System and method for treating ammonia-nitrogen wastewater

Abstract

The invention discloses a system and method for treating ammonia-nitrogen wastewater, and belongs to the technical field of wastewater treatment.The method comprises the steps that pretreatment, air stripping treatment and resin exchange treatment are sequentially conducted on collected ammonia-nitrogen wastewater, and the treated ammonia-nitrogen wastewater is detected; when the ammonia-nitrogen wastewater does not reach the discharge standard, an adsorption column used in the resin exchange treatment is regenerated and cleaned, the ammonia-nitrogen wastewater which does not reach the discharge standard is subjected to resin exchange treatment again until the ammonia-nitrogen wastewater reaches the discharge standard, and meanwhile, waste liquid generated after regeneration treatment is dried; ammonia nitrogen salt solids generated by drying are collected, and generated tail gas and tail gas generated during air stripping are subjected to purification treatment together. The method has the beneficial effects that ammonia and nitrogen are completely separated from the ammonia-nitrogen wastewater by adopting a combined process of ammonia-nitrogen air stripping, resin adsorption and desorption drying, so that the treated ammonia-nitrogen wastewater is harmless and pollution-free, and waste minimization after wastewater treatment is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a system and method for treating ammonia nitrogen wastewater. Background Art

[0002] Ammonia nitrogen wastewater mainly comes from fertilizers, coking, petrochemicals, pharmaceuticals, food, landfills, etc. A large amount of ammonia nitrogen wastewater discharged into water bodies not only causes eutrophication of water bodies and makes the water bodies black and smelly, but also increases the difficulty and cost of water treatment, and even has toxic effects on people and organisms.

[0003] In the prior art, ammonia and nitrogen in ammonia nitrogen wastewater are usually removed by air stripping or adsorption. However, since ammonia and nitrogen are both very soluble in water, the traditional single treatment methods such as ammonia nitrogen air stripping and adsorption can only achieve the concentration of ammonia and nitrogen, but cannot fundamentally remove ammonia and nitrogen. Summary of the invention

[0004] In order to overcome the problem that the prior art can only achieve the concentration of ammonia and nitrogen but cannot fundamentally remove ammonia and nitrogen, the present invention provides a system for treating ammonia nitrogen wastewater, comprising:

[0005] Pretreatment device, used for collecting, storing and acidifying ammonia nitrogen wastewater;

[0006] The air stripping treatment device is connected to the pretreatment device and is used to initially strip ammonia nitrogen from the pretreated ammonia nitrogen wastewater;

[0007] The resin exchange device is connected to the air stripping treatment device and is used to further absorb the residual ammonia and nitrogen in the ammonia nitrogen wastewater after the air stripping treatment, so that the ammonia nitrogen wastewater after the resin exchange treatment meets the discharge standard and is discharged;

[0008] A regeneration and cleaning device, connected to the resin exchange device, for regenerating and cleaning the resin exchange device;

[0009] A drying and collecting device, connected to the regeneration and cleaning device, is used to dry the analytical solution produced during regeneration and collect the ammonia nitrogen salt solid produced after drying;

[0010] The tail gas treatment device is connected to the stripping treatment device and the drying collection device, and is used to treat the tail gas generated during stripping and drying.

[0011] Preferably, the pretreatment device comprises an acidification tank;

[0012] The stripping treatment device includes a stripping tank and a plurality of air blowing pipes. The stripping tank is connected to the acidification tank. The air blowing ends of the air blowing pipes are arranged in the stripping tank by passing through the top of the stripping tank.

[0013] The resin exchange device comprises a cooling acid adjustment tank and a first adsorption column, ..., an Nth adsorption column (N≥2) connected in series, the cooling acid adjustment tank is connected to a stripping tank, and the cooling acid adjustment tank is connected to the first adsorption column, a reflux pump is provided between the first adsorption column and the Nth adsorption column, and the reflux pump is used to send the ammonia nitrogen wastewater that does not meet the discharge standard after passing through the Nth adsorption column back to the first adsorption column for re-resin exchange treatment;

[0014] The regeneration and cleaning device comprises a regeneration agent tank, a decomposition liquid tank and a cleaning tank, wherein the regeneration agent tank is detachably connected to the liquid inlet of the adsorption column, the decomposition liquid tank is detachably connected to the liquid outlet of the adsorption column, and the cleaning tank is detachably connected to both the liquid inlet and the liquid outlet of the adsorption column;

[0015] The drying and collecting device comprises a spray drying tower and a bag dust collector, the analytical liquid tank is connected to the spray drying tower, and the spray drying tower is connected to the bag dust collector;

[0016] The tail gas treatment device includes a dry ammonia nitrogen adsorption filter and an alkaline solution elution tower which are connected in sequence. The dry ammonia nitrogen adsorption filter is connected to a stripping tank and a bag dust collector, and an alkaline solution pump is provided at the bottom of the alkaline solution elution tower for delivering alkaline elution liquid with excessively high ammonia and nitrogen content into an acidification tank.

[0017] In addition, the present invention also provides a method for treating ammonia nitrogen wastewater, comprising:

[0018] Step 1, pre-treating, heating and stripping the collected ammonia nitrogen wastewater in sequence, and performing tail gas purification on the stripping tail gas generated during the stripping treatment;

[0019] Step 2, cooling and acidifying the ammonia nitrogen wastewater treated in step 1 and then performing resin exchange treatment, and testing the ammonia nitrogen wastewater after the resin exchange treatment, and re-performing resin exchange treatment on the ammonia nitrogen wastewater that does not meet the discharge standard until the ammonia nitrogen wastewater meets the discharge standard;

[0020] Step three, using a regeneration agent to regenerate and clean the resin exchange device to obtain a decomposition liquid, drying the decomposition liquid to obtain ammonia nitrogen salt solid and decomposition tail gas, collecting the ammonia nitrogen salt solid, and drying, dust removal and tail gas purification for the decomposition tail gas in sequence.

[0021] Preferably, the pH of the ammonia nitrogen waste liquid after pretreatment is 7-11.

[0022] Preferably, the stripping treatment is to first heat the temperature of the ammonia nitrogen wastewater to 25-60°C, and then strip the ammonia nitrogen wastewater by bubbling, with a bubbling pressure of 0.05-0.08MPa and a stripping time of 30-60min.

[0023] Preferably, after cooling and acid adjustment, the pH of the ammonia nitrogen wastewater is 8-10 and the temperature is 20-30°C;

[0024] The moisture content of the resin in the resin exchange device is 45-50%, the wet apparent density is 0.75-0.90g / ml, the transformation expansion rate is ≤10%, the saturated adsorption capacity of ammonia nitrogen is ≥13mg / g, and the BV of the resin is 0.05-50m 3 .

[0025] Preferably, the resin in the adsorption tower is one or more of H-103, 001×7, 732, and D61.

[0026] Preferably, when the concentration of ammonia and nitrogen in the ammonia nitrogen wastewater after resin exchange treatment is greater than 15 mg / L, the ammonia nitrogen wastewater does not meet the discharge standard.

[0027] Preferably, the regenerant is dilute sulfuric acid with a concentration of 2.5%-10%, and the resin exchange device is regenerated using 1.8-2.5BV of the regenerant at a flow rate of 0.9-1.5BV / h;

[0028] The resin exchange device is then cleaned using a cleaning tank, including forward cleaning and reverse cleaning. The amount of cleaning water for forward cleaning and reverse cleaning is 2.5-5BV, and the cleaning water flow rate is 8-1.5BV / h.

[0029] Preferably, the drying is spray drying, and the pressure of the spray drying is 2-10 MPa.

[0030] Preferably, the tail gas treatment includes dry adsorption filtration and alkaline solution leaching absorption of the stripped tail gas and the analyzed tail gas in sequence, and when the ammonia and nitrogen concentrations of the alkaline solution used in the alkaline solution leaching absorption are greater than 50g / L, the alkaline solution is pumped into the ammonia nitrogen wastewater before pretreatment, and the alkaline solution is reconfigured.

[0031] Beneficial effects:

[0032] The beneficial effects produced by the technical solution of the present invention are as follows: the present invention adopts a combined process of "ammonia nitrogen stripping + resin adsorption + analytical drying" to remove free ammonia nitrogen in the waste liquid by ammonia nitrogen stripping, and then removes ammonia nitrogen in ionic form in the waste liquid by resin adsorption, so that the ammonia nitrogen wastewater after adsorption meets the discharge requirements, the adsorbed saturated resin is eluted by analytical liquid, and the brine separation of the waste liquid is achieved by spray drying, thereby converting the ammonia nitrogen into salts for collection, and the generated stripping tail gas and analytical tail gas are discharged after being purified by tail gas treatment to meet the discharge standard, thereby achieving complete separation of ammonia and nitrogen from the ammonia nitrogen wastewater, making the ammonia nitrogen wastewater harmless and pollution-free after treatment, and minimizing the waste after wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic diagram of the treatment process of ammonia nitrogen wastewater of the present invention;

[0035] Figure 2 It is a schematic diagram of the ion exchange ammonia nitrogen adsorption curve of the resin exchange conditions for the ammonia nitrogen wastewater of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The beneficial effects of the technical solution of the present invention are as follows: the present invention adopts a combined process of "ammonia nitrogen stripping + resin adsorption + analytical drying" to completely separate ammonia and nitrogen from ammonia nitrogen wastewater, making the ammonia nitrogen wastewater harmless and pollution-free after treatment, and minimizing the waste after wastewater treatment. The specific implementation method is as follows:

[0038] like Figure 1 As shown, a system for treating ammonia nitrogen wastewater comprises:

[0039] Pretreatment device, used for collecting, storing and acidifying ammonia nitrogen wastewater;

[0040] The air stripping treatment device is connected to the pretreatment device and is used to initially strip ammonia nitrogen from the pretreated ammonia nitrogen wastewater;

[0041] The resin exchange device is connected to the air stripping treatment device and is used to further absorb the residual ammonia and nitrogen in the ammonia nitrogen wastewater after the air stripping treatment, so that the ammonia nitrogen wastewater after the resin exchange treatment meets the discharge standard and is discharged;

[0042] A regeneration and cleaning device, connected to the resin exchange device, for regenerating and cleaning the resin exchange device;

[0043] A drying and collecting device, connected to the regeneration and cleaning device, is used to dry the analytical solution produced during regeneration and collect the ammonia nitrogen salt solid produced after drying;

[0044] The tail gas treatment device is connected to the stripping treatment device and the drying collection device, and is used to treat the tail gas generated during stripping and drying.

[0045] Specifically, the pretreatment device includes an acidification tank;

[0046] The stripping treatment device includes a stripping tank and a plurality of air blowing pipes. The stripping tank is connected to the acidification tank. The air blowing ends of the air blowing pipes are arranged in the stripping tank by passing through the top of the stripping tank.

[0047] The resin exchange device comprises a cooling acid adjustment tank and a first adsorption column, ..., an Nth adsorption column (N≥2) connected in series, the cooling acid adjustment tank is connected to a stripping tank, and the cooling acid adjustment tank is connected to the first adsorption column, a reflux pump is provided between the first adsorption column and the Nth adsorption column, and the reflux pump is used to send the ammonia nitrogen wastewater that does not meet the discharge standard after passing through the Nth adsorption column back to the first adsorption column for re-resin exchange treatment;

[0048] The regeneration and cleaning device comprises a regeneration agent tank, a decomposition liquid tank and a cleaning tank, wherein the regeneration agent tank is detachably connected to the liquid inlet of the adsorption column, the decomposition liquid tank is detachably connected to the liquid outlet of the adsorption column, and the cleaning tank is detachably connected to both the liquid inlet and the liquid outlet of the adsorption column;

[0049] The drying and collecting device comprises a spray drying tower and a bag dust collector, the analytical liquid tank is connected to the spray drying tower, and the spray drying tower is connected to the bag dust collector;

[0050] The tail gas treatment device includes a dry ammonia nitrogen adsorption filter and an alkaline solution elution tower which are connected in sequence. The dry ammonia nitrogen adsorption filter is connected to a stripping tank and a bag dust collector, and an alkaline solution pump is provided at the bottom of the alkaline solution elution tower for delivering alkaline elution liquid with excessively high ammonia and nitrogen content into an acidification tank.

[0051] In addition, the present invention also provides a method for treating ammonia nitrogen wastewater, comprising:

[0052] Step 1, pre-treating, heating and stripping the collected ammonia nitrogen wastewater in sequence, and performing tail gas purification on the stripping tail gas generated during the stripping treatment;

[0053] Step 2, cooling and acidifying the ammonia nitrogen wastewater treated in step 1 and then performing resin exchange treatment, and testing the ammonia nitrogen wastewater after the resin exchange treatment, and re-performing resin exchange treatment on the ammonia nitrogen wastewater that does not meet the discharge standard until the ammonia nitrogen wastewater meets the discharge standard;

[0054] Step three, using a regeneration agent to regenerate and clean the resin exchange device to obtain a decomposition liquid, drying the decomposition liquid to obtain ammonia nitrogen salt solid and decomposition tail gas, collecting the ammonia nitrogen salt solid, and drying, dust removal and tail gas purification for the decomposition tail gas in sequence.

[0055] Specifically, the pH of the ammonia nitrogen waste liquid after pretreatment is 7-11.

[0056] Specifically, the stripping treatment is to first heat the temperature of the ammonia nitrogen wastewater to 25-60°C, and then strip the ammonia nitrogen wastewater by bubbling, with a bubbling pressure of 0.05-0.08MPa and a stripping time of 30-60min.

[0057] Specifically, after cooling and acid adjustment, the pH of the ammonia nitrogen wastewater is 8-10 and the temperature is 20-30°C;

[0058] The moisture content of the resin in the resin exchange device is 45-50%, the wet apparent density is 0.75-0.90g / ml, the transformation expansion rate is ≤10%, the saturated adsorption capacity of ammonia nitrogen is ≥13mg / g, and the BV of the resin is 0.05-50m 3 .

[0059] Specifically, the model of the resin in the adsorption tower is one or more of H-103, 001×7, 732, and D61.

[0060] Specifically, when the concentration of ammonia and nitrogen in the ammonia nitrogen wastewater after resin exchange treatment is greater than 15 mg / L, the ammonia nitrogen wastewater does not meet the discharge standard.

[0061] Specifically, the regenerant is dilute sulfuric acid with a concentration of 2.5%-10%, and the resin exchange device is regenerated using 1.8-2.5BV of the regenerant at a flow rate of 0.9-1.5BV / h;

[0062] The resin exchange device is then cleaned using a cleaning tank, including forward cleaning and reverse cleaning. The amount of cleaning water for forward cleaning and reverse cleaning is 2.5-5BV, and the cleaning water flow rate is 8-1.5BV / h.

[0063] Specifically, the drying is spray drying, and the pressure of the spray drying is 2-10 MPa.

[0064] Specifically, the exhaust gas treatment includes dry adsorption filtration and alkaline solution leaching absorption of the stripping exhaust gas and the analyzed exhaust gas in sequence, and when the ammonia and nitrogen concentrations of the alkaline solution used in the alkaline solution leaching absorption are greater than 50g / L, the alkaline solution is pumped into the ammonia nitrogen wastewater before pretreatment, and the alkaline solution is reconfigured.

[0065] Optimization of stripping treatment conditions:

[0066] pH value and temperature are two key factors affecting stripping efficiency, among which pH has an impact on equilibrium reaction:

[0067] Most of the ammonia nitrogen in water is in the form of ammonium ions (NH4 + ) and free ammonia (NH3) exist in a state of equilibrium, and the stripping efficiency is directly related to the free ammonia content in water. The equilibrium relationship is as follows:

[0068]

[0069] The percentage distribution between ammonia and ammonium ions can be calculated using the following formula:

[0070]

[0071] Where: K a ———Ionization constant of ammonium ion

[0072] K w ———Ionization constant of water

[0073] K b ———Ionization constant of ammonia

[0074] C——Concentration of substance

[0075] Formula (1) is affected by pH. When the pH is high, the equilibrium moves to the right and the proportion of free ammonia is large. When the pH is around 11, free ammonia accounts for about 90%. It can be seen from formula (2) that according to the principle that the ion product of water is a constant, that is, [H + ]×[OH - ]=K w pH is a constant. It is one of the main factors affecting the percentage of free ammonia in water. As pH increases, the free ammonia in water increases, the equilibrium shifts to the right, and the proportion of free ammonia is larger. When pH = 7, most of the ammonia nitrogen is in the form of NH4 + exists; when the pH rises to about 11, 98% of ammonia nitrogen in the wastewater exists as free ammonia.

[0076] The effect of temperature on the equilibrium reaction is:

[0077] Under a certain pressure, the solubility of gas in wastewater decreases as the temperature increases. Therefore, increasing the temperature is beneficial to the stripping of ammonia nitrogen in the wastewater.

[0078] The dissociation rates of ammonia nitrogen at different pH and temperatures will be tested below. The specific test results are shown in Table 1 below.

[0079] Table 1 Dissociation rate of ammonia nitrogen at different pH and temperature

[0080]

[0081] It can be seen from Table 1 that when the pH is 11, the treatment efficiency of free ammonia nitrogen can reach 98%, and at this time the temperature has no effect on the dissociation rate; when the pH is 10 or below, the treatment efficiency of free ammonia nitrogen increases with the increase of temperature, but in general its dissociation rate is lower than the dissociation rate when the pH is 11.

[0082] Therefore, the present invention places the ammonia nitrogen stripping treatment at the front end for pretreatment, and removes the free ammonia nitrogen in the waste liquid by adjusting the pH and temperature, with the removal efficiency reaching up to 98%.

[0083] Optimization of resin exchange treatment conditions:

[0084] The adsorption method mainly uses the cation or anion exchange groups on the resin surface to exchange with the ions in the solution, adsorbing the ammonia nitrogen ions from the solution to the resin surface, thereby achieving the discharge of ammonia nitrogen wastewater in compliance with the standards. The saturated resin (after adsorbing ammonia nitrogen) is regenerated and analyzed to send the regenerated liquid containing ammonia and nitrogen to the spray drying tower for desalination treatment.

[0085] The key parameters affecting adsorption are the breakthrough volume and the selection of resin regeneration agent. The required parameters will be determined through the following experiments.

[0086] Determination of penetration volume

[0087] Experimental source item: ammonia nitrogen concentration is about 600 mg / L;

[0088] Resin selection: cation exchange resin with sulfonic acid group (-SO3H) on styrene-vinyl copolymer;

[0089] Wet volume method: 10.3 mL of resin was loaded into the column. The flow rate was 3.5 BV / h. Samples were taken every two times the BV. The experimental results are shown in the table below. Figure 2 .

[0090] It can be seen from the breakthrough curve that when the effluent volume reaches 340mL, i.e. 33BV, the ammonia nitrogen value of the effluent has reached 15mg / L, so the design value of the breakthrough volume is 30BV.

[0091] Selection of resin regeneration agent

[0092] The resin that has been saturated with adsorption needs to be washed with acid before it can be regenerated. At the same time, in order to restore the adsorption capacity of the resin, the acid-washed resin needs to be washed with deionized water to pH = 6 before the next cycle of ion exchange operation can be carried out.

[0093] Resin regeneration can be done with hydrochloric acid or sulfuric acid, and sulfuric acid elution can also be done in two steps in accordance with the Technical Regulations for Chemical Water Treatment Design in Chemical Enterprises (HG / T20653-2011). Experimental verification shows that 2.5% sulfuric acid can be used for regeneration at a flow rate of 1BV / h, and the regenerated resin can meet the adsorption capacity of 30BV.

[0094] Experimental measurements show that the regeneration agent flow rate is about 1BV / h, the regeneration agent dosage is about 2BV, and the regeneration time is about 2h; the cleaning water flow rate is about 10BV / h, the cleaning water volume is about 5BV, and the cleaning time is 30min.

[0095] Through the above experiments, the process conditions of the stripping treatment and resin exchange treatment in the present invention are optimized. Combined with the ammonia nitrogen wastewater treatment method of "ammonia nitrogen stripping + resin adsorption + analytical drying" given in the present invention, the ammonia and nitrogen in the ammonia nitrogen wastewater can be completely separated from the wastewater. Combined with the subsequent bag dust removal and tail gas treatment, the waste after the ammonia nitrogen wastewater treatment can be minimized and harmless, so that the entire ammonia nitrogen wastewater treatment can achieve complete separation treatment of ammonia nitrogen wastewater, waste minimization treatment and complete harmless treatment, and the treated wastewater and ammonia nitrogen salt solids can be reused, realizing waste utilization and green production.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for treating ammonia nitrogen wastewater, characterized in that: include: Pretreatment device, used for collecting, storing and acidifying ammonia nitrogen wastewater; A stripping treatment device, connected to the pretreatment device, for initially stripping ammonia nitrogen from the pretreated ammonia nitrogen wastewater; A resin exchange device, connected to the stripping treatment device, is used to further adsorb the residual ammonia and nitrogen in the ammonia nitrogen wastewater after the stripping treatment, so that the ammonia nitrogen wastewater after the resin exchange treatment meets the discharge standard and is discharged; A regeneration and cleaning device, connected to the resin exchange device, for regenerating and cleaning the resin exchange device; A drying and collecting device, connected to the regeneration and cleaning device, used to dry the analytical solution produced during regeneration and collect the ammonia nitrogen salt solid produced after drying; The tail gas treatment device is connected to the stripping treatment device and the drying collection device, and is used to treat the tail gas generated during stripping and drying.

2. A system for treating ammonia nitrogen wastewater according to claim 1, characterized in that: The pretreatment device includes an acidification tank; The stripping treatment device comprises a stripping tank and a plurality of air blowing pipes, wherein the stripping tank is connected to the acidification tank, and the air blowing end of the air blowing pipe is arranged in the stripping tank through the top of the stripping tank; The resin exchange device comprises a cooling acid adjustment tank and a first adsorption column, ..., an Nth adsorption column (N≥2) connected in series, the cooling acid adjustment tank is connected to the stripping tank, and the cooling acid adjustment tank is connected to the first adsorption column, a reflux pump is provided between the first adsorption column and the Nth adsorption column, and the reflux pump is used to send the ammonia nitrogen wastewater that does not meet the discharge standard after passing through the Nth adsorption column back to the first adsorption column for re-resin exchange treatment; The regeneration and cleaning device comprises a regeneration agent tank, a decomposition liquid tank and a cleaning tank, wherein the regeneration agent tank is connected to the liquid inlet of the adsorption column, the decomposition liquid tank is connected to the liquid outlet of the adsorption column, and the cleaning tank is connected to both the liquid inlet and the liquid outlet of the adsorption column; The drying and collecting device comprises a spray drying tower and a bag dust collector, the analytical liquid tank is connected to the spray drying tower, and the spray drying tower is connected to the bag dust collector; The tail gas treatment device comprises a dry ammonia nitrogen adsorption filter and an alkaline solution elution tower which are connected in sequence. The dry ammonia nitrogen adsorption filter is connected to the stripping tank and the bag filter, and an alkaline solution pump is provided at the bottom of the alkaline solution elution tower for delivering alkaline elution liquid with excessively high ammonia and nitrogen content into the acidification tank.

3. A method for treating ammonia nitrogen wastewater using the system described in any one of claims 1 to 2, characterized in that: include: Step 1, pre-treating, heating and stripping the collected ammonia nitrogen wastewater in sequence, and performing tail gas purification treatment on the stripping tail gas generated in the stripping treatment; Step 2, cooling and acidifying the ammonia nitrogen wastewater treated in step 1 and then performing resin exchange treatment, and testing the ammonia nitrogen wastewater after the resin exchange treatment, and re-performing resin exchange treatment on the ammonia nitrogen wastewater that does not meet the discharge standard until the ammonia nitrogen wastewater meets the discharge standard; Step three, using a regeneration agent to regenerate and clean the resin exchange device to obtain a decomposition liquid, drying the decomposition liquid to obtain the ammonia nitrogen salt solid and decomposition tail gas, collecting the ammonia nitrogen salt solid, and drying, dust removal and tail gas purification treatment of the decomposition tail gas in sequence.

4. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: The pH of the ammonia nitrogen waste liquid after pretreatment is 7-11.

5. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: The stripping treatment is to first heat the temperature of the ammonia nitrogen wastewater to 25-60°C, and then strip the ammonia nitrogen wastewater by bubbling, with a bubbling pressure of 0.05-0.08MPa and a stripping time of 30-60min.

6. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: After cooling and acid adjustment, the pH of the ammonia nitrogen wastewater is 8-10 and the temperature is 20-30°C; The resin in the resin exchange device has a water content of 45-50%, a wet apparent density of 0.75-0.90 g / ml, a transformation expansion rate of ≤10%, a saturated adsorption capacity of ammonia nitrogen ≥13 mg / g, and a BV of 0.05-50 m 3 .

7. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: When the concentration of ammonia and nitrogen in the ammonia nitrogen wastewater after the resin exchange treatment is greater than 15 mg / L, the ammonia nitrogen wastewater does not meet the discharge standard.

8. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: The regeneration agent is dilute sulfuric acid with a concentration of 2.5%-10%, and 1.8-2.5 BV of the regeneration agent is used to regenerate the resin exchange device at a flow rate of 0.9-1.5 BV / h; Then, the resin exchange device is cleaned by using the cleaning tank, and the cleaning includes forward cleaning and reverse cleaning. The cleaning water consumption of the forward cleaning and the reverse cleaning is 2.5-5BV, and the cleaning water flow rate is 8-1.5BV / h.

9. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: The drying is spray drying, and the pressure of the spray drying is 2-10 MPa.

10. A method for treating ammonia nitrogen wastewater according to claim 3, characterized in that: The exhaust gas treatment includes sequentially performing dry adsorption filtration and alkaline solution elution absorption on the stripping exhaust gas and the analyzed exhaust gas, and when the ammonia and nitrogen concentrations of the alkaline solution used in the alkaline solution elution absorption are greater than 50 g / L, the alkaline solution is pumped into the ammonia nitrogen wastewater before the pretreatment through an alkaline solution pump, and the alkaline solution is reconfigured.

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