辽东湾表层沉积物的重金属污染特征与质量评价

Pollution characteristics and quality assessment of heavy metals in surface sediments from the Liaodong Bay

本文研究了辽东湾表层沉积物中重金属的分布及污染特征,评价其生态风险及环境质量。对辽东湾表层沉积物8种重金属(As、Cu、Cd、Cr、Hg、Ni、Pb、Zn)的空间分布进行了研究,采用Hankanson法和Igeo(地累积指数)分析了该海域重金属潜在生态风险,并评价了该海域的环境质量。在辽东湾葫芦岛附近海域、西南部六股河口东南部海域以及西部近岸海域表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb和Zn含量偏高。地累积指数法及生态风险指数法对重金属污染程度评价结果一致,辽东湾生态环境具有潜在危害的重金属主要是Cd、Hg和As,8种重金属潜在生态风险系数由高到低依次为Cd、Hg、Cu、Pb、As、Zn、Ni和Cr,各站位重金属综合潜在生态风险指数均大于150,生态风险总体上处于中等生态风险等级。Cd和Hg是该海域沉积物重金属中主要污染物,局部区域达到中、中-强污染程度。环境质量评价表明,辽东湾表层沉积物重金属引发有害生物效应的可能性不大,但Cd和Hg显著富集,应予以重视。

The present study analyzed the distribution and pollution characteristic of heavy metals in surface sediments from the Liaodong Bay,and then evaluated the potential ecological risk caused by heavy metals to learn the environment quality of sediments.Content distributions of heavy metals including As,Cu,Cd,Cr,Hg,Ni,Pb and Zn in surface sediments from the Liaodong Bay were studied.Simultaneously,the potential ecological risks of these heavy metals were analyzed by the index method on potential ecological risk and geoaccumulation index（Igeo）and Environment quality in surface sediments from the Liaodong Bay was evaluated.The contents of As,Cu,Cd,Cr,Hg,Ni,Pb and Zn in surface sediments appeared higher near the Huludao,southeast sea of the Liugu estuary in the southwest part,near sea in the western.The results of pollution assessment by index of geoaccumulation and the potential ecological risk index were almost the same.The order of ecological risk of these heavy metal is as follow：Cd〉Hg〉Cu〉Pb〉As〉Zn〉Ni〉Cr,with Cd,Hg and As being the potential risk elements for the ecological environment from the Liaodong Bay.The assessment result of ecological risk revealed this area belongs to moderate potential ecological risk.The environmental quality assessment showed that the heavy metals in surface sediments from the Liaodong Bay were not likely to cause harmful biological effects,but Cd and Hg were significantly enriched,therefore much attention should be paid to these areas.