摘要: |
为研究七连屿海洋环境质量状况,于2017年8月在七连屿海域布设20个采样站位,共采集到22个表层海水样品及6个表层沉积物样品,通过原子吸收分光光度计及原子荧光分光光度计测定海水及沉积物中重金属(Cu、Pb、Zn、Cd、Cr、As、Hg)的含量,采用单因子评价法、综合污染指数法及相关性分析对水质重金属污染程度进行研究,并采用单因子评价法及Hankanson潜在生态风险指数法分别对沉积物质量及沉积物中重金属潜在生态风险进行评价。结果表明,2017年七连屿海域表层海水重金属含量CZn>CPb>CAs>CCr>CCu>CCd>CHg,部分站位海水铅含量超一类海水水质标准,但是综合污染指数小于1,该调查海域表层海水属于清洁型;海水中Zn-As、Cr-Cd含量之间存在显著负相关关系,此两组元素存在明显异源性;该调查海域表层沉积物重金属含量均符合第一类海洋沉积物质量标准,沉积物重金属对海洋生态系统仅存在轻微生态风险。 |
关键词: 海洋化学 重金属 海水 表层沉积物 生态风险 七连屿 |
DOI:10.3969/J.ISSN.2095-4972.2020.02.012 |
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基金项目:国家海洋局南海分局局长基金资助项目(1665);海南省自然科学基金资助项目(419QN381) |
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Environmental quality assessment of heavy metals in the surface water and sediments around Qilianyu Island |
HE Shi-chang,YU Guang-xin,WANG De-hong,CHEN Hai-nan,CHEN Qiao-di |
(Sansha Marine Environmental Monitoring Central Station, SOA, Haikou 570311, China;Fujian Institute of Oceanography, Xiamen 361013, China;Haikou Marine Environmental Monitoring Central Station, SOA, Haikou 570311, China) |
Abstract: |
In order to assess the marine environmental quality around Qilianyu Island in the South China Sea, 22 surface seawater samples and 6 surface sediment samples were collected in August 2017. The contents of heavy metals including Cu, Pb, Zn, Cd, Cr, As and Hg were determined by atomic absorption spectrophotometer and atomic fluorescence spectrophotometer. The levels of heavy metal pollution in surface seawater were evaluated by single factor method, comprehensive pollution index and correlation coefficient. The pollution levels and the potential ecological risk of heavy metals in sediments were evaluated by the single factor method and Hankanson potential ecological risk index. The results showed that the concentrations of heavy metals in surface seawater were in sequence of CZn>CPb>CAs>CCr>CCu>CCd>CHg. The Pb quality in seawater of some stations was no better than the first grade by the national standard of seawater quality, but by the comprehensive pollution index it was less than 1, which means that the surface seawater quality around Qilianyu Island could be taken as clean. Statistically significant negative correlations existed between ZnAs and CrCd in surface seawater, which suggested that these two groups of elements were from different sources. The contents of heavy metals in surface sediments conformed to the first grade by the national standard of marine sediment quality. The potential ecological risk index for heavy metals in this area was low accordingly. |
Key words: marine chemistry heavy metal seawater surface sediments ecological risk Qilianyu Island |