Integrated brackish water desalination device, control method, medium, equipment and terminal

Abstract

The application belongs to the technical field of brackish water treatment, and discloses an integrated brackish water desalination device, a control method, a medium, equipment and a terminal. The integrated brackish water desalination device comprises a pretreatment unit, a displacement electrodialysis unit, a bipolar membrane electrodialysis unit and a chelating resin tank. The displacement electrodialysis unit effectively avoids the precipitation of a large amount of calcium and magnesium ions in the concentrated chamber; the bipolar membrane electrodialysis unit can produce acid and alkali, the produced acid is used for adjusting the pH value of the polar liquid to prevent the polar chamber from being scaled; the acid, the alkali and the brine are alternately used to regenerate the resin; the hard salt water provided by the chelating resin tank is supplied to the bipolar membrane electrodialysis unit, so that the bipolar membrane electrodialysis unit is prevented from being scaled, and the alkali chamber of the bipolar membrane electrodialysis unit can also be cleaned by the acid chamber. The whole system does not need to add acid and other reagents during operation, and breaks through the technical bottleneck of the development of the electrodialysis method for brackish water desalination; the internal partial circulation desalination mode is adopted in the operation process, the occupied space is saved, the operation is simple, the system is stable, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of brackish water treatment, and particularly relates to an integrated brackish water desalination device, a control method, a medium, equipment and a terminal. BACKGROUND

[0002] Brackish water refers to water with an alkalinity greater than a hardness and containing a large amount of neutral salt, and has a pH value greater than 7. In daily life, when the chloride exceeds the normal range (250 mg / L according to the national standard), it is brackish water. In China, brackish water is mainly distributed in some northern regions and eastern coastal regions, and the population of rural areas that drink brackish water has reached more than 40 million. The main components of brackish water are cations including Na + , K + , Ca 2+ and Mg 2+ ; and anions including Cl - , SO4 2- , HCO3 - (CO3 2- ) and F - . In addition, the excessive salt and impurities in brackish water are very harmful to the human body, and the root cause of many local diseases is drinking water.

[0003] The treatment of brackish water is actually brine desalination, that is, desalination of brine or reaching the standard of drinking water after treatment. There are many methods for brackish water desalination, which can be generally divided into distillation, reverse osmosis and electrodialysis. Distillation is a process of boiling and evaporating brackish water or seawater, and then condensing the steam into fresh water. There are many kinds of distillation methods, such as multi-effect evaporation, multi-stage flash evaporation, pressure vapor distillation, membrane distillation and the like. The advantages of distillation are simple structure, easy operation and good quality of desalinated water; the disadvantages are high energy consumption, high operation cost and easy corrosion and fouling. Reverse osmosis is to separate solute and solvent in the solution under the action of external force, by means of the retention of the semi-permeable membrane, so as to achieve the purpose of concentration, purification or separation. The advantages of reverse osmosis are simple equipment, normal temperature operation and low energy consumption; the disadvantages are high requirements for pretreatment of raw water, need to replace filter materials regularly according to the water quality and water requirements, and increase operation cost. Electrodialysis is to use the selective permeability of ion exchange membrane, that is, the anion exchange membrane (referred to as anion membrane) can let anions pass through but retain cations, and the cation exchange membrane (referred to as cation membrane) can let cations pass through but retain anions, under the driving of an external direct current electric field, the anions and cations migrate directionally, so as to realize the desalination of brackish water. The advantages of electrodialysis are lower energy consumption than distillation, lower requirements for pretreatment of raw water, longer running time and easy cleaning. Compared with distillation and reverse osmosis, electrodialysis is more suitable for the field of brackish water desalination.

[0004] In the process of brackish water desalination by electrodialysis, the anions and cations in the desalination chamber migrate to the concentration chamber, and the concentration chamber not only enriches Na +, K + , Cl - , etc. monovalent ions, also enriched Ca 2+ , Mg 2+ , SO4 2- , CO3 2- , etc. high valence ions, resulting in the formation of CaCO3 and CaSO4 precipitates in the concentration chamber, blocking the flow channel of the concentration chamber, forming a fouling layer on the membrane surface, affecting the treatment performance and service life of the membrane stack. In particular, CaSO4 precipitates are insoluble in acid and are difficult to remove once formed. In addition, during the electrodialysis process, electrode reactions occur, with oxidation reactions occurring in the anode chamber and reduction reactions occurring in the cathode chamber. In the field of brackish water desalination, raw water containing salt is generally used as the electrolyte; after electrification, H + , O2 and Cl2 are generated on the surface of the positive electrode (anode chamber); OH - and H2 are generated on the surface of the negative electrode (cathode chamber). Due to the presence of Ca 2+ , Mg 2+ ions or other multivalent metal ions in the raw water, the OH - generated on the surface of the negative electrode easily combines with them to form extremely insoluble Mg(OH)2, Ca(OH)2 precipitates or other hydroxide precipitates, resulting in fouling of the negative electrode chamber and blocking the flow channel; and under the action of a direct current electric field, Ca 2+ , Mg 2+ and other multivalent metal ions migrate and accumulate towards the negative electrode, further exacerbating the formation of precipitates. At the same time, OH - ions migrate towards the positive electrode, even if a positive membrane is used for the ion-selective membrane adjacent to the negative electrode, OH - ions can still pass through the positive membrane, forming precipitates in the compartment adjacent to the negative electrode and attacking the membrane stack, resulting in failure of the membrane stack.

[0005] To prevent the formation of CaCO3 precipitates in the concentration chamber, the usual measure is to adjust the pH of the concentration chamber to be slightly acidic, which requires the addition of hydrochloric acid. However, for CaSO4 precipitates, the formation of precipitates can be inhibited to some extent by "frequent electrode reversal" operation control and the addition of a scale inhibitor to the concentration chamber, but the most fundamental measure to avoid the formation of CaSO4 precipitates is to control the concentrations of calcium ions and sulfate ions in the concentration chamber, so that the product of the concentrations of calcium ions and sulfate ions is less than the solubility product of calcium sulfate, but this will reduce the water production rate of brackish water desalination. To prevent the formation of precipitates in the cathode chamber, the usual measure is to add hydrochloric acid to the electrolyte to neutralize the generated precipitates. However, as the running time increases, sufficient amounts of hydrochloric acid must be added to neutralize the OH - generated by the reduction reaction of the negative electrode. Under normal conditions, controlling the pH of the solution in the electrode water tank to be ≤3 can effectively inhibit the formation of precipitates. However, in some applications, the transportation and storage of hydrochloric acid are not easy, which becomes an obstacle to the popularization of electrodialysis brackish water desalination applications.

[0006] Through the above analysis, the problems and defects of the prior art are:

[0007] (1) In the existing desalination method of brackish water, the distillation method has high energy consumption, high operating cost and is easy to corrode and scale;

[0008] (2) The reverse osmosis method has high requirements for the pretreatment of raw water, and the filtering material needs to be replaced regularly according to the water quality of the raw water and the water requirement, thereby increasing the operating cost;

[0009] (3) The electrodialysis method causes scaling in the negative electrode chamber, blocks the flow channel of the concentration chamber and forms a scaling layer on the membrane surface, thereby affecting the treatment performance and service life of the membrane stack;

[0010] (4) Currently, adding acid to the concentration chamber to adjust the pH value consumes a large amount of hydrochloric acid, and controlling the concentration of calcium ions and sulfate in the concentration chamber seriously reduces the water production rate; in the method of adding hydrochloric acid to the electrolyte to prevent precipitation in the cathode chamber, the transportation and storage of hydrochloric acid are not easy, which hinders the popularization of brackish water desalination by electrodialysis. SUMMARY

[0011] In order to overcome the problems in the related art, the present application provides an integrated brackish water desalination device, a control method, a medium, an equipment and a terminal, and the technical solution is as follows:

[0012] The present application is implemented as follows: the integrated brackish water desalination device comprises a pretreatment unit, a displacement electrodialysis unit, a bipolar membrane electrodialysis unit and a chelating resin tank.

[0013] The pretreatment unit is one or a combination of two or more of a precision filter, a microfilter, an ultrafilter, a medicament adding unit and a disinfection and sterilization unit, and the outlet of the pretreatment unit is communicated with a raw water tank through a water conveying pipeline;

[0014] The inlets of the desalination chamber A, the desalination chamber B, the concentration chamber A, the concentration chamber B and the two electrode chambers of the displacement electrodialysis unit are communicated with the raw water tank, the sodium chloride tank, the water production tank and the electrode water tank through A pump, B pump, C pump, D pump and E pump, respectively, the outlets of the desalination chamber A, the desalination chamber B, the concentration chamber A and the concentration chamber B are communicated with the water inlet pipeline 1, the pipeline 2, the pipeline 3 and the pipeline 4 through valves, respectively, the outlet of the desalination chamber A is communicated with the water production tank, the outlets of the desalination chamber B, the concentration chamber A and the concentration chamber B are provided with liquid discharge valves, and the outlet of the electrode chamber is communicated with the electrode water tank;

[0015] The inlets of the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialysis unit and the inlet of the electrode chamber are communicated with the outlet of the chelating resin tank and the electrode water tank through G pump, H pump, I pump and E pump, respectively, the outlets of the acid chamber, the alkali chamber and the salt chamber are communicated with the water inlet pipeline 5, the pipeline 6 and the pipeline 7, wherein the outlet of the acid chamber is communicated with the electrode water tank, the outlets of the acid chamber, the alkali chamber and the salt chamber are provided with liquid discharge valves, and the outlet of the electrode chamber is communicated with the electrode water tank.

[0016] The inlet of the chelating resin tank is communicated with the raw water tank through the F pump and the water inlet pipeline 8, and the outlet is communicated with the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialyzer through the G pump, the H pump and the I pump.

[0017] In an embodiment, when the integrated brackish water desalination device is in steady state operation, the desalination chamber A, the desalination chamber B, the concentration chamber A and the concentration chamber B are all operated in the “in-device partial circulation desalination” mode; the raw water is sent into the desalination chamber A through the A pump by the water inlet pipeline 1, the valve B is partially opened, a part of the desalination chamber A effluent is recycled in the water inlet pipeline 1, and the other part is discharged into the product water tank; the sodium chloride solution is sent into the desalination chamber B through the B pump by the water inlet pipeline 2, the valve C is partially opened, a part of the desalination chamber B effluent is recycled in the water inlet pipeline 2, and the other part is discharged; the pure water is sent into the concentration chamber A through the C pump by the water inlet pipeline 3, the valve D is partially opened, a part of the concentration chamber A effluent is recycled in the water inlet pipeline 3, and the other part is discharged; the pure water is sent into the concentration chamber B through the D pump by the water inlet pipeline 4, the valve E is partially opened, a part of the concentration chamber B effluent is recycled in the water inlet pipeline 4, and the other part is discharged.

[0018] In an embodiment, when the integrated brackish water desalination device is in steady state operation, the acid chamber, the alkali chamber and the salt chamber are all operated in the “in-device partial circulation desalination” mode; the hard salt water is sent into the acid chamber through the G pump by the water inlet pipeline 5, the valve H is partially opened, a part of the acid chamber effluent is recycled in the water inlet pipeline 5, and the other part is discharged; the hard salt water is sent into the alkali chamber through the H pump by the water inlet pipeline 6, the valve G is partially opened, a part of the alkali chamber effluent is recycled in the water inlet pipeline 6, and the other part is discharged; the hard salt water is sent into the salt chamber through the I pump by the water inlet pipeline 7, the valve F is partially opened, a part of the salt chamber effluent is recycled in the water inlet pipeline 7, and the other part is discharged.

[0019] In an embodiment, the valve A1 and the valve A2 are used to guide the water in the raw water tank into the polar water tank and the chelating resin tank, respectively, the acid liquid generated by the bipolar membrane electrodialysis unit is discharged into the polar water tank through the valve I to adjust the pH value of the polar liquid.

[0020] In an embodiment, the chelating resin tank uses the acid liquid, the salt water, the alkali liquid and the salt water of the bipolar membrane electrodialysis unit to alternately flush the resin column of the chelating resin tank to regenerate the resin; the alkali chamber of the bipolar membrane electrodialysis unit is cleaned by the acid liquid of the bipolar membrane electrodialysis unit.

[0021] Another object of the present application is to provide an integrated brackish water desalination device control method for implementing the integrated brackish water desalination device.

[0022] The integrated brackish water desalination device sends the salt-containing raw water to the raw water tank after pretreatment, stops supplying raw water when the set liquid level is reached, configures a certain volume of 15% sodium chloride solution in the sodium chloride water tank, supplies a certain volume of pure water to the water production tank, opens valve A1 to make part of the water in the raw water tank flow into the electrode water tank, starts A pump, B pump, C pump, D pump and E pump to make the displacement electrodialysis unit run, at the same time, makes the raw water in the raw water tank circulate through the desalination chamber A of the electrodialysis unit by A pump, makes the sodium chloride solution in the sodium chloride water tank circulate through the desalination chamber B of the electrodialysis unit by B pump, makes the pure water in the water production tank circulate through the concentration chamber A and the concentration chamber B of the electrodialysis unit by C pump and D pump, and makes the electrode water in the electrode water tank circulate through the electrode chamber of the electrodialysis unit by E pump; during the running of the electrodialysis unit, the salt concentration of the desalination chamber A and the desalination chamber B gradually decreases, the salt concentration of the concentration chamber A and the concentration chamber B gradually increases, and the pH of the raw water in the electrode chamber gradually increases; during the running, the feed and discharge mode is adopted, valve B is connected to the outlet of the desalination chamber A, and by controlling the valve opening degree, part of the water discharged from the desalination chamber A is circulated in the water inlet pipeline 1, and the other part is discharged to the water production tank; the outlets of the desalination chamber B, the concentration chamber A and the concentration chamber B are connected to valves C, D and E, and by controlling the valve opening degree, part of the water discharged is circulated in the pipeline 2, the pipeline 3 and the pipeline 4, and the other part is discharged.

[0023] At the same time of sending the feed liquid into each compartment of the electrodialysis unit, valve A2 is opened to make the water in the raw water tank pass through the water pump F to make the salt-containing raw water pass through the chelating resin tank, and the raw water in the raw water tank is subjected to hardness removal after passing through the chelating resin; after the water quality meets the set requirements, the salt water for removing hardness in the chelating resin tank flows through the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialysis unit through the water pipeline and the water pumps G, H and I, and the electrode water in the electrode water tank flows through the electrode chamber of the bipolar membrane electrodialysis unit by E pump; during the running of the bipolar membrane electrodialysis unit, the acidity in the acid chamber gradually increases, the alkalinity in the alkali chamber gradually increases, and the concentration in the salt chamber gradually decreases; during the running, the feed and discharge mode is adopted, valves F, G and H are connected to the outlets of the acid chamber, the alkali chamber and the salt chamber, and by controlling the valve opening degree, part of the water discharged is circulated in the pipeline 5, the pipeline 6 and the pipeline 7, and the other part is discharged.

[0024] During the running of the integrated brackish water desalination device, if the pH of the raw water in the electrode chamber increases and exceeds the set value, valve I is opened to adjust the pH of the electrode chamber with the acid liquid in the acid chamber so that the pH is reduced to the set range; if the hardness removal of the chelating resin tank is slow or the hardness of the water no longer decreases, it indicates that the resin is saturated or tends to be saturated, and the resin column of the chelating resin tank is regenerated by alternately flushing with acid liquid, salt water, alkali liquid and salt water; the alkali chamber of the bipolar membrane electrodialysis unit is cleaned with the acid liquid of the bipolar membrane electrodialysis unit.

[0025] Another object of the present application is to provide a receiving user input program storage medium, the stored computer program causes the electronic device to execute the integrated brackish water desalination device.

[0026] Another object of the present application is to provide a computer device, the computer device comprises a memory and a processor, the memory stores a computer program, the computer program is executed by the processor, so that the processor executes the integrated brackish water desalination device.

[0027] Another object of the present application is to provide a computer readable storage medium, storing a computer program, the computer program is executed by the processor, so that the processor executes the steps of the integrated brackish water desalination device control method.

[0028] Another object of the present application is to provide an information data processing terminal, the information data processing terminal is installed on the electronic device to provide a user input interface to implement the steps of the integrated brackish water desalination device control method.

[0029] First, in combination with all the above technical solutions, the present application has the advantages and positive effects: in view of the technical problems existing in the prior art and the difficulty in solving the problem, combined with the technical solutions to be protected by the present application and the results and data in the research and development process, the technical problems solved by the present application are analyzed in detail and deeply, and some creative technical effects brought by the problem solving are described as follows:

[0030] The integrated brackish water desalination device provided by the present application comprises a pretreatment unit, a displacement electrodialysis unit, a bipolar membrane electrodialysis unit and a chelating resin tank. 2+ , Mg 2+ , SO4 2- , CO3 2- and other anions and cations are enriched in the concentration chamber and form a precipitate, block the flow channel of the concentration chamber, and form a scale layer on the membrane surface, affecting the treatment performance and service life of the membrane stack. The desalination chamber A of the displacement electrodialysis unit is connected to the pretreated raw water, and the desalination chamber B is connected to the configured sodium chloride solution; under the action of the electric field, the anions migrate to the positive electrode, and the cations migrate to the negative electrode. The anions (Cl - , SO4 2- , CO3 2- ) in the desalination chamber A and the cations (Na + ) in the desalination chamber B are migrated into the concentration chamber A, and the cations (Na + , K + , Ca 2+ , Mg 2+ ) in the desalination chamber A and the anions (Cl- ), the cations and anions which are easy to form scale in raw water migrate to different concentration chambers respectively, thereby effectively avoiding scale formation.

[0031] The bipolar membrane electrodialysis unit in the application can realize on-line production of acid and alkali, the produced acid can be used to adjust the pH value of the electrode solution to prevent scale formation in the electrode chamber, and can also be used to clean the alkali chamber of the bipolar membrane electrodialysis unit. If the resin tends to be saturated after the chelating resin tank is operated for a period of time, the acid and alkali produced by the bipolar membrane electrodialysis unit and the brine can be used to regenerate the resin alternately. In addition, the chelating resin tank in the application provides brine for the bipolar membrane electrodialysis unit, so that scale formation in the bipolar membrane electrodialysis unit is avoided.

[0032] There are various operation modes of electrodialysis. The "once through process" refers to continuous production of water to meet water quality standards by electrodialysis, which is often achieved by extending the process length through series connection of multiple devices or construction of multiple sections in a single device. The "batch process" refers to batch-wise desalination of water by electrodialysis, so that the intermittent batch water meets the water quality requirements. The "feed-and-bleed process" refers to the outlet of the water produced by electrodialysis being divided into two routes, one of which is continuously discharged for use at a water use point, and the other of which is returned to the electrodialyzer to mix with the feed water for continuous desalination. The "once through process" can realize continuous water production, but relies on series connection of devices or multiple section design in a device, and the water flow resistance is large, which is not suitable for high raw water salinity occasions. The "batch process" can only batch discharge the produced water, and multiple solution barrels are required to realize circulation of the dilute water and the concentrated water. The "feed-and-bleed process" can also realize continuous water production, and multiple solution barrels are required to realize circulation of the dilute water and the concentrated water. As shown in FIG. 1, to save the occupied space, the displacement electrodialysis unit and the bipolar membrane electrodialysis unit in the application are designed to have the "feed-and-bleed process" operation mode, i.e., the circulating back water is not returned to the solution barrel, but is returned to the water inlet end of the corresponding water pump, and the solution is partially circulated in the device, which saves the solution barrel and the liquid level meter required to be equipped in the solution barrel, and simplifies the control system of the device. Figures 2-3

[0033] ​Second, the displacement electrodialysis unit of the present application effectively avoids the precipitation of a large amount of calcium and magnesium ions in the concentrated chamber; the bipolar membrane electrodialysis unit can produce acid and alkali, the produced acid can be used to adjust the pH value of the electrode solution to prevent the scaling of the electrode chamber, the produced acid, alkali and salt water can be used to regenerate the resin, and the dehardened salt water provided by the chelating resin tank can be supplied to the bipolar membrane electrodialysis unit, so that the scaling of the bipolar membrane electrodialysis unit is avoided, and in addition, the alkali chamber of the bipolar membrane electrodialysis unit can also be cleaned with acid solution. The entire system runs without the need for additional acid and other reagents, breaking through the technical bottleneck of the development of electrodialysis method for brackish water desalination. In addition, the system adopts an internal partial circulation type desalination mode during operation, which not only saves the occupied space, makes the operation simple and the system stable, but also saves the cost.

[0034] Third, the creativity of the present application as the evidence of the claim is also reflected in the following important aspects:

[0035] (1) The expected income and commercial value of the technical scheme of the present application after transformation are: the distribution of brackish water in China is wide. In the arid inland areas of Northwest China, due to the scarcity of precipitation and strong evaporation, the water resources are naturally scarce, and the underground water as the main water supply is brackish water with poor quality. In Shandong, the distribution area of brackish water reaches 109,000 square kilometers, mainly distributed in the northwest of Shandong and the "Three North" area of Weifang City; due to the influence of groundwater runoff conditions and ancient sedimentary environment, various types of salt water are formed in the inland and coastal areas of the Yellow River floodplain and coastal plain areas of Shandong. The technical scheme of the present application can realize brackish water desalination, and has broad market prospects.

[0036] (2) The present application adopts a 4-compartment displacement electrodialysis structure instead of a traditional 2-compartment ordinary electrodialysis, and introduces sodium chloride solution, so as to overcome the scaling problem of concentrated water when ordinary electrodialysis is used to treat brackish water, and improve the water production rate; chelating resin and bipolar membrane electrodialysis unit are used to realize online production of acid and alkali, adjust the pH value of the electrodialysis electrode solution to overcome the scaling problem of the electrode chamber, and the produced acid and alkali are used for resin regeneration and cleaning of the bipolar membrane electrodialysis unit; the design of internal partial circulation type desalination makes the equipment structure compact and easy to control. The technical scheme of the present application realizes long-term stable operation of electrodialysis brackish water desalination, and fills the technical gap in the industry.

[0037] (3) The technical scheme of the present application solves the problems of scaling of concentrated water and scaling of electrode water in the electrodialysis brackish water desalination system through the coupling of multiple treatment units, so that the system can be operated stably for a long time; the technical scheme improves the water yield, the system structure is compact, the occupied area is small, and the system is easy to control. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings, which are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure;

[0039] Figure 1 is a schematic diagram of the structure principle of the integrated brackish water desalination device provided by the embodiment of the present application;

[0040] Figure 2 is a schematic diagram of the concentration chamber of the ordinary electrodialysis which is easy to form scale;

[0041] Figure 3 is a schematic diagram of the concentration chamber of the displacement electrodialysis which does not form scale. DETAILED DESCRIPTION

[0042] In order to make the above objectives, characteristics and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0043] Embodiment 1, as shown in the present application, the integrated brackish water desalination device provided by the embodiment of the present application includes a pretreatment unit, a displacement reaction electrodialysis unit, a bipolar membrane electrodialysis unit and a chelating resin tank. Figure 1 Among them, the displacement electrodialysis unit contains the inlet of the dilution chamber A, the dilution chamber B, the concentration chamber A, the concentration chamber B and the two polar chambers respectively through the A pump, the B pump, the C pump, the D pump and the E pump respectively with the raw water tank, the sodium chloride water tank, the water production tank and the polar water tank, the outlet of the dilution chamber A, the dilution chamber B, the concentration chamber A, the concentration chamber B and the water inlet pipeline 1, the pipeline 2, the pipeline 3 and the pipeline 4 are communicated through the valve respectively, the dilution chamber A outlet and the water production tank are communicated, the dilution chamber B, the concentration chamber A, the concentration chamber B outlet is provided with a liquid discharge valve, and the polar chamber outlet is communicated with the polar water tank;

[0044] The inlet of the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialysis unit and the inlet of the polar chamber are respectively communicated with the outlet of the chelating resin tank and the polar water tank through the G pump, the H pump, the I pump and the E pump, and the outlet of the acid chamber, the alkali chamber and the salt chamber is communicated with the water inlet pipeline 5, the pipeline 6 and the pipeline 7, wherein the acid chamber outlet is communicated with the polar water tank, the acid chamber, the alkali chamber and the salt chamber outlet is provided with a liquid discharge valve, and the polar chamber outlet is communicated with the polar water tank;

[0045] The inlet of the chelating resin tank is communicated with the raw water tank through the F pump and the water inlet pipeline 8, and the outlet is communicated with the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialysis through the G pump, the H pump and the I pump.

[0046]

[0047] Figure 1 ​Figure 1 is a schematic diagram of the structural principle of the application, the displacement electrodialysis unit comprises a plurality of membrane groups, only one group is indicated in the figure; the bipolar membrane electrodialysis unit comprises a plurality of membrane groups, only one group is indicated in the figure.

[0048] In the steady state operation of the integrated brackish water desalination device, the desalination chambers A and B and the concentration chambers A and B all operate in the "in-device partial circulation type desalination" mode; the raw water is sent into the desalination chamber A through the water inlet pipeline 1 by the A pump, the valve B is partially opened, a part of the water outlet of the desalination chamber A is circulated in the water inlet pipeline 1, and the other part is discharged into the product water tank; the sodium chloride solution is sent into the desalination chamber B through the water inlet pipeline 2 by the B pump, the valve C is partially opened, a part of the water outlet of the desalination chamber B is circulated in the water inlet pipeline 2, and the other part is discharged; the pure water is sent into the concentration chamber A through the water inlet pipeline 3 by the C pump, the valve D is partially opened, a part of the water outlet of the concentration chamber A is circulated in the water inlet pipeline 3, and the other part is discharged; the pure water is sent into the concentration chamber B through the water inlet pipeline 4 by the D pump, the valve E is partially opened, a part of the water outlet of the concentration chamber B is circulated in the water inlet pipeline 4, and the other part is discharged.

[0049] In the steady state operation of the integrated brackish water desalination device, the acid chamber, the alkali chamber and the salt chamber all operate in the "in-device partial circulation type desalination" mode; the hard salt water is sent into the acid chamber through the water inlet pipeline 5 by the G pump, the valve H is partially opened, a part of the water outlet of the acid chamber is circulated in the water inlet pipeline 5, and the other part is discharged; the hard salt water is sent into the alkali chamber through the water inlet pipeline 6 by the H pump, the valve G is partially opened, a part of the water outlet of the alkali chamber is circulated in the water inlet pipeline 6, and the other part is discharged; the hard salt water is sent into the salt chamber through the water inlet pipeline 7 by the I pump, the valve F is partially opened, a part of the water outlet of the salt chamber is circulated in the water inlet pipeline 7, and the other part is discharged.

[0050] The product water tank is connected with the acid chamber, the alkali chamber and the salt chamber through the water inlet pipelines 5, 6 and 7 respectively, and the water outlet of the product water tank is connected with the water inlet pipeline 8 through the valve J.

[0051] The integrated brackish water desalination device provided by the embodiment of the application further comprises a pretreatment unit, and the outlet of the pretreatment unit is connected with the raw water tank through the water inlet pipeline.

[0052] The pretreatment unit provided by the embodiment of the application is one or more than two combinations of the following multiple sub-units: precision filtration, microfiltration, ultrafiltration, medicament addition and disinfection and sterilization.

[0053] The chelating resin tank can be regenerated by alternately washing the resin column of the chelating resin tank with water in the acid chamber, the alkali chamber and the salt chamber of the bipolar membrane electrodialysis unit; and the alkali chamber of the bipolar membrane electrodialysis unit can be cleaned with the acid liquid produced by the bipolar membrane electrodialysis unit.

[0054] The pretreatment unit, the displacement electrodialysis unit, the bipolar membrane electrodialysis unit and the chelating resin tank used in the integrated brackish water desalination device provided by the embodiments of the present application are all commercially available products. For example, the pretreatment device, the displacement electrodialysis unit and the bipolar membrane electrodialysis unit produced by Shandong Tianwei Membrane Technology Co., Ltd. and the chelating resin tank produced by Jiangsu Suqing Water Treatment Engineering Group can be used.

[0055] There are various operation modes of electrodialysis. The "once through process" refers to continuous production of fresh water by electrodialysis to reach the water quality standard, which is often achieved by extending the process length through series connection of multiple devices or construction of multiple sections in a single device. The "batch process" refers to batch-wise desalination of fresh water by electrodialysis to reach the water quality requirement. The "feed-and-bleed process" refers to that the outlet of the electrodialysis fresh water is divided into two routes, one of which is continuously discharged for use by the water user, and the other of which is returned to the electrodialysis device to continue desalination with the feed water. The "once through process" can achieve continuous water production, but it depends on the series connection of devices or the multi-section design in a device, and the water flow resistance is large, which is not suitable for high raw water salinity occasions. The "batch process" can only batch discharge the produced water, and multiple solution barrels are required to achieve the circulation of fresh water and concentrated water. The "feed-and-bleed process" can also achieve continuous water production, and multiple solution barrels are required to achieve the circulation of fresh water and concentrated water. As shown in FIG. 1, in order to save the occupied space, the displacement electrodialysis unit and the bipolar membrane electrodialysis unit provided by the embodiments of the present application are designed to have the "feed-and-bleed process" operation mode, i.e., the circulating back water is not returned to the solution barrel, but is returned to the water inlet end of the corresponding water pump, and the solution is partially circulated in the device, which saves the solution barrel and the liquid level meter required by the solution barrel, and simplifies the control system of the device. Figures 2-3

[0056] The displacement electrodialysis unit in the present application can effectively prevent the precipitation of Ca 2+ , Mg 2+ , SO4 2- , HCO3 - (CO3 2- ​) etc. cation and anion are enriched to form precipitate, which blocks the flow channel of the concentration chamber. The bipolar membrane electrodialysis unit in the present application can realize online production of acid and alkali, the produced acid can be used to adjust the pH value of the electrode solution to prevent the electrode chamber from scaling, and can also be used to clean the alkali chamber of the bipolar membrane electrodialysis unit; if the chelating resin tank tends to be saturated after a period of operation, the acid, alkali and brine produced by the bipolar membrane electrodialysis unit can be used to regenerate the resin alternately. The chelating resin tank provides the bipolar membrane electrodialysis unit with desalted brine, so that the bipolar membrane electrodialysis unit will not scale. The whole system operates without additional acid and other reagents, which solves the technical bottleneck of the development of electrodialysis method for brackish water desalination. In addition, the operation mode of the present application adopts an internal partial circulation type desalination mode, which not only saves the occupied space, makes the operation simple and the system stable, but also saves the cost.

[0057] In embodiment 2, the control method of the integrated brackish water desalination device provided by the present application comprises the following steps:

[0058] The salt-containing raw water is sent to the raw water tank after being treated by the pretreatment unit, and the supply of raw water is stopped when the set liquid level is reached. A certain volume of 20% sodium chloride solution is configured in the sodium chloride tank, a certain volume of pure water is supplied to the product water tank, and the valves A1 and A2 are opened, so that part of the raw water in the raw water tank flows into the electrode water tank through the water supply pipeline 8, and the other part of the raw water passes through the chelating resin tank for hardness removal through the water pump F. When the water quality and liquid level of the outlet water meet the set requirements, the valves A1 and A2 and the water pump F are closed. At the same time, the A pump, the B pump, the C pump, the D pump, the E pump, the G pump, the H pump and the I pump are started to make the displacement electrodialysis unit and the bipolar membrane electrodialysis unit operate, that is, the raw water in the raw water tank is circulated through the desalination chamber A through the A pump at the same time, the sodium chloride solution in the sodium chloride tank is circulated through the desalination chamber B through the B pump, the pure water in the product water tank is circulated through the concentration chamber A and the concentration chamber B through the C pump and the D pump, the desalted brine in the chelating resin tank is circulated through the acid chamber through the G pump, through the alkali chamber through the H pump, and through the salt chamber through the I pump, and the electrode water in the electrode water tank is circulated through the electrode chamber of the displacement electrodialysis unit and the bipolar membrane electrodialysis unit through the E pump. During the operation, the feed and discharge mode is adopted, that is, the outlet communication valves B, C, D, E, F, G and H of the desalination chamber A, the desalination chamber B, the concentration chamber A, the concentration chamber B, the acid chamber, the alkali chamber and the salt chamber are connected, and part of the outlet water of the desalination chamber A is circulated through the water inlet pipeline 1 for operation, and the other part is discharged to the product water tank. Part of the outlet water of the desalination chamber B, the concentration chamber B, the acid chamber, the alkali chamber and the salt chamber is circulated through the water inlet pipeline 2, the pipeline 3, the pipeline 4, the pipeline 5, the pipeline 6 and the pipeline 7 for operation, and the other part is discharged.

[0059] During operation, if the pH value of the raw water in the electrode chamber exceeds the set value, the valve I is opened to adjust the pH value of the electrode chamber with the acid liquid in the acid chamber, so that the pH value is reduced to the set range; if the hardness removal of the chelating resin tank is slow or the hardness of the water does not decrease any more, it indicates that the resin is saturated or tends to be saturated, and then the resin column of the chelating resin tank is regenerated by using the acid liquid, the brine, the alkali liquid and the brine alternately, and the alkali chamber of the bipolar membrane electrodialysis unit is cleaned by using the acid liquid of the bipolar membrane electrodialysis unit.

[0060] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0061] The information interaction and execution process between the above devices / units are based on the same concept as the method embodiments of the application, and the specific functions and brought technical effects can be referred to the method embodiments part, which will not be repeated here.

[0062] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is taken as an example, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software. In addition, the specific name of each functional unit and module is only for easy distinction, and does not limit the protection scope of the application. The specific working process of the unit and module in the system can be referred to the corresponding process in the foregoing method embodiments.

[0063] According to the embodiments of the present application, the application further provides a computer device, which comprises at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, wherein the processor implements the steps in any of the above method embodiments when executing the computer program.

[0064] The embodiment of the application further provides a computer readable storage medium, which stores a computer program, wherein the computer program is executable by a processor to implement the steps in any of the above method embodiments.

[0065] The embodiment of the present application further provides an information data processing terminal, which is used to provide a user input interface to implement the steps in the above method embodiments when executed on an electronic device, and is not limited to a mobile phone, a computer or a switch.

[0066] The embodiment of the present application further provides a server, which is used to provide a user input interface to implement the steps in the above method embodiments when executed on an electronic device.

[0067] The embodiment of the present application further provides a computer program product, which, when executed on an electronic device, enables the electronic device to implement the steps in the above method embodiments.

[0068] The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the processes in the above embodiments by a computer program to instruct related hardware, and the computer program can be stored in a computer-readable storage medium. The computer program, when executed by a processor, can implement the steps of the above method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, an executable file or some intermediate form. The computer-readable medium at least includes any entity or device capable of carrying the computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal and a software distribution medium. For example, a U disk, a mobile hard disk, a magnetic disk or an optical disk.

[0069] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0070] To further prove the positive effects of the above embodiments, the present application performs the following experiments based on the above technical solutions.

[0071] The TDS of a certain brackish water is 10 g / L, and a displacement electrodialysis equipment (single membrane area 0.6 m 2, the device contains 100 membrane pairs. The raw water filtered by the microfiltration membrane enters the desalination chamber A, the desalination chamber B contains 20% sodium chloride solution, and pure water enters the concentration chambers A and B. The average operating current is 100 A. When the concentration of the water discharged from the desalination chamber A drops to 0.05%, the produced water is qualified. When the concentration of the desalination chamber B drops to 1% and the concentrations of the concentration chambers A and B reach 20%, they are discharged. The electrodialysis device produces 3.2 m of fresh water per hour. 3 , about 80 L of water needs to be replenished to the desalination chamber B, the concentration chambers A and B per hour respectively, and the net water production of the device is about 3 m 3 / h. The system is equipped with a small bipolar membrane electrodialysis unit, model TWEDBM-2-30 (the area of a single membrane sheet is 0.02 m 2 , the device contains 30 membrane pairs), and the amount of acid and alkali produced per hour is about 3.7 mol. The produced acid and alkali are sufficient to adjust the pH value of the electrode solution, regenerate the resin and clean the bipolar membrane electrodialysis unit. This device can operate stably for a long time.

[0072] As described above, it is only a preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement and improvement made within the spirit and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. An integrated brackish water desalination device, characterized in that, The device includes a pretreatment unit, a displacement electrodialysis unit, a bipolar membrane electrodialysis unit, and a chelating resin tank; The pretreatment unit is a combination of one or more of the following sub-units: precision filtration, microfiltration, ultrafiltration, chemical addition, and disinfection. The outlet of the pretreatment unit is connected to the raw water tank through a water supply pipeline. The inlets of desalination chambers A and B and the two electrode chambers of the displacement electrodialysis unit are connected to the raw water tank, sodium chloride tank and electrode water tank respectively through pumps A, B and E. The concentration chambers A and B of the displacement electrodialysis unit are connected to the product water tank respectively through pumps C and D. The inlet pipe 1 is between pump A and the raw water tank, the pipe 2 is between pump B and the sodium chloride tank, the pipe 3 is between pump C and the product water tank, and the pipe 4 is between pump D and the product water tank. The outlets of desalination chambers A, B, A and B and concentration chambers A and B are connected to inlet pipes 1, 2, 3 and 4 respectively through valves. The outlet of desalination chamber A is connected to the product water tank. Drain valves are installed at the outlets of desalination chambers B, A and B and the electrode chamber outlet is connected to the electrode water tank. The inlets of the acid, alkali, and salt chambers of the bipolar membrane electrodialysis unit are connected to the outlet of the chelating resin tank via pumps G, H, and I, respectively. The inlet of the electrode chamber of the bipolar membrane electrodialysis unit is connected to the electrode water tank via pump E. Pump G is connected to the chelating resin tank via inlet pipe 5, pump H is connected to the chelating resin tank via pipe 6, and pump E is connected to the chelating resin tank via pipe 7. The outlets of the acid, alkali, and salt chambers are connected to inlet pipes 5, 6, and 7, respectively. The outlet of the acid chamber is connected to the electrode water tank. Drain valves are installed at the outlets of the acid, alkali, and salt chambers. The outlet of the electrode chamber is connected to the electrode water tank. The inlet of the chelating resin tank is connected to the raw water tank via pump F and inlet pipe 8; the desalination chambers A, B, A, and B of the displacement electrodialysis unit all operate in a partially circulating desalination mode within the equipment; inlet pipe 1 sends raw water into desalination chamber A via pump A, valve B is partially opened, part of the water effluent from desalination chamber A returns to inlet pipe 1 for circulation, and the other part is discharged into the product water tank; inlet pipe 2 sends sodium chloride solution into desalination chamber B via pump B, valve C is partially opened, part of the water effluent from desalination chamber B returns to inlet pipe 2 for circulation, and the other part is discharged externally; The inlet pipe 3 sends pure water into the concentration chamber A through pump C. Valve D is partially opened, and part of the water from the concentration chamber A is circulated through the inlet pipe 3, while the other part is discharged. The inlet pipe 4 sends pure water into the concentration chamber B through pump D. Valve E is partially opened, and part of the water from the concentration chamber B returns to the inlet pipe 4 for circulation, while the other part is discharged. The acid, alkali, and salt chambers of the bipolar membrane electrodialysis unit all operate in a partially circulating desalination mode within the equipment. Inlet pipe 5 sends de-hardened brine into the acid chamber via pump G, with valve H partially open. Part of the acid chamber effluent returns to inlet pipe 5 for circulation, while the other part is discharged. Inlet pipe 6 sends de-hardened brine into the alkali chamber via pump H, with valve G partially open. Part of the alkali chamber effluent returns to inlet pipe 6 for circulation, while the other part is discharged. Inlet pipe 7 sends de-hardened brine into the salt chamber via pump I, with valve F partially open. Part of the salt chamber effluent returns to inlet pipe 7 for circulation, while the other part is discharged.

2. The integrated brackish water desalination device according to claim 1, characterized in that, The raw water tank directs water into the electrode water tank and chelating resin tank through valves A1 and A2, respectively.

3. The integrated brackish water desalination device according to claim 1, characterized in that, The acid solution produced by the bipolar membrane electrodialysis unit is discharged into the electrode water tank through valve I to adjust the pH value of the electrode solution.

4. The integrated brackish water desalination device according to claim 1, characterized in that, The resin column of the chelating resin tank is regenerated by alternately washing it with acid, brine, alkali and brine from the bipolar membrane electrodialysis unit.

5. The integrated brackish water desalination device according to claim 1, characterized in that, The alkali chamber of the bipolar membrane electrodialysis unit is cleaned with acid from the bipolar membrane electrodialysis unit.

6. A control method for an integrated brackish water desalination device, characterized in that, This method utilizes the integrated brackish water desalination device described in any one of claims 1-5, and the method includes: The integrated brackish water desalination unit treats saline raw water through a pretreatment unit and then sends it to the raw water tank. Once the set liquid level is reached, the supply of raw water stops. A certain volume of 15% sodium chloride solution is placed in the sodium chloride tank, and a certain volume of pure water is supplied to the product water tank. Valve A1 is opened, allowing some water from the raw water tank to flow into the electrode water tank. Pumps A, B, C, D, and E are started to operate the displacement electrodialysis unit. Simultaneously, the raw water in the raw water tank circulates through the desalination chamber A of the electrodialysis unit via pump A, the sodium chloride solution in the sodium chloride tank circulates through the desalination chamber B of the electrodialysis unit via pump B, and the pure water in the product water tank circulates through the concentration chambers A and B of the electrodialysis unit via pumps C and D, thus facilitating the desalination of the electrode water. The electrode water in the tank circulates through the electrode chambers of the electrodialysis unit via pump E. During the operation of the electrodialysis unit, the salt concentration in desalination chambers A and B gradually decreases, while the salt concentration in concentration chambers A and B gradually increases, and the pH of the raw water in the electrode chambers gradually increases. During operation, a simultaneous feeding and discharging mode is adopted. Valve B is connected at the outlet of desalination chamber A. By controlling the valve opening, part of the water effluent from desalination chamber A returns to the inlet pipe 1 for circulation, while the other part is discharged into the product water tank. Valves C, D, and E are connected at the outlets of desalination chamber B, concentration chamber A, and concentration chamber B. By controlling the valve opening, part of the effluent flows through the conveying pipes into pipes 2, 3, and 4 for circulation, while the other part is discharged externally. While the feed solution is being fed into each compartment of the electrodialysis unit, valve A2 is opened to allow water in the raw water tank to pass through the chelating resin tank via pump F. The raw water in the raw water tank undergoes hardness removal after passing through the chelating resin. Once the effluent quality meets the set requirements, the de-hardened brine in the chelating resin tank flows through the water supply pipeline and pumps G, H, and I through the acid, alkali, and salt compartments of the bipolar membrane electrodialysis unit. The electrode water in the electrode tank flows through the electrode compartments of the bipolar membrane electrodialysis unit via pump E. During the operation of the bipolar membrane electrodialysis unit, the acidity in the acid compartment gradually increases, the alkalinity in the alkali compartment gradually increases, and the concentration in the salt compartment gradually decreases. A simultaneous feeding and discharging mode is adopted during operation. Valves F, G, and H are connected at the outlets of the acid, alkali, and salt compartments. By controlling the valve opening, part of the effluent is circulated through pipelines 5, 6, and 7, while the other part is discharged. During the operation of the integrated brackish water desalination unit, if the pH value of the raw water in the electrode chamber rises above the set value, valve I is opened to adjust the pH value of the electrode chamber with acid in the acid chamber, so that the pH value is reduced to the set range. If the hardness removal in the chelating resin tank is slow or the hardness of the water no longer decreases, it indicates that the resin replacement is saturated or tending to be saturated. In this case, acid, brine, alkali and brine are used to alternately flush the resin column of the chelating resin tank to regenerate the resin. The alkali chamber of the bipolar membrane electrodialysis unit is cleaned with acid from the bipolar membrane electrodialysis unit.

7. A user input program storage medium, wherein the stored computer program causes an electronic device to execute the integrated brackish water desalination apparatus as described in any one of claims 1-5.

8. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the integrated brackish water desalination device as described in any one of claims 1-5.

9. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the integrated brackish water desalination device control method as described in claim 6.

10. An information data processing terminal, characterized in that, The information data processing terminal is installed on the electronic device to provide a user input interface for implementing the steps of the integrated brackish water desalination device control method as described in claim 6.

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