Hg同位素地球化学完整课件PPT格式课件下载.pptx
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80AtomicMass:
200.59amuMeltingPoint:
-38.87C(234.28K)BoilingPoint:
356.58C(629.73K)NumberofProtons/Electrons:
80NumberofNeutrons:
121Classification:
TransitionMetalCrystalStructure:
Rhombohedral(斜方六面体)Density293K:
13.456g/cm3Color:
Silver,Isotopegeochemistryofmercury,Mercuryandmercuryisotopes,Hgisachalcophileelement,Mercuryisatraceelement.,Mercurymineralbelt,NaturalcomponentofearthscrustintheformofCinnabar(HgS)Rytuba2003,Environ.Geol,1汞是毒性最强的重金属之一,无机汞毒性弱,甲基汞的毒性最强高神经毒性心血管毒性生殖毒性免疫系统效应肾脏毒性,无机汞,无机汞,汞污染的危害具有隐Hg2蔽+性MeH和g突发性,一旦发生重大污染事件或出现人群病变,将产生灾难性后果。
Chisso公司,1932年日本Chisso公司在水俣市建厂,1956年出现了震惊世界的水俣病事件1968年日本政府正式承认水俣病是当地居民食用甲基汞污染的海产品引起的2001年3月,日本官方确认水俣病患者2955人,死亡,1784人,但仍有10072人出,水现俣水俣病病是的世症界状而上未迄得今到为官止最严重的环境公方害确认事件,其深刻性和持久性史无前例。
孕妇低剂量长期甲基汞暴露会严重影响胎儿智力发育,母体发汞含量每增加1ppm,胎儿智商(IQ)平均下降约0.18美国每年有316,500-637,200名新生儿受到影响每年给美国带来约87亿美元的经济损失,2甲基汞有生物富集和生物放大作用,(USEPA,2011),因此环境中少量的汞污染,会造成食物链甲基汞,的显著富集。
3汞是全球性污染物长距离传输,汞是唯一在大气中主要以气态单质汞形式存在的重金属大气居留时间可达1年,Hg0,(Muntheetal.,2007;
USEPA,2011),北欧,美国不同流域鱼体汞的平均含量,人为活动排放的汞,在大气经长距离迁移后的沉降梭是造成这类鱼体汞污染主要原因,人子们认识到汞是一种全球性污染,这是鱼国际控制汞排放的直接,动因。
政府间谈判委员会系列会议,2013年达成国际汞公约,第一届,2010.6瑞典斯德哥尔摩,第三届,2011.10内罗毕,第五届,2013.10日本水俣市,旨在控制和削减全球人为汞排放和含汞产品的使用汞是国际关注的全球污染物,全面认识汞的大尺度迁移规律一直是国际学术界和政府管理部门关注的焦点,2000-2950,300-600,1700-2800,2000-2400,生物质土壤与植人为源排燃烧被释放放,地质成因的排放,80-600,沉降到陆地与河流,1500-3200,沉降到海洋,3700,河流380,颗粒物去除,垂直混合,221000,802000,200600腐殖层土壤,矿质层土壤,2900表层海洋134500,中间层海洋埋藏,深层海洋,海洋排放,大气,5000,Hg0,HgII,hv,自由基,汞库单位:
吨;
通量单位:
吨/年,汞排放清单汞在大气中的迁移转化规律大气与地表间汞的相互作用人为源排放,Selin,2009,Globalburdenincreasedfromnaturalbackgroundbyaboutafactor3(air,soils,sediments,fish),Hghasanactiveredoxchemistry,HgMethylation,Challenge:
MercuryreflectsthecomplexitiesofoneofthemostinsidiouslyinterestingandscientificallychallengingbiogeochemicalcyclesattheEarthssurfaceIsotopes,Concentraons,MolecularHgspecies,MeHg,ResearchintoHgstableisotopebiogeochemistryisofferingnewinsightintothebehaviorofHg.,一、汞是国际关注的全球污染物二、汞同位素测定方法三、汞同位素分馏四、自然体系样品中汞同位素组成五、应用实例六、展望,报告内容,Element:
Mercury,200.59,HgMercury,7stableisotopesM-196toM-204,0.15,10.0,16.8,13.2,29.83023.1,6.85,0,10,20,Abundance(%),196,198199200201202204,Hgisotope,Massdifferenceof4%.Activeredoxchemistry.Hgisavolatile.,Conventions(MadisonICMGProundtable),1.Lightisotope(198Hg)inthedenominator:
ex.,199Hg/198Hg,202Hg/198Hg,Deltastandard:
NISTSRM3133(10,000ppmHgin10%HNO3)SecondaryliquidHgbasedreferencematerials(Hg2+insolution):
UM-Almaden:
202Hg=-0.54(JoelBlum,Univ.Michigan)CPRGF65A:
202Hg=-3.55CRPGRL24H202Hg=+2.48(JeanCarignan,CRPG),wherexxxis199Hg,200Hg,201Hg,202Hg,204Hg,Conventions(MadisonICMGProundtable),1.Lightisotope(198Hg)inthedenominator:
202Hg=-3.55CRPGRL24H202Hg=+2.48(JeanCarignan,CRPG),Massdependentfractionation,XXX:
202,201,200,199199Hgmeasured=202Hgmeasured0.252200Hgmeasured=202Hgmeasured0.502201Hgmeasured=202Hgmeasured0.752,Conventions(MadisonICMGProundtable),1.Lightisotope(198Hg)inthedenominator:
202Hg=-3.55CRPGRL24H202Hg=+2.48(JeanCarignan,CRPG),199Hg()=199Hg(0.2520202Hg),200Hg()=200Hg(0.5024202Hg),201Hg()=201Hg(0.7520202Hg),Massindependentfractionation,Hgisotopicmeasurementsahistoricperspective,1919F.W.Aston:
discoveryofHgisotopes1920Brnsted:
fractionation/separationofHgisotopesbyliquidHgpycnometry1922Brnsted:
pycnometryofdifferentliquidHgsources,today,1935-1999Nier,Haeffner(gassourceMS).Kumar,Goel,Jovanovich(NAA):
anomalousHgisotopesinmeteorites,20091steverICMGPsessiononstableHgisotopes,2000-2001KlaueB,BlumJDEvansRD,HintelmannH,JacksonTAQ-ICP-MS,single-collectorICP/MS,ICP-TOF-MS.2000J.D.BlumHgColdvaporgeneration+MultipleCollectorICP-MS2001Laurettaetal.,GCAHgisotopesinMeteoritesbyCV-MC-ICPMS2003Hintelmann&
LuHgisotopicvariationsincinnabar(HgS)2006MassindependentHgisotopesfractionation(MIF)infish,MultipleCollectorInductivelyCoupledPlasmaMassSpectrometry,variablemulticollector,magnet,ESA,plasma,IonTransmissionHg2+(aq)2in100,000Hg0(g)200in100,000,ImagebyThermo,MultipleCollectorInductivelyCoupledPlasmaMassSpectrometry,Nu-instrument,MC-ICP-MSoffersthesimultaneousdetectionofmultipleisotopes.MC-ICP-MScombinesthemulti-detectorswithveryhighionizationefficiencyoftheICPsource,allowingveryhighprecisionisotopicanalysisforvariousele