环境概论.docx

环境概论.docx

《环境概论.docx》由会员分享，可在线阅读，更多相关《环境概论.docx（11页珍藏版）》请在冰豆网上搜索。

环境概论

重点

一．Classifyingenvironmentalproblems环境问题分类

1.Overpopulation人口过剩

2.Pollution污染

3.Depletionofresources资源消耗殆尽

4.Changesintheglobalcondition全球环境的改变

二．Pollution污染

1.Matterorenergy物质或能量

2.Negativelyaffectsenvironmentorhumanwellbeing

三．Basicprinciple

1.Matterandenergyareindestructible不能破坏的

2.Thereforepollutionisindestructible!

四．Pollutioncontrolmethods

1.Recovery恢复

2.Wasteminimization最小化

3.Conversion转变

4.Storage

Recovery

•Recycle:

usewastesassourceofrawmaterials原材料

•Reuse:

usematerials原料morethanonce

Wasteminimization

•Changeproduct改变产物

•Alterprocess

Conversion转变

•Transformpollutantstoharmlessorusefulmaterials:

把污染物变成·轻污染或无污染的原料

•OxidizeCOtoCO2

•Convertwastestocompost

Storage

Ensurethatthepollutantswillnotmigrateout迁移

Ensurethatpollutantswillnotreactwitheachother

Asustainable长期的development

1EnvironmentalScientistsand2Engineers

1.Evaluatesourceandnatureofpollutionproblem对资源和污染物的性质进行评价

Evaluateenvironmentalimpact评估环境污染的影响

2.Evaluatepossiblesolutions

Design,buildandoperatepollutioncontrolsystems.评估可行的解决方法，建造并实行污染控制系统

Outline

Problems

Unevenwaterresources

•Watershortage

•Flooding

Waterpollution

•Eutrophication

•RiverRehabilitant

•WaterandWastewaterTreatment

3333333333333333333333333333

Stepsforthestudyofwaterandwastewatertreatment

Waterproperty特性

Treatmentmethods

Watertreatment

Wastewatertreatment

1Primarytreatment初级处理

2Secondarytreatment第二步处理

3Tertiarytreatment第三步处理

4Sludgetreatment污泥处理

Physicalwater-quatyparameters:

definethosecharacteristicsofwaterthatrespondtothesensesofsight,touchorsmell

Suspendedsolids固体悬浮物

Turbidity浑浊

Temperature

Conductivity导电性

Color

Tasteandodor

Suspendedsolidsaretypically主要comprised组成ofclay粘土,silt淤泥,fineparticulateorganic细小的有机物质andinorganicmatter无机物质andmicroscopicorganisms.微生物的有机体

Thesuspendedsolidsparameter参数isusedtomeasurethequalityofthewastewaterinfluent,tomonitor检测severaltreatmentprocesses,andtomeasurethequalityoftheeffluent.

Insuspension在悬浮液中,solidsincreaseturbidity,andthereducedlightpenetration减少光的穿透性mayrestrictthephotosyntheticactivityofplants,会限制植物的光合作用inhibitthevisionofaquaticanimals阻碍了水生动物的视力,interfere干扰withfeedingofaquaticanimalsthatobtainfoodbyfiltration干扰水生动物通过过滤进食,andbeabrasivetorespiratorystructuressuchasgills鱼鳃offish.

Formosttreatedwastewater,amaximumsuspendedsolidsstandardof30mg/Lwas最大固体悬浊物指标为30mg每升setbyEPA.

Turbidity

Turbidityisameasureoftherelativeclarityofwater水的相对清晰度:

thegreatertheturbidity,themurkierthewater.浊度越大水越黑Turbidityincreasesasaresultofsuspendedsolidsinthewaterthatreducethetransmissionoflight浊度的提高是由水中的悬浊物引起的.Sothewaterisdirty,what'sthebigdeal?

Withhigherlevelsofturbidity,waterlosesitsabilitytosupportadiversityofaquaticorganisms.水失去了自身的对有机物的控制力

Waterbecomeswarmerassuspendedparticlesabsorbheatfromthesunlightandcauseoxygenlevelstofall.水温升高是由于固体物质吸收阳光引起的Remember-warmwaterholdslessoxygenthancoolerwater!

热的水含氧量比水底

Photosynthesisdecreasesbecauselesslightpenetratesthewater,resultinginevenfurtherdropsinoxygenlevels.

Thecombinationofwarmerwater,lesslightandoxygendepletionmakesitimpossibleforsomeformsofaquaticlifetosurvive.

Temperature

Theratesofbiologicalandchemicalprocessesdependontemperature化学反应的速率靠温度.

Temperatureaffectstheoxygencontentofwater（oxygenlevelsbecomelowerastemperatureincreases）温度升高影响氧在水中的含量，温度越高水含量越低;therateofphotosynthesisbyaquatic水生的plants影响水生植物的光合作用速率;themetabolism新陈代谢ratesofaquaticorganisms生物;影响水生生物的新陈代谢andthesensitivityoforganismstotoxic有毒的wastes,parasites寄生物,anddiseases.和对有毒污染物、寄生虫、和疾病的敏感度

Thermalpollutionisawaythatthetemperatureofwatercanincrease.Thermalpollutionisanincreaseinwatertemperaturecausedbyaddingrelativelywarmwatertoabodyofwater.热污染是一种水的温度提升的污染，由于往水中排放温暖的水

Thermalpollutioncancomefromstormwaterrunningoffwarmedurbansurfaces（streets,sidewalks,parkinglots）andindustriesthatdischargewarmwaterfromtheirfacilitiesthatwasusedtocoolmachinery.热污染来是自城市流出的水或是工厂由于用于冷却设备后而排除的水

Chemicalwater-qualityparameters因素

pH

Alkalinity碱度

DO需氧量

Totaldissolvedsolids总共溶解的固体

Metals重金属

Hardness硬度

Organics（BOD,COD）有机物含量，化学需氧量和生物需氧量

Nutrients营养物质

pHpHisthepercentageofhydrogenions（H+）inasolution.氢离子的百分率在溶液中的Asolutionismoreacidicwhenitcontainsmorehydrogenions.溶液呈酸性当含有更多的氢离子时Thelevelofaciditycanbechangedbyhuman’sactions.酸性可以被人类的行为改变Acidrain,aresultofairpollution酸雨是空气污染的结果andmatteremittedfromtailpipes废气从排气尾管中排除andsmokestacksaffectthepH烟的航向影响ph值.ApHof7isconsideredtobeneutral。

ph为7认为是中型的.WhenthepHislessthan7,itisacidic;apHgreaterthan7isbasic.ApHvaluebetween7.0and8.0areoptimalforsupportingadiversaquaticecosystem.ph值在7-8是水生系统的最佳状态

Alkalinity什么是碱度？

Alkalinityisatotalmeasureofthecapacityofwatertoneutralizeacids碱度是对水体酸性进行中和的总体测量

.AlkalinityisnotapollutantandisdifferentfrompH.pHmeasuresthestrengthofanacidorbase.ph测量一个酸性物质的酸度Alkalinityindicatesasolution'spowertoreactwithacidandbufferitspH碱度指示一个中和酸性和缓冲溶液ph的解决能力,thepowertokeepitspHfromchanging.一种阻止ph改变的能力

AlkalinityisimportantforfishandaquaticlifebecauseitprotectsorbuffersagainstpHchanges碱度对水生生物非常重要，因为他可以保护或缓冲溶液的ph不发生改变（keepsthepHfairlyconstant不变的）andmakeswaterlessvulnerabletoacidrain.使得水体对酸雨不是很敏感Themainsourcesofnaturalalkalinityarerocks碱的主要来源是岩石,whichcontaincarbonate,bicarbonateandhydroxidecompounds.钙盐、重碳酸盐，和氢氧化物

Alkalinecompoundsinthewatersuchasbicarbonates（bakingsodaisonetype）,carbonates,andhydroxidesremoveH+ionsandlowertheacidityofthewater（whichmeansincreasedpH）.这些东西都和H离子反应

DissolvedOxygen（DO）

Aquaticlifeusesoxygenthatisdissolvedinthewaterandisinmuchsmallerquantitiesthanintheair.Oxygen,inwater,ismeasuredasdissolvedoxygen（DO）.Ifmoreoxygenisconsumedthanisproduced,dissolvedoxygenlevelsdeclineandsomesensitiveanimalsmaymoveaway,weaken,ordie.

Weather,temperatureandsalinity盐分affectamountsofdissolvedoxygen（DO）.Cold,freshwaterholdsmoreoxygenthanwarmorsaltywater冷水淡水含有氧的量比热的咸的水高.IfDOlevelsareseverely严重缺乏low,largequantitiesoffishmaydie.

Thestreamsystemgainsoxygenfromtheatmosphereandfromaquaticplantsasaresultofphotosynthesis河流从大气或进行光合作用的水生植物那里获得氧气.Runningwater,becauseofitschurning,dissolvesmoreoxygenthanstillwater流动的水由于搅拌比净水获得的氧更多.Respirationbyaquaticanimals,decomposition,andvariousotherchemicalreactionsconsumeoxygen.水生动物，微生物的分解作用和其他的一些化学反应都需要消耗氧气

Totaldissolvedsolidsistheamountofparticlesthataredissolvedinthewater.溶解的颗粒物

Dissolvedsolidsmaycomefromorganicsourcessuchasleaves,silt,plankton,andindustrialwasteandsewage.可能的来源为树叶、於泥、浮游生物，工业废物和废水

Changesintheamountsofdissolvedsolidscanbeharmfulbecausethedensityoftotaldissolvedsolidsdeterminestheflowofwaterinandoutofanorganism’scells溶解物的浓度的变化是有害的，因为溶解物的浓度决定水在有机体内的进出.Manyofthesedissolvedsolidscontainchemicals,suchasnitrogen,phosphorous,andsulfur,whicharethebuildingblocksofmoleculesforlife溶解物中含有生物必须的化学成份N、p、s等.

DrinkingwatermayhaveaTDSreadingof25-250mg/L.DistilledwaterwillhaveaTDSreadingthatwillrangefrom0.5-1.5mg/L.TheamountofTDSrangesfrom100-20,000mg/Linriversandmaybehigheringroundwater.Seawatermaycontain35,00mg/LofTDS.LakesandstreamsmayhaveaTDSreadingof50-250mg/L.不同的水体好友tds的量不同

Heavymetalpollutionistypically典型的，特有的associatedwithminingactivitiesordischargesfromsomeindustries.重金属污染和采矿活动相联系的一种特有的污染，或者由工业生产而排放

Persistenttoxicants（heavymetals）inwaterandsediments沉淀物affectedbyheavymetalpollutioncanhaveseriousaffectsontheaquaticecosystemandcanmakewaterunsuitableforhumanconsumption.不断的有水和沉淀物被重金属所影响并造成很严重的后果对水生生态系统而且使得水体不适合人类使用

Cumulativetoxins积累的毒素:

Arsenic砷,Cadmium镉,Chromium铬,Lead铅,Mercury.汞

Someanimalscanalso‘bioaccumulate’生物富集metals,makingthemunsafetoeat.使得他们不能被人类食用Theyareconcentratedbythefoodchain他们通过食物链被富集,therebyposingthegreatestdangertoorganismsnearthetopofthechain.因此受到最大危害的是最靠近链中最高级的生物

Hardness

Hardnessisdefinedastheconcentrationofmultivalentmetalliccationsinsolution.Atsupersaturated4conditions,thehardnesscationswillreactwithanionsinthewatertoformasolidprecipitate.

Themultivalentmetallicionsmostabundantinnaturalwatersarecalcium（Ca2+）andmagnesium（Mg2+）.Othersmayincludeironandmanganeseintheirreducedstates（Fe2+,Mn2+）.

Agenerallyacceptedclassificationisasfollows:

Soft<50mg/lasCaCO3

Moderatelyhard50-150mg/lasCaCO3

Hard150-300mg/lasCaCO3

Veryhard>300mg/lasCaCO3

ThePublicHeathServicestandardsrecommendamaximumof500mg/lofhardnessindrinkingwater.

BiochemicalOxygenDemand生物需氧量

Whenorganicmatterdecomposes,microorganisms（suchasbacteriaandfungi）feeduponthisdecayingmaterialandeventuallyitbecomesoxidized.有机物腐败后被微生物氧化分解成气体Biochemicaloxygendemand,orBOD,measurestheamountofoxygenconsumedbymicroorganismsintheprocessofdecomposingorganicmatterinstreamwater.

BODdirectlyaffectstheamountofdissolvedoxygeninriversandstreams.bod直接反应水体中的溶解氧的量Themorerapidlyoxygenisdepletedinthestream,thegreatertheBOD.Thismeanslessoxygenisavailable.

SourcesofBODincludeleavesandwoodydebris残骸;deadplantsandanimals;animalmanure粪便;effluentsfrompulpandpapermills工厂,wastewatertreatmentplants,feedlots,andfood-processingplants;fallingsepticsyste