广东省大亚湾和红海湾表层沉积物重金属分布特征及风险评价

Distribution and ecological risk assessment of heavy metal sediments in Daya Bay and Honghai Bay of Guangdong Province

2021年夏季采集了大亚湾和红海湾表层沉积物样品,分析了沉积物中铜(Cu)、砷(As)、铬(Cr)、镉(Cd)、汞(Hg)、铅(Pb)和锌(Zn)含量,探讨了重金属分布及污染特征,重金属之间及与总有机碳(TOC)的相关关系,并评价了重金属的总体污染状况和潜在生态风险.结果显示,大亚湾Hg、As、Cr、Cu、Zn、Cd和Pb含量平均值分别为0.03、8.71、59.8、14.2、99.4、0.05、33.4 mg·kg^(-1),红海湾Hg、As、Cr、Cu、Zn、Cd和Pb含量平均值分别为0.05、9.03、46.3、15.4、77.7、0.07、34.1 mg·kg^(-1).大亚湾Hg、As含量近岸低于远岸,Cr、Cu和Zn含量近岸高于远岸,Cd和Pb近岸和远岸相差不大.除重金属Cr之外,红海湾其他重金属含量近岸明显高于远岸.除Hg和Cr与TOC无显著相关性,沉积物中As、Cu、Zn、Cd和Pb与TOC呈显著正相关性.大亚湾和红海湾沉积物重金属,单因子污染影响程度依次为Cr>Zn>Pb>As>Cu>Pb>Cd,总体污染程度很低.基于总金属综合潜在风险评价,大亚湾和红海湾沉积物的风险较低,生态危害影响依次为,Hg>Cd>As>Pb>Cu>Zn>Cr.

In the summer of 2021,surface sediment samples were collected from Daya Bay and Honghai Bay.The concentrations of Cu,As,Cr,Cd,Hg,Pb and Zn in the sediments were analyzed to investigate the distribution and pollution characteristics of heavy metals.The relationships between the heavy metals and total organic carbon(TOC)were also examined,and an assessment of the overall pollution status and potential ecological hazards of the heavy metals was conducted.The results showed that the average concentrations of Hg,As,Cr,Cu,Zn,Cd,and Pb in Daya Bay sediments were 0.03,8.71,59.78,14.2,99.4,0.05,and 33.4 mg·kg^(-1),respectively.In Honghai Bay sediments,the average concentrations of Hg,As,Cr,Cu,Zn,Cd,and Pb were 0.05,9.03,46.29,15.4,77.7,0.07,and 34.1 mg·kg^(-1),respectively.The concentrations of Hg and As were lower near the coast than offshore in Daya Bay,while the concentrations of Cr,Cu,and Zn were higher near the coast than offshore.The difference in Cd and Pb concentrations between nearshore and offshore areas was not significant.In Honghai Bay,except for Cr,the concentrations of other heavy metals were significantly higher near the coast than offshore.Except for Hg and Cr,there was a significantly positive correlation between the concentrations of As,Cu,Zn,Cd,Pb,and TOC in the sediments.The single factor pollution degree of heavy metals in Daya Bay and Honghai Bay sediment was ranked as Cr>Zn>Pb>As>Cu>Pb>Cd,indicating a low pollution status.Based on the comprehensive potential risk assessment of total metals,the risks associated with the sediments in Daya Bay and Honghai Bay were low,with the ecological hazards ranked as Hg>Cd>As>Pb>Cu>Zn>Cr.