Technogenic environmental pollution

All parts of the biosphere (atmosphere, hydrosphere, lithosphere) are actively polluted by various substances and their compounds.

Atmosphere. This is a mixture of gases that do not interact under normal natural conditions. The composition of the atmosphere at the Earth's surface (up to altitudes of about 50 km) remains constant: nitrogen - 78.08%, oxygen - 20.95%, argon - 0.9%, and in small fractions of a percent - carbon dioxide, helium and other gases. Ozone (2...7)10~ b% occupies a special place among small impurities. It strongly absorbs ultraviolet radiation from the Sun, which has great biological activity and, at high intensities, has a detrimental effect on organic life as a whole. The bulk of ozone is concentrated in the atmospheric layer of 15 -55 km with a maximum concentration at altitudes of 20 - 25 km.

The standard chemical composition of the atmosphere is always superimposed on a certain amount of impurities of natural origin. Impurities emitted from natural sources include:

dust (volcanic, plant, cosmic origin; released during weathering of soil and rocks; particles of sea salt entering the air masses during rough seas and oceans). For example, during the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury enter the atmosphere annually;

smoke and gases from forest and steppe fires, gases of volcanic origin;

products of plant and animal origin.

All these sources are spontaneous, short-term in nature and spatially distributed locally.

The level of atmospheric pollution with natural impurities is background for it (“chemical background”) and changes little over time.

The state and composition of the atmosphere largely determine the intensity of solar radiation on the Earth's surface. The shielding role of the atmosphere in the process of transferring thermal energy from the Sun to the Earth and from the Earth to Space affects the average temperature of the biosphere, which is about +15°C.

The bulk of solar radiation is transmitted to the Earth's surface as visible radiation and reflected from the Earth's surface in the form of infrared (thermal) radiation. Therefore, the proportion of reflected radiant energy absorbed by the atmosphere depends on its gas composition and dust content in it. The greater the concentration of impurity gases and dust, the less reflected solar radiation goes into outer space and the more thermal energy remains in the atmosphere (greenhouse effect).

As calculations and measurements show, an increase in the concentration of carbon dioxide in the Earth’s atmosphere leads to a slight increase in temperature at its surface: by +0.05, +0.17 and +0.46 °C, respectively.

specifically in 1978, 2000 and 2025, which significantly affects climate change.

The main air pollutants are motor transport, metallurgy, heat and power engineering, chemical industry, and construction materials production enterprises, which account for 30, 26, 25, 8 and 6% of emissions, respectively.

Thus, only when burning hydrocarbon fuels, about 400 million tons of sulfur dioxide and nitrogen oxides are released into the planet’s atmosphere annually (or 70 kg for each inhabitant of the Earth). It should be taken into account that humanity’s energy needs are growing at a rate of 3–4% per year, i.e. double every 20 -30 years.

Increasing chemical pollution of the air in large cities can be considered an environmental emergency. Thus, with an average annual mileage of a passenger car of about 15,000 km, it consumes about 4,350 kg of oxygen and emits 3,250 kg of carbon dioxide, 530 kg of carbon monoxide and about 1 kg of lead into the atmosphere.

We list the most common substances that pollute the atmosphere: sulfur dioxide (SO 2) - 17.5%, carbon oxides (CO, CO 2) - 15%, nitrogen oxides (NO, NO 2) - 14.5%, solid impurities (dust , soot) - 14.5%.

It has been established that dust is emitted into the atmosphere annually, million tons: when burning coal - 93.6, during cement production - 53.4, by metallurgical enterprises - 26.7.

Most of the atmospheric air impurities in cities penetrate into residential and other premises. In the summer (with the windows open), the composition of the air in the room corresponds to atmospheric by 90%, in winter - by 50%.

Freons, gases or volatile liquids containing fluorine and chlorine, have a significant impact on the ozone layer. The duration of their “life” in the atmosphere is about 100 years, as a result of which impurities accumulate in the ozone layer. Sources of freons: refrigeration units when the tightness of the thermal circuit is broken, household cans for spraying various substances, etc.

As a result of technogenic impact on the atmosphere, the following are possible:

exceeding permissible concentrations of harmful impurities in cities and towns;

formation of smog and acid rain;

the emergence of the greenhouse effect, which contributes to an increase in the average temperature of the Earth's surface.

Hydrosphere. Almost three-quarters of the earth is covered with water. Depending on the salt concentration, natural waters are divided into fresh (salt concentration no more than 1 g/l) and sea water.

cues. Fresh water accounts for about 3% of the total water mass, with 2% contained in inaccessible ice.

River and lake waters are most convenient for use. As a rule, they are mineralized to one degree or another, mainly due to the salts of calcium, magnesium, etc. soluble in them.

Sea water has the same chemical composition throughout the World Ocean. The average salt concentration in it is

3.5%, and unlike fresh water, salts are mainly represented by chlorides.

A characteristic feature of technogenic pollution of the natural environment is the entry into it from the technosphere of gaseous, aerosol, solid and liquid pollutants that are unusual for it.

The main pollutants of the hydrosphere: domestic and industrial wastewater from municipal facilities, food, medical, pulp and paper industries; agriculture (near Uz, fertilizers applied to the soil are washed into rivers and lakes); maritime transport (primarily oil from tankers - about 0.1% of annual oil transportation ends up at sea).

Every year, 26.5 million tons of petroleum products (which is approximately 1% of their production), 0.46 million tons of phenols, 5.5 million tons of synthetic fiber production waste, and 0.17 million tons of plant organic residues enter the hydrosphere from the global runoff.

The impact of the technosphere on the hydrosphere leads to the following negative consequences:

The supply of drinking water with acceptable levels of impurities is decreasing;

the state and development of the flora and fauna of the oceans, seas, rivers and lakes changes;

the natural cycle of many substances in the biosphere is disrupted.

Land pollution is caused primarily by agricultural production (fertilizers and pesticides). It can lead to:

to a reduction in arable land and a decrease in its fertility;

saturation of plants with harmful substances, which inevitably leads to food contamination (currently up to 70% of the harmful effects on humans come from food products);

disruption of the balance of ecosystems due to the death of insects, birds, animals, and some plant species.

In a specific area, air pollution, and subsequently water and soil pollution, is formed due to the following three components:

global, due to the presence on Earth of numerous sources of industrial pollution and their transboundary transport over long distances;

regional, related to emissions in a given industrial region;

local (local), caused by emissions of a specific object in a given area.

During long-distance transport, the speed of propagation of air masses is usually hundreds of kilometers per day. Therefore, only those chemicals whose lifetime in the atmosphere exceeds 12 hours can spread over long distances. For a noticeable accumulation of harmful substances (coming from the atmosphere) in soil and water, their lifetime in these environments must be at least a year. Long-lived impurities include CO 2, freons and a number of others. Sulfur and nitrogen oxides have a lifetime of about ten days or less.

To ensure environmental safety requirements, the content of the entire range of chemical substances entering the environment is strictly regulated. For these purposes, two main quantitative indicators are used:

maximum permissible concentration (MPC);

maximum permissible emission (MPE).

Maximum permissible concentration - the maximum concentration (mass of an impurity (g) per unit volume (l) of air, water or mass (kg) of soil), which does not have a direct or indirect harmful effect on a person, his offspring and sanitary living conditions. Currently, maximum permissible concentrations have been established for the average person for the air environment of enterprises, the atmosphere of cities and other populated areas, and for the water of open reservoirs. Maximum concentration limits have been established in soils for the content of pesticides, heavy metals, and organic compounds. The average daily MPC is averaged over a long period of time, up to a year. The indicated maximum permissible concentrations are calculated taking into account the global and regional components of the technogenic chemical background.

Depending on the maximum permissible concentration standards, water sources are divided into two categories: sources for household and drinking purposes, including for water supply to food industry enterprises, and reservoirs within populated areas, as well as for swimming, sports, and recreation.

Hygienic requirements for domestic drinking water, fishery water sources, as well as requirements for drinking water are regulated by relevant standards and sanitary norms.

In order to practically control the flow of harmful substances into the environment from an emission source, the maximum permissible concentrations for harmful substances are calculated based on the established maximum permissible concentrations. The maximum permissible limit is established for each stationary and mobile source by the relevant regulatory documents (for example, “Sanitary standards for the design of industrial enterprises” SN-245-71).

The rapid growth of the world's population, industrial and agricultural production is accompanied by a sharp increase in organic and inorganic industrial waste and consumer products, the discharge of which causes almost universal pollution of natural waters. This process progresses rapidly over time, covering ever larger areas of land and ocean waters. Pollution of individual rivers, lakes and a number of areas of the World Ocean has reached such limits that it has begun to disrupt their biological regime. In vast areas of the Earth, a shortage of drinking and industrial water began to be felt.

The sanitary condition deteriorates especially quickly and the greatest damage is caused to the fisheries of those rivers and lakes on the banks of which large industrial enterprises and cities are located. Isolated and poorly connected sea basins are also intensively polluted. The ever-increasing pollution of water and soil with harmful chemicals in such basins often causes the emergence of processes that entail the death of flora and fauna, including the mass death of valuable species of commercial fish.

However, although water pollution has become global in nature, at present there is clearly a lag between the growth trends in pollution and the pace of production development. This happens due to the fact that technological progress ensures increasingly complete use of industrial raw materials and fuel, as a result of which their losses are significantly reduced. Closed production cycles and dry (water-free) technology are beginning to be widely used. The trend of converting enterprises and transport to electrical energy from nuclear power plants is intensifying. All existing and newly built large industrial enterprises, as a rule, provide for the construction of a special wastewater treatment complex. In some cases, the effectiveness of these measures is so great that individual, previously heavily polluted water bodies have been almost completely cleaned up and the restoration of flora and fauna has begun. This, naturally, is facilitated by the self-purifying ability of water basins (which, however, is limited to certain limits).

Every year around the world, about 6.5 million tons of phosphates, more than 5 million tons of petroleum products, 2.3 million tons of lead, 1.6 million tons of manganese and a large number of other chemicals are released into rivers, lakes and seas in the form of industrial waste. elements. As a rule, these substances are discharged in the form of aqueous solutions, or suspensions, since water is almost always a component of technological processes. When producing 1 ton of cast iron, depending on the technology used, from 150 to 200 cubic meters are consumed. m of water, to obtain the same amount of paper requires 65-110 cubic meters. m, pulp 175-500 cubic meters. m, petroleum products 2-20 cubic meters. m of water, etc. The largest volume of contaminated water is discharged by oil refineries, metallurgical, chemical and pulp and paper enterprises. Large quantities of chemicals enter groundwater and river waters from agricultural lands, where they are used as fertilizers and to control pests of crops and forests. Water basins are heavily polluted by petroleum products discharged by ships, as well as as a result of the leakage of crude oil in places of its production (especially underwater) and during the transportation of petroleum products.

The composition of wastewater contaminated with waste from industry, transport, agriculture and municipal enterprises includes organic substances (organic acids, alcohols, phenols, herbicides, detergents, etc.), inorganic substances (salts, acids, alkalis), petroleum products, toxic substances (cyanides, arsenic, copper salts, zinc, mercury, etc.), radioactive and bacteriological substances, etc.

Based on the nature of their impact, all pollutants can be divided into three types of agents: chemical, bacteriological and radioactive.

§ 1. Chemical pollution

Among the chemical pollutants of water masses, the most dangerous are hydrocarbons, pesticides (pesticides, insecticides, fungicides, herbicides), mercury and detergents.

The amount of pollutants in water is usually negligible compared to its total mass, but they can cause great harm to animals and plants of the water body. This is facilitated by three circumstances: firstly, the natural ability of a number of organisms to accumulate pollution products; secondly, most of the pollution is localized in coastal areas where most fish and other aquatic organisms breed, feed and grow; thirdly, a certain stability of the preservation of pollutants in the aquatic environment.

The impacts of industrial effluents are poorly understood and almost nothing is known about the cumulative effects of pollutants on aquatic organisms. It is known, for example, that nickel is relatively low-toxic. But if it gets into water with “copper runoff”, its toxicity increases 10 times. Almost nothing is known about the intensification of the effects of pollutants with an increase in water temperature, its density, salinity, changes in lighting conditions, water mixing and the impact of other factors.

All this is the subject of further study.

Hydrocarbons are the main component of oil and petroleum products - not only the most common, but also the most dangerous agent of pollution. Oil production and the use of petroleum products are growing rapidly. Therefore, the danger of contamination of natural waters with these substances is constantly increasing, significantly exceeding in scale the danger of bacteriological and radioactive contamination.

Petroleum products are a complex mixture of saturated, unsaturated, alicyclic and aromatic hydrocarbons. In 1968, the working group of the CMEA countries on the unification of methods for analyzing natural and waste waters decided to consider “petroleum products” the most characteristic part of oil and its products, consisting of non-polar and low-polar compounds extracted with hexane (or petroleum ether). This definition limits the concept of “petroleum products” to hydrocarbons and a very small number of organic compounds that are rarely associated with hydrocarbons in natural and waste waters. At the same time, this definition quite clearly expresses the chemical and analytical properties of petroleum products.

Oil in water can be present in the form of a film consisting mainly of light oily and oily-resinous fractions, in the form of a stable highly dispersed emulsion (particles less than 30 microns) in suspension, in the form of relatively large lumps adhered to suspended sediment, in dissolved form (oil solubility is insignificant - according to some authors, from 2 to 100 mg/l). Heavy fractions of oil (30-40%) sink to the bottom and form a layer that is very resistant to oxidation, in which organisms living on the bottom and serving as food for fish die. With waves and a sharp increase in the speed of bottom currents, oil products on the bottom can again be involved in hydrodynamic processes and become a secondary source of water pollution during resuspension.

Pesticide. To combat agricultural and forest pests, a large number of different toxic substances are used, which have strong toxic and carcinogenic properties. Since the beginning of World War II, dichlorodiphenyltrichloroatane (DDT) has been widely used to control field pests. The persistence of this drug has led to the fact that living creatures living in water, air and on land (including humans) currently contain DDT. Now the production of DDT has been significantly reduced. Some countries (including the Soviet Union) have completely abandoned its production and use.

Mercury and other metals enter natural waters along with waste from industrial enterprises and agriculture. Mercury, in particular, is used for seed treatment, in the pulp and paper industry, as a catalyst in the production of polyvinyl chloride and in other industries. Mercury has a strong toxic effect, can accumulate in animal and plant organisms and be transmitted through the biological food chain. About 100 Japanese died as a result of poisoning from fish caught in Minamata Bay, where waste from a polyvinyl chloride plant was dumped.

Hundreds of thousands of tons of lead and zinc also get into the water, which, like mercury, are toxic and accumulate in large quantities in aquatic organisms. The normal concentration of copper in seawater is approximately 3 parts per billion parts of water. A solution containing one part copper to 10 million parts water is toxic to aquatic organisms. The concentration - one part copper per million parts water - kills edible shellfish in less than 2 hours, and the ability of brown algae to produce oxygen is reduced under these conditions by about 70% within 9 days.

Detergents are synthetic surfactants that degrade very slowly (for example, Novost, Ladoga soaps, etc.). Wastewater containing detergents mainly pollutes rivers and coastal areas. The presence of surfactants can be determined both by directly measuring surface tension and by determining the intensity of foam formation: the presence of even a small amount of detergents in water becomes noticeable (including when observed from low altitudes from an airplane) due to the formation of foam.

Detergents pose a great threat to the reservoir, since foaming water inhibits the processes of mineralization of organic substances, reduces the organoleptic properties of water, and complicates the sedimentation and decomposition of suspended matter. It is known that under the same conditions, the oxidation of dissolved organic pollutants proceeds 10-25 times faster than the oxidation of undissolved suspended substances.

Detergents used to clean sea coasts from oil products have a more destructive effect on the flora and fauna of the sea than the oil itself.

§ 2. Bacteriological contamination

Pollution containing bacteria dangerous to human and animal life enters water bodies and watercourses mainly through sewer systems. Bacteria that enter the aquatic environment are partially neutralized over time. Therefore, the greatest danger is the direct discharge of sewage water into bodies of water used for water supply or bathing. In the seas, the danger of bacterial infection is relatively low, since sea water has the ability to destroy pathogenic microorganisms: during the first 15 hours, 70% of the bacteria die off, and on the fifth day only a fraction of a percent remains. However, even during this period, bacteria can cause great harm. The intensity of the processes of biochemical oxidation of wastewater depends on the water temperature. At a temperature of 20° C, their complete oxidation usually occurs within 5-10 days. At lower temperatures this period increases noticeably.

§ 3. Radioactive contamination

Radioactive contamination of water masses is created either as a result of the deliberate discharge into water (“burial”) of solid radiodecay products, which sink to the bottom, polluting water and soil, or as a result of the discharge of industrial water containing radioactive substances, or as a result of radioactive fallout formed during explosions of atomic bombs.

The most dangerous are radioactive elements that have a long half-life. Among them, strontium-90 and cesium-137 are in first place, having a half-life of about 30 years. These elements are absorbed by aquatic organisms and are included in biological processes, giving rise to harmful mutations.

Observations of radioactivity in waters are carried out in the same way as for pathogenic microbes: through sampling for chemical analysis. The distribution of jets of radioactive (as well as bacteriologically contaminated) industrial waters that have a specific color can be traced by mapping them from an airplane. In cases where they are not colored, they can be artificially masked with some kind of coloring substance at the point of discharge.

Introduction…………………………………………………………………………………3

Pollution of the water basin and monitoring the state of the hydrosphere……5

Environmental pollution………………………………………...5

Consequences of pollution……………………………………………………………...9

Cleaning steps………………………………………………………...11

Conclusion………………………………………………………………………………..16

References…………………………………………………………….17

Introduction

The hydrosphere is the water shell of the Earth, representing the totality of all types of reservoirs, including groundwater. Water is the only natural liquid available on the surface of the Earth in large quantities - 1386 million km 3, and it is found not only in the hydrosphere, but partially in the atmosphere (0.001%) and the lithosphere (1.72%).

Life on Earth is mainly dependent on fresh water (2.5% of total water). The role of water in all life processes is decisive. Plants contain 90% water by weight. The human body consists of 2/3 water, thanks to which the “transport” of all substances in the human body occurs. The loss of 15% of the body's water supply is dangerous for human life. Blood is 80% water. The main cause of natural human death is dehydration.

All water losses in the human body are replaced with drinking and food; a person consumes about 1 ton of water per year; The vast majority of fresh water reserves are difficult to access, 80% of it is contained in ice sheets or is located at various depths of the earth's crust (up to 200 m). The most valuable part of water resources (renewed water) is contained in rivers, which are sources of water supply for the population and industry, sources of energy, and a fishing base. Solar energy brings water into a constant cycle, due to which water in rivers is exchanged in 10-12 days.

However, the anthropogenic factor makes its own “corrections” both to the water renewal regimes and to the constant change in water quality. These “corrections” amount to waste transportation, with most of the river water used being returned as wastewater.

Atmospheric pollution, which has become large-scale, has caused damage to rivers, lakes, reservoirs, and soils. Pollutants and products of their transformations sooner or later reach the Earth's surface from the atmosphere. This already big problem is significantly aggravated by the fact that waste flows directly into water bodies and onto the ground. Huge areas of agricultural land are exposed to various pesticides and fertilizers, and landfill areas are growing. Industrial enterprises discharge wastewater directly into rivers. Runoff from fields also flows into rivers and lakes. Groundwater, the most important reservoir of fresh water, is also polluted. Pollution of fresh water and land boomerangs back to humans in food and drinking water.

Water pollutionand monitoring the state of the hydrosphere

WATER POLLUTION is an environmental crime under Art. 250 of the Criminal Code of the Russian Federation. The objective side consists of pollution, clogging, depletion of surface or underground waters, sources of drinking water supply, or other changes in their natural properties, if this resulted in significant harm to the animal or plant world, fish stocks, forestry or agriculture. Depending on the severity of the consequences and other circumstances, it may be considered an administrative offense.

Several Norilsk Nickel enterprises violate water laws by releasing harmful substances into the water. Rosprirodnadzor specialists came to this conclusion following an inspection of the company’s Polar Branch. In particular, it was discovered that industrial wastes with high contents of iron, nickel, petroleum products, lead, copper, chlorides, nitrates, calcium, magnesium, phosphates and zinc are poured into the water.

1. Pollution

The introduction of new, uncharacteristic physical, chemical and biological agents or exceeding their natural level.

Any chemical contamination is the appearance of a chemical substance in a place not intended for it. Pollution arising from human activity is the main factor in its harmful effects on the natural environment. Chemical pollutants can cause acute poisoning, chronic diseases, and also have carcinogenic and mutagenic effects. For example, heavy metals can accumulate in plant and animal tissues, causing toxic effects. Sources of environmental pollution include by-products of the pulp and paper industry, waste from the metallurgical industry, and exhaust gases from internal combustion engines. These substances are very toxic to humans and animals even at low concentrations and cause damage to the liver, kidneys, and immune system.

Along with environmental pollution by new synthetic substances, great damage to nature and human health can be caused by interference in natural cycles of substances due to active production and agricultural activities, as well as the generation of household waste.

Sea water also ceases to be water: many coasts are washed by a liquid with a completely different chemical composition than the one that sea water had several decades ago. Symptoms of degradation of the flora and fauna of the World Ocean have been noticed by researchers at great depths, even far from the coasts. But the World Ocean is the cradle of life and the “weather factory” on the whole Earth. If we continue to pollute it, it will soon make it impossible for life to exist on our planet.
Water is a necessary condition for life on Earth. Pollution of water bodies with various wastes complicates self-purification processes, which, along with a lack of fresh water, pose a threat to human health.
Water pollution can have harmful effects on human health in two ways:

Water pollution manifests itself in changes in physical and organoleptic properties (impaired transparency, color, odors, taste), an increase in the content of sulfates, chlorides, nitrates, toxic heavy metals, a reduction in air oxygen dissolved in water, the appearance of radioactive elements, pathogenic bacteria and other pollutants. Russia has one of the highest water potentials in the world - each resident of Russia accounts for over 30,000 m3/year of water. However, currently, due to pollution or clogging, about 70% of Russian rivers and lakes have lost their quality as a source of drinking water supply, as a result, about half of the population consumes contaminated, poor-quality water.

Natural bodies of water are not a natural habitat for pathogens. In contrast, domestic wastewater always contains various microorganisms, some of which can be pathogenic. The potential danger of the spread of intestinal infections with water is judged by the presence in it of so-called indicator microorganisms, primarily E. coli. According to hygienic standards, the presence of no more than 3 E. coli in 1 liter is allowed in drinking water. It has been proven that after water is disinfected with chlorine, ultraviolet rays, ozone or gamma radiation when it contains about three E. coli per liter, the water no longer contains viable microbial pathogens of abdominal typhoid, dysentery and others. However, the resistance of pathogenic viruses is higher than that of E. coli. Currently, complete confidence in the disinfection of drinking water can only be achieved by boiling it.

In waters containing fecal matter, plant or animal residues coming from food industry enterprises, paper fibers and cellulose residues from pulp and paper industry enterprises, the decomposition processes proceed almost identically. Since aerobic bacteria use oxygen, the first result of the breakdown of organic residues is a decrease in the amount of oxygen dissolved in the receiving waters. It varies depending on temperature, and also to some extent on salinity and pressure. Fresh water at 20° C and intensive aeration contains 9.2 mg of dissolved oxygen in one liter. As the water temperature increases, this indicator decreases, and when it cools, it increases.

In small streams with fast currents, where the water is intensively mixed, oxygen coming from the atmosphere compensates for the depletion of its reserves dissolved in the water. At the same time, carbon dioxide formed during the decomposition of substances contained in wastewater evaporates into the atmosphere. This reduces the period of adverse effects of organic decomposition processes. Conversely, in bodies of water with weak currents, where the waters mix slowly and are isolated from the atmosphere, an inevitable decrease in oxygen content and an increase in carbon dioxide concentration entail serious changes. When the oxygen content decreases to a certain level, fish die and other living organisms begin to die, which, in turn, leads to an increase in the volume of decomposing organic matter.
Most fish die due to poisoning from industrial and agricultural wastewater, but many also die from a lack of oxygen in the water. Fish, like all living things, absorb oxygen and release carbon dioxide. If there is little oxygen in the water, but a high concentration of carbon dioxide, the intensity of their respiration decreases (it is known that water with a high content of carbonic acid, i.e. carbon dioxide dissolved in it, becomes acidic).

2. Consequences of hydrosphere pollution.

Pollution of aquatic ecosystems poses a huge danger to all living organisms and, in particular, to humans. It has been established that under the influence of pollutants in freshwater ecosystems there is a decrease in their stability due to disruption of the food pyramid and breakdown of signal connections in the biocenosis, microbiological pollution, eutrophication and other extremely unfavorable processes. They reduce the growth rate of aquatic organisms, their fertility, and in some cases lead to their death. The process of eutrophication of water bodies is the most studied.

Eutrophication– enrichment of the reservoir with nutrients, stimulating the growth of phytoplankton. As a result, the water becomes cloudy, plants die, the concentration of dissolved oxygen decreases, and fish and shellfish living in the depths suffocate. This natural process, characteristic of the entire geological past of the planet, usually proceeds very slowly and gradually, but in recent decades, due to increased anthropogenic impact, the speed of its development has increased sharply.
Accelerated, or so-called anthropogenic eutrophication is associated with the entry into water bodies of a significant amount of nutrients - nitrogen, phosphorus and other elements in the form of fertilizers, detergents, animal waste, atmospheric aerosols, etc. The destruction of the Baltic Sea occurs as a result of the process of eutrophization (enrichment reservoir with nutrients that stimulate the growth of phytoplankton). This form of pollution is typical for water spaces in which water is renewed slowly. This is the case with the practically closed Baltic Sea. Eutrophication occurs when the sea receives too many nutrients. These substances, in this case phosphorus and nitrogen, which are present in nature, are also found in fertilizers and household chemical products. Algae assimilate them and begin to multiply rapidly. One of the consequences of this "explosive" reproduction, increasingly observed in the summer months, is the disappearance of oxygen from deep waters. The Baltic Sea has the unfortunate reputation of being the most polluted sea on the planet. Shipping traffic here is the heaviest in the world, and some species of fish caught here, particularly herring and salmon, are prohibited from export to the European Union. The processes of anthropogenic eutrophization also cover many large lakes of the world - the Great American Lakes, Lake Balaton, Ladoga, Geneva, etc., as well as reservoirs and river ecosystems, primarily small rivers.

In addition to the excess of nutrients, other pollutants also have a detrimental effect on freshwater ecosystems: heavy metals (lead, cadmium, nickel, etc.), phenols, surfactants, etc. For example, the aquatic organisms of Lake Baikal, which have adapted in the process of long evolution to a natural set chemical compounds of the lake's tributaries turned out to be incapable of processing chemical compounds alien to natural waters (petroleum products, heavy metals, salts).

The rate at which pollutants enter the World Ocean has increased sharply in recent years. Every year, up to 300 billion m3 of wastewater is discharged into the ocean, 90% of which is not pre-treated.

The problems of eutrophication and microbiological pollution of coastal ocean zones are becoming increasingly acute. In this regard, it is important to determine the permissible anthropogenic pressure on marine ecosystems and study their assimilation capacity as an integral characteristic of the ability of a biogeocenosis to dynamically accumulate and remove pollutants.

The most serious environmental problem is the restoration of water content and purity of small rivers (i.e., rivers no more than 100 km long), the most vulnerable link in river ecosystems. They turned out to be the most susceptible to anthropogenic impact. Ill-conceived economic use of water resources and adjacent land has caused their depletion (and often disappearance), shallowing and pollution. Currently, the condition of small rivers and lakes, especially in the European part of Russia, as a result of the sharply increased anthropogenic load on them, is catastrophic. The flow of small rivers has decreased by more than half, and the water quality is unsatisfactory. Many of them completely ceased to exist.

Cleaning steps.

A sanitary sewer system integrates all waste pipes from sinks, bathtubs, etc. located in buildings, just like a tree trunk connects all its branches. From the base of this “trunk” flows a mixture of everything that has entered the system - raw wastewater . Since we use huge volumes of water to remove tiny amounts of waste or simply pour it unnecessarily, in primary waste water there are approximately 1000 parts of water for every part of waste, i.e. they contain 99.9% water and 0.1% waste. With the addition of stormwater, the dilution increases further. But waste or pollutants from primary effluents are of great importance. They are divided into three categories.

Garbage and sand. Garbage- these are rags, plastic bags and other items that enter the system from toilets or through storm drains, if they are not already separated. TO sand conditionally includes gravel; They are brought mainly by storm drains.

organic matter, or colloids. These are both living organisms and non-living organic matter of excrement, food waste and fibers of fabrics and paper. Term colloids means that this material does not settle but usually remains suspended in the water.

Dissolved substances. These are mainly biogens, such as nitrogen, phosphorus and potassium compounds from waste products, enriched with phosphates from detergents.

For treatment to be complete, water treatment plants must eliminate all named categories of pollutants. Garbage and sand are removed at the stage pre-treatment.

Combination primary And secondary treatment allows you to get rid of colloidal material. Dissolved nutrients are eliminated using post-treatment.

It must also be borne in mind that wastewater treatment in each specific case does not necessarily have to include all four stages. Most often they complement each other depending on the circumstances. Consequently, in some places they still simply discharge raw wastewater into reservoirs, in others they carry out only primary treatment, in some places they carry out secondary treatment, and only a few cities carry out additional treatment of drains.

Pre-cleaning. Garbage is disposed of by passing the original wastewater through bar grid, i.e. a series of rods located at a distance of about 2.5 cm from each other. The waste is then mechanically collected from the grate and sent to a special incineration oven. The water, cleared of debris, enters a container resembling a swimming pool, where the movement of the water slows down so much that the sand settles; it is then mechanically removed from there and taken to a landfill.

Primary cleaning. After pre-treatment, the water undergoes primary purification - it is slowly passed through large tanks called primary settling tanks. Here she remains almost motionless for several hours. This allows the heaviest particles of organic matter, constituting 30-50% of the total, to settle to the bottom, from where they are collected. At the same time, fatty and oily substances float to the surface and are skimmed off like cream. All this material is called raw sludge. The water leaving the primary settling tanks still contains 50-70% unsettled organic colloids and almost all dissolved nutrients. Secondary treatment involves removing remaining organic matter but not dissolved nutrients.

Secondary cleaning. This cleaning is also called biological, since it involves living natural decomposers and detritivores that consume organic matter and, in the process of respiration, convert it into water and carbon dioxide. Two types of systems are commonly used: trickling biofilters and activated sludge. In systems with drip biofilter water splashes and flows in streams over a layer of stones the size of a fist, the thickness of which is 2-3 m. Organisms accidentally washed off from biofilters are later eliminated from the water when it enters secondary settling tanks, similar to primary settling tanks. The material settled in them is treated as with raw sludge. After undergoing primary treatment and drip biofilters, wastewater loses 85-90% of organic matter. Another method of secondary purification is becoming increasingly widespread - activated sludge system. In this case, the water after initial purification enters a reservoir that could accommodate several trailers parked one behind the other. A detritivorous mixture called activated sludge is added to the water as it enters the reservoir. As it moves, it creates an oxygen-rich environment ideal for the development of these organisms. As they feed, the amount of organic matter, including pathogenic microorganisms, decreases. Leaving the aeration tank, the water contains many detritivores, so it is sent to secondary settling tanks. Because organisms typically accumulate in pieces of detritus, settling them is relatively easy; the sediment is the same activated sludge, which is pumped back into the aeration tank. Water is purified from organic matter by 90-95%. Until the last two decades, there was no urgent need to carry out additional water purification after secondary water treatment. Afterwards, the water was simply disinfected with bleach and discharged into natural reservoirs. This situation still prevails today. However, as the problem of eutrophication worsens, more and more cities are introducing another stage - post-treatment, eliminating nutrients.

Additional treatment. After secondary purification, the water goes to post-treatment, which eliminates one or more nutrients. There are many ways to do this. Water can be 100% purified by distillation or microfiltration. Purifying such an amount of water using the above methods is too wasteful, so more affordable methods are currently being developed and implemented. For example, phosphates can be eliminated by adding lime (calcium ions) to the water. Calcium reacts chemically with phosphate to form insoluble calcium phosphate, which can be removed by filtration. If excess phosphate is the main cause of eutrophication, this is already enough. With appropriate purification, it is possible to ensure that the resulting water is suitable for drinking.

Disinfection. No matter how thoroughly wastewater is treated, it is usually still disinfected by chlorination before being discharged into natural bodies of water to destroy pathogenic organisms that may have survived. The use of chlorine gas (Cl2) for this purpose entails certain environmental issues that require discussion. There are safer disinfectants, such as ozone (O3). It is extremely destructive to microorganisms and, acting on them, breaks down into gaseous oxygen, which improves the quality of water. However, ozone is not only toxic, but also explosive. It is also proposed to expose water to ultraviolet or other radiation that kills microorganisms but does not have any side effects.

Conclusion.

The water cycle, this long path of its movement, consists of several stages: evaporation, cloud formation, rainfall, runoff into streams and rivers, and evaporation again. Throughout its entire path, water itself is capable of purifying itself from contaminants that enter it.

Theoretically, water resources are inexhaustible, since with rational use they are continuously renewed in the process of the water cycle in nature. Even in the recent past, it was believed that there was so much water on Earth that, with the exception of some arid areas, people did not need to worry about running out of it. However, water consumption is growing at such a rate that humanity is increasingly faced with the problem of how to meet future needs for it. In many countries and regions of the world today there is already a shortage of water resources, which is increasing every year.

The problem of land water pollution (rivers, lakes, reservoirs, groundwater) is closely related to the problem of fresh water supply, therefore special attention is paid to monitoring and monitoring the level of pollution of water bodies. Economic regulation of the rational use and protection of water includes: planning and financing of measures for the rational use and protection of water; setting water use limits; establishing payment standards for water use and water consumption; establishing payment standards for discharges of pollutants into water bodies; provision of tax, credit and other benefits when using low-waste and non-waste technologies, carrying out other activities when they have a significant effect in the field of rational use and protection of water; coverage of damage caused to water bodies and human health due to violation of water legislation.

Literature

Yu.V. Novikov, Ecology, environment and people. 2000 p.320

A.N. Pavlov, V.M. Kirillov, Life safety and prospects for environmental development, 2002, p. 352

Ecology. V.I.Korobkin, L.V.peredelsky, 2003 p.576

Engineering ecology and environmental management / ed. N.I.Ivanova and I.M.Fadina, Moscow 2001. p.528

Since the time of the scientific and technological revolution, humanity has been rapidly destroying nature and its resources, thinking less and less about their difficulty in replenishment.

Nuclear energy, the development of metallurgy and the chemical industry - active human activity leaves its mark on all elements of the environment: flora, fauna, air, soil, water.

The abundant waste of natural resources has prompted scientists to consider environmental issues, identifying key pollutants and methods to combat them.

A distinction is made between primary and secondary pollution: with primary pollution, harmful substances are formed directly during natural or anthropogenic processes, and with secondary pollution, harmful substances are formed in the environment from primary ones. In most cases, secondary pollutants are more toxic than primary pollutants.

Methods of influence

The mechanism of action of the pollutant can be different: some substances are irritating, changing the acidity level of the mucous membrane or irritating the nerve endings; others change the ratio of redox reactions in the body; still others replace chemical elements and compounds in cells; fourth - influence electromagnetic and mechanical oscillatory processes in the body.

Categories

Technogenic pollutants are classified into the following categories:

1. Origin(mechanical, biological, physical, chemical, energy and material).
2. Duration of action(medium stability, semi-resistant, unstable and stable).
3. Influence(indirect and direct).
4. Character(accidental, accompanying, intentional).
5. Danger level(toxicity level).
6. Prevalence(local, regional, global, space).

Origin

Based on their origin, the following types are distinguished:

And the most common is mechanical pollution of the environment, since every inhabitant of the planet faces this every day. The bulk of mechanical waste is plastic, which practically does not decompose, so nature, despite the presence of protective mechanisms in it, is not able to cope with mechanical waste on its own. It is also directly related to the continuous process of the widespread construction of new buildings by man. All kinds of landfills, where large quantities of solid household waste are stored, are places of environmental disasters.

Chemical as the most common

Chemical pollution regularly attacks all parts of the biosphere, as daily chemical emissions amount to tons. It affects the balance of microelements, depletes the microflora, reduces the productivity of ecosystem elements and generally disrupts its balance.

Chemical elements such as heavy metals (including cadmium, arsenic, mercury and lead) require special control, the distribution of which is facilitated by metallurgical plants, factories, industrial warehouses and enterprises whose activities are related to the search for minerals.

Pesticides, which are used to protect plants from pests and control disease vectors, play an important role in chemical pollution. Technogenic soil pollution is a type that is deliberately introduced into nature by humans. Pesticides can affect the central nervous system, provoke allergic reactions, cause cancer, and even change the genetic code.
Mutating pests, against which pesticides were originally aimed, provoke people to throw out chemicals in even greater quantities.

The release of chemicals affects not only the soil, flora and fauna. Man-made atmospheric pollution is characterized by an abundance of sulfur gas, which leads to acid rain, which infects and destroys clean water bodies and forests. The consequences of using aerosol sprays can even lead to the destruction of the planet’s ozone layer, which protects all its inhabitants from ultraviolet radiation.

Environmental situation in Russia

The environmental situation in our country is tense. Lack of funding and a general policy of laissez-faire towards a clean environment only contributes to the deterioration of the situation.

Industrial emissions reduce the frost resistance of plants, which affects agriculture. The northern regions of Russia, with their characteristic humid and cloudy climate, coupled with the presence of toxic substances in the atmosphere, threaten the extinction of plants and the formation of wastelands.

There are also a number of natural factors that also do not contribute to the cleansing of the biosphere: the soil has the property of accumulating radiation that enters it with waste and radioactive fallout after nuclear tests. Because of this, radioactive substances are included in food chains and affect living organisms.