防城港海域沉积物重金属分布特征及风险评价

为探究防城港海域沉积物重金属污染水平，于2021年9月在防城港海域采集表层沉积物21件、柱状沉积物1件，对重金属和有机质的时空分布特征、相关性以及污染程度进行分析，并对重金属生态风险进行评价，分析重金属的来源。结果表明，防城港海域表层沉积物中Cu、Pb、Zn、Cr、Cd、As和Hg含量的平均值分别为18.78、34.86、78.90、61.55、0.06、9.27、0.05 mg·kg^-1,7种重金属含量均符合国家海洋沉积物一类标准。通过C/N值对柱状沉积物中有机质来源进行分析，结果表明研究海域重金属沉积过程中有机质来源以陆源有机质为主。相关性分析和聚类分析结果表明，研究海域表层沉积物中重金属的组成和分布主要受地质背景、近岸工业及人类活动的影响，其次为船舶和海水养殖等。地累积指数评价结果表明，存在轻微及以上污染的元素主要为Pb和Hg。潜在生态风险评价结果显示，重金属的潜在生态风险为Hg>Cd>As>Pb>Cu>Cr>Zn,潜在生态风险指数相对高值区分布在白龙半岛和企沙半岛南部，Hg是主要的潜在生态风险贡献因子。研究海域沉积物重金...

Distribution Characteristics and Risk Assessment of Heavy Metals in Sediments of Fangchenggang Sea Area

In order to explore the pollution level of heavy metals in the sediments of Fangchenggang sea area,21 surface sediments and 1 columnar sediment were collected in September 2021.The spatial and temporal distribution characteristics,correlation and pollution degree of heavy metals and organic matter were analyzed.The ecological risk of heavy metals was evaluated and the sources of heavy metals were analyzed.The results show that the average contents of Cu,Pb,Zn,Cr,Cd,As and Hg in the surface sediments of Fangchenggang sea area are 18.78,34.86,78.90,61.55,0.06,9.27 and 0.05 mg·kg^-1,respectively.The contents of 7 kinds of heavy metals all meet the first-class standard of national marine sediments.The source of organic matter in core sediments was analyzed by C/N value.The results showed that the source of organic matter in the heavy metals sedimentary process of the study area was mainly terrestrial organic matter.The results of correlation analysis and cluster analysis showed that the composition and distribution of heavy metals in the surface sediments of the study area were mainly affected by geological background,offshore industry and human activities,followed by ships and marine aquaculture.The results of geo-accumulation index evaluation showed that the elements with slight and above pollution were mainly Pb and Hg.The results of potential ecological risk assessment showed that the potential ecological risk of heavy metals was Hg>Cd>As>Pb>Cu>Cr>Zn.The relatively high value areas of potential ecological risk index were distributed in the Bailong Peninsula and the southern part of Qisha Peninsula,and Hg was the main potential ecological risk contribution factor.The biological toxicity risk of heavy metals in sediments of the study area is low.The study results can provide scientific basis for the sustainable development,marine environment protection and management of Fangchenggang sea area.