洞庭湖沉积物中重金属污染特征与评价.

J.LakeSci.(湖泊科学),2008,20(4):477-485http://www.jlakes.org.E-mail:jlakes@niglas.ac.cn©2008byJournalofLakeSciences洞庭湖沉积物中重金属污染特征与评价*祝云龙1,2,姜加虎1**,孙占东1,黄群1,王红娟1,2,周云凯1,2(1:中国科学院南京地理与湖泊研究所,南京210008)(2:中国科学院研究生院,北京100049)摘要:于2003-2004年在洞庭湖湖区采集沉积物样品700个,测定了沉积物中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量,并用地积累指数方法和主成分分析法对沉积物中的重金属污染状况进行了评价和分析.结果显示,洞庭湖各子湖区沉积物中Cd、Cr、Cu、Pb、Zn的平均含量都属于国家土壤二级标准,As、Hg、Ni属于国家土壤一级至二级土壤标准;在南洞庭湖与东洞庭湖入湖河流的三角洲的前缘是沉积物重金属积累最高的地点,而在西洞庭湖入湖河流三角洲的后缘沉积物重金属含量比前缘高.采用综合地积累指数法对洞庭湖各子湖区沉积物进行评价,结果表明:南洞庭湖(重污染)>东洞庭湖(偏重污染)>西洞庭湖(中度污染)>大通湖(中度污染)>城陵矶(轻度污染).采用主成分分析法对洞庭湖各子湖区沉积物进行分析,结果表明:南洞庭湖与东洞庭湖第一主成分贡献率分别为55.22%、56.86%,主要支配As、Cd、Hg、Pb、Zn的载荷,而第二主成分贡献率分别为30.04%、33.11%,主要支配Cu、Cr、Ni的载荷;西洞庭湖、大通湖和城陵矶因沉积物重金属来源不同,主成分分析结果相差较大.关键词:沉积物;重金属;污染评价;主成分分析;洞庭湖CharacterandassessmentofheavymetalsinthesedimentsfromLakeDongtingZHUYunlong1,2,JIANGJiahu1,SUNZhandong,HUANGQun1,WANGHongjuan1,2&ZHOUYunkai1,2(1:NanjingInstituteofGeographyandLimnology,ChineseAcademyofSciences,Nanjing210018,P.R.China)(2:GraduateSchoolofChineseAcademyofSciences,Beijing100049,P.R.China)Abstract:700sedimentsampleswerecollectedfromLakeDongtingduring2003-2004,andconcentrationsofAs,Cd,Cr,Cu,Hg,Ni,Pb,Zninthesedimentsweremeasuremed.TheresultsshowedthattheaverageconcentrationsofCd,Cr,Cu,Pb,ZndidnotexceedthestandardsofClassIIofenvironmentalqualitystandardforsoilsinChina;theaverageconcentrationsofAs,HgandNiwerebetweenthestandardsofClassIandthestandardsofClassIIofthestandard.TheheavymetalsineastLakeDongtingandsouthLakeDongtingweremostlyaccumulatedinthefrontofthedeltawhereriversranintothelake,howevertheheavymetalsinwestLakeDongtingweremostlyaccumulatedintherearpartofthedelta.ResultswithintegrativeindexofgeoaccumulationshowedthatthedecreasingorderofthedegreeofheavymetalpollutioninLakeDongtingwasasfollows:southLakeDongting>eastLakeDongting>westLakeDongting>LakeDatong>Chenglingji.Principalcomponentanalysis(PCA)wasappliedtostudytheheavymetalsinthesedimentsfromLakeDongting.Resultsshowedthatthefirstprincipalcomponent(PC1)insouthLakeDongtingaccountsfor55.2