A nitrogen resource thermal extraction and recovery system

Abstract

The present invention discloses a nitrogen resource thermal extraction and recovery system, which includes a pretreatment unit, an analysis unit, a deammoniation unit, an ammonia absorption unit, a crystallization and dehydration unit and other auxiliary units such as steam preparation, tail gas purification, concentrated slag precipitation, and pickling connected in sequence. The present invention transfers ammonia nitrogen in the liquid phase to the vapor phase by physical methods, and then chemically reacts with ammonia nitrogen in the vapor phase in the liquid phase by external addition to generate an ammonium bicarbonate solution. After the ammonium bicarbonate solution is transitionally saturated, crystals are precipitated, and solid ammonium bicarbonate is obtained by centrifugal dehydration. The system not only realizes the recovery of nitrogen resources in landfill leachate and anaerobic fermentation slurry of kitchen sludge, but also greatly reduces the engineering investment and operation cost of the subsequent sewage treatment system, achieving the goal of energy saving and consumption reduction. The system is also suitable for nitrogen resource recovery in other types of high-ammonia nitrogen wastewater such as coal chemical industry.

Description

Technical Field

[0001] The invention relates to the technical field of garbage leachate and kitchen sludge anaerobic fermentation biogas slurry treatment, and in particular to a nitrogen resource thermal extraction and recovery system. Background Art

[0002] Ammonia nitrogen is a long-term pollutant in landfill leachate, and as the landfill time increases, the ammonia nitrogen concentration gradually increases. The ammonia nitrogen concentration of old leachate that has been landfilled for more than 10 years can be as high as 3000 mg / L or more. With the increase in the use time of landfills and the development of waste incineration power generation in the past 10 years, the aging of landfill leachate has become a focus of the problem. Aged leachate has low COD Cr , high NH 3 -N, TN characteristics, B / C is generally lower than 0.3, C / N ratio ≤3 or even lower; the sludge after anaerobic fermentation of fresh leachate from incineration plants and the sludge after anaerobic fermentation of food waste have similar water quality characteristics to those of old leachate from landfills.

[0003] Landfill leachate and anaerobic digestion of kitchen sludge generally need to be treated to meet relevant standards before they can be discharged into urban sewers or water bodies. Table 2 of the "Pollutant Emission Standard for Municipal Waste Landfills" (GB16889-2008) stipulates that the emission of nitrogen pollutants in landfill leachate should be NH 3 -N≤25mg / L, TN≤40mg / L; "Water Quality Standard for Sewage Discharge into Urban Sewers" (GB) requires NH 3 -N≤45mg / L, TN≤60mg / L. High concentration of ammonia nitrogen and low C / N ratio bring great difficulties to the treatment of leachate and anaerobic fermentation of food sludge. The cost of adding carbon source to treat old leachate or anaerobic fermentation of food sludge with imbalanced C / N ratio in landfills by membrane bioreactor often accounts for more than 50% of the operating cost, and the system has poor resistance to water volume and water quality shock load, and the effluent water quality is unstable. Therefore, it is urgent to develop a new process system for the pretreatment of landfill leachate or anaerobic fermentation of food sludge, which can reduce the nitrogen load of the subsequent biological treatment system and realize the resource utilization of nitrogen at the same time. Summary of the invention

[0004] The purpose of the present invention is to treat NH4+ in anaerobic fermentation liquid of garbage leachate and kitchen sludge. 3 -N concentration is high, COD is low, C / N ratio is unbalanced and its treatment requirements provide a complete set of nitrogen resource thermal extraction and recovery system, through the thermal decomposition of bicarbonate ions, negative pressure stripping of free ammonia, CO 2Through methods such as absorption, crystallization of ammonium bicarbonate solution and solid-liquid separation, the ammonia nitrogen in the landfill leachate and anaerobic fermentation liquid of food sludge is recovered as ammonium bicarbonate product, which is sold as high-quality fertilizer. At the same time, the nitrogen load of the subsequent sewage treatment system is reduced, and the project investment is reduced; the amount of external carbon source is saved, and the operating cost is saved; the membrane scaling phenomenon of the MBR sewage treatment system is alleviated, the stability of the sewage treatment system operation is improved, and the maintenance cost is reduced.

[0005] The technical solution of the present invention is as follows: a nitrogen resource thermal extraction and recovery system, characterized in that the system comprises:

[0006] Pretreatment unit: pre-treating the garbage leachate and the anaerobic fermentation liquid of the kitchen sludge to form ammonia-containing wastewater entering the subsequent unit, wherein the COD of the ammonia-containing wastewater is ≤10000mg / L and the SS is ≤1000mg / L;

[0007] The decomposition unit is connected to the pretreatment unit, and the decomposition unit includes a preheater and a decomposition reaction tower. The upper part of the decomposition reaction tower is provided with a packing area, and the lower part is provided with a water collection area and a sludge hopper. The ammonia-containing wastewater enters the decomposition reaction tower after being preheated. The preheated ammonia-containing wastewater and the ammonia-containing steam refluxed from the deammonification unit undergo a heat exchange reaction in the packing area, so that the temperature of the ammonia-containing wastewater is further increased, and the bicarbonate ions in the ammonia-containing wastewater are decomposed into Ions and CO 2 , ions react with calcium and magnesium ions in ammonia-containing wastewater to form carbonate precipitates, CO 2 The ammonia-containing wastewater is collected at the top of the analytical reaction tower together with the ammonia-containing steam, and is transported to the ammonia absorption unit through the top of the analytical reaction tower; the ammonia-containing wastewater in the analytical reaction tower is lifted to the deammoniation unit by a water pump;

[0008] A deamination unit connected to the analytical unit, the deamination unit comprising a deamination tower and a water pump; a packing area is provided at the top of the deamination tower, a water collection area is provided at the bottom, an external steam end is provided at the bottom of the packing area of ​​the deamination tower, the steam output port at the top of the deamination tower is connected to the steam reflux end of the analytical reaction tower, and the wastewater input end at the top of the packing area of ​​the deamination tower is connected to the wastewater output end of the analytical reaction tower; after the ammonia-containing wastewater of the analytical reaction tower enters the deamination tower, it undergoes a stripping deamination reaction with the external steam in the packing area, the ammonia nitrogen in the liquid phase enters the vapor phase, the ammonia-containing vapor is collected at the top of the deamination tower, and refluxes from the top of the deamination tower to the analytical reaction tower of the analytical unit;

[0009] The ammonia absorption unit is connected to the decomposition reaction tower of the decomposition unit. The ammonia absorption unit comprises a condenser, a gas-liquid separator, a reflux pump, an ammonia recovery tower, a circulating water pump, a cooler, an ammonia extraction mixing device, a discharge pump, and a tail gas recovery and treatment device. The ammonia-containing steam at the top of the decomposition reaction tower of the decomposition unit is condensed by the condenser, and the ammonia-containing gas is led to the ammonia recovery tower, and the condensate is refluxed to the decomposition tower or ammonia recovery tower of the decomposition unit; the ammonia recovery tower is injected with water, and CO is introduced into the ammonia recovery tower. 2 , ammonia and CO in ammonia-containing gas 2 The reaction is carried out in an ammonia recovery tower to generate an ammonium bicarbonate solution, and the transitional saturated ammonium bicarbonate solution generated in the ammonia recovery tower is pumped to a crystallization dehydration unit by a discharge pump, and the remaining gas in the ammonia recovery tower is sent to a tail gas recovery and treatment device for tail gas treatment;

[0010] A crystallization dehydration unit is connected to the ammonia absorption unit, and is used to dehydrate the transitional saturated ammonium bicarbonate solution to form ammonium bicarbonate solid, and the dehydrated filtrate is returned to the ammonia recovery tower.

[0011] Furthermore, the pretreatment unit adopts different pretreatment processes according to different treatment objects. The pretreatment unit includes a landfill leachate pretreatment unit and a food sludge anaerobic fermentation biogas slurry pretreatment unit. The landfill leachate pretreatment unit adopts anaerobic + sedimentation or filtration pretreatment or anaerobic MBR pretreatment for fresh leachate from a landfill or leachate from a waste incineration plant, and adopts sedimentation or filtration pretreatment for aged leachate from a landfill; the food sludge anaerobic fermentation biogas slurry pretreatment unit adopts centrifugal or plate and frame dehydration for the food sludge anaerobic fermentation biogas slurry, and adopts flotation pretreatment for the dehydrated filtrate.

[0012] Furthermore, the first input end of the preheater is connected to the balance water tank, the second input end is connected to the water outlet at the bottom of the deamination tower through a water pump, the first output end of the preheater is connected to the input end of the deamination reaction tower, the second output end is connected to the water outlet pipe, the high-temperature wastewater at the bottom of the deamination tower is pumped to the preheater of the deamination unit by a water pump, and the ammonia-containing wastewater in the balance water tank flows into the deamination reaction tower after preheating.

[0013] Furthermore, the sludge hopper of the analytical reaction tower is connected to the concentrated residue settling tank through a sludge pump, and the sludge brought in by the wastewater and the sludge generated during the analytical reaction are collected in the sludge hopper and regularly discharged to the concentrated residue settling tank through the sludge pump.

[0014] Furthermore, in the ammonia absorption unit, the input end of the condenser is connected to the analysis unit through a pipeline, the output end of the condenser is connected to the gas-liquid separator, the liquid outlet end of the gas-liquid separator is connected to the deammoniation tower of the deammoniation unit, and the gas outlet end of the gas-liquid separator is connected to the ammonia recovery tower.

[0015] Furthermore, an air outlet is provided at the top of the ammonia recovery tower, and the air outlet at the top of the ammonia recovery tower is connected to the air inlet of the tail gas recovery tower. A spray head is provided at the upper part of the tail gas recovery tower, and the spray head is connected to the water inlet at the upper end of the tail gas recovery tower. A water outlet is provided at the lower end of the tail gas recovery tower, and the water outlet is connected to the water inlet at the upper end of the ammonia recovery tower through a water pump. The residual gas at the top of the ammonia recovery tower is introduced into the tail gas recovery tower, and is eluted with tap water, and the elution liquid flows back to the ammonia recovery tower.

[0016] Furthermore, a circulating water outlet is provided at the bottom of the ammonia recovery tower, and the circulating water outlet is connected back to the upper part of the ammonia recovery tower through a circulating water pump, a cooler and an ammonia extraction mixing device. The ammonia extraction mixing device is also connected to the gas outlet end of the gas-liquid separator so as to preliminarily cool the gas-liquid mixture in the ammonia recovery tower, control the amount of tap water added to the ammonia recovery tower so that the ammonium bicarbonate solution reaches a saturated state, and at the same time form a negative pressure environment in the ammonia extraction mixing device, and introduce the gas output from the gas outlet end of the gas-liquid separator into the gas-liquid mixture of the circulation loop and then enter the ammonia recovery tower.

[0017] Furthermore, a tail gas outlet is provided at the top of the tail gas recovery tower, and the tail gas outlet is connected to the tail gas purification tower through an induced draft fan. A water inlet is provided at the upper end of the tail gas purification tower, and pickling liquid is injected into the water inlet of the tail gas purification tower. The top outlet of the tail gas purification tower is connected to the biological reaction tank through the induced draft fan. The tail gas after elution in the tail gas recovery tower is introduced into the tail gas purification tower through the induced draft fan, and after pickling, it is led to the aerobic zone of the biological reaction tank of the sewage treatment system 1 to 3m below the liquid.

[0018] Furthermore, the crystallization dehydration unit includes a slurry tank, which has an agitator inside. The bottom outlet of the slurry tank is connected to a centrifugal dehydrator, which is used to dehydrate the transitional saturated ammonium bicarbonate solution generated by the ammonia recovery tower. The dehydrated filtrate is stored in a mother liquor pool and pumped to the ammonia recovery tower by a mother liquor pump. The dehydrated ammonium bicarbonate solid is transported to the baler by a conveyor.

[0019] Furthermore, the ammonia recovery tower, condenser, analytical reaction tower and deamination tower are placed in a negative pressure state by a negative pressure device, and the stripping reaction of the deamination tower is carried out under a negative pressure state (50000Pa to 70000Pa).

[0020] The present invention can convert nitrogen in landfill leachate and anaerobic fermentation of kitchen sludge into ecological ammonia fertilizer through thermal extraction technology and physical and chemical methods, which not only realizes the resource utilization of nitrogen, but also reduces the investment and operation costs of sewage treatment projects. The economic and social benefits of the project are very significant. The system is also suitable for nitrogen resource recovery in other types of high-ammonia nitrogen wastewater such as coal chemical industry. Compared with existing deamination technologies such as air stripping, chemical precipitation, oxidation, etc., the beneficial effects of the present invention are as follows:

[0021] 1. The thermal extraction and recovery system for nitrogen resources in landfill leachate and anaerobic fermentation slurry of kitchen sludge provided by the present invention converts nitrogen in landfill leachate and anaerobic fermentation slurry of kitchen sludge into high-purity ammonium bicarbonate (NH 4 HCO 3 ) products to realize resource utilization of nitrogen;

[0022] 2. The thermal extraction and recovery system for nitrogen resources in the anaerobic fermentation of landfill leachate and kitchen sludge provided by the present invention can significantly reduce the nitrogen load of the sewage biological treatment system and reduce the engineering investment of the sewage treatment system; it can improve the C / N ratio of the leachate (anaerobic fermentation slurry), create good water quality conditions for subsequent biological denitrification treatment, reduce the amount of external carbon source for biological denitrification, and save operating costs;

[0023] 3. The thermal extraction and recovery system for nitrogen resources in the anaerobic fermentation of landfill leachate and kitchen sludge provided by the present invention can recover Ca in the raw water of leachate (biogas slurry) 2+ Mg 2+ , with CaCO 3 MgCO 3 The leachate (biogas slurry) after morphological removal and steam stripping deammoniation pretreatment has the characteristics of low calcium and magnesium ion concentration, low TN concentration, and coordinated COD and TN ratio, which is beneficial to the operation of MBR biological reactor and ultrafiltration membrane components, can alleviate membrane scaling, reduce the frequency of membrane cleaning, and extend the service life of the membrane, thereby reducing operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a system for treating aged leachate from a landfill by stripping and deammoniation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific embodiments.

[0026] Example

[0027] See also Figure 1 , Figure 1 The process flow of stripping and deammoniation treatment of old landfill leachate is shown, where:

[0028] In the pretreatment unit, fresh leachate from landfill or leachate from waste incineration plant is pretreated by anaerobic + sedimentation (or filtration) or anaerobic MBR, and old leachate from landfill is pretreated by sedimentation or filtration; anaerobic fermentation of food sludge is dehydrated by centrifugation or plate and frame, and the dehydrated filtrate is pretreated by flotation, in order to control the COD≤10000mg / L and SS≤1000mg / L entering the subsequent unit. The leachate or biogas slurry treated by the pretreatment unit is stored in the balance water tank 1 and lifted to the analysis unit by the sewage pump.

[0029] The analysis unit is connected to the pretreatment unit, and the analysis unit includes a preheater 2, an analysis reaction tower 3, a concentrated residue precipitation tank, a water pump, etc. The pretreated leachate or biogas slurry is preheated to raise its temperature to 55-65°C; the ammonia-containing wastewater enters the analysis reaction tower 3 after preheating; a packing area is arranged at the top of the analysis reaction tower 3, and a water collection area and a sludge hopper are arranged at the bottom. The preheated wastewater entering the analysis reaction tower and the refluxed ammonia-containing steam undergo heat exchange reaction in the packing area, so that the wastewater temperature is further increased to 80-90°C; the sludge brought into the wastewater and the sludge generated during the analysis reaction are regularly discharged to the concentrated residue precipitation tank through a pump; the effluent of the analysis reaction tower is lifted by a pump to the deammoniation unit.

[0030] A deamination unit is connected to the analytical unit, and the deamination unit comprises a deamination tower 4 and a water pump; a packing area is provided at the top of the deamination tower, and a water collection area is provided at the bottom; saturated steam is introduced into the deamination tower, and the deamination tower is controlled to be in a negative pressure state by a negative pressure device; the ammonia-containing wastewater entering the deamination tower and the added steam undergo a stripping deamination reaction in the packing area, and the ammonia-containing steam at the top flows back to the analytical reaction tower of the analytical unit; the wastewater at the bottom is pumped to the preheater 2 of the analytical unit;

[0031] The ammonia absorption unit is connected to the analytical reaction tower 3 of the analytical unit, and the ammonia absorption unit includes a condenser 5, a gas-liquid separator 6, a reflux pump, an ammonia recovery tower 7, a circulating water pump, a cooler 8, an ammonia extraction mixing device 9, a discharge pump, a tail gas recovery and treatment device (tail gas recovery tower 10, tail gas purification tower 11, induced draft fan, etc.); the ammonia recovery tower is provided with a water injection end, a CO 2 The input end, the waste gas input end, the waste gas output end and the liquid discharge end, the input end of the condenser is connected to the steam output end of the analysis unit, the output end of the condenser is connected to the gas-liquid separator, the liquid outlet end of the gas-liquid separator is connected to the deammonification tower of the deammonification unit through a reflux pump, the gas outlet end of the gas-liquid separator is connected to the waste gas input end of the ammonia recovery tower, the waste gas output end of the ammonia recovery tower is connected to the tail gas recovery and treatment device, the liquid discharge end of the ammonia recovery tower 7 is connected to the crystallization dehydration unit through a discharge pump, and the water injection end of the ammonia recovery tower is connected to the liquid reflux end of the crystallization dehydration unit; the top of the analysis unit analysis reaction tower 3 After the ammonia-containing steam is condensed by the condenser 5, the ammonia-containing gas is led to the ammonia recovery tower 7 by the ammonia extraction mixing device 9, and the condensate is refluxed to the deammonification tower 4 of the deammonification unit, wherein the ammonia extraction mixing device adopts the Venturi tube principle, and a throat is provided in the ammonia extraction mixing device. The mixed liquid in the ammonia recovery tower is circulated by a water pump, and a cooler and a throat are provided on the circulation pipeline. The throat is connected to the gas outlet end of the condenser at the same time. The mixed liquid enters the throat to form a negative pressure, and the ammonia-containing gas output from the gas outlet end of the condenser is introduced into the ammonia recovery tower 7 by using the Venturi effect; tap water is injected into the ammonia recovery tower 7, and CO is introduced into the ammonia recovery tower 7. 2The circulating water pump draws water from the circulating water outlet at the bottom of the ammonia recovery tower 7 and returns it to the ammonia recovery tower 7 after cooling; ammonia and CO 2 The liquid phase of the ammonia recovery tower 7 reacts to generate ammonium bicarbonate; the non-condensable gas at the top of the ammonia recovery tower enters the tail gas recovery tower 10, is eluted with tap water, and the elution liquid flows back to the ammonia recovery tower 7; the tail gas then enters the purification tower 11, and after acid washing, is led to the biological reaction tank of the sewage treatment system 1 to 3 meters below the aerobic zone; the transitional saturated ammonium bicarbonate solution generated in the ammonia recovery tower 7 is pumped to the crystallization dehydration unit;

[0032] A crystallization and dehydration unit is connected to the ammonia absorption unit; the crystallization and dehydration unit includes a slurry tank 12, a centrifugal dehydrator 13, a mother liquor pool 14, a conveyor 15, a baler 16, a mother liquor pump, etc.; a stirrer is provided in the slurry tank 12. After the ammonium bicarbonate crystals grow and reach a certain concentration, they flow to the centrifugal dehydrator 13 by gravity. The dehydrated filtrate is stored in the mother liquor pool 14 and is pumped to the ammonia recovery tower 7 by the mother liquor pump. The dehydrated ammonium bicarbonate solid is transported to the baler 16 by the conveyor 15.

[0033] The thermal extraction and recovery system of nitrogen resources in the anaerobic fermentation liquid of garbage leachate and kitchen sludge comprises the following steps in sequence:

[0034] (1): Pre-treat the landfill leachate and anaerobic fermentation liquid of food sludge. Fresh leachate (early landfill leachate or incinerator leachate) is pre-treated by anaerobic + sedimentation (or filtration) or anaerobic MBR pre-treatment; aged leachate in landfill is pre-treated by sedimentation or filtration; anaerobic fermentation liquid of food sludge is dehydrated by centrifugation or plate and frame, and the dehydrated filtrate is pre-treated by flotation.

[0035] (2): Preheat the pretreated leachate or biogas slurry to raise its temperature to 55-65°C.

[0036] (3): The preheated leachate or biogas slurry is pumped to the analytical reaction tower, and steam is introduced into the analytical reaction tower. The temperature of the leachate or biogas slurry is further increased to 80-90°C in the analytical reaction tower. After preheating, it enters the upper part of the analytical reaction tower, and the ammonia-containing steam from the deammonification tower enters from the lower part of the analytical reaction tower. During the leachate flowing through the tower plate, it is fully contacted with the reflux ammonia-containing steam and undergoes heat exchange. The leachate temperature further rises, and the bicarbonate ions in the original solution are analyzed into Ions and CO 2 , The ions react with the calcium and magnesium ions in the original solution to generate calcium carbonate and magnesium carbonate precipitates, which are discharged from the analytical reaction tower regularly by the pump. 2Together with the ammonia vapor, it is collected at the top of the analytical reaction tower. After heating and analysis, the proportion of free ammonia nitrogen in the original liquid increases significantly. During the contact reaction with the reflux ammonia vapor, part of the free ammonia in the original liquid diffuses into the gas phase, forming a high concentration of ammonia vapor collected at the top of the analytical reaction tower.

[0037] (4): The effluent from the analytical reaction tower is pumped to the deamination tower, saturated steam is introduced into the deamination tower, and the deamination tower is controlled to be in a negative pressure state through a negative pressure device to achieve steam stripping and deamination.

[0038] (5): The ammonia-containing steam formed in the deammonification tower flows back to the desorption reaction tower, and after heat exchange with the leachate or biogas slurry entering the desorption reaction tower, the ammonia-containing steam at the top of the desorption reaction tower is introduced into the condenser through the ammonia extraction mixing device, and the condensed water flows back to the deammonification tower or the ammonia recovery tower, and the ammonia gas is introduced into the ammonia recovery tower.

[0039] (6): Feed tap water and CO into the ammonia recovery tower 2 , making CO 2 It reacts with ammonia in the liquid phase to generate ammonium bicarbonate and gradually reaches saturation. At the same time, a bypass cooling system is set up to reduce the temperature of the solution in the ammonia recovery tower, so that ammonium bicarbonate crystals are precipitated.

[0040] (7): Regularly discharge the ammonium bicarbonate crystal mixed liquid from the ammonia recovery tower to the crystal slurry tank, cool the mixed liquid in the crystal slurry tank to further precipitate the ammonium bicarbonate, and gravity flow the mixed liquid in the crystal slurry tank to the centrifugal dehydrator for solid-liquid separation. The dehydrated filtrate is returned to the ammonia recovery tower, and the solid is packaged in bags for resource utilization.

[0041] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A nitrogen resource thermal extraction and recovery system, characterized in that: The system comprises: Pretreatment unit: pre-treating the garbage leachate and the anaerobic fermentation liquid of the kitchen sludge to form ammonia-containing wastewater entering the subsequent unit, wherein the COD of the ammonia-containing wastewater is ≤10000mg / L and the SS is ≤1000mg / L; The decomposition unit is connected to the pretreatment unit, and the decomposition unit includes a preheater and a decomposition reaction tower. The upper part of the decomposition reaction tower is provided with a packing area, and the lower part is provided with a water collection area and a sludge hopper. The ammonia-containing wastewater enters the decomposition reaction tower after being preheated. The preheated ammonia-containing wastewater and the ammonia-containing steam refluxed from the deammonification unit undergo a heat exchange reaction in the packing area, so that the temperature of the ammonia-containing wastewater is further increased, and the bicarbonate ions in the ammonia-containing wastewater are decomposed into ions and CO2, ions react with calcium and magnesium ions in the ammonia-containing wastewater to generate carbonate precipitates, and CO2 is collected together with the ammonia-containing steam at the top of the analytical reaction tower and transported to the ammonia absorption unit through the top of the analytical reaction tower; the ammonia-containing wastewater in the analytical reaction tower is lifted to the deammoniation unit by a water pump; A deamination unit connected to the analytical unit, the deamination unit comprising a deamination tower and a water pump; a packing area is provided at the top of the deamination tower, a water collection area is provided at the bottom, an external steam end is provided at the bottom of the packing area of ​​the deamination tower, the steam output port at the top of the deamination tower is connected to the steam reflux end of the analytical reaction tower, and the wastewater input end at the top of the packing area of ​​the deamination tower is connected to the wastewater output end of the analytical reaction tower; after the ammonia-containing wastewater of the analytical reaction tower enters the deamination tower, it undergoes a stripping deamination reaction with the external steam in the packing area, the ammonia nitrogen in the liquid phase enters the vapor phase, the ammonia-containing vapor is collected at the top of the deamination tower, and refluxes from the top of the deamination tower to the analytical reaction tower of the analytical unit; An ammonia absorption unit is connected to the analysis reaction tower of the analysis unit. The ammonia absorption unit includes a condenser, a gas-liquid separator, a reflux pump, an ammonia recovery tower, a circulating water pump, a cooler, an ammonia extraction mixing device, a discharge pump, and a tail gas recovery and treatment device. The ammonia-containing steam at the top of the analysis reaction tower of the analysis unit is condensed by the condenser, and the ammonia-containing gas is led to the ammonia recovery tower, and the condensate is refluxed to the deammonification tower or ammonia recovery tower of the deammonification unit; water is injected into the ammonia recovery tower, and CO2 is introduced into the ammonia recovery tower. The ammonia gas and CO2 in the ammonia-containing gas react in the ammonia recovery tower to generate ammonium bicarbonate solution. The ammonium bicarbonate solution generated in the ammonia recovery tower is discharged by the discharge pump. The ammonia recovery tower is sent to the crystallization and dehydration unit, and the remaining gas in the ammonia recovery tower is sent to the tail gas recovery and treatment device for tail gas treatment. A circulating water outlet is arranged at the bottom of the ammonia recovery tower, and the circulating water outlet is connected back to the upper part of the ammonia recovery tower through a circulating water pump, a cooler and an ammonia extraction mixing device. The ammonia extraction mixing device is also connected to the gas outlet end of the gas-liquid separator to preliminarily cool the gas-liquid mixture in the ammonia recovery tower, and the tap water replenishment amount of the ammonia recovery tower is controlled to make the ammonium bicarbonate solution reach a saturated state. At the same time, a negative pressure environment is formed in the ammonia extraction mixing device, and the gas output from the gas outlet end of the gas-liquid separator is introduced into the gas-liquid mixture of the circulation loop and then enters the ammonia recovery tower; A crystallization dehydration unit is connected to the ammonia absorption unit, and is used to dehydrate the ammonium bicarbonate solution to form ammonium bicarbonate solid, and the dehydrated filtrate is returned to the ammonia recovery tower.

2. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: The pretreatment unit comprises a landfill leachate pretreatment unit and a food sludge anaerobic fermentation biogas slurry pretreatment unit. The landfill leachate pretreatment unit adopts anaerobic + sedimentation or filtration pretreatment or anaerobic MBR pretreatment for fresh leachate from a landfill or leachate from a waste incineration plant, and adopts sedimentation or filtration pretreatment for aged leachate from a landfill. The food sludge anaerobic fermentation biogas slurry pretreatment unit adopts centrifugal or plate and frame dehydration for the food sludge anaerobic fermentation biogas slurry, and adopts flotation pretreatment for the dehydrated filtrate.

3. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: The first input end of the preheater is connected to the balance water tank, and the second input end is connected to the water outlet at the bottom of the deamination tower through a water pump. The first output end of the preheater is connected to the input end of the deamination reaction tower, and the second output end is connected to the water outlet pipe. The high-temperature wastewater at the bottom of the deamination tower is pumped to the preheater of the decomposition unit by a water pump, and the ammonia-containing wastewater in the balance water tank flows into the decomposition reaction tower after being preheated.

4. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: The sludge hopper of the analytical reaction tower is connected to the concentrated slag sedimentation tank through a sludge pump. The sludge brought in by the wastewater and the sludge generated during the analytical reaction are collected in the sludge hopper and are regularly discharged to the concentrated slag sedimentation tank through the sludge pump.

5. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: In the ammonia absorption unit, the input end of the condenser is connected to the analysis unit through a pipeline, the output end of the condenser is connected to the gas-liquid separator, the liquid outlet end of the gas-liquid separator is connected to the deammoniation tower of the deammonification unit, and the gas outlet end of the gas-liquid separator is connected to the ammonia recovery tower.

6. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: A gas outlet is arranged at the top of the ammonia recovery tower, and the gas outlet at the top of the ammonia recovery tower is connected to the gas inlet of the tail gas recovery tower. A spray head is arranged at the upper part of the tail gas recovery tower, and the spray head is connected to the water inlet at the upper end of the tail gas recovery tower. A water outlet is arranged at the lower end of the tail gas recovery tower, and the water outlet is connected to the water inlet at the upper end of the ammonia recovery tower through a water pump. The residual gas at the top of the ammonia recovery tower is introduced into the tail gas recovery tower, and is eluted with tap water, and the elution liquid flows back to the ammonia recovery tower.

7. A nitrogen resource thermal extraction and recovery system as claimed in claim 6, characterized in that: A tail gas outlet is arranged on the top of the tail gas recovery tower, and the tail gas outlet is connected to the tail gas purification tower through an induced draft fan. A water inlet is arranged on the upper end of the tail gas purification tower, and pickling liquid is injected into the water inlet of the tail gas purification tower. The top outlet of the tail gas purification tower is connected to the biological reaction tank through the induced draft fan. The tail gas after elution in the tail gas recovery tower is introduced into the tail gas purification tower through the induced draft fan, and after pickling, it is introduced to the aerobic zone of the biological reaction tank of the sewage treatment system 1 to 3m below the liquid.

8. A nitrogen resource thermal extraction and recovery system as claimed in claim 1, characterized in that: The crystallization dehydration unit comprises a slurry tank, in which an agitator is arranged, and the bottom outlet of the slurry tank is connected to a centrifugal dehydrator, which is used to dehydrate the transitional saturated ammonium bicarbonate solution generated by the ammonia recovery tower, and the dehydrated filtrate is stored in a mother liquor pool and pumped to the ammonia recovery tower by the mother liquor pump, and the dehydrated ammonium bicarbonate solid is transported to the baler by a conveyor.

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