A multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater

Abstract

The invention discloses a multi-membrane stacked electrolysis device for producing acid and alkali by using high-salt organic wastewater, which relates to the technical field of high-salt organic wastewater treatment, including a stack system, a DC power supply system and a liquid circulation system, wherein the stack system includes an anode clamping plate and a cathode clamping plate, wherein an anode plate is arranged at one end of the anode clamping plate facing the cathode clamping plate, and a cathode plate is arranged at one end of the cathode clamping plate facing the anode plate, and a plurality of circulation stack units are arranged between the cathode plate and the anode plate; the circulation stack unit includes a wastewater chamber partition, a cation exchange membrane, an alkali chamber partition, a bipolar membrane, an acid chamber partition, an anion exchange membrane, a wastewater chamber partition and a flexible bipolar electrode plate. Thus, under the action of an external electric field, salt cations and salt anions in the wastewater migrate in a directional manner, and enter the alkali chamber and the acid chamber respectively through the anion and cation exchange membrane, so as to achieve the purpose of recovering salt. At the same time, the salt in the wastewater is removed and the organic matter is degraded, thereby improving the efficiency of subsequent biochemical treatment of wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of high-salt organic wastewater treatment, and in particular to a multi-membrane stacked electrolysis device that utilizes high-salt organic wastewater to generate acid and alkali. Background Art

[0002] In the field of industrial wastewater, environmental pollution caused by salt-containing organic wastewater is particularly prominent, and there are problems such as large wastewater volume, complex composition, and difficulty in treatment. Since the organic components in this type of wastewater are complex and the organic matter contained therein has no recycling value, biochemical treatment is still one of the most economical and effective means. For conventional biochemical treatment, the high concentration of salt in this type of wastewater will inhibit the activity of microorganisms and reduce the efficiency of biochemical treatment. In severe cases, it will cause microbial dehydration and death, making biochemical operation difficult. In industry, multi-effect evaporation and salt crystallization methods are usually used to remove salt from high-salt, difficult-to-degrade organic wastewater, but the operating costs are high, and the solid salt products are usually hazardous wastes, which increases the difficulty of subsequent treatment.

[0003] For high-salinity and difficult-to-degrade organic wastewater, high-concentration salt has recycling value. The traditional recycling technology is generally bipolar membrane electrodialysis, but the traditional bipolar membrane electrodialysis has low current efficiency and poor biochemical effect of wastewater. Summary of the invention

[0004] In view of the above defects, the purpose of the present invention is to provide a multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater, aiming to solve the problems of low current efficiency and poor biochemical effect of wastewater in the prior art bipolar membrane electrodialysis.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater, comprising a stack system, a DC power supply system and a liquid circulation system, wherein the DC power supply system is electrically connected to the stack system, the stack system is connected to a pipeline of the liquid circulation system, the stack system comprises an anode clamping plate and a cathode clamping plate, an anode plate is arranged at one end of the anode clamping plate facing the cathode clamping plate, a cathode plate is arranged at one end of the cathode clamping plate facing the cathode, and a plurality of circulation stack units are arranged between the cathode plates;

[0007] The circulation stack unit is provided with a wastewater chamber partition, a cation exchange membrane, an alkali chamber partition, a bipolar membrane, an acid chamber partition, an anion exchange membrane, a wastewater chamber partition and a flexible bipolar electrode plate in sequence along the direction from the anode plate to the cathode plate. A wastewater anode chamber is provided between the anode plate and the cation exchange membrane, an alkali solution compartment is provided between the cation exchange membrane and the bipolar membrane, an acid solution compartment is provided between the bipolar membrane and the anion exchange membrane, and a wastewater cathode chamber is provided between the anion exchange membrane and the flexible bipolar electrode plate.

[0008] Wherein, the liquid circulation system includes a wastewater circulation system, an alkali circulation system and an acid circulation system, the wastewater circulation system includes a wastewater storage tank and a wastewater circulation pump, the wastewater storage tank is connected to the wastewater circulation pump pipeline, a wastewater pipeline is arranged between the wastewater anode chamber, the wastewater cathode chamber and the wastewater circulation pump, and the wastewater anode chamber and the wastewater cathode chamber are connected to the wastewater storage tank pipeline; the alkali circulation system includes an alkali storage tank and an alkali circulation pump, the alkali storage tank is connected to the alkali circulation pump pipeline, an alkali pipeline is arranged between the alkali circulation pump and the alkali compartment, and the alkali compartment is connected to the alkali storage tank by pipeline; the acid circulation system includes an acid storage tank and an acid circulation pump, the acid storage tank is connected to the acid circulation pump by pipeline, an acid pipeline is arranged between the acid circulation pump and the acid compartment, and the acid compartment is connected to the acid storage tank by pipeline.

[0009] Wherein, an alkali solution inlet hole, a wastewater inlet hole and an acid solution inlet hole are sequentially arranged at the bottom of the anode plate.

[0010] Wherein, an acid outlet hole, a wastewater outlet hole and an alkali outlet hole are arranged on the top of the cathode plate.

[0011] Among them, a first water distribution hole is arranged at the bottom of the alkali chamber partition, and a first water collection hole is arranged at the top of the alkali chamber partition; a second water distribution hole is arranged at the bottom of the wastewater chamber partition, and a second water collection hole is arranged at the top of the wastewater chamber partition; a third water distribution hole is arranged at the bottom of the acid chamber partition, and a third water collection hole is arranged at the top of the acid chamber partition, and the first water distribution hole, the second water distribution hole and the third water distribution hole are all provided with water distribution grooves.

[0012] Among them, the flexible double electrode plate includes a flexible electrode positive plate and a flexible electrode negative plate, an insulating layer is arranged between the flexible electrode positive plate and the flexible electrode negative plate, a fourth water collection hole is arranged on the top of the flexible double electrode plate, a fourth water distribution hole is arranged on the bottom of the flexible double electrode plate, and a water distribution trough is arranged on one side of the fourth water distribution hole.

[0013] Among them, the flexible electrode positive plates are all made of titanium coated with ruthenium, and the flexible electrode negative plates are made of stainless steel.

[0014] The DC power supply system is a constant current source, and the current density of the constant current source is 0 mA / cm 2 ~100mA / cm 2 .

[0015] Among them, the anode plate is made of titanium coated with ruthenium.

[0016] Wherein, the alkali chamber partition includes a support frame and a support wire mesh, the support frame is arranged around the alkali solution compartment, and the support wire mesh is located in the alkali solution compartment.

[0017] After adopting the above technical solution, the beneficial effects of the present invention are:

[0018] (1) The multi-membrane stacked electrolysis device for high-salinity organic wastewater can recycle salt resources and solve the problem of high-salinity organic wastewater treatment. Under the action of an external electric field, the salt cations and salt anions in the wastewater migrate in a directional manner and enter the alkaline chamber and acid chamber respectively through the anion and cation exchange membrane to achieve the purpose of salt recovery. At the same time, the salt in the wastewater is removed, improving the efficiency of subsequent wastewater biochemical treatment.

[0019] (2) High-salt organic wastewater directly enters the electrode compartment, and organic matter undergoes degradation reaction on the electrode surface, converting large molecular organic matter into small molecular organic matter, thereby improving the biodegradability of the wastewater.

[0020] (3) The stacking method of multi-unit stacking in the multi-membrane stacked electrolysis device for high-salinity organic wastewater can increase the wastewater treatment capacity of the system; the use of partitions to form a compartment structure can improve the electrochemical reaction efficiency of the substance; the use of flexible double electrodes in the middle part of the stack can reduce the possibility of liquid leakage in the device; this device configuration can improve the system current efficiency, reduce the system energy consumption, and save production costs.

[0021] (4) The plates and separators used in the multi-membrane stacked electrolysis device for high-salinity organic wastewater are equipped with three parallel groups of water distribution holes / water collection holes to ensure that the wastewater, acid solution, and alkaline solution in the stack system circulate independently, avoiding "cross-talk" between different solutions, thereby achieving the purpose of recovering high-purity acids and alkalis. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater;

[0023] Figure 2 The structure of the stack system;

[0024] Figure 3 Schematic diagram of the structure of the anode plate;

[0025] Figure 4 It is the structural diagram of the alkali solution inlet hole;

[0026] Figure 5 This is the structural diagram of the wastewater inlet hole;

[0027] Figure 6 This is the structural diagram of the acid inlet hole;

[0028] Figure 7 is the structural diagram of the cathode plate;

[0029] Figure 8 This is the structural diagram of the acid outlet hole;

[0030] Fig. 9 This is the structural diagram of the wastewater outlet;

[0031] Fig.10 This is the structural diagram of the alkali solution outlet;

[0032] Fig.11 It is a schematic diagram of the structure of the alkali chamber partition;

[0033] Fig.12 The schematic diagram of the structure of the wastewater chamber partition;

[0034] Fig.13 The schematic diagram of the structure of the acid chamber partition;

[0035] Fig.14 It is the structural diagram of the flexible electrode positive plate;

[0036] Fig.15 is a cross-sectional view of a flexible dual-electrode plate;

[0037] Fig.16 It is the structural diagram of the flexible electrode negative plate;

[0038] Fig.17 is a graph showing the change in MMTD content in the wastewater anode chamber in Example 1;

[0039] Fig.18 is a graph showing the change in MMTD content in the acid compartment in Example 1;

[0040] Fig.19 is a graph showing the change in MMTD content in the alkali solution compartment in Example 1;

[0041] Fig. 20 is a graph showing the change in potassium sulfate content in the wastewater anode chamber in Example 1;

[0042] Fig.21 is a graph showing the change in acid content in the acid solution compartment in Example 1;

[0043] Fig. 22 is a graph showing changes in alkali content in the alkali solution compartment in Example 1;

[0044] Fig.23 is a graph showing the change in MMTD content in the wastewater anode chamber in Example 2;

[0045] Fig.24 is a graph showing the change in MMTD content in the acid compartment in Example 2;

[0046] Fig.25 is a graph showing the change in MMTD content in the alkali solution compartment in Example 2;

[0047] Fig.26 is a graph showing the change in potassium sulfate content in the wastewater anode chamber in Example 2;

[0048] Fig. 27 is a graph showing changes in the acid content in the acid solution compartment in Example 2;

[0049] Fig.28 is a graph showing changes in alkali content in the alkali solution compartment in Example 2;

[0050] Fig.29 is a graph showing the change in MMTD content in the wastewater anode chamber in Example 3;

[0051] Fig.30 is a graph showing the change in MMTD content in the acid compartment in Example 3;

[0052] Fig.31 is a graph showing the change in MMTD content in the alkali solution compartment in Example 3;

[0053] Fig.32 is a graph showing the change in potassium sulfate content in the wastewater anode chamber in Example 3;

[0054] Fig.33 is a graph showing changes in the acid content in the acid solution compartment in Example 3;

[0055] Fig.34 This is a graph showing the change in alkali content in the alkali solution compartment in Example 3.

[0056] In the figure: 1-stack system, 2-DC power supply system, 3-liquid circulation system, 301-wastewater circulation system, 302-alkali circulation system, 303-acid circulation system, 4-wastewater storage tank, 5-wastewater circulation pump, 6-wastewater pipeline, 7-alkali storage tank, 8-alkali circulation pump, 9-alkali pipeline, 10-acid storage tank, 11-acid circulation pump, 12-acid pipeline, 13-anode clamping plate, 14-anode plate, 15-wastewater chamber partition, 151-support frame, 152-support wire mesh, 16-cation exchange membrane, 17-alkali chamber partition, 18-bipolar membrane, 19-acid chamber partition, 20-anion exchange membrane, 21-flexible double electrode plate, 22- Cathode plate, 23-cathode clamping plate, 241-wastewater anode chamber, 25-alkali solution compartment, 26-acid solution compartment, 242-wastewater cathode chamber, 27-anode input end, 28-alkali solution inlet hole, 29-wastewater inlet hole, 30-acid solution inlet hole, 31-cathode input end, 32-acid solution outlet hole, 33-wastewater outlet hole, 34-alkali solution outlet hole, 35-first water distribution hole, 36-first water collection hole, 37-second water distribution hole, 38-second water collection hole, 39-third water distribution hole, 40-third water collection hole, 41-flexible electrode cathode end, 42-fourth water distribution hole, 43-fourth water collection hole, 44-flexible electrode anode end, 45-flexible electrode positive plate, 46-flexible electrode negative plate. DETAILED DESCRIPTION

[0057] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0058] Example:

[0059] like Figure 1-16 As shown, a multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater comprises a stack system 1, a DC power supply system 2 and a liquid circulation system 3, wherein the DC power supply system 2 is electrically connected to the stack system 1, and the stack system 1 is connected to the liquid circulation system 3 by pipeline, and the stack system 1 comprises an anode clamping plate 13 and a cathode clamping plate 23, wherein an anode plate 14 is arranged at one end of the anode clamping plate 13 facing the cathode clamping plate 23, and a cathode plate 22 is arranged at one end of the cathode clamping plate 23 facing the anode plate 14, and a plurality of circulation stack units are arranged between the cathode plate 22 and the anode plate 14;

[0060] The circulation stack unit is provided with a wastewater chamber partition 15, a cation exchange membrane 16, an alkali chamber partition 17, a bipolar membrane 18, an acid chamber partition 19, an anion exchange membrane 20, a wastewater chamber partition 15 and a flexible bipolar electrode plate 21 in sequence along the direction from the anode plate 14 to the cathode plate 22. A wastewater anode chamber 241 is provided between the anode plate 14 and the cation exchange membrane 16, an alkali solution compartment 25 is provided between the cation exchange membrane 16 and the bipolar membrane 18, an acid solution compartment 26 is provided between the bipolar membrane 18 and the anion exchange membrane 20, and a wastewater cathode chamber 242 is provided between the anion exchange membrane 20 and the flexible bipolar electrode plate 21.

[0061] The working principle of this scheme is:

[0062] Wastewater anode chamber reaction: H2O-e − →•OH+H + (or OH − -e − →•OH, 2H2O→H2O2+2H + +2e − , H2O+O2→O3+2H + +2e − , 3H2O→O3+6H + +6e − );RH+•OH→R•+ H2O;

[0063] Wastewater cathode chamber reaction: 2H2O+4e − →2OH − +H2 (or O2+2H + +2e − →H2O2, H2O2+e − →•OH+OH − );

[0064] Total reaction in lye chamber: M m+ (Salt cation) + OH - (generated in bipolar membrane) → M(OH) m ;

[0065] Total reaction in the acid chamber: nH + (generated from bipolar membrane) + N n- (Salt anion) → H n N.

[0066] The liquid circulation system 3 includes a wastewater circulation system 301, an alkali liquid circulation system 302 and an acid liquid circulation system 303. The wastewater circulation system 301 includes a wastewater storage tank 4 and a wastewater circulation pump 5. The wastewater storage tank 4 is connected to the wastewater circulation pump 5 by a pipeline. A wastewater pipeline 6 is provided between the wastewater anode chamber 241, the wastewater cathode chamber 242 and the wastewater circulation pump 5. The wastewater anode chamber 241 and the wastewater cathode chamber 242 are connected to the wastewater storage tank 4 by a pipeline. The alkali liquid circulation system 302 includes an alkali liquid storage tank 7 The alkali liquid circulation pump 8 is connected to the alkali liquid storage tank 7 through a pipeline. An alkali liquid pipeline 9 is arranged between the alkali liquid circulation pump 8 and the alkali liquid compartment 25. The alkali liquid compartment 25 is connected to the alkali liquid storage tank 7 through a pipeline. The acid liquid circulation system 303 includes an acid liquid storage tank 10 and an acid liquid circulation pump 11. The acid liquid storage tank 10 is connected to the acid liquid circulation pump 11 through a pipeline. An acid liquid pipeline 12 is arranged between the acid liquid circulation pump 11 and the acid liquid compartment 26. The acid liquid compartment 26 is connected to the acid liquid storage tank 10 through a pipeline.

[0067] An alkali solution inlet 28, a wastewater inlet 29 and an acid solution inlet 30 are sequentially arranged at the bottom of the anode plate 14; the wastewater pipeline 6 is located between the wastewater inlet 29 and the wastewater circulation pump 5; the alkali solution pipeline 9 is located between the alkali solution inlet 28 and the alkali solution circulation pump 8; and the acid solution pipeline 12 is located between the acid solution inlet 30 and the acid solution circulation pump 11.

[0068] The top of the cathode plate 22 is provided with an acid outlet 32 ​​, a wastewater outlet 33 and an alkali outlet 34 .

[0069] A first water distribution hole 35 is provided at the bottom of the alkali chamber partition 17, and a first water collection hole 36 is provided at the top of the alkali chamber partition 17; a second water distribution hole 37 is provided at the bottom of the wastewater chamber partition 15, and a second water collection hole 38 is provided at the top of the wastewater chamber partition 15; a third water distribution hole 39 is provided at the bottom of the acid chamber partition 19, and a third water collection hole 40 is provided at the top of the acid chamber partition 19, and the first water distribution hole 35, the second water distribution hole 37 and the third water distribution hole 39 are all provided with water distribution grooves.

[0070] In this solution, the wastewater stored in the wastewater storage tank 4 reaches the wastewater inlet 29 at the bottom of the anode plate 14 through the wastewater pipe under the drive of the wastewater circulation pump 5, and then enters the stack system 1 through the wastewater inlet 29. Then the wastewater in the stack system 1 will be evenly distributed to the wastewater chamber through the second water distribution hole 37 at the bottom of the wastewater chamber partition 15. Similarly, the alkali stored in the alkali liquid storage tank 7 is sent to the alkali liquid inlet 28 by the alkali liquid circulation pump 8 through the alkali liquid pipeline 9, and then sent to the alkali liquid compartment 25 through the first water distribution hole 35; the acid stored in the acid liquid storage tank 10 is sent to the acid liquid inlet 30 by the acid liquid circulation pump 11 through the acid liquid pipeline 12, and then sent to the acid liquid compartment 26 through the second water distribution hole 37.

[0071] In order to facilitate the normal operation of the device, the positive pole of the DC power supply system 2 is respectively connected to the anode input terminal 27 of the anode plate 14 and the flexible electrode anode terminal 44 of the flexible dual-electrode plate 21, and the negative pole of the DC power supply system 2 is respectively connected to the cathode input terminal 31 of the cathode plate 22 and the flexible electrode cathode terminal 41 of the flexible dual-electrode plate 21.

[0072] The flexible double electrode plate 21 includes a flexible electrode positive plate 45 and a flexible electrode negative plate 46, an insulating layer is arranged between the flexible electrode positive plate 45 and the flexible electrode negative plate 46, a fourth water collecting hole 43 is arranged at the top of the flexible double electrode plate 21, a fourth water distribution hole 42 is arranged at the bottom of the flexible double electrode plate 21, and a water distribution trough is arranged on one side of the fourth water distribution hole 42.

[0073] Under the action of the electric field, the metal cations in the wastewater anode chamber 241 move to the alkali chamber through the cation exchange membrane 16, and at the same time, the bipolar membrane 18 causes the hydroxide ions to move toward the alkali chamber, and the metal cations combine with the hydroxide ions to form an alkali solution. The salt anions in the wastewater cathode chamber 242 reach the acid chamber through the anion exchange membrane 20, and at the same time, the bipolar membrane 18 causes the hydrogen ions to reach the acid chamber, and the salt anions combine with the hydrogen ions to form an acid solution. At the same time, the organic macromolecules in the wastewater anode chamber 241 are degraded to form small molecules.

[0074] After being treated by the stack system 1, the wastewater in the wastewater anode chamber 241 and the wastewater cathode chamber 242 are respectively discharged from the wastewater chamber partition 15 and the second water collection hole 38 of the wastewater chamber partition 15, and discharged through the wastewater outlet hole 33 on the cathode plate 22, and returned to the wastewater storage tank 4, completing the wastewater treatment cycle. Similarly, the alkaline solution produced by the reaction in the alkali solution compartment 25 is led out from the first water collection hole 36 of the alkali chamber partition 17, and returned to the alkali solution storage tank 7 through the alkali solution outlet hole 34 on the cathode plate 22, completing the alkali solution concentration cycle. The acidic solution produced by the reaction in the acid solution compartment 26 is discharged from the third water collection hole 40 of the acid chamber partition 19, and then reaches the acid solution storage tank 10 through the acid solution outlet hole 32 of the cathode plate 22, completing the acid solution concentration cycle. The above three treatment methods are subjected to multiple concentration cycles to ensure the pretreatment effect of high-salt organic wastewater.

[0075] In this solution, the anion exchange membrane 20 is a common ion anion exchange membrane 20 rather than a monovalent anion exchange membrane 20 .

[0076] The flexible electrode positive plates 45 are made of titanium coated with ruthenium, and the flexible electrode negative plates 46 are made of stainless steel.

[0077] In order to facilitate the normal operation of the device, the DC power supply system 2 is a constant current source, and the current density of the constant current source is 0mA / cm 2 ~100mA / cm 2 In actual use, since the current density is 0mA / cm 2 ~10mA / cm 2 The working efficiency is low, so the current density of the constant current source is preferably 10mA / cm 2 ~100mA / cm 2 .

[0078] In order to ensure the service life of the anode plate 14 , the anode plate 14 is made of titanium coated with ruthenium.

[0079] The wastewater chamber partition 15 includes a support frame 151 and a support wire mesh 152. The support frame 151 is arranged around the wastewater anode chamber 241, and the support wire mesh 152 is located in the wastewater anode chamber 241. In order to reserve space for the flow of wastewater, the wastewater chamber partition 15 in this solution includes a support wire mesh 152, and in order to facilitate the formation of turbulence in the flow of wastewater and accelerate the synthesis speed of wastewater, a support wire mesh 152 is also arranged in the support frame 151.

[0080] In the wastewater cathode chamber 242 , the support frame 151 is disposed around the wastewater cathode chamber 242 , and the support wire mesh 152 is located in the wastewater cathode chamber 242 .

[0081] In this embodiment, the structures of the acid chamber partition 19 and the alkali chamber partition 17 are the same as the wastewater chamber partition 15, and their purpose is to accelerate the reaction speed of the solutions in the acid chamber and the alkali chamber.

[0082] Embodiment 1:

[0083] In order to conveniently describe the working principle of this device, this scheme takes thiadiazole wastewater containing potassium sulfate as an example. The experimental data are as follows: Figure 17-22 As shown. The solution in the wastewater chamber is thiadiazole wastewater containing potassium sulfate, wherein the thiadiazole content is 478.71 mg / L, wherein the potassium sulfate content is 75685 mg / L, a total of 1000 mL, and the thiadiazole wastewater circulates alone. The solution in the alkali chamber is a dilute solution containing potassium hydroxide, wherein the concentration of potassium hydroxide is 0.005 mol / L, a total of 1000 mL, and the dilute potassium hydroxide solution circulates. The solution in the acid chamber is a dilute solution containing sulfuric acid, wherein the concentration of sulfuric acid is 0.005 mol / L, a total of 1000 mL, and the dilute sulfuric acid solution circulates. At a current density of 50 mA / cm 2 Under the conditions of , after the solution in the wastewater chamber was treated for 210 minutes, the desalination rate of the wastewater was 99.98%, and the degradation rate of thiadiazole was 93.26%. The potassium hydroxide concentration in the alkali chamber was 0.70 mol / L, and the thiadiazole content was 2.14 mg / L. The dilute sulfuric acid concentration in the acid chamber was 0.83 mol / L, and the thiadiazole content was 23.57 mg / L.

[0084] By the attached Fig.18 With attached Fig.19 It can be seen that the MMTD (thiadiazole) in the wastewater anode chamber 241 and the wastewater cathode chamber 242 is difficult to enter the acid solution compartment 26 and the alkali solution compartment 25, ensuring that the final product in the acid solution compartment 26 and the alkali solution compartment 25 is difficult to be contaminated.

[0085] In the scheme, the wastewater chamber is the wastewater anode chamber 241 or the wastewater cathode chamber 242 , the alkali chamber is the alkali solution compartment 25 , and the acid chamber is the acid solution compartment 26 .

[0086] Embodiment 2:

[0087] In this embodiment, the solution in the wastewater chamber is thiadiazole wastewater containing potassium sulfate, wherein the thiadiazole content is 493.00 mg / L, wherein the potassium sulfate content is 76426 mg / L, a total of 1000 mL, and the thiadiazole wastewater is circulated separately. The experimental data are as follows Figure 23-28 As shown. The solution in the alkali chamber is a dilute solution containing potassium hydroxide, the concentration of potassium hydroxide is 0.005 mol / L, a total of 1000 mL, and the dilute potassium hydroxide solution circulates. The solution in the acid chamber is a dilute solution containing sulfuric acid, the concentration of sulfuric acid is 0.005 mol / L, a total of 1000 mL, and the dilute sulfuric acid solution circulates. At a current density of 50 mA / cm 2Under the conditions of , after the solution in the wastewater chamber was treated for 330 minutes, the desalination rate of the wastewater was 99.98%, and the degradation rate of thiadiazole was 95.77%. The potassium hydroxide concentration in the alkali chamber was 0.63 mol / L, and the thiadiazole content was 6.07 mg / L. The dilute sulfuric acid concentration in the acid chamber was 0.81 mol / L, and the thiadiazole content was 5.71 mg / L.

[0088] Embodiment 3:

[0089] In this embodiment, the solution in the wastewater chamber is thiadiazole wastewater containing potassium sulfate, wherein the thiadiazole content is 474.96 mg / L, wherein the potassium sulfate content is 64320 mg / L, a total of 1000 mL, and the thiadiazole wastewater circulates alone. The solution in the alkali chamber is a dilute solution containing potassium hydroxide, wherein the concentration of potassium hydroxide is 0.01 mol / L, a total of 1000 mL, and the dilute potassium hydroxide solution circulates. The solution in the acid chamber is a dilute solution containing sulfuric acid, wherein the concentration of sulfuric acid is 0.01 mol / L, a total of 1000 mL, and the dilute sulfuric acid solution circulates. At a current density of 50 mA / cm 2 Under the conditions of , after the solution in the wastewater chamber was treated for 180 minutes, the desalination rate of the wastewater was 83.74%, and the degradation rate of thiadiazole was 94.12%. The potassium hydroxide concentration in the alkali chamber was 0.63 mol / L, and the thiadiazole content was 2.21 mg / L. The dilute sulfuric acid concentration in the acid chamber was 0.69 mol / L, and the thiadiazole content was 26.51 mg / L.

[0090] Experimental data such as Figure 29-34 shown.

[0091] It can be seen that the device can effectively reduce the content of thiadiazole and convert potassium sulfate into dilute sulfuric acid and potassium hydroxide solution to the greatest extent.

[0092] In summary, the advantages of this scheme are as follows: (1) The multi-membrane stacked electrolysis device for high-salt organic wastewater can recycle salt resources and solve the problem of high-salt organic wastewater being difficult to treat. Under the action of an external electric field, the salt cations and salt anions in the wastewater migrate in a directional manner and enter the alkaline chamber and the acid chamber through the anion and cation exchange membrane respectively, thereby achieving the purpose of recovering salt. At the same time, the salt in the wastewater is removed, thereby improving the efficiency of subsequent biochemical treatment of wastewater. (2) High-salt organic wastewater directly enters the electrode compartment, and organic matter undergoes degradation reaction on the electrode surface, and large-molecule organic matter becomes small-molecule organic matter, thereby improving the biodegradability of wastewater. (3) The stack in the multi-membrane stacked electrolysis device for high-salt organic wastewater adopts a multi-unit stacking "stack" method to increase the wastewater treatment capacity in the system; the use of partitions to form a compartment structure can improve the electrochemical reaction efficiency of the substance; the use of flexible double electrodes in the middle part of the stack can reduce the possibility of liquid leakage in the device; this device configuration can improve the system current efficiency, reduce system energy consumption, and save production costs. (4) The plates and separators used in the multi-membrane stacked electrolysis device for high-salinity organic wastewater are equipped with three parallel groups of water distribution holes / water collection holes to ensure that the wastewater, acid solution, and alkaline solution in the stack system circulate independently, avoiding "cross-talk" between different solutions, thereby achieving the purpose of recovering high-purity acids and alkalis.

[0093] The present invention is not limited to the above-mentioned specific implementation modes. Various changes made by ordinary technicians in this field based on the above-mentioned concepts without creative work are all within the protection scope of the present invention.

Claims

1. A multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater, comprising a stack system (1), a DC power supply system (2) and a liquid circulation system (3), wherein the DC power supply system (2) is electrically connected to the stack system (1), and the stack system (1) is connected to the liquid circulation system (3) via a pipeline, characterized in that: The stack system (1) comprises an anode clamping plate (13) and a cathode clamping plate (23); an anode plate (14) is arranged at one end of the anode clamping plate (13) facing the cathode clamping plate (23); a cathode plate (22) is arranged at one end of the cathode clamping plate (23) facing the anode plate (14); and a plurality of circulation stack units are arranged between the cathode plate (22) and the anode plate (14); The circulation stack unit is provided with a wastewater chamber partition (15), a cation exchange membrane (16), an alkali chamber partition (17), a bipolar membrane (18), an acid chamber partition (19), an anion exchange membrane (20), a wastewater chamber partition (15) and a flexible bipolar electrode plate (21) in sequence along the direction from the anode plate (14) to the cathode plate (22); a wastewater anode chamber (241) is provided between the anode plate (14) and the cation exchange membrane (16); an alkali solution compartment (25) is provided between the cation exchange membrane (16) and the bipolar membrane (18); an acid solution compartment (26) is provided between the bipolar membrane (18) and the anion exchange membrane (20); and a wastewater cathode chamber (242) is provided between the anion exchange membrane (20) and the flexible bipolar electrode plate (21).

2. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The liquid circulation system (3) comprises a wastewater circulation system (301), an alkali liquid circulation system (302) and an acid liquid circulation system (303); the wastewater circulation system (301) comprises a wastewater storage tank (4) and a wastewater circulation pump (5); the wastewater storage tank (4) is connected to the wastewater circulation pump (5) by a pipeline; wastewater pipelines (6) are provided between the wastewater anode chamber (241), the wastewater cathode chamber (242) and the wastewater circulation pump (5); the wastewater anode chamber (241) and the wastewater cathode chamber (242) are connected to the wastewater storage tank (4) by a pipeline; the alkali liquid circulation system (302) comprises an alkali liquid storage tank (7); The alkali liquid circulation pump (8) is connected to the alkali liquid storage tank (7) by a pipeline, an alkali liquid pipeline (9) is provided between the alkali liquid circulation pump (8) and the alkali liquid compartment (25), and the alkali liquid compartment (25) and the alkali liquid storage tank (7) are connected by a pipeline; the acid liquid circulation system (303) comprises an acid liquid storage tank (10) and an acid liquid circulation pump (11), the acid liquid storage tank (10) and the acid liquid circulation pump (11) are connected by a pipeline, an acid liquid pipeline (12) is provided between the acid liquid circulation pump (11) and the acid liquid compartment (26), and the acid liquid compartment (26) and the acid liquid storage tank (10) are connected by a pipeline.

3. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The bottom of the anode plate (14) is provided with an alkali solution inlet hole (28), a wastewater inlet hole (29) and an acid solution inlet hole (30) in sequence.

4. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The top of the cathode plate (22) is provided with an acid outlet hole (32), a wastewater outlet hole (33) and an alkali outlet hole (34).

5. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The alkali chamber partition (17) is provided with a first water distribution hole (35) at the bottom, and the alkali chamber partition (17) is provided with a first water collection hole (36) at the top; the waste water chamber partition (15) is provided with a second water distribution hole (37) at the bottom, and the waste water chamber partition (15) is provided with a second water collection hole (38) at the top; the acid chamber partition (19) is provided with a third water distribution hole (39) at the bottom, and the acid chamber partition (19) is provided with a third water collection hole (40) at the top; the first water distribution hole (35), the second water distribution hole (37) and the third water distribution hole (39) are all provided with water distribution grooves.

6. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 5, characterized in that: The flexible double electrode plate (21) comprises a flexible electrode positive plate (45) and a flexible electrode negative plate (46), an insulating layer is provided between the flexible electrode positive plate (45) and the flexible electrode negative plate (46), a fourth water collection hole (43) is provided at the top of the flexible double electrode plate (21), a fourth water distribution hole (42) is provided at the bottom of the flexible double electrode plate (21), and a water distribution groove is provided on one side of the fourth water distribution hole (42).

7. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 6, characterized in that: The flexible electrode positive plates (45) are all made of titanium-coated ruthenium material, and the flexible electrode negative plates (46) are made of stainless steel.

8. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The DC power supply system (2) is a constant current source, and the current density of the constant current source is 50 mA / cm 2 .

9. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The anode plate (14) is made of titanium coated with ruthenium.

10. The multi-membrane stacked electrolysis device for producing acid and alkali using high-salt organic wastewater according to claim 1, characterized in that: The alkali chamber partition (17) comprises a support frame (151) and a support wire mesh (152); the support frame (151) is arranged around the alkali solution compartment (25); and the support wire mesh (152) is located in the alkali solution compartment (25).

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