太湖沉积物重金属的形态特征及生态风险评价  

The distribution characteristics and evaluation of ecological risk of heavy metals in the surface sediment of Taihu Lake

作　　者：王沛芳[1,2] 周文明[1,2] 王超[1,2] 钱进[1,2] 侯俊[1,2] 郑莎莎[1,2] 

机构地区：[1]河海大学浅水湖泊综合治理与资源开发教育部重点实验室,南京210098 [2]河海大学环境学院,南京210098

出　　处：《重庆大学学报（自然科学版）》2012年第11期136-143,共8页Journal of Chongqing University

基　　金：国家自然科学基金重点资助项目(50830304);国家基础研究'973'课题资助项目(2008CB418203);江苏省自然科学基金重点资助项目(BK2010076)

摘　　要：对太湖29个点位表层沉积物中主要的重金属Cd、Pb、Cu、Cr含量及分布特征进行了研究,采用BCR提取法分析各种重金属赋存形态,并依据各种重金属的形态特征进行了生态风险评价。结果表明:表层沉积物中Cr含量最高,Cd最低;各湖区各种重金属含量分布不同,梅梁湾、竺山湾和贡湖湾的Cu和Cr含量较高,南部沿岸区Cu含量最低,湖心区Cr含量最低;各种重金属的赋存形态中,Cd可提取态所占比例最高,而Pb、Cu和Cr均以残渣态为主,表明Cd的迁移性最强。运用次生相与原生相比值法(RSP)对重金属潜在生态风险进行评价,发现Pb、Cu和Cr在全太湖处于无污染水平,而Cd在竺山湾和西部沿岸区入湖河口处于中度污染水平,在东太湖、胥湖湾、贡湖湾部分采样点处于轻度污染水平,说明Cd污染分布较广且污染较重,四种重金属的潜在生态风险由大到小的顺序为:Cd>Pb>Cu>Cr;从湖区平均值分析,南部沿岸区、湖心区和贡湖湾处于无污染水平,其它湖区处于轻度污染水平。但贡湖湾已接近轻污染水平。Research on the contents of heavy metals,such as Cd,Pb,Cu,Cr and their distribution characteristics in the surface sediments of 29 sampling sites in Taihu Lake,are conducted.Meanwhile,the distribution characters of the specific chemical forms of these heavy metals are analyzed with the method of BCR.Results show that the content of Cr has the highest values,while Cd has the lowest values,and contents of the four metals are different in different parts of Taihu Lake.The content of Cu and Cr in Meiliang Bay,Zhushan Bay and Gonghu Bay is high;while,the content of Cu in southern coast of the lake is the lowest;and the middle lake has the lowest content of Cr.Among the specific chemical forms of these heavy metals,the proportion of the extractable form of Cd is the highest,and Pb,Cu and Cr mainly exist in the residual form.This suggests Cd has the highest mobility among the four kinds of heavy metals.Furthermore,the potential ecological risk of these four kinds of heavy metals is evaluated by using the ratio of minor phase and progenetic phase（RSP）.It shows that Pb,Cu and Cr are at pollution-free level in all parts of the lake.However,Cd is at moderate-polluted level in the sampling sites of river inlets of Zhushang Bay and western coastal lake,and at light-polluted level in parts of sites of Eastern Taihu Lake,Xuhu Bay,and Gonghu Bay.It indicates that Cd is the more serious pollutant in the whole lake of Taihu.And the descending order of the potential ecological risks of these heavy metals is CdPbCuCr.Meanwhile,in terms of the different parts of the lake,southern coastal,middle lake and Gonghu Bay are at non-polluted level,and the others are at light-polluted level.However,the pollution level of Gonghu Bay is close to light-polluted level.

关 键 词：沉积物 重金属 形态 分布 生态风险 太湖 

分 类 号：X524[环境科学与工程—环境工程]