Smog and acid rain message. Why is acid rain dangerous?

Hydrometeors with a pH below the norm, characterized by the presence of harmful substances, are acid rain. It can be snow, fog, rain or hail. Any of the species in the atmosphere and on earth can lead to an ecological disaster.

A couple of decades ago, the negative impact of this phenomenon worried only the scientific community. Now it causes great concern not only in the scientific world, but also among the general public, as well as various government agencies.

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Problem history

Effect of precipitation with low water index on environment was designated more than a hundred years ago by the British chemist R. Smith. The scientist was interested in smog and the substances in its composition. Thus was born the concept of acidity, which was immediately rejected by the advanced scientific community that time. His colleague spoke again about the hydrogen index 10 years later.

Chemist and engineer S. Arrhenius published a message about chemical substances ah, which can donate a hydrogen cation. He again drew the attention of scientists to the harmfulness of such precipitation, to what danger the phenomenon poses, and became the man who introduced the term: acid / base. Since then, these indicators have been considered the level of acids in the aquatic environment.

Svante Arrhenius

The main elements of hydrometeors are acid components. This substance is monobasic acids (sulfuric and nitric). Precipitation based on interacting gases (chlorine and methane) is less common. What they will be in composition depends on what chemical waste is in combination with water.

In short, the mechanism for the formation of the phenomenon is the combination of oxides that have entered the atmosphere with water molecules. During the interaction, the formation of chemical components - sulfuric and nitric acid.

Reasons for the appearance

Low pH hydrometeors are caused by elevated concentrations of sulfur and nitrogen oxides in the atmosphere. Compounds enter the atmosphere naturally or artificially created by man. Natural sources are:

The main reason is human activity. What is it? The factor that causes precipitation is air pollution. The most well-known pollutants are road transport and thermal power plants. A significant role in the occurrence of oxides in the atmosphere is played by the emission of industrial enterprises, nuclear tests. Hydrometeors with acid are formed in in large numbers in places where space rockets are launched.

Hydrometeors with acids are not only snow or fog, but also dust clouds. They form when toxic vapors rise into the air during dry weather.

The main reasons lie in the huge emissions of harmful substances into the atmosphere. The main ones here can be called chemical production, oil and gasoline storage facilities, solvents used by enterprises and in everyday life more and more actively every year. The problem of acid precipitation is very acute in areas where metal processing is concentrated. Production leads to the appearance of sulfur oxides in the atmosphere, which cause irreparable damage to flora and fauna.

Of all the above, the greatest danger is the phenomenon associated with atmospheric pollution by toxic waste from internal combustion engines. The gases rise into the air and cause oxidation. One of the reasons is nitrogen compounds released during the production of materials for the construction, construction of buildings, road construction. They also often result in low pH precipitation.

Interesting Facts:

• On Venus, smog is caused by the concentration of sulfuric acid in the atmosphere.
• On Mars, limestone and marble rocks are also corroded by poisonous acid rain in the form of fog.

The facts about such precipitation say that the problem of acid rain has existed for millions of years. On Earth, their influence is known from the prehistoric period. Almost 300 million years ago, the formation of acid rain led to the extinction of 90 percent of species.

Consequences for nature

Precipitation with a low pH level poses a risk of global disturbances in the biosphere. What harm do they do? About what are negative consequences precipitation data, environmentalists say:

Consequences for modern humanity

Unfortunately, the substance that makes the greatest contribution to the formation of acid precipitation is only increasing in the atmosphere every year. acid rain as a global environmental problem were identified clearly and seriously. Their most frequent formation is noted in Denmark, Sweden, Norway and Finland. Why do the Scandinavian countries suffer the most? There are several reasons for this. First, wind-driven sulfur formations from Central Europe and Britain. Secondly, limestone-poor lakes contribute to acid rain. Reservoirs do not have much capacity to neutralize acids.

In Russia, acid precipitation is becoming more active every year. Environmentalists are sounding the alarm. The atmosphere above megacities is oversaturated with chemical elements and hazardous substances. Especially often acid rain and smog over major cities fall in calm weather. In the Arkhangelsk region, acid precipitation is caused by the combustion of low-quality fuel. The problem of environmental pollution in the Arkhangelsk region has not changed for the better over the past ten years and is caused by emissions of chemicals into the atmosphere. These are sulfuric and nitric acids, leading to the formation of acid precipitation. Not in the best way the situation is the same in Kazakhstan. There, acid precipitation is associated with the development of mining deposits and the activities of large test sites.

Negative consequences as a result of acid rain are noted in all countries without exception. As a result of their loss, not only the environment suffers. Chronic diseases such as allergies and asthma are exacerbating among the population. The problem is becoming more and more acute, because it has a great Negative influence to health modern people. It has been scientifically proven that they increase the number of oncological tumors. The main cause of precipitation is harmful emissions, which a person is not able to avoid. That is why doctors do not advise getting caught in the rain, protecting yourself with raincoats and umbrellas, and washing thoroughly after a walk. The consequences can be intoxication and the gradual accumulation of toxins in the body.

If you ask a question: what are the areas where acid rain most often forms? The answer to it is quite simple: in the places of greatest concentration of various industries and vehicles. However, it is not so easy to designate an area that is top in this regard. Why is acid rain dangerous? The fact that due to the wind changing its direction, precipitation can fall many kilometers from the metropolis or test site.

Control measures

The causes of acid precipitation have been studied quite fully. Despite this, the problem of acidic hydrometeors is only growing. There is a lot of talk about how to deal with acid rain, but the size of the environmental disaster is only increasing in scale. Examples of solving the problem are demonstrated in many developed countries.

Acid rain as a global environmental problem, along with such a problem as ozone holes, does not have a cardinal and quick solution. Many scientists and environmentalists believe that due to the development of the modern economy, it is generally impossible to do this. To the question: explain, provide evidence, they present graphs and tables of studies that indicate an increase in the degree of danger to nature and man. Now the solution to the problem is to reduce harmful emissions. The cause of the negative phenomenon must be eliminated. To do this, the following methods of dealing with acid rain are used:

• reducing the sulfur content in fuel reduces the causes of acid precipitation;
• the operation of high pipes at enterprises is a modern way to solve the problem;
• technological improvement eliminates the causes and consequences of harmful emissions;
• liming of reservoirs is also an effective way to solve the problem.

It is worth noting that so far there is not even a hint that in the foreseeable future methods will be created to minimize the negative impact of acid precipitation on humans and nature.

AT recent times Quite often you can hear that acid rain has begun. It occurs when nature, air and water interact with various pollutants. Such precipitation gives rise to a number of negative consequences:

• diseases in humans;
• death of agricultural plants;
• reduction of forest areas.

Acid rain is caused by industrial emissions chemical compounds, combustion of oil products and other fuels. These substances pollute the atmosphere. Ammonia, sulfur, nitrogen, and other substances then react with moisture, causing the rain to become acidic.

For the first time in human history, acid rain was recorded in 1872, and by the twentieth century this phenomenon had become very frequent. Acid rain is causing the most damage to the United States and European countries. In addition, environmentalists have developed a special map that shows the areas most exposed to dangerous acid rain.

Causes of acid rain

The causes of poisonous rainfall are anthropogenic and natural. As a result of the development of industry and technology, plants, factories and various enterprises began to emit huge amounts of nitrogen and sulfur oxides into the air. So, when sulfur enters the atmosphere, it interacts with water vapor, forming sulfuric acid. The same thing happens with nitrogen dioxide, nitric acid is formed, falls out along with atmospheric precipitation.

Another source of air pollution is the exhaust gases of motor vehicles. Once in the air, harmful substances are oxidized and fall to the ground in the form of acid rain. The precipitation of nitrogen and sulfur into the atmosphere occurs as a result of the combustion of peat, coal at thermal power plants. A huge amount of sulfur oxide enters the air during the processing of metals. Nitrogen compounds are emitted during the production of building materials.

A certain part of the sulfur in the atmosphere is of natural origin, for example, sulfur dioxide is released after a volcanic eruption. Nitrogen-containing substances can be released into the air as a result of the activity of certain soil microbes and lightning discharges.

The effects of acid rain

There are many consequences of acid rain. People caught in such rain can ruin their health. Given atmospheric phenomenon causes allergies, asthma, cancer. Also, rains pollute rivers and lakes, the water becomes unusable. All inhabitants of the waters are in danger, huge populations of fish can die.

Acid rain falls on the ground and pollutes the soil. This exhausts the fertility of the land, reducing the number of crops. Because the precipitation fall out over vast areas, they negatively affect trees, which contributes to their drying. As a result of the influence chemical elements, metabolic processes in trees change, the development of roots is inhibited. Plants become sensitive to temperature changes. After any acid rain, trees can abruptly shed their leaves.

One of the less dangerous consequences poisonous precipitation is the destruction of stone monuments and architectural objects. All this can lead to the collapse of public buildings and houses of a large number of people.

We need to seriously think about the problem of acid rain. This phenomenon directly depends on the activities of people, and therefore it is necessary to significantly reduce the amount of emissions that pollute the atmosphere. When air pollution is reduced to a minimum, the planet will be less prone to such dangerous precipitation as acid rain.

Solving the environmental problem of acid rain

The problem of acid rain is global in nature. In this regard, it can be solved only if the efforts of a huge number of people are combined. One of the main methods for solving this problem is to reduce harmful industrial emissions into water and air. At all enterprises it is necessary to use cleaning filters and facilities. The most long-term, expensive, but also the most promising solution to the problem is the creation of environmentally friendly enterprises in the future. All modern technologies should be used taking into account the assessment of the impact of activities on the environment.

They do a lot of damage to the atmosphere. modern views transport. It is unlikely that people will give up cars in the near future. However, today new environmentally friendly vehicles. These are hybrids and electric vehicles. Cars like Tesla have already won recognition in different countries peace. They run on special batteries. Electric scooters are also gradually gaining popularity. In addition, do not forget about the traditional electric transport: trams, trolleybuses, metro, electric trains.

We should not forget that air pollution is carried out by people themselves. There is no need to think that someone else is to blame for this problem, and this specifically does not depend on you. This is not entirely true. Of course, one person is not able to release toxic and chemical agents into the atmosphere in large quantities. However, the regular use of passenger cars leads to the fact that you regularly release exhaust gases into the atmosphere, and this subsequently becomes the cause of acid rain.

Unfortunately, not all people are aware of such an environmental problem as acid rain. To date, there are many films, articles in magazines and books about this problem, so each person can easily fill this gap, realize the problem and begin to act for the benefit of its solution.

The main cause of acid rain is air pollution. Ultimately, acid rain could wipe out all life on earth. According to many experts, the only way to change the situation with a significant increase in rain acidity for the better is to reduce the amount of harmful emissions into the atmosphere.

According to the nature of their origin, acid rains are of two types: natural (arise as a result of the activities of nature itself) and anthropogenic (caused by human activities).

Natural acid rain.

There are few natural causes of acid rain:

1) the activity of microorganisms.

A number of microorganisms in the course of their life activity cause destruction organic matter, which leads to the formation of gaseous sulfur compounds, which naturally enter the atmosphere. The amount of sulfur oxides formed in this way is estimated at about 30-40 million tons per year, which is approximately 1/3 of the total;

2) volcanic activity

Delivers another 2 million tons of sulfur compounds into the atmosphere. Together with volcanic gases, sulfur dioxide, hydrogen sulfide, various sulfates and elemental sulfur enter the troposphere;

3) decomposition of nitrogen-containing natural compounds.

Since all protein compounds are based on nitrogen, many processes lead to the formation of nitrogen oxides.

• 4) lightning discharges produce about 8 million tons of nitrogen compounds per year;
• 5) combustion of wood and other biomass.

Anthropogenic acid rain

Here we will talk about the destructive influence of mankind on the state of the planet. A person is used to living in comfort, providing himself with everything necessary, but he is not used to “cleaning up” after himself.

The main cause of acid rain is air pollution. If thirty years ago as global causes, causing the appearance of compounds in the atmosphere that "oxidize" rain, were called industrial enterprises and thermal power plants, today this list has been supplemented by road transport.

Thermal power plants and metallurgical enterprises "give" nature about 255 million tons of sulfur and nitrogen oxides.

Solid-propellant rockets have also made and are making a significant contribution: the launch of one Shuttle complex results in the release of more than 200 tons of hydrogen chloride and about 90 tons of nitrogen oxides into the atmosphere.

Anthropogenic sources of sulfur oxides are enterprises producing sulfuric acid and oil refineries.

Exhaust gases of road transport - 40% of nitrogen oxides entering the atmosphere.

The main source of VOCs in the atmosphere, of course, are chemical industries, oil storage facilities, gas stations and gas stations, as well as various solvents used both in industry and in everyday life.

The final result is as follows: human activity delivers more than 60% of sulfur compounds, about 40-50% of nitrogen compounds and 100% of volatile organic compounds into the atmosphere.

Oxides, getting into the atmosphere, react with water molecules, forming acids. Sulfur oxides, getting into the air, form sulfuric acid, nitrogen oxides - nitric acid. One should also take into account the fact that the atmosphere above large cities always contains particles of iron and manganese, which act as catalysts for reactions. Since there is a water cycle in nature, water in the form of precipitation sooner or later falls on the ground. Along with water, acid also enters.

The term "acid rain" was introduced by the English chemist R.E. Smith over 100 years ago.

In 1911, in Norway, fish deaths were recorded as a result of acidification of natural water. However, only at the end of the 60s, when similar cases in Sweden, Canada, and the USA attracted public attention, the suspicion arose that the cause was rain with a high content of sulfuric acid.

Acid rain is atmospheric precipitation (rain, snow) with a pH less than 5.6 (high acidity).

Acid rains are formed during industrial emissions of sulfur dioxide and nitrogen oxides into the atmosphere, which, when combined with atmospheric moisture, form sulfuric and nitric acids. As a result, rain and snow are acidified (pH value below 5.6). In Bavaria (Germany) in August 1981 it rained with acidity pH = 3.5. The maximum recorded acidity of precipitation in Western Europe- pH = 2.3.

The total global anthropogenic emissions of sulfur and nitrogen oxides are more than 255 million tons annually (1994). Acid-forming gases remain in the atmosphere for a long time and can travel hundreds or even thousands of kilometers. Thus, a significant part of the UK's emissions ends up in northern countries(Sweden, Norway, etc.), i.e. transported across borders and damages their economies.

To solve the problem of acid rain, it is necessary to reduce emissions of sulfur dioxide and nitrogen oxide into the atmosphere. This can be achieved in several ways, including by reducing the energy received by humans from burning fossil fuels and increasing the number of power plants using alternative sources energy (energy of sunlight, wind, tidal energy). Other opportunities to reduce emissions of pollutants into the atmosphere are:

• 1. Reducing the sulfur content in various types fuel. The most acceptable solution would be to use only those fuels that contain minimal amounts of sulfur compounds. However, there are very few such fuels. Only 20% of all world oil reserves have a sulfur content of less than 0.5%. And in the future, unfortunately, the sulfur content of the fuels used will increase, as oil with low sulfur content is being produced at an accelerated pace. The same is true with fossil coals. The removal of sulfur from the fuel composition turned out to be a very expensive process in financial terms, moreover, it is possible to remove no more than 50% of sulfur compounds from the fuel composition, which is an insufficient amount.
• 2. The use of high pipes. This method does not reduce the impact on the environment, but increases the efficiency of mixing pollutants in higher layers of the atmosphere, which leads to acid precipitation in more remote areas from the source of pollution. This method reduces the impact of pollution on local ecosystems, but increases the risk of acid rain in more remote regions.
• 3. Technological changes. The amount of nitrogen oxides NO, which is formed during combustion, depends on the combustion temperature. In the course of the experiments, it was possible to establish that the lower the combustion temperature, the less nitric oxide appears, moreover, the amount of NO depends on the time spent by the fuel in the combustion zone with excess air.

Reductions in sulfur dioxide emissions can be obtained by desulphurizing end gases. The most common method is the wet process, where the final gases are bubbled through a solution of limestone, resulting in the formation of sulfite and calcium sulfate. In this way, it is possible to remove from the final gases the largest number sulfur.

4. Liming. To reduce the acidification of lakes and soils, alkaline substances (CaCO 3) are added to them. This operation is very common in the Scandinavian countries, where lime is sprayed from helicopters onto the soil or into a catchment area. The Scandinavian countries are the most affected by acid rain, as most of the Scandinavian lakes have a granite or limestone-poor bed. Such lakes have a much lower ability to neutralize acids than lakes located in areas rich in limestone. But along with the advantages, liming also has a number of disadvantages:

In the flowing and rapidly mixing water of lakes, neutralization is not effective enough;

There is a gross violation of the chemical and biological balance of waters and soils;

It is not possible to eliminate all the harmful effects of acidification;

Lime cannot be removed heavy metals. During the decrease in acidity, these metals turn into sparingly soluble compounds and precipitate, but when a new portion of the acid is added, they dissolve again, thus representing a constant potential hazard to lakes.

It should be noted that a method has not yet been developed that, when burning fossil fuels, will make it possible to minimize emissions of sulfur dioxide and nitrogen, and in some cases completely prevent it.