海州湾北部沉积物重金属来源解析及污染评价

Sources Apportionment and Pollution Assessment of Heavy Metals in the Sediments of the Northern Haizhou Bay in China

基于海州湾北部海域15个采样站位表层沉积物7种重金属含量(As、Hg、Cu、Pb、Zn、Cr、Cd)测定,研究了重金属空间分布特征,采用主成分分析法解析重金属来源,应用地累积指数法和潜在生态风险指数法评价重金属污染程度和生态危害程度.结果表明:Cd、Pb、Zn、Cu和As 5种元素平均含量超过江苏海涂背景值,分别是背景值的2.62、2.58、1.80、1.35和1.24倍,存在明显的富集.研究区重金属来源以自然来源为主,Cr和Hg受自然来源控制;Zn、As、Cd和Cu主要来源于工业、农业和生活污染;Pb来源于船舶污染.地累积指数法评价结果显示,Pb和Cd地累积指数高于其他元素,为轻度—偏中度污染.潜在生态风险指数法评价结果显示,研究区总体处于低生态风险水平,Cd为主要风险元素,达到中—较高生态风险水平,其他元素均为低风险.

In this paper,concentrations of 7 heavy metals（As,Hg,Cu,Pb,Zn,Cr,Cd）in 15 surface sediments of the Northern Haizhou Bay were investigated to determine their spatial distribution,pollution and sources of heavy metals. The results indicated the mean contents of Cd,Pb,Zn,Cu and As were 2.62,2.58,1.80,1.35 and 1.24 times of their respec-tive background values of the coastal regions of Jiangsu Province,which indicated there were obvious accumulations of these heavy metals. A multivariate analysis（PCA）indicated that Cr and Hg were mainly from natural contributions,while Zn,As,Cd and Cu were influenced by industrial,agricultural and domestic pollution.Pb may be mainly derived from ship pollution. The geoaccumulation index for Haizhou Bay indicated a slight to moderate pollution by Pb and Cd. The overall ecological risk of study area was at low ecological risk level,Cd was the most important contaminating elemet with a middle-level to high-level ecologicl risk while other elements had low ecologicl risk level.