air+pollutant.ppt

Unit 17 Air Pollutants pollutant n.污染物 While the atmosphere’s ozone protects?us?from?the?sun’s?rays, ?ground-level ozone?is?a?pollutant. But more and more people believe that corruption does far more harm than good. harm vt.伤害 How do you explain this phenomenon?? phenomenon n.现象 primary adj.主要的，初步的，初级的 Distinction? should be made between the primary and secondary?tasks. concentration n.浓度 A?gas?in?solution?diffuses? from a?region?of?greater?to?one?of?less? concentration. Why did?you?emit?that?scream? emit vt. 发出，散发 In?my?opinion?all?this?is?of?secondary?importance? secondary adj.二级的，中级 What do?we?know?about?methane? methane n.甲烷，沼气 butane n.丁烷 there’s also?propane?and?butane,?and?gases?that?derive from the same?processes?that?make?the?oil. benzene n.苯 The?chemist?Kekule?discovered?the?ring?structure?of?benzene?in?a?dream.? dust 灰尘 His?car?stood?in?the garage?for a?long?time,?with thick?dust. ? air pollution 空气污染? carbon monoxide 一氧化碳 carbon monoxide sulfur trioxide 三氧化硫 nitrogen dioxide 二氧化氮? carbon monoxide 一氧化二氮 Inorganic compound 无机化合物 dinitrogen oxide hydrogen fluoride 氟化氢? carbon monoxide 硫化氢 hydrogen sulfide When air contains one or more chemicals and harms humans, other animals,plants or materials,the phenomenon is called air pollution. 当空气中含有一种或者多种化学物质，并且会伤害人体，其他动植物或材料，这种现象叫做空气污染。 There are two major types of air pollutants. A primary air pollutant is a chemical added directly to the air and it occurs in a harmful concentration.For example,when carbon dioxide is above its normal concentration， 空气污染主要分2类： 一次大气污染物是化学品直接进入空气并且到达了有害的浓度，比如，当二氧化碳浓度高于它的正常浓度， it is considered to be a air pollutant.A lead compound emitted by cars is also the air pollutant. 这被认为是大气污染。汽车释放的含铅化合物尾气也是一种大气污染物。 A secondary air pollutant is formed in the atmospfere through a chemical reaction. Major air pollutants are as following: 二次大气污染物是通过化学反应在大气中形成的。 主要的大气污染如下： 1.Carbon oxides:carbon monoxide(CO),carbon dioxide(CO2) 2.Sulf