Processes that reduce the quality of surface waters. Results of monitoring the water quality of surface water bodies. Objects and methods of research

Surface water on land is water that flows (streams) or collects on the surface of the earth (reservoirs). There are sea, lake, river, swamp and other waters. Surface water resides permanently or temporarily in surface water bodies. Objects of surface water are: seas, lakes, rivers, swamps and other watercourses and reservoirs. There are salty and fresh waters of land.

The formation of surface water is a complex process. Streams falling from the sky in the form of rain or snow are water evaporated from the seas and oceans. The nature of the terrain through which it flows under the influence of gravity (at the same time, water is the strongest destroyer of that part of the earth’s crust located above sea level) determines the route along which it, collecting in streams and rivers, rushes back to the sea. Thus, one major phase of the hydrological cycle is completed.

Flowing over the surface, water captures and carries insoluble mineral particles of sand and soil, some of them it leaves along the road, some it carries to the sea, and some substances dissolve in it.

Surface water, passing through uneven terrain and falling from rocks, is saturated with oxygen from the air; its compounds with organic and inorganic substances washed from the land of a particular area and sunlight support a wide variety of life forms in the form of algae, fungi, bacteria, small crustaceans and fish.

In addition, the beds of many rivers are covered with trees, in the areas through which they flow, if the river banks are covered with forests. Fallen leaves and needles of trees fall into rivers; they play a big role in filling the water with biological content. Once in water they dissolve in it. It is this material that subsequently becomes the main cause of contamination of ion exchange resins that are used for water purification.

The physical and chemical properties of surface water contaminants change gradually over time. Sudden natural disasters can lead to dramatic changes in the composition of surface water sources in a short period of time. The chemistry of surface water also changes depending on the season, for example, during periods of heavy rain and snowmelt (a period of major flooding when river levels rise sharply). This can have a beneficial or unfavorable effect on water characteristics, depending on the geochemistry and biology of the area.

Surface water chemistry also changes throughout the year through several cycles of drought and rain. Long periods of drought seriously affect the shortage of water for industrial use. In places where rivers flow into seas, it is possible for salt water to enter the river during periods of drought, creating additional problems. Industrial users should focus on the variability of surface waters, which must be taken into account when designing treatment facilities and developing other programs.

The quality of surface water depends on a combination of climatic and geological factors. The main climatic factor is the amount and frequency of precipitation, as well as the environmental situation in the region. Precipitation carries with it a certain amount of undissolved particles, such as dust, volcanic ash, pollen, bacteria, fungal spores, and sometimes larger microorganisms. The ocean is a source of various salts dissolved in rainwater. Chloride, sulfate, sodium, magnesium, calcium and potassium ions can be found in it. Industrial emissions into the atmosphere also “enrich” the chemical palette, mainly due to organic solvents and oxides of nitrogen and sulfur, which cause “acid rain”. Chemicals used in agriculture also contribute. Geological factors include the structure of river beds. If the channel is formed by limestone rocks, then the water in the river is usually clear and hard. If the channel is made of impermeable rocks, such as granite, then the water will be soft, but cloudy due to a large number of suspended particles of organic and inorganic origin. In general, surface waters are characterized by relative softness, high organic content and the presence of microorganisms.

Surface waters include streams, ponds, swamps and glaciers. In natural (rivers, streams) and artificial (canals) watercourses, water moves along the channel in the direction of the general slope of the surface. Watercourses can be permanent or temporary (drying up or freezing).

A reservoir is an accumulation of water in a natural (lake) or artificial (reservoir, pond) depression, the flow from which is absent or slow. Only a small part of the hydrosphere is contained in rivers, about four times less than in swamps, and sixty times less than in lakes.

The importance of rivers in the water cycle is immeasurably greater than the water they contain, since the water in rivers is renewed on average every 19 days.

For comparison, in swamps complete renewal of water occurs in 5 years, in lakes – in 17 years.

Thanks to the flow of water, the rivers are better saturated with oxygen and the quality of the water here is better. It was along the banks of the rivers that the first human settlements arose.

For a long time, rivers served as the main transport arteries and defensive lines, and were sources of water and fish. A river is usually called a natural, constant stream of water flowing in a depression (bed) developed by it. River valleys are elongated depressions on the earth's surface, carved out by constant water flows. All river valleys have slopes and a flat bottom. The water flow constantly carries many erosion products, which are deposited in the bottom of the valley or carried out to the sea. River sediments are called alluvium. Especially a lot of alluvium accumulates in the bottoms of valleys in the lower reaches of rivers, where the surface slopes are the least. When the snow melts, part of the bottom (floodplain) is filled with hollow water. A river stream always tends to deepen its channel to a certain level. This level is called the erosion base. For a river, the basis for erosion is the level of the sea, lake or other river into which the river flows. The river constantly deepens its channel and a time comes when during high water the river can no longer flood its floodplain. The river begins to develop a new floodplain at a lower level, and the old floodplain turns into a terrace - a high step in the bottom of the river valley. The older and larger the river, the more terraces can be counted in its valley.

In reality, a river is a complex natural formation (system) consisting of many elements. The area from which a river system collects its waters is called a river basin. There is a border - a watershed - between neighboring river basins.

The Amazon River has the largest basin; it is also the most abundant river (average annual flow is 220,000 cubic meters per second).

The density of the river network depends on many factors: first of all, on the general moisture content of the territory - the greater it is, the greater the density of rivers, such as in the tundra and forest zones; from the relief and geological structure of the territory - in areas of distribution of soluble and fractured (karst) limestones, the river network is sparse, and the rivers, as a rule, are shallow and drying up.

All rivers have a beginning and an end. The beginning of the river, the place where a permanent watercourse appears, is called the source. The source may be a lake, swamp, spring or glacier.

Mouth - the place where a river flows into the sea, lake or one river into another. A number of large northern rivers have mouths that look like narrow funnel-shaped bays - they are called estuaries. In estuaries, river sediments are carried out to the sea by waves and currents. Large estuaries include rivers such as the Congo in Africa, the Thames and Seine in Europe, and the Russian Yenisei and Ob rivers. In contrast, in deltas, on the contrary, rivers literally wander, flowing into the sea, among their own sediments, breaking up into numerous branches and channels. The largest deltas have rivers - the Amazon, Yellow River, Lena, Mississippi, etc.

The terrain directly affects the slope of the river bed and, accordingly, the speed of water flow. The difference in elevations of the water surface in a river at two points located at some distance along its course is called the fall of the river. The slope of a river is the ratio of the fall of a river to its length. The fall of water from a steep ledge is called a waterfall.

The highest waterfall on Earth is Angel (1054 m) in the Orinoco River basin. The widest (1800 m) is Victoria on the river. Zambezi (its height is 120 m). Lowland rivers usually flow calmly and smoothly, with a slight fall and small slopes. Large rivers have wide valleys and are convenient for navigation. Mountain rivers have large slopes and, therefore, rapid currents and narrow, rapids, deep valleys. The water in the riverbed rushes at breakneck speed, foams, and forms whirlpools and waterfalls.

Mountain rivers are usually unsuitable for navigation, but they have large reserves of hydroelectric power and are convenient for the construction of hydroelectric power stations.

For the national economy (navigation, construction of hydroelectric power stations, water supply to populated areas, irrigation of fields), very important characteristics of rivers are water flow (the amount of water passing along the channel per unit of time) and annual flow (water flow in the river per year).

The amount of annual runoff characterizes the water content of the river and depends on climate (the ratio of precipitation and evaporation over the area of ​​the river basin) and topography (flat terrain reduces runoff, mountainous, on the contrary, increases it).

The amount of material transported by water, consisting of chemical and biological substances dissolved in water and small solid particles - the amount of solid runoff - depends on the speed and resistance to erosion of rocks. Climatic conditions affect the nutrition and regime of rivers (glacial, snow, rain and ground). The intra-annual distribution of flow - the river regime - depends on the prevailing type of nutrition. River regime is the life of a river flow for some time (days, seasons and years). According to their regime, rivers are divided into several main groups. On rivers with spring floods and predominantly snow-fed. Relatively rapid melting of the snow cover leads to rising and overflowing water (spring flood). In summer, the rivers switch to rain-fed water and, although a large amount of precipitation falls, due to increased evaporation, these rivers become shallow. Rivers experience low water - a time of stable low water level in the riverbed. In winter, during freeze-up (freezing and formation of stationary ice), rivers are fed exclusively by groundwater and winter low water is observed. The flood regime is typical for rivers with rain and mixed feeding. Floods - short-term (sometimes very significant) rises of water in the river - unlike floods, can occur at any time of the year and are most often associated with heavy rains. In warm winters, floods may occur at this time of year.

Late melting of snow and glaciers in the mountains causes summer floods. This regime is characteristic, for example, of rivers originating in the Alpine mountains. Rivers with a monsoon climate are characterized by flood conditions in the second half of summer and low water in winter. Due to the thin snow cover, spring floods are weak or completely absent. Monsoons often bring heavy rainfall of a torrential nature, which leads to catastrophic floods. At this time, vast territories with numerous villages are under water. Buildings are destroyed, crops, animals and even people are killed. The rivers of East and South Asia are especially violent: the Amur, Yellow River, Yangtze, Ganges.

Lakes differ not only in size and depth, but also in the color and properties of the water, the composition and number of organisms inhabiting them. The number of lakes (lake content of the territory) is influenced by the increased humidity of the climate and the topography with numerous closed basins. The size, depth, and shape of lakes largely depend on the origin of their basins. There are basins of tectonic, glacial, karst, thermokarst, stanitsa and volcanic origin. There are also dammed (dammed or dammed) lakes, which are formed as a result of blocking the river bed with blocks of rock during landslides in the mountains.

Tectonic lake basins are large in size and depth, as they were formed at the site of subsidence, cracks and faults in the earth's crust. Classic tectonic lakes are the largest lakes in the world: the Caspian and Baikal in Eurasia, the Great African and North American lakes.

Glacial lake basins are formed during the plowing activity of glaciers or as a result of erosion or accumulation of glacial waters in areas of accumulation of glacial material and the formation of glacial landforms. There are many such lakes in Finland, northern Poland, Karelia, etc.

Karst lake basins are formed as a result of failures, subsidence and erosion, primarily of easily soluble rocks: limestone, dolomite, gypsum, salts. There are many thermokarst lakes in the permafrost zone in the tundra and forest-tundra. Here water dissolves underground ice.

Ancient lakes are the remains of abandoned river beds.

Volcanic lake basins arose in volcanic craters or in depressions of lava fields. These are the Kronotskoye and Kuril lakes, lakes in New Zealand. Based on the salinity of the water, lakes are divided into fresh and salty. Unlike rivers, the regime of lakes depends on whether the rivers flowing from it are a flowing lake (Baikal) or a closed reservoir (Caspian).

Swamps are areas of land with abundant, stagnant or weakly flowing soil moisture for most of the year, with characteristic (marsh) vegetation, lack of oxygen and constant formation of peat (the peat layer should reach at least 0.3 m, if there is less peat, this will wetlands. Peat is the name given to semi-decomposed plant remains. Swamps cannot be called reservoirs, since they contain water in a bound state. But swamps contain only 5-10% of dry matter (peat), the rest is water. Therefore, swamps are important accumulators of fresh water. Waterlogging is facilitated by the presence of a nearby aquitard and they are most common in areas with permafrost. The most common swamps are in the forests of the Northern Hemisphere, as well as in Brazil and India. Due to the abundance of swamps and swampy forests, the forest zone in Western Siberia is called forest swamp. The largest swamp in the world is the Vasyugan swamp.The processes of waterlogging in this region continue to this day. The average horizontal speed of spread of the edges of the swamps and their encroachment on the surrounding forests is 10-15 cm per year.

The methods for forming swamps are different. This includes overgrowing, peat formation of reservoirs (lakes) and stagnation of water in places where springs emerge and where groundwater is close to the ground; as well as the accumulation of moisture in depressions and flat areas under forests and meadows (forest clearings are especially often swamped.) Based on their food sources, upland swamps (fed by atmospheric waters), lowland swamps (ground moisture) and transitional swamps are distinguished. When classified according to the degree of richness of the substrate, they correspond to oligotrophic (poor), eutrophic (rich) and mesotrophic. Lowland swamps are formed mainly in the lowest areas of the relief (in floodplains, ancient lake basins).

Groundwater is highly mineralized and, entering the swamp, it enriches it. Therefore, in low-lying swamps, sedges, horsetails, reeds, mosses grow in a dense continuous cover, and thickets of black alder are often found. Many birds usually find refuge here, and their droppings, containing nitrogenous substances, also enrich the swamp.

Peat from lowland bogs is an excellent fertilizer.

Raised bogs most often form in watershed areas, they are moistened by atmospheric waters, which are very poor in nutrients, and the vegetation here is completely different. These are mainly mosses and stunted trees. Raised bog peat with poor vegetation contains little ash, so it is a combustible mineral and is used as fuel.

Swamps are of great water conservation importance. By accumulating huge reserves of water, they regulate the water regime of rivers and maintain the stability of the water balance of the territory; purify the water passing through them. Swamps are the sources of many rivers. The vegetation of the swamps is not of particular nutritional value. But after draining, they are used for agricultural or forestry crops. However, at the same time, small rivers often become shallow and disappear.

Surface water pollution

The water quality of most water bodies does not meet regulatory requirements. Long-term observations of the dynamics of surface water quality reveal a tendency to increase the number of sites with high levels of pollution and the number of cases of extremely high content of pollutants in water bodies. The condition of water sources and centralized water supply systems cannot guarantee the required quality of drinking water, and in a number of regions (Southern Urals, Kuzbass, some territories of the North) this condition has reached a dangerous level for human health. Sanitary and epidemiological surveillance services constantly note high pollution of surface waters. About 1/3 of the total mass of pollutants is introduced into water sources with surface and storm runoff from areas of sanitary undeveloped areas, agricultural facilities and lands, which affects the seasonal, during the spring flood, deterioration in the quality of drinking water, which is observed annually in large cities, including including in Novosibirsk. In this regard, water is hyperchlorinated, which, however, is unsafe for public health due to the formation of organochlorine compounds.

One of the main pollutants of surface waters is oil and petroleum products. Oil can enter water as a result of natural seeps in areas where it occurs.

But the main sources of pollution are associated with human activity: oil production, transportation, refining and use of oil as fuel and industrial raw materials.

Among industrial products, toxic synthetic substances occupy a special place in their negative impact on the aquatic environment and living organisms.

They are increasingly used in industry, transport, and household services. The concentration of these compounds in wastewater is usually 5-15 mg/l with a MPC of -0.1 mg/l. These substances can form a layer of foam in reservoirs, which is especially noticeable on rapids, riffles, and sluices.

The ability to foam in these substances appears already at a concentration of 1-2 mg/l. The most common pollutants in surface waters are phenols, easily oxidized organic substances, copper and zinc compounds, and in some regions of the country - ammonium and nitrite nitrogen, lignin, xanthates, aniline, methyl mercaptan, formaldehyde, etc. A huge amount of pollutants is introduced into surface waters with wastewater from ferrous and non-ferrous metallurgy, chemical and petrochemical enterprises.

Oil, gas, coal, forestry, pulp and paper industries, agricultural and municipal enterprises, surface runoff from adjacent areas. Mercury, lead and their compounds pose a slight danger to the aquatic environment from metals. Expanded production (without treatment facilities) and the use of pesticides in fields lead to severe pollution of water bodies with harmful compounds.

Pollution of the aquatic environment occurs as a result of the direct introduction of pesticides during the treatment of reservoirs for pest control, the entry into reservoirs of water flowing from the surface of treated agricultural land, during the discharge of waste from manufacturing enterprises into reservoirs, as well as as a result of losses during transportation, storage and partly from atmospheric precipitation. Along with pesticides, agricultural runoff contains a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields.

In addition, large amounts of organic nitrogen and phosphorus compounds come from livestock farms and sewage. An increase in the concentration of nutrients in the soil leads to a disruption of the biological balance in the reservoir. Initially, the number of microscopic algae in such a reservoir sharply increases. As the food supply increases, the number of crustaceans, fish and other aquatic organisms increases. Then a huge number of organisms die off. It leads to the consumption of all oxygen reserves contained in the water and the accumulation of hydrogen sulfide. The situation in the reservoir changes so much that it becomes unsuitable for the existence of any form of organisms. The reservoir is gradually “dying.”

The current level of wastewater treatment is such that even in waters that have undergone biological treatment, the content of nitrates and phosphates is sufficient for intensive eutrophication of water bodies.

Eutrophication is the enrichment of a reservoir with nutrients, stimulating the growth of phytoplankton. This causes the water to become cloudy, benthic plants die, the concentration of dissolved oxygen decreases, and fish and shellfish living in the depths suffocate.

Disinfection and disinfection of surface waters

Another important block of any installation is the water disinfection and disinfection block. Disinfection usually means cleaning surface water from all types of living microorganisms, including not only organisms potentially dangerous to human health such as bacteria and viruses, but also microalgae that can harm equipment, pipelines and other objects that come into contact with contaminated water. And in order, for example, to avoid the entry of similar harmful substances into the soil, they use autonomous suburban sewage systems, information about which can certainly be very useful. Today, there are several methods of wastewater treatment, each of which has both its advantages and disadvantages; we will dwell on some of them in more detail.

One of the most common methods of purifying surface water from potentially dangerous microorganisms is their oxidation using certain reagents. The cheapest method is water chlorination, since this reagent is considered the cheapest. A more expensive, but more reliable and safe reagent is ozone, which, after purification, simply decomposes into harmless compounds such as air, water or carbon dioxide, unlike chlorine, which remains in water and can cause harm to both the human body and household or industrial water. technology.

Another method of purifying surface water from microorganisms is water irradiation with ultraviolet light, which is considered one of the most effective and safe methods of water disinfection. When water is irradiated, ultraviolet light penetrates the nucleus of living cells, causing irreversible damage to the DNA of the latter, which causes the microorganism to lose its ability to reproduce. Purification using ultraviolet irradiation is today considered one of the most environmentally friendly technologies for water disinfection, which guarantees high quality and good results.

The work reflects the main results of assessing the water quality of the Upper Volga reservoir for the period 2011–2014. An analysis of the hydrochemical data of the reservoir waters was carried out. Priority pollutants have been identified, which include manganese, total iron, color, ammonium ion, and petroleum products. The results of calculation of integral indicators of water quality are presented: indices WPI (Water Pollution Index), WCI (General Sanitary Index of Water Quality) and UKIPV (Specific Combinatorial Index of Water Pollution). An assessment of the water quality of the Upper Volga Reservoir was carried out. In general, the water quality of the Upper Volga reservoir according to the value of integral hydrochemical indices is assessed as “dirty” water (according to the value of the WPI index), moderately polluted water (according to the value of the WCI index), and very polluted water (according to the value of the UKIW index).

water quality

Verkhnevolzhskoe reservoir

integral quality indices

1. Upper Volga Reservoir // Great Soviet Encyclopedia. – M.: Soviet Encyclopedia, 1969–1978. URL: www./enc-dic.com/enc_sovet/Verhnevolzhskoe_ vodohranilische-3512.html (access date: 07/17/15).

2. Hydrochemical indicators of the state of the environment: reference materials / ed. T.V. Guseva. – M.: Forum: INFRA-M, 2007. – 192 p.

3. Lazareva G.A., Klenova A.V. Assessment of the ecological state of the Upper Volga reservoir based on hydrochemical indicators // Collection of proceedings of the VII international scientific conference of young scientists and talented students “Water resources, ecology and hydrological safety” (Moscow, IVP RAS, Russian Academy of Natural Sciences, December 11–13, 2013) . – M., 2014. – P.173-176.

4. RD 52.24.643-2002 Method for a comprehensive assessment of the degree of pollution of surface waters based on hydrochemical indicators - Roshydromet, 2002. - 21 p.

5. Shitikov V.K., Rosenberg G.S., Zinchenko T.D. Quantitative hydroecology: methods of system identification. – Togliatti: IEVB RAS, 2003. – 463 p.

The quality of water in water bodies is formed under the influence of both natural and anthropogenic factors. As a result of human activity, many pollutants of varying degrees of toxicity can enter water bodies. Water bodies are polluted by runoff from agricultural and industrial enterprises and wastewater from populated areas. In modern conditions, the problem of providing the population with clean water is becoming increasingly urgent, and studying the condition of water bodies is one of the most important tasks.

The purpose of this work is an assessment of the water quality of the Upper Volga Reservoir using integral quality indicators.

Objects and methods of research

The Upper Volga Reservoir was created in 1843 (reconstructed in 1944-47) and consists of interconnected lakes Sterzh, Vselug, Peno and Volgo. The reservoir is located in the north-west of the Tver region on the territory of the Ostashkovsky, Selizharovsky and Penovsky districts. The surface area of ​​the reservoir is 183 km2, volume - 0.52 km3, length - 85 km, maximum width 6 km. The length of the coastline is 225 km. At a high water level, close to the normal backwater level (206.5 m), the reservoir is a single reservoir, and during low water, with strong drawdown, it is divided into lakes that are poorly connected to each other. The water resources of the Upper Volga Reservoir are used during the summer low-water period to regulate levels in the upper reaches of the Volga, as well as for industrial purposes, municipal needs, agriculture and livestock breeding. The reservoir is of great importance for recreation, tourism and fishing.

During the research, 3 sections of the Upper Volga Reservoir were studied (section of Lake Volgo, Peno village; section of Lake Volgo, Devichye village; section of the Verkhnevolzhsky Beishlot) (Fig. 1) according to hydrochemical indicators for the period from 2011 to 2014.

Figure 1. Map of sampling stations of the Upper Volga Reservoir: 1 - section of the lake. Volgo, Peno village, 2 - lake section. Volgo, village Devichye, 3 - Verkhnevolzhsky beishlot

The work used data provided by the Dubna Ecoanalytical Laboratory (DEAL) of the Federal State Institution "Tsentrregionvodkhoz" for such hydrochemical indicators as: hydrogen index, color, ammonium ion, nitrate ion, nitrite ion, phosphate ion, total iron, chloride ion , sulfate ion, manganese, magnesium, biochemical oxygen demand, copper, zinc, lead, petroleum products, dissolved oxygen, nickel.

Research results

Analysis of hydrochemical data showed that all studied sections of the Upper Volga reservoir are characterized by high contents of manganese, total iron and ammonium ions in the water, the concentrations of which always exceeded the MAC; in certain periods, excesses of the MAC for petroleum products were noted. The concentrations of these substances changed slightly over the study period.

To assess the water quality of the Upper Volga reservoir for 2011-2014. integral indicators of water quality were calculated: indices WPI (Water Pollution Index), WQI (General Sanitary Index of Water Quality) and UKIW (Specific Combinatorial Index of Water Pollution). The results obtained are presented in Table 1.

Table 1

The value of the indices WPI, IKV, UKIVZ, water quality class, qualitative and ecological state of water in the sections of the Upper Volga Reservoir

Continuation of Table 1

The hydrochemical water pollution index (WPI) was used as the main comprehensive indicator of water quality until 2002. Classification of water quality according to WPI values ​​makes it possible to divide surface waters into 7 classes depending on the degree of their pollution. The calculation of WPI is carried out using six ingredients: the mandatory ones are dissolved oxygen and BOD5, and 4 substances that had the highest relative concentrations (Ci/MPCi). The main disadvantage of this method of assessing water quality is that a small range of pollutants is taken into account.

The maximum values ​​of the WPI index at all sections are observed in the winter-spring period, and the minimum - in the autumn. According to the value of the WPI index in 2011-2013, in all sections the water quality is assessed as “dirty” (water quality class - 5). In 2014, at the Verkhnevolzhsky Beishlot site (No. 3) there was a deterioration in water quality to quality class 6 - “very dirty”, while at the lake site. Volgo village Peno (No. 1) and lake. Volgo village Devichye (No. 2) water quality has not changed (Fig. 2).

Figure 2. Changes in WPI index values ​​at reservoir sites for 2011-2014.

To determine the general sanitary water quality index (WQI), a point assessment is carried out (from 1 to 5 points). Points are assigned to each indicator used for calculation, the weight of the indicator is also taken into account, after which the value of the ICI is determined.

In general, according to the values ​​of the WCI index during the period under review (2011-2014), in all sections of the water throughout almost the entire study period, with a few exceptions, they are characterized as “moderately polluted” (water quality class 3) (Fig. 3).

Figure 3. Changes in the values ​​of the WCI index at the reservoir sites for 2011-2014.

The specific combinatorial index of water pollution (SCIPI) today is becoming a priority when assessing water quality. Classification of water quality according to SCWI values ​​makes it possible to divide surface waters into 5 classes depending on the degree of their pollution. Unlike WPI, with this approach to calculation, not only the multiple of exceeding the MPC is determined, but also the repeatability of cases of exceeding standard values ​​is determined. The data for calculating the UKIW index make it possible to more accurately reflect the quality of surface waters.

According to the value of the UKIZV index, the water of the Upper Volga Reservoir during the observed period (2011-2014) in all sections is assessed as “very polluted” (class 3, category “B”), with the exception of the section in the lake section. Volgo village Peno in 2014, where the degree of water pollution is characterized as “polluted” (class 3, category “A”) (Fig. 4).

Figure 4. Changes in the values ​​of the UKIZV index at the reservoir sites for 2011-2014.

An increase in the values ​​of the UKIVZ index was noted at sites located downstream of the reservoir, and although they do not go beyond the values ​​of one quality class and category, this indicates a slight deterioration in water quality. At the sites in the area of ​​the village of Devechye and the Verkhnevolzhsky beishlot, the index value in 2013 was slightly higher than in the other years of the studied period.

conclusions

Thus, as a result of the work carried out, priority pollutants and indicators of the waters of the Upper Volga reservoir were identified, which include manganese, total iron, color, ammonium ion and petroleum products. The water quality of the Upper Volga Reservoir is rated as “dirty” (class 5) according to the WPI index, “moderately polluted” (class 3) according to the WPI index, and “very polluted” water (class 3, category) according to the UKIW index. "B") The use of the UKIW index provides more accurate information about the class of surface water condition, because when calculating it, all hydrochemical indicators determined in the sample are used.

Reviewers:

Zhmylev P.Yu., Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, State Budgetary Educational Institution of Higher Education "Dubna State University", Dubna.

Sudnitsin I.I., Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, State Budgetary Educational Institution of Higher Education "Dubna State University", Dubna.

Bibliographic link

The concept of water quality includes a set of indicators of the composition and properties of water that determine its suitability for specific types of water use and water consumption. Water quality requirements are regulated by the “Rules for the protection of surface waters from pollution by wastewater” (1974), “Sanitary rules and norms for the protection of surface waters from pollution” (1988), as well as existing standards. [...]

According to the nature of water use and water quality standards, reservoirs are divided into two categories: 1 - drinking and cultural and domestic purposes; 2 - for fishing purposes. In water bodies of the first type, the composition and properties of water must comply with the standards at sites located at a distance of 1 km upstream of watercourses and within a radius of 1 km from the nearest point of water use. In domestic reservoirs, water quality indicators should not exceed established standards at the wastewater discharge point in the presence of a current, and in its absence - no further than 500 m from the discharge point.[...]

Water quality is assessed according to the following parameters: content of suspended and floating substances, smell, taste, color, water temperature, pH value, presence of oxygen and organic matter, concentration of harmful and toxic impurities (Table 2.2 -2.4).[...]

Harmful and toxic substances, depending on their composition and nature of action, are standardized according to the limiting hazard indicator (LHI), which is understood as the greatest negative impact exerted by these substances. When assessing the quality of water in reservoirs for drinking and cultural purposes, three types of LPW are used: sanitary-toxicological, general sanitary and organoleptic; in fishery reservoirs, toxicological and fishery LPW are added to the above three. [...]

The water quality assessments presented above are based on a comparison of the actual values ​​of individual indicators with standard values ​​and refer to single indicators. Due to the complexity and diversity of the chemical composition of natural waters, as well as the increasing number of pollutants, such assessments do not provide a clear picture of the total pollution of water bodies and do not allow us to unambiguously indicate the degree of water quality with different types of pollution. To eliminate this drawback, methods have been developed for a comprehensive assessment of surface water pollution, which are fundamentally divided into two groups. [...]

The first includes methods that allow assessing water quality based on a combination of hydrochemical, hydrophysical, hydrobiological, and microbiological indicators (Table 2.4). Water quality is divided into classes with varying degrees of contamination. However, the same state of water according to different indicators can be assigned to different quality classes, which is a disadvantage of these methods.[...]

The second group consists of methods based on the use of generalized numerical characteristics of water quality, determined by a number of basic indicators and types of water use. Such characteristics are water quality indices and pollution coefficients. [...]

In hydrochemical practice, a method for assessing water quality developed at the Hydrochemical Institute is used. The method allows for an unambiguous assessment of water quality based on a combination of the level of water pollution based on the totality of pollutants contained in it and the frequency of their detection.[...]

Based on the value of the combinatorial pollution index, the class of water pollution is established (Table 2.5).[...]

For a comprehensive assessment of water bodies, taking into account the pollution of both water and bottom sediments, the methodology developed at IMGRE is used (Table 2.6).

10. Novikov Yu.V., Plitman S.I., Lastochkina K.S. and others. Assessment of water quality using complex indicators // Hygiene and Sanitation. 1987. No. 10. P. 7-11.

11. Guide to methods of hydrobiological analysis of surface waters and bottom sediments / Ed. V.A. Abakumov. L.: Gidrometeoizdat, 1983. 239 p.

12. Shlychkov A.P., Zhdanova G.N., Yakovleva O.G. Using the pollutant runoff coefficient to assess the state of rivers // Monitoring. 1996. No. 2.

Received by the editor on 05/03/05.

The survey of methods of a complex estimation of quality of surface waters

The survey of methods of a complex estimation of quality of surface waters resulted. The opportunity of use of some of them for an estimation of quality of water objects of Udmurtiya is considered.

Gagarina Olga Vyacheslavovna Udmurt State University 426034, Russia, Izhevsk, st. Universitetskaya, 1 (building 4)

E-mail: ogagarina@udm. ru

source of drinking water supply, characterized by a low-flow regime and subject to eutrophication processes, requires an assessment of water quality that combines hydrochemical, bacteriological and hydrobiological indicators. In this case, we give preference to the methods of the first group.

Among other things, assessing the quality of surface water also depends on the objectives of the study. If we want to get an approximate picture of chemical pollution of natural waters, then assessing water quality using WPI is really enough. If our goal is to characterize a water body as an ecosystem, then hydrochemical characteristics alone are not enough; it is necessary to introduce hydrobiological indicators.

In conclusion, it is worth noting that the use of any selected comprehensive assessment of water quality in each specific case requires additional research to more fully develop a practical and universal system for assessing the quality of natural waters.

BIBLIOGRAPHY

1. Belogurov V.P., Lozansky V.R., Pesina S.A. Application of generalized indicators for assessing the pollution of water bodies // Comprehensive assessments of the quality of surface waters. L., 1984. pp. 33-43.

2. Bylinkina A.A., Drachev S.M., Itskova A.I. On techniques for graphically depicting analytical data on the state of reservoirs // Materials of the 16th Hydrochemical. meeting Novocherkassk, 1962. pp. 8 - 15.

3. Temporary guidelines for a comprehensive assessment of the quality of surface and sea waters. Approved State Committee for Hydrometeorology of the USSR 09.22.1986

4. No. 250-1163. M., 1986. 5 p.

5. Gurariy V.I., Shain A.S. Comprehensive assessment of water quality // Problems of water protection. Kharkov, 1975. Issue 6. pp. 143-150.

6. Drachev S.M. Combating pollution of rivers, lakes, and reservoirs with industrial and domestic wastewater. M.; L.: Nauka, 1964. 274 p.

7. Emelyanova V.P., Danilova G.N., Kolesnikova T.Kh. Assessment of the quality of land surface waters by hydrochemical indicators //Hydrochemical materials. L.: Gidrometeoizdat, 1983. T.88. pp. 119-129.

8. Zhukinsky V.N., Oksiyuk O.P., Oleinik G.N., Kosheleva S.I. Criteria for a comprehensive assessment of the quality of surface fresh waters // Self-purification and bioindication of polluted waters. M.: Nauka, 1980. pp. 57 - 63.

9. Methodological basis for assessing anthropogenic influence on the quality of surface waters / Ed. A.V. Karausheva. L.: Gidrometeoizdat, 1981. 175 p.

Depending on the values ​​of complex estimates of W, the authors propose 4 levels of pollution of water bodies (see Table 4).

Table 4

The degree of pollution of water bodies depending on the values ​​of complex indicators W, calculated based on limiting signs of harmfulness

Pollution level Pollution criterion based on complex assessment values

Organoleptic W) Sanitary regime TO Sanitary-toxicological ^st) Epidemiological TO

Valid 1 1 1 1

Moderate 1.0 - 1.5 1.0 - 3.0 1.0 - 3.0 1.0 - 10.0

High,0 2, 1.5 3.0 - 6.0 3.0 - 10.0 10.0 - 100.0

Extremely high > 2.0 > 6.0 > 10.0 > 100.0

The advantage of this technique is not only a more complete accounting of hydrochemical indicators of water quality, but also the fact that, unlike the above-mentioned indicators of WPI and CIZ, in this case bacteriological indicators are also taken into account. This is especially important for reservoirs for domestic, drinking and recreational purposes. However, when assessing water quality using this method, two points attract attention: firstly, there is no clear definition of priority indicators of microbial pollution. Most likely, for reservoirs that are sources of drinking water supply, such as the Izhevsk Pond, the following can be proposed as such: the number of thermotolerant coliform bacteria, the number of coliphages, the presence of pathogens of intestinal infections. Each of these indicators separately can act as an epidemiological criterion. Secondly, the authors offer only 4 gradations of pollution levels, which is not always sufficient when working with water bodies (or areas thereof) with different levels of anthropogenic load.

In conclusion, I would like to emphasize that when developing comprehensive indicators of water quality, one must proceed from the characteristics of the hydrological regime, climatic and soil conditions of the catchment area, as well as the type of water use. So, for the Izhevsk reservoir, which is

water quality class. Thus, an incomprehensible situation arises - either we enter into the calculation all the hydrochemical indicators for which there are water tests, or only 5-6 especially “sore” ones for a given reservoir.

Practical experience shows that such a subjective factor as the number of ingredients used to assess the quality of water can influence the result. For water bodies experiencing significant anthropogenic influence, with the introduction of a larger number of ingredients into the calculation of the CIZ, the water quality class worsens.

In our opinion, a more correct approach to assessing water quality, which would allow us to avoid subjectivity, comes down to methods where the calculations involve mandatory indicators, grouped into groups according to the limiting hazard indicator (LHI). One of these is the method of assessing water quality by Yu.V. Novikov and co-authors, who propose to calculate a comprehensive assessment of the level of pollution for each limiting sign of harmfulness. In this case, four harmfulness criteria are used, for each of which a certain group of substances and specific indicators of water quality are formed:

Sanitary regime criterion (Wc), when dissolved oxygen, BOD5, COD and specific contaminants are taken into account, standardized by their effect on the sanitary regime;

The criterion of organoleptic properties (^f), when odor, suspended substances, COD and specific contaminants are taken into account, standardized according to the organoleptic sign of harmfulness;

Sanitary-toxicological pollution hazard criterion (Wcm): takes into account COD and specific pollution, standardized on a sanitary-toxicological basis;

Epidemiological criterion (W,), taking into account the danger of microbial contamination.

The same indicators can be included in several groups at the same time. The complex assessment is calculated separately for each limiting hazard characteristic (HLC) Wc, W,/,. Wcm and W, according to the formula

W= 1 + ^---------------

where W is a comprehensive assessment of the level of water pollution for a given LPV, i is the number of indicators used in the calculation; N is the normative value of a single indicator (most often N = MPCg). If 6 i< 1, то есть концентрация менее нормативной, то принимается 6 i = 1.

Table 3

Classification of water quality of streams according to the value of the combinatorial pollution index

Quality class Quality class rank Characteristics of the state of pollution Value of the combinatorial pollution index (CPI)

without taking into account the number of limiting pollution indicators (LPI) taking into account the number of limiting pollution indicators

1 LPZ (k=0.9) 2 LPZ (k=0.8) 3 LPZ (k=0.7) 4 LPZ (k=0.6) 5 LPZ (k=0.5)

I slightly polluted

II - polluted (1p; 2p] (0.9n; 1,Bn] (0.Bn; 1.6n] (0.7n; 1.4n] (0.6n; 1.2n] (0.5n; 1.0n]

III dirty (2p; 4p] (1,Bn; 3.6n] (1.6n; 3.2n (1.4n; 2,Bn] (1.2n; 2.4n] (1.0n; 1.5n ]

III a dirty (2p; 3p] (1,Bn; 2.7n] (1.6n; 2.4n] (1.4n; 2.1n] (1.2n; 1,Bn] (1.0n; 1 ,5n]

III b dirty (3p; 4p] (2.7n; 3.6n] (2.4n; 3.2n] (2.1n; 2,Bn] (1,Bn; 2.4n] (1.5n; 2 ,0n]

IV very dirty (4p; 11p] (3.6n; 9.9n] (3.2n; B,Bn] (2,Bn; 7.7n] (2.4n; 6.6n] (2.0n; 5 ,5n]

IV a very dirty (4p; 6p] (3.6n; 5.4n] (3.2n; 4,Bn] (2,Bn; 4.2n] (2.4n; 3.6n] (2.0n; 3.0n]

IV b very dirty (6p; 8p] (5.4n; 7.2n] (4.Bn; 6.4n] (4.2n; 5.6n] (3.6n; 4,Bn] (3.0n; 4.0n]

IV in very dirty (8p; 10p] (7.2n; 9.0n] (6.4n; B,0n] (5.6n; 7.0n] (4.8n; 6.0n] (4.0n; 5.0n]

IV g very dirty (10p; 11p] (9.0n; 9.9n] (B.0n; B,Bn] (7.0n; 7.7n] (6.0n; 6.6n] (5.0n; 5.5n]

Next, the generalized assessment scores of all pollutants determined at the site are summed up. Since this takes into account various combinations of concentrations of pollutants under conditions of their simultaneous presence, V.P. Emelyanova and co-authors called this complex indicator the combinatorial pollution index.

Based on the value of the combinatorial pollution index and the number of water quality ingredients taken into account in the assessment, water is assigned to one or another quality class. There are four classes of water quality: slightly polluted, polluted, dirty, very dirty. Since the third and fourth classes of water quality are characterized by wider ranges of fluctuations in the value of IPC than the first and second ones and significantly different water pollution is assessed equally, falling into the same class, the authors introduce quality categories into these classes (Table 3).

Ingredients for which the total score is greater than or equal to 11 are identified as limiting contamination indicators (LPI).

In cases where water is very heavily contaminated with one or more substances, but has satisfactory characteristics for the rest, when obtaining the CIZ, the high values ​​of some indicators are smoothed out at the expense of low values ​​for other indicators. To eliminate this, a safety factor k is introduced in the quality gradation, which deliberately underestimates the quantitative expressions of quality gradations depending on the number of limiting pollution indicators and decreases with an increase in the number of the latter (from 1 in the absence of LPP to 0.5 with 5 LPP). Thus, if there are limiting pollution indicators in the water of a water body, the water quality class is determined taking into account the safety factor. If there are more than five LPPs in the water, or if the CIZ value is more than 11 p, the water is characterized as “unacceptably dirty” and is considered outside the proposed classification.

So, when calculating the CIZ in comparison with the WPI, in addition to the frequency of exceeding the MPC, the frequency of exceeding the MPC is also taken into account. This very important addition, although it complicates the assessment of water quality (while simple calculations require significant processing of the material), it makes the idea of ​​the pollution of a water body logically complete.

However, as stated above, the authors of this method do not limit the number of ingredients involved in calculating the CIZ. Although, as practical experience shows, when assessing the water quality of water bodies subject to high anthropogenic load (rivers and reservoirs within the city), the more ingredients involved in calculating the CIZ, the worse

the following method for assessing water quality using the combinatorial pollution index (hereinafter - CPI), proposed by V.P. Emelyanova and co-authors.

The determination of KIZ is carried out according to the following formula:

where H is the generalized assessment score.

The calculation of KIZ is carried out in several stages. First, a measure of pollution stability is established (based on the frequency of cases of exceeding the MPC):

where N is the frequency of cases of exceeding the maximum permissible concentration for the 1st ingredient; NPdK - the number of analysis results in which the content of the 1st ingredient exceeds its maximum permissible concentration; N is the total number of analysis results for the ith ingredient.

Based on repeatability, qualitative characteristics of contamination can be identified, which are then assigned quantitative expressions in points.

The second stage of establishing the level of pollution is based on determining the rate of excess of the MPC

where K is the multiplicity of exceeding the MPC for the i-th ingredient; C, is the concentration of the i-th ingredient in the water of a water body, mg/l; SPdK - maximum permissible concentration of the i-th ingredient, mg/l.

When analyzing the water pollution of water bodies by the multiple of excess of standards by a particular pollutant, qualitative characteristics of pollution are identified, which are assigned quantitative expressions of gradations in points.

Combining the first and second stages of water classification for each of the ingredients taken into account, we obtain generalized characteristics of contamination, conditionally corresponding to the extent of their influence on water quality over a certain period of time. Qualitative generalized characteristics are assigned generalized assessment points B, obtained as the product of estimates for individual characteristics.

table 2

Water quality classes depending on the pollution index value

Water WPI values ​​Water quality classes

Very pure up to 0.2 I

Pure 0.2-1.0 II

Moderately polluted 1.0-2.0 III

Contaminated 2.0-4.0 IV

Dirty 4.0-6.0 V

Very dirty 6.0-10.0 VI

Extremely dirty >10.0 VII

Regarding the last condition, I would like to note the following. In the mid-90s. A.P. Shlychkov and co-authors proposed WPI taking into account water content (hereinafter referred to as WPI*). WPI* is calculated using the following formula:

A X"™4 * X-"fact

WPI * = WPI K = - £

The numerator in this expression represents the observed runoff of ingredients that make the main contribution to pollution, and the denominator is its maximum permissible runoff in an average year in terms of water content. And if the pollution of regulated river systems (for example, the Izh River) can be characterized using WPI, then on rivers characterized by a constant determination of flow rates, the calculation of the degree of pollution of a water body for a year should be adjusted for water content in a given year. Observations show that in rivers that fall under the main influence of unorganized sources of pollution located in the catchment area, in high-water years and seasons (spring) WPI* exceeds simply WPI. A different picture is typical for rivers receiving organized wastewater discharges or polluted tributaries (for which, again, the main source of pollution is organized wastewater disposal). In this case, WPI* in high-water years, on the contrary, is lower than WPI. This is explained by better dilution of pollutants entering river beds in an organized manner from permanent sources of pollution.

A clear advantage of WPI is the speed of calculations, which has made this indicator one of the most common. However, based only on hydrochemical indicators, it can be used to approximate the current state of a water body, as well as

However, in the current version of SanPiN 2.1.5.980-00 such hygienic classification is no longer available.

The second group of methods for assessing water quality consists of methods based on the use of generalized numerical characteristics - complex water quality indices. One of the most frequently used in the system for assessing the quality of surface water is the hydrochemical water pollution index (WPI), established by the USSR State Committee for Hydrometeorology. This index represents the average share of exceeding the MPC for a strictly limited number of individual ingredients (usually there are 6):

where C is the concentration of the component (in some cases, the value of the physicochemical parameter); n - number of indicators used to calculate the index, n = 6; MPC is the established standard value for

corresponding type of water body.

Thus, WPI is calculated as the average of 6 indices: O2, BOD5 and four pollutants that most often exceed the MPC. This is due to the fact that pollution of a water body can be caused by one or two substances exceeding the MPC, while the content of others is insignificant in comparison with them, and as a result of averaging we can obtain underestimated WPI values. To eliminate this shortcoming, it is necessary to take into account the priority pollutants of water bodies. For water bodies of Udmurtia, they are represented by the content of organic matter, total iron, ammonium nitrogen, petroleum products, copper, and zinc. One of the constant indices when calculating WPI is the content of dissolved oxygen. It is normalized exactly the opposite: instead of the C/MPCg ratio, the reciprocal value is substituted. Depending on the value of WPI, areas of water bodies are divided into classes (Table 2).

In this case, a requirement is established that water pollution indices are compared for water bodies of the same biogeochemical province and of a similar type, for the same watercourse (by flow, in time, etc.), and also taking into account the actual water content of the current year.

Phytoplankton biomass is a structural hydrobiological indicator; at values ​​of 5.0 g/m3, phytoplankton contributes to the self-purification of waters; higher values ​​are typical for the massive development of phytoplankton (“blooming” of water), the consequences of which are the deterioration of the sanitary and biological condition and quality of water.

The phytomass of filamentous algae gives an idea of ​​the real and potential possibility of deterioration in water quality, since the decomposition of the phytomass of filamentous algae causes water pollution with organic substances and an increase in the number of bacteria. It is estimated by values ​​for the entire area on which these algae develop.

Self-cleaning / self-pollution index (L/I). The ratio of gross production to the total destruction of plankton per day is a functional hydrobiological indicator. Low index values ​​(less than 1) indicate an excess of oxygen consumption over its production, resulting in the creation of an oxygen regime unfavorable for the processing of contaminants. Values ​​above unity characterize intensive processes of oxidation of organic matter. At the same time, when production regularly exceeds destruction (L/R>1), biological pollution occurs due to primarily produced residual organic matter.

To identify the impact on the water quality of reservoirs of industrial and domestic wastewater in a comprehensive assessment, V.N. Zhukinsky and co-authors included a biotic index scheme for assessing water quality, adopted in England. "Big

the advantages of the latter are: combined accounting of species

diversity of organisms, conversion of qualitative characteristics into quantitative ones (scores or indices), sensitivity to contaminants of unknown origin and ease of use; The disadvantage is the limitation of indicator taxa... In this regard, the column ''Indicator taxa'' is not filled in the proposed system. When using this assessment of water quality in relation to the Izhevsk Pond, the selection of indicator taxa specific to a given reservoir is required, which, however, is the field of activity of hydrobiologists and requires special consideration.

A fairly successful attempt to classify water according to the degree of pollution for water bodies for domestic, drinking and recreational purposes was also made at the level of regulatory documents. Thus, SanPiN 4630-88 provides a hygienic classification of water bodies.

comprehensive assessment of the water quality of reservoirs, and supplementing them, thereby expanding the scope of water quality assessment. One of the most successful in this area is the development of a comprehensive assessment of the quality of surface fresh waters (early version), proposed by V.N. Zhukinsky et al. It assesses the degree of pollution of a reservoir, taking into account the eutrophication of reservoirs, which is relevant for the Izhevsk reservoir. In this classification, along with hydrochemical indicators of water quality (pH, ammonium nitrogen, nitrate, phosphates, percentage of water saturation with dissolved oxygen, permanganate and bichromate oxidability, BOD5), bacteriological indicators are also used: biomass

phytoplankton and filamentous algae, self-purification index. Let us dwell on the characteristics of these important indicators.

Table 1

System of coefficients for deriving the overall value of the indicator

Indicator name Degree of pollution

Very clean Clean Moderately dirty Dirty Dirty Very dirty

Ammonium nitrogen 0 and 3 6 12 15

BOD5 and toxic substances 0 і 5 8 12 15

Total radioactivity 0 and 3 5 15 25

Escherichia coli titer 0 2 4 10 15 30

Smell 0 and 2 8 10 20

Appearance 0 and 2 6 8 10

Average total pollution coefficient 0-1 2 3-4 5-7 8-10 >10

some heavy metals (manganese, chromium), petroleum products, ammonium nitrogen, phosphates, BOD5, coli index, water odor.

Thus, the authors of the above water quality classification identified those indicators that, in their opinion, should most often be used when studying water bodies. These indicators are very necessary (one might even say urgent) to characterize the sanitary condition of water bodies in Udmurtia, especially those located in rural areas, where the main sources of pollution are either unorganized sources - surface runoff from livestock facilities and from the village, or organized ones - disposal of untreated domestic wastewater into water bodies.

A very important indicator of the sanitary condition of water bodies is the content of toxic substances. “As an indicator of the degree of pollution of water bodies by the content of toxic substances, we can take the ratio of the amount of toxic substances found analytically to the permissible concentrations, according to existing standards.”

Unfortunately, S.M. Drachev does not specify which toxic substances can act as indicators; most likely, those for which more frequent exceedances of sanitary and hygienic standards are observed. Regarding the water bodies of our republic, this may be the content of total iron, copper, zinc, chromium.

The authors of this method assign each indicator a priority - a digital value corresponding to the importance and significance of this factor. If the classification of a reservoir is ambiguous according to various indicators (the same state of water according to different indicators can be assigned to different quality classes, which is a disadvantage of these methods), then it is necessary to calculate the overall pollution indicator by averaging the numerical values ​​of conditional priorities. The coefficients for calculating the general indicator and the grouping of reservoirs by the sum of characteristics are given in Table. 1.

Despite the fact that with the help of this classification they tried to assess the sanitary state of water in reservoirs (we are not yet talking about a comprehensive assessment of water quality), one cannot but recognize the successful choice of priority indicators: E. coli titer, odor, BOD5, ammonium nitrogen and the appearance of the reservoir at the sampling site (according to the degree of oil contamination). Naturally, in almost half a century since the appearance of this classification, both knowledge in this area and technical means of monitoring water quality have expanded. Therefore, all of the above indicators can only be taken as a basis when developing

adopted in the international standard for drinking water quality (1958). The latter indicator is the ratio of the number of single-celled organisms that do not contain chlorophyll (B) to the total number of organisms, including those containing chlorophyll (A), expressed as a percentage: BPZ = 100* B / (A + B); organoleptic indicators (transparency, suspended solids content, water smell, appearance of the water surface).

the total ^-activity can be taken as an indicator, since the largest amount of analytical materials is available for this definition.”

As the main indicators A.A. Bylinkina and co-authors recommended the following five indicators: E. coli titer, odor, BOD5, ammonium nitrogen and the appearance of the reservoir at the sampling site (according to the degree of oil contamination).

Subsequently, many proposals appeared in the literature on the selection of basic indicators for assessing water quality. Some authors proposed using all indicators for which MPCs have been established. Others used a limited number of indicators in their calculations (on average 9 - 16).

The ideal option would be to use all indicators, but this is not feasible in real conditions. It is necessary to select indicators for mandatory monitoring. Almost all authors, with minor variations, agree on the following group: suspended solids, dissolved

oxygen, biochemical oxygen demand (BOD), pH, coli index, N+, N0^, chlorides, sulfates.

Proposals for a comprehensive assessment of water quality based on such a reduction of the list (or any of its expanded variants) are based on the use of the principle of representativeness, according to which pollutants are divided into two groups: representative and background. The first group is determined systematically, and the second - relatively rarely. Among the representative ones, pollutants are specially selected whose concentrations, based on local conditions, can significantly exceed the MPC. Substances of the obligatory group are considered as background (there may be 15-20 of them). For example, for the Izhevsk reservoir, located within the city and receiving industrial and domestic wastewater, as well as surface runoff from the city limits, compounds should be included among the representative ones

UDC 504.4.054 O.V. Gagarin

REVIEW OF METHODS FOR COMPREHENSIVE ASSESSMENT OF SURFACE WATER QUALITY

A review of methods for comprehensive assessment of surface water quality is provided. The possibility of using some of them to assess the quality of water bodies in Udmurtia is being considered.

Key words: water quality, water quality assessment, water quality indicators, water quality classes.

The methods that exist today for a comprehensive assessment of surface water pollution are fundamentally divided into two groups: the first includes methods that allow assessing water quality based on a set of hydrochemical, hydrophysical, hydrobiological, and microbiological indicators; the second group includes methods related to the calculation of complex indices of water pollution.

In the first case, water quality is divided into classes with varying degrees of contamination. This method in assessing the condition of reservoirs has a long history. Back in 1912 in England, a similar classification was proposed by the Royal Commission on Sewage. True, then mainly chemical indicators were used. According to external signs of pollution, water bodies were divided into six groups: very clean, clean, fairly clean, relatively clean, questionable and poor. The indicators then were BOD5, oxidizability, ammonium, albuminoid and nitrate nitrogen, suspended solids, chlorine ion and dissolved oxygen. In addition, the smell, turbidity of the water, the presence or absence of fish, and the nature of aquatic vegetation were taken into account. The greatest importance was attached to the BOD value.

In 1962 in the USSR, A. A. Bylinkina and her co-authors proposed a classification of reservoirs according to chemical, bacteriological and hydrobiological characteristics and physical properties. It was the first most advanced development in this direction, laying the foundations for the widespread six-point scale for classifying water bodies. Water quality assessment is carried out using chemical indicators (dissolved oxygen content, pH, BOD5, oxidability, ammonia nitrogen, toxic substances content); bacteriological and hydrobiological indicators (coli titer, coli index, number of saprophytic organisms, number of helminth eggs, saprobity and biological indicator of pollution, or Khorasawa index,

General characteristics of surface water quality

Characteristics of the quality of rivers in the Vologda region were carried out on the basis of materials obtained as a result of hydrochemical monitoring at 50 points, the control of which is carried out by the Vologda Central Hydrometeorological Service, and 1 production control point (JSC Severstal) on water bodies of the Vologda region:

29 rivers, Lake Kubenskoye, Rybinsk and Sheksninskoye (including Lake Beloe) reservoirs.

The assessment of water quality was carried out in accordance with RD 52.24.643-2002, developed by the Hydrochemical Institute and put into effect in 2002, "Methodological instructions. Method for a comprehensive assessment of the degree of pollution of surface waters based on hydrochemical indicators, using the UKIZV - network software package."

Based on the analysis of samples taken in 2010, it can be concluded that the surface waters of the region mainly belong to class 3 (category “polluted”) – 60% of observation points, to class 4 (category “dirty”) – 36% , to class 5 (category “extremely dirty”) - 2% of points, which is explained by the natural origin and background nature of the increased content of iron, copper and zinc in the surface waters of the region, as well as chemical oxygen demand (COD), which mainly determine the value UKIZV. At the same time, the anthropogenic component of pollution is clearly visible only in watercourses whose natural flow is significantly less than the volume of wastewater entering them (the Pelshma, Koshta, Vologda, Sodema, Shogrash rivers). 2% of points belong to class 2 (“slightly polluted” category (Figure 1.2. and Table 1.2.).

Compared to 2009, there was a decrease in the number of water bodies classified as quality class 3 (category “polluted”) with a simultaneous increase in the number of objects classified as class 4 (category “dirty”).

An analysis of possible causes showed:

In 2010, compared to 2009, the volume of contaminated wastewater decreased by 2.3 million m3, the mass of pollutants decreased by 0.6 thousand tons;

The deterioration of water quality in most cases affected water bodies, the anthropogenic influence of which is insignificant or completely absent.

Thus, we can conclude that the deterioration of water quality in the region’s water bodies is associated with abnormally high temperatures and a lack of precipitation during the summer low-water period in 2010, which led to increased oxidation processes and an increase in the share of groundwater in runoff formation. As a result, there was an increase in the content of nitrogen group substances in water, as well as substances characteristic of water-bearing soils (copper, zinc, aluminum, manganese).

Table 1.2.

Comparison of the quality of surface waters in the region based on the Integrated UKIWV Indicator for 2009 and 2010.

Figure 1.2

Figure 1.3.

Change in water quality along the length of Lake Kubenskoye - Sukhona River -
Malaya Northern Dvina river in 2009-2010

Figure 1.4

Changes in water quality along the length of Lake Beloe - Sheksninskoye Reservoir. -
Rybinsk Reservoir in 2009-2010

R. Pelshma

River water quality Pelshma for 2010 (Figure 1.5.) deteriorated within category 5 “extremely dirty” - UKIZV = 7.89 (in 2009 UKIZV = 7.29).

The main polluting ingredients are lignosulfonates and phenols, the average content of which was 14.6 MPC and 15.3 MPC, respectively. The maximum values ​​of biochemical oxygen consumption (BOD5) were observed in the summer and amounted to 83.0 MAC. The maximum content of phenols and lignosulfonates was also observed in winter and amounted to 22.3 and 21.06 MAC, respectively.

Figure 1.5.

River water quality Pelshma in 2003 - 2010

R. Sukhona in the area of ​​​​the city of Sokol and the mouth of the river. Dumplings

River water quality Sukhony above the city of Sokol, compared to 2009, improved within category 3B “very polluted” (UKIVP is 3.57), below the city of Sokol - worsened with the transition from category 3B “very polluted” to category 4A “dirty” ( UKIZV is equal to 4.34) (Figure 1.6.).

Figure 1.6.

River water quality Sukhony in the area of ​​Sokol in 2003 - 2010.

Above the river mouth Pelshma river water quality Sukhona remained within category 3A “polluted”: UKIZV2010 = 2.68, UKIZV2009 = 2.70.

Below the mouth of the river. Pelshma river water quality Sukhona also remained within category 3A “polluted” (UKIZV2010 = 2.70, UKIZV2009 = 2.81) (Figure 1.7.).

Figure 1.7.

River water quality Sukhona near the mouth of the river. Pelshma and s. Narema in 2003 - 2010

R. Vologda. The water in the river above the city (Figure 1.8.) compared to the previous year in 2010 remained in category 4A “dirty” (UKIZV2010 = 4.32, UKIZV2009 = 4.54).

Below the city of Vologda in 2010, water quality deteriorated compared to 2009 with a transition from category 4B “dirty” to 4B “very dirty” (UKIZV2010 = 6.02, UKIZV2009 = 5.54).

Figure 1.8.

Change in the quality of river. Vologda in the Vologda region in 2003 - 2010.

To a limited number of indicators that determine river water pollution. Vologda below the city and causing UKIW include ammonium nitrogen (4.1 MPC) and nitrite nitrogen (4.2 MPC), BOD5 (3.3 MPC), phenols (1.4 MPC), copper ions (4.4 MPC), nickel (1.5 MPC), iron (2.3 MPC), manganese (1.5 MPC).

Rybinsk Reservoir

Water quality of the Rybinsk Reservoir. according to the UKIWV indicator above the city of Cherepovets, it worsened within category 3B “very polluted” (UKIWV = 3.85) (Figure 1.9.).

The quality of water below the city of Cherepovets (village Yakunino) deteriorated with the transition from category 3B “very polluted” to category 4A “dirty”: UKIZV2009 = 3.31, UKIZV2010 = 4.26.

In the area of Myaksa water quality improved within category 3B “very polluted”: UKIZV2009 = 3.74, UKIZV2010 = 3.24.

The main substances that determine the value of the CIWP of the Rybinsk Reservoir are copper and iron ions, as well as COD, which are of natural origin and background in nature. In the area of Myaksa was noted for ammonium nitrogen (1.1 MPC), Yakunino BOD5 (1.3 MPC), and manganese (1.3 MPC).

Figure 1.9.

Change in the quality of Rybinsk Reservoir. in the area of ​​Cherepovets in 2003 - 2010.

R. Costa

In 2010, the water quality in the river. Koshte (Figure 1.10.) compared to 2009, remained within category 4B “dirty water” with an SCWPI of 6.11 (in 2009, a SCWPI = 6.29).

The main substances polluting river water. Koshta, were COD (2.7 MPC), nitrite nitrogen (5.7 MPC) and ammonium nitrogen (3.6 MPC), sulfates (1.9 MPC), BOD5 (2.0 MPC), nickel ions (1.7 MPC), zinc (2.8 MPC), copper (6.6 MPC), iron (2.0 MPC) and manganese (1.8 MPC).

Figure 1.10.

River water quality Koshty in the area of ​​Cherepovets in 200 3 - 2010.

R. Yagorba

Water river Yagorby (Figure 1.11.) in 2009 above the city of Cherepovets (Mostovaya village) belonged to category 4A “dirty” (UKIZV = 5.00), which is slightly higher than the level of 2009 (UKIZV = 4.93). Within the city of Cherepovets, water quality deteriorated with the transition from category 3B “very polluted” to category 4A “dirty”: UKIZV2009 = 3.75, UKIZV2010 = 4.41.

Among the main ingredients-pollutants of river water. The ions include: nickel ions (1.4 - 1.7 MPC), copper (2.3 - 3.6 MPC), iron (1.1 - 2.2 MPC), manganese (1.0 - 1.3 MPC ), BOD5 (1.4 - 2.0 MPC), COD (1.8 - 2.7), ammonium nitrogen ((1.1 MPC) and nitrite (1.5 MPC), sulfates (4.3 MPC) and petroleum products (1.6 MPC).

Figure 1.11

River water quality Yagorby in 2003 - 2010

In order to assess and identify the impact of economic activities on the quality of surface waters, the water pollution index (WPI) was also calculated, in which the concentrations of substances with elevated natural values ​​were not taken into account.

An assessment of the quality of surface waters according to the complex indicator “Water Pollution Index (WPI)” showed that in 60% of observation points in 2010 the water was classified as “clean”, in 34% - “moderately polluted”, in 4% (Koshta river – 3 km above the mouth, Vologda River – below Vologda) - polluted, 2% (Pelshma River) - “extremely dirty” (Table 1.3.).

The greatest anthropogenic load in the region is experienced by the rivers Pelshma, Koshta, Vologda below the city of Vologda, Sodema, Shogrash.

The cleanest water bodies in the region are the rivers Yug, Kubena, Chagoda, Lezha, Kunost, Mologa, Kema, Staraya Totma, B. Elma, Syamzhena, Ledenga, V. Erga, Andoga, Andoma, lake. Beloe, lake Kubenskoye, Sheksninskoye Reservoir.

Table 1.3. Comparison of the quality of surface waters in the region for 2009 and 2010.