大气污染与防治.ppt

大气污染及其防治Air pollution and Environmental protection
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Air is essential to anisms on earth. For human beings, air for breathing is more important than our daily bread. The air we inhale is made up of 21% oxygen and % carbon dioxide. We exhale 17% oxygen and 4% carbon dioxide. Oxygen is needed for the metabolic processes which occur within the cells. An adult inhales approximately 14000 liters of air daily, which is equivalent to the volume of about 50 bathtubs.
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Visibility impaired by air pollution.
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A clear view and clouded view: what air pollution does to visibility.
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Smoky vehicles are a problem.
Smoky vehicles will have to undergo tests on a tamper-proof treadmill from mid-1999. (HK)
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讲授内容Content of Discussion
第二部分:大气污染物各论



第一部分:概述



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概述--大气的组成及结构
干洁空气的组成:
氮(N2)%
氧(O2)%
氩(Ar)%
%。
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(1)对流层:大气圈最下一层,层内气流对流强烈,气温随高度而降低。 (2)平流层:对流层顶到50-55km高处的大气层,这里空气以平流运动为主,垂直运动很少,故叫平流层。 (3)中间层:从平流层顶到85km高度属中间层。此层气温又随高度增高而下降,空气有较强的对流运动。 (4)热成层:中间层之上,上界可达800 km高处。由于原子氧吸收了太阳紫外光的能量, 使此层的温度随高度的上升迅速升高,故又叫暧层或热层。又因为太阳和其它星球射来的各种射线的作用, 此层大部分空气发生电离,具有较高密度的带电粒子,故又称电离层。 (5)逸散层:逸散层是大气圈的最外层, 它的厚度大约从800 km一直延到2000-3000 km高处, 是地球大气向外层空间过渡的层次。
概述--大气的组成及结构
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概述--大气污染的含义
大气污染——
是指大气中污染物质的浓度达到了有害程度,以致破坏生态系统和人类正常生存和发展的条件,对人和物造成危害的现象。
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形成大气污染的三个要素是: 污染源 大气状态 受体大气污染的三个过程是: 污染物排放 大气运动的作用 对受体的影响。
概述--大气污染的含义
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