Thermal pollution refers to the phenomena in which heat is released into water bodies or into the atmospheric air. At the same time, the temperature rises much higher than the average norm. Thermal pollution of nature is associated with human activities and greenhouse gas emissions, which are the main cause of global warming.
Sources of thermal pollution of the atmosphere
There are two groups of sources:
- natural - these are forest fires, volcanoes, dust storms, dry winds, processes of decomposition of living and plant organisms;
- anthropogenic are oil and gas processing, industrial activity, thermal power engineering, nuclear energy, transport.
Every year, about 25 billion tons of carbon monoxide, 190 million tons of sulfur oxide, 60 million tons of nitrogen oxide enter the Earth's atmosphere as a result of human activities. Half of all this waste is added as a result of the activities of the energy industry, industry and metallurgy.
Car exhaust emissions have increased in recent years.
Consequences
In metropolitan cities with large industrial enterprises, the atmospheric air experiences the strongest thermal pollution. It receives substances that have a higher temperature than the air layer of the surrounding surface. The temperature of industrial emissions is always higher than the average surface layer of air. For example, during forest fires, from the exhaust pipes of cars, from the pipes of industrial enterprises, when heating houses, streams of warm air with various impurities are released. The temperature of such a stream is approximately 50-60 ºС. This layer raises the average annual temperature in the city by six to seven degrees. "Islands of heat" are formed in and above cities, which leads to an increase in cloudiness, while increasing the amount of precipitation and increasing air humidity. When the products of combustion are added to moist air, moist smog (like London smog) is formed. Ecologists say that over the past 20 years, the average temperature of the troposphere has increased by 0.7º C.
Sources of thermal soil pollution
Sources of thermal soil pollution in large cities and industrial centers are:
- gas pipes of metallurgical enterprises, the temperature reaches 140-150ºС;
- heating mains, temperature around 60-160ºС;
- communication taps, temperature 40-50º C.
Consequences of thermal influence on soil cover
Gas pipes, heating mains and communication outlets increase the soil temperature by several degrees, which is negativeaffects the soil. In winter, this leads to snow melting and, as a result, freezing of the surface layers of the soil, and in summer the reverse process occurs, the top layer of the soil heats up and dries out. The soil cover is closely related to the vegetation and living microorganisms that live in it. A change in its composition negatively affects their life.
Sources of thermal pollution of hydrological facilities
Thermal pollution of water bodies and coastal marine areas occurs as a result of the discharge of wastewater into water bodies by nuclear and thermal power plants, industrial enterprises.
Effects of wastewater discharges
The discharge of sewage leads to an increase in water temperature in reservoirs by 6-7 ºС, the area of such warm spots can reach up to 30-40 km2.
Warm layers of water form a kind of film on the surface of the water mass, which prevents natural water exchange (surface waters do not mix with bottom waters), the amount of oxygen decreases, and the need of organisms for it increases, while the species number of algae increases.
The greatest degree of thermal water pollution is carried out by power plants. Water is used to cool NPP turbines and gas condensate in TPPs. Water used by power plants is heated by about 7-8 ºС, after which it is discharged into nearby water bodies.
The increase in water temperature in reservoirs has a negative impact on living organisms. For each of them there is a temperature optimum at which the population feelsexcellent. In the natural environment, with a slow increase or decrease in temperature, living organisms gradually adapt to changes, but if the temperature rises sharply (for example, with a large volume of effluent discharges from industrial enterprises), then the organisms do not have time to acclimatize. They get heat shock, as a result of which they can die. This is one of the most negative effects of thermal pollution on aquatic life.
But there may be other, more detrimental consequences. For example, the effect of thermal water pollution on metabolism. With an increase in temperature in organisms, the metabolic rate increases, and the need for oxygen increases. But as the water temperature rises, the oxygen content in it decreases. Its deficiency leads to the death of many species of aquatic living organisms. The almost 100% destruction of fish and invertebrates causes the water temperature to rise by several degrees in the summer. When the temperature regime changes, the behavior of fish also changes, natural migration is disrupted, untimely spawning occurs.
Thus, an increase in water temperature can change the species structure of water bodies. Many species of fish either leave these areas or die. Algae characteristic of these places are replaced by heat-loving species.
If, along with warm water, organic and mineral substances (domestic sewage, mineral fertilizers washed from the fields) enter the reservoirs, there is a sharp reproduction of algae, they begin to formdense mass, covering each other. As a result, their death and decay occur, which leads to the pestilence of all living organisms of the reservoir.
The thermal pollution of water bodies by thermal power plants is dangerous. They generate energy using turbines, the exhaust gas must be cooled from time to time. Used water is discharged into reservoirs. At large thermal power plants, this amount reaches 90 m3. This means that a continuous warm flow enters the reservoir.
Damage from pollution of aquatic ecosystems
All the consequences of thermal pollution of water bodies cause catastrophic harm to living organisms and change the habitat of the person himself. Damage caused by pollution:
- aesthetic (the appearance of landscapes is broken);
- economic (remediation of pollution, extinction of many fish species);
- ecological (species of aquatic vegetation and living organisms are destroyed).
The volume of warm water discharged by power plants is constantly growing, therefore, the temperature of water bodies will also rise. In many rivers, according to environmentalists, it will increase by 3-4 °C. This process is already underway. For example, in some rivers in America, water overheating is about 10-15 °С, in England - 7-10 °С, in France - 5 °С.
Thermal pollution
Thermal pollution (thermal physical pollution) is a form that occurs as a result of an increase in ambient temperature. Its causes are industrial and military emissions of heated air, large fires.
Thermal pollution of the environment is associated with the work of enterprises of the chemical, pulp and paper, metallurgical, woodworking industries, thermal power plants and nuclear power plants, which require large volumes of water to cool equipment.
Transport is a powerful pollutant of the environment. About 80% of all annual emissions come from cars. Many harmful substances are dispersed over considerable distances from the source of pollution.
When gas is burned at thermal power plants, in addition to chemical effects on the atmosphere, thermal pollution also occurs. In addition, within a radius of about 4 km from the torch, many plants are in a depressed state, and within a radius of 100 meters, the vegetation cover is dying.
Every year, about 80 million tons of various industrial and domestic wastes are generated in Russia, which are a source of pollution of soil cover, vegetation, ground and surface waters, and atmospheric air. In addition, they are a source of radiation and thermal pollution of natural objects.
Land waters are polluted with a variety of chemical wastes that get there when mineral fertilizers, pesticides are washed off the soil, with sewage and industrial effluents. Thermal and bacterial pollution occurs in reservoirs, many species of plants and animals die.
Any release of heat into the natural environment leads to a change in the temperature of its components, the lower layers of the atmosphere are especially affected,soil and hydrosphere objects.
According to environmentalists, thermal emissions into the environment are not yet able to affect the balance of the planet, but they have a significant impact on a specific area. For example, the air temperature in large cities is usually somewhat higher than outside the city; the thermal regime of rivers or lakes changes when wastewater from thermal power plants is discharged into them. The species composition of the inhabitants of these spaces is changing. For each species there is a temperature interval in which the species is able to adapt. For example, trout can survive in warm water but cannot reproduce.
Thus, thermal discharges also affect the biosphere, although this is not on a planetary scale, but is also noticeable for humans.
Temperature pollution of the soil cover is fraught with the fact that there is a close interaction with animals, vegetation and microbial organisms. With an increase in soil temperature, the vegetation cover changes to more thermophilic species, many microorganisms die, unable to adapt to new conditions.
Thermal pollution of groundwater occurs as a result of runoff entering aquifers. This negatively affects the quality of water, its chemical composition, and thermal conditions.
Thermal pollution of the environment worsens the conditions of life and human activity. In cities, with elevated temperatures combined with high humidity, people experience frequent headaches, general malaise, horse racing.blood pressure. High humidity leads to corrosion of metals, damage to sewers, heat pipes, gas pipes, and so on.
Consequences of environmental pollution
You can specify all the consequences of thermal pollution of the environment and highlight the main problems that need to be addressed:
1. Heat islands form in major cities.
2. Smog is formed, air humidity increases and permanent cloudiness forms in megacities.
3. Problems arise in rivers, lakes and coastal areas of the seas and oceans. Due to the increase in temperature, the ecological balance is disturbed, many species of fish and aquatic plants are dying.
4. The chemical and physical properties of water change. It becomes unusable even after cleaning.
5. Living organisms of water bodies are dying or are in a depressed state.
6. Groundwater temperatures are rising.
7. The structure of the soil and its composition are disturbed, the vegetation and microorganisms living in it are suppressed or destroyed.
Thermal pollution. Prevention and measures to prevent it
The main measure to prevent thermal pollution of the environment is the gradual abandonment of the use of fuel, a complete transition to alternative renewable energy: solar, wind and hydropower.
To protect water areas from thermal pollution in the turbine cooling system, it is necessary to build reservoirs - coolers, from which water after coolingcan be used again in the cooling system.
In recent decades, engineers have been trying to eliminate the steam turbine in thermal power plants, using the magnetohydrodynamic method of converting thermal energy into electrical energy. This significantly reduces thermal pollution of the surrounding area and water bodies.
Biologists seek to identify the limits of stability of the biosphere as a whole and individual species of living organisms, as well as the limits of equilibrium of biological systems.
Environmentalists, in turn, study the degree of influence of human economic activity on natural processes in the environment and seek to find ways to prevent a negative impact.
Protect the environment from thermal pollution
It is customary to divide thermal pollution into planetary and local. On a planetary scale, pollution is not very large and amounts to only 0.018% of the solar radiation entering the planet, that is, within one percent. But, thermal pollution has a strong impact on nature at the local level. To regulate this influence in most industrialized countries, limits (limits) of thermal pollution have been introduced.
As a rule, the limit is set for the regime of water bodies, since it is the seas, lakes and rivers that suffer to a large extent from thermal pollution and receive its main part.
In European countries, water bodies should not warm up by more than 3 °C from their natural temperature.
In the United States, in rivers, water heating should not be whiter than 3 °С, in lakes - 1.6 °С, in the waters of the seas and oceans - 0.8 °С.
BIn Russia, the water temperature in reservoirs should not rise by more than 3 °C compared to the average temperature of the hottest month. In reservoirs inhabited by salmon and other cold-loving species of fish, the temperature cannot be increased by more than 5 °C, in summer no higher than 20 °C, in winter - 5 °C.
The scale of thermal pollution near large industrial centers is quite significant. So, for example, from an industrial center with a population of 2 million people, from a nuclear power plant and an oil refinery, thermal pollution spreads 120 km away and 1 km in height.
Environmentalists suggest using heat waste for household needs, for example:
- for irrigation of agricultural land;
- in the greenhouse industry;
- to maintain the northern waters in an ice-free state;
- for the distillation of heavy products of the oil industry and fuel oil;
- for breeding heat-loving fish species;
- for the construction of artificial ponds heated in winter for wild waterfowl.
On a planetary scale, thermal pollution of the natural environment indirectly affects global warming. Greenhouse gas emissions from industries do not directly increase temperatures, but increase them through the greenhouse effect.
To solve environmental problems and prevent them in the future, humanity must solve a number of global problems and direct all efforts to reduce air pollution, thermalpollution of the planet.
