Ammonia-nitrogen-containing wastewater treatment method and treatment device

Abstract

The invention provides an ammonia-nitrogen-containing wastewater treatment method and an ammonia-nitrogen-containing wastewater treatment device, relates to the technical field of sewage treatment, and is used for solving the problem of low denitrification efficiency of ammonia-nitrogen wastewater. The treatment method comprises the following steps: introducing ammonia-nitrogen wastewater into a first reaction tank containing activated sludge, and introducing air into the ammonia-nitrogen wastewater to form dissolved oxygen so as to obtain a first treatment solution; the first treatment liquid is introduced into a sedimentation tank for sedimentation treatment, and a sedimentation treatment liquid is obtained; introducing the precipitation treatment liquid into a second reaction tank containing anaerobic ammonia oxidation granular sludge, introducing oxygen into the precipitation treatment liquid while stirring, and carrying out separation treatment to obtain a second treatment liquid containing anaerobic ammonia oxidation granular sludge; the second treatment liquid is introduced into a third reaction tank, anaerobic ammonium oxidation granular sludge in the second treatment liquid is filtered and intercepted through a filler assembly arranged in the third reaction tank, a biological membrane is formed on the filler assembly, anaerobic ammonium oxidation bacteria are loaded on the biological membrane, and third treatment liquid is obtained.

Description

Technical Field

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

[0002] Anaerobic ammonium oxidation process is an important technology in wastewater denitrification, which can directly convert ammonia nitrogen into nitrogen gas to achieve natural nitrogen cycle. Compared with the traditional nitrification / denitrification process, the anaerobic ammonium oxidation process can reduce oxygen consumption, carbon source addition, alkalinity consumption, excess sludge and carbon dioxide production, saving operating costs and floor space.

[0003] The biological reaction process of the anaerobic ammonium oxidation process includes: ① Short-range nitrification: about 53% of ammonia nitrogen is oxidized to nitrite nitrogen by nitrosating bacteria (Ammonia-Oxidizing Bacteria, referred to as AOB), wherein the oxygen consumption of this step is 0.75 molO2 / mol NH4+-N; ② Anaerobic ammonium oxidation: 53% nitrite nitrogen and the remaining 47% ammonia nitrogen are converted into nitrogen gas by anaerobic ammonia-oxidizing bacteria (Anaerobic Ammonia-Oxidizing Bacteria, referred to as AAOB), wherein this step does not require the consumption of oxygen. Denitrification sludge is a specific type of sludge or biological floc formed in the reaction tank in the anaerobic ammonium oxidation process. As an efficient denitrification microorganism in the anaerobic ammonium oxidation process, it has a two-layer structure formed by granular growth. Nitrifying bacteria form a protective film outside the denitrification sludge particles, which can protect the anaerobic ammonium oxidizing bacteria from the influence of oxygen. The nitrosating bacteria consume the oxygen before the oxygen is transferred to the anaerobic ammonium oxidizing bacteria.

[0004] In the related art, the anaerobic ammonium oxidation process includes a one-stage granular sludge anaerobic ammonium oxidation process and a biofilm anaerobic ammonium oxidation process. In the one-stage granular sludge anaerobic ammonium oxidation process, short-range nitritation and anaerobic ammonium oxidation are carried out in the same reaction tank. For low ammonia nitrogen wastewater (NH4+-N≤120mg / L), the wastewater needs to be fully aerated in order to produce sufficient nitrite nitrogen; the biofilm anaerobic ammonium oxidation process installs a packing component in the denitrification reaction tank, and uses the denitrification sludge to form a biofilm on the surface of the packing to treat the wastewater.

[0005] However, the one-stage granular sludge anaerobic ammonium oxidation process for treating low-ammonia nitrogen wastewater has problems such as low denitrification efficiency, poor quality of denitrification granular sludge, high probability of sludge deflocculation and loss, and difficulty in process control and on-site management; the biofilm anaerobic ammonium oxidation process has the problems of low volumetric load (i.e., the ammonia nitrogen load treated per unit volume is small), high cost, and the wastewater treatment derivatives produced are of low value. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a method and device for treating ammonia-nitrogen-containing wastewater, which treats low-ammonia-nitrogen wastewater through a two-stage granular sludge method and anaerobic ammonia oxidation synergistic biofilm method, thereby improving the denitrification efficiency of low-ammonia-nitrogen wastewater and being low-carbon and environmentally friendly.

[0007] Specifically, the present invention proposes the following technical solutions:

[0008] In a first aspect, the present invention provides a method for treating ammonia-nitrogen-containing wastewater, which comprises the following steps:

[0009] Passing ammonia nitrogen wastewater into a first reaction tank containing activated sludge, and passing air into the ammonia nitrogen wastewater to form dissolved oxygen, so as to carry out a decarbonization reaction and a nitrite reaction, and obtain a first treated liquid, wherein the ammonia nitrogen wastewater has an ammonia nitrogen content of ≤120 mg / L; the carbon source in the ammonia nitrogen wastewater is utilized by microorganisms and degraded into carbon dioxide, so as to carry out decarbonization;

[0010] Passing the first treatment liquid into a sedimentation tank for sedimentation treatment to obtain a sedimentation treatment liquid;

[0011] Passing the precipitation treatment liquid into a second reaction tank containing granular sludge, passing oxygen into the precipitation treatment liquid while stirring, so as to carry out anaerobic ammonia oxidation reaction of the granular sludge, and obtaining a second treatment liquid containing granular sludge after separation treatment;

[0012] The second treated liquid is passed into a third reaction tank, and the granular sludge in the second treated liquid is filtered and retained by a filler assembly arranged in the third reaction tank to form a biofilm on the filler assembly, wherein the biofilm carries anaerobic ammonia-oxidizing bacteria to carry out a biofilm anaerobic ammonia-oxidizing reaction to obtain a third treated liquid.

[0013] As a possible implementation manner, the content of dissolved oxygen in the first reaction tank is 1.0-2.0 mg / L, preferably 1.2-1.8 mg / L.

[0014] As a possible implementation manner, the sludge age in the first reaction tank is 2.0-5.0 days, preferably 2.5-4.5 days.

[0015] As a possible implementation manner, the effluent B / C of the first treatment liquid is ≤0.3, preferably B / C ≤0.15, wherein B / C represents the mass ratio of biodegradable organic matter (BOD) to total organic matter (COD) in the wastewater.

[0016] As a possible implementation manner, the effluent of the first treatment liquid has NO2-N≤60mg / L and NO3-N≤10mg / L.

[0017] As a possible implementation manner, in the granular sludge anaerobic ammonia oxidation reaction, the temperature in the second reaction tank is 30-39°C, preferably 33-38°C.

[0018] As a possible implementation manner, the sludge concentration in the second reaction tank is 0.5-15 g / L, preferably 2-10 g / L; preferably, the sludge age is ≥11 days.

[0019] As a possible implementation manner, the sludge load of the granular sludge is 0.1-0.8 kg NH4+-N / (kgVSS.d), preferably 0.2-0.6 kg NH4+-N / (kgVSS.d).

[0020] As a possible implementation manner, the hydraulic retention time in the third reaction tank is 3.0-8.0 h, and the temperature is 30-39° C., preferably 33-38° C.

[0021] As a possible implementation manner, the effluent NH4+-N removal rate of the third treatment liquid is ≥90%, and the TN removal rate is ≥83%.

[0022] As a possible implementation manner, the sludge concentration in the ammonia nitrogen wastewater is 0.5-2 g / L, preferably 0.8-1.5 g / L.

[0023] As a possible embodiment, the temperature of the nitrosation reaction is 26-39° C., preferably 30-38° C., and the reaction pH is further preferably 7.0-8.5, and further preferably 7.4-8.0.

[0024] As a possible implementation, the surface load of the sedimentation tank is ≤0.5m 3 / (m 2 .h), preferably ≤0.4m 3 / (m 2 .h); The suspended solids in the sedimentation tank effluent SS ≤ 200 mg / L, preferably SS ≤ 100 mg / L.

[0025] As a possible implementation mode, in the granular sludge anaerobic ammonia oxidation reaction, the pH of the second treatment liquid is 6.7-8.3, preferably 7.4-8.0; preferably, the concentration of dissolved oxygen formed by introducing oxygen into the precipitation treatment liquid is 0.2-1.0 mg / L, preferably 0.4-0.8 mg / L.

[0026] As a possible implementation manner, the NH4+-N removal rate in the second reaction tank is ≥75%, and the TN removal rate is ≥65%.

[0027] As a possible implementation, in the biofilm anaerobic ammonium oxidation reaction, the pH is 6.7-8.3, preferably 7.4-8.0;

[0028] Preferably, the dissolved oxygen concentration of the reaction liquid is 0.2-1.5 mg / L, preferably 0.5-1.0 mg / L;

[0029] More preferably, the sludge load of the reaction liquid is 0.02-0.4 kg NH4 + -N / (kg VSS.d), preferably 0.15-0.30 kg NH4 + -N / (kg VSS.d);

[0030] Further preferably, the NH4+-N removal rate of the third treatment liquid is ≥60%, and the TN removal rate is ≥50%.

[0031] In a second aspect, the present invention provides an ammonia nitrogen-containing wastewater treatment device, which is used in the treatment method described in any technical solution of the first aspect, and comprises a first reaction tank, a sedimentation tank, a second reaction tank with granular sludge, and a third reaction tank, which are sequentially connected through pipelines, and are used to form the first treatment liquid, the sedimentation treatment liquid, the second treatment liquid, and the third treatment liquid, respectively, and the pipeline is connected to a driving pump for pumping the ammonia nitrogen wastewater;

[0032] The bottom of the first reaction tank, the second reaction tank and the third reaction tank are all provided with an aeration assembly for providing oxygen to the liquid introduced into the first reaction tank, the second reaction tank and the third reaction tank;

[0033] A blocking mechanism is provided between the liquid inlet and the liquid outlet of the sedimentation tank, which is used to intercept the mud in the first treatment liquid to form the sedimentation treatment liquid and guide it to the liquid outlet of the sedimentation tank;

[0034] A packing frame is installed on the side wall of the third reaction tank away from the bottom of the tank. The packing assembly is fixed on the packing frame. The packing assembly includes polyurethane and a biological rope hung on the packing frame. The polyurethane is located on the side of the biological rope away from the bottom of the third reaction tank.

[0035] As a possible implementation, the aeration assembly includes a first aeration duct mounted on the bottom of the first reaction tank and a first aerator disposed on the first perforated aeration duct, and one end of the first aeration duct away from the first aerator is connected to a first blower;

[0036] The aeration assembly further comprises a second aeration duct mounted on the bottom of the second reaction tank and a second aerator disposed on the second aeration duct, wherein one end of the second aeration duct away from the second aerator is connected to a second blower;

[0037] The aeration assembly further comprises a third aeration duct mounted on the bottom of the third reaction tank and a third aerator disposed on the third aeration duct. One end of the third aeration duct away from the third aerator is connected to a third blower.

[0038] As a possible implementation manner, the first aerator, the second aerator and the third aerator are microporous aeration disks or jet aerators.

[0039] As a possible implementation manner, the first reaction tank, the second reaction tank and the third reaction tank are respectively provided with a first water distribution pipe, a second water distribution pipe and a third water distribution pipe, the driving pump includes a first feed pump and a second feed pump, the first feed pump is connected between the water outlet of the sedimentation tank and the water inlet end of the second water distribution pipe, and the second feed pump is connected between the water outlet of the second reaction tank and the water inlet end of the third water distribution pipe.

[0040] As a possible implementation manner, the blocking mechanism includes a plurality of baffles or a plurality of pipes fixed to the side wall of the sedimentation tank, and the baffles or the pipes are arranged at intervals and inclined relative to the bottom wall of the sedimentation tank.

[0041] As a possible implementation, the baffle or the pipe includes a first section and a second section that are connected. In the vertical direction, the first section is parallel to the side wall of the sedimentation tank, and the second section is oblique to the first section and the angle between the second section and the first section is an obtuse angle.

[0042] As a possible implementation manner, a filtering mechanism is provided on the side wall of the second reaction tank near the top side. In the vertical direction, the filtering mechanism is located between the water inlet and the water outlet of the second reaction tank. The filtering mechanism includes a plurality of "herringbone" filter plates arranged in the horizontal direction and an "inverted herringbone" guide hopper located below the filter plate. The filter plate and the guide hopper are both fixed to the side wall of the second reaction tank. The openings of the filter plate and the guide hopper are opposite to each other. The filter plate has a first opening at one end away from the bottom of the tank, and the guide hopper has a second opening at one end close to the bottom of the tank. The filter plate is configured to guide the liquid in the second reaction tank to the water outlet through the first opening under the drive of the third feed pump, intercept and block the granular sludge in the liquid, and discharge it from the second opening along the inner wall of the guide hopper.

[0043] As a possible implementation, the filtering mechanism further includes an overflow groove and a water outlet weir which are connected, the overflow groove is arranged above the filter plate and is connected to the first opening, the water outlet weir is arranged on the side wall of the water outlet and is connected to the water outlet, and the overflow groove is used to drain the liquid filtered by the filter plate to the water outlet weir.

[0044] As a possible implementation, a pressure releaser is provided under the bio-rope, the pressure releaser is fixed to the side wall of the third reaction tank and is connected to the second blower, and the pressure releaser is configured to release airflow toward the biofilm formed on the surface of the bio-rope.

[0045] As a possible implementation, the polyurethane includes hydrophilic polyurethane and / or hydrophobic polyurethane.

[0046] As a possible implementation mode, a sludge hopper is provided at the bottom of the sedimentation tank for collecting, storing and / or discharging sludge in the sedimentation tank; a sludge discharge port is provided on the side wall of the sedimentation tank close to the bottom of the tank, a sludge discharge pipe is passed through the sludge discharge port, one end of the sludge discharge pipe is connected to a sludge discharge pump, and the sludge discharge pump is connected to the first reaction tank, and the sludge discharge pump is configured to discharge the sludge in the sedimentation tank through the sludge discharge pipe, or, to the first reaction tank, so as to regulate the sludge concentration and sludge age in the first reaction tank.

[0047] As a possible implementation manner, the sludge hopper has a conical guide surface, and the end of the sludge discharge pipe opposite to the end connected to the sludge discharge pump extends into the sedimentation tank and is close to the guide surface.

[0048] The present invention has at least the following beneficial effects:

[0049] 1. Treat low-ammonia nitrogen wastewater through two-stage granular sludge anaerobic ammonium oxidation. Perform short-range nitrification and anaerobic ammonium oxidation reactions in two reaction tanks respectively, complete decarbonization and nitrification reactions in the same reaction tank, and enter the granular sludge anaerobic ammonium oxidation reaction tank after mud and water separation in the sedimentation tank to complete the anaerobic ammonium oxidation reaction, effectively avoiding the generation of miscellaneous bacteria in the granular sludge anaerobic ammonium oxidation reaction tank, preventing excessive aeration from causing denitrification sludge deflocculation and loss, improving the quality of granular sludge and reducing the difficulty of control and management of wastewater treatment.

[0050] 2. Granular sludge anaerobic ammonia oxidation method and biofilm method for deep treatment of low ammonia nitrogen wastewater: The effluent from the granular sludge anaerobic ammonia oxidation reaction tank usually carries a small amount of granular sludge due to load shock. The lost granular sludge is intercepted by filler components and a biofilm is formed. The ammonia nitrogen and total nitrogen removal rates of the granular sludge anaerobic ammonia oxidation reaction tank are about 75% and 65%, respectively. There is also unreacted ammonia nitrogen and nitrite nitrogen in the effluent. The use of biofilm for deep denitrification can increase the ammonia nitrogen and total nitrogen removal rates to over 90% and 83%, respectively, and reduce the carbon source addition, oxygen consumption and residual sludge production of the back-end nitrification / denitrification process. The device and method not only have low operating costs, but also significantly improve the shock resistance of granular sludge, thereby improving the denitrification efficiency of wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1This is a schematic diagram of the structure of an ammonia nitrogen-containing wastewater treatment device provided in an embodiment of the present invention.

[0052] Description of reference numerals:

[0053] 1-first reaction tank; 2-first feed pump; 3-first blower;

[0054] 4-first water distribution pipe; 5-first aerator; 6-first aeration air duct;

[0055] 7-water outlet pipe; 8-sludge return pipe;

[0056] 9-sedimentation tank; 10-sedimentation tank water inlet pipe; 11-sludge pump; 12-sludge pipe;

[0057] 13-sludge hopper; 14-baffle; 15-water outlet pipe;

[0058] 16-second reaction tank; 17-second feed pump; 18-second blower;

[0059] 19-second water distribution pipe; 20-second aerator; 21-second aeration air duct;

[0060] 22-perforated aerator; 23-flow guide bucket; 24-filter mechanism;

[0061] 25- overflow trough; 26- outlet weir;

[0062] 27-water outlet pipe; 28-third feed pump;

[0063] 29-third reaction tank; 30-pressure release device;

[0064] 31-third water distribution pipe; 32-third aerator; 33-third aeration air duct;

[0065] 34-filler frame; 35-hydrophilic biological filler; 36-hydrophobic polyurethane; 37-third blower; 38-water outlet pipe. DETAILED DESCRIPTION

[0066] As described in the background technology, the anaerobic ammonium oxidation process plays a key role in the denitrification treatment of wastewater. The related technology adopts a one-stage granular sludge anaerobic ammonium oxidation process to treat low ammonia nitrogen wastewater, which has problems such as low denitrification efficiency, poor quality of denitrification granular sludge, greater risk of sludge deflocculation and loss, and difficulty in process control and on-site management. The biofilm anaerobic ammonium oxidation process has the problems of low volumetric load (i.e., the ammonia nitrogen load treated per unit volume is relatively small), high cost and low value of the wastewater treatment derivatives produced.

[0067] The inventors have found that the reasons for the above problems are: the one-stage anaerobic ammonium oxidation technology aims to oxidize ammonia nitrogen into nitrite nitrogen, which is mainly used for the treatment of high ammonia nitrogen wastewater, and has a low adaptability to the treatment of low ammonia nitrogen wastewater (ammonia nitrogen ≤ 120 mg / L). The nitrogen conversion process of low ammonia nitrogen wastewater requires higher oxygen than high ammonia nitrogen wastewater. The one-stage anaerobic ammonium oxidation technology completes the reaction in a single reaction tank or reaction tank, and its aeration treatment is not controllable enough, which is prone to excessive aeration and excessive oxygen. Oxygen then penetrates the protective film on the surface of the denitrification sludge and enters the sludge particles, causing the sludge to deflocculate and break and gradually lose; on the other hand, it is also prone to insufficient aeration, so that it is impossible to produce enough nitrite nitrogen in the reaction tank, and the denitrification sludge is deposited at the bottom of the reaction tank, resulting in low denitrification efficiency; and in the biofilm anaerobic ammonium oxidation process Since the ammonia nitrogen load treated per unit volume is smaller, it means that a larger reaction tank volume is needed to treat the same amount of wastewater, resulting in an increase in the system's footprint and operating costs. In addition, the investment cost of equipment and infrastructure including membrane materials, reaction tank design and construction, gas supply system, and automation and monitoring system is also larger than other technologies. However, the biofilm method treats wastewater through the biofilm formed by denitrification sludge. Denitrification sludge is usually composed of anaerobic ammonia-oxidizing bacteria, which operate under low-oxygen or anaerobic conditions. The main components of denitrification sludge are nitrite nitrogen and nitrate nitrogen, as well as organic matter related to cell growth and metabolism. Unlike the aerated sludge formed in the reaction tank by the granular sludge method, it does not contain organic matter and nutrients, cannot be used to make fertilizers or other agricultural products, and lacks commercial value.

[0068] In addition, the inventors' research has also found that in the relevant technologies, the reaction tanks for anaerobic ammonia oxidation denitrification by the granular sludge method and the biofilm method are all integrated structures, that is, the integrated design of the granular sludge reaction zone, the biological filler reaction zone and the separation and sedimentation zone in the reaction tank not only cannot effectively decarbonize the wastewater, but also for wastewater containing organic matter, it is easy to produce a large number of miscellaneous bacteria in the reaction tank, thereby reducing the bacterial quality and denitrification efficiency of the denitrification sludge.

[0069] In view of the above technical problems, the embodiments of the present invention provide a method and a treatment device for treating wastewater containing ammonia nitrogen, which deeply treats low ammonia nitrogen wastewater through two-stage granular sludge anaerobic ammonia oxidation and biofilm method. The system consists of four units: synchronous decarbonization and nitrification reaction tank, sedimentation tank, granular sludge anaerobic ammonia oxidation reaction tank, and biofilm anaerobic ammonia oxidation reaction tank. The deep treatment of low ammonia nitrogen wastewater is achieved through decarbonization, nitrification, anaerobic ammonia oxidation and deep denitrification, which solves the shortcomings of the prior art. The related technology described in the present invention is suitable for deep denitrification of wastewater containing organic matter and different concentrations of ammonia nitrogen, and has the advantages of high denitrification efficiency, good granular sludge quality, low control and management difficulty, strong impact ability, and low operating cost.

[0070] The present invention is described in detail below through specific examples, and the manufacturers of the raw materials and equipment used in the present examples, as well as the equipment and analysis methods used for product analysis are described as follows. Among them, the technology of the present invention does not involve non-food raw materials, and the information of the raw materials used in the examples is shown in Table 1.

[0071] The following is an explanation of the technical terms involved in the embodiments:

[0072] Anaerobic ammonium oxidation process: a biological treatment process used in the field of nitrogen removal, which can directly convert ammonia nitrogen into nitrogen gas. It is a part of the natural nitrogen cycle. The biological reaction process is divided into two steps: ① Short-range nitrite: nitrite bacteria (AOB) oxidize about 53% of ammonia nitrogen into nitrite nitrogen. The oxygen consumption in this step is 0.75 molO2 / mol NH4+-N; ② Anaerobic ammonium oxidation: anaerobic ammonium oxidizing bacteria (AAOB) convert 53% of nitrite nitrogen and the remaining 47% of ammonia nitrogen into nitrogen gas. This step does not require oxygen consumption.

[0073] Denitrification granular sludge: granular denitrification sludge aggregates formed in the process of denitrification bacteria using ammonia as electron donor, oxidizing ammonia into nitrogen gas through anaerobic ammonium oxidation, using nitrate or nitrite as electron acceptor.

[0074] Table 1 Raw materials and process equipment used in the examples

[0075]

[0076]

[0077] Table 2 Example index detection method

[0078]

[0079] Table 3 Parameter calculation method of the embodiment

[0080]

[0081]

[0082] In the first aspect, an embodiment of the present invention provides a method for treating ammonia-nitrogen-containing wastewater, which is illustrated by the following embodiments, wherein the synchronous decarbonization and nitrification reaction tank is the first reaction tank, the granular sludge anaerobic ammonia oxidation reaction tank is the second reaction tank, and the biofilm anaerobic ammonia oxidation reaction tank is the third reaction tank. The index detection method in the embodiment is shown in Table 2, and the parameter calculation method is shown in Table 3.

[0083] Example 1

[0084] 1.1. One-stage granular sludge anaerobic ammonium oxidation process test

[0085] Low ammonia nitrogen wastewater (ammonia nitrogen 102mg / L, total nitrogen 113mg / L) is pumped into a 16m long, 14m wide, 8m high, effective water depth 7.2m, effective volume 1612m 3 The synchronous decarbonization and nitrification reaction tank is a reinforced concrete rectangular structure with a microporous aeration plate installed at the bottom.

[0086] The dissolved oxygen in the reaction tank is 0.7 mg / L, the sludge age is 2.5 days, the activated sludge concentration is 1.1 g / L, the temperature is 38 ° C, the pH is 7.8, the effluent B / C is 0.20, the TN concentration is 113 mg / L, the NO2-N (nitrite nitrogen) concentration is 0.8 mg / L, and the NO3-N (nitrate nitrogen) concentration is 0.1 mg / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank of the reinforced concrete structure by gravity, the hydraulic retention time is 4 hours, and the surface load of the sedimentation module is 0.38m 3 / (m 2 .h), the suspended solids (SS) in the sedimentation tank effluent is 95mg / L. The effluent from the sedimentation tank is pumped to a reservoir with a diameter of 8m, a height of 8m, an effective water depth of 7.2m, and an effective volume of 1447m 3 The granular sludge anaerobic ammonia oxidation reaction tank has a cylindrical structure and is made of carbon steel, and the reaction tank has good anti-corrosion performance.

[0087] A microporous aeration plate and a perforated aeration pipe are installed at the bottom of the reaction tank, and a perforated water distribution pipe is installed above the aeration plate. In this way, the microporous aeration plate, the perforated aeration pipe and the perforated water distribution pipe can play a good airflow and hydraulic stirring role on the granular sludge formed at the bottom of the reaction tank, thereby preventing uneven mass transfer and mixing of the granular sludge.

[0088] In this embodiment, the sludge load in the reaction tank is 0.35kgNH4+-N / (kgVSS.d), which represents the mass of ammonia nitrogen (NH4+-N) consumed by unit VSS mass per unit time, wherein VSS is volatile suspended solids; the dissolved oxygen is 1.0mg / L, the denitrification granular sludge concentration (VSS) is 5g / L, the temperature is 38°C, the pH is 7.8, the sludge age is 20d, the effluent ammonia nitrogen concentration is 38mg / L, the total nitrogen concentration is 51mg / L, the ammonia nitrogen removal rate is 63%, and the total nitrogen removal rate is 55%.

[0089] 1.2. Two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm process for deep treatment of low ammonia nitrogen wastewater:

[0090] Low ammonia nitrogen wastewater (ammonia nitrogen concentration of 112 mg / L, total nitrogen concentration of 119 mg / L) is pumped into a 16m long, 14m wide and 8m high water reservoir with an effective water depth of 7.2m and an effective volume of 1612m 3 The synchronous decarbonization and nitrification reaction tank is a reinforced concrete rectangular structure. A microporous aeration plate is installed at the bottom of the reaction tank. The dissolved oxygen in the tank is 1.5 mg / L, the sludge age is 4 days, the activated sludge concentration is 1.2 g / L, the temperature is 38°C, the pH is 7.8, and the effluent B / C is 0.14, where B / C represents the mass ratio of biodegradable organic matter (BOD) in the wastewater to the total organic matter (COD). The units of BOD and COD are both mg / L, and the BOD5 / COD index is the ratio of 5-day biochemical oxygen demand to chemical oxygen demand; the NO2-N concentration is 49 mg / L, and the NO3-N concentration is 4.8 mg / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank of the reinforced concrete structure by gravity. The hydraulic retention time is 4 hours, and the surface load of the sedimentation tank is 0.38m 3 / (m 2 .h), the SS of sedimentation tank effluent is 80mg / L.

[0091] It should be noted that the pH value is regulated by a pipeline connected to the first reaction tank and passing through an alkaline solution, the alkaline solution includes sodium hydroxide and / or sodium bicarbonate, and the incoming water exchanges heat with a cold source or a heat source through a heat exchanger to control the temperature of the reaction tank.

[0092] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, an effective water depth of 7.2m and an effective volume of 1447m 3 The granular sludge anaerobic ammonia oxidation reaction tank is a carbon steel anti-corrosion cylindrical structure. Microporous aeration plates and perforated aeration pipes are installed at the bottom of the reaction tank, and perforated water pipes are installed on the aeration plates. The microporous aeration plates, perforated aeration pipes and perforated water pipes can form good airflow and hydraulic stirring for the granular sludge at the bottom of the reaction tank to prevent uneven mass transfer and mixing of the granular sludge. The sludge load in the reaction tank is 0.4kgNH4+-N / (kgVSS.d), dissolved oxygen is 0.5mg / L, the concentration of denitrified granular sludge (VSS) is 5.2g / L, and the temperature in the reaction tank is 38℃. The temperature of the reaction tank can be controlled by heat exchange with a cold source or a heat source through a heat exchanger. The temperature in the first reaction tank is the same as that in the second reaction tank, pH is 7.8, the sludge age is 20d, and the effluent ammonia nitrogen in the granular sludge anaerobic ammonia oxidation reaction tank is 27mg / L, the total nitrogen is 35mg / L, the ammonia nitrogen removal rate is 76%, and the total nitrogen removal rate is 71%.

[0093] It should be noted that according to the sludge concentration detected in the second reaction tank and the total nitrogen concentration of the influent, the sludge load control can be achieved by adjusting the influent flow rate. The calculation formula of the sludge load is C TN *Q*24 / (VSS*V 第二反应池) Among them, C TN : total nitrogen concentration in influent, mg / L; Q: influent flow rate, m 3 / h; VSS: sludge concentration detected in the second reaction tank, mg / L; V 第二反应池 : Effective volume of the second reaction tank, m 3 .

[0094] The effluent from the granular sludge anaerobic ammonia oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, 7.2m effective water depth, and 1612m effective volume. 3 The biofilm anaerobic ammonia oxidation reaction tank is a reinforced concrete rectangular structure. A cyclone water distribution pipe and a microporous aeration plate are installed at the bottom of the reaction tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts 0.3% of the granular sludge by volume in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to release the pressure inside the reaction tank to ensure that there is no unnecessary high pressure in the reaction tank. The filler surface can also be regularly purged to avoid the formation of an anaerobic environment due to the excessive density of the biofilm layer, which helps to maintain good biological reaction conditions and improve the efficiency of wastewater treatment.

[0095] The hydraulic retention time in the reaction tank is 5h, the dissolved oxygen concentration is 0.8mg / L, the temperature is 38℃, the pH is 7.7, the sludge age is 20d, the sludge load is 0.2kgNH4+-N / (kgVSS.d), the effluent ammonia nitrogen in the biofilm anaerobic ammonia oxidation reaction tank is 9mg / L, the total nitrogen is 17mg / L, the NH4+-N removal rate is 66%, and the TN removal rate is 51%.

[0096] The biofilm anaerobic ammonia oxidation reaction tank is connected with an alkali solution pipeline, and an alkali delivery pump is arranged on the alkali solution pipeline. The alkali solution is sodium hydroxide or sodium bicarbonate solution. In this way, alkali solution can be added to the third reaction tank to compensate for the decrease in alkalinity of the liquid in the tank caused by the biofilm anaerobic ammonia oxidation reaction, which provides a guarantee for the reaction kinetics to ensure the wastewater treatment efficiency.

[0097] 1.3. Technical evaluation: The two-stage granular sludge anaerobic ammonium oxidation synergistic biofilm process can deeply treat low-ammonia nitrogen wastewater (ammonia nitrogen 112mg / L, total nitrogen 119mg / L), with an NH4+-N removal rate of 92% and a TN removal rate of 86%, which is better than the one-stage granular sludge anaerobic ammonium oxidation process with an NH4+-N removal rate of 63% and a TN removal rate of 55%. Moreover, by calculation, the carbon source is reduced by 0.36kg / m 3 , power consumption saved 0.142KWh / m 3The aerobic sludge production (dry basis, i.e. the mass or volume of solid matter in wastewater sludge or biological sludge, excluding the water content) decreased by 0.146 kg / m 3 .

[0098] For example, the sedimentation tank used in this embodiment may be in the shape of a rectangular parallelepiped structure, which is convenient for manufacturing, processing and maintenance.

[0099] Theoretical calculation process description: Two-stage two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm total nitrogen removal rate is 86%, one-stage granular sludge anaerobic ammonia oxidation total nitrogen removal rate is 55%, the influent is 119 mg / L, about 119*(86%-55%)=36.55 mg / L total nitrogen enters the back-end AO system for treatment. Under normal circumstances, the COD:TN of the AO system is 10:1, and 365.5 mg / L of COD (carbon source) and 0.3655 kg / m of carbon source need to be supplemented. 3 ; The oxygen consumption of 36.55mg / L total nitrogen is 36.55*4.57=167mg / L, the oxygen consumption of 365.5mg / L COD is 365.5*1=365.5mg / L, the total oxygen consumption is 167+365.5=532.5mg / L=532.5g / m3, ignoring the influence of water temperature, the oxygen content in the air is 21%, the dissolved oxygen efficiency of the aeration system is 25%, then the required air volume is 532.5 / 21% / 25% / 32*22.4 / 1000=7.1m 3 Air / m 3 Wastewater, taking the magnetic levitation fan as an example, the water depth is 7.2m 3 , air volume 2500m 3 / h, operating power 50KW, power saving 7.1*50 / 2500=0.142KWh / m 3 The output of residual sludge is about 40% of the total COD removed, that is, 365.5*40% / 1000=0.146kg / m 3 .

[0100] Example 2

[0101] Low ammonia nitrogen wastewater (ammonia nitrogen 108mg / L, total nitrogen 119mg / L) is pumped into a 16m long, 14m wide, 8m high, and effective volume of 1612m 3The synchronous decarbonization and nitrification reaction tank of reinforced concrete rectangular structure has a microporous aeration plate installed at the bottom. The dissolved oxygen in the reaction tank is 1.0 mg / L, the sludge age is 2.0 days, the effluent B / C is 0.15, the TN concentration is 117 mg / L, the NO2-N concentration is 37 mg / L, the NO3-N concentration is 0.5 mg / L, and the sludge concentration is 1.5 g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the reinforced concrete structure sedimentation tank by gravity. The surface load of the sedimentation module is 0.38m 3 / (m 2 .h), sedimentation tank effluent SS 75mg / L.

[0102] It should be noted that dissolved oxygen is controlled by adjusting the operating frequency parameters of the first aeration fan and the air supply, and is detected by an online dissolved oxygen meter installed in the reaction tank; sludge age is controlled by adjusting the sludge discharge flow rate of the sedimentation tank, and the sludge discharge flow rate corresponding to the sludge age is calculated using the formula in Table 3 of the sludge age. By controlling the main parameters of dissolved oxygen and sludge age in the first reaction tank, and auxiliary control of parameters including wastewater pH value, temperature and sludge load, the effluent B / C, NO2-N and NO3-N can be controlled within the special ranges defined in this application.

[0103] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, and an effective volume of 1447m 3 The granular sludge anaerobic ammonia oxidation reaction tank with carbon steel anti-corrosion structure, the microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form a good airflow and hydraulic stirring for the granular sludge at the bottom of the reaction tank, avoiding uneven mass transfer and mixing of granular sludge. The sludge load in the reaction tank is 0.1kgNH4+-N / (kgVSS.d), dissolved oxygen is 0.2mg / L, effluent ammonia nitrogen is 27mg / L, total nitrogen is 42mg / L, sludge concentration is 10g / L, sludge age is 11 days, ammonia nitrogen removal rate is 75%, and total nitrogen removal rate is 65%.

[0104] It should be noted that the calculation formula for the sludge load in the reaction tank is: influent TN concentration * influent flow rate per hour * 24 / (sludge concentration * effective volume of the reaction tank body). The sludge concentration is relatively stable over a certain period of time. According to the detected influent TN concentration, the influent flow rate per hour is adjusted to control it. The control method of dissolved oxygen is the same as that of the first reaction tank, and the formula method used in the following embodiments is the same. The effluent ammonia nitrogen and total nitrogen are detected by online monitoring instruments for ammonia nitrogen and total nitrogen or by manual sampling.

[0105] Ammonia nitrogen removal rate = (ammonia nitrogen concentration in the inlet of the first reaction tank - ammonia nitrogen concentration in the outlet of the second reaction tank) / ammonia nitrogen concentration in the inlet of the first reaction tank * 100% = (108-27) / 108 * 100% = 75%. In order to facilitate the comparison with the ammonia nitrogen removal efficiency of the one-stage granular sludge anaerobic ammonia oxidation process, the inlet ammonia nitrogen of the ammonia nitrogen removal rate of the second reaction tank is based on the inlet ammonia nitrogen concentration of the first reaction tank. The total nitrogen concentration of the inlet and outlet of the first reaction tank changes little, indicating that the first reaction tank and the sedimentation tank have no effect on the removal of total nitrogen. Based on this, it is reasonable to use the inlet ammonia nitrogen of the ammonia nitrogen removal rate of the second reaction tank based on the inlet ammonia nitrogen concentration of the first reaction tank.

[0106] Total nitrogen removal rate = (total nitrogen concentration of the inlet water of the first reaction tank - total nitrogen concentration of the effluent water of the second reaction tank) / total nitrogen concentration of the inlet water of the first reaction tank * 100% = (119-42) / 119 * 100% = 65%. The calculation method of the second reaction tank is the same.

[0107] The effluent from the granular sludge anaerobic ammonium oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank has a cyclone water distribution pipe and a microporous aeration plate installed at the bottom of the tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biological rope. The hydraulic retention time of the reaction tank is 3h, the effluent ammonia nitrogen is 11mg / L, the total nitrogen is 20mg / L, the ammonia nitrogen removal rate is 61%, and the total nitrogen removal rate is 53%.

[0108] It should be noted that the hydraulic retention time of the third reaction tank = effective water volume of the reaction tank body / hourly water inlet flow rate. The effective water volume of the reaction tank body is a constant. The hydraulic retention time is controlled by adjusting the hourly water inlet flow rate. The longer the hydraulic retention time, the relatively higher the removal efficiency. Due to the consumption of the substrate matrix, the hydraulic retention time is too long and the removal efficiency cannot be further improved.

[0109] The ammonia nitrogen removal rate of the third reaction tank = (ammonia nitrogen concentration of the inlet water of the third reaction tank - ammonia nitrogen concentration of the effluent water of the third reaction tank) / ammonia nitrogen concentration of the inlet water of the third reaction tank * 100% = (27-11) / 27*100% = 61%, the total nitrogen removal rate = (total nitrogen concentration of the inlet water of the third reaction tank - total nitrogen concentration of the effluent water of the third reaction tank) / total nitrogen concentration of the inlet water of the third reaction tank * 100% = (42-20) / 42*100% = 53%, the calculation method of the third reaction tank in the following embodiments is the same.

[0110] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 102 mg / L, total nitrogen 113 mg / L), with a total NH4+-N removal rate of 90% and a total TN removal rate of 84%.

[0111] It should be noted that the ammonia nitrogen removal rate of the two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method = (ammonia nitrogen concentration of the influent of the first reaction tank - ammonia nitrogen concentration of the effluent of the third reaction tank) / ammonia nitrogen concentration of the influent of the first reaction tank * 100% = (108-11) / 108*100% = 90%, the total nitrogen removal rate = (total nitrogen concentration of the influent of the first reaction tank - total nitrogen concentration of the effluent of the third reaction tank) / total nitrogen concentration of the influent of the first reaction tank * 100% = (119-20) / 119*100% = 84%, and the calculation method of the third reaction tank below is the same.

[0112] It should be noted that the temperature in the second and third reaction tanks was controlled at 35°C.

[0113] Example 3

[0114] Low ammonia nitrogen wastewater (ammonia nitrogen 113mg / L, total nitrogen 123mg / L) is pumped into a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The synchronous decarbonization and nitrification reaction tank of reinforced concrete rectangular structure has a microporous aeration plate installed at the bottom. The dissolved oxygen in the reaction tank is 1.2mg / L, the sludge age is 2.5d, the effluent B / C is 0.15, the TN concentration is 121mg / L, the NO2-N concentration is 53mg / L, the NO3-N concentration is 1.2mg / L, and the sludge concentration is 2g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the reinforced concrete structure sedimentation tank by gravity. The surface load of the sedimentation module is 0.38m 3 / h / m 2 , SS of sedimentation tank effluent is 75mg / L.

[0115] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, and an effective volume of 1447m 3 Granular sludge anaerobic ammonia oxidation reaction tank with carbon steel anti-corrosion structure. The microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form good airflow and hydraulic stirring for the granular sludge at the bottom of the reaction tank, avoiding uneven mass transfer and mixing of granular sludge. The sludge load in the reaction tank is 0.2kgNH4+-N / (kgVSS.d), dissolved oxygen is 0.5mg / L, effluent ammonia nitrogen is 26mg / L, total nitrogen is 38mg / L, sludge concentration is 0.5g / L, sludge age is 15 days, ammonia nitrogen removal rate is 77%, and total nitrogen removal rate is 69%.

[0116] The effluent from the granular sludge anaerobic ammonium oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, and effective volume of 1612m 3The reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank has a cyclone water distribution pipe and a microporous aeration plate installed at the bottom of the tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biological rope. The hydraulic retention time of the reaction tank is 4h, the effluent ammonia nitrogen is 9mg / L, the total nitrogen is 16mg / L, the ammonia nitrogen removal rate is 66%, and the total nitrogen removal rate is 58%.

[0117] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 113 mg / L, total nitrogen 123 mg / L), with a total NH4+-N removal rate of 92% and a total TN removal rate of 87%.

[0118] It should be noted that the temperature in the second and third reaction tanks was controlled at 39°C.

[0119] Example 4

[0120] Low ammonia nitrogen wastewater (ammonia nitrogen 120mg / L, total nitrogen 128mg / L) is pumped into a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The synchronous decarbonization and nitrification reaction tank is a reinforced concrete rectangular parallelepiped structure. A microporous aeration plate is installed at the bottom. The dissolved oxygen in the reaction tank is 2.0 mg / L, the sludge age is 5.0 days, the effluent B / C is 0.10, the TN concentration is 125 mg / L, the NO2-N concentration is 56 mg / L, the NO3-N concentration is 9.6 mg / L, and the sludge concentration is 0.5 g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank by gravity. The sedimentation tank is a reinforced concrete structure, and the surface load of the sedimentation module is 0.38m 3 / h / m 2 , SS of sedimentation tank effluent is 85mg / L.

[0121] The effluent from the sedimentation tank is pumped to the granular sludge anaerobic ammonia oxidation reaction tank with a carbon steel anti-corrosion structure of 8m in diameter, 8m in height and an effective volume of 1447m3. The microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form a good airflow and hydraulic agitation for the granular sludge at the bottom of the reaction tank to avoid uneven mass transfer and mixing of the granular sludge. The sludge load in the reaction tank is 0.8kgNH4+-N / (kgVSS.d), dissolved oxygen is 1.0mg / L, effluent ammonia nitrogen is 26mg / L, total nitrogen is 45mg / L, sludge concentration is 2g / L, sludge age is 13 days, ammonia nitrogen removal rate is 78%, and total nitrogen removal rate is 65%.

[0122] The effluent from the granular sludge anaerobic ammonium oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank has a cyclone water distribution pipe and a microporous aeration plate installed at the bottom of the tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biological rope. The hydraulic retention time of the reaction tank is 6h, the effluent ammonia nitrogen is 10mg / L, the total nitrogen is 22mg / L, the ammonia nitrogen removal rate is 63%, and the total nitrogen removal rate is 50%.

[0123] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 120 mg / L, total nitrogen 128 mg / L), with a total NH4+-N removal rate of 92% and a total TN removal rate of 83%.

[0124] It should be noted that the temperature in the second and third reaction tanks was controlled at 30°C.

[0125] Example 5

[0126] Low ammonia nitrogen wastewater (ammonia nitrogen 92mg / L, total nitrogen 104mg / L) is pumped into a synchronous decarbonization and nitrification reaction tank with a length of 16m, a width of 14m, a height of 8m, and an effective volume of 1612m3. A microporous aeration plate is installed at the bottom. The dissolved oxygen in the reaction tank is 1.8mg / L, the sludge age is 4.5d, the effluent B / C=0.10, the TN concentration is 104mg / L, the NO2-N concentration is 47mg / L, the NO3-N concentration is 3.4mg / L, and the sludge concentration is 0.8g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank by gravity. The sedimentation tank is a reinforced concrete structure, and the surface load of the sedimentation module is 0.38m 3 / (m 2 .h), sedimentation tank effluent SS 80mg / L.

[0127] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, and an effective volume of 1447m 3Granular sludge anaerobic ammonia oxidation reaction tank with carbon steel anti-corrosion structure. The microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form a good airflow and hydraulic stirring for the granular sludge at the bottom of the reaction tank, avoiding uneven mass transfer and mixing of granular sludge. The sludge load in the reaction tank is 0.6kgNH4+-N / (kgVSS.d), dissolved oxygen is 0.8mg / L, effluent ammonia nitrogen is 18mg / L, total nitrogen is 25mg / L, sludge concentration is 0.5g / L, sludge age is 13 days, ammonia nitrogen removal rate is 80%, and total nitrogen removal rate is 71%.

[0128] The effluent from the granular sludge anaerobic ammonium oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank has a cyclone water distribution pipe and a microporous aeration plate installed at the bottom of the tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biological rope. The hydraulic retention time of the reaction tank is 5h, the effluent ammonia nitrogen is 5mg / L, the total nitrogen is 11mg / L, the ammonia nitrogen removal rate is 72%, and the total nitrogen removal rate is 58%.

[0129] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 92 mg / L, total nitrogen 104 mg / L), with a total NH4+-N removal rate of 94% and a total TN removal rate of 90%.

[0130] It should be noted that the temperature in the second and third reaction tanks was controlled at 38°C.

[0131] Example 6

[0132] Low ammonia nitrogen wastewater (ammonia nitrogen 105mg / L, total nitrogen 109mg / L) is pumped into a synchronous decarbonization and nitrification reaction tank with a length of 16m, a width of 14m, a height of 8m, and an effective volume of 1612m3. A microporous aeration plate is installed at the bottom. The dissolved oxygen in the reaction tank is 0.5mg / L, the sludge age is 1.7d, the effluent B / C=0.3, the TN concentration is 109mg / L, the NO2-N concentration is 2.5mg / L, the NO3-N concentration is 0.1mg / L, and the sludge concentration is 1g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank by gravity. The sedimentation tank is a reinforced concrete structure, and the surface load of the sedimentation module is 0.38m 3 / (m 2 .h), sedimentation tank effluent SS150mg / L.

[0133] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, and an effective volume of 1447m 3 Granular sludge anaerobic ammonia oxidation reaction tank with carbon steel anti-corrosion structure. The microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form good airflow and hydraulic stirring for the granular sludge at the bottom of the reaction tank, avoiding uneven mass transfer and mixing of granular sludge. The sludge load in the reaction tank is 0.06kgNH4+-N / (kgVSS.d), dissolved oxygen is 0.15mg / L, effluent ammonia nitrogen is 81mg / L, total nitrogen is 93mg / L, sludge concentration is 12g / L, sludge age is 11 days, ammonia nitrogen removal rate is 23%, and total nitrogen removal rate is 15%.

[0134] The effluent of the granular sludge anaerobic ammonia oxidation reaction tank is pumped from the bottom to the reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank with a length of 16m, a width of 14m, a height of 8m, and an effective volume of 1612m3. The bottom of the tank is equipped with a cyclone water distribution pipe and a microporous aeration plate. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biorope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biorope. The hydraulic retention time of the reaction tank is 2h, the effluent ammonia nitrogen is 65mg / L, the total nitrogen is 80mg / L, the ammonia nitrogen removal rate is 20%, and the total nitrogen removal rate is 14%.

[0135] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 105 mg / L, total nitrogen 109 mg / L), with a total NH4+-N removal rate of 38% and a total TN removal rate of 27%.

[0136] It should be noted that the temperature in the second and third reaction tanks was controlled at 33°C.

[0137] Example 7

[0138] Low ammonia nitrogen wastewater (ammonia nitrogen 116mg / L, total nitrogen 124mg / L) is pumped into a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The synchronous decarbonization and nitrification reaction tank is a reinforced concrete rectangular parallelepiped structure. A microporous aeration plate is installed at the bottom. The dissolved oxygen in the reaction tank is 2.5 mg / L, the sludge age is 6.0 days, the effluent B / C is 0.10, the TN concentration is 122 mg / L, the NO2-N concentration is 35 mg / L, the NO3-N concentration is 38 mg / L, and the sludge concentration is 1 g / L. The mud-water mixture of the synchronous decarbonization and nitrification reaction tank flows into the sedimentation tank by gravity. The sedimentation tank is a reinforced concrete structure, and the surface load of the sedimentation module is 0.38m 3 / (m 2.h), sedimentation tank effluent SS 50mg / L.

[0139] The effluent from the sedimentation tank is pumped to a tank with a diameter of 8m, a height of 8m, and an effective volume of 1447m 3 The granular sludge anaerobic ammonia oxidation reaction tank is made of carbon steel anti-corrosion structure. The microporous aeration plate, perforated aeration pipe and perforated water pipe installed at the bottom of the reaction tank can form a good airflow and hydraulic agitation for the granular sludge at the bottom of the reaction tank, avoiding uneven mass transfer and mixing of the granular sludge. The sludge load in the reaction tank is 0.9kgNH4+-N / (kgVSS.d), dissolved oxygen is 1.2mg / L, effluent ammonia nitrogen is 17mg / L, total nitrogen is 72mg / L, sludge concentration is 15g / L, sludge age is 13 days, ammonia nitrogen removal rate is 85%, and total nitrogen removal rate is 42%.

[0140] The effluent from the granular sludge anaerobic ammonia oxidation reaction tank is pumped from the bottom to a 16m long, 14m wide, 8m high, and effective volume of 1612m 3 The reinforced concrete structure of the biofilm anaerobic ammonia oxidation reaction tank has a cyclone water distribution pipe and a microporous aeration plate installed at the bottom of the tank. The hydrophobic polyurethane and the biological rope are fixed on the 316L stainless steel fixed filler assembly in the middle of the reaction tank. The hydrophobic polyurethane intercepts the granular sludge with a volume ratio of 0.3% in the effluent of the granular sludge anaerobic ammonia oxidation reaction tank. The granular sludge gradually forms a biofilm on the surface of the biological rope. A pressure releaser is installed at the bottom of the fixed filler assembly to regularly backwash the biofilm on the surface of the biological rope. The hydraulic retention time of the reaction tank is 7h, the effluent ammonia nitrogen is 9mg / L, the total nitrogen is 55mg / L, the ammonia nitrogen removal rate is 47%, and the total nitrogen removal rate is 22%.

[0141] It should be noted that the temperature in the second and third reaction tanks was controlled at 35°C.

[0142] The two-stage granular sludge anaerobic ammonia oxidation synergistic biofilm method can deeply treat low ammonia nitrogen wastewater (ammonia nitrogen 116 mg / L, total nitrogen 124 mg / L), with a total NH4+-N removal rate of 92% and a total TN removal rate of 55%.

[0143] In a second aspect, an embodiment of the present invention provides an ammonia nitrogen-containing wastewater treatment device for use in the wastewater treatment method provided in any embodiment of the first aspect, with reference to Figure 1, which comprises a first reaction tank 1, a sedimentation tank 9, a second reaction tank 16 with granular sludge and a third reaction tank 29 which are sequentially connected by pipelines, and are used to form a first treatment liquid, a sedimentation treatment liquid, a second treatment liquid and a third treatment liquid respectively. A driving pump is connected to the pipeline for pumping ammonia nitrogen wastewater. A water inlet pipe is provided on the side wall of the first reaction tank 1, and the water inlet pipe is connected to a first feed pump 2 to feed external water supply into the first reaction tank. A water outlet is provided on the side wall of the first reaction tank 1 opposite to the water inlet, and an outlet pipe 7 is penetrated through the outlet, which is connected to the water inlet pipe 10 of the sedimentation tank. The sedimentation tank 9 is connected to the second reaction tank 16 through the outlet pipe 15, and the second reaction tank 16 is connected to the third reaction tank 29 through the outlet pipe 27. The effluent from the third reaction tank, i.e., the third treatment liquid, is discharged through the outlet pipe 38;

[0144] The first reaction tank 1, the second reaction tank 16 and the third reaction tank 29 are all provided with an aeration assembly at the bottom thereof, for providing oxygen to the liquid introduced into the first reaction tank 1, the second reaction tank 16 and the third reaction tank 29;

[0145] A blocking mechanism is provided between the liquid inlet and the liquid outlet of the sedimentation tank 9, which is used to intercept the mud in the first treatment liquid to form a sedimentation treatment liquid and guide it to the liquid outlet of the sedimentation tank 9;

[0146] A packing frame 34 is installed on the side wall of the third reaction tank 29 away from the bottom of the tank. The packing assembly is fixed on the packing frame 34. The packing assembly includes polyurethane and a biological rope hung on the packing frame 34. The polyurethane is located on the side of the biological rope away from the bottom of the third reaction tank 29. Exemplarily, the packing assembly includes a hydrophilic biological filler 35 and a hydrophobic polyurethane 36, wherein the hydrophilic biological filler 35 can be a filter rod, annular filter material, sponge filter material or hydrophilic plastic filler.

[0147] As an example, the aeration assembly includes a first aeration duct 6 mounted on the bottom of the first reaction tank 1 and a first aerator 5 disposed on the first perforated aeration duct, and one end of the first aeration duct 6 away from the first aerator 5 is connected to the first blower 3;

[0148] The aeration assembly further includes a second aeration duct 21 mounted on the bottom of the second reaction tank 16 and a second aerator 20 disposed on the second aeration duct 21. One end of the second aeration duct 21 away from the second aerator 20 is connected to a second blower 18.

[0149] The aeration assembly further includes a third aeration duct 33 mounted on the bottom of the third reaction tank 29 and a third aerator 32 disposed on the third aeration duct 33 . One end of the third aeration duct 33 away from the third aerator 32 is connected to a third blower 37 .

[0150] On the basis of the above embodiment, it can be improved that the first aerator 5, the second aerator 20 and the third aerator 32 are microporous aeration disks or jet aerators.

[0151] In another example, the first reaction tank 1, the second reaction tank 16 and the third reaction tank 29 are respectively provided with a first water distribution pipe 4, a second water distribution pipe 19 and a third water distribution pipe 31, and the driving pump includes a second feed pump 17 and a third feed pump 28. The second feed pump 17 is connected between the water outlet of the sedimentation tank 9 and the water inlet end of the second water distribution pipe 19, and the third feed pump 28 is connected between the water outlet of the second reaction tank 16 and the water inlet end of the third water distribution pipe 31.

[0152] In other possible implementations, the blocking mechanism includes a plurality of baffles 14 or a plurality of pipes fixed to the side wall of the sedimentation tank 9 , and the baffles 14 or the pipes are arranged at intervals and inclined relative to the bottom wall of the sedimentation tank 9 .

[0153] On the basis of the above embodiment, it can be improved that the baffle 14 or the pipe includes a connected first section and a second section, and along the vertical direction, the first section is parallel to the side wall of the sedimentation tank 9, and the second section is oblique to the first section and the angle between the second section and the first section is an obtuse angle. In this way, by using the baffle including the oblique first section and the second section, not only can the sludge of the treated liquid leading to the second reaction tank be retained, but the filtered sludge can also be effectively discharged to the lower part of the sedimentation tank through the second section.

[0154] In other examples, a filtering mechanism is provided on the side wall of the second reaction tank near the top side. In the vertical direction, the filtering mechanism is located between the water inlet and the water outlet of the second reaction tank. The filtering mechanism includes a plurality of "herringbone" filter plates arranged in the horizontal direction and an "inverted herringbone" guide hopper located below the filter plate. The filter plate and the guide hopper are both fixed to the side wall of the second reaction tank. The openings of the filter plate and the guide hopper are opposite to each other. The filter plate has a first opening at one end away from the bottom of the tank, and the guide hopper has a second opening at one end close to the bottom of the tank. The filter plate is configured to guide the liquid in the second reaction tank to the outlet through the first opening under the drive of the third feed pump, so as to intercept and block the granular sludge in the liquid and discharge it from the second opening along the inner wall of the guide hopper.

[0155] In this way, the granular sludge before the treated liquid is led to the third reaction tank is intercepted and filtered by the filtering mechanism arranged in the second reaction tank, so as to ensure that the sludge concentration of the effluent entering the third reaction tank is lower than the sludge concentration in the second reaction tank, and improve the denitrification efficiency of the wastewater. Moreover, the filtering mechanism can realize the three-phase separation of wastewater, granular sludge and gas (including air and nitrogen generated by the reaction). The upper filtering mechanism is in a "herringbone" structure, and its main function is to block and intercept granular sludge. Wastewater and gas flow upward from the middle channel of the "herringbone" structure, and granular sludge sinks downward to the guide bucket; the lower guide bucket is in an "inverted herringbone" shape, and its main purpose is to guide the granular sludge intercepted in the effluent to the second reaction tank and block the action of the air below. Furthermore, there are gaps between adjacent "herringbone" structure filter plates, that is, multiple filter plates are arranged at intervals to improve the conveying efficiency of the filtered sludge and impurities into the guide bucket.

[0156] On the basis of the above embodiment, it can be improved that the filtering mechanism also includes an overflow groove and a water outlet weir which are connected to each other, the overflow groove is arranged above the filter plate and is connected to the first opening, the water outlet weir is arranged on the side wall of the water outlet and is connected to the water outlet, and the overflow groove is used to drain the liquid filtered by the filter plate to the water outlet weir, thereby improving the control ability of the water flow.

[0157] In another embodiment, a pressure releaser 30 is provided below the bio-rope. The pressure releaser 30 is fixed to the side wall of the third reaction tank 29 and is connected to the second blower 18. The pressure releaser 30 is configured to release airflow toward the biofilm formed on the surface of the bio-rope.

[0158] As an example, the polyurethane includes hydrophilic polyurethane and / or hydrophobic polyurethane 36 .

[0159] In more possible examples, a sludge hopper 13 is provided at the bottom of the sedimentation tank 9 for collecting, storing, detecting and / or discharging sludge in the sedimentation tank 9, wherein the sludge hopper 13 can detect the sludge concentration and / or temperature; a sludge discharge port is provided on the side wall of the sedimentation tank 9 close to the bottom of the tank, and a sludge discharge pipe 12 is passed through the sludge discharge port, and a sludge discharge pump 11 is connected to one end of the sludge discharge pipe 12, and the sludge discharge pump 11 is connected to the first reaction tank 1. The sludge discharge pump 11 is configured to discharge the sludge in the sedimentation tank 9 through the sludge discharge pipe 12, or, to the first reaction tank 1, so as to regulate the sludge concentration and sludge age in the first reaction tank 1, specifically, the sludge in the sedimentation tank 9 is returned to the first reaction tank 1 through the sludge return pipe 8 connected to the first reaction tank 1.

[0160] Furthermore, the sludge hopper 13 has a conical guide surface, and the end of the sludge discharge pipe 12 opposite to the end connected to the sludge discharge pump 11 extends into the sedimentation tank 9 and is close to the guide surface.

[0161] In another example, a sampling valve is installed on the side wall of the sedimentation tank, and the sludge discharge pipe 12 is connected to a sampler. The sampling valve is used to control the liquid in the sludge discharge pipe 12 to be conducted to the sampler to facilitate the detection of sludge concentration in the sedimentation tank; illustratively, the sludge concentration, temperature and pH of the first reaction tank can be detected by sampling in the tank.

[0162] The ammonia nitrogen-containing wastewater treatment method and treatment device provided by the embodiment of the present invention have at least the following advantages:

[0163] ① Use the synchronous decarbonization and nitrification reaction tank and sedimentation tank to complete the decarbonization and nitrification reaction of low ammonia nitrogen wastewater. By controlling the technical parameters such as sludge concentration, temperature, pH, dissolved oxygen, sludge age, sludge load, surface load, etc., the biodegradable organic matter in the influent is oxidized and decomposed, and the ammonia oxidation is controlled in the nitrification stage. About 50% of ammonia nitrogen is converted into nitrite nitrogen, and a small amount or almost no nitrate nitrogen is produced. The effluent SS is ≤200mg / L. This process can reduce the formation of activated sludge bacteria in the granular sludge anaerobic ammonia oxidation reaction tank and the biofilm anaerobic ammonia oxidation reaction tank, and provide the reaction matrix (50% ammonia nitrogen and 50% nitrite nitrogen) for the granular sludge anaerobic ammonia oxidation reaction tank.

[0164] ② The granular sludge anaerobic ammonia oxidation reaction tank can directly utilize 50% nitrite nitrogen and the remaining 50% ammonia nitrogen produced by the synchronous decarbonization and nitrification reaction tank to quickly react and produce nitrogen under stirring, that is, to complete the second step of anaerobic ammonia oxidation. This process does not require high concentrations of dissolved oxygen, that is, no large amount of aeration is required, and only air flow stirring or mechanical stirring is required. On the one hand, it can prevent excessive oxygen from penetrating the protective film on the surface of the denitrification granular sludge and entering the interior due to large amounts of aeration, resulting in sludge deflocculation, breakage and loss; on the other hand, it can also avoid the problem of low ammonia nitrogen removal rate caused by insufficient aeration and an imbalance in the ratio of nitrite nitrogen and ammonia nitrogen, which can better ensure the quality of the denitrification granular sludge and promote the proliferation of the denitrification sludge.

[0165] ③ Biofilm anaerobic ammonia oxidation reaction tank is installed with biological ropes and polyurethane fillers. The denitrification sludge forms a biofilm on the biological ropes, and the polyurethane fillers intercept the denitrification sludge in the effluent, so that the denitrification sludge can be retained in the reaction tank as much as possible, avoiding the loss of denitrification sludge while maintaining a high sludge concentration, which is beneficial to improving the system's ability to resist impact. In order to prevent the sludge concentration from being too high and the sludge activity from being reduced, the biofilm can be regularly purged with air, and the detached denitrification sludge can be discharged from the system.

Claims

1. A method for treating ammonia nitrogen-containing wastewater, characterized in that: The following steps are involved: Passing ammonia nitrogen wastewater into a first reaction tank containing activated sludge, and passing air into the ammonia nitrogen wastewater to form dissolved oxygen, so as to carry out a decarbonization reaction and a nitrite reaction, and obtain a first treated liquid, wherein the ammonia nitrogen wastewater has an ammonia nitrogen content of ≤120 mg / L; the carbon source in the ammonia nitrogen wastewater is utilized by microorganisms and degraded into carbon dioxide, so as to carry out decarbonization; Passing the first treatment liquid into a sedimentation tank for sedimentation treatment to obtain a sedimentation treatment liquid; Passing the precipitation treatment liquid into a second reaction tank containing granular sludge, passing oxygen into the precipitation treatment liquid while stirring, so as to carry out anaerobic ammonia oxidation reaction of the granular sludge, and obtaining a second treatment liquid containing granular sludge after separation treatment; The second treated liquid is passed into a third reaction tank, and the granular sludge in the second treated liquid is filtered and retained by a filler assembly arranged in the third reaction tank to form a biofilm on the filler assembly, wherein the biofilm carries anaerobic ammonia-oxidizing bacteria to carry out a biofilm anaerobic ammonia-oxidizing reaction to obtain a third treated liquid.

2. The method for treating ammonia-nitrogen-containing wastewater according to claim 1, characterized in that: The content of dissolved oxygen in the first reaction tank is 0.5-2.5 mg / L, preferably 1.0-2.0 mg / L, and more preferably 1.2-1.8 mg / L.

3. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The sludge age in the first reaction tank is 1.7-6.0 d, preferably 2.0-5.0 d, and more preferably 2.5-4.5 d.

4. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The effluent B / C of the first treatment liquid is ≤0.3, preferably B / C ≤0.15, wherein B / C represents the mass ratio of biodegradable organic matter (BOD) to total organic matter (COD) in the wastewater.

5. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The effluent nitrite nitrogen NO2-N of the first treatment liquid is ≤60 mg / L, and the nitrate nitrogen NO3-N is ≤10 mg / L.

6. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The content of dissolved oxygen in the second reaction tank is 0.15-1.2 mg / L, preferably 0.2-1 mg / L, and more preferably 0.5-0.8 mg / L.

7. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The sludge load of the granular sludge in the second reaction tank is 0.06-0.9 kg TN / (kg VSS.d), preferably 0.1-0.8 kg TN / (kg VSS.d), and more preferably 0.2-0.6 kg TN / (kg VSS.d).

8. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The temperature in the second reaction tank is 30-39°C, preferably 33-38°C.

9. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The sludge concentration in the second reaction tank is 0.5-15 g / L, preferably 2-10 g / L; preferably, the sludge age is ≥11 days.

10. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The hydraulic retention time in the third reaction tank is 2-7h, preferably 3-6h, more preferably 4-5h; the temperature is 30-39°C, preferably 33-38°C.

11. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The total NH4+-N removal rate of the second reaction tank and the third reaction tank is ≥90%, and the total TN removal rate is ≥83%.

12. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The sludge concentration in the first reaction tank is 0.5-2 g / L, preferably 0.8-1.5 g / L.

13. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The temperature of the first reaction tank is 26-39°C, preferably 30-38°C, and the pH is 7.0-8.5, preferably 7.4-8.

0.

14. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The surface load of the sedimentation tank is ≤ 0.5m 3 / (m 2 .h), preferably ≤0.4m 3 / (m 2 .h); The suspended solids in the sedimentation tank effluent SS ≤ 200 mg / L, preferably SS ≤ 100 mg / L.

15. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The pH of the second treatment liquid is 6.7-8.3, preferably 7.4-8.0; preferably, the concentration of dissolved oxygen formed by introducing oxygen into the precipitation treatment liquid is 0.2-1.0 mg / L, preferably 0.4-0.8 mg / L.

16. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: The NH4+-N removal rate in the second reaction tank is ≥75%, and the TN removal rate is ≥65%.

17. The method for treating ammonia nitrogen-containing wastewater according to claim 1, characterized in that: In the biofilm anaerobic ammonia oxidation reaction, the pH of the liquid in the third reaction tank is 6.7-8.3, preferably 7.4-8.0; Preferably, the dissolved oxygen concentration of the reaction liquid is 0.2-1.5 mg / L, preferably 0.5-1.0 mg / L; Further preferably, the NH4+-N removal rate of the third reaction tank is ≥60%, and the TN removal rate is ≥50%.

18. A device for treating ammonia nitrogen-containing wastewater, used in the treatment method according to any one of claims 1 to 16, characterized in that: It includes a first reaction tank, a sedimentation tank, a second reaction tank with granular sludge and a third reaction tank which are sequentially connected by pipelines, and are used to form the first treatment liquid, the sedimentation treatment liquid, the second treatment liquid and the third treatment liquid respectively, and the pipeline is connected with a driving pump for pumping the ammonia nitrogen wastewater; The bottom of the first reaction tank, the second reaction tank and the third reaction tank are all provided with an aeration assembly for providing air to the liquid introduced into the first reaction tank, the second reaction tank and the third reaction tank; A blocking mechanism is provided between the liquid inlet and the liquid outlet of the sedimentation tank, which is used to intercept the mud in the first treatment liquid to form the sedimentation treatment liquid and guide it to the liquid outlet of the sedimentation tank; A packing frame is installed on the side wall of the third reaction tank away from the bottom of the tank. The packing assembly is fixed on the packing frame. The packing assembly includes polyurethane and a biological rope hung on the packing frame. The polyurethane is located on the side of the biological rope away from the bottom of the third reaction tank.

19. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: The aeration assembly comprises a first aeration duct mounted on the bottom of the first reaction tank and a first aerator disposed on the first perforated aeration duct, and one end of the first aeration duct away from the first aerator is connected to a first blower; The aeration assembly further comprises a second aeration duct mounted on the bottom of the second reaction tank and a second aerator disposed on the second aeration duct, wherein one end of the second aeration duct away from the second aerator is connected to a second blower; The aeration assembly further comprises a third aeration duct mounted on the bottom of the third reaction tank and a third aerator disposed on the third aeration duct. One end of the third aeration duct away from the third aerator is connected to a third blower.

20. The ammonia nitrogen-containing wastewater treatment device according to claim 19, characterized in that: The first aerator, the second aerator and the third aerator are microporous aeration disks or jet aerators.

21. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: The first reaction tank, the second reaction tank and the third reaction tank are respectively provided with a first water distribution pipe, a second water distribution pipe and a third water distribution pipe, the driving pump includes a first feed pump, a second feed pump and a third feed pump, the first feed pump is connected to the first reaction tank, and is used to pump ammonia nitrogen wastewater into the first reaction tank, the second feed pump is connected between the water outlet of the sedimentation tank and the water inlet end of the second water distribution pipe, and the third feed pump is connected between the water outlet of the second reaction tank and the water inlet end of the third water distribution pipe.

22. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: The blocking mechanism includes a plurality of baffles or a plurality of pipes fixed to the side wall of the sedimentation tank, and the baffles or the pipes are arranged at intervals and inclined relative to the bottom wall of the sedimentation tank.

23. The ammonia nitrogen-containing wastewater treatment device according to claim 22, characterized in that: The baffle or the pipe comprises a first section and a second section connected to each other. In the vertical direction, the first section is parallel to the side wall of the sedimentation tank, and the second section is obliquely intersected with the first section and the included angle between the second section and the first section is an obtuse angle.

24. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: A filtering mechanism is provided on the side wall of the second reaction tank near the top side. In the vertical direction, the filtering mechanism is located between the water inlet and the water outlet of the second reaction tank. The filtering mechanism includes a plurality of "herringbone" filter plates arranged in the horizontal direction and an "inverted herringbone" guide bucket located below the filter plate. The filter plate and the guide bucket are both fixed to the side wall of the second reaction tank. The openings of the filter plate and the guide bucket are opposite to each other. The filter plate has a first opening at one end away from the bottom of the tank, and the guide bucket has a second opening at one end close to the bottom of the tank. The filter plate is configured to guide the liquid in the second reaction tank to the water outlet through the first opening under the drive of the third feed pump, intercept and block the granular sludge in the liquid, and discharge it from the second opening along the inner wall of the guide bucket.

25. The ammonia nitrogen-containing wastewater treatment device according to claim 24, characterized in that: The filtering mechanism also includes an overflow groove and a water outlet weir that are connected. The overflow groove is arranged above the filter plate and is connected to the first opening. The water outlet weir is arranged on the side wall of the water outlet and is connected to the water outlet. The overflow groove is used to drain the liquid filtered by the filter plate to the water outlet weir.

26. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: A pressure releaser is provided below the bio-rope, the pressure releaser is fixed to the side wall of the third reaction tank and is connected to the second blower, and the pressure releaser is configured to release airflow toward the biofilm formed on the surface of the bio-rope.

27. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: The polyurethane includes hydrophilic polyurethane and / or hydrophobic polyurethane.

28. The ammonia nitrogen-containing wastewater treatment device according to claim 18, characterized in that: A sludge hopper is provided at the bottom of the sedimentation tank for collecting, storing and / or discharging sludge in the sedimentation tank; a sludge discharge port is provided on the side wall of the sedimentation tank close to the bottom of the tank, a sludge discharge pipe is passed through the sludge discharge port, one end of the sludge discharge pipe is connected to a sludge discharge pump, and the sludge discharge pump is connected to the first reaction tank. The sludge discharge pump is configured to discharge the sludge in the sedimentation tank through the sludge discharge pipe, or to discharge it to the first reaction tank, so as to regulate the sludge concentration and sludge age in the first reaction tank.

29. The ammonia nitrogen-containing wastewater treatment device according to claim 28, characterized in that: The sludge hopper has a conical flow-guiding surface, and one end of the sludge discharge pipe opposite to the end connected to the sludge discharge pump extends into the sedimentation tank and is close to the flow-guiding surface.

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