海河流域主要河口区域沉积物中重金属空间分异及生态风险评价  

Spatial Distribution and Ecological Risk Assessment of Heavy Metals in the Estuaries Surface Sediments from the Haihe River Basin

作　　者：吕书丛[1,2] 张洪[1] 单保庆[1] 李立青[2] 

机构地区：[1]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085 [2]中国地质大学环境学院,武汉430074

出　　处：《环境科学》2013年第11期4204-4210,共7页Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07203-006)

摘　　要：针对海河流域河流污染严重，河口区域污染状况以及陆源河流污染对河口区域影响不明确的问题，选取海河流域10个主要人海河口为研究对象，对其表层沉积物中Pb、Cu、Zn、Cd、Cr、Ni进行总量及空间分异性研究，采用潜在生态危害指数法进行重金属生态风险评价．结果表明，沉积物中6种重金属元素均有较明显的积累，含量高于海河流域主要土壤类型环境背景值，其中Cu、Ni、Pb达到环境背景值的2．3～2．6倍．重金属污染具有一定的空间分异性，Cu、Zn、Cr、Ni在永定新河、子牙新河、北排河3处的含量较高，4种元素相关系数为R_Cu-Zu=0．891、R_CU-Cr=0．927、R_Cu-Ni=0．964、R_Zn-Cr=0．842、R_Zn-Ni=0．939、R_Cr-Ni=0．879（P〈0．01），具有一定的同源性，并与流域内总人口显著相关，相关系数R分别为0．855、0．806、0．867和0．855（P〈0．01）．Ph、Cd的空间差异较小，含量范围分别为23．3-95．8mg·kg-1、0．051～0．200mg·kg-1，与其它元素及流域内总人口相关性不强，反映出河口区域的Cd和Pb与陆源污染关系不大．潜在生态危害指数评价显示，海河流域河口区域整体为轻微生态风险等级（RI为33．7～116），Cd为主要污染元素，在多数河口Cd均达到中等风险等级（E i r 为18．0-48．9）．It is well known that the rivers in the Haihe River Basin have been seriously polluted. However, what is the present condition of the estuary pollution and how the polluted inland rivers affect the estuary areas are not clear. 10 main estuaries of the Haihe River Basin were selected to measure the contents of typical heavy metals （Pb, Cu, Zn, Cd, Cr and Ni） in the surface sediments and to analyze the spatial distribution of these heavy metals. The potential ecological risk index was used to assess the ecological risk of the six heavy metals in the estuaries. The results showed that the contents of Pb, Cu, Zn, Cd, Cr and Ni in the surface sediments of the 10 estuaries were all higher than their background values in the main local soil types and the contents of Cu, Ni and Pb were 2.3-2. 6 times as high as their background values, which indicated that the estuaries were contaminated by the six heavy metals. The results also indicated that the contents of the six heavy metals in surface sediment varied from one estuary to another. The four heavy metals of Cr, Cu, Ni and Zn had bigger spatial differences than Pb and Cd in the contents in sediment from different estuaries. The contents of Cr, Cu, Ni and Zn in sediment were higher in the estuaries of the Yongdingxin River, Ziyaxin River and Beipai River than those in the other estuaries, and there were significant correlations between each other （R_Cu-Zn = 0. 891, R_Cu-Cr = 0. 927, R_Cu-Ni = 0. 964, R_Zn-Cr = 0. 842, R_Zn-Ni = 0. 939, and R_Cr-Ni = 0. 879, P 〈 0. 01 ） , which indicated that they possibly came from the same sources. Moreover, the contents of Cr, Cu, Ni and Zn in sediment also had significant correlations with the populations of sub-river basins with correlation coefficients of 0. 855, 0. 806, 0. 867 and 0. 855 （ P 〈 0. 01 ） , respectively. The contents of Cd and Pb had smaller spatial differences in sediment from different estuaries than the other heavy metals, with the values ranged 23.3-95.8 mg.kg-1 and 0. 051-0. 200 mg.kg-1. Contents o

关 键 词：海河流域 河口 表层沉积物 重金属 空间分异性 生态风险 

分 类 号：X522[环境科学与工程—环境工程]