RU2706321C2 - Method and device for treatment of aqueous solutions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to equipment related to physical and chemical methods of treatment of aqueous solutions. Primary area of use is purification of industrial and domestic effluents, household and drinking water for heat supply. Process equipment is flushed with washing solution with low or high pH. To prepare flushing solution, electrochemical reactor is connected to process equipment. Interelectrode space of the reactor is partially filled with granules of anionite and/or cationite. Reactor electrodes are connected to positive and negative poles of constant voltage source and water with neutral pH is passed at electric field intensity in interelectrode space 1 * 10² - 3 * 10³ V/m. To restore initial state of ion-exchange resins, electrodes are disconnected from voltage source and water with neutral pH is passed through electrochemical reactor chamber.

EFFECT: technical result: fast and efficient cleaning, environmental safety.

6 cl, 9 ex, 1 dwg

Description

The invention relates to the field of technology associated with the implementation of physico-chemical methods of processing aqueous solutions in order to increase the efficiency of technological processes, increase the service life of the equipment used, as well as reduce the cost, complexity and danger of its operation. Private, but very common, options for aqueous solutions, hourly processed, are consumer and process water from various sources, industrial and domestic wastewater.

In practice, the treatment of consumer water and wastewater with the aim of purifying it, heating water for heating residential buildings and industrial premises, chemical and biochemical transformation of aqueous solutions, treating water to reduce its redox potential, etc. - sooner or later, the problem arises of cleaning the working elements of the equipment used, pipelines, elements of shut-off and control valves and heat exchangers from various accumulating deposits, sludges and corrosion products.

The current level of technology is characterized by the use at the main stage of the technological process of diverse methods of carrying out chemical, physico-chemical and physical transformation of water and various aqueous solutions in various working chambers of chemical-technological equipment operating on various principles and having a different design. In this case, the chambers can be filled or not with various fillers - granular or porous filtering, sorbent materials, heating elements or electrodes (see Dytnersky Yu.I. Processes and apparatuses of chemical technology, parts 1, 2. - M .: Chemistry, 1995).

The key to the normal operation of technological equipment and any auxiliary engineering equipment connected to it (vessels-collectors of target fractions, pipelines and heat exchangers, etc.) is the correct and timely execution of another stage of the complex process of processing liquids - maintaining the purity of the internal surfaces of the working chambers of the apparatus and filling their materials, pipelines, as well as the absence of corrosion deposits on the metal elements of equipment in contact with the working environment . Thus, maintaining the operability of technological devices during their operation is no less important than ensuring the effectiveness of the physical and chemical transformation of the treated aqueous solutions. But, in our opinion, insufficient attention has been paid to the level of technical solutions to this problem — the problem of flushing equipment, fillers of working chambers, pipelines and elements of shut-off and control valves installed on them. For this reason, when considering algorithms for the technological processing of aqueous solutions in general, this application focuses on the stage, which is generally less developed - the stage that ensures the maximum operability of technological equipment.

Most often, for washing equipment, aqueous solutions with acidic properties (for removing mineral deposits, sediments and scale) or basic properties (for cleaning systems in which grease, oil and oily deposits), i.e. solutions with low or high pH, are used. In this case, the factor of low or high hydrogen index (pH) in most cases is crucial, and the nature of acidic or basic residues most often does not play a significant role.

Such washing methods necessarily include the use of containers (tanks) for placement or preparation of solutions of the necessary reagents in them. From containers, solutions of acids or alkalis are fed into the washed communications by means of pumps, the pressure of the water flow in pipelines or by gravity due to the pressure of the liquid column. Flushing devices may be provided with metering and mixing mechanisms for water and / or reagents. Sometimes flushing fluids become saturated with air or steam bubbles. Accordingly, in the framework of this methodology, various devices are currently being used that differ in the specific design of the tanks, dispensers, mixers and flow inducers, their number and connection schemes. In particular, a number of methods are known for cleaning containers and metal surfaces from harmful contaminants. Devices for implementing this method differ in technical details that do not, however, change the fundamental approach to the problem. Used washing containers with various liquids (French patent 2611148, 1988; US patent 4710232, 1987 and others). Methods and devices of this kind can be considered as analogues.

As a prototype of the claimed invention, a device for cleaning containers and metal surfaces from harmful contaminants according to the patent of the Russian Federation No. 2385443 can be considered. The device, like all analogues, contains a tank designed to feed the system with water and to prepare a chemical solution in them. The tank connected to the water source has a hatch for filling the reagent and a conical bottom. The tank is connected to a circulation system, including a network pump, a circulation pump, a suction, discharge and return piping, as well as a bypass for circulating the washing solution. The hydraulic circuit with measuring instruments and valves is controlled by an electric switchboard.

The prototype has a common drawback with all its analogues, namely, for the implementation of the applied cleaning method, transportation, storage, storage, dilution or dilution of reagents, which are usually aggressive if they come in contact with other objects dangerous to humans: toxic and harmful, are necessary in contact with the external and internal surfaces of the human body. Therefore, when implementing the known method using known devices, one has to pay the most serious attention to measures to ensure safety at work with harmful chemicals, to conduct training sessions, it is necessary to provide periodic medical examination of personnel dealing with acids and alkalis. All of the above leads to additional operating costs for the flushing operation, in any case associated with the hazards of industrial injuries, and, therefore, with additional measures to comply with safety requirements. Flushing the containers leads to contamination of the flushing fluids, which requires subsequent cleaning. In the end, an obvious drawback of the known methods of water treatment is that in practice their potential effectiveness is not achieved, the target indicators of technological processes are reduced. Given these circumstances, operators often try to perform washing procedures as little as possible, which inevitably increases the cost of washing in the future and, nevertheless, leads to a decrease in the operational performance of the main technological equipment.

The objective of the invention is to create a more efficient method and corresponding devices for its implementation, devoid of these disadvantages. The stated problem is solved using the method, which consists in the fact that in line with the main technological module and / or pipelines instead of a tank, auxiliary devices, chemicals and their solutions of acidic or basic nature, include a closed electrochemical reactor filled with granules of ion-exchange resins - converter pH When a pH converter is supplied with neutral pH water, in particular plain tap water, at its inlet, an acidic or alkaline solution can be supplied to the washed communications and containers, depending on the nature of the filler used — anion exchange resin or cation exchange resin in salt form. To ensure the process of converting water into an acidic or alkaline solution, a constant voltage is applied to the reactor electrodes from an external EMF source, which ensures the electric field strength in the interelectrode space in the range 1⋅10 ² - 3⋅10 ³ V / m. When voltage is applied to the electrodes of the reactor, hydrogen and hydroxyl ions are formed on them, which are sorbed by the ion-exchange resin in salt form. So, anion exchange granules located between the electrodes adsorb hydroxyl anions from water, and the solution is accordingly enriched with hydrogen ions, which leads to a decrease in pH, i.e. acidified water. If the reactor is filled with granules of cation exchange resin sorbing hydrogen ions, then the pH of the water increases, and the solution acquires the basic properties. A similar picture can occur when filling the interelectrode space with a mixture of cation exchanger and anion exchanger, taken in various proportions. In this case, the resulting pH value depends on the type of prevailing ion exchanger.

At relative volumetric flow rates of water in the interelectrode space in the range from 1 h ^-1 to 1⋅10 ² h ^-1 . it is possible to obtain washing solutions of acids and bases over the entire pH range of practical interest. By changing the voltage at the electrodes and the speed of the water flow through the reactor, it is possible to adjust the pH of the washing solution, obtaining values in the range from 1 to 13. It is possible to set water treatment modes that provide pH values that fall outside the specified range, but this does not make practical sense.

The neutral reaction of the ion-exchange resin (regeneration) is restored during the implementation of this method by removing the voltage between the electrodes of the reactor and passing water through it with space velocities from the above range and with a pH close to neutral, for example, tap water, up to comparing the output pH values and entrance.

At the same time, the use of the proposed invention makes it possible to realize the most economical and quickest option for acid or alkaline washing, when the final neutralization of the main technological device with water is accelerated by passing the solution of the opposite reaction formed during the regeneration of the ion-exchange resin in an electrochemical reactor. So, after acid generation, alkali is formed in the reactor during ionite regeneration and vice versa.

The proposed method is proposed to be implemented using a device whose hydraulic circuit is shown in FIG. 1. The scheme contains: technological module 1, with the help of which the aqueous solution is processed by changing the chemical composition, physico-chemical or physical state of liquids; pH converter - module 2, which is an electrochemical reactor filled with ion-exchange resins and a power supply unit - 3, and, if necessary, automatic control of the system. As technological module 1, heating devices, membrane filtration modules, sorption and precipitation filters, water electro-conditioners, dialysis, electrodialysis modules, preparative chromatography units, etc. can be used. devices. Modules 1 and 2 are interconnected by a switching system that includes pipelines and the main group of valves 4-14, which allow directing water directly or through process module 1, or through a pH 2 converter, depending on the stage of the water treatment process. Using valves 4-14, the flow direction is switched through modules 1 and 2 from direct when processing aqueous solutions to the opposite - when washing. There are also auxiliary valves 15-22, which are designed for pre-setting the system or maintenance. Using valves 15-22, the required water flow rates are established along the lines on which they are installed, as well as sampling during adjustments and control operations. In the diagram of FIG. 1, valves 4-14 are shown in the embodiment of electrically controlled solenoid valves, which ensures the implementation of the process without operator intervention - by using the automatic process control algorithm using a controller installed, like the power source, in the electric control cabinet. The circuit also contains control pressure gauges 23 and 24, a flow sensor 25 for automatically turning on the system when the solution is supplied, and two safety elements: a mechanical filter 26 and a check valve installed on the drainage line 27.

When the installation is out of operation and the P3 flow transmitter does not receive a signal, valves 4 and 8 are closed. At the beginning of operation, the signal of the transmitter 25 opens the valves 4, 8 and the source water is sent for processing to module 1. The process lasts in accordance with the adopted technological regulations. In this case, valves 5, 6 and 7 are closed.

If necessary, flush the process module 1 in the opposite direction, valves 4, 7 and 8 close and open valves 5 and 6.

During periodic washing of module 1 with a solution with an increased or decreased pH formed in module 2, voltage from module 3 is applied to its electrodes, valves 4, 5, 7, 8, 11 and 12, 14 are closed and valves 6, 10 and 13 are opened. After washing with an acid or alkaline solution, valves 4, 7, 8, 11, 14 are closed, valves 5, 10, 13 are also closed, and neutral pH water (tap water) is passed through the converter until the pH of the outlet water will not take a stable value equal to the input pH.

When using insufficiently pure water for regeneration, a situation may arise when it will be necessary to flush the pH converter in the opposite direction. Such washing is carried out by closing the valves 10 and 13 and opening the valves 9 and 11.

The practical applicability and features of the proposed method and device are illustrated by the following seven examples based on the experiment. These examples are illustrative and do not demonstrate the only possible applications of the proposed method and device.

Example 1. Decentralized heating of water in conditions of individual water use.

It is possible to implement a method of water treatment in the variant of heating the latter (changing the physical state of water) with minimizing heat loss due to the formation of sediment on the elements of the heater and improving the quality of heated water by reducing scale deposits and the formation of iron oxides on the working elements and pipelines of the hot water supply network. As a heating device, a storage water heater manufactured by OSO (Norway) of the RW-100 type with a capacity of 100 l after 6 months is taken. operation.

An acidic wash solution is prepared by passing water through a pH converter. As the latter, a commercially available Elekon-4 electric air conditioner (manufacturer - ElectroEcoTechnology LLC) is used, which is an electrochemical reactor that is made according to the RF patent for utility model No. 80840 (claim 1 of the utility model formula) and is equipped with a coaxial electrode system, and also an automatic gas vent valve. Using standard connecting elements and shut-off and control valves, the pH converter of the water is connected to the hot water supply pipe. The reactor is filled with anion exchange resin AB-17-8. The volume of the filler is about 60% of the volume of the working chamber, that is, 3 l of resin in chloride form. The washing solution is supplied to the pipes and the heater, having previously disconnected it from the energy source, is carried out at a water speed through the converter 101 h ^-1 due to the pressure in the centralized cold water supply line at the voltage on the electrodes, providing a field strength of 3.3⋅10 ³ V / m . The system is filled with a solution with a pH of 1.5 and paused for 30 minutes, after which the system is washed with ordinary tap water at a disconnected voltage on the converter electrodes. Water flushing is continued for 40 minutes, and the boiler is turned on again, and the water heating process is carried out with the best performance indicators.

As a result of using the proposed method of water treatment and a device for its implementation, the specific energy consumption for heating water can be reduced by 13% and the quality of heated consumer water can be improved by reducing the concentration of iron ions in heated water from 0.3-0.4 mg / dm ³ to 0.20-0.25 mg / dm ³ .

Example 2. Centralized water heating for hot water supply and heating of the population

It is possible to process network water by heating it in a thermal power plant system. The purpose of under-treatment is to produce water heated to 70 ° C with a minimum iron content, which inevitably enters the network water due to corrosion of boiler equipment, heat exchangers and pipelines. The iron concentration in this case can reach 3-4 mg / dm ³ , turbidity 2-3 mg / dm3, color 12-15 degrees. For the treatment of water containing up to 0.7% of petroleum products, with the aim of its comprehensive purification according to a wide range of indicators to the level of drinking standards, the serial model of water electric conditioner "Cascade" AVE-32/300 (manufacturer - LLC ElectroEcoTechnologies) is used, which is an electrochemical reactor with a diameter of 640 mm with plane-parallel electrodes (made according to paragraph 4 of the utility model formula, according to RF patent No. 80840). However, the effective removal of iron from water is hindered by the high water hardness of more than 8 gqeq / dm ³ , as a result of which a precipitate gradually forms on the cathodes of the air conditioner, on which an additional potential drop occurs, the effective field strength in the air conditioner decreases, and the concentration of iron in water increases up to the original level. To eliminate these phenomena, a pH converter according to the scheme of FIG. 1 is connected to the air conditioner AVE-32/300 using pipelines and electrically operated valves. 1, as in example 1. At intervals of 3 weeks, using the electrically controlled valves, the air conditioner is switched to washing with a solution of pH 2.3 generated by a pH converter filled with Dowex "Marathon" anion exchange resin. The passage speed of the converter electrode chamber solution is 70 h ^-1 , the field strength between the electrodes is 97 V / m. As a result, throughout the entire seasonal cycle of operation of boilers, the iron concentration in the network water is stably maintained at the target level of 0.15-0.25 mg / dm ³ , which would be impossible using known water treatment technologies. The same applies to other indicators that now meet the requirements of SanPiN 2.1.4.1074-01 "Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control. Hygienic requirements for ensuring the safety of hot water systems "

Example 3. Purification of storm water from a business enterprise.

The conditions of the experiment in examples 1, 2 can be somewhat modified in the variant of chemical-technological treatment of wastewater. So, for cleaning storm water runoffs of a car fleet in order to remove suspended particles, iron, manganese ions and oil products from it after oxidation of divalent iron ions with air oxygen, a standard precipitation filter RFM (manufacturer - ATOLL INDASTRIAU) with a diameter of 400 mm is used (see Fig. 1 , pos. 1) filled with quartz sand with a grain size of 0.3-0.6 mm. The filter is equipped with an injection aerator. Through a system of pipelines and electrically operated valves, an electrochemical reactor is connected to the filter pos. 1, as in example 1, into which about 60% of the volume of the Purolite A-100 chloride anion exchange resin is loaded. With an increase in pressure at the inlet of the filter by 0.2 MPa, due to contamination of the filter media, the drainage treatment is stopped using valves and a pH converter is connected to the filter to wash it; the potential difference is supplied to the electrodes, which provides a field strength of 1.4⋅10 ³ V / m. As a pH converter, use the standard CASCAD AVE-07/40 water air conditioner with plane-parallel electrodes (the manufacturer of ElectroEcoTechnologies). The electric air conditioner is filled with a mixture of ion exchange resins KU-2 and AVE-17 in a ratio of 1: 2 at 50% of the working volume, turning it into a pH converter As a result of passing water through the converter at a relative flow rate of the order of 40 h ^{−1, the} pH decreases to 1.8, and the working filter and communications are filled with this solution. After 40 minutes the voltage is disconnected from the converter electrodes, and the filter is flushed with tap water. The pH of the solution rises smoothly from 1.8 to 6.5 - the value characteristic of the incoming tap water, and the electric air conditioner with the help of electrically operated valves again switches to the drainage treatment process.

The efficiency of the technological process of wastewater treatment from the production facilities of the auto fleet in the variant of the long-term (six-month or more) regular treatment of storm drains is significantly increased. Without washing the filter with a solution with a pH of 1.8 after 24 hours of operation, the degree of purification decreases: for turbidity from 1.6 to 3.5 mg / dm ³ , for iron from 0.3 to 1.3 mg / dm ³ and for petroleum products with 0.6 to 3.2 mg / dm ³ . After acid washing, the cleaning efficiency increases to the initial level.

Example 4. Integrated water purification from natural sources contaminated with oil products.

To remove contaminants from water and reduce its redox potential, an electric water conditioner is used, as part of the device as in examples 1-2 according to the scheme shown in FIG. 1. Gradually declining, with prolonged use - for 1-2 months. the cleaning resource (cleaning efficiency) of the apparatus drops to a level that reaches an average of 50-60% of the initial value for various indicators. In order to regenerate the filler of the air conditioner and clean its electrodes of organic (hydrocarbon) contaminants, the apparatus is washed with a solution with the main reaction (pH 12.5). Acid washing is not required in this case, since the source water does not contain significant quantities of hardness salts. Carrying out water purification through module 1 (Fig. 1) according to the usual technological regulations, to flush module 1 in line with it through a system of pipelines and electrically controlled valves, a pH 2 converter with a coaxial electrode system is connected, as in examples 1-3. The converter reactor is filled to 60% of the volume with KU-2 cation exchange resin. Having created a tension (0.9 ÷ 1.0) ⋅10 ² V / m between the electrodes of the pH converter, an alkaline solution with a pH of 13, generated at a flow rate through the pH converter of 1.1 h ^-1 , is supplied to the electric air conditioner. Thus, the electric conditioner is washed with modified tap water for 30 minutes, disconnecting it from the electrical network, and another 30 minutes. - with a de-energized pH converter. At the end of the washing process of the claimed method, the initial efficiency of purification of contaminated water using an electric air conditioner is restored to its initial level.

Example 5. Deferrization of hard water.

To treat water with a hardness of 9.7 mg eq / dm ³ and an iron content of 3.3 mg / dm ³ with the purpose of iron removal, a precipitation filter with a diameter of 640 mm filled with catalytic sorbent brucite Mg (OH) ₂ , a natural crystalline magnesium oxyhydrate, which contains up to 69% MgO with a variable amount of impurities of silicate and carbonate minerals. During operation of the filter, cementing of the charge occurs due to the formation of magnesium carbonates on the surface of brucite grains and, as a result, a decrease in the cleaning efficiency. With prolonged use without acid washing, the cleaning process with the required performance may stop altogether.

Magnesium carbonate can be destroyed in an acidic environment. For this, a pH converter (see Fig. 1) with a coaxial electrode system, as in examples 1-2 and 4, filled with, however, anion exchange resin AB-17, is connected to the filter 1. When the system switches to flushing, every 10 days a voltage is applied to the electrodes, which ensures a field strength between them of 2.5⋅10 ² V / m. Water is passed through the converter at a speed of 52 h ^-1 for 1 h, the pH of the solution is 1.5. After 1 hour, the system is washed with source water at a disconnected voltage, after which the deferrization process is resumed.

As a result of the implementation of water treatment in the described way, the efficiency of the precipitation filter can be maintained at the maximum level (reduction in the concentration of iron from 3.5 to 0.4 mg / dm ³ ) throughout the entire period of operation.

Example 6. The neutralization of industrial waste.

The implementation of the proposed method of treatment allows you to clean the industrial waste water of a woodworking plant that contains, in addition to ecologically excessive concentrations of mineral substances, contaminants such as phenols, formaldehyde, lignosulfonic and humic acids, hydrocarbons of petroleum products and many other substances that cause extremely high values of chemical (COD) ) and biochemical (BOD) oxygen consumption - up to (3-10) ⋅10 ³ and (2-3) ⋅10 ² mg О ₂ / dm ^3, respectively.

To neutralize such multicomponent wastewater, an electric air conditioner AVE-32/300 is used, which ensures their comprehensive purification from pollution. A factor that significantly reduces the efficiency of wastewater treatment during long-term operation, as with other types of technological equipment, is the formation on the granules of the filter material and electrodes of deposits of substances that are extremely difficult to remove using conventional methods. For periodic cleaning of the filter material and electrodes, the circuit of FIG. 1 with a pH converter for water, as in examples 1-5. Once a day for 1 hour at night, when the treatment plant stops working, the valves are switched so that a solution with a pH of 2.5, generated in a pH converter from tap water, enters through the air conditioner. The passage speed of the converter electrode chamber solution is 1.1⋅10 ² h ^-1 , the field strength between the electrodes is about 900 V / m. After acid washing, the air conditioner is washed with tap water for 45 minutes, during which 1.5 m ^{3 of} water is passed.

The application of the proposed method and device provides the necessary reduction in the level of contamination of the elements of the electric air conditioner and due to this, its estimated productivity during the purification of industrial effluents during the entire period of planned operation during which COD is reduced from 4000-4200 to 35-40 mg O ₂ / dm ³ , and MIC - from 220-240 to 8 mg O ₂ / dm ³ .

Example 7. The neutralization of production effluents (more economical mode).

The implementation of the proposed method of treatment allows you to clean the industrial wastewater of a woodworking plant, as in example 6, but with reduced water costs for flushing or in another embodiment with less environmental damage to the environment in the places where the wash water is discharged due to maintaining the pH of these waters at a level close to neutral . To neutralize the wastewater of a woodworking plant, an AVE-32/300 water air conditioner is used, as in Example 6. For the periodic cleaning of the filter material and electrodes, the circuit of FIG. 1 with a pH converter for water, as in examples 1-5. As a result, as in Example 6, COD decreases from 4000-4200 to 35-40 mg O2 / dm3, and MIC - from 220-240 to 8 mg O2 / dm3. Once a day at night, when the treatment plant stops, the valves are switched to flush the air conditioner so that a solution with a pH of 2.5 generated in a pH converter from tap water flows through it. The passage speed of the converter electrode chamber solution is 1.1⋅10 ² h ^-1 , the field strength between the electrodes is about 900 V / m. After an acid washing of the air conditioner lasting 1 h, the voltage is disconnected from the pH converter electrodes, and the tap water passed through the converter acquires alkaline pH values in the range 11-12, which allows the solution to be used to neutralize acid runoff, as well as residual acid on internal elements working chamber of an electric air conditioner. As a result, a solution with a pH close to 7.0 enters the discharge. Washing is continued for 15 minutes, during which 0.5 m ^{3 of} water is passed, which is more economical in terms of water consumption (compared to Example 6) and absolutely environmentally friendly from an environmental point of view.

Example 7. Purification of water from a surface natural source containing elevated concentrations of silicon and organic substances.

Water was treated from a natural surface source (lake) by membrane cleaning using an ultrafiltration unit PRO-800 ("AquaPro") manufactured by the English company "AQUAPRO INDUSTIAL CO., LTD". Due to the rapid formation - within 24-48 hours on the membranes of sediment SiO ₂ , hydrocarbons, petroleum products, and other organic substances that pollute the lake, the specific productivity and filtering selectivity by the end of this period falls by two or more times. In order to regularly restore the efficiency of the filtration process, the ultrafiltration unit is combined with a pH converter according to the scheme of FIG. 1. For washing, an alkaline solution with a pH of 11 is used. In this case, the removal of silicon dioxide is carried out in accordance with the chemical equation:

2NaOH + SiO ₂ = Na ₂ SiO ₃ + H ₂ O

The remaining components at the above pH value simply dissolve and are removed by the flow of an aqueous solution from the ultrafiltration module.

To provide a pH of 11 of the backwash solution, the pH converter, as in Example 4, is filled with KU-2 cation exchanger. Once a day for 2 hours at night, when the filtration unit is not working, the valves of the system are switched so that a solution of pH 11 generated in a pH converter from tap water is passed through an electric air conditioner. The speed of passage of the solution of the electrode chamber of the converter is set at about 0.5 около10 ³ h ^-1 , the field strength between the electrodes is about 780 V / m.

As a result, the maximum level of water purification is stabilized at the required level, namely: oxidizability - up to 4-5 mg О ₂ / dm ³ and turbidity - up to 1.2-1.4 mg / dm ³ .

Example 8. Purification of water from a surface natural source containing elevated concentrations of hardness salts, iron and chlorides.

For the treatment of water with a hardness of 11.2 mg⋅eq / dm3, iron content of 9.8 mg / dm3 and chlorides of 470 mg / dm3 in order to reduce the content of hardness salts, iron and chlorides, a precipitation filter with built-in electrodes is used - water electric air conditioner AVE-32 / 300 filled with quartz sand. During operation of the filter, cementing of the charge occurs due to the formation of calcium and magnesium carbonates on the surface of the cathodes and grains of quartz and, as a result, a decrease in the cleaning efficiency. With prolonged use without acid washing, the cleaning process with the required performance may stop altogether.

The electrochemical reactor, which alternately performs the functions of either a pH converter or an ion exchange filter, is made on the basis of the AVE-07/40 air conditioner, as in example 3, but in this case it is 50% filled with a mixture of cation and anion exchange resins in a proportion of 1.0 : 2.0. Due to this, at the stage of the target water treatment process, the water passing through the reactor is partially demineralized, being released mainly from calcium and magnesium cations, which determine the hardness of water, as well as iron cations and chlorine anions. Water coming from the ion-exchange reactor at a rate of 38 h ^-1 for 3 hours is fed to an AVE-32/300 electrostatic precipitator (electric air conditioner), in which it is further deferred, but without deposit formation on the cathodes and cementation of the quartz filler sand. After 3 hours, an electric voltage is applied to the electrodes, providing a field strength between the electrodes of about 1.2⋅10 ³ V / m. In this mode, water with a pH of 2.4 is supplied to the washing of the electric air conditioner and within 1 hour actively traces traces of hardness salts and contaminants from iron hydroxides from it, preventing solid deposits from forming from them.

As a result of the water treatment in the described way, the efficiency of the precipitation filter can be increased both in terms of purification (reduction in the concentration of iron from 9.8 to 0.2-0.3 mg / dm ³ , of chlorides from 470 to 50-70 mg / dm ³ , hardness salts - from 11.2 to 3.5 mg ⋅ eq / dm ³ ), and for the stability of the degree of purification over a long time - 1 year or more during the entire period of operation of the equipment.

Claims (6)

1. A method of washing technological equipment for treating consumer water and wastewater with a washing solution with a lowered or increased pH, characterized in that an electrochemical reactor is connected to the technological equipment for the preparation of the washing solution, the interelectrode space of which is partially filled with anion exchange resin and / or cation exchange resin, and the reactor electrodes are connected with positive and negative poles of a constant voltage source and pass water with a neutral pH at an electric The field in the interelectrode space is 1 * 10 ² -3 * 10 ³ V / m, and to restore the initial state of ion-exchange resins, the electrodes are disconnected from the voltage source and water with a neutral pH is passed through the chamber of the electrochemical reactor. 2. The method according to p. 1, characterized in that the preparation of the washing solution is carried out in two stages, at the first of which, at a voltage applied to the electrodes, a solution with a target pH value is generated, and at the second stage, when a ion-exchange resin is regenerated, a solution with a pH value is generated, providing full or partial neutralization of the washing solution used in the first stage. 3. The method according to p. 1, characterized in that the de-energized electrochemical reactor is connected to the processing equipment at the stage of processing consumer water and waste water, and when washing the processing equipment, voltage is applied to the reactor electrodes, and before the stage of processing consumer water and waste water, ion-exchange resins, washed with an aqueous solution with a neutral pH. 4. A device for washing technological equipment for the treatment of consumer water and wastewater with a washing solution with an increased or lowered pH by the method according to paragraphs. 1-3, characterized in that it contains an electrochemical reactor for preparing a washing solution of water, the interelectrode space of which is partially filled with granules of anion exchange resin and / or cation exchange resin, switched with a voltage source and connected to technological equipment. 5. The device according to claim 4, characterized in that it is equipped with a system of pipelines and elements of shut-off and control valves, providing the possibility of alternating use of an electrochemical reactor with ion-exchange resins as an additional module for ion-exchange processing of consumer water and effluents or a module for converting the pH of the washing solution. 6. The device according to claim 4 or 5, characterized in that the heating equipment, membrane, sorption, precipitation filters and / or water electric conditioners are used as technological equipment for treating consumer water and wastewater.

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