Ammonium sulfate waste liquid resourceful treatment method and system

Abstract

The invention discloses an ammonium sulfate waste liquid resourceful treatment method and system, and relates to the technical field of wastewater treatment. The method comprises the following steps: carrying out microporous filtration treatment on the ammonium sulfate waste liquid to obtain filtered concentrated water and filtered produced water; performing ionization synchronous adsorption treatment on the filtered water to obtain an ammonium sulfate solution A; carrying out deacidification treatment on the ammonium sulfate solution A to obtain an ammonium sulfate solution B and sulfuric acid; when the COD in the ammonium sulfate solution B is less than 20mg / L, performing bipolar membrane electrodialysis treatment on the ammonium sulfate solution B, and recovering to obtain sulfuric acid and ammonia water; when the COD in the ammonium sulfate solution B is greater than or equal to 20mg / L, sequentially carrying out electrochemical activation treatment and bipolar membrane electrodialysis treatment on the ammonium sulfate solution B, and recovering to obtain ammonium persulfate, sulfuric acid and ammonia water. According to the method, high-quality byproducts such as sulfuric acid, ammonia water and ammonium persulfate salt can be obtained, meanwhile, produced water is recycled, resource utilization of the ammonium sulfate waste liquid is achieved, the environmental protection problem is solved, and the treatment cost of the ammonium sulfate waste liquid is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a method and system for resource-based treatment of ammonium sulfate waste liquid. Background Art

[0002] Ammonia nitrogen is a common pollutant in industrial wastewater. High-concentration ammonia nitrogen wastewater mainly comes from coking wastewater, monosodium glutamate wastewater, landfill leachate, aquaculture wastewater, etc. Among the many deammoniation technologies for industrial high-ammonia nitrogen wastewater such as biochemistry, oxidation, ammonia evaporation, ion exchange, chemical precipitation, breakpoint chlorination and membrane separation, gaseous deammoniation membrane separation technology is widely used due to its high mass transfer efficiency, low operating difficulty, low operating cost, and stable effluent compliance.

[0003] Under normal circumstances, after being treated by the gaseous deamination membrane system, high-ammonia nitrogen wastewater is converted into low-ammonia nitrogen or ammonia nitrogen-free wastewater, and ammonium sulfate solution is obtained, which can be used as a nitrogen fertilizer raw material for resource utilization. However, due to the different types of pollutants in different industrial wastewaters, in addition to ammonia nitrogen, it may also contain metal ions, organic pollutants, etc., especially when the wastewater contains surfactants, the water permeability of the deamination membrane will be greatly increased, causing various impurities in the water to pass through the surface of the deamination membrane during operation and enter the acid absorption liquid, thereby forming a byproduct ammonium sulfate solution with more impurities, which is generally manifested as follows: ① The ammonium sulfate solution has many impurities. In addition to ammonium sulfate, it also contains a small amount of COD and Ca 2+ Mg 2+ , suspended matter and a large amount of sulfuric acid; ② The waste liquid is acidic, with a pH below 3; ③ The ammonia nitrogen absorption is unsaturated, and the ammonium sulfate content in the ammonium sulfate solution is low, about 8-22%. Therefore, the ammonium sulfate solution produced after the high-ammonia nitrogen wastewater is treated by the deammoniation membrane system has the risk of not being able to be used as a nitrogen fertilizer raw material. Once it is treated as hazardous waste, the cost of treating each ton of waste liquid will reach hundreds or even thousands of yuan.

[0004] Therefore, in order to avoid increasing the treatment cost by treating ammonium sulfate waste liquid as hazardous waste, the present application proposes a resource treatment method and system for ammonium sulfate waste liquid to achieve resource utilization of ammonium sulfate waste liquid. Summary of the invention

[0005] The main purpose of the present application is to provide a method and system for resource treatment of ammonium sulfate waste liquid, aiming to solve the technical problem that the existing treatment process is difficult to achieve the recycling and utilization of ammonium sulfate waste liquid.

[0006] To achieve the above purpose, the present application proposes a method for recycling ammonium sulfate waste liquid, comprising the following steps:

[0007] The ammonium sulfate waste liquid is subjected to microfiltration treatment to obtain filtered concentrated water and filtered product water;

[0008] The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A;

[0009] Deacidifying the ammonium sulfate solution A to obtain an ammonium sulfate solution B and sulfuric acid;

[0010] When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water;

[0011] When the COD in the ammonium sulfate solution B is ≥20 mg / L, the ammonium sulfate solution B is subjected to electrochemical activation treatment and bipolar membrane electrodialysis treatment in sequence to recover ammonium persulfate, sulfuric acid and ammonia water.

[0012] Optionally, the step of subjecting the ammonium sulfate waste liquid to microfiltration treatment to obtain filtered concentrated water and filtered produced water comprises:

[0013] The ammonium sulfate waste liquid in the raw water tank is filtered through a microporous composite fine filtration membrane to obtain filtered concentrated water and filtered product water;

[0014] The microporous composite fine filtration membrane comprises polytetrafluoroethylene and aluminum oxide in a mass ratio of (15-20):(1-1.5), the membrane pore size is 0.01-0.8 μm, and the filtration accuracy is 5-20 μm;

[0015] The filtered concentrated water is returned to the raw water tank for cyclic treatment, and when the content of suspended matter in the raw water tank is ≥5%, the filtered concentrated water is discharged.

[0016] Optionally, the step of subjecting the filtered water to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A comprises:

[0017] The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50 mg / L, and the impurities are discharged for waste liquid collection and post-treatment;

[0018] During the ionization simultaneous adsorption process, the current density is 5-15A / m 2 The anode is a graphite electrode, a lead oxide electrode or a titanium oxide electrode, and the cathode is a titanium electrode or a platinum electrode; the cathode side is filled with a softening resin, which is a macroporous weakly acidic cation exchange resin with carboxyl and aminomethanesulfonic acid groups connected to a polystyrene copolymer, with a particle size of 0.5-1mm, an exchange capacity of 1600-2000mmol / L, and an operating rate of 10-20BV / h; the anode side is filled with an organic resin, which is an XDA-1G macroporous resin with a particle size of 0.35-1.25mm and a specific surface area of ​​1100-1300m 2 / g, and the operating rate is 2-4BV / h.

[0019] Optionally, in the step of deacidifying the ammonium sulfate solution A to obtain ammonium sulfate solution B and sulfuric acid, a deacidifying membrane is used to deacidify the ammonium sulfate solution A, in which cationic membranes and anionic membranes are alternately arranged, and the cationic membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer polymer skeleton, and the anionic membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether polymer skeleton.

[0020] Optionally, when the COD in the ammonium sulfate solution B is less than 20 mg / L, the step of subjecting the ammonium sulfate solution B to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water comprises:

[0021] When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is treated by a bipolar membrane electrodialysis device to obtain sulfuric acid with a mass concentration of 8-20%, ammonia water with a mass concentration of 10-25%, and ammonium sulfate polar solution;

[0022] The ammonium sulfate polar liquid is subjected to reverse osmosis concentration, wherein the reverse osmosis operating pressure is 10-40 bar and the recovery rate is 50-80%, to obtain reverse osmosis concentrated water and reverse osmosis produced water;

[0023] Returning the reverse osmosis concentrated water to the bipolar membrane electrodialysis device for circulation treatment; reusing the reverse osmosis produced water;

[0024] Among them, the ampere-hour of power in the bipolar membrane electrodialysis device is 0.5-5Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device is 8-16min, the residence time of the acid chamber and the alkali chamber is 4-8min, and the residence time of the electrode chamber is 10-20min.

[0025] Optionally, the components of the cation exchange layer in the bipolar membrane electrodialysis device include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer;

[0026] The modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide is (92.5-96.5): (2-4): (1.5-3.5).

[0027] Optionally, when the COD in the ammonium sulfate solution B is ≥20 mg / L, the step of sequentially subjecting the ammonium sulfate solution B to electrochemical activation treatment and bipolar membrane electrodialysis treatment to recover ammonium persulfate, sulfuric acid and ammonia water comprises:

[0028] When the COD in the ammonium sulfate solution B is ≥ 20 mg / L, the ammonium sulfate solution B is electrochemically activated together with the partially deacidified sulfuric acid at a current density of 350-500 A / m 2 , obtaining ammonium sulfate with a mass concentration of 5-8% and ammonium persulfate with a mass concentration of 10-15%;

[0029] The ammonium sulfate with a mass concentration of 5-8% is introduced into the bipolar membrane electrodialysis device for treatment to recover sulfuric acid and ammonia water.

[0030] Optionally, during the electrochemical activation treatment, an anodic polarization inhibitor is added, wherein the components of the anodic polarization inhibitor include urea and ammonium thiocyanate in a mass ratio of (1.0-1.2):1.

[0031] The present application also proposes a system for resource recovery of ammonium sulfate waste liquid, comprising a raw water tank, a microporous composite fine filtration membrane device, an ionized synchronous adsorption device, an acid removal membrane device, a bipolar membrane electrodialysis device, an RO membrane device and an electrochemical activation device, wherein the water outlet of the raw water tank is connected to the water inlet end of the microporous composite fine filtration membrane device, the water production end of the microporous composite fine filtration membrane device is connected to the water inlet end of the ionized synchronous adsorption device, the concentrated water end of the microporous composite fine filtration membrane device is connected to the water inlet end of the raw water tank, a waste liquid tank is arranged between the raw water tank and the ionized synchronous adsorption device, the external discharge port of the raw water tank and the impurity end of the ionized synchronous adsorption device are both connected to the waste liquid tank, the water outlet end of the ionized synchronous adsorption device is connected to the acid removal membrane device, and the The acid outlet end of the deacidification membrane device is connected to a first sulfuric acid storage tank, which is connected to the liquid inlet end of the electrochemical activation device. The salt outlet end of the deacidification membrane device is respectively connected to the bipolar membrane electrodialysis device and the electrochemical activation device. The electrochemical activation device is connected to an ammonium persulfate storage tank. The salt outlet end of the electrochemical activation device is connected to the bipolar membrane electrodialysis device. The salt outlet end of the bipolar membrane electrodialysis device is connected to the RO membrane device. The concentrated water end of the RO membrane device is connected to the water inlet end of the bipolar membrane electrodialysis device. The water production end of the RO membrane device is connected to an external discharge port. The acid outlet end of the bipolar membrane electrodialysis device is connected to a second sulfuric acid storage tank, and the alkali outlet end of the bipolar membrane electrodialysis device is connected to an ammonia water storage tank.

[0032] Optionally, the ionization synchronous adsorption device is provided with at least one pair of cathode and anode, the cathode and the anode are square and vertically alternately arranged, softening resin and organic adsorption resin are filled between the anode and the cathode, and a water distribution area is provided between the softening resin and the organic adsorption resin.

[0033] This application includes at least the following beneficial effects:

[0034] The present application firstly performs microporous filtration treatment on the ammonium sulfate waste liquid to greatly reduce the content of suspended solids in the filtered water, and then performs ionization synchronous adsorption treatment on the filtered water. After direct current is passed, due to the electrostatic attraction, the positively charged calcium and magnesium ions move to the cathode side and are then adsorbed by the softening resin; most of the negatively charged organic matter (phenols, toluene, phthalates, polycyclic aromatic hydrocarbons, etc.) move to the anode side and are then adsorbed by the organic resin; so that the mass transfer effect of the solute particles is enhanced in the entire ionization synchronous adsorption process, thereby removing the calcium and magnesium impurity ions and the organic impurities simultaneously;

[0035] The present application mainly separates sulfuric acid from ammonium sulfate solution A through deacidification treatment, and recovers sulfuric acid. Then, according to the concentration of COD in ammonium sulfate solution B, ammonium sulfate solution B is treated respectively. When COD in ammonium sulfate solution B is less than 20 mg / L, ammonium sulfate solution B can be directly subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water. When COD in ammonium sulfate solution B is greater than or equal to 20 mg / L, ammonium sulfate solution B is first subjected to electrochemical activation treatment, which can not only degrade organic pollutants, but also electrolytically oxidize ammonium sulfate into ammonium persulfate. Since the oxidation potential of persulfate is 2.01 V, sulfate radicals (SO 4 - ·), its oxidation potential is as high as 3.1V. In comparison, the oxidation ability of persulfate is weak, and its direct oxidation reaction with organic matter is a "slow" reaction, while the electrochemically activated oxidation reaction is a "fast" reaction, which can more efficiently degrade organic matter, thereby greatly reducing the organic matter content, and obtaining ammonium sulfate and ammonium persulfate products with little or no organic matter, and then the ammonium sulfate is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water with higher purity;

[0036] The present application treats the ammonium sulfate waste liquid, produces water for reuse, and obtains high-quality by-products of sulfuric acid, ammonia water and ammonium persulfate salt, which not only realizes resource utilization, but also the by-products can offset a part of the treatment cost, avoiding the problem of high cost of treating the ammonium sulfate waste liquid as hazardous waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0038] Figure 1 This is a schematic diagram of the process for resource recovery of ammonium sulfate waste liquid described in the embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the structure of the ammonium sulfate waste liquid resource treatment system described in the embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the structure of the ionization synchronous adsorption device described in an embodiment of the present application.

[0041] Reference numerals:

[0042] 1-microporous composite fine filtration membrane device; 2-waste liquid tank; 3-ionization synchronous adsorption device; 301-cathode; 302-anode; 303-softening resin; 304-organic adsorption resin; 305-DC power supply; 306-water distribution area; 307-mesh plate; 4-deacidification membrane device; 5-first sulfuric acid storage tank; 6-bipolar membrane electrodialysis device; 7-RO membrane device; 8-second sulfuric acid storage tank; 9-ammonia storage tank; 10-electrochemical activation device; 11-ammonium persulfate storage tank; 12-raw water tank.

[0043] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] In view of the technical problems existing in the above-mentioned prior art, the embodiments of the present application provide a method for recycling ammonium sulfate waste liquid, such as Figure 1 As shown, the following steps are included:

[0046] The ammonium sulfate waste liquid is subjected to microfiltration treatment to obtain filtered concentrated water and filtered product water;

[0047] The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A;

[0048] Deacidifying the ammonium sulfate solution A to obtain an ammonium sulfate solution B and sulfuric acid;

[0049] When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water;

[0050] When the COD in the ammonium sulfate solution B is ≥20 mg / L, the ammonium sulfate solution B is subjected to electrochemical activation treatment and bipolar membrane electrodialysis treatment in sequence to recover ammonium persulfate, sulfuric acid and ammonia water.

[0051] In the specific implementation process, the pH of the ammonium sulfate waste liquid is 0.5-3, the ammonium sulfate content is 5%-10%, the COD content is 60-600 mg / L, and the total hardness of calcium and magnesium is 100-5000 mg / L.

[0052] The present invention firstly performs microporous filtration treatment on the ammonium sulfate waste liquid to greatly reduce the content of suspended solids in the filtered water, and then performs ionization synchronous adsorption treatment on the filtered water. After direct current is passed, due to the electrostatic attraction, the positively charged calcium and magnesium ions move to the cathode side and are then adsorbed by the softening resin; most of the negatively charged organic matter (phenols, toluene, phthalates, polycyclic aromatic hydrocarbons, etc.) move to the anode side and are then adsorbed by the organic resin. The whole process strengthens the mass transfer effect of the solute particles, thereby simultaneously removing the calcium and magnesium impurity ions and the organic impurities. After that, deacidification treatment is performed to separate sulfuric acid from ammonium sulfate solution A and recover the sulfuric acid. Then, according to the COD concentration in ammonium sulfate solution B, ammonium sulfate solution B is treated separately. When COD in ammonium sulfate solution B is less than 20 mg / L, ammonium sulfate solution B can be directly subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water. When COD in ammonium sulfate solution B is greater than or equal to 20 mg / L, ammonium sulfate solution B is first subjected to electrochemical activation treatment, which can not only degrade organic pollutants, but also electrolytically oxidize ammonium sulfate into ammonium persulfate. Since the oxidation potential of persulfate is 2.01 V, sulfate radicals (SO 4 - ) has an oxidation potential as high as 3.1 V. In comparison, persulfate has a lower oxidation potential and its oxidation reaction with organic matter is a "slow" reaction. In the electrochemical activation process, sulfate radicals (SO 4 - ·), which has a stronger strong oxidizing ability and can degrade organic matter more efficiently. It is a "fast" reaction, which greatly reduces the organic content and obtains ammonium sulfate and ammonium persulfate products with little or no organic matter; finally, the ammonium sulfate is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water. This application treats the ammonium sulfate waste liquid, produces water for reuse, and obtains three high-quality by-products of sulfuric acid, ammonia water and ammonium persulfate, which not only realizes resource utilization, but also the by-products can offset part of the treatment cost, avoiding the problem of high cost of treating ammonium sulfate waste liquid as hazardous waste.

[0053] As an implementation method of the present application, the step of subjecting the ammonium sulfate waste liquid to microfiltration to obtain filtered concentrated water and filtered produced water includes:

[0054] The ammonium sulfate waste liquid in the raw water tank is filtered through a microporous composite fine filtration membrane to obtain filtered concentrated water and filtered product water;

[0055] The microporous composite fine filtration membrane comprises polytetrafluoroethylene and aluminum oxide in a mass ratio of (15-20):(1-1.5), the membrane pore size is 0.01-0.8 μm, and the filtration accuracy is 5-20 μm;

[0056] The filtered concentrated water is returned to the raw water tank for cyclic treatment, and when the content of suspended matter in the raw water tank is ≥5%, the filtered concentrated water is discharged.

[0057] In the specific implementation process, the microporous composite fine filtration membrane is a composite membrane that combines an organic phase with an inorganic phase in an enhanced hydrophilic type, and has a high filtration accuracy. After filtering through the microporous composite fine filtration membrane, suspended matter, colloids and other impurities in the ammonium sulfate waste liquid can be filtered out, reducing the concentration of suspended matter in the filtered water to below 1 mg / L.

[0058] Specifically, the concentrated water after microporous composite fine filtration contains suspended matter and a small amount of ammonium sulfate. By returning the filtered concentrated water to the raw water tank for circulation treatment, the ammonium sulfate can be further recycled, and the concentrated water can be discharged regularly by controlling the suspended matter concentration in the raw water tank to be within 5%. That is, when the suspended matter concentration reaches more than 5%, the filtered concentrated water will be discharged, otherwise the concentrated water will not be discharged.

[0059] As an implementation method of the present application, the step of subjecting the filtered water to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A includes:

[0060] The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50 mg / L, and the impurities are discharged for waste liquid collection and post-treatment;

[0061] During the ionization simultaneous adsorption process, the current density is 5-15A / m 2 The anode is a graphite electrode, a lead oxide electrode or a titanium oxide electrode, and the cathode is a titanium electrode or a platinum electrode; the cathode side is filled with a softening resin, which is a macroporous weakly acidic cation exchange resin with carboxyl and aminomethanesulfonic acid groups connected to a polystyrene copolymer, with a particle size of 0.5-1mm, an exchange capacity of 1600-2000mmol / L, and an operating rate of 10-20BV / h; the anode side is filled with an organic resin, which is an XDA-1G macroporous resin with a particle size of 0.35-1.25mm and a specific surface area of ​​1100-1300m 2 / g, and the operating rate is 2-4BV / h.

[0062] The present invention treats filtered water by ionization synchronous adsorption. By loading direct current, under the action of electrostatic attraction, positively charged calcium and magnesium ions move to the cathode side to the softening resin surface, and most of the negatively charged organic matter (phenols, toluene, phthalates, polycyclic aromatic hydrocarbons, etc.) move to the anode side to the surface of the organic matter removal resin. The softening resin adopts a macroporous weakly acidic cation exchange resin, which can effectively remove Ca 2+ Mg 2+ Plasma ensures that the total hardness of the effluent is below 5mg / L, and the organic resin is XDA-1G macroporous resin, which can efficiently remove most organic matter. After ionization synchronous adsorption treatment, the positively charged calcium and magnesium ions and most of the negatively charged organic molecules are directed to move respectively, and the calcium and magnesium impurity ions and organic impurities are removed synchronously. In this synchronous adsorption process, due to the action of the DC electric field, the solute moves in a directional manner, which strengthens the mass transfer between the solute particles and the adsorbent surface, and greatly improves the chemical adsorption between the particles and the adsorption resin. Under the joint action of physical adsorption and chemical adsorption, the mass transfer efficiency is significantly improved compared with conventional direct adsorbent adsorption, so that the effluent organic concentration after ionization synchronous adsorption is lower, COD≤50mg / L, and calcium and magnesium ions are efficiently removed.

[0063] As an implementation method of the present application, in the step of deacidifying the ammonium sulfate solution A to obtain ammonium sulfate solution B and sulfuric acid, a deacidifying membrane is used to deacidify the ammonium sulfate solution A, and the cationic membrane and the anionic membrane are alternately arranged in the deacidifying membrane, and the cationic membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer polymer skeleton, and the anionic membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether polymer skeleton.

[0064] Specifically, the cation membrane is a hydrogen ion selective permeable membrane, which contains negatively charged acidic active groups, can selectively pass cations and block anions, and only pass hydrogen ions, while other cations are not passed. The anion membrane is an anion selective permeable polymer membrane, which contains positively charged alkaline active groups, so it can selectively pass anions and block cations. After deacidification treatment, the sulfuric acid concentration in the ammonium sulfate solution A can be reduced, and the recovery of sulfuric acid can be achieved.

[0065] As an implementation method of the present application, when the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water, comprising:

[0066] When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is treated by a bipolar membrane electrodialysis device to obtain sulfuric acid with a mass concentration of 8-20%, ammonia water with a mass concentration of 10-25%, and ammonium sulfate polar solution;

[0067] The ammonium sulfate polar liquid is subjected to reverse osmosis concentration, wherein the reverse osmosis operating pressure is 10-40 bar and the recovery rate is 50-80%, to obtain reverse osmosis concentrated water and reverse osmosis produced water;

[0068] Returning the reverse osmosis concentrated water to the bipolar membrane electrodialysis device for circulation treatment; reusing the reverse osmosis produced water;

[0069] Among them, the ampere-hour of power in the bipolar membrane electrodialysis device is 0.5-5Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device is 8-16min, the residence time of the acid chamber and the alkali chamber is 4-8min, and the residence time of the electrode chamber is 10-20min.

[0070] As an implementation method of the present application, the components of the cation exchange layer in the bipolar membrane electrodialysis device include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer;

[0071] The modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide is (92.5-96.5): (2-4): (1.5-3.5).

[0072] In the specific implementation process, the bipolar membrane is an ion exchange composite membrane composed of two polymers with opposite charge properties. The bipolar membrane electrodialysis device includes a cation exchange layer, an anion exchange layer and an intermediate catalyst layer. Under the action of a DC electric field, water molecules dissociate into hydrogen ions (H + ) and hydroxide ions (OH - ), these ions migrate to the main solutions on both sides through the cation exchange layer and the anion exchange layer respectively, thereby recovering sulfuric acid, ammonia water and ammonium sulfate polar solution. The ammonium sulfate polar solution is then concentrated by reverse osmosis to obtain reverse osmosis concentrated water and return it to the bipolar membrane electrodialysis device for circulation treatment, and the reverse osmosis produced water can be reused in the system.

[0073] Specifically, the present application adopts a modified polyvinyl alcohol polymer as an intermediate catalytic layer, which can effectively promote the dissociation of water, thereby improving the efficiency of water molecules dissociating into hydrogen ions and hydroxide ions on the intermediate catalytic layer, enhancing the electrodialysis performance, and at the same time reducing the operating voltage of the bipolar membrane, improving the current efficiency, and ultimately obtaining high-quality ammonia water and sulfuric acid.

[0074] As an implementation method of the present application, when the COD in the ammonium sulfate solution B is ≥20 mg / L, the ammonium sulfate solution B is subjected to electrochemical activation treatment and bipolar membrane electrodialysis treatment in sequence to recover ammonium persulfate, sulfuric acid and ammonia water, comprising:

[0075] When the COD in the ammonium sulfate solution B is ≥ 20 mg / L, the ammonium sulfate solution B is electrochemically activated together with the partially deacidified sulfuric acid at a current density of 350-500 A / m 2 , obtaining ammonium sulfate with a mass concentration of 5-8% and ammonium persulfate with a mass concentration of 10-15%;

[0076] The ammonium sulfate with a mass concentration of 5-8% is introduced into the bipolar membrane electrodialysis device for treatment to recover sulfuric acid and ammonia water.

[0077] In the specific implementation process, when the COD in the ammonium sulfate solution B is ≥20 mg / L, the organic matter content in the ammonium sulfate solution B must be reduced first to avoid affecting the quality of the recovered sulfuric acid and ammonia water. In the process of electrochemical activation of the ammonium sulfate solution B, not only can the ammonium sulfate be oxidized into ammonium persulfate, but also the organic pollutants can be degraded. Since the oxidation potential of persulfate is 2.01 V, sulfate radicals (SO 4 - ) has an oxidation potential as high as 3.1 V. In comparison, persulfate has a lower oxidation potential and its oxidation reaction with organic matter is a "slow" reaction. In the electrochemical activation process, sulfate radicals (SO 4 - ·), which has a stronger ability and can degrade organic matter more efficiently, belonging to a "fast" reaction. In addition, in the electrochemical activation process, sulfuric acid obtained after deacidification is added to adjust the pH, and no additional acid or alkali reagent is added to always maintain a strong acidic environment. Under this condition, electrochemical activation mainly produces SO 4 - ·, it has a high oxidation potential and can quickly oxidize and degrade organic matter, thereby significantly reducing the organic matter content in ammonium sulfate solution B.

[0078] As an implementation method of the present application, during the electrochemical activation treatment, an anodic polarization inhibitor is added, wherein the components of the anodic polarization inhibitor include urea and ammonium thiocyanate in a mass ratio of (1.0-1.2):1.

[0079] The present invention adds an anode polarization inhibitor to inhibit the side reaction on the anode during the electrochemical activation process to produce O 2 , so that the main reaction on the anode is to generate persulfate, thereby improving the current efficiency and greatly reducing the operating energy consumption under the condition of the same ammonium persulfate output.

[0080] The embodiment of the present application also provides a system for resource processing of ammonium sulfate waste liquid, comprising a raw water tank 12, a microporous composite fine filtration membrane device 1, an ionization synchronous adsorption device 3, a deacidification membrane device 4, a bipolar membrane electrodialysis device 6, an RO membrane device 7 and an electrochemical activation device 10, wherein the water outlet of the raw water tank 12 is connected to the water inlet end of the microporous composite fine filtration membrane device 1, the water production end of the microporous composite fine filtration membrane device 1 is connected to the water inlet end of the ionization synchronous adsorption device 3, the concentrated water end of the microporous composite fine filtration membrane device 1 is connected to the water inlet end of the raw water tank 12, a waste liquid tank 2 is arranged between the raw water tank 12 and the ionization synchronous adsorption device 3, the external discharge port of the raw water tank 12 and the impurity end of the ionization synchronous adsorption device 3 are both connected to the waste liquid tank 2, and the water outlet end of the ionization synchronous adsorption device 3 is connected to the deacidification membrane device 4 The acid outlet end of the deacidification membrane device 4 is connected to a first sulfuric acid storage tank 5, which is connected to the liquid inlet end of the electrochemical activation device 10. The salt outlet end of the deacidification membrane device 4 is respectively connected to the bipolar membrane electrodialysis device 6 and the electrochemical activation device 10, and the electrochemical activation device 10 is connected to an ammonium persulfate storage tank 11. The salt outlet end of the electrochemical activation device 10 is connected to the bipolar membrane electrodialysis device 6, and the salt outlet end of the bipolar membrane electrodialysis device 6 is connected to the RO membrane device 7. The concentrated water end of the RO membrane device 7 is connected to the water inlet end of the bipolar membrane electrodialysis device 6, and the water production end of the RO membrane device 7 is connected to an external discharge port. The acid outlet end of the bipolar membrane electrodialysis device 6 is connected to a second sulfuric acid storage tank 8, and the alkali outlet end of the bipolar membrane electrodialysis device 6 is connected to an ammonia water storage tank 9.

[0081] The ammonium sulfate waste liquid resource treatment system of the present application includes a raw water tank 12, a microporous composite fine filtration membrane device 1, an ionization synchronous adsorption device 3, a deacidification membrane device 4, a bipolar membrane electrodialysis device 6, an RO membrane device 7 and an electrochemical activation device 10. The ammonium sulfate waste liquid is stored in the raw water tank 12, and first enters the microporous composite fine filtration membrane device 1 for filtration to remove most of the suspended matter. The filtered produced water then enters the deacidification membrane device 4 to reduce the concentration of sulfuric acid. The filtered concentrated water returns to the raw water tank 12 for circulation treatment, and when the concentration of suspended matter in the raw water tank 12 is high, the filtered concentrated water is discharged into the waste liquid tank 2. The sulfuric acid removed by the deacidification membrane device 4 is stored in the first sulfuric acid storage tank 5 to realize the recovery and utilization of sulfuric acid. If the COD in the ammonium sulfate solution B after the deacidification membrane device 4 is less than 20 mg / L, the ammonium sulfate solution B is treated by the bipolar membrane electrodialysis device 6 to obtain ammonia water and stored in the ammonia water storage tank 9 to obtain Sulfuric acid is stored in the second sulfuric acid storage tank 8, and the ammonium sulfate polar liquid is obtained and passed into the RO membrane device 7 for reverse osmosis concentration to obtain reverse osmosis produced water for reuse, and the reverse osmosis concentrated water is returned to the bipolar membrane electrodialysis device 6 for treatment. If the COD in the ammonium sulfate solution B after the deacidification membrane device 4 is ≥20 mg / L, the ammonium sulfate solution B is passed into the electrochemical activation device 10, and a part of the sulfuric acid in the first sulfuric acid storage tank 5 is passed at the same time, and the electrochemical activation is maintained in an acidic environment to oxidize and degrade organic matter to obtain ammonium persulfate products and ammonium sulfate, and then the ammonium sulfate is passed into the bipolar membrane electrodialysis device 6 for treatment, the obtained ammonia water is stored in the ammonia water storage tank 9, the obtained sulfuric acid is stored in the second sulfuric acid storage tank 8, and the obtained ammonium sulfate polar liquid is passed into the RO membrane device 7. After the ammonium sulfate waste liquid is treated by the system, high-quality ammonia water, sulfuric acid, ammonium persulfate and other products can be recovered, thereby realizing the resource utilization of the ammonium sulfate waste liquid.

[0082] As an implementation method of the present application, Figure 3 As shown, the ionization synchronous adsorption device 3 is provided with at least one pair of cathode 301 and anode 302, the cathode 301 and the anode 302 are square and vertically alternately arranged, the anode 302 and the cathode 301 are respectively connected to the positive and negative poles of the external DC power supply 305, and the space between the anode 302 and the cathode 301 is filled with a softening resin 303 and an organic adsorption resin 304, and the filling volume ratio of the softening resin 303 to the organic resin 304 is set according to the calcium and magnesium hardness and the organic concentration, as well as the adsorption capacity of each resin and other parameters, and a water distribution area 306 is provided between the softening resin 303 and the organic resin 304, and a mesh plate 307 is provided at the interface area between the water distribution area 306 and the softening resin 303 and the organic resin 304, respectively, to facilitate the free passage of water molecules, while the softening resin 303 and the organic resin 304 are blocked and isolated.

[0083] As an implementation method of the present application, the acid removal membrane device 4 includes a dialysis chamber, an anion membrane, an acid outlet chamber and a cation membrane, wherein ammonium sulfate solution A simultaneously enters several dialysis chambers to obtain ammonium sulfate solution B, and pure water simultaneously enters several acid outlet chambers to obtain sulfuric acid.

[0084] As an implementation method of the present application, the electrochemical activation device 10 includes an anode chamber and a cathode chamber, wherein the anode chamber is connected to the positive electrode of the power supply, and the cathode chamber is connected to the negative electrode of the power supply. After the ammonium sulfate solution B enters the anode chamber, ammonium persulfate is obtained, and the sulfuric acid separated by the deacidification membrane device 4 enters the cathode chamber.

[0085] As an implementation method of the present application, the bipolar membrane electrodialysis device 6 includes an alkali chamber, a cation exchange layer, a salt chamber, an anion exchange layer and an acid chamber, wherein after the ammonium sulfate solution B enters several salt chambers at the same time, ammonia water is obtained in the alkali chamber, ammonium sulfate polar solution is obtained in the salt chamber, and sulfuric acid is obtained in the acid chamber.

[0086] The above technical solution of the present application is described in detail below in conjunction with specific embodiments.

[0087] Example 1

[0088] A method for recycling ammonium sulfate waste liquid comprises the following steps:

[0089] The ammonium sulfate waste liquid in the raw water tank 12 is filtered by the microporous composite fine filtration membrane device 1 to obtain filtered concentrated water and filtered product water;

[0090] The composition of the membrane in the microporous composite fine filtration membrane device 1 is polytetrafluoroethylene and aluminum oxide, the mass ratio of the two is 17:1.2, the membrane pore size is 0.4 μm, and the filtration accuracy is 12 μm;

[0091] The filtered concentrated water is returned to the raw water tank 12 for cyclic treatment. When the suspended solids content in the raw water tank 12 is ≥5%, the filtered concentrated water is discharged into the waste liquid tank 2;

[0092] The filtered water is passed into the ionization synchronous adsorption device 3 for ionization synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50mg / L, and the impurities are discharged into the waste liquid tank 2 for waste liquid collection and post-treatment;

[0093] In the ionization synchronous adsorption device 3, the cathode side is filled with a softening resin, which is a macroporous weakly acidic cation exchange resin in which carboxyl groups and aminomethanesulfonic acid groups are connected to a polystyrene copolymer, has a particle size of 0.7 mm, an exchange capacity of 1800 mmol / L, and an operating rate of 15 BV / h;

[0094] The anode side is filled with organic resin, which is XDA-1G macroporous resin with a particle size of 0.8 mm and a specific surface area of ​​1200 m 2 / g, operating rate is 5BV / h;

[0095] The ammonium sulfate solution A is deacidified by using a deacidification membrane device 4, wherein the cation membrane and the anion membrane are alternately arranged, the cation membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer macromolecular skeleton, and the anion membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether macromolecular skeleton, to obtain an ammonium sulfate solution B and sulfuric acid; the sulfuric acid is stored in a first sulfuric acid storage tank 5;

[0096] The COD in the ammonium sulfate solution B is 15 mg / L, and the ammonium sulfate solution B is passed into the bipolar membrane electrodialysis device 6 for treatment to obtain sulfuric acid with a mass concentration of 14% and stored in the second sulfuric acid storage tank 8, to obtain ammonia water with a mass concentration of 17% and stored in the ammonia water storage tank 9, and ammonium sulfate polar solution;

[0097] The ammonium sulfate polar liquid is passed into the RO membrane device 7 for reverse osmosis concentration, wherein the reverse osmosis operating pressure is 25 bar and the recovery rate is 65%, thereby obtaining reverse osmosis concentrated water and reverse osmosis produced water;

[0098] The reverse osmosis concentrated water is returned to the bipolar membrane electrodialysis device 6 for circulation treatment; the reverse osmosis produced water is reused in the system;

[0099] Among them, the ampere-hour of the bipolar membrane electrodialysis device 6 is 4.5Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device 6 is 12min, the residence time of the acid chamber and the alkali chamber is 6min, and the residence time of the electrode chamber is 15min;

[0100] The components of the cation exchange layer in the bipolar membrane electrodialysis device 6 include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer; the modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the three is 94.5:3:2.5.

[0101] Example 2

[0102] A method for recycling ammonium sulfate waste liquid comprises the following steps:

[0103] The ammonium sulfate waste liquid in the raw water tank 12 is filtered by the microporous composite fine filtration membrane device 1 to obtain filtered concentrated water and filtered product water;

[0104] The composition of the membrane in the microporous composite fine filtration membrane device 1 is polytetrafluoroethylene and aluminum oxide, the mass ratio of the two is 20:1, the membrane pore size is 0.8 μm, and the filtration accuracy is 20 μm;

[0105] The filtered concentrated water is returned to the raw water tank 12 for cyclic treatment. When the suspended solids content in the raw water tank 12 is ≥5%, the filtered concentrated water is discharged into the waste liquid tank 2;

[0106] The filtered water is passed into the ionization synchronous adsorption device 3 for ionization synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50mg / L, and the impurities are discharged into the waste liquid tank 2 for waste liquid collection and post-treatment;

[0107] In the ionization synchronous adsorption device 3, the cathode side is filled with softening resin, which is a macroporous weakly acidic cation exchange resin with carboxyl and aminomethanesulfonic acid groups connected to a polystyrene copolymer, with a particle size of 1 mm, an exchange capacity of 2000 mmol / L, and an operating rate of 20 BV / h;

[0108] The anode side is filled with organic resin, which is XDA-1G macroporous resin with a particle size of 1.25 mm and a specific surface area of ​​1300 m 2 / g, the operating rate is 4BV / h;

[0109] The ammonium sulfate solution A is deacidified by using a deacidification membrane device 4, wherein the cation membrane and the anion membrane are alternately arranged, the cation membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer macromolecular skeleton, and the anion membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether macromolecular skeleton, to obtain an ammonium sulfate solution B and sulfuric acid; the sulfuric acid is stored in a first sulfuric acid storage tank 5;

[0110] The COD in ammonium sulfate solution B is 25 mg / L. The ammonium sulfate solution B is electrochemically activated and introduced into the sulfuric acid in the first sulfuric acid storage tank 5. At the same time, an anode polarization inhibitor is added. The current density is set to 500 A / m 2 , obtaining ammonium sulfate with a mass concentration of 8% and ammonium persulfate with a mass concentration of 15%; the components of the anodic polarization inhibitor are urea and ammonium thiocyanate with a mass ratio of 1.2:1;

[0111] Then, the ammonium sulfate with a mass concentration of 8% is passed into the bipolar membrane electrodialysis device 6 for treatment to obtain sulfuric acid which is stored in the second sulfuric acid storage tank 8, to obtain ammonia water which is stored in the ammonia water storage tank 9, and the ammonium sulfate polar liquid;

[0112] Among them, the ampere-hour of the bipolar membrane electrodialysis device 6 is 5Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device 6 is 8 minutes, the residence time of the acid chamber and the alkali chamber is 4 minutes, and the residence time of the electrode chamber is 10 minutes. ;

[0113] The components of the cation exchange layer in the bipolar membrane electrodialysis device 6 include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer; the modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the three is 92.5:4:3.5;

[0114] The ammonium sulfate polar liquid is then passed into the RO membrane device 7 for reverse osmosis concentration, wherein the reverse osmosis operating pressure is 40 bar and the recovery rate is 80%, to obtain reverse osmosis concentrated water and reverse osmosis produced water; the reverse osmosis concentrated water is returned to the bipolar membrane electrodialysis device 6 for circulation treatment, and the reverse osmosis produced water is reused in the system.

[0115] Example 3

[0116] A method for recycling ammonium sulfate waste liquid comprises the following steps:

[0117] The ammonium sulfate waste liquid in the raw water tank 12 is filtered by the microporous composite fine filtration membrane device 1 to obtain filtered concentrated water and filtered product water;

[0118] The composition of the membrane in the microporous composite fine filtration membrane device 1 is polytetrafluoroethylene and aluminum oxide, the mass ratio of the two is 15:1.5, the membrane pore size is 0.01 μm, and the filtration accuracy is 5 μm;

[0119] The filtered concentrated water is returned to the raw water tank 12 for cyclic treatment. When the suspended solids content in the raw water tank 12 is ≥5%, the filtered concentrated water is discharged into the waste liquid tank 2;

[0120] The filtered water is passed into the ionization synchronous adsorption device 3 for ionization synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50mg / L, and the impurities are discharged into the waste liquid tank 2 for waste liquid collection and post-treatment;

[0121] In the ionization synchronous adsorption device 3, the anode side is filled with a softening resin, which is a macroporous weakly acidic cation exchange resin in which carboxyl groups and aminomethanesulfonic acid groups are connected to a polystyrene copolymer, has a particle size of 0.5 mm, an exchange capacity of 1600 mmol / L, and an operating rate of 10 BV / h;

[0122] The cathode side is filled with organic resin, which is XDA-1G macroporous resin with a particle size of 0.35 mm and a specific surface area of ​​1100 m 2 / g, the operating rate is 2BV / h;

[0123] The ammonium sulfate solution A is deacidified by using a deacidification membrane device 4, wherein the cation membrane and the anion membrane are alternately arranged, the cation membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer macromolecular skeleton, and the anion membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether macromolecular skeleton, to obtain an ammonium sulfate solution B and sulfuric acid; the sulfuric acid is stored in a first sulfuric acid storage tank 5;

[0124] When the COD in the ammonium sulfate solution B is 16 mg / L, the ammonium sulfate solution B is passed into the bipolar membrane electrodialysis device 6 for treatment to obtain sulfuric acid with a mass concentration of 8% and stored in the second sulfuric acid storage tank 8, to obtain ammonia water with a mass concentration of 10% and stored in the ammonia water storage tank 9, and ammonium sulfate polar solution;

[0125] The ammonium sulfate polar liquid is passed into the RO membrane device 7 for reverse osmosis concentration, wherein the reverse osmosis operating pressure is 10 bar and the recovery rate is 50%, to obtain reverse osmosis concentrated water and reverse osmosis produced water;

[0126] The reverse osmosis concentrated water is returned to the bipolar membrane electrodialysis device 6 for circulation treatment; the reverse osmosis produced water is reused in the system;

[0127] Among them, the ampere-hour of the bipolar membrane electrodialysis device 6 is 3Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device 6 is 16 minutes, the residence time of the acid chamber and the alkali chamber is 8 minutes, and the residence time of the electrode chamber is 20 minutes;

[0128] The components of the cation exchange layer in the bipolar membrane electrodialysis device 6 include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer; the modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the three is 96.5:2:1.5.

[0129] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for recycling ammonium sulfate waste liquid, characterized in that: The following steps are involved: The ammonium sulfate waste liquid is subjected to microfiltration treatment to obtain filtered concentrated water and filtered product water; The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A; Deacidifying the ammonium sulfate solution A to obtain an ammonium sulfate solution B and sulfuric acid; When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water; When the COD in the ammonium sulfate solution B is ≥20 mg / L, the ammonium sulfate solution B is subjected to electrochemical activation treatment and bipolar membrane electrodialysis treatment in sequence to recover ammonium persulfate, sulfuric acid and ammonia water.

2. The method for recycling ammonium sulfate waste liquid according to claim 1, wherein: The step of subjecting the ammonium sulfate waste liquid to microporous filtration to obtain filtered concentrated water and filtered produced water comprises: The ammonium sulfate waste liquid in the raw water tank is filtered through a microporous composite fine filtration membrane to obtain filtered concentrated water and filtered product water; The microporous composite fine filtration membrane comprises polytetrafluoroethylene and aluminum oxide in a mass ratio of (15-20):(1-1.5), the membrane pore size is 0.01-0.8 μm, and the filtration accuracy is 5-20 μm; The filtered concentrated water is returned to the raw water tank for cyclic treatment, and when the content of suspended matter in the raw water tank is ≥5%, the filtered concentrated water is discharged.

3. The method for recycling ammonium sulfate waste liquid according to claim 1, wherein: The step of subjecting the filtered water to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A comprises: The filtered water is subjected to ionization and synchronous adsorption treatment to obtain ammonium sulfate solution A and impurities; COD in the ammonium sulfate solution A is ≤50 mg / L, and the impurities are discharged for waste liquid collection and post-treatment; During the ionization simultaneous adsorption process, the current density is 5-15A / m 2 The anode is a graphite electrode, a lead oxide electrode or a titanium oxide electrode, and the cathode is a titanium electrode or a platinum electrode; the cathode side is filled with a softening resin, which is a macroporous weakly acidic cation exchange resin with carboxyl and aminomethanesulfonic acid groups connected to a polystyrene copolymer, with a particle size of 0.5-1mm, an exchange capacity of 1600-2000mmol / L, and an operating rate of 10-20BV / h; the anode side is filled with an organic resin, which is an XDA-1G macroporous resin with a particle size of 0.35-1.25mm and a specific surface area of ​​1100-1300m 2 / g, and the operating rate is 2-4BV / h.

4. The method for recycling ammonium sulfate waste liquid according to claim 1, wherein: In the step of deacidifying the ammonium sulfate solution A to obtain ammonium sulfate solution B and sulfuric acid, a deacidifying membrane is used to deacidify the ammonium sulfate solution A, in which a cationic membrane and an anionic membrane are alternately arranged, the cationic membrane is a composite material in which sulfonic acid groups and arsenic acid groups are polymerized as fixed groups on a non-fluorinated polymer macromolecular skeleton, and the anionic membrane is a composite material in which aromatic amino groups are polymerized as fixed groups on a polyphenylene ether macromolecular skeleton.

5. The method for recycling ammonium sulfate waste liquid according to claim 1, characterized in that: When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is subjected to bipolar membrane electrodialysis treatment to recover sulfuric acid and ammonia water, comprising: When the COD in the ammonium sulfate solution B is less than 20 mg / L, the ammonium sulfate solution B is treated by a bipolar membrane electrodialysis device to obtain sulfuric acid with a mass concentration of 8-20%, ammonia water with a mass concentration of 10-25%, and ammonium sulfate polar solution; The ammonium sulfate polar liquid is subjected to reverse osmosis concentration, wherein the reverse osmosis operating pressure is 10-40 bar and the recovery rate is 50-80%, to obtain reverse osmosis concentrated water and reverse osmosis produced water; Returning the reverse osmosis concentrated water to the bipolar membrane electrodialysis device for circulation treatment; reusing the reverse osmosis produced water; Among them, the ampere-hour of power in the bipolar membrane electrodialysis device is 0.5-5Ah / L; the residence time of the salt chamber in the bipolar membrane electrodialysis device is 8-16min, the residence time of the acid chamber and the alkali chamber is 4-8min, and the residence time of the electrode chamber is 10-20min.

6. The method for recycling ammonium sulfate waste liquid according to claim 5, characterized in that: The components of the cation exchange layer in the bipolar membrane electrodialysis device include perfluorosulfonic acid polymer, the components of the anion exchange layer include polybenzimidazole, and the components of the catalyst layer include modified polyvinyl alcohol polymer; The modified polyvinyl alcohol polymer is a mixture of polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide, and the mass ratio of the polyvinyl alcohol polymer, nano zinc oxide and silicon dioxide is (92.5-96.5): (2-4): (1.5-3.5).

7. The method for recycling ammonium sulfate waste liquid according to claim 6, characterized in that: When the COD in the ammonium sulfate solution B is ≥20 mg / L, the ammonium sulfate solution B is subjected to electrochemical activation treatment and bipolar membrane electrodialysis treatment in sequence to recover ammonium persulfate, sulfuric acid and ammonia water, comprising: When the COD in the ammonium sulfate solution B is ≥ 20 mg / L, the ammonium sulfate solution B is electrochemically activated together with the partially deacidified sulfuric acid at a current density of 350-500 A / m 2 , obtaining ammonium sulfate with a mass concentration of 5-8% and ammonium persulfate with a mass concentration of 10-15%; The ammonium sulfate with a mass concentration of 5-8% is introduced into the bipolar membrane electrodialysis device for treatment to recover sulfuric acid and ammonia water.

8. The method for recycling ammonium sulfate waste liquid according to claim 7, characterized in that: During the electrochemical activation treatment, an anode polarization inhibitor is added, wherein the components of the anode polarization inhibitor include urea and ammonium thiocyanate in a mass ratio of (1.0-1.2):

1.

9. An ammonium sulfate waste liquid resource treatment system, used for implementing the ammonium sulfate waste liquid resource treatment method according to any one of claims 1 to 8, characterized in that: The system comprises a raw water tank, a microporous composite fine filtration membrane device, an ionization synchronous adsorption device, a deacidification membrane device, a bipolar membrane electrodialysis device, an RO membrane device and an electrochemical activation device. The water outlet of the raw water tank is connected to the water inlet end of the microporous composite fine filtration membrane device, the water production end of the microporous composite fine filtration membrane device is connected to the water inlet end of the ionization synchronous adsorption device, the concentrated water end of the microporous composite fine filtration membrane device is connected to the water inlet end of the raw water tank, a waste liquid tank is arranged between the raw water tank and the ionization synchronous adsorption device, the external discharge port of the raw water tank and the impurity end of the ionization synchronous adsorption device are both connected to the waste liquid tank, the water outlet end of the ionization synchronous adsorption device is connected to the deacidification membrane device, and the acid outlet end of the deacidification membrane device is connected to the acid liquid outlet end of the deacidification membrane device. The outlet end is connected to a first sulfuric acid storage tank, the first sulfuric acid storage tank is connected to the liquid inlet end of the electrochemical activation device, the brine outlet end of the deacidification membrane device is respectively connected to the bipolar membrane electrodialysis device and the electrochemical activation device, the electrochemical activation device is connected to an ammonium persulfate storage tank, the brine outlet end of the electrochemical activation device is connected to the bipolar membrane electrodialysis device, the brine outlet end of the bipolar membrane electrodialysis device is connected to the RO membrane device, the concentrated water end of the RO membrane device is connected to the water inlet end of the bipolar membrane electrodialysis device, the water production end of the RO membrane device is connected to an external discharge port, the acid outlet end of the bipolar membrane electrodialysis device is connected to a second sulfuric acid storage tank, and the alkali outlet end of the bipolar membrane electrodialysis device is connected to an ammonia water storage tank.

10. The ammonium sulfate waste liquid resource treatment system according to claim 9, characterized in that: The ionization synchronous adsorption device is provided with at least one pair of cathode and anode, the cathode and the anode are square and vertically alternately arranged, softening resin and organic adsorption resin are filled between the anode and the cathode, and a water distribution area is provided between the softening resin and the organic adsorption resin.

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