Acid phrases have become commonplace in modern life, especially in urban life. Summer residents often complain that after such unpleasant precipitation, plants begin to wither, and a whitish or yellowish coating appears in puddles.
What it is
Science has a definite answer to the question of what acid rain is. These are all known whose water levels are below normal. The norm is considered to be pH 7. If the study shows an underestimation of this figure in precipitation, it is considered acidic. In conditions of an ever-growing industrial boom, the acidity of rain, snow, fog and hail is hundreds of times higher than normal.
Causes
Acid rain falls again and again. The reasons lie in toxic emissions industrial facilities, car exhaust gases, and to a much lesser extent in the decay of natural elements. The atmosphere is filled with sulfur and nitrogen oxides, hydrogen chloride and other acid-forming compounds. The result is acid rain.
There are precipitations with alkaline content. They contain calcium or ammonia ions. The concept of “acid rain” also applies to them. This is explained by the fact that, when such precipitation enters a reservoir or soil, it affects the change in the water-alkaline balance.
What does acid precipitation cause?
No good oxidation surrounding nature, of course, does not entail. Acid rain is extremely harmful. The reasons for the death of vegetation after such precipitation lie in the fact that many useful elements are leached from the earth by acids, in addition, there is also contamination with hazardous metals: aluminum, lead and others. Contaminated sediments cause mutations and death of fish in water bodies, and improper development of vegetation in rivers and lakes. They also have a detrimental effect on the normal environment: they significantly contribute to the destruction of natural facing materials and cause accelerated corrosion of metal structures.
Having become familiar with general characteristic given atmospheric phenomenon, we can conclude that the problem acid rain is one of the most relevant from an environmental point of view.
Scientific research
It is important to take a closer look at the scheme of chemical pollution of nature. Acid rain is the cause of many environmental disturbances. This characteristic of precipitation appeared in the second half of the 19th century, when the British chemist R. Smith discovered the content of vapor and smoke hazardous substances, which greatly change the chemical picture of precipitation. In addition, acid rain is a phenomenon that spreads over vast areas, regardless of the source of pollution. The scientist also noted the destruction that contaminated sediments entailed: plant diseases, loss of color in tissues, accelerated spread of rust, and others.
Experts are more precise in defining what acid rain is. After all, in reality it is snow, fog, clouds and hail. Dry precipitation with a lack of atmospheric moisture falls in the form of dust and gas.
on nature
Lakes are dying, the number of fish schools is decreasing, forests are disappearing - all these are terrible consequences of the acidification of nature. Soils in forests do not react as sharply to acidification as water bodies, but plants react very negatively to all changes in acidity. Like an aerosol, harmful precipitation envelops foliage and pine needles, saturates trunks, and penetrates the soil. Vegetation receives chemical burns, gradually weakening and losing the ability to survive. Soils lose fertility and saturate growing crops with toxic compounds.
Biological resources
When a study of lakes in Germany was carried out, it was found that in reservoirs where the water indicator deviated significantly from the norm, the fish disappeared. Only in some lakes were single specimens caught.
Historical heritage
Seemingly invulnerable human creations also suffer from acid precipitation. The ancient Acropolis, located in Greece, is famous throughout the world for the outlines of its mighty marble statues. The centuries are not kind natural materials: noble rock is destroyed by winds and rains, the formation of acid rain further intensifies this process. When restoring historical masterpieces, modern masters did not take measures to protect metal joints from rust. The result is that acid rain, oxidizing iron, causes large cracks in statues, marble cracks due to the pressure of rust.
Cultural monuments
The United Nations has initiated research into the impact of acid precipitation on objects cultural heritage. During them it was proven negative consequences the effects of rain on the most beautiful stained glass windows of Western European cities. Thousands of colored glasses are at risk of falling into oblivion. Until the twentieth century, they delighted people with their durability and uniqueness, but last decades, marred by acid rain, threaten to destroy the magnificent stained glass paintings. Dust saturated with sulfur destroys antique items made of leather and paper. Ancient products under the influence lose their ability to resist atmospheric phenomena, become fragile and may soon crumble into dust.
Ecological catastrophy
Acid rain is serious problem for the survival of humanity. Unfortunately, the reality modern life require more and more expansion industrial production, which increases the volume of toxic The population of the planet is increasing, the standard of living is rising, there are more and more cars, energy consumption is going through the roof. At the same time, only thermal power plants Russian Federation Every year they pollute the environment with millions of tons of anhydride containing sulfur.
Acid rain and ozone holes
Ozone holes are just as common and a more serious concern. Explaining the essence of this phenomenon, it must be said that this is not a real rupture of the atmospheric shell, but a disturbance in the thickness of the ozone layer, which is located approximately 8-15 km from the Earth and extends into the stratosphere up to 50 km. The accumulation of ozone largely absorbs harmful solar ultraviolet radiation, protecting the planet from extreme radiation. That is why ozone holes and acid rain are threats to the normal life of the planet that require the closest attention.
Integrity of the ozone layer
The beginning of the twentieth century added chlorofluorocarbons (CFCs) to the list of human inventions. Their features were exceptional stability, lack of odor, non-flammability, and lack of toxic influence. CFCs gradually began to be introduced everywhere into the production of various cooling units (from cars to medical complexes), fire extinguishers, and household aerosols.
Only towards the end of the second half of the twentieth century, chemists Sherwood Roland and Mario Molina suggested that these miracle substances, otherwise called freons, had a strong effect on the ozone layer. At the same time, CFCs can “hover” in the air for decades. Gradually rising from the ground, they reach the stratosphere, where ultraviolet radiation destroys freon compounds, releasing chlorine atoms. As a result of this process, ozone is converted into oxygen much faster than under normal natural conditions.
The scary thing is that it only takes a few chlorine atoms to modify hundreds of thousands of ozone molecules. In addition, chlorofluorocarbons are considered to be gases that create Greenhouse effect and those involved in the process global warming. To be fair, it is worth adding that nature itself also contributes to the destruction of the ozone layer. Thus, volcanic gases contain up to one hundred compounds, including carbons. Natural freons contribute to the active thinning of the ozone-containing layer above the poles of our planet.
What can you do?
Finding out what the dangers of acid rain are is no longer relevant. Now, measures to ensure the cleanliness of the surrounding air should be on the agenda in every state, at every industrial enterprise.
In Russia, giant factories such as RUSAL, in last years They began to approach this issue very responsibly. They spare no expense in installing modern, reliable filters and treatment facilities that prevent oxides and heavy metals from entering the atmosphere.
They are increasingly being used alternative ways obtaining energy that does not entail dangerous consequences. Wind and solar energy (for example, in everyday life and for cars) is no longer science fiction, but a successful practice that helps reduce the volume of harmful emissions.
Expansion of forest plantations, cleaning of rivers and lakes, proper recycling garbage - all this effective methods in the fight against environmental pollution.
Even as a child, I heard that acid rain is extremely dangerous for the environment, but at that time I did not think anything of it. great importance. I thought it was a normal type of rain. Only as you get older do you realize that acid rain is the result of air pollution.
What is acid rain?
Acid rain consists of water droplets that are unusually acidic due to air pollution, primarily containing excessive amounts of sulfur and nitrogen released by cars and industrial plants. Acid rain is also called acid deposition, as this term includes other forms of acid precipitation such as snow.
Causes of acid rain
Human activity is the main cause of acid rain. Over the past few decades, people have released so many different chemical substances that they changed the mixture of gases in the atmosphere. Power plants emit the majority of sulfur dioxide and most nitrogen oxides when they burn fossil fuels.
Why is acid precipitation dangerous?
Acid rain is dangerous for all living and nonliving things, they entail:
- Consequences for the air. Some components of acid pollution are sulfates, nitrates, ozone and hydrocarbon compounds.
- Implications for architecture. Acidic particles also deposit on buildings and statues, causing corrosion.
- Implications for materials. Acid rain destroys all materials and fabrics.
- Consequences for people. Some of the most serious effects of acid rain on people are breathing problems.
- Consequences for trees and soils. Nutrients from the soil are neutralized. And the trees are destined to die, deprived of vital nutrients.
- Consequences for lakes and aquatic ecosystems. Acid rain leads to a sharp change in the pH of water bodies.
Acid rain - terrible phenomenon, which should never be underestimated. If possible, protect your head with an umbrella or hat - this is a minimum precaution.
Causes of acid rain
The main cause of acid rain— presence in the atmosphere due to industrial emissions of sulfur and nitrogen oxides, hydrogen chloride and other acid-forming compounds. As a result, rain and snow become acidified. The formation of acid rain and its impact on the environment is shown in Fig. 1 and 2.
The presence in the air of noticeable quantities, for example, of ammonia or calcium ions, leads to the formation of alkaline rather than acidic precipitation. However, they are also commonly called acidic, since when they enter the soil or water body they change their acidity.
Maximum recorded precipitation acidity in Western Europe- with pH = 2.3, in China - with pH = 2.25. By teaching aid At the experimental base of the Ecological Center of the Russian Academy of Sciences in the Moscow region in 1990, rain with pH = 2.15 was recorded.
Acidification natural environment negatively affects the condition. In this case, not only nutrients are leached from the soil, but also toxic metals, such as lead, aluminum, etc.
The solubility of aluminum increases in acidified water. In lakes, this leads to illness and death of fish, slowing down the development of phytoplankton and algae. Acid rain destroys facing materials (marble, limestone, etc.) and significantly reduces the service life of reinforced concrete structures.
Thus, oxidation of the natural environment- one of the most important environmental problems, requiring a solution in the near future.
Rice. 1. Formation of acid rain and its impact on the environment
Rice. 2. Approximate acidity of rainwater and some substances in pH units
Acid precipitation problem
The development of industry, transport, and the development of new energy sources lead to the fact that the amount of industrial emissions is constantly increasing. This is mainly due to the use of fossil fuels in thermal power plants, industrial enterprises, in car engines and in heating systems of residential buildings.
As a result of the combustion of fossil fuels, compounds of nitrogen, sulfur, chlorine, and other elements enter the Earth's atmosphere. Among them, oxides of sulfur - S0 2 and nitrogen - NO x (N 2 0, N0 2) predominate. Combining with water particles, sulfur and nitrogen oxides form sulfuric (H 2 SO 4) and nitric (HNO 3) acids of varying concentrations.
In 1883, the Swedish scientist S. Arrhenius coined two terms - “acid” and “base”. He called acids substances that, when dissolved in water, form free positively charged hydrogen ions (H +), and bases - substances that, when dissolved in water, form free negatively charged hydroxide ions (OH -).
Aqueous solutions can have a pH (a measure of the acidity of water, or a measure of the degree of concentration of hydrogen ions) from 0 to 14. Neutral solutions have a pH of 7.0, acidic environment characterized by pH values less than 7.0, alkaline - more than 7.0 (Fig. 3).
In an environment with a pH of 6.0, fish species such as salmon, trout, roach and freshwater shrimp. At pH 5.5, pubic bacteria die, which decompose organic matter both leaves and organic debris begin to accumulate at the bottom. Then the plankton die - tiny unicellular algae and the simplest invertebrates that form the basis the food chain reservoir When acidity reaches pH 4.5, all fish, most frogs and insects die, and only some species of freshwater invertebrates survive.
Rice. 3. Acidity scale (pH)
It has been established that the share of man-made emissions associated with the combustion of fossil coal accounts for about 60-70% of them total number, the share of petroleum products is 20-30%, the rest production processes- 10 %. 40% of NOx emissions come from vehicle exhaust.
Consequences of acid rain
Characterized by a strongly acidic reaction (usually pH<5,6), получили название кислотных (кислых) дождей. Впервые этот термин был введен британским химиком Р.Э. Смитом в 1872 г. Занимаясь вопросами загрязнения г. Манчестера, Смит доказал, что дым и пары содержат вещества, вызывающие серьезные изменения в химическом составе дождя, и что эти изменения можно заметить не только вблизи источника их выделения, но и на большом расстоянии от него. Он также обнаружил некоторые вредные effects of acid rain: discoloration of fabrics, corrosion of metal surfaces, destruction of building materials and death of vegetation.
Experts say the term “acid rain” is not accurate enough. For this type of pollutant, the expression “ acid precipitation" Indeed, pollutants can fall not only in the form of rain, but also in the form of snow, clouds, fog (“wet precipitation”), and in the form of gas and dust (“dry precipitation”) during dry periods.
Although the alarm sounded more than a century ago, industrial nations have long ignored the dangers of acid rain. But in the 60s. XX century ecologists reported a decrease in fish schools and even their complete disappearance in some lakes in Scandinavia. In 1972, the problem of acid rain was first raised by Swedish environmental scientists at the UN Environment Conference. Since that time, the danger of global environmental acidification has become one of the most pressing problems facing humanity.
As of 1985, fisheries in 2,500 lakes in Sweden were seriously affected by acid rain. In 1,750 of Southern Norway's 5,000 lakes, fish have completely disappeared. A study of water bodies in Bavaria (Germany) showed that in recent years there has been a sharp decline in the number, and in some cases, the complete disappearance of fish. When studying 17 lakes in the autumn, it was found that the pH of the water ranged from 4.4 to 7.0. In lakes where the pH was 4.4; 5.1 and 5.8, not a single fish was caught, and in the remaining lakes only isolated specimens of lake and rainbow trout and char were found.
Along with the death of lakes, forest degradation occurs. Although forest soils are less susceptible to acidification than bodies of water, the vegetation growing on them reacts extremely negatively to increased acidity. Acid precipitation in the form of aerosols envelops the needles and foliage of trees, penetrates the crown, flows down the trunk, and accumulates in the soil. Direct damage is expressed in chemical burns of plants, decreased growth, and changes in the composition of subcanopy vegetation.
Acid precipitation destroys buildings, pipelines, disables cars, reduces soil fertility and can allow toxic metals to leak into aquifers.
Many world cultural monuments are exposed to the destructive effects of acid precipitation. Thus, over 25 centuries, the marble statues of the world-famous architectural monument of Ancient Greece, the Acropolis, were constantly exposed to wind erosion and rain. Recently, acid precipitation has accelerated this process. In addition, this is accompanied by the deposition of a crust of soot on the monuments in the form of sulfur dioxide emitted by industrial enterprises. To connect individual architectural elements, the ancient Greeks used small iron rods and brackets coated with a thin layer of lead. Thus they were protected from rust. During the restoration work (1896-1933), steel parts were used without any precautions, and due to the oxidation of iron under the influence of acid solutions, extensive cracks formed in the marble structures. Rust causes the volume to increase and the marble to crack.
The results of studies conducted at the initiative of one of the UN commissions indicate that acid precipitation also has a detrimental effect on ancient stained glass in some cities of Western Europe, which can completely destroy them. More than 100,000 samples of colored glass are at risk. Antique stained glass windows were in good condition until the beginning of the 20th century. However, over the past 30 years, the process of destruction has accelerated, and if the necessary restoration work is not carried out, the stained glass windows may die in a few decades. Colored glass made in the 8th-17th centuries is especially at risk. This is explained by the peculiarities of production technology.
Everyone knows what water is. There is a huge amount of it on Earth - one and a half billion cubic kilometers.
If you imagine the Leningrad region as the bottom of a giant glass and try to fit all the Earth’s water into it, then its height should be greater than the distance from the Earth to the Moon. It would seem that there is so much water that there should always be enough of it. But the trouble is that all oceans have salty water. We, and almost all living things, need fresh water. But there isn't much of it. That's why we desalinate water.
Fresh water from rivers and lakes contains a lot of soluble substances, including toxic ones; it may contain pathogenic microbes, so it cannot be used, much less drunk, without additional purification. When it rains, drops of water (or snowflakes when it snows) capture harmful impurities from the air that have entered it from the pipes of some factory.
As a result, harmful, so-called acid rain falls in some places on Earth. Neither plants nor animals like it.
The beneficial drops of rain have always brought joy to people, but now in many areas of the planet, rain has turned into a serious danger.
Acid precipitation (rain, fog, snow) is precipitation whose acidity is higher than normal. A measure of acidity is the pH value (hydrogen index). The pH scale goes from 02 (extremely acidic), through 7 (neutral) to 14 (alkaline), with the neutral point (pure water) having pH=7. Rainwater in clean air has a pH of 5.6. The lower the pH value, the higher the acidity. If the acidity of the water is below 5.5, then the precipitation is considered acidic. Over vast areas of the industrialized countries of the world, precipitation falls, the acidity of which exceeds normal by 10 - 1000 times (pH = 5-2.5).
Chemical analysis of acid precipitation shows the presence of sulfuric (H 2 SO 4) and nitric (HNO 3) acids. The presence of sulfur and nitrogen in these formulas indicates that the problem is related to the release of these elements into the atmosphere. When fuel is burned, sulfur dioxide is released into the air, and atmospheric nitrogen also reacts with atmospheric oxygen to form nitrogen oxides.
These gaseous products (sulfur dioxide and nitrogen oxide) react with atmospheric water to form acids (nitric and sulfuric).
In aquatic ecosystems, acid precipitation causes the death of fish and other aquatic life. Acidification of river and lake water also seriously affects land animals, since many animals and birds are part of food chains that begin in aquatic ecosystems.
Along with the death of lakes, forest degradation also becomes apparent. Acids destroy the protective waxy coating of leaves, making plants more vulnerable to insects, fungi and other pathogens. During drought, more moisture evaporates through damaged leaves.
The leaching of nutrients from the soil and the release of toxic elements contribute to the slowdown of tree growth and death. One can imagine what happens to wild animal species when forests die.
If the forest ecosystem is destroyed, soil erosion begins, clogging of water bodies, flooding and deterioration of water supplies become catastrophic.
As a result of acidification in the soil, nutrients vital to plants are dissolved; These substances are carried by rain into groundwater. At the same time, heavy metals are leached from the soil, which are then absorbed by plants, causing serious damage to them. Using such plants for food, a person also receives an increased dose of heavy metals with them.
When the soil fauna degrades, yields decrease, the quality of agricultural products deteriorates, and this, as we know, entails deterioration in public health.
When exposed to acids, rocks and minerals release aluminum, as well as mercury and lead. which then end up in surface and groundwater. Aluminum can cause Alzheimer's disease, a type of premature aging. Heavy metals found in natural waters negatively affect the kidneys, liver, and central nervous system, causing various cancers. The genetic effects of heavy metal poisoning can take 20 years or more to appear, not only in those who drink dirty water, but also in their descendants.
Acid rain corrodes metals, paints, synthetic compounds, and destroys architectural monuments.
Acid rain is most common in industrialized countries with highly developed energy systems. Over the course of a year, thermal power plants in Russia emit about 18 million tons of sulfur dioxide into the atmosphere, and in addition, thanks to western air transport, sulfur compounds come from Ukraine and Western Europe.
To combat acid rain, efforts must be directed toward reducing emissions of acid-forming substances from coal-fired power plants. And for this you need:
using low-sulfur coal or removing sulfur from it
installation of filters for purification of gaseous products
use of alternative energy sources
Most people remain indifferent to the problem of acid rain. Are you going to wait indifferently for the destruction of the biosphere or are you going to take action?
Acid precipitation (rain) is one of the terms that arose as a result of industrialization.
Air pollution and acid precipitation
Today there is a rapid development of industry: the consumption of the planet's resources, the burning of fuel, as well as the development of environmentally flawed technologies. This in turn leads to water and land. One such manifestation is acid precipitation.
The concept of acid rain was first mentioned in 1872, but acquired its relevance only in the second half of the last century. At the moment, acid precipitation is a serious problem for many countries of the world (almost all European countries and the USA). Ecologists have developed a rain map that clearly shows areas that have a high risk of dangerous precipitation.
Rainwater is characterized by a certain level of acidity. Under normal conditions, this index should correspond to a neutral pH level (from 5.6 - 5.7 and much higher). Slight acidity is the result of However, it is so low that it is not capable of causing harm to living organisms. It turns out that the causes of acid precipitation are related to human activity; natural factors cannot explain this.
The occurrence of acid precipitation
Acid sludge is formed as a result of emissions of large amounts of nitrogen oxides and
The sources of such pollution are thermal power plants, metallurgical production and automobiles. Purification technology has a very low level of development, which does not allow filtering nitrogen and sulfur compounds resulting from the combustion of peat, coal and other types of raw materials used in industry. Once in the atmosphere, the oxides combine with water as a result of reactions under the influence of sunlight. After this, they fall as rain and are called “acid precipitation.”
Consequences of acid precipitation
Scientists say that acid precipitation is very dangerous for plants, people and animals. The following are the most important dangers:
Such rains significantly increase the acidity of all bodies of water, be it a river, pond or reservoir. As a result, the extinction of natural fauna and flora is observed. The ecosystem of reservoirs is changing, they become clogged, swamped, and silt increases. After such changes, the water is unsuitable for human use. It increases the amount of heavy metal salts and various toxic mixtures that are absorbed by the microflora of the reservoir under normal conditions.
These rains are a consequence of plant extinction and forest degradation. Coniferous trees suffer the most. The fact is that their leaves renew themselves very slowly, and this does not give them the opportunity to recover on their own after acid rain. Young forests are also susceptible to this process, and their quality is rapidly declining. Excessive sediment mass leads to the destruction of forests.
In Europe and the USA, acid rain is the main cause of poor harvests, as well as the extinction of crops in the fields. The cause of the damage lies not only in the constant exposure to rain, but also in disturbances in the mineralization of the soil.
Architectural monuments, various buildings and structures also suffer from acid rain. As a result of this phenomenon, the corrosion process is significantly accelerated and the mechanisms fail.
In some cases, acid rain can cause irreparable harm to humans and animals. When they are in high-risk areas, they begin to worry about diseases of the upper respiratory tract. If this continues, then nitrate and black acid of excessively high concentrations will soon fall out. At the same time, the threat to human life increases significantly.
Fighting acid rain
Of course, you can’t go against nature - it’s unrealistic to fight precipitation itself. Falling out over fields and other large areas, acid precipitation causes irreparable harm, and there is no reasonable solution to this problem. It is a completely different matter when it is necessary to eliminate not their consequences, but the causes of their occurrence. To avoid the formation of acid rain, you need to constantly follow a number of rules: environmentally friendly and safe road transport, special cleaning technologies, new production technologies, alternative sources of energy production, etc.
Humanity has stopped. We all use the limitless resources of our planet, pollute it and do not want to accept the consequences. But it was human activity that led the Earth to this state. This is very dangerous, because if we do not start taking care of our planet, the consequences will become catastrophic.
Loading...
