1、PART 2 ATMOSPHERIC CHEMISTRY AND AIR POLLUTION CONTROLUnit 8 Type and Sources of Air PollutantsGOD SAVE ME!O3:我快完了SO2 CO2:哈哈,你死定了u Background IntroductionAir Pollutants!vprimary pollutant 一次污染物一次污染物 vsecondary pollutant 二次污染物二次污染物 vair stagnation 空气流动停滞,大气停滞空气流动停滞,大气停滞 vherbicide 除草剂除草剂 vpesticide 杀
2、虫剂杀虫剂/农药农药 v正常浓度正常浓度 normal concentration v严重污染的严重污染的 serious polluted/heavily polluted u New Words and Phrasesvdetermining factor 决定因素决定因素 vphotochemical oxidant 光化学氧化物光化学氧化物 vliquid droplet 液体微滴液体微滴 vradioactive substance 放射性物质放射性物质vincomplete oxidization/incomplete combustion 不完全氧化不完全氧化 vautomobi
3、le exhaust 汽车尾气汽车尾气u New Words and PhrasesWhat is air pollution?Air pollution is normally defined as air that contains one or more chemicals in high enough concentration to harm humans,other animals,vegetation or materials.什么是大气污染?什么是大气污染?大气污染大气污染通常是指空气中一种或通常是指空气中一种或多种化学物质富集到高浓度,以至于对人类、其它多种化学物质富集到高浓
4、度,以至于对人类、其它动物、植物或材料造成了危害。动物、植物或材料造成了危害。u TextA primary air pollutant is a chemical added directly to the air that occurs in a harmful concentration.It can be a natural air component,such as carbon dioxide,that rise above its normal concentration,or something not usually found in the air,such as a le
5、ad compound emitted by cars burning leaded gasoline.一次大气污染物一次大气污染物是指直接排放到大气中的污染物质是指直接排放到大气中的污染物质,其浓度达到了造成危害的程度。其浓度达到了造成危害的程度。一次大气污染物中有的是大气中自然组成成分(如二一次大气污染物中有的是大气中自然组成成分(如二氧化碳)浓度超过了其正常浓度,或一些通常大气中氧化碳)浓度超过了其正常浓度,或一些通常大气中没有的物质如汽车使用含铅汽油时燃烧所排放的含铅没有的物质如汽车使用含铅汽油时燃烧所排放的含铅化合物。化合物。vA secondary air pollutant is
6、 a harmful chemical formed in the atmosphere through a chemical reaction among air components.v次生空气污染物次生空气污染物是空气中的各组分在大气中相互发是空气中的各组分在大气中相互发生化学反应所产生的有害物质。生化学反应所产生的有害物质。uSecondary pollutants include some particles formed from gaseous primary pollutants and compounds in photochemical smog,such as nitro
7、gen dioxide,ozone and peroxyacetyl nitrate(PAN).u二次污染物包括一些由气态一次污染物形成的颗粒物二次污染物包括一些由气态一次污染物形成的颗粒物和光化学烟雾化合物,如二氧化氮、臭氧和硝酸过氧化和光化学烟雾化合物,如二氧化氮、臭氧和硝酸过氧化乙酰乙酰(PAN)。uNote that some pollutants may be both primary and secondary:that is,they are both emitted directly and formed from other primary pollutants.u需要注意的
8、是,一些污染物可能是既是一次污染物又是需要注意的是,一些污染物可能是既是一次污染物又是二次污染物:换言之,它们既可直接排放,又能由其他二次污染物:换言之,它们既可直接排放,又能由其他一次污染物形成。一次污染物形成。vSerious air pollution usually results over a city or other area that is emitting high levels of pollutants during a period of air stagnation.v在城市或其它区域上空发生的严重大气污染通常是在城市或其它区域上空发生的严重大气污染通常是由于在由于在
9、空气停滞期空气停滞期所排放的高浓度的污染物造成的所排放的高浓度的污染物造成的。vThe geographic location of some heavily populated cities,such as Los Angeles and Mexico City,makes them particularly susceptible to frequent air stagnation and pollution buildup.v一些人口稠密的城市的地理位置,例如洛杉矶和墨西哥城,使一些人口稠密的城市的地理位置,例如洛杉矶和墨西哥城,使他们特别容易受到频繁的空气停滞和空气污染累积的影响。他
10、们特别容易受到频繁的空气停滞和空气污染累积的影响。vBy themselves,measured concentrations tell us nothing about the danger caused by pollutants,because threshold levels,synergy,and biological magnification are also determining factors.v测量所得的污染物浓度本身并不能告诉我们这些污染物所造成测量所得的污染物浓度本身并不能告诉我们这些污染物所造成的危害的信息,因为的危害的信息,因为临界浓度、协同作用临界浓度、协同作用
11、还有还有生物放大效应生物放大效应都都是决定因素。是决定因素。Major air pollutants1.Carbon oxides:carbon monoxide,carbon dioxide.碳氧化物:碳氧化物:一氧化碳一氧化碳 ,二氧化碳。二氧化碳。2.Sulfur oxides:sulfur dioxide,sulfur trioxide.硫氧化物硫氧化物:二氧化硫二氧化硫 ,三氧化硫。三氧化硫。3.Nitrogen oxides:nitrous oxide,nitric oxide,nitrogen dioxide.氮氧化物:氮氧化物:一氧化二氮一氧化二氮,一氧化氮一氧化氮,二氧化氮二
12、氧化氮.4.Hydrocarbons(organic compounds containing carbon and hydrogen):methane,butane,benzene.碳氢化合物(有机含有碳氢化合物):碳氢化合物(有机含有碳氢化合物):甲烷甲烷 丁烷丁烷 苯。苯。v5.Photochemical oxidants:ozone,PAN(a group ofPeroxyacylnitrates),and various aldehydes.光化学氧化剂:臭氧,一组过氧酰基硝酸酯光化学氧化剂:臭氧,一组过氧酰基硝酸酯 和各种醛和各种醛Major air pollutantsvNear
13、 the ground,ozone is a colourless,gaseous secondary pollutant.It is formed by chemical reactions between reactive organic gases and oxides of nitrogen in the presence of sunlight.靠近地面时臭氧是一种无色的气态的二次污染物。靠近地面时臭氧是一种无色的气态的二次污染物。它是它是由活性有机气体和氮氧化物在阳光下的化学反应形成的。由活性有机气体和氮氧化物在阳光下的化学反应形成的。v Ozone is one of the i
14、rritant secondary pollutants in photochemical smog and is often used as a measure of it.臭氧是光化学烟雾中的一种刺激性的二次污染物,通常臭氧是光化学烟雾中的一种刺激性的二次污染物,通常是作为光化学烟雾的衡量指标。是作为光化学烟雾的衡量指标。vOzone is strongly oxidising and can irritate the eyes and the respiratory tract.It also damages plants.臭氧具有强烈的氧化性并能刺激眼睛和呼吸道臭氧具有强烈的氧化性并能
15、刺激眼睛和呼吸道.它也会破它也会破坏植物。坏植物。OzonevThe formation of ozone in the upper levels of the atmosphere or“stratosphere”is by a different process.在上层大气或在上层大气或“同温层同温层”的臭氧的形成过程不同。的臭氧的形成过程不同。vOzone there is not regarded as a pollutant because it is produced naturally.臭氧不被视为一种污染物是因为它是自然产生的。臭氧不被视为一种污染物是因为它是自然产生的。vIt
16、 is important in absorbing harmful ultraviolet radiation and preventing it from reaching the earth.它吸收有害的紫外线辐射、阻止紫外线到达地球。它吸收有害的紫外线辐射、阻止紫外线到达地球。PAN(a group of Peroxyacyl nitratesvPeroxyacetyl nitrate is a secondary pollutant present in photochemical smog.It is thermally unstable and decomposes into p
17、eroxyethanoyl radicals and nitrogen dioxide gas.vPeroxyacetyl nitrate,or PAN,is an oxidant more stable than ozone.Hence,it is better capable of long-range transport than ozone.It serves as a carrier for oxides of nitrogen(NOx)into rural regions and causes ozone formation in the global troposphere(对流
18、层).Photochemical smog 1formation 大气中碳氢化合物(HC)、氮氧化物(NOX)等一次污染物在阳光照射下,发生光化学反应产生二次污染物,这种由参加反应的一、二次污染物的混合物(包括气体污染物和气溶胶)形成的烟雾污染现象,称为光化学烟雾光化学烟雾。Practice:Translate the above to EnglishvPhotochemical smog is formed when sunlight interacts with certain chemicals in the atmosphere.Ozone is the main component
19、in this type of air pollution.Ozone in the stratosphere(平流层)protects us against harmful ultraviolet radiation,but on the ground,it is hazardous to human health.Ground-level ozone forms when motor vehicle emissions containing nitrogen oxide and volatile organic compounds(produced from paint and evapo
20、ration of fuel and solvents)react in the presence of sunlight.Read more:Effect of Photochemical Smog|eH http:/ characteristic:blue smog,strong oxidability,irritative,low visibility.source:industrial waste gases and motor vehicle exhaust.The previous section suggests that the development of photochem
21、ical smog is primary determined by abundance of nitrogen oxides and volatile organic compounds in the atmosphere and the presence of particular environmental conditions.前一部分表明,光化学烟雾的发展主要是由大前一部分表明,光化学烟雾的发展主要是由大气中大量的氮氧化物和挥发性有机化合物和特气中大量的氮氧化物和挥发性有机化合物和特定环境条件的存在所决定。定环境条件的存在所决定。photochemical smog conditio
22、n:NOx CHUVLight blue smogO3过氧酰基硝酸酯 other主要为过氧乙主要为过氧乙酰硝酸酯酰硝酸酯PAN PAN(peroxyacety(peroxyacetyl nitratel nitrate 醛类醛类aldehydesaldehydes 、酮、酮类类 ketonesketones、过、过氧化氢等氧化氢等 NOX;CH;strong sunlight.the indexes of formation:O3、PAN and other product.greenhouse gasvA greenhouse gas(sometimes abbreviated GHG)is
23、 a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range.This process is the fundamental cause of the greenhouse effect.1 The primary greenhouse gases in the Earths atmosphere are water vapor,carbon dioxide,methane,nitrous oxide,and ozone.Volatile organic compoundvV
24、olatile organic compounds(VOCs)are organic chemicals that have a high vapor pressure at ordinary room temperature.Their high vapor pressure results from a low boiling point,which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and enter the s
25、urrounding air.For example,formaldehyde,which evaporates from paint,has a boiling point of only 19 C(2 F).Other Volatile organic compounds contain:Benzene,Chlorofluorocarbons and chlorocarbons,Methylene chloride,Perchloroethylene,MTBE(tert-Butyl Methyl ether)Chlorofluorocarbons and chlorocarbonsvChl
26、orofluorocarbons(CFCs),which are banned or highly regulated because it is harmful to the ozone layer,were widely used cleaning products and refrigerants.Tetrachloroethene is used widely in dry cleaning and by industry.Persistent organic pollutants(POPs)vPersistent organic pollutants(POPs)are organic
27、 compounds that are resistant to environmental degradation through chemical,biological,and photolytic processes.Because of this,they have been observed to persist in the environment,to be capable of long-range transport,bioaccumulate in human and animal tissue,biomagnify in food chains,and to have p
28、otentially significant impacts on human health and the environment.Acid rainv6.Particulates(solid particles or liquid droplets suspended in air):smoke,dust,soot,asbestos,metallic particles(such as lead,beryllium cadmium),oil,salt spray,sulfate salts.颗粒(在空气中的固体颗粒或液滴悬浮):颗粒(在空气中的固体颗粒或液滴悬浮):烟雾,尘埃,油烟,石棉,
29、金属粒子(例如铅,镉烟雾,尘埃,油烟,石棉,金属粒子(例如铅,镉铍),石油,盐雾,硫酸盐。铍),石油,盐雾,硫酸盐。Major air pollutantsv(Asbestos,5.5FeO,1.5MgO,8SiO2,H2O)v绝热材料绝热材料v石棉公害石棉公害 石棉石棉v7.Other inorganic compounds:asbestos,hydrogen fluoride,hydrogen sulfide,ammonia,sulfur acid,nitric acid.其他无机化合物:石棉,氟化氢,硫化氢,氨气,硫酸,其他无机化合物:石棉,氟化氢,硫化氢,氨气,硫酸,硝酸。硝酸。v8.
30、Other organic compounds:pesticides,herbicides,various alcohols,acids,and other chemicals.其他有机化合物:杀虫剂,除草剂,各种醇,酸和其他其他有机化合物:杀虫剂,除草剂,各种醇,酸和其他化学品。化学品。v9.Radioactive substances:tritium,radon,emissions from fossil fuel and nuclear power plants.放射性物质:放射性物质:氚,氡,氚,氡,化石燃和核能发电厂排放物化石燃和核能发电厂排放物。v10.Heat.10.热。热。v1
31、1.Noise.11.噪声。噪声。Major air pollutantsvCarbon oxides Carbon Monoxide(CO):Forest fires and decaying organic matter;incomplete combustion of fossil fuels(about two-thirds of total emissions)and other organic matter in cars and furnaces;cigarette smoke 森林火灾和腐烂的有机物质森林火灾和腐烂的有机物质;不完全燃烧化石燃料不完全燃烧化石燃料(约占三分之二的
32、总量)和其他来自汽车和熔炉的有(约占三分之二的总量)和其他来自汽车和熔炉的有机质机质;香烟烟雾香烟烟雾.The major sources of these pollutantsvCarbon dioxide(CO2):Natural aerobic respiration of living organisms;burning of fossil fuels 自然有氧呼吸的生物体自然有氧呼吸的生物体;燃烧化石燃料燃烧化石燃料vSulfur oxides (SO2 and SO3):Combustion of sulfur-containing coal and oil in homes,in
33、dustries and power plants;smelting of sulfur-containing ores;volcanic eruptions 家庭、工厂和发电厂燃烧含硫的煤和石油;冶炼含硫家庭、工厂和发电厂燃烧含硫的煤和石油;冶炼含硫矿石;火山爆发矿石;火山爆发.The major sources of these pollutantsvParticulates dust soot and oil:煤烟粉尘颗粒物和煤烟粉尘颗粒物和石油石油 forests fires,wind erosion,and volcanic eruptions;coal burning;farmin
34、g,mining construction,road building,and other land-clearing activities;chemical reactions in the atmosphere;dust stirred up by automobiles;automobile exhaust;coal-burning electric power and industrial plants 森林火灾,风蚀,和火山爆发森林火灾,风蚀,和火山爆发;燃煤燃煤;农业,采矿工程,农业,采矿工程,道路建设,以及其他土地清理活动道路建设,以及其他土地清理活动;大气中的化学反大气中的化学
35、反应;汽车引发的粉尘应;汽车引发的粉尘;汽车尾气;燃煤电力厂房和;汽车尾气;燃煤电力厂房和工业厂房工业厂房.The major sources of these pollutantsNitrogen oxides(NO and NO2):High-temperature fuel combustion in motor vehicles and industrial and fossil fuel power plants;lighting机动车辆高温燃料燃烧,工业和矿物燃料发电厂机动车辆高温燃料燃烧,工业和矿物燃料发电厂;照明照明Photochemical oxidants 光化学氧化剂光化
36、学氧化剂Sunlight acting on hydrocarbons and nitrogen oxides碳氢化合物和氮氧化物在阳光下反应碳氢化合物和氮氧化物在阳光下反应.The major sources of these pollutantsvHydrocarbons 碳氢化合物碳氢化合物 Incomplete combustion fossil fuels in automobiles and furnaces;evaporation of industrial solvents and oil spills;tobacco smoke;forest fires;plant deca
37、y(about 85 percent of emissions)不完全燃烧化石燃料的汽车和火炉;蒸发的工业溶剂不完全燃烧化石燃料的汽车和火炉;蒸发的工业溶剂和石油泄漏;烟草烟雾;森林火灾;植物的腐烂(大和石油泄漏;烟草烟雾;森林火灾;植物的腐烂(大约约%85的排放)的排放).The major sources of these pollutantsvPesticides and herbicides:杀虫剂和除草剂杀虫剂和除草剂 Agriculture;forestry;mosquito control农业农业;林业林业;蚊虫控制蚊虫控制vAsbestos:石棉石棉 Asbestos mini
38、ng;spraying of fireproofing insulation in buildings;deterioration of brake linings 石棉开采石棉开采;防火隔热建筑的喷漆防火隔热建筑的喷漆;制动片的变质制动片的变质vMetals and Metal Compounds:Mining;industrial processes;coal burning;automobile exhaust.挖掘;工业生产过程挖掘;工业生产过程;燃煤燃煤;汽车尾气汽车尾气.The major sources of these pollutantsvHydrogen Sulfide(H
39、2S):Chemical industry;petroleum refiningvAmmonia(NH3):Chemical industry;petroleum refining 化学工业化学工业;石油炼制石油炼制vSulfuric Acid(H2SO4):Reaction of sulfur trioxide and water vapor in atmosphere;Chemical industryvNitric Acid(HNO3):Reaction of sulfur trioxide and water vapor in atmosphere;Chemical industry三
40、氧化硫和水汽在大气中反应三氧化硫和水汽在大气中反应;化学工业化学工业.The major sources of these pollutantsvNoise:Automobiles,airplanes,and trains;industry;construction汽车,飞机,列车汽车,飞机,列车;产业建设产业建设vOther Inorganic Hydrogen Fluoride(HF):Petroleum refining;glass etching;aluminum and fertilizer production石油炼制石油炼制;玻璃刻蚀玻璃刻蚀;铝和化肥生产铝和化肥生产.The m
41、ajor sources of these pollutantsTechnology for control of particulate emissionsvCyclonev旋风除尘器旋风除尘器vElectrostatic precipitatorsv静电沉淀器静电沉淀器vWet scrubber/wet collectorv湿式除尘器湿式除尘器vFabric filtersv袋式过滤器袋式过滤器vBiofiltrationv生物过滤生物过滤控制工业来源的颗粒物的排放的主要方法是利用控制工业来源的颗粒物的排放的主要方法是利用旋风分旋风分离器、静电除尘器、布袋过滤器和洗涤器离器、静电除尘器、布
42、袋过滤器和洗涤器。Technology of Air Pollution ControlBiofiltration:An Innovative Air Pollution Control Technology for VOC Emissions.生物过滤:一种创新的大气挥发性有机物污染控制技术生物过滤:一种创新的大气挥发性有机物污染控制技术The principal means for control of particulate emissions from industrial sources are cyclones,electrostatic precipitators,fabric
43、filters and scrubbers.BiofiltrationvBiofiltration is a pollution control technique using material to capture and biologically degrade process pollutants.v生物过滤是使用材料来捕获和生物降解污染物的一生物过滤是使用材料来捕获和生物降解污染物的一种污染控制技术。种污染控制技术。vCommon uses include processing waste water,capturing harmful chemical or silt from su
44、rface runoff,and microbiotic oxidation of contaminants in airv常见的用途包括处理废水、从地表径流或泥沙中捕常见的用途包括处理废水、从地表径流或泥沙中捕捉有害化学物质和空气中污染物的微生物氧化。捉有害化学物质和空气中污染物的微生物氧化。Flue-gas desulfurizationvFlue-gas desulfurization(FGD)is a set of technologies used to remove sulfur dioxide(SO2)from exhaust flue gases of fossil-fuel
45、power plants,and from the emissions of other sulfur oxide emitting processes.v烟气脱硫是用于除去烟气脱硫是用于除去SO2的一系列技术,而的一系列技术,而SO2主要来主要来源于化石燃料发电厂的烟道气体和其他排放源于化石燃料发电厂的烟道气体和其他排放SO2的工程的工程。Basic control equipment options for gaseous emissions from process industries 工业过程气态污染物的基本控制设备的选择vCondensation v冷凝冷凝vAbsorption
46、v吸收吸收vAdsorptionv吸附吸附vCombustion or incineration.v燃烧燃烧观看视频v1.复习本课中学习的关于空气污染的专业术语。v2.查找英文资料,了解典型的空气污染物处理技术。Homework 1.Translate the following sentences 2.P 53 EX 1,2,4.阅读并翻译Translation1.产生二氧化硫的主要人类活动是含硫矿石的冶炼和矿物燃料的燃产生二氧化硫的主要人类活动是含硫矿石的冶炼和矿物燃料的燃烧。烧。2.悬浮在空中不仅有气态污染物,还有固体或液体微粒。悬浮在空中不仅有气态污染物,还有固体或液体微粒。3.颗粒物
47、可能是一次污染物,如烟雾粒子,或气态污染物经化学反应颗粒物可能是一次污染物,如烟雾粒子,或气态污染物经化学反应形成的二次污染物。形成的二次污染物。4.大气中主要存在的氮氧化物有一氧化氮大气中主要存在的氮氧化物有一氧化氮(NO)、二氧化氮、二氧化氮(NO2)和一和一氧化二氮氧化二氮(N2O)。5.这些氮氧化物在产生光化学烟雾的化学反应中发挥重要作用。这些氮氧化物在产生光化学烟雾的化学反应中发挥重要作用。6.一氧化碳是一种无臭、无色的气体,由不完全氧化一氧化碳是一种无臭、无色的气体,由不完全氧化(燃烧燃烧)产生。产生。7.臭氧是二次污染物的一个重要的例子,它是构成光化学烟雾的众多臭氧是二次污染物的
48、一个重要的例子,它是构成光化学烟雾的众多二次污染物之一。二次污染物之一。8.甲醛是室内气体中最主要的致癌气体之一,多出现于新装修甲醛是室内气体中最主要的致癌气体之一,多出现于新装修的房子里。的房子里。vPrecision and accuracy 精确度和准确度 v bulk collection 大量的搜集vmatric material 基体材料 v ananlytical sequence 分析结果 vMultivariate statistics 多变量的统计 v interactive effect 相互间的影响 vinsofar 在.的范围 v overall analytical
49、 scheme 整体分析计划Answer to last homeworkv灵敏度 sensitivity v采样 sample collection v真实时间 real time v样品预处理 pretreatment of the sample v 稳定性 stabilityv曲线拟合 curve-fitting v吸附 adsorb adsorption v累积 accumulate accumulationv分析评价 analytical evaluation v 物理分离 physical separationv因次图 dimension graph v标准方差 standard variance2020/11/548谢谢观赏!
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