Acid rains … This phrase in modern, especially urban life has become commonplace. Summer residents often complain that after such unpleasant rainfall, 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 rains are. These are all known types of precipitation, whose water index (pH) is below normal. The norm is considered to be pH 7. If the study shows an underestimation of this figure in precipitation, they are considered acidic. In conditions of an ever-increasing industrial boom, the acidity of rain, snow, fog and hail is hundreds of times higher than normal.
Causes
Again and again acid rain falls. The reasons lie in the toxic emissions of industrial facilities, car exhaust, to a much lesser extent - in the decay of natural elements. The atmosphere is filled with sulfur and nitrogen oxides, hydrogen chloride and other compounds that form acids. The result is acid rain.
There are precipitation and alkaline content. They note the presence of calcium or ammonia ions. The concept of acid rain also applies to them. This is due to the fact that, falling into a body of water or soil, such precipitation affects the change in water-alkaline balance.
What do acid precipitates lead to
Oxidation of the environment, of course, does not entail anything good. Acid rains are extremely harmful. The reasons for the death of vegetation after such precipitation lies in the fact that many useful elements leach from the earth with acids, in addition, pollution with hazardous metals: aluminum, lead and others, is also observed. Contaminated sediments cause mutations and death of fish in ponds, 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.
After reviewing the general characteristics of this atmospheric phenomenon, we can conclude that the problem of acid rain is one of the most relevant from an environmental point of view.
Scientific research
It is important to dwell in more detail on the scheme of chemical pollution of nature. Acid rain is the cause of many environmental disruptions. Such a characteristic of precipitation appeared in the second half of the 19th century, when a chemist from Great Britain R. Smith revealed the content of hazardous substances in vapors and smoke that greatly change the chemical picture of precipitation. In addition, acid rain is a phenomenon that spreads over vast territories, regardless of the source of pollution. The scientist also noted the destruction that caused the infected sediments: plant diseases, loss of color by tissues, acceleration of the spread of rust, and others.
Experts are more accurate in determining what acid rain is. Indeed, 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.
Anthropogenic impact on nature
Lakes die, the number of fish schools decreases, forests disappear - all these are terrible consequences of the oxidation of nature. Soils in forests do not react so strongly to acidification as water bodies, but plants very negatively perceive all changes in acidity. Like an aerosol, harmful sediment envelops foliage and needles, saturates the trunks, and penetrates the soil. Vegetation receives chemical burns, gradually weakening and losing its ability to survive. Soils lose their fertility and saturate growing crops with toxic compounds.
Biological resources
When a study of lakes in Germany was conducted, it was found that in water bodies, where the water figure deviated significantly from the norm, the fish disappeared. Only in some lakes single specimens were caught.
Historical heritage
The seemingly invulnerable creations of man also suffer from acid precipitation. The ancient Acropolis, located in Greece, is known throughout the world for the outlines of its mighty marble statues. Natural materials have not spared centuries: the noble rock is destroyed by winds and rains, the formation of acid rains activates this process even more. Restoring historical masterpieces, modern masters did not take measures to protect metal compounds from rust. The result was that acid rain, oxidizing iron, caused large cracks in the statues, marble cracked due to rust pressure.
Cultural monuments
The United Nations has initiated studies on the effects of acid precipitation on cultural heritage sites. During them, the negative effects of rain on the most beautiful stained-glass windows of cities in Western Europe were proved. Thousands of colored glasses risk falling into oblivion. Until the twentieth century, they delighted people with their strength and originality, but the last decades, clouded by acid rain, threaten to destroy magnificent stained glass paintings. Dust saturated with sulfur destroys antique objects made of leather and paper. Under the influence of sulfur dioxide, ancient products lose their ability to resist atmospheric phenomena, become brittle and may soon crumble to dust.
Ecological catastrophy
Acid rain is a serious problem for the survival of mankind. Unfortunately, the realities of modern life require an ever greater expansion of industrial production, which increases the volume of toxic emissions into the atmosphere. The population of the planet is increasing, the standard of living is increasing, there are more and more cars, and energy consumption is going through the roof. Moreover, thermal power plants of the Russian Federation alone pollute the environment every year with millions of tons of sulfur-containing anhydride.
Acid Rains and Ozone Holes
Ozone holes are no less common and cause more serious concerns. Explaining the essence of this phenomenon, it must be said that this is not a real gap in the atmospheric envelope, but a violation 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 the harmful radiation of solar ultraviolet radiation, protecting the planet from strong radiation. That is why ozone holes and acid rains are threats to the normal life of the planet, requiring close attention.
Ozone integrity
The beginning of the twentieth century replenished the list of human inventions with chlorofluorocarbons (CFCs). Their feature was exceptional stability, lack of smell, incombustibility, lack of toxic effects. CFCs gradually began to be universally introduced into the production of various refrigeration units (from automobiles to medical complexes), fire extinguishers, and household aerosols.
Only at the end of the second half of the 20th century, chemists Sherwood Roland and Mario Molina suggested that these miraculous substances, also called freons, strongly affect the ozone layer. At the same time, CFCs can soar in the air for decades. Gradually rising from the earth, they reach the stratosphere, where ultraviolet radiation destroys the compounds of freon, releasing chlorine atoms. As a result of this process, ozone is converted to oxygen much faster than under normal environmental conditions.
The scary thing is that it takes only a few chlorine atoms to modify hundreds of thousands of ozone molecules. In addition, chlorofluorocarbons are considered gases that create a greenhouse effect and are involved in the process of global warming. In fairness, it is worth adding that nature itself also makes a contribution to the destruction of the ozone layer. So, volcanic gases contain up to one hundred compounds, including carbon. Natural freons contribute to the active thinning of the ozone layer above the poles of our planet.
