《保护臭氧层》ppt课件

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1、保護臭氧層OZONELAYERPROTECTION臭氣層OZONELAYER在離地面15至35公里的平流層內，由臭氧氣體形成的一道屏障Ashieldofozonegasinthestratospherebetween15to35km它能吸收紫外光的輻射，因此可阻擋來自太陽有害光線的滲透Itabsorbsultraviolet(UV)radiation,thusinhibitingpenetrationofharmfulUVraysfromthesun一九七五年，科學家己測到每年春季，南極洲上空豐厚的臭氧層呈現急劇轉薄的現象In1975,scientistsha

2、vedetectedaseveredropinozoneabundanceinthelayeroverAntarcticaeachspring臭氣層OZONELAYER一九八七年，發現南極洲上空的臭氧層消失了一半，出現一個大缺口，面積相等於美國總面積的兩倍In1987,halfofAntarctica’sozonewasfoundtohavedisappearedoveraregiontwicethesizeofUS,creatinganenormous“hole”intheozonelayer當地球表面受到更多紫外光的輻射時：WithmoreUVradiat

3、ionreachingtheearth’ssurface:皮膚癌、白內障等發病率增加，人體免疫系統受損Increasedincidenceofskincancer,eyecataracts,damagetohumanimmunesystem地球生態系統受破壞Damagetotheecologyoftheearth臭氧層的損耗，乃由損耗臭氧層的物質所造成Ozonedepletioniscausedbytheozonedepletingsubstances消耗臭氧層物質OzoneDepletingSubstances消耗臭氧層的物質OZONEDEPLETINGSU

4、BSTANCES(ODSs)是人造化學化合物-鹵烴、其中包括碳和鹵素(氟、氯或溴)原子Afamilyofman-madechemicalcompounds-halocarbons,containingcarbonandhalogen(Fluorine,ChlorineorBromine)atomsODSs性質極其穩定，延續長久，存在於大氣下層，可飄浮至離地面16公里的平流層Extremelystableandalonglifespanintheloweratmosphereallowingtransporttothestratospheresituated16

5、kmabovethegroundlevel在平流層內ODSs遭紫外光作用而分解，釋出氯原子與臭氧作用而產生氧分子，因而降低平流層內臭氧濃度Inthestratosphere,ODSsarebrokendownbytheactionofultravioletlight,releasingchlorineatoms,reactingwithozonetoproducemolecularoxygen,thusreducingtheozoneconcentrationofthestratosphericozonelayer.消耗臭氧層物質包括ODSsinclude含氯

6、氟氫ChloroFluoroCarbons(CFC)鹵代碳氫化合物(哈龍)HALogenatedhydrocarbON(HALON)甲基氯仿(1,1,1-三氯乙烷)MethylChloroform(1,1,1-trichloroethane)甲基溴MethylBromide四氯化碳(四氯甲烷)Carbontetrachloride(Tetrachloromethane)含溴氟氫HydroBromoFluoroCarbons(HBFC)含氯氟氫HydroChloroFluoroCarbons(HCFC)消耗臭氧層的物質OZONEDEPLETINGSUBSTANC

7、ES(ODSs)消耗臭氧層物質的用途ApplicationofOzoneDepletingSubstances消耗臭氧層物質的用途APPLICATIONOFODSCFC,HCFC：供冷氣工程和製冷工業用作冷卻劑(CFC-11,CFC-12andHCFC-22)Usedasrefrigerantsintheair-conditioningandrefrigerationindustry作為噴霧劑的推進劑(CFC-11andCFC-12)Usedaspropellantsforaerosolsprays供發泡膠工業用作發泡劑(CFC-11andCFC-12)Use

8、dasblowingagentsfor