环境工程学(第5章PPT课件

1、大气结构垂直分层大气结构垂直分层第第1页页/共共17页页 第二节 大气污染一、大气污染定义 Air Pollution may be defined as any atmospheric condition in which substances are present at concentrations high enough above their normal ambient levels to produce a measurable effect on man, animals, vegetation, or materials.二、大气污染物种类n颗粒污染物1.粉尘（dust）2.

2、烟（fume）3.飞灰（flyash）4.黑烟（smoke）5.雾（fog）6.总悬浮微粒（TSP）n气态污染物 含硫、氮化合物，COCOx ，CmHn，卤素经合物（表6-2）三、大气污染物的来源和发生量n自然过程n人类活动第第2页页/共共17页页 Sources of airborne pollution in Asia are many: power generation, industry, traffic, home cooking, and biomass burning第第3页页/共共17页页四四. . 空气污染系统空气污染系统（Air Pollution Systems）第第4页

3、页/共共17页页 Emission sourcesAtmosphere Receptors pollutantsmixed and chemical transformation Emission sources Source control Atmosphere Receptors Receptors Humans Animals Plants MaterialsresponseAutomatic controlLegislative action第第5页页/共共17页页v Pollutants released directly into the atmosphere in their u

4、nmodified forms and in sufficient quantities to pose a health risk Sources of Primary Air Pollutants五.一次大气污染物PollutantSourcesCarbon monoxideIncomplete burning of fossil fuels, Tobacco smokeHydrocarbonsIncomplete burning of fossil fuels, Tobacco burningParticulatesChemicals, Burning fossil fuels, Far

5、ming operations, Industrial wastes, Building demolitionSulfur dioxideBurning fossil fuels, Smelting oreNitrogen compoundsBurning fossil fuels第第6页页/共共17页页六. 光化学烟雾:Secondary air pollutants are compounds that results from the interaction of various primary air pollutants.Photochemical smog is a mixture

6、 of pollutants resulting from the interaction of nitrogen oxides and hydrocarbons with ultraviolet light.The two most destructive components of photochemical smog are ozone(O3) and peroxyacetylnitrates(PAN，过氧乙酰硝酸酯)第第7页页/共共17页页 NO2（微量） NO2 + UV NO2 NO2 NO + O O + O2 O3 O3 + NO NO2 + O2 O3 O3 + HC 醛类及

7、其它氧化物 醛类 复杂的有机化合物 刺激眼睛 NO 汽车排气 HC NO2 太阳 紫外光 紫外光 HC + O2 + NO2 + UV O3 + 甲醛 + PAN + 氧化产物 O3 PAN 甲醛、 丙稀醛等 伤害植物 伤害植物 刺激眼睛 刺激眼睛 氧化产物 聚合与核长大 气溶胶 光雾 光化学烟雾形成过程第第8页页/共共17页页光化学烟雾实例第第9页页/共共17页页Acid Deposition is the accumulation of potential acid-forming particles on a surface.Acids result from natural cause

8、s and from human activities.The acid-forming reactants are classified as wet or dry. 七.酸沉降第第10页页/共共17页页 Molecules from natural sources, power plants, and internal combustion engines react to produce the chemicals that are the source of acid deposition.第第11页页/共共17页页酸雨的危害水的低pH值使得鱼的骨骼畸形生长，最终导致死亡引起树木的大量

9、不正常死亡严重腐蚀建筑物第第12页页/共共17页页PH5.6 PH7.0 N/A Taiwan Acid rain distribution in 80s PH7.0 PH7.0 PH5.6 PH5.0 PH4.5 PH4.0 Acid rain distribution in middle 90s 中国酸雨的分布变化第第13页页/共共17页页我国酸雨的化学特征第第14页页/共共17页页 第三节 大气质量控制标准一、大气环境质量标准n大气环境质量标准（GB3095-82）I.一级标准II.二级标准III.三级标准n大气质量分类 - 功能分区I.一类-执行一级标准II.二类-执行二级标准III.三类-执行三级标准二、空气污染排放标准按污染扩散规律推算排放标准K值法计算排放标准 Q = K*10-3H2（m3/h） K：地区系数 H = Hs + H Hs：烟囱实际高度； H：烟柳抬升高度总量控制标准第第15页页/共共17页页 第四节 大气污染控制的基本方法一、大气污染控制的含义1.从立法角度，用法律来限制或禁止污染物的扩散。2.控