"Air Pollution and Protection" PPT

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"Air Pollution and Protection" PPT

Part 1: What is air pollution?

1. What is air pollution?

The air has a certain self-purification ability and can remain clean and fresh under normal circumstances.

Air pollution occurs when pollutants enter the air and exceed the self-purification capacity of the air, endangering human comfort and health or harming the environment.

2. Sources of pollutants in the air:

Automobile exhaust

Exhaust gas and smoke emitted from factories

Main pollutants:

Smoke, sulfur dioxide, carbon oxides (mainly CO), nitrogen oxides (mainly NO and NO2), hydrocarbons, etc.

expand:

①. Car exhaust:

The gas emitted by cars is called car exhaust. Main harmful components: carbon monoxide, nitrogen oxides, soot, sulfur dioxide, etc. is one of the main sources of air pollution.

②. Inhalable particulate matter:

Particles with a particle size below 10 microns, which are not easy to settle to the ground under the action of gravity and can float in the air for a long time, are called respirable particles. Including smoke from factory chimneys, dust rolled up from the land, roofs, roads or construction sites, scales from the wings of butterflies, pollen and bacteria from plants, etc. Affect life and production.

Air pollution and protection PPT, Part 2: How to prevent and control air pollution

Main measures to prevent and control air pollution:

1. Reduce the emission of pollutants.

2. Reasonably plan industrial areas and non-industrial areas.

3. Increase efforts in afforestation.

think

What measures can we take to reduce air pollution in our daily lives?

Air Pollution and Protection PPT, Part 3: Air Quality Index

Air quality index: It simplifies the concentrations of several routinely monitored air pollutants into numerical forms, and expresses the degree of air pollution and air quality status in grades.

Pollutants currently included in the air pollution index include: sulfur dioxide, nitrogen dioxide, respirable particulate matter, ozone and carbon monoxide.

Air Pollution and Protection PPT, Part 4: Global Atmospheric Environmental Issues

Greenhouse effect, ozone hole and acid rain, etc.

(1) Acid rain

1. What is acid rain?

Acidic precipitation with a pH lower than 5.6 is called acid rain. (Explanation: Natural precipitation becomes weakly acidic. Because the air contains a small amount of carbon dioxide, it becomes weakly acidic when dissolved in water)

2. Causes of acid rain:

Precipitation contains sulfur dioxide, nitrogen oxides, etc. in the air dissolved in it. Mainly sulfuric acid and nitric acid. The smaller the pH, the stronger the acidity.

my country's energy structure is dominated by coal, so the emissions of carbon dioxide, sulfur dioxide and nitrogen oxides are relatively large. After testing, acid rain accounts for about 44.5% of precipitation.

3. The harm of acid rain:

It endangers health, pollutes waters, acidifies soil, damages crops and forest growth, harms fisheries, and corrodes buildings, industrial equipment and cultural monuments.

(2) Protect the ozone layer

1. Ozone - O3

Physical properties: blue, fishy-smelling gas

Chemical properties: Strong oxidizing property, unstable

2. Do you know how ozone is produced?

3. Do you know where ozone is distributed?

90% of the ozone in the atmosphere accumulates in the stratosphere, the ozone layer, 20-35 kilometers above the ground.

discuss

What is the impact of the ozone layer on humans and living things?

High-energy ultraviolet rays in sunlight can cause damage to human skin, eyes, and even the immune system; they can affect the growth of aquatic organisms; they can destroy chlorophyll in plants and hinder the photosynthesis of crops and trees.

The role of the ozone layer

The ozone layer can block and weaken excessive ultraviolet rays, protecting humans and other living things.

(3) Greenhouse effect

Explore why the greenhouse effect occurs?

Activity: Feel what the greenhouse effect is

Take two plastic cups, fill each half with water, cover one cup with a piece of glass, and expose them to the sun for about an hour at the same time. Measure the water temperatures separately for comparison.

Measure the water temperature: The water temperature in the cup of _______ is high.

The reasons are:

After sunlight passes through the glass at the mouth of the cup, it will increase the temperature inside the cup, but the reflection of the water in the cup rarely penetrates the glass. This is the greenhouse principle.

Air Pollution and Protection PPT, Part 5: Class Discussion

Discussion: What are the pros and cons of the greenhouse effect? What measures can we take to prevent the greenhouse effect from increasing?

Pros: A moderate greenhouse effect can ensure a stable temperature on the earth, suitable for the survival of animals and plants.

Disadvantages: 1. The intensification of the greenhouse effect causes the earth's surface temperature to rise, so the icebergs and glaciers at the earth's poles begin to melt, causing sea levels to rise, which may eventually submerge coastal cities and farmland.

2. Lead to global climate warming, thereby causing damage to the ecological balance.

3. The occurrence and spread of some epidemics

Measures: ① Control the burning of fossil fuels, rationally develop and utilize fuels, and find new energy sources such as solar energy, biomass, geothermal, etc. to reduce carbon dioxide emissions ② Protect forests and vegetation, prohibit deforestation, plant trees, and use Forests conserve water and regulate temperature. ③Control population surge.

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Update Time: 2024-09-05

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