The use of water in industrial life. Use of recycled water. Water in the chemical industry

WATER IN INDUSTRY

The whole appearance of our Earth, the emergence and development of life, all aspects of human existence are closely related to water and its specific properties.

The main reserves of water are concentrated in the oceans. For the industrial and domestic needs of mankind, only fresh water is used, which makes up about 3% of all its reserves.

At present, due to the significant development of industry and Agriculture The world is facing a serious problem caused by the continuous decrease in the amount of fresh clean water and the ever-increasing number of domestic and industrial Wastewater. The shortage of fresh water is also due to the intensive development of new water-consuming industries. For example, if for the production of 1 ton of steel 600 m 3 of water is consumed, then for the production of 1 ton of synthetic fibers it is 8 times more. Daily water consumption per capita in large cities of the USA and Europe is 600 - 700 liters, and in developing countries - 50 liters. A large amount of water is consumed by irrigated agriculture, energy, etc.

Exclusively importance currently acquires rational use of water resources. It is necessary to introduce everywhere a mode of saving water resources, to drastically reduce the emission of wastewater, to carry out their deep purification, to switch to low-water-consuming or anhydrous technological processes (i.e., working in solvents, melts and the gas phase). In addition, strict accounting and control of water consumption, reduction of water consumption for evaporation in the southern regions, prevention of pollution of the most valuable freshwater lakes (such as Baikal) also contribute to rational use water resources.

It is necessary to use more widely repeated and circulating water supply at enterprises of all branches of industry. At the same time, fresh water is taken only to replenish irretrievable losses, the discharge of wastewater is stopped, and the so-called “circulating water” that has been purified enters the technological process in a closed cycle. Circulating water supply systems can also be used in agriculture. Very promising is the use of domestic wastewater for irrigation of agricultural crops (in "irrigation fields"). In regulating the water regime of rivers and protecting them from shallowing, the role of water protection forests is especially great.

The main source of water in industry is natural fresh water. By origin, they are divided into surface (rivers, lakes), atmospheric (atmospheric precipitation) and underground (key, artesian, mineral). All waters contain a large number of impurities: calcium, magnesium, sodium, potassium carbonates, as well as sulfates, chlorides, etc. Water containing less than 1 g of salts per 1 kg of water is called fresh, more than 1 g of salts is salty. The water contains dissolved gases: oxygen, carbon dioxide CO 2, as well as hydrogen sulfide, nitrogen oxides, oxygen sulfur compounds; water may contain bacteria, impurities of sand, clay (aluminosilicates, silicates, hydrated silicic acid).

Depending on the purpose, water is conditionally divided into industrial and drinking water. Naturally, the requirements for the composition of water significantly depend on the destination. The main indicators of water quality are hardness, total salinity, transparency, oxidizability, taste, smell, reaction of the environment. To assess drinking water, the toxicity of impurities, the number of microbes contained in it, smell, color and taste are of great importance. For industrial waters, important indicators are hardness, salinity, the amount of dissolved gases and mechanical impurities. The total salt content characterizes the presence of mineral and organic impurities in the water. Their number is determined by the dry residue (mg) by evaporation of 1 liter of water and drying the residue at 110°C to constant weight. For most industries, the main quality indicator is water hardness, due to the presence of calcium and magnesium salts in water. There are three types of water hardness: temporary, permanent and general. Temporary(removable hardness) is due to the presence of calcium and magnesium bicarbonates in water. These salts are relatively easily removed by boiling. Permanent hardness due to the presence in the water of sulfates, chlorides and nitrates of calcium and magnesium, which are not removed during boiling. Temporary and permanent stiffness add up to overall hardness.

Gypsum, calcium and magnesium carbonates, together with silicates and mechanical impurities present in water, as well as various salts, deposited on the inner surface of pipes and boilers, form scale. As a result, heating and premature wear of the equipment occur, and thermal conductivity decreases. The maximum allowable concentration of dissolved salts is set by the standard depending on the production in which water is used. According to the classification, depending on the content of calcium and magnesium ions, natural waters are divided into five classes: very soft, soft, moderately hard, hard, very hard.

The amount of gases dissolved in water also affects the quality of water, since carbon dioxide, oxygen, sulfur dioxide and others cause significant corrosion of pipes.

The oxidizability of water is due to the presence of organic impurities in water and is determined by the amount of potassium permanganate (mg) consumed by boiling 1 liter of water for 10 minutes.

The reaction of water (acidity and alkalinity) is characterized by the concentration of hydrogen ions pH. The reaction of natural waters is close to neutral (pH 6.8 - 7.3). The permissible amount of impurities is also regulated by the relevant standards.

The transparency of water is measured by the thickness of the water layer through which the image of a cross or a certain font can be distinguished visually or with the help of a photocell. The most common sanitary-bacteriological indicator of water quality is the presence of microorganisms in it.

Anna Titova, Chief Water Treatment Specialist of Osmos LLC, specially for www.site

Water use in industry

In the modern world with its highly developed technologies, the quality of raw materials and products accompanying the technological process is becoming increasingly important. Most often in production processes water is used. Therefore, enterprises of various industries are faced with the task of obtaining water that meets certain requirements.

The following areas of water use in the technological process can be identified:

Water acts as a raw material for the final product. For example, in Food Industry, in the production of cosmetics, medicines, car cosmetics, etc. In this case, the quality of the resulting product and its competitive advantages directly depend on the water used.

Water is used in the technological process. For example, for waterjet cutting lines, for lines powder coating, in the electronics industry. In this case, the reliability and service life of the equipment used (usually expensive) or the quality of the resulting product may depend on the water parameters.

Water accompanies the technological process, such as circulating water of cooling, heating, air conditioning systems, etc. The service life of communications depends on its quality.

Parameters of water used in industry

Different industries have their own requirements for the parameters of the water used.

It is conditionally possible to single out the main categories according to which the quality of water is normalized.

Drinking water. Drinking water requirements Russian Federation are regulated by SanPiN 2.1.4.1074-01 “Drinking water. Hygienic requirements for water quality. Drinking water is necessary in the food industry, the production of alcoholic and non-alcoholic beverages, to meet the drinking needs of employees of enterprises.

Distilled water. The requirements for such water are set out in GOST 6709-72 Distilled water. Specifications". The main indicator that determines the quality of distilled water is its electrical conductivity, which should be no more than 5 µS/cm. The reverse electrical conductivity value can also be used - electrical resistance - for distilled water it must be at least 200 kOhm * cm. Distilled water is required in many chemical industries, laboratories, printing houses, etc.

Water deionized. The concept of deionized water is rather conditional - for different technological processes requirements for such water may be different. The main parameter against which deionized water is normalized is its electrical resistance. Depending on the purpose, it may be necessary to obtain water with a resistance of 500 kOhm * cm or more. Deionized water is used in electronic instrumentation and in many other technological processes.

Ultrapure water. Such water should not contain practically any salt ions. The resistance of ultrapure water is 12-18 MΩ*cm. Such water is used in microelectronics, crystal growth, etc.

Special purpose water, normalized by the parameters that are important for a particular technological process. For example, the concentration of any individual ions or organic substances above a predetermined value may not be allowed. Standards have been developed for water for galvanic production, for steam boilers, for aquariums and oceanariums, etc.

As we can see, different industries may require water of completely different quality. But there is one requirement common to all enterprises - this is the STABILITY of the result.

It is for this reason that membrane water treatment systems are most widely used today in industrial water treatment. The difference between such systems and traditional accumulative ones (sorbents, ion-exchange resins, iron-removing materials) is that during the filtration process they do not accumulate impurities inside themselves, but mechanically separate them. This principle eliminates the possibility of unwanted impurities entering the treated water. Thanks to this technology, even with a significant deterioration in the parameters of the source water, the quality of treated water remains consistently high.

You can read more about the membrane filtration method in the articles at http://www.osmos.ru/prom/info.html

It is possible to identify the main typical schemes of water treatment complexes:

Getting drinking water

Installation of reverse osmosis of the required performance;
Conditioning unit - filter with activated carbon loading;

Getting distilled water

Precleaner (if required)
Tanks for the supply of purified water.

In some cases (with a low salinity of the source water), it may be sufficient to use a single-stage reverse osmosis.

Such a water treatment scheme is an economically viable alternative to the previously used evaporator distillers, which consume a large amount of electricity.

Obtaining deionized and ultrapure water.

Pre-treatment unit (if required);
Installation of a two-stage reverse osmosis of the required capacity;
Tanks for the supply of purified water;
Deep cleaning unit - filters with ion-exchange resin in H + and OH- form (if required).

Due to the consistently high quality of water at the outlet of the second stage of reverse osmosis, the resource of ion exchange resins in H+ and OH-form becomes very high. Since such resins are expensive, the use of two-stage reverse osmosis units upstream of them can significantly reduce the operating costs for changing resins.

It should be noted that the “lifetime” of high-purity water is measured in seconds; upon contact with air, water instantly absorbs carbon dioxide, which, turning into hydrocarbons, lowers the electrical resistance of water. Therefore, the deep cleaning unit must be located in close proximity to the point of use of purified water.

When designing an integrated water treatment system for a specific technological process, it is necessary to take into account the analysis data of the source water, the requirements for treated water, the required daily and peak consumption of treated water, and the conditions for placing equipment.
This task is not easy, so when choosing equipment, you need to turn to professionals.

This article was prepared by Osmos.

For more than 10 years, Osmos LLC has been developing and manufacturing water treatment systems based on membrane technology, designing water treatment systems.

Use of natural waters in the Urals.

Huge volumes of water are consumed by industry, agriculture, and in Lately increased human demand for water for household needs. Now, out of 18414 rivers in the region, six rivers are included in the list of the most polluted objects of the Russian Federation - the basin of the Iset, V. Pyshma, Tura, Tavda, Chusovaya, Ufa rivers.

In industry, water is used:

For cooling and heating liquids, gases and gas mixtures;
as a solvent;
For the preparation and purification of solutions;
For transporting materials and raw materials through pipes;
For thermal power purposes, as a steam for converting heat or pressure;
For waste disposal, etc.

If in production it is necessary pure water, it is taken from the plumbing system. In cases where the water may not be particularly clean, factories and factories use river water. Such opportunities are used in most paper mills. Water consumption by industry has now reached enormous proportions. According to experts, irretrievable water consumption was about 150 cubic meters. km per year, i.e. 1% of sustainable freshwater runoff. According to calculations, the need for water on Earth until the year 2000 will increase by an average of 3.1% per year. Humans currently consume 3,000 km of fresh water every year.

Agriculture accounts for more than 2/3 of the world's water consumption, and approximately 17% of the cultivated area worldwide is irrigated. Now in the world about 15 million hectares are occupied by sown areas. quad. km.

Sustainable agriculture in the Urals requires a huge consumption of water resources, despite the fact that Sverdlovsk region has a low development of territories (no more than 13% of the entire territory). (Dvinsky V.M., Bril A.B., Vidrevich M.B. Environmental management)

Thus, the industry uses 150 km3 per year.

Use of water in industry, household and agriculture

In the structure of wastewater disposal, 35% is accounted for by all industries, except for thermal power engineering, 33% - for thermal power engineering, 18% are discharges of wastewater from reclaimed fields and 14% - discharges from municipal services of cities and rural settlements.

One of the main consumers of water is irrigated agriculture - 190 m3/year. To grow 1 ton of cotton, 4-5 thousand m3 of fresh water is required, 1 ton of rice - 8 thousand m3. Irrigation consumes most of the water irretrievably. Water consumption for irrigation depends on three factors: irrigated area, crop composition and irrigation technique.

Sprinkler irrigation is the main method of irrigation. Efficiency irrigation systems does not exceed 0.6. A lot of water seeps in irrigation canals, raising the water table and causing soil salinization. Water losses are significantly reduced when using progressive irrigation methods: drip irrigation, preferred soil and fine dispersion irrigation. Improvement of irrigation systems, concreting of the bottom, the use of closed drains help to increase the efficiency of these systems, but these methods are not yet fully used.

Municipal water consumption exceeds 20 km3/year. The level of development of municipal water supply is determined by two indicators: the provision of the population with centralized water supply and the value of specific water consumption. An important task is to reduce the consumption of tap water for technical needs. In Moscow, for example, industry accounts for 25% of tap water supplied to the capital. However, there is no need to use drinking water for technical needs. To do this, it is necessary to expand the network of technical water pipelines, which will significantly reduce the cost of consumed water.

Water consumption in industry is high (about 90 km3/year). For the smelting of 1 ton of steel, 200-250 m3 of water is required, 1 ton of cellulose - 1300 m3, ... There are great reserves for saving water in industry through the introduction of advanced technological processes. For example, in old petrochemical plants for processing 1t. oil consumes 18-22 m3 of water, while at modern plants with circulating water supply and air cooling systems - about 0.12 m3 / year.

At present, the situation is aggravated by the fact that after the privatization of the main number of enterprises, including environmentally polluted enterprises, the new owners do not have enough money to build or modernize treatment facilities.

The work was completed by student 11 V

Class, gymnasium No. 1

Solodilov Dmitry.

Water and its role in industrial production

Water is of key importance in the processes of the emergence of life on Earth and its constant maintenance, since it is water that forms the climate, and it is also necessary for the chemical processes that occur in the bodies of people and animals. The role of water in people's lives cannot be overestimated. The main consumers of fresh water are: agriculture, industry, including energy and utilities. In industrial production, the most water-intensive are chemical, pulp and paper and metallurgical industry. So, for the production of 1 ton of synthetic fiber, 2500 ... 5000 m3 of water is spent, plastics - 500 ... 1000, paper - 400 ... 800, steel and cast iron - 160 ... 200 m3 of water. For industrial purposes different sources consumes from 8 to 20% of all water used in the world, of which over 85% of water is consumed in cooling processes. The rest is consumed in the processes of washing, washing gases, for hydrotransport and as a solvent. Approximately half a million liters of water is used to release each passenger car; this quantity includes both consumable water and reused water.

At the moment, the quality of water in different regions of the country can vary greatly (it all depends on the population, rivers, runoff, the presence of large enterprises), but in general, water cannot boast high quality. To improve the quality of water treatment, it is necessary to use the most modern technologies, and make the cleaning process truly complex and conduct water treatment. In the production and release of products, the quality of water determines the characteristics of the final product. This is achieved either by removing from the water harmful to the equipment used, or finished products substances or cooling. Prepared water, after passing chemical cleaning and (or) cooling in industrial equipment, enters directly into the production cycle.

Industrial water treatment.

Water treatment is a cycle of measures for water purification, which is carried out with the help of softening, iron removal plants, as well as with the help of sorption, sedimentation plants and UV disinfectors. Using such automated equipment for industrial water treatment, it is possible to make water treatment an almost continuous process that does not slow down production and provides all stages of work with water of the required quality.

Experts identify the following main problems facing industrial water treatment: water hardness, a large number of impurities, color, swing, the presence of bacteria and viruses, and other contaminants. Industrial water treatment can include a range of purification measures. One of the main negative characteristics water is a high iron content, which affects both the operation of water-using equipment and human health (if it is, for example, the food industry), since precipitation lingers in the body for a long time and affects its daily functioning.

Industrial water treatment is not only a significant improvement in the quality of manufactured products and an extension of the service life of equipment, but also a reduction in the impact harmful substances on environment by reducing harmful runoff. The main purpose of industrial water treatment is water purification for enterprises and facilities with high water consumption per day. Water treatment, depending on the requirements of the consumer, both general and post-treatment are used. General cleaning includes cleaning of iron and hardness salts. Post-treatment is the desalination of water and its complete softening.

To provide water to enterprises that place high demands on water quality, such as medical institutions, pharmaceutical and food facilities, sports complexes and children's institutions, a multi-stage purification system is used. Now almost all food and dairy enterprises of the Russian Federation are reconstructing with the replacement of worn out or obsolete equipment with new models of imported and Russian production. In this regard, the approach to source water supplied through citywide or other water supply networks is changing significantly. general purpose, or water coming from artesian wells. The systems use reagent water treatment - to destroy dangerous microorganisms contained in water, desalination using reverse osmosis and ion exchange, as well as selective ion exchange technologies.

At especially large enterprises of heavy industry, equipment is used in technological cycles, during the operation of which it is required to cool it. For this purpose, such enterprises often use recycling water supply systems, but during the operation of these systems, problems arise with the composition of the make-up water and pollution of the wastewater from the recycling water.

iron removal- the process of rapid water purification using an iron remover, which is produced in two main variations. Special substances are poured into the reagent iron remover used in everyday life and in industrial water treatment to improve and accelerate iron removal. Reagent-free iron remover for industrial water treatment performs water treatment by the catalytic method.

In addition to iron removal, industrial water treatment is often carried out water softening which is carried out using specialized equipment. Hard water is not only contraindicated for drinking, without water treatment it also affects the operation of the equipment, as the heating elements quickly overgrow and eventually break. Water softening during industrial water treatment is carried out using the method of ion exchange, reagent softening or nanofiltration, which, even with continuous water treatment, cope with calcium and magnesium ions, which are detrimental to subsequent water treatment equipment.

Sometimes there is a need water treatment through water treatment from large residual elements, impurities or visible particles. For such water treatment, special sedimentation plants are used to remove sand, rust or other materials from tap water or water extracted from wells. That is, sedimentation technology is engaged in mechanical water treatment, which is important, for example, for utilities and various enterprises.

For a number of industries, water purification from metals and various salts is insufficient, since there is a need for full-fledged industrial water treatment with the removal of any, even the smallest impurities. For this, they are used sorption water treatment plants, specializing in the active treatment of waste and other waters from settled small particles with a size of 5 microns. This stage of industrial water treatment follows, as a rule, a coarser water purification from colloidal impurities. Sorption water treatment plants operate through the use of synthetic fibrous materials such as polyester petals and polypropylene threads.

An important step in industrial water treatment is additional purification from bacteria, viruses and other harmful elements, affecting water performance and its ability to be consumed and used in production. One of the most modern solutions to this issue has become ultraviolet lamps for industrial water treatment. This allows the use of UV disinfectors in water treatment at food processing plants, where the removal of harmful elements and water treatment are essential for simple safety and safety of the final product.

Industrial water treatment includes the importance of monitoring the acid-base indicators of water. For example, a liquid with a high pH level negatively affects equipment that breaks down with prolonged use of untreated water. Moreover, unbalanced water is harmful to health, and many chemical processes in water that has not undergone water treatment and balancing of acid-base indicators are either impossible or do not occur at full strength. Thus, pretreatment of water from acids and normalization of the pH level will ensure the safety of equipment (including other water treatment devices) and a significant improvement in the quality of the water itself.

Nowadays, the problem of water purification is becoming more and more relevant. This applies to both drinking water treatment and water treatment. industrial enterprises. Of course, different industries require one or another degree of water purification. But in any case, if necessary, get water yourself best quality, without impurities of salts and other components, ordinary filtration alone is completely insufficient.

Modern technologies based on the principle of reverse osmosis make it possible to purify water at the molecular level. And free it not only from salts, but also from all sorts of organic compounds, including viruses and bacteria. desalination of water, or demineralization, is a very important physical process of removing salts when using water in technological processes of boilers, steam generators, food, medical and other installations, to prevent scale and rapid wear of equipment. Due to desalination, water treatment reduces the concentration of salts and minerals to a predetermined value, and makes the source water suitable as a drinking, cooling, or technological liquid.

Direct osmosis is used on the use of membranes capable of passing only water molecules, while retaining all other molecules. By dividing by such a membrane, for example, two communicating vessels with more or less pure water, one can see that the water level in the vessel with less pure water will rise over time. This will happen due to the fact that only water molecules will flow through the membrane, trying to balance the concentration in both vessels. This is the phenomenon of direct osmosis. It logically follows that if pressure is created in a more "dirty" vessel, then water molecules will flow, on the contrary, into a "cleaner" vessel, making the water even purer. And this is the principle of reverse osmosis.

Thus, using such membranes together with pre-filters, it is possible to create a highly efficient water treatment system for enterprises based on the principle of reverse osmosis. In other words, the reverse osmosis process is based on the passage of water through a membrane from a more saturated salt solution to a less saturated solution under the action of a pressure that exceeds the difference in osmotic pressure values in both solutions.

Use of recycled water.

The intensive development of industry and agricultural production, the improvement in the level of improvement of cities and towns, and a significant increase in population have led to a shortage and a sharp deterioration in the quality of water resources in almost all regions of Russia in recent decades.

One of the main ways to meet the needs of society in water is the engineering reproduction of water resources, i.e. their restoration and enhancement not only quantitatively but also qualitatively.

Prospects for the rational reproduction of technological water consumption are associated with the creation of repetitive-sequential, circulating and closed water supply systems at enterprises. They are based on the amazing property of water, which allows it not to change its physical essence after participating in production processes.

The industry of Russia is characterized by a high level of development of circulating water supply systems, due to which the saving of fresh water used for production needs is on average 78%. The best indicators of the use of circulating systems are enterprises of the gas (97%), oil refining (95%) industries, ferrous metallurgy (94%), chemical and petrochemical (91%) industries, mechanical engineering (85%).

The maximum water consumption in the systems of circulating and re-sequential water supply is typical for the Ural, Central, Volga and West Siberian economic regions. In general, in Russia, the ratio of the volumes of fresh and recycled water use is 35.5 and 64.5%, respectively.

The widespread introduction of perfect water circulation systems (up to closed ones) can not only solve the problem of water supply to consumers, but also keep natural water sources in an environmentally friendly state.

Use of natural waters in the Urals.

Huge volumes of water are consumed by industry, agriculture, and recently the human demand for water for household needs has increased. Now, out of 18414 regions, six rivers are included in the list of the most polluted objects of the Russian Federation - this is the river basin - Iset, V. Pyshma, Tura, Tavda, Chusovaya, Ufa.

In industry, water is used:

For cooling and heating liquids, gases and gas mixtures;

as a solvent;

For the preparation and purification of solutions;

For transportation of materials and raw materials through pipes;

For heat and power purposes, as a steam for converting heat or pressure;

For waste disposal, etc.

If clean water is needed in production, it is taken from the plumbing system. In cases where the water may not be particularly clean, factories and factories use river water. Such opportunities are used in most paper mills. Water consumption by the industry has now reached enormous proportions. According to experts, irretrievable water consumption was about 150 cubic meters. km per year, i.e. 1% of sustainable freshwater runoff. According to calculations, the need for water on Earth until the year 2000 will increase by an average of 3.1% per year. Currently, people annually spend 3000 kmfresh water.

Agriculture accounts for more than 2/3 of the world's water consumption, and approximately 17% of the cultivated area in the world is irrigated. Now in the world about 15 million hectares are occupied by sown areas. quad. km.

Sustainable agriculture in the Urals requires a huge consumption of water resources, despite the fact that the Sverdlovsk region has a low development of territories (no more than 13% of the entire territory). (Dvinsky V.M., Bril A.B., Vidrevich M.B. "Environmental management")

The same industry uses 150 kmcube per year.

Use of water in industry, household and agriculture

Sprinkler irrigation is the main method of irrigation. The efficiency of irrigation systems does not exceed 0.6. A lot of water seeps into the irrigation canals, raising the water table and causing soil salinization. Water losses are significantly reduced when using progressive irrigation methods: drip irrigation, preferential and finely dispersed irrigation. Improvement of irrigation systems, concreting of the bottom, the use of closed drains help to increase the efficiency of these systems, but these methods are not yet fully used.

Municipal water consumption exceeds 20 km3/year. The level of development of municipal water supply is determined by two indicators: the provision of the population with centralized water supply and the value of specific water consumption. An important task is to reduce the consumption of tap water for technical needs. In Moscow, for example, industry accounts for 25% of the tap water supplied to the capital. However, there is no need to use drinking water for technical needs. To do this, it is necessary to expand the network of technical water pipelines, which will significantly reduce the cost of consumed water.

Industrial water consumption is high (about 90 km3/year). Smelting 1 ton of steel requires 200- 250 m3water, 1 ton of cellulose - 1300 m3,… The reserves of water saving in the industry due to the introduction of advanced technological processes are great. For example, at old petrochemical plants for processing 1t. oil is consumed 18- 22 m3water, while at modern plants with circulating water supply and air-cooling systems - about 0.12 m3 / year.

The work was completed by student 11 "B"

Class, gymnasium No. 1

Solodilov Dmitry.