CN107188307A - A kind of Integral waste water nitrogen rejection facility and a kind of method of denitrogenation of waste water - Google Patents

Abstract

The invention provides an integrated wastewater denitrification device and a wastewater denitrification method. The device provided by the invention has simple structure and good stability and recovery. The present invention uses nitrifying bacteria and low-activity flocculent anammox sludge as the main body of the reactor, and selectively inhibits the growth and activity of nitrifying bacteria by intermittently adding a certain concentration of hydroxylamine and/or hydrazine over a long period of time. At the same time, the activity of ammonia oxidizing bacteria and anammox bacteria is promoted; the reactor adopts the operation mode of sequencing batch reactor, and the dilution of influent water containing high concentration of ammonia nitrogen is realized by adjusting the drainage ratio, so that the matrix concentration in the reactor Within a suitable range, it does not cause inhibition of short-range nitrification and anaerobic ammonium oxidation, improves the phenomenon of nitrate accumulation, and quickly restores the denitrification effect of the reactor.

Description

An integrated wastewater denitrification device and a wastewater denitrification method

technical field

The invention relates to the technical field of wastewater treatment, in particular to an integrated wastewater denitrification device and a wastewater denitrification method.

Background technique

Nitrogen pollution will cause eutrophication of water bodies, and with the rapid development of urbanization and industrialization in my country, this problem has become increasingly serious and has caused many public environmental safety incidents. For this reason, in recent years, the state has successively promulgated and implemented new sewage discharge standards, among which the discharge requirements for ammonia nitrogen have been particularly improved, and the total nitrogen in the effluent has been limited for the first time. At the same time, ammonia nitrogen has become a new total control indicator in the national "Twelfth Five-Year Plan". However, there are still a large number of problems in my country such as anaerobic digestion supernatant, photoelectric wastewater and other industrial wastewater that are difficult to treat. Due to the characteristics of high ammonia nitrogen and low carbon nitrogen ratio in this type of wastewater, it is particularly difficult to remove total nitrogen.

The traditional denitrification technology mostly adopts nitrification-denitrification technology. Because this technology requires a large amount of oxygen for nitrification and a large amount of organic carbon source for denitrification, it is especially suitable for treating wastewater with high ammonia nitrogen and low carbon to nitrogen ratio. Uneconomical and difficult. At present, international research hotspots have begun to turn to the denitrification process based on anaerobic ammonium oxidation. Anammox bacteria is a Gram-negative spherical bacterium, which uses ammonia nitrogen as an electron donor and nitrite as an electron acceptor to directly generate nitrogen through the oxidation-reduction reaction between nitrogen elements to achieve energy and carbon sources. saving. However, anammox bacteria grow very slowly and need to be grown in a reactor with a strong bioretention capacity. In engineering applications, the main form of nitrogen in actual wastewater is ammonia nitrogen. Therefore, the anammox process needs to be coupled with the nitrosation process. The coupling between the anammox process and the nitrosation process is mainly divided into two ways: 1. One is to use two reactors to connect, the two mainly carry out nitrosation and anammox respectively, and the other is to carry out nitrosation and anammox in the same reactor, which is called integrated denitrification. Compared with the split design, the integrated denitrification is easier to carry out project operation management due to its small number of structures. At the same time, because there is no separate nitrosation reactor, there is no problem of nitrite accumulation in the denitrification process, which improves operational safety. and reduce greenhouse gas N ₂ O emissions. However, when running the integrated reactor, it is necessary to selectively cultivate the ammonia oxidizing bacteria and anammox bacteria in the reactor, and at the same time inhibit the nitrifying bacteria; on the other hand, in practical applications, unstable water inflow often causes Fluctuation of the reactor, thereby inhibiting the reactor, therefore, the resilience of the reactor is also important.

To sum up, the existing anammox-based denitrification reactors have their own advantages, but also have their own shortcomings; in order to realize the long-term stable operation of the anammox process under high load and high influent concentration Strong recovery ability needs further improvement.

Contents of the invention

The object of the present invention is to provide an integrated wastewater denitrification device and a method for wastewater denitrification. The integrated wastewater denitrification device provided by the present invention has the characteristics of high load, high influent concentration, long-term stability and good recovery ability.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides an integrated wastewater denitrification device, comprising a reactor, a water inlet device, a water inlet pump, a water outlet pump, a return pump, a water bath device, an aeration pump, a stirring device and a water bath jacket;

Wherein, the water inlet device communicates with the water inlet at the lower part of the reactor through the water inlet pump;

The stirring device is arranged inside the reactor;

The water outlet pump communicates with the middle water outlet of the reactor;

The water-bath jacket wraps the side of the reactor, the outlet of the water-bath jacket communicates with the water-bath device, and the inlet of the water-bath jacket communicates with the water-bath device through a reflux pump;

The aeration pump is connected to the inner bottom of the reactor.

Preferably, the water inlet pump, water outlet pump, aeration pump and stirring device are independently connected to the controller.

Preferably, the upper part of the reactor is provided with an overflow port.

The present invention also provides a method for denitrifying wastewater using the integrated wastewater denitrification device described in any one of the above technical solutions, comprising the following steps:

(1) Add nitrification sludge, anammox sludge and filler in the reactor;

(2) Start the aeration pump and the stirring device, and feed water into the reactor by the water inlet pump;

(3) After the water intake is over, keep the aeration pump and stirring device running continuously for reaction;

(4) After the reaction is completed, the aeration pump and the stirring device stop running, so that the sludge is precipitated, and the supernatant is discharged by the outlet pump;

(5) Repeat steps (2) to (4), and continue to run several cycles to carry out the denitrification treatment of the wastewater;

During the wastewater denitrification treatment process, intermittently add hydroxylamine and/or hydrazine to the reactor.

Preferably, the frequency of adding hydroxylamine and/or hydrazine to the reactor is 3 to 5 days/time;

The amount of hydroxylamine and/or hydrazine added each time is 1-5 mg N/L.

Preferably, the inoculum amounts of the nitrification sludge and the anammox sludge are independently ≥ 6000 mg VSS/L.

Preferably, the volume filling ratio of the filler is 40-60%.

Preferably, during the wastewater denitrification treatment process, the water bath device and the reflux pump continue to operate to ensure the operating temperature of the reactor.

Preferably, the dissolved oxygen concentration inside the reactor is 0.1-1 mg/L during the wastewater denitrification treatment process, and the operating temperature of the reactor is 30-35°C.

The invention provides an integrated waste water denitrification device, comprising a reactor, a water inlet device, a water inlet pump, an outlet pump, a reflux pump, a water bath device, an aeration pump, a stirring device and a water bath jacket; wherein, the water inlet The device communicates with the water inlet of the lower part of the reactor through the water inlet pump; the stirring device is arranged inside the reactor; the water outlet pump communicates with the water outlet in the middle of the reactor; the water bath jacket wraps the side of the reactor, and the water bath The outlet of the jacket is communicated with the water bath device, and the inlet of the water bath jacket is communicated with the water bath device through a reflux pump; the aeration pump is connected to the inner bottom of the reactor. The device provided by the invention has simple structure and good stability and recovery. It overcomes the problems existing in the current integrated denitrification reactor that under long-term operation, nitrifying bacteria gradually gain an advantage in the competition with anammox bacteria, resulting in nitrate accumulation, poor impact resistance, poor stability, and weak recovery ability , which has a high denitrification load, strong long-term operation stability, and strong recovery ability after being strongly suppressed, so that it can achieve economical and efficient removal of total nitrogen.

The invention also provides a method for denitrification of waste water. The present invention uses nitrifying bacteria and low-activity flocculent anammox sludge as the main body of the reactor, and selectively inhibits the growth and activity of nitrifying bacteria by intermittently adding hydroxylamine and/or hydrazine for a long time, while promoting The activity of ammonia oxidizing bacteria and anammox bacteria; the reactor adopts the operation mode of sequencing batch reactor, and realizes the dilution of influent water containing high concentration of ammonia nitrogen by adjusting the drainage ratio, so that the concentration of ammonia nitrogen in the reactor is at a suitable level. Within the range, it will not cause the inhibition of short-range nitrification and anammox, improve the phenomenon of nitrate accumulation, and quickly restore the denitrification effect of the reactor.

Description of drawings

Fig. 1 is a structural schematic diagram of an integrated wastewater denitrification device;

Among them, 1-water inlet device, 2-water inlet pump, 3-reactor, 4-water outlet pump, 5-reflux pump, 6-water bath device, 7-aeration pump, 8-mixer, 9-stirring paddle, 10- Packing, 11 - water bath jacket.

detailed description

The invention provides an integrated wastewater denitrification device, comprising a reactor, a water inlet device, a water inlet pump, a water outlet pump, a return pump, a water bath device, an aeration pump, a stirring device and a water bath jacket;

Wherein, the water inlet device communicates with the water inlet at the lower part of the reactor through the water inlet pump;

The stirring device is arranged inside the reactor;

The water outlet pump communicates with the middle water outlet of the reactor;

The water-bath jacket wraps the side of the reactor, the outlet of the water-bath jacket communicates with the water-bath device, and the inlet of the water-bath jacket communicates with the water-bath device through a reflux pump;

The aeration pump is connected to the inner bottom of the reactor.

As a specific embodiment of the present invention, a schematic structural diagram of an integrated wastewater denitrification device provided by the present invention is shown in FIG. 1 . As can be seen from Figure 1, the integrated waste water denitrification device includes a reactor, water inlet device, water inlet pump, water outlet pump, reflux pump, water bath device, aeration pump, stirring device and water bath jacket; wherein, the water inlet The device communicates with the lower water inlet of the reactor through the water inlet pump; the stirring device includes a stirrer and a stirring paddle, and the stirring paddle is arranged inside the reactor; the water outlet pump communicates with the middle water outlet of the reactor; the water bath The jacket wraps the side of the reactor, the outlet of the water-bath jacket communicates with the water-bath device, the inlet of the water-bath jacket communicates with the water-bath device through a reflux pump; the aeration pump is connected to the inner bottom of the reactor.

The present invention does not have any special requirements on the specific models and structures of the reactor, water inlet device, water inlet pump, water outlet pump, reflux pump, water bath device, aeration pump, stirring device and water bath jacket, and uses wastewater treatment The components of the waste water treatment device well known to those skilled in the field of the device are sufficient.

The present invention does not have any special requirements on the aspect ratio of the reactor. In a specific embodiment of the present invention, the aspect ratio of the reactor is preferably 4-8, more preferably 5-6.

As a preferred embodiment of the present invention, the water inlet pump, the water outlet pump, the aeration pump and the stirring device are independently connected to the controller, and the controller automatically performs the operation of the water inlet pump, the water outlet pump, the aeration pump and the stirring device. regulation.

As a preferred embodiment of the present invention, the upper part of the reactor is provided with an overflow port.

The present invention also provides a method for denitrifying wastewater using the integrated wastewater denitrification device described in any one of the above technical solutions, comprising the following steps:

(1) Add nitrification sludge, anammox sludge and filler in the reactor;

(2) Start the aeration pump and the stirring device, and feed water into the reactor by the water inlet pump;

(3) After the water intake is over, keep the aeration pump and stirring device running continuously for reaction;

(4) After the reaction is completed, the aeration pump and the stirring device stop running, so that the sludge is precipitated, and the supernatant is discharged by the outlet pump;

(5) Repeat steps (2) to (4), and continue to run several cycles to carry out the denitrification treatment of the wastewater;

During the wastewater denitrification treatment process, intermittently add hydroxylamine and/or hydrazine to the reactor.

In the invention, nitrifying sludge, anaerobic ammonium oxidation sludge and filler are firstly added into the reactor. The present invention has no special requirements on the order of adding the nitrification sludge, anammox sludge and filler, and the three can be added in any order.

In the present invention, the dominant species in the nitrification sludge is Nitrosomonas, and the dominant species in the anammox sludge is Candidatus Kuenenia. The present invention does not have any special requirements on the sources of the nitrification sludge and the anammox sludge, and the nitrification sludge and the anammox sludge for wastewater treatment well known to those skilled in the art can be used.

In the present invention, the inoculation amount of the nitrification sludge and the anammox sludge is independently preferably ≥6000mgVSS/L, more preferably ≥7000mgVSS/L, most preferably ≥8000mgVSS/L. In a specific embodiment of the present invention, the inoculation amount of the nitrification sludge and the anammox sludge is independently preferably 6000-10000 mg VSS/L, more preferably 7000-9000 mg VSS/L, most preferably 8000 mg VSS/L L.

In the present invention, the filler is preferably a plastic filler. The present invention does not have any special requirements on the type and source of the plastic filler, and the rate filler commonly used by those skilled in the art can be used. In a specific embodiment of the present invention, the filler is preferably columnar, with a height of 1 cm and a diameter of 1 cm. In the present invention, the volume filling ratio of the filler is preferably 40-60%, more preferably 45-55%. The filler selected in the present invention has a good film-hanging effect.

In the present invention, after the nitrification sludge, anammox sludge and filler are added, the initial pH value in the reactor is preferably 7-8, more preferably 7.5.

After adding nitrification sludge, anaerobic ammonia oxidation sludge and filler into the reactor, the invention starts the aeration pump and the stirring device, and feeds water into the reactor through the water inlet pump. In the present invention, after starting the aeration pump and the stirring device for a certain period of time, the water inlet pump is turned on to feed water into the reactor to enhance mass transfer, and at the same time, the matrix in the feed water is quickly consumed, so that the ammonia nitrogen in the reactor is not correct for ammonia nitrogen. Oxidizing bacteria and anammox bacteria are inhibited; the certain time is preferably 10-20s, more preferably 15-16s.

In the present invention, the aeration rate is preferably based on controlling the concentration of dissolved oxygen in the wastewater denitrification treatment process to be 0.1-1 mg/L, more preferably 0.2-0.8 mg/L, most preferably 0.4-0.6 mg/L.

In the present invention, the stirring rate of the stirring device is preferably 100-140 rpm, more preferably 110-130 rpm, most preferably 120 rpm.

In the present invention, the duration of water inflow in each cycle is 1-3 minutes, and the amount of water inflow in 1-3 minutes is preferably 0.5-1 L, more preferably 0.6-0.8 L. In the present invention, the influent can specifically be any kind of ammonia nitrogen wastewater.

In the present invention, at the initial stage of start-up, the concentration of NH ₄ Cl in the influent water quality is preferably ≤200mgN/L, and as the operating condition of the reactor is optimized, the concentration of NH ₄ Cl in the influent water quality is preferably ≥250mgN/L /L, when the reactor achieves stable operation, the concentration of NH ₄ Cl in the influent water quality is preferably ≥300mgN/L, but generally not more than 500mgN/L. In a specific embodiment of the present invention, the concentration of NH ₄ Cl in the influent water quality is preferably 200-330 mgN/L, more preferably 250-300 mgN/L; the concentration of KH ₂ PO ₄ is preferably 10-45 mgP/L, More preferably 20-30 mgP/L; the concentration of CaCl ₂ is preferably 150-320 mg/L, more preferably 200-280 mg/L; the concentration of MgSO ₄ 7H ₂ O is preferably 100-220 mg/L, more preferably 180 ～200mg/L; the concentration of _NaHCO3 is preferably 15～20mg/L, more preferably 16～18g/L; the concentration of trace element solution I is preferably 0.5mg/L; the concentration of trace element solution II is preferably 1.5～2.5 mg/L, more preferably 2mg/L.

In a specific embodiment of the present invention, the composition of the trace element solution I is (g/L): FeSO ₄ 7.5-8.5, EDTA 5; the composition of the trace element solution II is (g/L): EDTA 15, CuSO ₄ 5H ₂ O 0.22～0.24, ZnSO ₄ 7H ₂ O 0.43, NiCl ₂ 6H ₂ O 0.18～0.19, NaSeO ₄ 10H ₂ O 0.21, NaMoO ₄ 2H ₂ O 0.22, H ₃ BO ₄ 0.014, MnCl ₂ · 4H ₂ O 0.99, zinc chloride 0.26g/L.

After the water inflow is finished, the present invention keeps the aeration pump and the stirring device running continuously to carry out the reaction. In the present invention, the reaction is specifically a biological process in which bacteria in nitrification sludge and anammox sludge absorb solutes such as ammonia nitrogen in wastewater. In the present invention, the reaction time of the reaction phase in each cycle is preferably 30 to 120 min, and is preferably 90 to 120 min in the reactor start-up phase. As the reactor operating condition is optimized, the reaction time is preferably 50 to 80 min. When the reactor When stable operation is achieved, the reaction time is preferably 30-40 minutes.

After the reaction is completed, the present invention keeps the aeration pump and the stirring device out of operation, so that the sludge is precipitated, and the supernatant is discharged by the outlet pump. In the present invention, the discharge ratio of the effluent is preferably 10-30%, more preferably 15-25%, most preferably 20%. The present invention regulates the concentration of the ammonia nitrogen substrate in the reactor by controlling the drainage ratio. The drainage ratio of the present invention can control the ammonia nitrogen concentration in the reactor to be 100-120 mg/L, preferably 105-115 mg/L.

After the drainage is completed, the present invention repeats steps (2) to (4), and continues to operate for several cycles to carry out the denitrification treatment of the wastewater. In the present invention, each cycle includes a water inlet stage, a reaction stage, a precipitation stage and a water outlet stage.

During the above wastewater denitrification treatment process, the present invention intermittently adds hydroxylamine and/or hydrazine to the reactor. In the present invention, the frequency of adding hydroxylamine and/or hydrazine to the reactor is preferably once every 3-5 days, more preferably once every four days.

In the present invention, once every 3 to 5 days specifically refers to adding hydroxylamine and/or hydrazine to the water in the water inflow stage of each cycle within one day after every 3 to 5 days; specifically For example, when the frequency is once every 4 days, hydroxylamine and/or hydrazine are added to the influent in the influent stage of all cycles on the fifth day after every four days.

In the present invention, the amount of hydroxylamine and/or hydrazine added each time is preferably 1 to 5 mg N/L (in terms of influent volume, that is, the concentration of hydroxylamine and/or hydrazine in influent), more preferably It is preferably 2-4 mg N/L, most preferably 3 mg N/L.

In the present invention, intermittently adding hydroxylamine and/or hydrazine to the integrated denitrification reactor from the start of the reactor can promote nitrification and anaerobic ammonium oxidation, and at the same time selectively inhibit nitrification, thereby facilitating the reaction Fast start-up and long-term stable operation of the controller.

During the wastewater denitrification treatment process, the water bath device and the reflux pump continue to operate to ensure the operating temperature of the reactor. In the present invention, the operating temperature of the water bath device is preferably 30-35°C, more preferably 31-34°C, most preferably 32-33°C.

An integrated wastewater denitrification device and a wastewater denitrification method provided by the present invention will be described in detail below in conjunction with the examples, but they should not be construed as limiting the protection scope of the present invention.

Example 1

Influent water composition: NH ₄ Cl (concentration 200mgN/L), KH ₂ PO ₄ (concentration 45mg P/L), CaCl ₂ (concentration 150mg/L), MgSO ₄ 7H ₂ O (concentration 100mg/L), NaHCO ₃ (concentration 15g/L), trace element solution I 1mL/L, trace element solution II 0.5mL/L. Trace elements I include ferrous sulfate 8.5g/L and EDTA sodium salt 5g/L. Trace elements II include EDTA sodium salt 15g/L, manganese chloride 0.99g/L, copper sulfate 0.24g/L, zinc chloride 0.26g/L, NaSeO ₄ 10H ₂ O 0.21, NaMoO ₄ 2H ₂ O 0.22, H ₃ BO ₄ 0.014 and nickel chloride 0.18g/L.

The aeration pump and stirring equipment are turned on before the water enters, and the water enters the reactor 3 from below for reaction. During the reaction process, the aeration pump 7 continuously aerates to provide dissolved oxygen (0.1-1 mg/L) in the reactor, and the agitator 8 (120 rpm) continuously agitates to enhance mass transfer.

After the reaction is completed, the aeration pump 7 and the mixer 8 are stopped to allow the sludge to settle, and the supernatant is discharged to the drain bucket through the drain pipe to start the next cycle.

A water-bath jacket is set in the reactor 3, and the water in the water-bath jacket is discharged into the water-bath pot 6, and then pumped back to the water-bath jacket again via the reflux pump 5 to form a water-bath cycle, providing temperature conditions (32° C. for the reaction environment in the reactor 3) ).

During the operation, add hydroxylamine at the same time and dissolve it in the influent water. The frequency of addition is once every 3 to 5 days, and the concentration of addition is 2mg N/L. By adding hydroxylamine, Reactor 3 can start up and reach a total nitrogen removal load of 1.02kgN/(m ³ ·d) after 13 days after inoculation of nitrification sludge and flocculent anammox sludge; Adding hydroxylamine to the one-piece reactor that caused instability due to the inhibition of dissolved oxygen quickly improved the excessive accumulation of nitrate in the effluent, and after 40 days of operation, the total nitrogen removal load of the reactor was reduced from 0.88kgN/(m ³ · d) Increased to 1.69kgN/(m ³ ·d), the total nitrogen removal rate increased from 69.5% to 85.5%. The inhibitory effect of hydroxylamine on NOB was reversible (nitrate in the effluent began to accumulate excessively 7 days after the addition of hydroxylamine was stopped).

In the present invention, the reactor of cycle operation is roughly divided into three stages:

The first stage is when the reactor is just started, the drainage ratio is 0.1, the effluent ammonia nitrogen concentration is 1.2-5.0mg/L, the nitrite nitrogen concentration is 2-3.0mg/L, the nitrate concentration is 1.0-4.2mg/L, and the total nitrogen removal rate 72-84%;

The second stage is when the reactor operation gradually matures, the drainage ratio reaches 0.2, the effluent ammonia nitrogen concentration is 1.2-7.5mg/L, the nitrite nitrogen concentration is 1.2-8.0mg/L, the nitrate concentration is 5.0-20.0mg/L, the total nitrogen The removal rate is 83-86%. At the same time, the nitrite nitrogen concentration in the effluent is low, and the nitrate accumulation ratio is controlled around 0.12-0.15, indicating that the NOB activity is low;

The third stage is when the reactor operation reaches the optimal state, the drainage ratio reaches 0.3, the effluent ammonia nitrogen concentration is 0-4.0mg/L, the nitrite nitrogen concentration is 0.5-3.6mg/L, and the nitrate concentration is 10.0-13.0mg/L. The total nitrogen removal rate was 87-89%. At the same time, the nitrite nitrogen concentration in the effluent was low, and the nitrate accumulation ratio was controlled at 0.11, indicating that the NOB activity was low.

It can be known from the above embodiments that the present invention provides an integrated wastewater denitrification device and a wastewater denitrification method. The device provided by the invention has simple structure and good stability and recovery. The present invention uses nitrifying bacteria and low-activity flocculent anammox sludge as the main body of the reactor, and selectively inhibits the growth and activity of nitrifying bacteria by intermittently adding a certain concentration of hydroxylamine and/or hydrazine over a long period of time. At the same time, the activity of ammonia oxidizing bacteria and anammox bacteria is promoted; the reactor adopts the operation mode of sequencing batch reactor, and the dilution of influent water containing high concentration of ammonia nitrogen is realized by adjusting the drainage ratio, so that the matrix concentration in the reactor Within a suitable range, it does not cause inhibition of short-range nitrification and anaerobic ammonium oxidation, improves the phenomenon of nitrate accumulation, and quickly restores the denitrification effect of the reactor.

The above is only a preferred embodiment of the present invention, and it should be pointed out that for those of ordinary skill in the art, some improvements and modifications can be made without departing from the principle of the present invention. It should be regarded as the protection scope of the present invention.

Claims (9)

1. An integrated wastewater denitrification device, comprising a reactor, a water inlet device, a water inlet pump, an outlet pump, a return pump, a water bath device, an aeration pump, a stirring device and a water bath jacket; Wherein, the water inlet device communicates with the water inlet at the lower part of the reactor through the water inlet pump; The stirring device is arranged inside the reactor; The water outlet pump communicates with the middle water outlet of the reactor; The water-bath jacket wraps the side of the reactor, the outlet of the water-bath jacket communicates with the water-bath device, and the inlet of the water-bath jacket communicates with the water-bath device through a reflux pump; The aeration pump is connected to the inner bottom of the reactor. 2. The integrated waste water denitrification device according to claim 1, characterized in that the water inlet pump, water outlet pump, aeration pump and stirring device are independently connected to the controller. 3. The integrated waste water denitrification device according to claim 1, characterized in that an overflow port is arranged on the upper part of the reactor. 4. A method for denitrification of wastewater using the integrated wastewater denitrification device described in any one of claims 1 to 3, comprising the following steps: (1) Add nitrification sludge, anammox sludge and filler in the reactor; (2) Start the aeration pump and the stirring device, and feed water into the reactor by the water inlet pump; (3) After the water intake is over, keep the aeration pump and stirring device running continuously for reaction; (4) After the reaction is completed, the aeration pump and the stirring device stop running, so that the sludge is precipitated, and the supernatant is discharged by the outlet pump; (5) Repeat steps (2) to (4), and continue to run several cycles to carry out the denitrification treatment of the wastewater; During the wastewater denitrification treatment process, intermittently add hydroxylamine and/or hydrazine to the reactor. 5. The method for denitrifying wastewater according to claim 4, wherein the frequency of adding hydroxylamine and/or hydrazine to the reactor is 3 to 5 days/time; The amount of hydroxylamine and/or hydrazine added each time is 1-5 mgN/L. 6. The method for denitrification of wastewater according to claim 4, characterized in that the inoculum amounts of the nitrification sludge and the anammox sludge are independently ≥ 6000 mgVSS/L. 7. The method for denitrification of wastewater according to claim 4, characterized in that the volume filling ratio of the filler is 40-60%. 8. The method for denitrification of wastewater according to claim 4, characterized in that, during the wastewater denitrification process, the water bath device and the reflux pump continue to operate to ensure the operating temperature of the reactor. 9. The method for denitrification of wastewater according to claim 4, characterized in that the concentration of dissolved oxygen inside the reactor during the wastewater denitrification treatment process is 0.1 to 1 mg/L, and the operating temperature of the reactor is 30 to 1 mg/L. 35°C.