The main sources of pollution of the world's oceans are as follows. Environmental problems - water pollution

1. Features of the behavior of pollutants in the ocean

2. Anthropogenic ecology of the ocean - a new scientific direction in oceanology

3. The concept of assimilation capacity

4. Conclusions from the assessment of the assimilation capacity of the marine ecosystem by pollutants on the example of the Baltic Sea

1 Features of the behavior of pollutants in the ocean. Recent decades have been marked by increased anthropogenic impacts on marine ecosystems as a result of pollution of the seas and oceans. The spread of many pollutants has become local, regional and even global. Therefore, pollution of the seas, oceans and their biota has become a major international problem, and the need to protect the marine environment from pollution is dictated by the requirements of the rational use of natural resources.

Marine pollution is defined as: “The introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) that causes harmful effects such as damage to living resources, danger to human health, interference with marine activities, including fishing, deterioration of sea water quality and reduction of its useful properties. This list includes substances with toxic properties, discharges of heated waters (thermal pollution), pathogenic microbes, solid wastes, suspended solids, nutrients and some other forms of anthropogenic impacts.

The most urgent problem in our time has become the problem of chemical pollution of the ocean.

The sources of pollution of the ocean and seas include the following:

Discharge of industrial and economic waters directly into the sea or with river runoff;

Intake from land of various substances used in agriculture and forestry;

Intentional dumping of pollutants at sea; leakage of various substances during ship operations;

Accidental releases from ships or subsea pipelines;

Development of minerals on the seabed;

Transport of pollutants through the atmosphere.

The list of pollutants received by the ocean is extremely extensive. All of them differ in the degree of toxicity and the scale of distribution - from coastal (local) to global.

More and more pollutants are being found in the oceans. The most dangerous for organisms organochlorine compounds, polyaromatic hydrocarbons and some others are becoming globally widespread. They have a high bioaccumulative capacity, a sharp toxic and carcinogenic effect.

The steady increase in the total impact of many pollution sources leads to progressive eutrophication of coastal marine zones and microbiological water pollution, which significantly complicates the use of water for various human needs.

Oil and oil products. Oil is a viscous oily liquid, usually dark brown in color and with low fluorescence. Oil consists mainly of saturated aliphatic and hydroaromatic hydrocarbons (from C 5 to C 70) and contains 80-85% C, 10-14% H, 0.01-7% S, 0.01% N and 0-7% O 2.

The main components of oil - hydrocarbons (up to 98%) - are divided into four classes.

1. Paraffins (alkanes) (up to 90% of the total composition of oil) are stable saturated compounds C n H 2n-2, the molecules of which are expressed by a straight or branched (isoalkanes) chain of carbon atoms. Paraffins include the gases methane, ethane, propane and others, compounds with 5-17 carbon atoms are liquids, and those with a large number of carbon atoms are solids. Light paraffins have maximum volatility and solubility in water.

2. Cycloparaffins. (naphthenes)-saturated cyclic compounds C n H 2 n with 5-6 carbon atoms in the ring (30-60% of the total oil composition). In addition to cyclopentane and cyclohexane, bicyclic and polycyclic naphthenes are found in oil. These compounds are very stable and difficult to biodegrade.

3. Aromatic hydrocarbons (20-40% of the total composition of oil) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than the corresponding naphthenes. The carbon atoms in these compounds can also be replaced by alkyl groups. Oil contains volatile compounds with a molecule in the form of a single ring (benzene, toluene, xylene), then bicyclic (naphthalene), tricyclic (anthracene, phenanthrene) and polycyclic (for example, pyrene with 4 rings) hydrocarbons.

4. Olephips (alkenes) (up to 10% of the total composition of oil) are unsaturated non-cyclic compounds with one or two hydrogen atoms at each carbon atom in a molecule that has a straight or branched chain.

Depending on the field, oils differ significantly in their composition. Thus, Pennsylvania and Kuwaiti oils are classified as paraffinic, Baku and California - mainly naphthenic, the rest of the oils - intermediate types.

Oil also contains sulfur-containing compounds (up to 7% sulfur), fatty acids (up to 5% oxygen), nitrogen compounds (up to 1% nitrogen) and some organometallic derivatives (with vanadium, cobalt and nickel).

Quantitative analysis and identification of petroleum products in the marine environment present significant difficulties not only because of their multicomponent nature and different forms of existence, but also due to the natural background of hydrocarbons of natural and biogenic origin. For example, about 90% of low molecular weight hydrocarbons such as ethylene dissolved in the surface waters of the ocean is associated with the metabolic activity of organisms and the decay of their residues. However, in areas of intense pollution, the level of content of such hydrocarbons increases by 4-5 orders of magnitude.

Hydrocarbons of biogenic and petroleum origin, according to experimental studies, have a number of differences.

1. Oil is a more complex mixture of hydrocarbons with a wide range of structures and relative molecular weights.

2. Oil contains several homologous series, in which neighboring members usually have equal concentrations. For example, in the C 12 -C 22 series of alkanes, the ratio of even and odd members is equal to one, while biogenic hydrocarbons in the same series contain predominantly odd members.

3. Oil contains a wider range of cycloalkanes and aromatics. Many compounds such as mono-, di-, tri- and tetramethylbenzenes are not found in marine organisms.

4. Oil contains numerous naphtheno-aromatic hydrocarbons, various heterocompounds (containing sulfur, nitrogen, oxygen, metal ions), heavy asphalt-like substances - all of them are practically absent in organisms.

Oil and oil products are the most common pollutants in the oceans.

The routes of entry and forms of existence of petroleum hydrocarbons are diverse (dissolved, emulsified, filmy, solid). M. P. Nesterova (1984) notes the following ways of admission:

discharges in ports and near-port water areas, including losses when loading bunkers of tankers (17%~);

Discharge of industrial waste and sewage (10%);

Storm drains (5%);

Disasters of ships and drilling rigs at sea (6%);

Offshore drilling (1%);

Atmospheric fallout (10%)",

Removal by river runoff in all variety of forms (28%).

Discharges into the sea of washing, ballast and bilge water from ships (23%);

The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes.

The property of oils is their fluorescence under ultraviolet irradiation. The maximum fluorescence intensity is observed in the wavelength range 440-483 nm.

The difference in the optical characteristics of oil films and sea water allows remote detection and evaluation of oil pollution on the sea surface in the ultraviolet, visible and infrared parts of the spectrum. For this, passive and active methods are used. Large masses of oil from land enter the seas along rivers, with domestic and storm drains.

The fate of oil spilled into the sea is determined by the sum of the following processes: evaporation, emulsification, dissolution, oxidation, formation of oil aggregates, sedimentation and biodegradation.

Getting into the marine environment, oil first spreads in the form of a surface film, forming slicks of various thicknesses. By the color of the film, you can approximately estimate its thickness. The oil film changes the intensity and spectral composition of the light penetrating into the water mass. The light transmission of thin films of crude oil is 1-10% (280 nm), 60-70% (400 nm). An oil film with a thickness of 30-40 microns completely absorbs infrared radiation.

In the early days of oil slicks, the evaporation of hydrocarbons was of great importance. According to observations, up to 25% of light oil fractions evaporate in 12 hours; at a water temperature of 15 °C, all hydrocarbons up to C 15 evaporate in 10 days (Nesterova, Nemirovskaya, 1985).

All hydrocarbons have a low solubility in water, which decreases with increasing number of carbon atoms in the molecule. About 10 mg of compounds with C 6, 1 mg of compounds with C 8 and 0.01 mg of compounds with C 12 are dissolved in 1 liter of distilled water. For example, at an average temperature of sea water, the solubility of benzene is 820 µg/l, toluene - 470, pentane - 360, hexane - 138 and heptane - 52 µg/l. Soluble components, the content of which in crude oil does not exceed 0.01%, are the most toxic for aquatic organisms. They also include substances such as benzo(a)pyrene.

When mixed with water, oil forms two types of emulsions: direct "oil in water" and reverse "water in oil". Direct emulsions, composed of oil droplets with a diameter of up to 0.5 microns, are less stable and are especially characteristic of oils containing surfactants. After removal of volatile and soluble fractions, residual oil often forms viscous inverse emulsions, which are stabilized by high-molecular compounds such as resins and asphaltenes and contain 50-80% water (“chocolate mousse”). Under the influence of abiotic processes, the viscosity of the "mousse" increases and it begins to stick together into aggregates - oil lumps ranging in size from 1 mm to 10 cm (usually 1-20 mm). The aggregates are a mixture of high molecular weight hydrocarbons, resins and asphaltenes. Oil losses for the formation of aggregates are 5-10%. Highly viscous structured formations - "chocolate mousse" and oil lumps - can remain on the sea surface for a long time, be carried by currents, be thrown ashore and settle to the bottom. Oil lumps are often populated by periphyton (blue-green and diatoms, barnacles and other invertebrates).

Pesticides constitute an extensive group of artificially created substances used to control pests and plant diseases. Depending on the intended purpose, pesticides are divided into the following groups: insecticides - to combat harmful insects, fungicides and bactericides - to combat fungal and bacterial plant diseases, herbicides - against weeds, etc. According to economists' calculations, each ruble spent for the chemical protection of plants from pests and diseases, ensures the preservation of the crop and its quality in the cultivation of grain and vegetable crops by an average of 10 rubles, technical and fruit crops - up to 30 rubles. At the same time, environmental studies have established that pesticides, destroying crop pests, cause great harm to many beneficial organisms and undermine the health of natural biocenoses. Agriculture has long faced the challenge of shifting from chemical (polluting) to biological (environmentally friendly) methods of pest control.

Currently, more than 5 million tons of pesticides enter the world market annually. About 1.5 million tons of these substances have already entered the terrestrial and marine ecosystems by aeolian or aquatic routes. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater.

In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others.

Synthesized insecticides are divided into three main groups: organochlorine, organophosphorus and carbamates.

Organochlorine insecticides are obtained by chlorination of aromatic or heterocyclic liquid hydrocarbons. These include DDT (dichlorodiphenyltrichloroethane) and its derivatives, in whose molecules the stability of aliphatic and aromatic groups increases in the joint presence, various chlorinated derivatives of cyclodiene (eldrin, dil-drin, heptachlor, etc.), as well as numerous isomers of hexachlorocyclohexane (in -HCCH), of which lindane is the most dangerous. These substances have a half-life of up to several decades and are very resistant to biodegradation.

In the aquatic environment, polychlorinated biphenyls (PCBs) are often found - DDT derivatives without an aliphatic part, numbering 210 theoretical homologues and isomers.

Over the past 40 years, more than 1.2 million tons of PCBs have been used in the production of plastics, dyes, transformers, capacitors, etc. Polychlorinated biphenyls enter the environment as a result of industrial wastewater discharges and solid waste incineration in landfills. The latter source delivers PCBs to the atmosphere, from where they fall out with atmospheric precipitation in all regions of the globe. So, in snow samples taken in Antarctica, the content of PCBs was 0.03-1.2 ng/l.

Organophosphate pesticides are esters of various alcohols of phosphoric acid or one of its derivatives, thiophosphoric. This group includes modern insecticides with a characteristic selectivity of action in relation to insects. Most organophosphates are subject to fairly rapid (within a month) biochemical degradation in soil and water. More than 50,000 active substances have been synthesized, of which parathion, malathion, phosalong, and dursban are especially famous.

Carbamates are, as a rule, esters of n-metacarbamic acid. Most of them also have a selective action.

As fungicides used to combat fungal diseases of plants, copper salts and some mineral sulfur compounds were previously used. Then, organomercury substances such as chlorinated methylmercury were widely used, which, due to its extreme toxicity to animals, was replaced by methoxyethylmercury and phenylmercury acetates.

The group of herbicides includes derivatives of phenoxyacetic acid, which have a strong physiological effect. Triazines (for example, simazine) and substituted ureas (monuron, diuron, pichloram) constitute another group of herbicides, quite well soluble in water and stable in soils. Pichloram is the strongest of all herbicides. For the complete destruction of some plant species, only 0.06 kg of this substance per 1 ha is required.

DDT and its metabolites, PCBs, HCH, deldrin, tetrachlorophenol and others are constantly found in the marine environment.

Synthetic surfactants. Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (CMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the continental surface waters and the marine environment. Synthetic detergents contain sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: fragrances, bleaching agents (persulphates, perborates), soda ash, carboxymethyl cellulose, sodium silicates and others.

The molecules of all surfactants consist of hydrophilic and hydrophobic parts. The hydrophilic part is carboxyl (COO -), sulfate (OSO 3 -) and sulfonate (SO 3 -) groups, as well as accumulations of residues with groups -CH 2 -CH 2 -O-CH 2 -CH 2 - or groups containing nitrogen and phosphorus. The hydrophobic part usually consists of a straight line, including 10-18 carbon atoms, or a branched paraffin chain, from a benzene or naphthalene ring with alkyl radicals.

Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic (the organic ion is negatively charged), cationic (the organic ion is positively charged), amphoteric (displaying cationic properties in an acidic solution, and anionic in an alkaline solution) and nonionic. The latter do not form ions in water. Their solubility is due to functional groups that have a strong affinity for water and the formation of a hydrogen bond between water molecules and oxygen atoms included in the polyethylene glycol radical of the surfactant.

The most common among the surfactants are anionic substances. They account for more than 50% of all surfactants produced in the world. The most common are alkylarylsulfonates (sulfonols) and alkyl sulfates. Sulfonol molecules contain an aromatic ring, the hydrogen atoms of which are replaced by one or more alkyl groups, and a sulfuric acid residue as a solvating group. Numerous alkylbenzene sulfonates and alkylnaphthalenesulfonates are often used in the manufacture of various household and industrial CMCs.

The presence of surfactants in industrial wastewater is associated with their use in such processes as flotation beneficiation of ores, separation of chemical technology products, production of polymers, improvement of conditions for drilling oil and gas wells, and equipment corrosion control.

In agriculture, surfactants are used as part of pesticides. With the help of surfactants, liquid and powdered toxic substances that are insoluble in water, but soluble in organic solvents, are emulsified, and many surfactants themselves have insecticidal and herbicidal properties.

Carcinogenic substances- these are chemically homogeneous compounds that exhibit transforming activity and are capable of causing carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the exposure conditions, they can lead to growth inhibition, accelerated aging, toxicogenesis, disruption of individual development, and changes in the gene pool of organisms. Substances with carcinogenic properties include chlorinated aliphatic hydrocarbons with a short sliver of carbon atoms in the molecule, vinyl chloride, pesticides and, especially, polycyclic aromatic hydrocarbons (PAHs). The latter are high molecular weight organic compounds, in the molecules of which the benzene ring is the main element of the structure. Numerous unsubstituted PAHs contain from 3 to 7 benzene rings in the molecule, interconnected in various ways. There are also a large number of polycyclic structures containing a functional group either in the benzene ring or in the side chain. This halogen-, amino-, sulfo-, nitro derivatives, as well as alcohols, aldehydes, esters, ketones, acids, quinones and other aromatic compounds.

The solubility of PAHs in water is low and decreases with increasing molecular weight: from 16 100 µg/l (acenaphthylene) to 0.11 µg/l (3,4-benzpyrene). The presence of salts in water has practically no effect on the solubility of PAHs. However, in the presence of benzene, oil, oil products, detergents, and other organic substances, the solubility of PAHs sharply increases. Of the group of unsubstituted PAHs, 3,4-benzpyrene (BP) is the best known and widespread under natural conditions.

Natural and anthropogenic processes can serve as sources of PAHs in the environment. The concentration of BP in volcanic ash is 0.3-0.9 µg/kg. This means that 1.2-24 tons of BP per year can enter the environment with ash. Therefore, the maximum amount of PAHs in modern bottom sediments of the World Ocean (more than 100 μg/kg of dry matter mass) was found in tectonically active zones subject to deep thermal action.

Some marine plants and animals are reported to be able to synthesize PAHs. In algae and sea grasses near the western coast of Central America, the content of BP reaches 0.44 µg/g, and in some crustaceans in the Arctic, 0.23 µg/g. Anaerobic bacteria produce up to 8.0 μg of BP from 1 g of plankton lipid extracts. On the other hand, there are special types of marine and soil bacteria that decompose hydrocarbons, including PAHs.

According to L. M. Shabad (1973) and A. P. Ilnitsky (1975), the background concentration of BP created as a result of the synthesis of BP by plant organisms and volcanic activity is: in soils 5-10 µg/kg (dry matter), in plants 1-5 µg/kg, in freshwater reservoirs 0.0001 µg/l. Accordingly, gradations of the degree of pollution of environmental objects are also derived (Table 1.5).

The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel. The pyrolytic formation of PAHs occurs at a temperature of 650-900 °C and a lack of oxygen in the flame. The formation of BP was observed during the pyrolysis of wood with a maximum yield at 300–350°C (Dikun, 1970).

According to M. Suess (G976), the global emission of BP in the 70s was about 5000 tons per year, with 72% coming from industry and 27% from all types of open burning.

Heavy metals(mercury, lead, cadmium, zinc, copper, arsenic and others) are among the common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere. Mercury, lead and cadmium are the most dangerous for marine biocenoses.

Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 12 thousand tons of mercury, and a significant part of anthropogenic origin. As a result of volcanic eruptions and atmospheric precipitation, 50 thousand tons of mercury annually enter the ocean surface, and 25-150 thousand tons of mercury during degassing of the lithosphere. About half of the annual industrial production of this metal (9-10 thousand tons / year) in various ways falls into the ocean. The content of mercury in coal and oil is on average 1 mg/kg; therefore, when burning fossil fuels, the World Ocean receives more than 2 thousand tons/year. The annual production of mercury exceeds 0.1% of its total content in the World Ocean, but the anthropogenic influx already exceeds the natural removal by rivers, which is typical for many metals.

In areas polluted by industrial wastewater, the concentration of mercury in solution and suspension is greatly increased. At the same time, some benthic bacteria convert chlorides into highly toxic (mono- and di-) methylmercury CH 3 Hg. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. By 1977, there were 2,800 victims of Minamata disease in Japan. The reason was the waste of enterprises for the production of vinyl chloride and acetaldehyde, in which mercury chloride was used as a catalyst. Insufficiently treated wastewater from enterprises entered the Minamata Bay.

Lead is a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, lead is actively dissipated into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines.

According to V.V. Dobrovolsky (1987), the redistribution of lead masses between land and the World Ocean is as follows. C. river runoff at an average lead concentration in water of 1 μg / l into the ocean of water-soluble lead is carried out about 40 10 3 t / year, in the solid phase of river suspensions about 2800-10 3 t / year, in fine organic detritus - 10 10 3 t /year. If we take into account that more than 90% of river suspensions settle in a narrow coastal strip of the shelf and a significant part of water-soluble metal compounds are captured by iron oxide gels, then as a result, the ocean pelagial receives only about (200-300) 10 3 tons in the composition of fine suspensions and (25- 30) 10 3 tons of dissolved compounds.

The migration flow of lead from the continents to the ocean goes not only with river runoff, but also through the atmosphere. With continental dust, the ocean receives (20-30)-10 3 tons of lead per year. Its entry to the ocean surface with liquid atmospheric precipitation is estimated at (400-2500) 10 3 t/year at a concentration in rainwater of 1-6 µg/l. The sources of lead entering the atmosphere are volcanic emissions (15-30 t/year in the composition of pelitic eruption products and 4 10 3 t/year in submicron particles), volatile organic compounds from vegetation (250-300 t/year), combustion products from fires ((6-7) 10 3 t/year) and modern industry. Lead production increased from 20-103 tons/year at the beginning of the 19th century. up to 3500 10 3 t/year by the beginning of the 80s of the XX century. Modern release of lead into the environment with industrial and household waste is estimated at (100-400) 10 3 t/year.

Cadmium, whose world production in the 1970s reached 15 10 3 tons/year, also enters the ocean with river runoff and through the atmosphere. The volume of atmospheric removal of cadmium, according to various estimates, is (1.7-8.6) 10 3 t/year.

Discharge of waste into the sea for the purpose of disposal (dumping). Many countries with access to the sea undertake marine disposal of various materials and substances, in particular soil excavated during dredging, drill cuttings, industrial waste, construction debris, solid waste, explosives and chemicals, radioactive waste, etc. Volume landfills is about 10% of the total mass of pollutants entering the oceans. So, from 1976 to 1980, more than 150 million tons of various wastes were dumped annually for the purpose of burial, which defines the concept of "dumping".

The basis for dumping in the sea is the ability of the marine environment to process a large amount of organic and inorganic substances without much damage to water quality. However, this ability is not unlimited. Therefore, dumping is considered as a forced measure, a temporary tribute to the imperfection of technology by society. Hence, the development and scientific substantiation of ways to regulate waste discharges into the sea are of particular importance.

Industrial sludge contains a variety of organic substances and heavy metal compounds. Household garbage contains on average (on a dry matter basis) 32-40% organic matter, 0.56% nitrogen, 0.44% phosphorus, 0.155% zinc, 0.085% lead, 0.001% cadmium, 0.001 mercury. Sludge from municipal wastewater treatment plants contains (per dry matter weight) up to. 12% humic substances, up to 3% total nitrogen, up to 3.8% phosphates, 9-13% fats, 7-10% carbohydrates and are contaminated with heavy metals. Bottom grab materials have a similar composition.

During the discharge, when the material passes through the water column, part of the pollutants goes into solution, changing the quality of the water, while the other part is sorbed by suspended particles and goes into bottom sediments. At the same time, the turbidity of the water increases. The presence of organic substances often leads to the rapid consumption of oxygen in water and often to its complete disappearance, the dissolution of suspensions, the accumulation of metals in dissolved form, and the appearance of hydrogen sulfide. The presence of a large amount of organic matter creates a stable reducing environment in soils, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions in reduced form. In this case, the reduction of sulfates and nitrates, phosphates are released.

Neuston, pelagic and benthos organisms are affected to varying degrees by the discharged materials. In the case of the formation of surface films containing petroleum hydrocarbons and surfactants, gas exchange at the air-water interface is disturbed. This leads to the death of invertebrate larvae, fish larvae and fry, and causes an increase in the number of oil-oxidizing and pathogenic microorganisms. The presence of a polluting suspension in the water worsens the conditions of nutrition, respiration and metabolism of hydrobionts, reduces the growth rate, and inhibits the puberty of planktonic crustaceans. Pollutants entering the solution can accumulate in the tissues and organs of hydrobionts and have a toxic effect on them. The dumping of dumping materials to the bottom and prolonged increased turbidity of the bottom water lead to filling and death from suffocation of attached and inactive forms of benthos. In surviving fish, mollusks and crustaceans, the growth rate is reduced due to the deterioration of feeding and breathing conditions. The species composition of the benthic community often changes.

When organizing a system for controlling waste discharges into the sea, the definition of dumping areas, taking into account the properties of materials and the characteristics of the marine environment, is of decisive importance. The necessary criteria for solving the problem are contained in the "Convention for the Prevention of Marine Pollution by Dumping of Wastes and Other Materials" (London Convention on Dumping, 1972). The main requirements of the Convention are as follows.

1. Assessment of the quantity, condition and properties (physical, chemical, biochemical, biological) of discharged materials, their toxicity, stability, tendency to accumulation and biotransformation in the aquatic environment and marine organisms. Using the possibilities of neutralization, neutralization and recycling of waste.

2. Selection of areas of discharge, taking into account the requirements of maximum dilution of substances, their minimum spread beyond the discharge, a favorable combination of hydrological and hydrophysical conditions.

3. Ensuring remoteness of discharge areas from fish feeding and spawning areas, from habitats of rare and sensitive species of hydrobionts, from recreation and economic use areas.

Technogenic radionuclides. The ocean is characterized by natural radioactivity due to the presence in it of 40 K, 87 Rb, 3 H, 14 C, as well as radionuclides of the uranium and thorium series. More than 90% of the natural radioactivity of ocean water is 40 K, which is 18.5-10 21 Bq. The unit of activity in the SI system is the becquerel (Bq), equal to the activity of an isotope in which 1 decay event occurs in 1 s. Previously, the off-system unit of radioactivity, curie (Ci), was widely used, corresponding to the activity of an isotope in which 3.7-10 10 decay events occur in 1 s.

Radioactive substances of technogenic origin, mainly fission products of uranium and plutonium, began to enter the ocean in large quantities after 1945, i.e., from the beginning of nuclear weapons testing and the widespread development of the industrial production of fissile materials and radioactive nuclides. Three groups of sources are identified: 1) testing of nuclear weapons, 2) dumping of radioactive waste, 3) accidents of ships with nuclear engines and accidents associated with the use, transportation and production of radionuclides.

Many radioactive isotopes with a short half-life, although found in water and marine organisms after an explosion, are almost never found in global radioactive fallout. Here, first of all, 90 Sr and 137 Cs are present with a half-life of about 30 years. The most dangerous radionuclide from the unreacted remains of nuclear charges is 239 Pu (T 1/2 = 24.4-10 3 years), which is very poisonous as a chemical substance. As fission products 90 Sr and 137 Cs decay, it becomes the main contaminant. By the time of the moratorium on atmospheric tests of nuclear weapons (1963), the activity of 239 Pu in the environment was 2.5-10 16 Bq.

A separate group of radionuclides is formed by 3 H, 24 Na, 65 Zn, 59 Fe, 14 C, 31 Si, 35 S, 45 Ca, 54 Mn, 57.60 Co and others arising from the interaction of neutrons with structural elements and the environment. The main products of nuclear reactions with neutrons in the marine environment are the radioisotopes of sodium, potassium, phosphorus, chlorine, bromine, calcium, manganese, sulfur, and zinc, which originate from elements dissolved in sea water. This is induced activity.

Most of the radionuclides that enter the marine environment have analogs that are constantly present in water, such as 239 Pu, 239 Np, 99 T C) transplutonium are not typical for the composition of sea water, and the living matter of the ocean must adapt to them anew.

As a result of the processing of nuclear fuel, a significant amount of radioactive waste appears in liquid, solid and gaseous forms. The bulk of the waste is radioactive solutions. Given the high cost of processing and storing concentrates in special storage facilities, some countries choose to dump waste into the ocean with river runoff or dump it in concrete blocks on the bottom of deep ocean trenches. For the radioactive isotopes Ar, Xe, Em and T, reliable methods of concentration have not yet been developed, so they can enter the oceans with rain and sewage.

During the operation of nuclear power plants on surface and underwater vessels, of which there are already several hundred, about 3.7-10 16 Bq with ion-exchange resins, about 18.5-10 13 Bq with liquid waste and 12.6-10 13 Bq due to leaks. Emergencies also make a significant contribution to ocean radioactivity. To date, the amount of radioactivity introduced into the ocean by man does not exceed 5.5-10 19 Bq, which is still small compared to the natural level (18.5-10 21 Bq). However, the concentration and unevenness of radionuclide fallout creates a serious danger of radioactive contamination of water and hydrobionts in certain areas of the ocean.

2 Anthropogenic ocean ecology–new scientific direction in oceanology. As a result of anthropogenic impact, additional environmental factors appear in the ocean that contribute to the negative evolution of marine ecosystems. The discovery of these factors stimulated the development of extensive fundamental research in the World Ocean and the emergence of new scientific directions. Among them is the anthropogenic ecology of the ocean. This new direction is designed to study the mechanisms of organisms' response to anthropogenic impacts at the level of a cell, organism, population, biocenosis, ecosystem, as well as to study the features of interactions between living organisms and the environment in changed conditions.

The object of study of the anthropogenic ecology of the ocean is the change in the ecological characteristics of the ocean, primarily those changes that are important for the ecological assessment of the state of the biosphere as a whole. These studies are based on a comprehensive analysis of the state of marine ecosystems, taking into account geographic zoning and the degree of anthropogenic impact.

The anthropogenic ecology of the ocean uses the following methods of analysis for its own purposes: genetic (assessment of carcinogenic and mutagenic hazards), cytological (study of the cellular structure of marine organisms in a normal and pathological state), microbiological (study of the adaptation of microorganisms to toxic pollutants), ecological (knowledge of the patterns of formation and development of populations and biocenoses in specific habitat conditions in order to predict their state in changing environmental conditions), ecological and toxicological (study of the response of marine organisms to the effects of pollution and determination of critical concentrations of pollutants), chemical (study of the entire complex of natural and anthropogenic chemicals in marine environment).

The main task of the anthropogenic ecology of the ocean is to develop scientific bases for determining the critical levels of pollutants in marine ecosystems, assessing the assimilation capacity of marine ecosystems, normalizing anthropogenic impacts on the World Ocean, as well as creating mathematical models of environmental processes to predict environmental situations in the ocean.

Knowledge about the most important ecological phenomena in the ocean (such as production and destruction processes, the passage of biogeochemical cycles of pollutants, etc.) is limited by a lack of information. This makes it difficult to predict the ecological situation in the ocean and the implementation of environmental protection measures. At present, of particular importance is the implementation of ecological monitoring of the ocean, the strategy of which is focused on long-term observations in certain areas of the ocean with the aim of creating a data bank covering the global transformation of ocean ecosystems.

3 The concept of assimilation capacity. According to the definition of Yu. A. Israel and A. V. Tsyban (1983, 1985), the assimilation capacity of the marine ecosystem A i for this pollutant i(or the sum of pollutants) and for the m-th ecosystem is the maximum dynamic capacity of such a quantity of pollutants (in terms of the entire zone or volume unit of the marine ecosystem) that can be accumulated, destroyed, transformed (by biological or chemical transformations) per unit of time ) and removed due to the processes of sedimentation, diffusion or any other transfer outside the volume of the ecosystem without disturbing its normal functioning.

The total removal (A i) of a pollutant from a marine ecosystem can be written as

where K i is the safety factor reflecting the environmental conditions of the pollution process in different zones of the marine ecosystem; τ i - residence time of the pollutant in the marine ecosystem.

This condition is met at , where C 0 i is the critical concentration of the pollutant in sea water. Hence, the assimilation capacity can be estimated by formula (1) at ;.

All quantities included in the right side of equation (1) can be directly measured from the data obtained in the process of long-term integrated studies of the state of the marine ecosystem. At the same time, the sequence of determining the assimilation capacity of a marine ecosystem for specific pollutants includes three main stages: 1) calculating the balances of the mass and lifetime of pollutants in the ecosystem, 2) analyzing the biotic balance in the ecosystem, and 3) assessing the critical concentrations of the impact of pollutants (or environmental MPCs). ) on the functioning of the biota.

To address the issues of environmental regulation of anthropogenic impacts on marine ecosystems, the calculation of the assimilation capacity is the most representative, since it takes into account the assimilation capacity, the maximum permissible environmental load (MPEL) of the pollutant reservoir is calculated quite simply. So, in the stationary mode of pollution of the reservoir, PDEN will be equal to the assimilation capacity.

4 Conclusions from the assessment of the assimilation capacity of the marine ecosystem by pollutants on the example of the Baltic Sea. Using the example of the Baltic Sea, the values of assimilation capacity for a number of toxic metals (Zn, Сu, Pb, Cd, Hg) and organic substances (PCBs and BP) were calculated (Izrael, Tsyban, Venttsel, Shigaev, 1988).

The average concentrations of toxic metals in sea water turned out to be one or two orders of magnitude lower than their threshold doses, while the concentrations of PCBs and BP were only an order of magnitude lower. Hence, the safety factors for PCBs and BP turned out to be lower than for metals. At the first stage of the work, the authors of the calculation, using the materials of long-term ecological studies in the Baltic Sea and literary sources, determined the concentrations of pollutants in the components of the ecosystem, the rates of biosedimentation, the fluxes of substances at the boundaries of the ecosystem, and the activity of microbial destruction of organic substances. All this made it possible to draw up balances and calculate the “lifetime” of the considered substances in the ecosystem. The "lifetime" of metals in the Baltic ecosystem turned out to be quite short for lead, cadmium and mercury, somewhat longer for zinc, and maximum for copper. The "lifetime" of PCBs and benzo(a)pyrene is 35 and 20 years, which determines the need to introduce a system of genetic monitoring of the Baltic Sea.

At the second stage of research, it was shown that the most sensitive element of the biota to pollutants and changes in the ecological situation are planktonic microalgae, and therefore, the process of primary production of organic matter should be chosen as the “target” process. Therefore, the threshold doses of pollutants established for phytoplankton are applied here.

Estimates of the assimilation capacity of the zones of the open part of the Baltic Sea show that the existing sink of zinc, cadmium and mercury, respectively, is 2, 20 and 15 times less than the minimum values of the assimilation capacity of the ecosystem for these metals and does not pose a direct danger to primary production. At the same time, the supply of copper and lead already exceeds their assimilation capacity, which requires the introduction of special measures to limit the flow. The current supply of BP has not yet reached the minimum value of the assimilation capacity, while PCBs exceed it. The latter points to the urgent need to further reduce PCB discharges into the Baltic Sea.

In childhood ocean I associate with something mighty and great. Three years ago I visited the island and saw the ocean with my own eyes. He attracted my gaze with his strength and immense beauty, which cannot be measured by the human eye. But not everything is as beautiful as it seems at first glance. There are quite a lot of global problems in the world, one of which is ecological problem, more precisely, ocean pollution.

Major ocean pollutants in the world

The main problem is the chemicals that are thrown away by various enterprises. The main contaminants are:

Oil.
Petrol.
Pesticides, fertilizers and nitrates.
Mercury and other harmful chemicals .

Oil is the biggest scourge for the ocean.

As we saw, the first on the list is oil, and this is no coincidence. Oil and petroleum products are the most common pollutants in the oceans. Already at the start 80syears thrown into the ocean every year 15.5 million tons of oil, and this 0.22% of global production. Oil and oil products, gasoline as well as pesticides, fertilizers and nitrates, even mercury and other harmful chemical compounds - all of them during emissions from enterprises enter the oceans. All of the above leads the ocean to the fact that pollution forms its fields to the maximum intensively, and especially in areas of oil production.

Pollution of the World Ocean - what it can lead to

The most important thing to understand is that hocean pollution is an action that is directly related to a person. Accumulated perennial chemicals and toxins are already affecting the development of pollutants in the ocean, and these in turn have a negative impact on marine organisms and the human body. The consequences to which the actions and inaction of people lead are horrendous. Destruction of many species of fish as well as other inhabitants of the ocean waters- this is not all that we get because of the indifferent attitude of man to the Ocean. We should think that the loss can be much, much more than we might think. Do not forget that the oceans have a very important role, he has planetary functions, the ocean is powerful thermal regulator and moisture circulation Earth and the circulation of its atmosphere. Pollution can lead to an irreparable change in all these characteristics. The worst thing that such changes are already observed today. A person can do a lot, he can both save nature and destroy it. We should think about how humanity has already harmed nature, we must understand that much is already irreparable. Every day we become colder and more callous to our home, to our Earth. But we and our descendants still live on it. Therefore we must cherish World Ocean!

Contrary to popular belief, the ocean is the most suitable place to dump some of the waste of human activity. If this process is carefully controlled, it does not harm the life of the ocean.

W. Bascom

August 1974

Introduction.

Pollution of the oceans.

A huge mass of waters of the World Ocean forms the climate of the planet, serves as a source of precipitation. More than half of the oxygen enters the atmosphere from the ocean, and it also regulates the content of carbon dioxide in the atmosphere, as it is able to absorb its excess; 85 million tons of fish are caught annually in the World Ocean.

The world's oceans are both protein for the starving, of which there are millions on earth, and new medicines for the sick, water for deserts, energy and minerals for industry, and places of rest.

Perhaps not a single problem is now causing such lively discussions among mankind as the problem of pollution of the oceans. Recent decades have been marked by increased anthropogenic impacts on marine ecosystems as a result of pollution of the seas and oceans. The spread of many pollutants has become local, regional and even global. Therefore, pollution of the seas, oceans and their biota has become a major international problem, and the need to protect the marine environment from pollution is dictated by the requirements of the rational use of natural resources. No one will dispute the wisdom of protecting the ocean and the life developed in it from the harm that waste emissions can cause. Most importantly, we do not have the right to sit idle waiting for a final decision on what "pollution" is, as we run the risk of being faced with the fact of pollution, which no one tried to prevent. This is all the more serious because the ocean cannot be cleansed like a river or a lake.

When discussing the problem of ocean pollution, it is important to distinguish between three types of questions: (1) What substances, in what quantities, and by what route enter the ocean? Do they enter the ocean with river runoff, from discharge channels, from the sinking of tankers and other ships, or are they carried by the wind to the sea? (2) What happens to pollutants when they enter the ocean? How quickly do they dilute to harmless concentrations? How do they accumulate in food chains? How quickly do harmful organic pollutants like oil, DDT and similar substances break down? (3) What is the significance of this or that level of pollution for the processes occurring in the ocean? Is the growth or reproduction of marine organisms suppressed? Is the contaminant concentrated in marine organisms in such quantities that it poses a risk to human health when seafood is eaten?

Some of the changes in the ocean environment caused by human activity are already irreversible. For example, dammed rivers carry much less fresh water and sediment. Ports at estuaries change the flow of water into the natural environment.

How clean should the ocean be and how much should man try to save the environment? The problem is to determine what is optimal for society and achieve it at the lowest cost.

Disposal of waste automatically implies pollution Anything living or non-living that reduces the quality of life by its excess is pollution. Most of the substances called pollutants are already present in the ocean in huge quantities: bottom sediment material, metals, salts and all kinds of organics. The ocean can withstand an even greater load of these substances, but the question is how much: to what extent the ocean can withstand this load without negative consequences.

In 1973, one of the approaches to this issue was proposed: “Water is considered polluted if, due to its insufficiently high qualities, it cannot meet the highest requirements for its use in the present or future.” The highest demands are water sports and seafood production, as well as keeping life at sea at a constant level.

To maintain an acceptable level of ocean water quality, it is necessary to consider the main types of likely pollutants resulting from human activities. One is faecal sewage (75 g dry weight solid per person per day), which, after various treatments, ends up in the ocean as "urban wastewater". In addition, a stream of waste from many industrial enterprises is sent to the ocean. Typically, these wastes are pre-treated to remove components that are likely to be hazardous, while the rest of the wastewater is piped into the ocean. Dumping from barges on the high seas is a means of getting rid of soil excavated during dredging (when deepening passages for ships), feces, and chemical waste. Thermal (thermal) pollution is represented by heated water from coastal thermal power plants, as well as cold water coming from berths where gas carrier ships are unloaded. In addition, garbage is dumped from ships, as well as ballast water containing oil.

These are intentional releases; however, pollutants enter the ocean in other ways. From the air comes small particles of pesticides sprayed over crops, soot particles from chimneys, exhaust gases from car and aircraft engines. From the painted hulls of ships, small amounts of toxicants are separated, the purpose of which is to prevent the fouling of ships with algae and crustaceans. As a result of forest fires, huge amounts of ash and metal oxides enter the ocean from the atmosphere. Oil spilled from tankers as a result of marine disasters and gushing during underwater drilling forms a special type of pollutant.

Also, as a result of many natural processes, substances enter the ocean that would be called pollutants if they were products of human activity. Freshwater river runoff has a devastating effect on marine organisms such as corals; in addition, they carry pollutants washed away by rain from the trees and the ground. In addition, a large amount of heavy metals, magma substances. Heat also enters the ocean as a result of volcanic eruptions. Oil seeped from the bottom of the ocean long before the appearance of man on Earth and continues to seep to this day.

PictureA. Ocean surface oil pollution

The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it. Among them are gaseous and aerosol pollutants of industrial and domestic origin. The accumulation of carbon dioxide in the atmosphere is also progressing. Further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also alarmed by the ongoing pollution of the World Ocean with oil and oil products, which has already reached 1/5 of its total surface. Oil pollution of this size can cause significant disruption of gas and water exchange between the hydrosphere and the atmosphere. There is no doubt about the importance of chemical contamination of the soil with pesticides and its increased acidity, leading to the collapse of the ecosystem. In general, all the factors considered, to which a polluting effect can be attributed, have a significant impact on the processes occurring in the biosphere.

Industrial and chemical pollution

Among the pollution of various types of environment, chemical pollution of natural waters is of particular importance. Suffice it to say that a person lives only a few days without water. Therefore, let us consider in more detail the chemical pollution of natural waters. Any body of water or water source is associated with its external environment. It is influenced by the conditions for the formation of surface or underground water runoff, various natural phenomena, industry, industrial and municipal construction, transport, economic and domestic human activities. The consequence of these influences is the introduction of new, unusual substances into the aquatic environment - pollutants that degrade water quality.

I would now like to focus on a few human pollutants that cause the most damage to the waters of the world's oceans and describe them in more detail.

Oil and oil products.

Oil is a viscous oily liquid that is dark brown in color and has low fluorescence. Oil consists mainly of saturated aliphatic and hydroaromatic hydrocarbons. The main components of oil - hydrocarbons (up to 98%) - are divided into four classes:

1. Paraffins (alkenes) (up to 90% of the total composition) - stable substances, the molecules of which are expressed by a straight and branched chain of carbon atoms. Light paraffins have maximum volatility and solubility in water.

2. Cycloparaffins % of the total composition) saturated cyclic compounds with 5-6 carbon atoms in the ring. In addition to cyclopentane and cyclohexane, bicyclic and polycyclic compounds of this group are found in oil. These compounds are very stable and difficult to biodegrade.

3. aromatic hydrocarbons (20-40% of the total composition) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than cycloparaffins. Oil contains volatile compounds with a molecule in the form of a single ring (benzene).

4. Olefins (alkenes)- (up to 10% of the total composition) - unsaturated non-cyclic with one or two hydrogen atoms at each carbon atom in a molecule that has a straight and branched chain.

Oil and oil products have a harmful effect on many living organisms and adversely affect all links of the biological chain. Far out to sea and on the beach, one can see small balls of a tar-like substance, huge shiny spots and brown foam. More than 10 million tons of oil enters the ocean every year, and at least half of it comes from sources on land (refineries, oil filling stations). A large amount of oil enters the ocean as a result of natural seepage from the ocean floor, but it is difficult to determine exactly how much.

Between the years in the USA, the Institute for Environmental Protection and Energy noted pre-cases of water pollution by oil. Most of the recorded spills were minor and did not require special cleaning of the ocean surface. The total amount of oil spilled ranges from 8.2 million gallons in 1977 to 21.5 million gallons in 1985. There are 169 major tanker accidents in the world.

There are several ways of getting oil and oil products:

¨ discharges into the sea of washing, ballast and bilge waters from ships (23%);

¨ discharges in ports and near-port water areas, including losses during loading of tankers' bunkers (17%);

¨ Discharge of industrial waste and sewage (10%);

¨ storm drains (5%);

¨ accidents of ships and drilling rigs at sea (6%)

¨ offshore drilling (1%);

¨ atmospheric fallout (10%);

¨ river runoff in all its variety of forms (28%)

An example of the first major accident of an oil tanker is the disaster in 1967 of the tanker "Torri Canyon", whose tanks contained 117 thousand tons of crude Kuwaiti oil. Not far from Cape Cornwell, a tanker hit a reef, and as a result of holes and damage, about 100 thousand tons of oil spilled into the sea. Under the influence of the wind, powerful oil slicks reached the coast of Cornwall, crossed the English Channel and approached the coast of Brittany (France). Marine, coastal and beach ecosystems have suffered enormous damage. Since then, oil spills from accidents with ships and offshore drilling rigs have been quite common. In general, for the years as a result of accidents, about 2 million oil entered the marine environment, and from 1964 to 1971 66 thousand tons annually, from 1971 to 1976 - 116 thousand tons each, from 1976 to 1979 - 177 thousand tons each .

Over the past 30 years, about 2,000 wells have been drilled in the World Ocean, of which 1,000 have been drilled and 350 industrial wells have been drilled in the North Sea since 1964 alone. Due to minor leaks at drilling rigs, 0.1 million tons of oil are lost annually, but emergency situations are also not uncommon.

Large masses of oil from land enter the seas along rivers, with domestic and storm drains. The volume of oil pollution from this source exceeds 2 million tons of oil per year. Up to 0.5 million tons of oil annually enters the sea with the effluents of industry and oil refineries.

Oil films on the surface of the seas and oceans can interfere with the exchange of energy, heat, moisture and gases between the ocean and the atmosphere. Ultimately, the presence of an oil film on the surface of the ocean can affect not only the physicochemical and hydrobiological conditions in the ocean, but also the oxygen balance in the atmosphere.

. organic pollution

Among the soluble substances introduced into the ocean from land, not only mineral and biogenic elements, but also organic residues are of great importance for the inhabitants of the aquatic environment. The removal of organic matter into the ocean is estimated in million tons/year. Wastewater containing suspensions of organic origin or dissolved organic matter adversely affects the condition of water bodies. When settling, the suspensions flood the bottom and delay the development or completely stop the vital activity of these microorganisms involved in the process of water self-purification. When these sediments rot, harmful compounds and toxic substances, such as hydrogen sulfide, can be formed, which lead to pollution of all water in the river. The presence of suspensions also makes it difficult for light to penetrate deep into the water and slows down the processes of photosynthesis. One of the main sanitary requirements for water quality is the content of the required amount of oxygen in it. Harmful effect is exerted by all contaminants that in one way or another contribute to the reduction of oxygen content in water. Surfactants - fats, oils, lubricants - form a film on the surface of the water, which prevents gas exchange between water and the atmosphere, which reduces the degree of saturation of water with oxygen. A significant amount of organic matter, most of which is not characteristic of natural waters, is discharged into rivers along with industrial and domestic wastewater. Increasing pollution of water bodies and drains is observed in all industrial countries. Information on the content of some organic substances in industrial wastewater is provided in the figure. 3.

PictureB. organic contaminants

Due to the rapid pace of urbanization and the somewhat slow construction of sewage treatment plants or their unsatisfactory operation, water basins and soil are polluted with household waste. Pollution is especially noticeable in slow-flowing or stagnant water bodies (reservoirs, lakes). Decomposing in the aquatic environment, organic waste can become a medium for pathogenic organisms. Water contaminated with organic waste becomes almost unsuitable for drinking and other purposes. Household waste is dangerous not only because it is a source of some human diseases (typhoid fever, dysentery, cholera), but also because it requires a lot of oxygen for its decomposition. If domestic wastewater enters the reservoir in very large quantities, then the content of soluble oxygen may drop below the level necessary for the life of marine and freshwater organisms.

Inorganic pollution

The main inorganic (mineral) pollutants of fresh and marine waters are a variety of chemical compounds that are toxic to the inhabitants of the aquatic environment. These are compounds of arsenic, lead, cadmium, mercury, chromium, copper, fluorine. Most of them end up in water as a result of human activities. Heavy metals are absorbed by phytoplankton and then transferred through the food chain to more highly organized organisms. The toxic effect of some of the most common pollutants in the hydrosphere is shown in Figure 2:

PictureC. The degree of toxicity of certain substances

Degree of toxicity (note):

0 - absent;

1 - very weak;

2 - weak;

3 - strong;

4 - very strong.

In addition to the substances listed in the table, dangerous contaminants of the aquatic environment include inorganic acids and bases, which cause a wide pH range of industrial effluents (1.0 - 11.0) and can change the pH of the aquatic environment to values of 5.0 or above 8.0, while fish in fresh and sea water can exist only in the pH range of 5.0 - 8.5. Among the main sources of pollution of the hydrosphere with minerals and biogenic elements, food industry enterprises and agriculture should be mentioned. About 16 million tons of salts are annually washed out from irrigated lands. By the year 2000 it is possible to increase their mass up to 20 million tons/year. Wastes containing mercury, lead, copper are localized in separate areas off the coast, but some of them are carried far beyond the territorial waters. Mercury pollution significantly reduces the primary production of marine ecosystems, inhibiting the development of phytoplankton. Wastes containing mercury usually accumulate in the bottom sediments of bays or river estuaries. Its further migration is accompanied by the accumulation of methyl mercury and its inclusion in the trophic chains of aquatic organisms. Thus, the Minamata disease, first discovered by Japanese scientists in people who ate fish caught in the Minamata Bay, into which industrial effluents with technogenic mercury were uncontrollably discharged, became notorious.

Pesticides.

Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups:

1. Insecticides for harmful insects

2. fungicides and bactericides - to combat bacterial plant diseases

3. herbicides against weeds.

It has been found that pesticides destroying pests, they harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control.

World production of pesticides reaches 200 thousand tons per year. The relative chemical stability, as well as the nature of distribution, contributed to their entry into the seas and oceans in large volumes. The constant accumulation of organochlorine substances in water poses a serious threat to human life. It has been established that there is a certain correlation between the level of water pollution by organochlorine substances and their concentrations in the fatty tissues of fish and marine mammals.

Pesticides have been found in various areas of the Baltic, North, Irish seas, in the Bay of Biscay, off the west coast of England, Iceland, Portugal, and Spain. DDT and hexachloran have been found in significant amounts in the liver and blubber of seals and chinstrap penguins, although DDT preparations are not used in Antarctic conditions. Vapors of DDT and other organochlorine substances can concentrate on air particles or combine with aerosol droplets and in this state are transported over long distances. Another possible source of these substances in Antarctica may be ocean pollution as a result of their intensive use in the USA and Canada. Together with ocean water pesticides reach Antarctica.

Synthetic surfactants.

Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (SMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the continental waters and the marine environment. SMS contains sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: flavoring agents, bleaching agents (persulphates, perborates), soda ash, sodium silicates. Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic, cationic, amphoteric, and nonionic. The most common among the surfactants are anionic substances. They account for about 50% of all surfactants produced in the world. The presence of surfactants in industrial wastewater is associated with their use in such processes as flotation beneficiation of ores, separation of chemical technology products, production of polymers, improvement of conditions for drilling oil and gas wells, and equipment corrosion control. In agriculture, surfactants are used as part of pesticides.

Compounds with carcinogenic properties.

Carcinogenic substances are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the conditions of exposure, they can lead to growth inhibition, accelerated aging, disruption of individual development, and changes in the gene pool of organisms. The maximum amount of PAHs in modern bottom sediments of the World Ocean (more than 100 μg/km of dry matter mass) was found in tectonically active zones subject to deep thermal impact. The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel.

Heavy metals.

Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are common and highly toxic pollutants. They are widely used in many industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is very high. Large masses of these compounds enter the ocean through the atmosphere. For marine biocenoses, mercury, lead, and cadmium are the most dangerous. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 121 thousand tons of mercury, a significant part of which is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons/year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. At the same time, some bacteria convert chlorides into highly toxic methyl mercury. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population.

The owners of the Tissot chemical plant in the town of Minamata on the island of Kyushu have been dumping wastewater saturated with mercury into the ocean for many years. Coastal waters and fish were poisoned, which led to the death of local residents. Hundreds of people got severe psychoparalytic illnesses.

The victims of this ecological catastrophe, united in groups, repeatedly filed cases against Tissot, the government and local authorities. Minamata has become Japan's true "industrial Hiroshima", and the term "Minamata disease" is now widely used in medicine to refer to the poisoning of people with industrial waste.

Lead is a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Lead is actively dissipated in the environment in the course of human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines. French researchers found that the bottom of the Atlantic Ocean is exposed to lead from land at a distance of up to 160 km from the coast and at a depth of up to 1610 m. A higher concentration of lead in the upper layer of bottom sediments than in deeper layers indicates that this is the result of economic human activity, and not a consequence of a long natural process.

Household waste

Liquid and solid domestic wastes (faeces, sediment sludge, garbage) enter the seas and oceans through rivers, directly from land, as well as from ships and barges. different directions.

In the surface layer of the sea, bacteria develop in huge quantities - useful, playing an important role in the life of the neuston and the entire sea, and pathogenic, pathogens of gastrointestinal and other diseases.

Household waste is dangerous not only because it is a carrier of human diseases (mainly of the intestinal group - typhoid fever, dysentery, cholera), but also because it contains a significant amount of oxygen-absorbing substances. Oxygen supports life in the sea, it is a necessary element in the process of decomposition of organic substances entering the aquatic environment. Municipal waste entering the water in very large quantities can significantly reduce the content of soluble oxygen.

In recent decades, plastic products (synthetic films and containers, plastic nets) have become a special type of solid waste polluting the oceans. These materials are lighter than water, and therefore float on the surface for a long time, polluting the sea coast. Plastic waste poses a serious danger to shipping: entangling the propellers of ships, clogging the pipelines of the cooling system of marine engines, they often cause shipwrecks.

There are known cases of the death of large marine mammals due to mechanical blockage of the lungs with pieces of synthetic packaging.

The seas, and especially their coastal parts, are polluted by fan and household sewage from ships. Their number is constantly increasing, as the intensity of navigation increases and ships become more and more comfortable. The amount of water consumption on passenger ships is approaching the indicators of large cities and is 300-400 liters per person per day.

In the North Sea, there is a real threat of the death of fauna and flora due to pollution by sewage carried from the mainland by rivers. The coastal regions of the North Sea are very shallow; ebbs and flows in it are insignificant, which also does not contribute to the self-purification of the sea. In addition, on its banks there are countries with a high population density, highly developed industry, and the pollution of the area has reached an extremely high level. The environmental situation is aggravated by the fact that oil production has been intensively developing in the North Sea in recent years.

The mismanagement, predatory attitude to the riches of the World Ocean leads to a violation of the natural balance, the death of oceanic flora and fauna in some areas, and the poisoning of people with contaminated products of the sea.

thermal pollution

Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The difference does not exceed natural temperature changes and therefore does not pose a danger to most adult marine inhabitants. However, during water intake, eggs, larvae, and juveniles living in coastal waters are sucked in. They pass through the power plant along with the cooling water, where they are suddenly exposed to high temperature, reduced pressure, which is fatal to them. The area of heated water spots in coastal areas can reach 30 square meters. km. For this and other reasons, it would be expedient to place power plants on the high seas, where water can be taken from deeper and cooler layers, less rich in living organisms. Then, if the power plants are nuclear, the danger of the consequences of a possible accident would also be reduced. If the power plants run on oil and coal, then the fuel could be delivered directly to the plant by ships, while the coastline could be used for non-industrial purposes. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since with increasing temperature, the activity of aerobic bacteria that decompose organic matter increases. The species diversity of phytoplankton and the entire flora of algae is increasing.

Dumping of waste into the sea for the purpose of disposal

(dumping).

Dumping is a term with a special meaning; it must not be confused with clogging (contamination) with debris or emissions through pipes. Discharge is the delivery of waste to the open sea and its disposal in specially designated areas. From barges exporting solid waste, the latter are dumped through bottom hatches. Liquid waste is usually pumped through a submerged pipe into the ship's turbulent wake. In addition, some waste is buried from barges in closed steel or other containers.

Most of the discharged material is suspended soil, sucked in by a dredging projectile with a receiving funnel from the bottom of the harbor and ports when the fairways are deepened. In 1968, 28 million tons of this material were dumped into the Atlantic Ocean. Relatively pure material is next in volume - this is also the soil excavated by excavators during construction, then any sediment (silt) from municipal waste, and finally industrial waste such as acids and other chemicals.

In some areas, urban waste is not flooded from barges, but is discharged into the ocean through special pipes; in other areas they are dumped into landfills or used as fertilizer, although the heavy metals in the runoff may cause adverse effects in the long term. A wide range of industrial wastes (solvents used in pharmaceutical production, waste acids of titanium dyes, alkaline solutions of oil refineries, calcium metal, layered filters, salts and chloride hydrocarbons) are dumped from time to time in different places.

What harm does the dumping of such materials cause to marine organisms? The turbidity that appears when the waste is dumped, as a rule, disappears within a day. The soil dumped in suspension covers the inhabitants of the bottom with mud in the form of a thin layer, from under which many animals get out to the surface, and some are replaced a year later by new colonies of the same organisms. Household sludges with a high content of heavy metals can be toxic, especially when combined with organic matter, an oxygen-reduced environment is formed; only a few living organisms can exist in it. In addition, the sludge may have a high bacteriological index. It is obvious that industrial waste in large volumes is hazardous to the life of the ocean and therefore should not be dumped into it.

The dumping of waste into the ocean, as such, still needs to be carefully studied. With reliable data, materials such as soils may still be allowed to be dumped into the sea, but other substances, such as chemicals, should be prohibited. When organizing a system of control over waste discharges into the sea, the definition of dumping areas, the determination of the dynamics of water pollution and bottom sediments is of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the composition of the material discharge. Deep-water areas of the seabed can be identified for this purpose on the basis of the same criteria as in the choice of sites for urban landfills - ease of use and low biological value.

Protection of the waters of the world's oceans

Man has to get rid of his waste somehow, and the ocean is the most suitable place for some of it.

Self-purification of the seas and oceans .

Self-purification of seas and oceans is a complex process in which pollution components are destroyed and included in the general circulation of substances. The ability of the sea to process hydrocarbons and other types of pollution is not unlimited. At present, many water areas have already lost the ability to self-purify. Oil, accumulated in large quantities in bottom sediments, turned some bays and bays into practically dead zones.

There is a direct relationship between the number of oil-oxidizing microorganisms and the intensity of oil pollution of sea water. The largest number of microorganisms was isolated in areas of oil pollution, while the number of bacteria growing on oil reaches a million per 1 liter. Sea water.

Along with the number of microorganisms in places of constant oil pollution, the species diversity is also growing. This, apparently, can be explained by the great complexity of the chemical composition of oil, the various components of which can be consumed only by certain types of microorganisms. The relationship between the abundance and species diversity of microorganisms, on the one hand, and the intensity of oil pollution, on the other, gives grounds to consider oil-oxidizing microorganisms as indicators of oil pollution.

Sea microorganisms function as part of a complex microbiocenosis, which reacts to foreign substances as a whole. Not many types of organisms are able to completely decompose oil. Such forms are rarely isolated from water, and the process of oil degradation is not intense. A mixed bacterial "population" breaks down oil and individual hydrocarbons more effectively.

Marine organisms that are involved in self-purification processes include molluscs. There are two groups of mollusks. The first includes mussels, oysters, scallops and some others. Their mouth opening consists of two tubes (siphons). Through one siphon, sea water is sucked in with all the particles suspended in it, which are deposited in a special apparatus of the mollusk, and through the other, purified sea water flows back into the sea. All edible particles are absorbed, and undigested large lumps are thrown out. A dense population of mussels on an area of 1 sq. m. Filters up to 200 cubic meters per day. water.

Mussels are one of the most common marine aquatic organisms. A large mollusk can pass through itself up to 70 liters. water per day and thus purify it from possible mechanical impurities and some organic compounds.

It is estimated that only in the northwestern part of the Black Sea, mussels filter more than 100 km3 of water per day. Like mussels, other marine animals also feed - bryozoans, sponges, ascidians.

In mollusks of the second group, the shell is either twisted, oval-cony shaped (rapana, littorina), or resembles a cap (sea saucer). Crawling over stones, piles, piers, plants, the bottoms of ships, they clean the huge overgrown surfaces every day.

Marine organisms (their behavior and condition) are indicators of oil pollution, i.e. they, as it were, carry out biological observation of the environment. However, marine organisms are not only passive recorders, but also direct participants in the process of natural self-purification of the environment. About 70 genera of microorganisms are known, including bacteria, fungi, yeast, which are capable of fighting with oil. They play the most important role in the decomposition of oil and hydrocarbons in the sea.

An equally significant role of microorganisms in the fight against pesticides: accumulating harmful products in themselves, bacteria signal pollution of the marine environment. That is why it is so important to find out as many of these indicator organisms as possible, to obtain extremely detailed information about their behavior in certain conditions, about their state depending on environmental conditions. As it turned out recently, the most effective macrophytes in the processing of pesticides are algae growing at shallow depths and near the coast.

In the World Ocean, the biota is still practically not disturbed: with external influences that bring the system out of a state of stable equilibrium, the equilibrium shifts in the direction in which the effect of external influence weakens.

Protection of the seas and oceans

The protection of the seas and oceans should be carried out not only physically, by conducting various studies on water purification and the introduction of new methods and methods of purification, but should also be based on laws and legal documents that define the duties of people to protect the marine environment.

In 1954, an international conference was held in London, which aimed to work out coordinated actions to protect the marine environment from oil pollution. For the first time in the history of mankind, an international legal document was adopted defining states to protect the marine environment. The 1954 International Convention for the Prevention of Marine Pollution by Oil was registered by the UN.

Further concern for the protection of the oceans found expression in four conventions adopted at the 1st UN International Conference on the Law of the Sea in Geneva in 1958: on the high seas; on the territorial sea and the contiguous zone; on the continental shelf; on fishing and protection of living resources of the sea. These conventions have legally fixed the principles and norms of maritime law.

The high seas means all parts of the sea that are not part of either the territorial seas or the internal waters of any state. The Geneva Convention on the High Seas, in order to prevent pollution and damage to the marine environment, obliges each country to develop and enforce laws prohibiting polluting the sea with oil, radioactive waste and other substances.

International conventions have played a certain role in the prevention of marine pollution, but at the same time have revealed weaknesses. In 1973, the International Conference on the Prevention of Marine Pollution was convened in London. The conference adopted the International Convention for the Prevention of Marine Pollution from Ships. The 1973 Convention provides for measures to prevent pollution of the seas not only by oil, but also by other harmful liquid substances, as well as waste (sewage, ship debris, etc.). According to the Convention, each ship must have a certificate - evidence that the hull, mechanisms and other equipment are in good condition and do not pollute the sea. Compliance with the certificates is checked by the inspection when the vessel enters the port. The Convention establishes strict standards for the oil content in the water discharged by tankers. Vessels with a displacement of more than 70,000 tons must have tanks for receiving clean ballast - it is forbidden to load oil into such compartments. In special areas, the discharge of oily water from tankers and dry cargo ships with a displacement of more than 400 tons is completely prohibited. All discharges from them should be pumped out only to coastal reception points. All transport ships are equipped with separation devices for cleaning drain waters, and tankers are equipped with devices that allow tankers to be washed without discharging oil residues into the sea. Electrochemical installations have been created for the treatment and disinfection of ship wastewater, including household wastewater.

Coastal treatment facilities, which receive waste water from ships, not only clean up pollution, but also regenerate thousands of tons of oil.

Installations are placed on ships for the destruction of sludge from engine rooms, waste and garbage emptied into floating and shore receiving facilities.

The Institute of Oceanology of the Russian Academy of Sciences has developed an emulsion method for cleaning sea tankers, which completely excludes the ingress of oil into the water area and ensures the absolute cleanliness of tankers after washing. The addition of a mixture of several surfactants to the wash water makes it possible to carry out cleaning on the tanker itself using a simple installation without discharging contaminated water or oil residues from the ship and recovering it for further use. Up to 300 tons of oil can be washed from each tanker. Tanker tanks are cleaned so that even food products can be transported in them after oil.

In the absence of such an installation, washing on a tanker can be carried out using a cleaning station, which performs a mechanized washing of containers from oil products of all grades in a closed circuit using a solution heated to 70-80 C. The treatment plant also separates oil products from sewage and ballast water received from ships, removes mechanical impurities and dehydrates oil residues, and washes rust removed from oil tanks from oil products.

In order to prevent oil leaks, the designs of oil tankers are being improved. So, supertankers with a capacity of 150 thousand tons of cargo have a double bottom. If one of them is damaged, the oil will not spill out, it will be delayed by the second outer shell.

Floating cleaning stations have been set up to clean the fuel tanks of bulk carriers. A powerful hot water plant with two boilers heats water to 80-90 C, and pumps pump it into tankers. Dirty water, together with the washed oil, is returned to the treatment plant, where three cascades of settling tanks pass. And, again heated, again, it is pumped out to the sink. At the same time, oil extracted from dirty water is used for heating.

For the systematic cleaning of port waters from accidental spills and oil pollution, floating oil skimmers and booms are used. Oil skimmers NSM-4 of increased seaworthiness in raids with a distance from the port of up to 10 nautical miles with sea waves up to are capable of cleaning the sea from floating oil products and debris along the coast and in open seas of three points and wind strength of up to four points.

Booms designed to contain accidental spills of oil products both in port waters and on the high seas are made of fiberglass, which is resistant to significant wind speeds and currents.

In some cases, it is advisable to prevent the spread of oil not by mechanical (booms), but by physical and chemical methods. For this purpose, surfactants - oil collectors - are applied along the entire perimeter of the oil slick or only from the leeward side.

In the case of a large leak, mechanical and chemical methods are used simultaneously to localize the oil slick. A preparation of a foam group has been created, which, when in contact with an oil slick, completely envelops it. After pressing, the foam can be reused as a sorbent. Such sorbents are very convenient due to the simple application technology and low cost. However, mass production of such drugs has not yet been established.

At present, sorbent agents based on plant, mineral and synthetic substances have been developed. The main requirement that is presented to them is unsinkability. Collected from the water surface, some sorbents can be reused after regeneration, while others must be disposed of. There are preparations that allow collecting up to 90% of spilled oil from the surface of the water. Subsequently, they can be used to produce bitumen and other building materials.

Another important quality that a sorbent must have is the ability to capture a large amount of oil. Foam plastics obtained on the basis of polyesters absorb an amount of oil 20 times their own weight in 5 minutes.

These substances have been successfully tested in the port of Odessa and during the liquidation of the consequences of a diesel fuel spill in wetlands. The disadvantage of them should be considered that they cannot be used when the sea is rough.

After collecting spilled oil with sorbents or mechanical means, a thin film always remains on the surface, which can be removed by dispersion, i.e., by spraying preparations onto the water surface, under the action of which the oil film breaks up. Dispersants are not extracted from the water, so the main requirement for them is their biological safety. In addition, they must retain their properties when heavily diluted with sea water. The oil film after such treatment is distributed in the water column, where it undergoes final destruction as a result of biochemical processes that cause self-purification.

An original way to clean water from spilled oil was demonstrated by American scientists in the Atlantic Ocean. A ceramic plate is lowered under the oil film to a certain depth. An acoustic unit is connected to it. Under the action of vibration, oil first accumulates in a thick layer above the place where the plate is installed, and then mixes with water and begins to flow. A high-voltage electric current, also connected to the plate, sets fire to the fountain, and the oil is completely burned. If the power of the acoustic installation is not large enough, the oil only turns into a dense mass, which is removed from the water mechanically.

To remove oil stains from the surface of coastal waters, US scientists have created a modification of polypropylene that attracts fat particles. On a catamaran boat made of this material, a kind of curtain was installed between the hulls, the ends of which hang down into the water. As soon as the boat hits the slick, the oil sticks firmly to the "curtain". It remains only to pass the polymer through the rollers of a special device that squeezes the oil into a specially prepared container.

However, despite some success in the search for effective means to eliminate oil pollution, it is too early to talk about solving the problem. It is impossible to ensure the cleanliness of the seas and oceans only by introducing even the most effective methods of cleaning up pollution. The central task that must be addressed by all interested countries together is the prevention of pollution.

Protection of marine coastal waters.

A coastal water protection zone is a territory adjacent to the water areas of objects on which a special regime is established that does not allow pollution, clogging and depletion of water. The boundaries of the coastal protected area are determined by the boundaries of the area of actual and prospective marine water use of the population and two belts of the sanitary protection zone.

The area of marine water use is organized to ensure epidemic safety and prevent cases of water use limitation due to pollution with harmful chemicals. The width of this area towards the sea is usually not less than 2 km.

In the first belt of the sanitary protection zone, it is not allowed to exceed the established normative indicators of microbial and chemical pollution as a result of wastewater discharge. In terms of coastal length and width towards the sea, the belt should be at least 10 km from the border of the water use area. The second belt of the sanitary protection zone is intended to prevent pollution of the water use area and the first belt of sanitary protection as a result of discharges from ships and industrial facilities. The boundaries of the second belt are determined by the boundaries of territorial waters for internal and external seas in accordance with the requirements of an international convention.

It is forbidden to discharge into the sea wastewater that can be used in recycling and re-water supply systems: containing waste to be disposed of, production raw materials, reagents, semi-finished products and, of course, production products in quantities exceeding the established standards for technological losses, substances for which there are no maximum allowable concentrations (MPC). It is prohibited to discharge treated industrial and domestic wastewater, including ship wastewater, within the boundaries of the water use area. The assessment of the degree and nature of organic pollution that exceeds the established standards is carried out taking into account the general sanitary situation and other direct and indirect sanitary indicators of sea water pollution.

Differentiated requirements for the composition and properties of sea water in the water use area and the first zone of the sanitary protection zone are given in table 1

In places of water intake, in swimming pools with sea water, the number of bacteria (E. coli) and enterococci should not exceed 100/l and 50/l, respectively. In places of mass bathing, the presence of staphylococci in the water is also controlled. If their number exceeds 100/l, the beaches are closed.

With systematic seasonal development and accumulation of algae, the water use area should be cleared of them.

Discharge, removal and neutralization of wastewater containing radioactive substances must be carried out in accordance with the current radiation safety standards and sanitary rules for working with radioactive substances and other sources of ionizing radiation.

Requirements for the composition and properties of sea water in the area of water use and the first belt of the sanitary protection zone

Indicators of the composition and properties of sea water

General requirements and standards of indicators

composition and properties of sea water

Water use area

1 zone of sanitary protection

floating impurities

Transparency

Biochemical oxygen demand (BOD) of water

Causative agents of infectious diseases

The number of lactose-positive bacteria of the Escherichia coli group in 1 liter of water

Harmful substances

Absence of floating substances unusual for sea water on the surface in the upper 20 cm water layer (films, oil stains, inclusions and other impurities)

The intensity of odors unusual for sea water should not exceed the perception threshold (2 points) in the absence of foreign odor and taste of sea food products.

Not less than 30 cm. If the decrease in transparency is due to local hydrophysical, topographic, hydrological and other natural and climatic factors, its value is not regulated.

It is not allowed to color sea water in a column of water of 10 cm.

Should not exceed 3.0 mg/l of oxygen at 20 degrees.

Shouldn't show up

Must not exceed 1000

Absence of floating substances and other impurities unusual for sea water on the surface

Absence of foreign smell and taste in food products of the sea.

Not regulated

Regulated in relation to the conditions of wastewater discharge

Regulated in accordance with the list of hygienic standards for marine waters

When designing and building deep-sea sewage drains into the coastal waters of the sea, choosing the place of drains and calculating the degree of mixing and dilution, the following should be taken into account: the nature and direction of coastal sea currents, the direction and strength of the prevailing winds, the magnitude of the tides and other natural factors. Design, engineering and technical and technological solutions for long-distance deep-water wastewater outlets should take into account oceanographic factors (deep currents, density and temperature stratification of water, turbulent diffusion processes, etc.) that contribute to the elimination of incoming pollution.

When calculating the required degree of purification, neutralization and disinfection, and determining the conditions for mixing and diluting effluents with sea water, hydrological data for the least favorable period and sanitary indicators of the composition and properties of coastal sea water during the period of its most intensive use are taken as initial ones. The possibility of disposal and conditions for the discharge of wastewater into the sea, as well as the choice of a site for a new facility, reconstruction, expansion or change in the technologies of enterprises are subject to mandatory coordination with the sanitary and epidemiological control authorities.

For coastal areas of seas with specific hydrological conditions and unsatisfactory sanitary, hydrophysical and topographic-hydrological features that cause stagnation or pollution concentration in coastal waters, the requirements for the first belt of the sanitary protection zone cannot take into account possible dilution with sea water.

The composition and properties of waters in the mouths of rivers flowing into the sea in the area of water use must meet the requirements for water in reservoirs used for swimming and sporting events, with the exception of indicators that depend on the natural characteristics of these waters.

Within the first zone of the sanitary protection zone, discharges from ships of sewage, the origin and composition of which are determined by the International Convention for the Prevention of Pollution from Ships of 1973, are allowed, subject to the following conditions: ; b) The discharge does not result in visible floating solids and does not change the color of the water.

In ports, port points and on ships in roadsteads, wastewater must be discharged into the city sewer through drain devices and sewage disposal vessels. Solid waste, waste and garbage must be collected in special containers on board the vessel and transported ashore for subsequent disposal and disposal.

During research, exploration and development of the natural resources of the continental plume, industrial and domestic wastewater discharges, water pollution with radioactive substances and other production wastes are prohibited. If the boundaries of the continental shelf coincide with the boundaries of the water use area, the requirements for the composition and properties of sea waters must meet the regulatory requirements for the water of the water use area.

Protection of waters from pollution during drilling and development of offshore oil and gas wells.

During the construction and operation of offshore drilling platforms, as well as drilling and development of offshore wells, it is necessary to comply with all the requirements of water legislation and international agreements to prevent pollution of sea waters.

Locations for offshore drilling platforms are selected in accordance with the rules of sanitary protection of coastal waters. On offshore drilling platforms, flooring is installed over the entire plane with a drain system into specially provided containers. Bulk materials, weighting agent and chemical reagents are delivered to the offshore platform in closed containers or in sealed containers. The washing liquid is transported in closed tanks, containers or through a mortar pipeline. Chemical reagents and bulk materials are stored in sealed containers or indoors.

Drilled cuttings are collected and transported to coastal bases and stored in coastal sludge dumps, which exclude filtration and runoff into water bodies. If sea water is used as a flushing fluid during drilling of the upper intervals of the well, then it is allowed to dump the cuttings to the bottom, provided that the water management value of the water body and the natural local habitats of aquatic organisms are preserved.

Flushing fluid, water from cooling systems, drilling wastewater are used in circulating systems. If necessary, they are subjected to special cleaning at installations mounted on an offshore drilling platform. Upon completion of well development and dismantling of drilling equipment, all remaining materials and drilling fluid are imported to onshore bases.

Drilling in the interval with a possible oil and gas show is carried out only if there is a check valve on the drill string or a device that provides shut-off of the drill pipe string.

Before development, the well is equipped with sealed wellhead devices for collecting and eliminating waste - a container for collecting liquids and a block for incinerating solid waste. In the absence of such facilities, waste is removed or pumped to collection points. The means of collection and transport must prevent waste from entering the sea.

Marine pollution control.

Marine water pollution control is carried out in Russia in accordance with the London International Conventions of 1958 and 1973, as well as with the Convention for the Prevention of Pollution of the Baltic Sea. The marine environment is monitored by the Russian Federal Service for Hydrometeorology and Environmental Monitoring. Observations of pollution of the marine environment by hydrochemical parameters are carried out in all seas on the territory of Russia. Sampling is carried out at 603 sea observation points (stations), hydrochemical work is carried out by 20 stationary and 11 shipboard laboratories. Monitoring of marine environment pollution by hydrobiological indicators is also carried out by 11 hydrobiological laboratories and groups that process more than 3,000 samples per year according to 12 indicators.

Control over the level of pollution of the seas is carried out in the following areas:

* physical, chemical and hydrobiological indicators of pollution of waters and bottom sediments, especially in health resorts and fisheries, as well as in areas of the seas subjected to intense impact (estuarine zones, offshore oil fields, ports, etc.);

* The balance of pollutants in the seas and their individual parts (bays), taking into account the processes occurring at the "atmosphere-water" interface, the decomposition and transformation of pollutants and their accumulation in bottom sediments;

* Patterns of spatial and temporal changes in the concentration of pollutants, the dependence of these changes on natural circulation processes, hydrometeorological regime and features of economic activity. This takes into account changes in water temperature, currents, wind speed and direction, the level of precipitation, atmospheric pressure, air humidity, etc.

A network of local observation points allows you to quickly determine the fields of contamination. When choosing the location of the stations, they are based on the knowledge of the hydrochemical and hydrometeorological regimes and the bottom topography in this area. All marine monitoring stations carry out synchronous observations at standard geographic horizons (0, 5, 10, 15, 20, 25, 30, 40, 50 m, etc.), including the near-bottom water layer, as well as the “property jump” layers ( density, salinity, oxygen, etc.).

Points or marine or marine pollution monitoring stations fall into three categories.

Marine stations of the 1st category (single monitoring station) are designed to quickly detect high levels of pollution in the most polluted areas near the sources of discharge and inform about it. Stations of the 1st category are located at the outflow gates of the estuarine areas, in the zones of influence of wastewater discharges from agricultural lands, oil loading bases, in the places of active offshore oil fields, in areas of great fishery or cultural and health significance.

Control over the content of pollutants and visual observation of surface contamination is carried out according to two programs - reduced and full.

Abbreviated Program assumes once per decade dissolved oxygen, oil products and one or two pollutants specific to the area.

The full program involves checking once a month (combined with observations under the reduced program) for the following parameters:

* the presence of pollutants: petroleum products, organochlorine pesticides, heavy metals (mercury, lead), phenol, detergents, as well as pollutants specific to the area;

* environmental indicators: dissolved oxygen, hydrogen sulfide, concentration of hydrogen ions, biochemical oxygen consumption for 5 days, nitrite nitrogen, nitrate nitrogen, ammonium nitrogen, total nitrogen, phosphate phosphorus, total phosphorus, silicon;

* Elements of the hydrometeorological regime: water salinity, water and air temperature, speed and direction of currents and wind, transparency, water color.

At stations of the 1st category, located directly off the coast, observations are carried out only according to a reduced program. At stations located in the open part of the reservoir, during the icing period, they are held once a season according to the full program.

Marine stations of the 2nd category (single stations or systems of stations) are used to determine the levels of pollution and the trend of their variability in the most polluted areas of the city, in ports, coastal waters of the sea and estuaries, bays, bays, as well as in the locations of industrial complexes, mining , runoff agricultural land, intensive navigation and areas of cultural and fishery importance.

Conclusion.

There may not be a single solution to the issue of all types of waste and where they are dumped, but the following proposals should help save both land and sea in the future.

1. First of all, it is necessary to define what the ocean is, distinguishing it from inland freshwater bodies and harbors, as well as shallow bays, and to develop legislation corresponding to each element of the environment. 2. It should be recognized as incorrect the assumption that everything that enters the ocean can be dangerous. Instead, it is necessary to consider what substances can cause damage, and try to avoid the formation of an excess of them in the ocean. 3. Strictly prohibit the dumping of all man-made radioactive materials, halogenated hydrocarbons (DDT and polychlorinated biphenyls) and other synthetic organic materials that are toxic and against which marine organisms have no natural defenses. 4. Water quality standards (after acceptable mixing) should be set corresponding to thresholds above which marine life is impaired; in this case, a safety factor of at least ten must be ensured. 5. International cooperation should be developed in the direction of prohibiting the discharge of garbage or oil from ships, as well as the discharge of ballast water. 6. It is necessary to identify deep-water places of the ocean with a slow current, where certain wastes can be dumped, causing minimal damage to the environment. 7. It is essential that every waste disposal facility investigate how a particular pollutant will affect the adjacent ocean waters. 8. All new research into the effects of pollutants on the ocean and its life should be encouraged. 9. It is necessary to predict the emergence of new pollutants as the production of new chemical compounds develops in large volumes.

A more rational basis for making decisions about how to recycle and dispose of waste needs to be developed. No oceanographer wants hazardous waste to accumulate where he works or to have this waste accumulate on land where he lives. However, since the waste needs to find a place anyway, it would be preferable to make a choice based on knowledge of all factors.

The protection of nature, and water resources in particular, is the task of our century, a problem that has become a social one. Again and again we hear about the danger threatening the aquatic environment, but so far many of us consider it an unpleasant, but inevitable product of civilization and believe that we will still have time to cope with all the difficulties that have come to light. However, the impact of man on the aquatic environment has assumed alarming proportions. To fundamentally improve the situation, purposeful and thoughtful actions will be needed. A responsible and effective policy towards the aquatic environment will be possible only if we accumulate reliable data on the current state of the environment, substantiated knowledge about the interaction of important environmental factors, if we develop new methods to reduce and prevent the harm caused to Nature by Man. It is the development, calculation and implementation of modern, reliable and highly efficient wastewater treatment methods that this course work is devoted to.

A reasonable, non-emotional approach to the question of what materials can be dumped into the ocean without causing serious damage to its livelihoods will affect the purity of its waters and save public funds.

Bibliography

1. Ocean science; Moscow; 1981

2. The ocean itself and for us”; Moscow; 1982

3. Biology of the sea; R. Kerington; Leningrad; 1966

4. At the crossroads of ecology; ; 1985

5. Ecology, environment and man; ; Moscow 1998.

6. Environmental protection; ; Moscow "Higher School"; 1991

7. Environmental protection; ; Leningrad Gidrometeoizdat”; 1991

8. Volotskov and the use of wastewater from galvanic industries. M.: Chemistry, 1983.

9. Buchilo E. Wastewater treatment of pickling and galvanic departments. Moscow: Energy, 1977.

10. Kostyuk of wastewater from machine-building enterprises. L.: Chemistry, 1990.

11. Yakovlev industrial wastewater. Moscow: Stroyizdat, 1979.

12. Koganovsky and the use of waste water in industrial water supply. Moscow: Chemistry, 1983.

13. Industrial wastewater treatment. Ed. Kravets: Technique, 1974.

þ Introduction 1

þ Industrial and chemical pollution 4

1.1 Oil and oil products 5

1.2 Organic compounds 7

1.3 Inorganic compounds 9

1.4 Pesticides 10

1.5 Synthetic surfactants 11

1.6 Compounds with carcinogenic properties 12

1.7 Heavy metals 12

1.8 Household waste 13

1.9 Thermal pollution 14

1.10 Waste dumping into the ocean (Dumping) 15

þ Protection of the waters of the world's oceans 17

2.1 Self-purification of the seas 17

2.2 Protection of the seas and oceans, cleaning methods 19

2.3 Legislation for the protection of the world's oceans 20

2.4 Methods for cleaning water from oil 21

2.5 Requirements for the composition of sea water 22

2.6 Protection of marine coastal waters 24

2.7 Protection of waters from pollution during drilling

wells for oil and gas 26

2.8 Marine pollution control 27

þ Conclusion 29

þ Bibliography 31

Recently, mankind has polluted the ocean to such an extent that even now it is difficult to find places in the World Ocean where traces of human activity would not be observed. The problem associated with the pollution of the waters of the oceans is one of the most important problems facing humanity today.

The most dangerous types of pollution: oil pollution and oil products, radioactive substances, industrial and domestic wastewater and, finally, chemical fertilizer (pesticides) effluents.

Pollution of the waters of the oceans has taken catastrophic proportions in recent decades. This was largely facilitated by the erroneous widespread opinion about the unlimited possibilities of the waters of the World Ocean for self-purification. Many understood this to mean that any waste and garbage in any quantity in the waters of the ocean is subjected to biological processing without harmful consequences for the composition of the waters themselves. As a result, individual seas and sections of the oceans have become, in the words of Jacques Yves Cousteau, "natural sewage pits." He points out that “the sea has become a sewer into which all the pollutants carried by poisoned rivers, which wind and rain collect in our poisoned atmosphere, flow; all those pollutants discharged by poisoners such as oil tankers. Therefore, one should not be surprised if, little by little, life leaves this sewage pit.

Of all types of pollution, oil pollution is the greatest danger to the oceans today. According to estimates, from 6 to 15 million tons of oil and oil products enter the World Ocean annually. Here, first of all, it is necessary to note the losses of oil associated with its transportation by tankers. It is known that after unloading oil, in order to give the tanker the necessary stability, its tanks are partially filled with ballast water. Until recently, the discharge of ballast water with oil residues was most often carried out on the high seas. Only a very few tankers are equipped with special ballast tanks which are never filled with oil but designed specifically for ballast water.

According to the US National Academy of Sciences, up to 28% of the total amount of incoming oil enters the seas in this way.

The second way is the influx of oil products with atmospheric precipitation (after all, light fractions of oil from the sea surface evaporate and enter the atmosphere). According to the US Academy of Sciences, about 10% of the total amount of oil enters the World Ocean in this way.

Finally, if we add (practically not subject to accounting) untreated wastewater from oil refineries and oil depots located on the coasts and in ports (more than 500 thousand tons of oil products enter the sea annually in the United States), then it is easy to imagine what a threatening situation has been created with oil pollution.

Pollution with sewage waste from industrial and domestic waters is one of the most massive types of pollution of the waters of the oceans. Almost all economically developed countries are guilty of this type of pollution. Until recently, for the vast majority of industrial enterprises, rivers and seas were the place of discharge of waste effluents. Unfortunately, sewage treatment has kept pace with economic development and population growth in only a very few countries. The chemical, pulp and paper, textile and metallurgical industries are especially guilty of severe water pollution.

Water bodies and mine waters are heavily polluted due to the recent increase in the new method of coal mining - hydraulic mining, in which a large number of small particles of coal are carried out along with waste water.

Discharges from pulp and paper mills, which usually have auxiliary production of sulfite, chlorine, lime and other products, have a harmful effect, the effluents of which also heavily pollute and poison sea water bodies.

Almost untreated waste water from any industry poses a threat to the waters of the oceans.

Wastes from domestic waters, which include runoff from food enterprises, household sewage, detergents and runoff from agricultural land, also make their “contribution” to the pollution of the seas.

Food industry waste includes wastewater from butter, cheese and sugar factories.

The use of synthetic detergents, the so-called detergents, brings great harm to marine waters. In all industrialized countries there is an intensive growth in the production of detergents. All detergents usually form a stable foam when a relatively small amount of the substance is added to the water. Detergents do not lose their ability to foam even after passing through treatment facilities. Therefore, the reservoirs where wastewater enters are covered with foam clubs. Detergents are highly toxic and resistant to biodegradation processes, they are difficult to clean, do not settle and are not destroyed when diluted with clean water. True, in recent years, Germany, and after it, some other countries began to produce rapidly oxidizing detergents. A special place is occupied by runoff from agricultural land. This type of poisoning of the seas and oceans is associated primarily with the use of pesticides - chemicals used to kill insects, small rodents and other pests.

Among pesticides, organochlorine pesticides, mainly DDT, are of particular danger to marine water bodies. Moreover, pesticides enter the marine environment in two ways, both with wastewater from agricultural areas and from the atmosphere. Up to 50% of pesticides sprayed in agricultural areas never reach the plants they are intended to protect and are blown into the atmosphere. DDT has been found on dust particles in areas far from pesticide spraying areas. Precipitation carries pesticides from the atmosphere to the marine environment. DDT is found in the tissues of Antarctic penguins and polar bears in the Arctic, far from areas where harmful insects are exterminated. An analysis of the Antarctic snow cover showed that about 2,300 tons of pesticides settled on the surface of this continent, which is very remote from developed countries. It should be noted one more negative property of many pesticides, including DDT. They are actively absorbed by oil and oil products. Oil slicks and bunks of fuel oil absorb DDT and chlorinated hydrocarbons, which do not dissolve in water and do not settle to the bottom, resulting in their concentration becoming higher than in the original solution applied for spraying. As a result, one type of sea water pollution enhances the action of another. The toxicity of pesticides increases at higher sea water temperatures.

The use of mineral fertilizers with a high content of phosphorus and nitrogen, the so-called phosphates and nitrates, often also has a detrimental effect on sea water.

When the amount of nitrogen fertilizer applied is too high, the nitrogen combines with fermenting organic matter to form nitrates, which kill river and marine life. Therefore, for example, the Japanese government banned the use of nitrogenous fertilizers in rice fields.

Heavy metals, such as mercury and cadmium, which are very common among industrial waste, pose a great threat to marine fauna and human health. It has been established that almost 50% of the world's mercury production, which is about 5 thousand tons, enters the World Ocean in various ways. Especially a lot of it gets into sea waters along with the discharge of industrial wastewater. For example, due to the discharge of water by the enterprises of the pulp and paper industry in a number of countries.

Western Europe a few years ago, mercury was found in fish and seabirds off the coast of Scandinavia.

The degree of pollution of the waters of the World Ocean is also high with household items of mass consumption (plastic bottles, cans, beer cans, etc.).

It is estimated that there are about 35 million empty plastic bottles floating around in the North Pacific alone. The 90 million tourists visiting the Italian and French Mediterranean coasts every year have left behind tons of plastic cups, bottles, plates and other everyday items in the seawater.

All over the world, the volume of wastewater from industrial enterprises discharged into rivers and seas continues to increase steadily due to the growth of industry. The state of the issue with wastewater treatment continues to be extremely unsatisfactory.

Skorodumova O.A.

Introduction.

Our planet could well be called Oceania, since the area occupied by water is 2.5 times the land area. Oceanic waters cover almost 3/4 of the surface of the globe with a layer about 4000 m thick, making up 97% of the hydrosphere, while land waters contain only 1%, and only 2% are bound in glaciers. The oceans, being the totality of all the seas and oceans of the Earth, have a huge impact on the life of the planet. A huge mass of ocean water forms the climate of the planet, serves as a source of precipitation. More than half of the oxygen comes from it, and it also regulates the content of carbon dioxide in the atmosphere, as it is able to absorb its excess. At the bottom of the World Ocean there is an accumulation and transformation of a huge mass of mineral and organic substances, therefore the geological and geochemical processes occurring in the oceans and seas have a very strong influence on the entire earth's crust. It was the Ocean that became the cradle of life on Earth; now it is home to about four-fifths of all living beings on the planet.

Judging by the photographs taken from space, the name “Ocean” would be more suitable for our planet. It has already been said above that 70.8% of the entire surface of the Earth is covered with water. As you know, there are 3 main oceans on Earth - the Pacific, Atlantic and Indian, but the Antarctic and Arctic waters are also considered oceans. Moreover, the Pacific Ocean is larger than all the continents combined. These 5 oceans are not isolated water basins, but a single oceanic massif with conditional boundaries. Russian geographer and oceanographer Yuri Mikhailovich Shakalsky called the entire continuous shell of the Earth - the World Ocean. This is the modern definition. But, besides the fact that once all the continents rose from the water, in that geographical era, when all the continents had already basically formed and had outlines close to modern ones, the World Ocean took possession of almost the entire surface of the Earth. It was a global flood. Evidence of its authenticity is not only geological and biblical. Written sources have come down to us - Sumerian tablets, transcripts of the records of the priests of Ancient Egypt. The entire surface of the Earth, with the exception of some mountain peaks, was covered with water. In the European part of our mainland, the water cover reached two meters, and in the territory of modern China - about 70 - 80 cm.

resources of the oceans.

In our time, the “epoch of global problems”, the World Ocean plays an increasingly important role in the life of mankind. Being a huge pantry of mineral, energy, plant and animal wealth, which - with their rational consumption and artificial reproduction - can be considered practically inexhaustible, the Ocean is able to solve one of the most pressing problems: the need to provide a rapidly growing population with food and raw materials for a developing industry, danger of an energy crisis, lack of fresh water.

The main resource of the World Ocean is sea water. It contains 75 chemical elements, among which are such important ones as uranium, potassium, bromine, magnesium. And although the main product of sea water is still table salt - 33% of world production, magnesium and bromine are already mined, methods for obtaining a number of metals have long been patented, among them copper and silver, which are necessary for industry, the reserves of which are steadily depleted, when, as in oceanic their waters contain up to half a billion tons. In connection with the development of nuclear energy, there are good prospects for the extraction of uranium and deuterium from the waters of the World Ocean, especially since the reserves of uranium ores on earth are decreasing, and in the Ocean there are 10 billion tons of it, deuterium is generally practically inexhaustible - for every 5000 atoms of ordinary hydrogen there is one heavy atom. In addition to the isolation of chemical elements, sea water can be used to obtain fresh water necessary for humans. Many commercial desalination methods are now available: chemical reactions are used to remove impurities from water; salt water is passed through special filters; finally, the usual boiling is performed. But desalination is not the only way to obtain potable water. There are bottom sources that are increasingly being found on the continental shelf, that is, in areas of the continental shelf adjacent to the shores of land and having the same geological structure as it. One of these sources, located off the coast of France - in Normandy, gives such an amount of water that it is called an underground river.

The mineral resources of the World Ocean are represented not only by sea water, but also by what is “under water”. The bowels of the ocean, its bottom are rich in mineral deposits. On the continental shelf there are coastal placer deposits - gold, platinum; there are also precious stones - rubies, diamonds, sapphires, emeralds. For example, near Namibia, diamond gravel has been mined underwater since 1962. On the shelf and partly on the continental slope of the Ocean, there are large deposits of phosphorites that can be used as fertilizers, and the reserves will last for the next few hundred years. The most interesting type of mineral raw material of the World Ocean is the famous ferromanganese nodules, which cover vast underwater plains. Concretions are a kind of "cocktail" of metals: they include copper, cobalt, nickel, titanium, vanadium, but, of course, most of all iron and manganese. Their locations are well known, but the results of industrial development are still very modest. But the exploration and production of oceanic oil and gas on the coastal shelf is in full swing, the share of offshore production is approaching 1/3 of the world production of these energy carriers. On an especially large scale, deposits are being developed in the Persian, Venezuelan, Gulf of Mexico, and in the North Sea; oil platforms stretched off the coast of California, Indonesia, in the Mediterranean and Caspian Seas. The Gulf of Mexico is also famous for the sulfur deposit discovered during oil exploration, which is melted from the bottom with the help of superheated water. Another, as yet untouched pantry of the ocean are deep crevices, where a new bottom is formed. So, for example, hot (more than 60 degrees) and heavy brines of the Red Sea depression contain huge reserves of silver, tin, copper, iron and other metals. The extraction of materials in shallow water is becoming more and more important. Around Japan, for example, underwater iron-bearing sands are sucked out through pipes, the country extracts about 20% of coal from sea mines - an artificial island is built over rock deposits and a shaft is drilled that reveals coal seams.

Many natural processes occurring in the World Ocean - movement, temperature regime of waters - are inexhaustible energy resources. For example, the total power of the tidal energy of the Ocean is estimated at 1 to 6 billion kWh. This property of ebbs and flows was used in France in the Middle Ages: in the 12th century, mills were built, the wheels of which were driven by a tidal wave. Today in France there are modern power plants that use the same principle of operation: the rotation of the turbines at high tide occurs in one direction, and at low tide - in the other. The main wealth of the World Ocean is its biological resources (fish, zool.- and phytoplankton and others). The biomass of the Ocean has 150 thousand species of animals and 10 thousand algae, and its total volume is estimated at 35 billion tons, which may well be enough to feed 30 billion! human. Catching 85-90 million tons of fish annually, it accounts for 85% of the used marine products, shellfish, algae, humanity provides about 20% of its needs for animal proteins. The living world of the Ocean is a huge food resource that can be inexhaustible if used properly and carefully. The maximum fish catch should not exceed 150-180 million tons per year: it is very dangerous to exceed this limit, as irreparable losses will occur. Many varieties of fish, whales, and pinnipeds have almost disappeared from ocean waters due to immoderate hunting, and it is not known whether their population will ever recover. But the population of the Earth is growing at a rapid pace, increasingly in need of marine products. There are several ways to increase its productivity. The first is to remove from the ocean not only fish, but also zooplankton, part of which - Antarctic krill - has already been eaten. It is possible, without any damage to the Ocean, to catch it in much larger quantities than all the fish caught at the present time. The second way is to use the biological resources of the open ocean. The biological productivity of the Ocean is especially great in the area of upwelling of deep waters. One of these upwellings, located off the coast of Peru, provides 15% of the world's fish production, although its area is no more than two hundredths of a percent of the entire surface of the World Ocean. Finally, the third way is the cultural breeding of living organisms, mainly in coastal zones. All these three methods have been successfully tested in many countries of the world, but locally, therefore, the fish catch, which is detrimental in terms of volume, continues. At the end of the 20th century, the Norwegian, Bering, Okhotsk, and Sea of Japan were considered the most productive water areas.

The ocean, being a pantry of the most diverse resources, is also a free and convenient road that connects distant continents and islands. Maritime transport provides almost 80% of transportation between countries, serving the growing global production and exchange. The oceans can serve as a waste recycler. Due to the chemical and physical effects of its waters and the biological influence of living organisms, it disperses and purifies the bulk of the waste entering it, maintaining the relative balance of the Earth's ecosystems. For 3000 years, as a result of the water cycle in nature, all the water in the oceans is renewed.

Pollution of the oceans.

Oil and oil products

a). Paraffins (alkenes). (up to 90% of the total composition) - stable substances, the molecules of which are expressed by a straight and branched chain of carbon atoms. Light paraffins have maximum volatility and solubility in water.

b). Cycloparaffins. (30 - 60% of the total composition) saturated cyclic compounds with 5-6 carbon atoms in the ring. In addition to cyclopentane and cyclohexane, bicyclic and polycyclic compounds of this group are found in oil. These compounds are very stable and difficult to biodegrade.

c). Aromatic hydrocarbons. (20 - 40% of the total composition) - unsaturated cyclic compounds of the benzene series, containing 6 carbon atoms in the ring less than cycloparaffins. Oil contains volatile compounds with a molecule in the form of a single ring (benzene, toluene, xylene), then bicyclic (naphthalene), polycyclic (pyrone).

G). Olefins (alkenes). (up to 10% of the total composition) - unsaturated non-cyclic compounds with one or two hydrogen atoms at each carbon atom in a molecule that has a straight or branched chain.

Oil and oil products are the most common pollutants in the oceans. By the beginning of the 1980s, about 16 million tons of oil were annually entering the ocean, which accounted for 0.23% of world production. The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes. In the period 1962-79, about 2 million tons of oil entered the marine environment as a result of accidents. Over the past 30 years, since 1964, about 2,000 wells have been drilled in the World Ocean, of which 1,000 and 350 industrial wells have been equipped in the North Sea alone. Due to minor leaks, 0.1 million tons of oil are lost annually. Large masses of oil enter the seas along rivers, with domestic and storm drains. The volume of pollution from this source is 2.0 million tons / year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses.

The oil film changes the composition of the spectrum and the intensity of light penetration into the water. The light transmission of thin films of crude oil is 11-10% (280nm), 60-70% (400nm). A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct oil in water and reverse water in oil. Direct emulsions, composed of oil droplets with a diameter of up to 0.5 μm, are less stable and are typical for oils containing surfactants. When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.

Pesticides

Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups:

Insecticides to control harmful insects,

Fungicides and bactericides - to combat bacterial plant diseases,

Herbicides against weeds.

It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control. Currently, more than 5 million tons of pesticides enter the world market. About 1.5 million tons of these substances have already entered the terrestrial and marine ecosystems by ash and water. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater. In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others. Synthesized insecticides are divided into three main groups: organochlorine, organophosphorus and carbonates.

Organochlorine insecticides are obtained by chlorination of aromatic and heterocyclic liquid hydrocarbons. These include DDT and its derivatives, in the molecules of which the stability of aliphatic and aromatic groups in the joint presence increases, various chlorinated derivatives of chlorodiene (eldrin). These substances have a half-life of up to several decades and are very resistant to biodegradation. In the aquatic environment, polychlorinated biphenyls are often found - derivatives of DDT without an aliphatic part, numbering 210 homologues and isomers. Over the past 40 years, more than 1.2 million tons of polychlorinated biphenyls have been used in the production of plastics, dyes, transformers, and capacitors. Polychlorinated biphenyls (PCBs) enter the environment as a result of industrial wastewater discharges and the incineration of solid waste in landfills. The latter source delivers PBCs to the atmosphere, from where they fall out with atmospheric precipitation in all regions of the globe. Thus, in snow samples taken in Antarctica, the content of PBC was 0.03 - 1.2 kg. / l.

Synthetic surfactants

Detergents (surfactants) belong to an extensive group of substances that lower the surface tension of water. They are part of synthetic detergents (SMC), widely used in everyday life and industry. Together with wastewater, surfactants enter the mainland waters and the marine environment. SMS contain sodium polyphosphates, in which detergents are dissolved, as well as a number of additional ingredients that are toxic to aquatic organisms: flavoring agents, bleaching agents (persulphates, perborates), soda ash, carboxymethylcellulose, sodium silicates. Depending on the nature and structure of the hydrophilic part of the surfactant molecules, they are divided into anionic, cationic, amphoteric, and nonionic. The latter do not form ions in water. The most common among the surfactants are anionic substances. They account for more than 50% of all surfactants produced in the world. The presence of surfactants in industrial wastewater is associated with their use in such processes as flotation beneficiation of ores, separation of chemical technology products, production of polymers, improvement of conditions for drilling oil and gas wells, and equipment corrosion control. In agriculture, surfactants are used as part of pesticides.

Compounds with carcinogenic properties

Carcinogenic substances are chemically homogeneous compounds that exhibit transforming activity and the ability to cause carcinogenic, teratogenic (violation of embryonic development processes) or mutagenic changes in organisms. Depending on the conditions of exposure, they can lead to growth inhibition, accelerated aging, disruption of individual development, and changes in the gene pool of organisms. Substances with carcinogenic properties include chlorinated aliphatic hydrocarbons, vinyl chloride, and especially polycyclic aromatic hydrocarbons (PAHs). The maximum amount of PAHs in present-day sediments of the World Ocean (more than 100 µg/km of dry matter mass) was found in tectonically active zones subject to deep thermal impact. The main anthropogenic sources of PAHs in the environment are the pyrolysis of organic substances during the combustion of various materials, wood, and fuel.

Heavy metals

Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are among the common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere. Mercury, lead and cadmium are the most dangerous for marine biocenoses. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 121 thousand. tons of mercury, and a significant part is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons / year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. At the same time, some bacteria convert chlorides into highly toxic methyl mercury. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. By 1977, there were 2,800 victims of Minomata disease, which was caused by waste products from factories for the production of vinyl chloride and acetaldehyde, which used mercury chloride as a catalyst. Insufficiently treated wastewater from enterprises entered the Minamata Bay. Pigs are a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, pigs are actively dispersed into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines. The migration flow of lead from the continent to the ocean goes not only with river runoff, but also through the atmosphere.

With continental dust, the ocean receives (20-30) * 10 ^ 3 tons of lead per year.

Dumping of waste into the sea for the purpose of disposal

Many countries with access to the sea carry out marine disposal of various materials and substances, in particular soil excavated during dredging, drill slag, industrial waste, construction waste, solid waste, explosives and chemicals, and radioactive waste. The volume of burials amounted to about 10% of the total mass of pollutants entering the World Ocean. The basis for dumping in the sea is the ability of the marine environment to process a large amount of organic and inorganic substances without much damage to the water. However, this ability is not unlimited. Therefore, dumping is considered as a forced measure, a temporary tribute to the imperfection of technology by society. Industrial slags contain a variety of organic substances and heavy metal compounds. Household waste contains on average (by weight of dry matter) 32-40% of organic matter; 0.56% nitrogen; 0.44% phosphorus; 0.155% zinc; 0.085% lead; 0.001% mercury; 0.001% cadmium. During the discharge, the passage of the material through the water column, part of the pollutants goes into solution, changing the quality of the water, the other is sorbed by suspended particles and goes into bottom sediments. At the same time, the turbidity of the water increases. The presence of organic substances purely leads to the rapid consumption of oxygen in water and not caustically to its complete disappearance, the dissolution of suspensions, the accumulation of metals in dissolved form, and the appearance of hydrogen sulfide. The presence of a large amount of organic matter creates a stable reducing environment in the soil, in which a special type of interstitial water appears, containing hydrogen sulfide, ammonia, and metal ions. Benthic organisms and others are affected to varying degrees by the discharged materials. In the case of the formation of surface films containing petroleum hydrocarbons and surfactants, gas exchange at the air-water interface is disrupted. Pollutants entering the solution can accumulate in the tissues and organs of hydrobionts and have a toxic effect on them. The dumping of dumping materials to the bottom and prolonged increased turbidity of the given water leads to the death of inactive forms of benthos from suffocation. In surviving fish, mollusks and crustaceans, the growth rate is reduced due to the deterioration of feeding and breathing conditions. The species composition of a given community often changes. When organizing a system for controlling waste emissions into the sea, the determination of dumping areas, the determination of the dynamics of pollution of sea water and bottom sediments is of decisive importance. To identify possible volumes of discharge into the sea, it is necessary to carry out calculations of all pollutants in the composition of the material discharge.

thermal pollution

Protection of the seas and oceans

The most serious problem of the seas and oceans in our century is oil pollution, the consequences of which are detrimental to all life on Earth. Therefore, in 1954, an international conference was held in London to work out concerted action to protect the marine environment from oil pollution. It adopted a convention defining the obligations of states in this area. Later, in 1958, four more documents were adopted in Geneva: on the high seas, on the territorial sea and the contiguous zone, on the continental shelf, on fishing and the protection of living resources of the sea. These conventions have legally fixed the principles and norms of maritime law. They obligated each country to develop and enforce laws prohibiting the pollution of the marine environment with oil, radio waste and other harmful substances. A conference held in London in 1973 adopted documents on the prevention of pollution from ships. According to the adopted convention, each ship must have a certificate - evidence that the hull, mechanisms and other equipment are in good condition and do not cause damage to the sea. Compliance with certificates is checked by the inspection when entering the port.

Drainage of oily waters from tankers is prohibited; all discharges from them must be pumped out only to onshore reception points. Electrochemical installations have been created for the treatment and disinfection of ship wastewater, including household wastewater. The Institute of Oceanology of the Russian Academy of Sciences has developed an emulsion method for cleaning sea tankers, which completely excludes the ingress of oil into the water area. It consists in adding several surfactants (ML preparation) to the wash water, which allows cleaning on the ship itself without discharging contaminated water or oil residues, which can be subsequently regenerated for further use. It is possible to wash up to 300 tons of oil from each tanker. In order to prevent oil leaks, the designs of oil tankers are being improved. Many modern tankers have a double bottom. If one of them is damaged, the oil will not spill out, it will be delayed by the second shell.

Ship captains are obliged to record in special logs information about all cargo operations with oil and oil products, note the place and time of delivery or discharge of contaminated sewage from the ship. For the systematic cleaning of water areas from accidental spills, floating oil skimmers and side barriers are used. Physical and chemical methods are also used to prevent oil from spreading. A preparation of a foam group has been created, which, when in contact with an oil slick, completely envelops it. After pressing, the foam can be reused as a sorbent. Such drugs are very convenient due to ease of use and low cost, but their mass production has not yet been established. There are also sorbent agents based on vegetable, mineral and synthetic substances. Some of them can collect up to 90% of spilled oil. The main requirement for them is unsinkability. After collecting oil by sorbents or mechanical means, a thin film always remains on the surface of the water, which can be removed by spraying chemicals that decompose it. But at the same time, these substances must be biologically safe.

In Japan, a unique technology has been created and tested, with the help of which it is possible to eliminate a giant spot in a short time. Kansai Sagge Corporation has released ASWW reagent, the main component of which is specially treated rice hulls. Sprayed on the surface, the drug absorbs the ejection within half an hour and turns into a thick mass that can be pulled off with a simple net. The original cleaning method was demonstrated by American scientists in the Atlantic Ocean. A ceramic plate is lowered under the oil film to a certain depth. An acoustic record is connected to it. Under the action of vibration, it first accumulates in a thick layer above the place where the plate is installed, and then mixes with water and begins to gush. An electric current applied to the plate sets fire to the fountain, and the oil burns completely.

To remove oil stains from the surface of coastal waters, American scientists have created a modification of polypropylene that attracts fat particles. On a catamaran boat, a kind of curtain made of this material was placed between the hulls, the ends of which hang down into the water. As soon as the boat hits the slick, the oil sticks firmly to the "curtain". All that remains is to pass the polymer through the rollers of a special device that squeezes the oil into a prepared container. Since 1993, the dumping of liquid radioactive waste (LRW) has been banned, but their number is steadily growing. Therefore, in order to protect the environment, in the 1990s, projects for the treatment of LRW began to be developed. In 1996, representatives of Japanese, American and Russian firms signed a contract for the creation of a plant for the processing of liquid radioactive waste accumulated in the Russian Far East. The government of Japan allocated 25.2 million dollars for the implementation of the project. However, despite some success in finding effective means to eliminate pollution, it is too early to talk about solving the problem. It is impossible to ensure the cleanliness of the seas and oceans only by introducing new methods of cleaning water areas. The central task that all countries need to solve together is the prevention of pollution.

Conclusion

The consequences, to which the wasteful, careless attitude of mankind towards the Ocean leads, are terrifying. The destruction of plankton, fish and other inhabitants of ocean waters is far from all. The damage could be much greater. Indeed, the World Ocean has general planetary functions: it is a powerful regulator of the moisture circulation and thermal regime of the Earth, as well as the circulation of its atmosphere. Pollution can cause very significant changes in all these characteristics, which are vital for the climate and weather regime on the entire planet. Symptoms of such changes are already observed today. Severe droughts and floods are repeated, destructive hurricanes appear, severe frosts come even to the tropics, where they never happened. Of course, it is not yet possible to even approximately estimate the dependence of such damage on the degree of pollution. Oceans, however, the relationship undoubtedly exists. Be that as it may, the protection of the ocean is one of the global problems of mankind. The Dead Ocean is a dead planet, and therefore all of humanity.

Bibliography

1. "World Ocean", V.N. Stepanov, "Knowledge", M. 1994

2. Textbook on geography. Yu.N.Gladky, S.B.Lavrov.

3. "Ecology of the environment and man", Yu.V. Novikov. 1998

4. "Ra" Thor Heyerdahl, "Thought", 1972

5. Stepanovskikh, "Environmental Protection".

Portal for the student. Self-training