水各重金属含量均在国家一类海水水质标准范围内，但春季涠洲岛东南面和北面的站点存在Pb超标现象。单项污染指数的计算结果表明，春季海水重金属污染严重程度依次为Pb>Hg>Zn>Cu>Cd>Cr，秋季为Pb>Cu>Hg>Zn>Cd>Cr，均未超出国家一类海水水质标准。春季海洋生物重金属含量均值排序为Zn>Cr>Cu>Hg>Pb>Cd，秋季为Zn>Cu>Cr>Hg>Pb>Cd。除Hg、Zn、Cr外，各重金属富集指数均未超过1 000，Hg、Zn、Cr在当地海洋生物体内存在比较明显的富集累积现象，其中Hg的富集程度显著高于其他重金属。总体来看，涠洲岛近岸海域水质状况良好，海洋生物受重金属污染程度低，均未超出国家水质及食品安全标准，但Hg、Zn、Cr出现了一定的生物富集现象，需要警惕。

Abstract:

To understand the pollution status of heavy metal elements Cu, Pb, Zn, Cd, Cr and Hg in the coastal waters of Weizhou Island，water and biological samples were collected from the coastal waters of Weizhou Island in September 2018 and March 2019, respectively.The heavy metal content of the samples was analyzed, and the individual pollution index and bio-concentration coefficient of each heavy metal were calculated.The results showed that the average content of heavy metals in the coastal waters of Weizhou Island in spring was in the order of Zn>Pb>Cu>Cr>Cd>Hg, and the concentration range was 0.00-7.30 μg/L, and in autumn it was Cu>Pb>Cd>Hg>Cr=Zn, and the concentration range was 0.00-4.18 μg /L.On the whole, the heavy metal contents in the coastal waters of Weizhou Island in autumn were all within the range of national first-class seawater quality standard in autumn, but in spring Pb contents exceeded the standard at the stations in the southeast and north of Weizhou Island.The calculation results of single pollution index showed that the severity of heavy metal pollution of seawater in spring was Pb>Hg>Zn>Cu>Cd>Cr, and in autumn it was Pb>Cu>Hg>Zn>Cd>Cr, all of which did not exceed the national first-class seawater quality standard.The average content of heavy metals in marine organisms in spring was in the order of Zn>Cr>Cu>Hg>Pb>Cd, and in autumn, it was Zn>Cu>Cr>Hg>Pb>Cd.Except for Hg, Zn and Cr, the enrichment index of each heavy metal did not exceed 1 000.Hg, Zn and Cr had obvious enrichment and accumulation in local marine organisms, and the enrichment degree of Hg was significantly higher than that of other heavy metals.Overall, the water quality in the coastal waters of Weizhou Island was in good condition, and the degree of heavy metal pollution of marine organisms was low, which did not exceed the national water quality and food safety standards.However, it is necessary to be alert to the bio-enrichment phenomenon of Hg, Zn and Cr.