化学化工专业英语试题_化学工程与工艺专业英语阅读教程_化学工程与工艺考教师(56)

Duringthepast20years,publicattentionhasbeenfocusedonwaysthatmankindhascausedchangesintheatmosphere:acidrain,stratosphericzonedepletion,greenhousewarming,andtheincreasedoxidizingcapacityoftheatmosphere.Wehaveknownforgenerationsthathumanactivityhasaffectedthenearbysurroundings,butonlygraduallyhavewenoticedsucheffectsasacidrainonaregionalthenonanintercontinentalscale.Withtheproblemofozonedepletionandconcernsaboutglobalwarming,wehavenowtrulyenteredaneraofglobalchange,buttheunderlyingscientificfactshavenotyetbeenfullyestablished.

在过去的二十年中，公众的注意力集中在人类对大气层的改变：酸雨、平流层臭氧空洞、温室现象，以及大气的氧化能力增强，前几代人已经知道，人类的活动会对邻近的环境造成影响，但意识到像酸雨这样的效应将由局部扩展到洲际范围则是慢慢发现的。随着臭氧空洞问题的出现，考虑到对全球的威胁，我们已真正进入到全球话改变的时代，但是基本的科学论据还没有完全建立。

LifeCycleAnalysis

Everystageofaproduct’slifecyclehasanenvironmentalimpact,startingwithextractionofrawmaterials,continuingthroughprocessing,manufacturing,andtransportation,andconcludingwithconsumptionanddisposalorrecovery。Technologyandchemicalsciencearechallengedateverystage。Redesigningproductsandprocessestominimizeenvironmentalimpactrequiresanewphilosophyofproductionandadifferentlevelofunderstandingofchemicaltransformations。Environmentallyfriendlyproductsrequirenovelmaterialsthatarereusable,recyclable,orbiodegradable;propertiesofthematerialsaredeterminedbythechemicalcompositionandstructure。

Tominimizewasteandpollutingby-products,newkindsofchemicalprocessschemeswillhavetobedeveloped。Improvedchemicalseparationtechniquesareneededtoenhanceefficiencyandtoremoveresidualpollutants,whichinturnwillrequirenewchemicaltreatmentmethodsinordertorenderthemharmless。Pollutantssuchasradioactiveelementsandtoxicheavymetalsthatcannotbereadilyconvertedintoharmlessmaterialswillneedtobeimmobilizedininertmaterialssothattheycanbesafelystored。Finally,theleftoverpollutionofanearlier,lessenvironmentallyawareerademandsimprovedchemicalandbiologicalremediationtechniques。