资源描述：
《渤海湾表层沉积物重金属在不同粒级有机_矿质复合体中的分布_刘俐》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、环境科学研究第19卷第1期ResearchofEnvironmentalSciencesVol.19,No.1,2006渤海湾表层沉积物重金属在不同粒级有机-矿质复合体中的分布1,2,314123刘俐,宋存义,熊代群,高新华,李发生(11北京科技大学土木与环境工程学院,北京100083;21中国环境科学研究院,北京100012;31桂林电子工业学院电子工程系,广西桂林541004;41华南热带农业大学农学院,海南儋州571737)摘要:采用超声分散法分离沉积物中不同粒级有机-矿质复合体,研究了渤海湾沉积物中Pb,Cd,C
2、r等重金属的污染及其在不同粒级有机-矿质复合体中的分布.结果表明,3种重金属含量总体上随着复合体粒径增大而减小.X射线衍射(XRD)结果显示,随着沉积物粒径的增大,主要来自原生矿物的石英和长石等岩石结构物质的含量增加,但这些物质中的重金属含量较低.渤海湾表层沉积物中重金属污染主要发生在以次生硅酸盐矿物及硅、铁、铝等氧化物或氢氧化物为主的细粒沉积物上,细粒样品由于其较大的比表面积和富含有机质的特性,通过吸附、沉淀、离子交换等,导致所含重金属含量较高.粘粒复合体中Pb含量是粗砂中的213倍,Cd是粗砂的318倍,而Cr是粗砂
3、的218倍.关键词:渤海湾;表层沉积物;粒级;有机-矿质复合体;重金属中图分类号:X524文献标识码:A文章编号:1001-6929(2006)01-0075-05DistributionofHeavyMetalsinDifferentFractionsofOrgano2MineralAggregatesinSurficialSedimentofBohaiBay1,2,31412LIULi,SONGCun2yi,XIONGDai2qun,GAOXin2hua,LIFa2sheng(1.CollegeofCivilandE
4、nvironmentalEngineering,UniversityofScience&TechnologyBeijing,Beijing100083,China;2.ChineseResearchAcademyofEnvironmentalSciences,Beijing100012;3.DepartmentofElectronicEngineering,GuilinUniversityofElectronicTechnology,Guilin541004,China;4.CollegeofAgronomy,South
5、ChinaUniversityofTropicalAgriculture,Danzhou571737,China)Abstract:Basedontheorgano2mineralaggregatesinvariousfractionsfromsurficialsedimentsbyultrasonicdispersioninwaterfollowedbysedimentation,thedistributionofheavymetalsPb,CdandCrintheorgano2mineralaggregatesoft
6、hesedimenthasbeeninvestigated.Itisshownthattheamountsofthethreemetalsgenerallydecreasewiththeincreaseofgrainsizesofsediment.TheXraydiffraction(XRD)analysisshowsthattheamountofquartzandfeldsparincreaseswhenthegrainsizeofsedimentincreases,andtheheavymetalsremainina
7、relativelylowlevel,whichmainlycomesfromtheprimarymineral.ItisindicatedthattheheavymetalsinsurficialsedimentsofBohaiBaymainlyexistinsecondarysilicatemineralandfinefractiondeposits,whichprimarilyconsistofoxideorhydroxideofSi,FeandAl.Thefinefractionsampleshaverelati
8、velylargespecificareasandrichorganicmattercontent,whichresultsinhighlevelsofheavymetalsthroughadsorption,depositionandionexchangeactivities.ThelevelsofPb,Cdand
