CN117003382A

CN117003382A - PN/A reaction system and reaction process for coupling front-end short-range denitrification

Info

Publication number: CN117003382A
Application number: CN202311078370.2A
Authority: CN
Inventors: 刘旭; 王思琦; 史绪川; 何钜源; 陈福明; 刘淑杰; 王艳青
Original assignee: Guangdong Qingyan Environmental Technology Co ltd
Current assignee: Guangdong Qingyan Environmental Technology Co ltd
Priority date: 2023-08-25
Filing date: 2023-08-25
Publication date: 2023-11-07
Anticipated expiration: 2043-08-25
Also published as: CN117003382B

Abstract

The invention provides a PN/A reaction system and a reaction process for coupling front-end short-range denitrification. The reaction system comprises a short-cut denitrification reaction tank and a PN/A reaction tank, wherein the short-cut denitrification reaction tank is provided with a total water inlet pipe, the short-cut denitrification reaction tank is communicated with the PN/A reaction tank through a connecting pipe, the PN/A reaction tank comprises an integrated tank body, a control module, a drainage module, a quality-separating mud discharging module and a degassing module, the drainage module is arranged in the reaction tank and comprises a water outlet unit and a backflow water unit, the backflow water unit is communicated with the water outlet unit and the total water inlet pipe, a circulation sedimentation zone is formed in the integrated tank body, and a primary sedimentation zone and a secondary sedimentation zone are formed in the circulation sedimentation zone by adjusting the rising flow rate of mixed liquor in the circulation sedimentation zone, wherein the primary sedimentation zone is positioned above the secondary sedimentation zone.

Description

PN/A reaction system and reaction process for coupling front-end short-range denitrification

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a PN/A reaction system and a reaction process for coupling front-end short-range denitrification.

Background

The treatment of high ammonia nitrogen wastewater has been one of the key research directions in the field of industrial wastewater treatment, and an anaerobic ammonia oxidation (Anaerobic ammonium oxidation, anammox) process is used to perform denitrification treatment on the high ammonia nitrogen wastewater, and under the anoxic condition, ammonia is used as an electron donor, and nitrous nitrogen is used as an electron acceptor to oxidize ammonia into nitrogen. The short-cut nitrification-anaerobic ammonia oxidation (partial nitritation and anammox, PN/A) process derived on the basis can realize autotrophic denitrification under the condition of no carbon source, saves aeration energy consumption by 60%, and is a promising high-efficiency biological denitrification process.

However, the soluble contaminants in industrial wastewater typically include organics that enter directly into the short-cut nitrification-anaerobic ammoxidation reaction tank, which may cause the proliferation of heterotrophic bacteria to affect the stability of the short-cut nitrification-anaerobic ammoxidation reaction. The advanced short-cut denitrification can utilize carbon sources and nitrate nitrogen in industrial wastewater and provide a required nitrous matrix for the subsequent anaerobic ammoxidation reaction. Thus, it may be considered to combine short-cut denitrification with PN/a process, for example, chinese patent application publication No. CN113845222a discloses a device and method for implementing advanced denitrification of domestic sewage by two-stage process of drainage endogenous short-cut denitrification/anaerobic ammoxidation, which implements short-cut denitrification-anaerobic ammoxidation reaction by adding an intermediate water tank, accumulating carbon source.

The current process of combining short-cut denitrification, short-cut nitrification and anaerobic ammoxidation reaction generally exists in three ways: 1. the three reactions are respectively completed in three devices, and the device provided by the method is complex, the control mode is complex and the economic benefit is extremely low; 2. the short-range denitrification and the anaerobic ammoxidation are directly combined in a reaction system, firstly, nitrate nitrogen in water is reduced into nitrite nitrogen by denitrifying bacteria, then, the nitrite nitrogen and residual ammonia nitrogen in water are converted into nitrogen by anaerobic ammoxidation bacteria (AnAOB) to be discharged out of the system, and the proliferation speeds of the denitrifying bacteria and the AnAOB are greatly different, so that the system is unstable, the sludge is discharged out unsmooth, and the system is crashed; 3. short-cut nitrification-anaerobic ammoxidation reaction is carried out in a system, short-cut nitrifying bacteria (AOB) generate short-cut nitrifying action, ammonia nitrogen is converted into nitrosamine, anAOB converts ammonia nitrogen and nitrosamine into nitrogen, the nitrogen removal action is achieved, the AOB grows faster than AnAOB and generates more short-cut nitrifying action, ammonia nitrogen is converted into nitrosamine, and the nitrosamine is not consumed by AnAOB; on the other hand, the generated nitrogen drives the sludge to float upwards and simultaneously drives AnAOB to drain and run away along with the effluent; the nitrosamine is continuously accumulated, and then the AnAOB is inhibited, and finally the whole system is crashed.

Therefore, it is desirable to provide a PN/a reaction system and reaction process that can operate stably for a long period of time and that enables self-adjusting coupled front-end short-cut denitrification.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a PN/A reaction system and a reaction process for coupling front-end short-range denitrification; the aeration can be automatically regulated according to the water quality condition, the short-cut denitrification, short-cut nitrification and anaerobic ammoxidation can be simultaneously carried out by regulating the sludge proportion in the reaction tank through the quality-separating sludge discharge, the solid-liquid-gas three-phase automatic separation can be realized, and the long-term stable operation can be realized.

The PN/A reaction system comprises a short-cut denitrification reaction tank and a PN/A reaction tank, wherein the short-cut denitrification reaction tank is provided with a total water inlet pipe, the short-cut denitrification reaction tank is communicated with the PN/A reaction tank through a connecting pipe, the PN/A reaction tank comprises an integrated tank body, a control module, a drainage module, a quality-divided mud discharging module and a degassing module, the drainage module is arranged in the reaction tank, the drainage module comprises a water outlet unit and a backflow water unit, the backflow water unit is communicated with the water outlet unit and the total water inlet pipe, a circulating sedimentation zone is formed in the integrated tank body, a primary sedimentation zone and a secondary sedimentation zone are formed in the circulating sedimentation zone by adjusting the rising flow rate of mixed liquid in the circulating sedimentation zone, and the primary sedimentation zone is positioned above the secondary sedimentation zone.

Further, the water outlet unit comprises a water discharge weir and a water discharge pipe, the water discharge weir is arranged at the center of the top of the integrated tank body, one end of the water discharge pipe is arranged at the bottom of the water discharge weir, the other end of the water discharge pipe penetrates through the side wall of the integrated tank body to be communicated with the outside, one end of the water return unit is arranged on the pipe wall of the water discharge pipe, and the other end of the water return unit is connected to the total water inlet pipe.

Further, the quality-dividing sludge discharge module comprises a sludge discharge pipe, a collecting part, an up-flow regulating pipe and a reflux pump, wherein one end of the sludge discharge pipe is communicated with the primary sedimentation zone, and the other end of the sludge discharge pipe is communicated with the collecting part; one end of the up-flow regulating pipe is communicated with the secondary sedimentation zone, and the other end of the up-flow regulating pipe is communicated with the clear liquid part of the collecting part; the reflux pump is used for refluxing the clear liquid in the collecting part into the secondary sedimentation zone.

Further, a degassing module is further arranged in the integrated tank body, the degassing module is arranged on two sides of the drainage module, and the circulating sedimentation area is located below the degassing module.

Further, the control module includes: the device comprises an aeration unit positioned at the bottom of the integrated tank body, a monitoring unit positioned in the integrated tank body, a pH value adjusting device and a temperature adjusting device.

Further, the aeration unit comprises an aeration pipeline and a fan; the monitoring unit comprises a sludge concentration monitor, a dissolved oxygen concentration monitor, a pH value monitor, a temperature monitor, a nitrite nitrogen concentration monitor and an ammonia nitrogen concentration monitor.

Further, the short-cut denitrification reaction tank is an MBR tank provided with a membrane filtration system, or the short-cut denitrification reaction tank 100 is provided with a biological membrane filler.

According to a second aspect of the present invention there is provided a coupled pre-short cut denitrification PN/A reaction process, characterised in that the reaction process comprises the steps of:

step I, inoculating denitrifying bacteria in a short-cut denitrification reaction tank, and inoculating short-cut nitrifying bacteria and anaerobic ammonia oxidizing bacteria in a PN/A reaction tank;

step II, pumping sewage into the short-cut denitrification reaction tank, and performing short-cut denitrification reaction, wherein the reacted liquid is discharged into the PN/A reaction tank, and the PN/A reaction tank comprises an integrated tank body;

step III, enabling the liquid discharged into the PN/A reaction tank in the step II to enter an integrated tank body, and enabling the liquid to contact with sludge in the integrated tank body to perform a short-cut nitrification-anaerobic ammonia oxidation reaction in a sludge water mixture mode;

And IV, performing mud-water separation on the mud-water mixture after the reaction in the integrated tank body, and then discharging supernatant fluid after the mud-water separation.

Further, in the step IV, the supernatant fluid after mud-water separation is discharged as:

step IV-1, monitoring the concentration of ammonia nitrogen in the inlet water, and when the concentration of the ammonia nitrogen in the inlet water exceeds a preset value, refluxing the supernatant into the short-range denitrification reaction tank according to a calculated reflux ratio, carrying out short-range denitrification reaction together with sewage newly pumped into the short-range denitrification reaction tank, and then repeating the step II, the step III and the step IV; or alternatively

And step IV-1', monitoring the ammonia nitrogen concentration of the supernatant fluid in the integrated tank body after mud-water separation, and discharging the supernatant fluid to the outside when the ammonia nitrogen concentration is lower than a preset value.

Further, the step III includes:

the short-cut nitrification reaction and the anaerobic ammonia oxidation reaction are simultaneously performed by controlling the aeration amount while controlling the concentration of ammonia nitrogen to be in a range of more than 20mg/L, the concentration of nitrous nitrogen to be in a range of less than 50mg/L, and the concentration of dissolved oxygen to be in a range of not more than 0.5 mg/L.

Further, the reaction process further comprises: and V, stopping water entering the short-range denitrification reaction tank when the sludge concentration in the PN/A reaction tank exceeds a preset value range, and starting to perform quality-dividing and sludge discharging on the PN/A reaction tank.

Further, the step V includes:

v-1, forming a circulating sedimentation zone in the integrated tank body, and dividing the circulating sedimentation zone into a primary sedimentation zone and a secondary sedimentation zone by adjusting the rising flow rate, wherein the secondary sedimentation zone is positioned below the primary sedimentation zone;

v-2, discharging sludge in the primary sedimentation zone through a sludge discharge pipe;

v-3, carrying out secondary sedimentation on the sludge discharged in the step V-2 in a collecting part, and refluxing the clarified liquid in the collecting part into the secondary sedimentation zone through the up-flow regulating pipe;

and V-4, adjusting the rising flow rate in the reaction tank by adjusting the reflux rate of the clarified liquid.

The PN/A reaction system for coupling the front-end short-cut denitrification combines the short-cut denitrification reaction tank with the short-cut nitrification-anaerobic ammonia oxidation reaction tank (PN/A reaction tank), discharges clear liquid after short-cut denitrification treatment into the PN/A reaction tank, and then returns supernatant liquid which is reacted by the PN/A reaction tank and subjected to mud-water separation into the short-cut denitrification reaction tank, so that a small amount of nitrate and organic pollutants (COD) in the supernatant liquid can be fully removed. The short-cut denitrification reaction tank in the reaction system can be an MBR tank provided with a membrane filtration system, or the short-cut denitrification reaction tank is provided with a fixed or suspended biological membrane filler, sludge can be trapped in the tank or attached to grow on a biological membrane, and then clear liquid is discharged into the PN/A reaction tank, so that denitrifying bacteria are prevented from being brought into the PN/A reaction tank, and the subsequent short-cut nitrification-anaerobic ammonia oxidation reaction cannot be influenced.

In addition, the PN/A reaction tank is provided with a monitoring module and an adjusting module to realize that short-cut nitrification and anaerobic ammoxidation reactions are carried out in one reaction tank at the same time, the reactions in the PN/A reaction tank and the short-cut denitrification reaction tank can also be carried out at the same time, and the PN/A reaction tank can realize the processes of short-cut nitrification-anaerobic ammoxidation reaction and mud-water separation. And when the monitoring unit monitors that the sludge concentration in the PN/A reaction tank exceeds a preset value, the proportion of different sludge in the reactor can be controlled and regulated, so that the reduction of the denitrification performance of the system caused by the growth of inhibiting AnAOB by excessive nitrosamine generated by the growth of AOB is avoided, and the stable operation of the biochemical reaction in the integrated tank body is ensured.

Furthermore, the PN/A reaction process for coupling the front-end short-cut denitrification can realize automatic control and adjustment of aeration quantity, further control the concentration of dissolved oxygen, ammonia nitrogen and nitrite nitrogen in water, enable the short-cut denitrification reaction, the short-cut denitrification reaction and the anaerobic ammoxidation reaction to be simultaneously and automatically carried out, prevent denitrifying bacteria from being carried into the next reaction stage through biological membrane interception in a short-cut denitrification reaction tank, enable mud-water separation of mud-water mixture after the short-cut nitrification-anaerobic ammoxidation reaction, enable clear liquid to flow back to carry out short-cut denitrification with newly pumped sewage, and therefore can improve the total nitrogen removal rate of the process, and the total nitrogen removal rate can reach more than 95%, for example, can reach 98%.

Drawings

FIG. 1 is an overall schematic diagram of a PN/A reaction system coupled to a pre-short cut denitrification in accordance with the present application.

FIG. 2 is a schematic perspective view of a PN/A reaction tank in a PN/A reaction system coupled with a pre-short cut denitrification according to the present application.

FIG. 3 is a schematic side view of PN/A reaction cells in a PN/A reaction system coupled with a pre-short cut denitrification according to the present application.

FIG. 4 is a schematic front view of PN/A reaction cells in a PN/A reaction system coupled with a pre-short cut denitrification according to the present application.

Detailed Description

The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments. The principles and features of the present application are described below with reference to the drawings, and it should be noted that embodiments of the present application and features of the embodiments may be combined with each other without conflict. The illustrated embodiments are merely illustrative of the application and are not intended to limit the scope of the application.

The first aspect of the present application provides a PN/a reaction system 10 coupled with a pre-short-cut denitrification, the reaction system 10 comprising a short-cut denitrification reaction tank 100 and a PN/a reaction tank 200, the short-cut denitrification reaction tank 100 being provided with a total water inlet pipe 120, the short-cut denitrification reaction tank 100 being in communication with the PN/a reaction tank 200 via a connection pipe 130, the short-cut denitrification reaction tank 100 being pumped into the short-cut denitrification reaction tank 100 via a water inlet pipe by an external water pump after the reaction system 10 is started, the water inlet pipe being opened, for example, on a bottom plate or a side wall of the short-cut denitrification reaction tank 100, preferably being opened at a lower portion of the side wall 100 of the short-cut denitrification reaction tank, forming water inlet from below the short-cut denitrification reaction tank 100.

Further, the PN/a reaction tank 200 includes an integrated tank body 210 and a control module, and a drainage module 220, a quality-divided sludge discharge module 230 and a degassing module 240 which are provided in the reaction tank, the drainage module 220 includes a water outlet unit 221 and a water return unit 222, the water return unit 222 communicates with the water outlet unit 221 and the total water inlet pipe 120, a circulation sedimentation zone 260 is formed in the integrated tank body 210, and a primary sedimentation zone 261 and a secondary sedimentation zone 262 are formed in the circulation sedimentation zone 260 by adjusting an ascending flow rate of a mixed liquid in the circulation sedimentation zone 260, wherein the primary sedimentation zone 261 is located above the secondary sedimentation zone 262.

After the sewage is subjected to short-cut denitrification treatment, sludge is trapped in the short-cut denitrification reaction tank 100, and liquid after short-cut denitrification reaction is clear liquid and flows into the PN/A reaction tank 200 through the connecting pipe 130. The supernatant is subjected to a short-cut nitrification-anaerobic ammoxidation reaction in the PN/A reaction tank 200, the reacted sludge-water mixture can be subjected to sludge-water separation in the PN/A reaction tank 200, and the supernatant is discharged through the water discharge module 220, at this time, the ammonia nitrogen concentration of the inlet water and the outlet water is monitored, the reflux ratio is calculated, and the supernatant in the PN/A reaction tank is refluxed into the short-cut denitrification reaction tank through the reflux water unit 222 or discharged to the outside through the water outlet unit 221 according to the reflux ratio, and the specific judgment mode will be described later. The above-mentioned discharged material can be directly discharged, also can be discharged into water reservoir for storage, and can be used for subsequent reuse. The return water unit 222 may be a water pipe.

It will be appreciated that the reaction system provided by the present application is typically provided with some solid waste filtration means upstream of it to enable the removal of impurities from the water. In addition, the contaminants in the water referred to in the present application are mainly nitrogen-containing contaminants and COD, and the nitrogen-containing contaminants generally include ammonia nitrogen, nitrate nitrogen and nitrite nitrogen, and throughout the context, nitrate nitrogen and nitrate in the present application may be understood as the same nitrogen-containing contaminants, and nitrite nitrogen, nitrite nitrogen and nitrite may be understood as the same nitrogen-containing contaminants, for convenience of description.

Based on this, denitrifying bacteria are inoculated in the short-cut denitrification reaction tank 100, and the denitrifying bacteria can consume a biodegradable part COD existing in the inflow water, reduce nitrate nitrogen in supernatant fluid reflux in the PN/A reaction tank 200 into nitrite nitrogen, and provide the nitrite nitrogen for subsequent anaerobic ammoxidation reaction. On one hand, the COD in the raw water is fully utilized, the overall denitrification efficiency is improved, and on the other hand, the adverse effect on anaerobic ammonia oxidizing bacteria caused by that part of COD enters into the PN/A pool is avoided.

In addition, in the PN/A reaction tank 200, the excessive growth speed of the AOB can cause the increase of the AOB, the generated nitrous nitrogen increase can inhibit the growth of the AnAOB and influence the anaerobic ammoxidation reaction, and the application discharges flocculent AOB outside the PN/A reaction tank 200 through the differential sludge discharge module 230 and retains the AnAOB in the reaction tank, thereby regulating and controlling the proportion of the AOB to the AnAOB so as to ensure the stable operation of a system. The action principle is as follows: the settling rate of AOB sludge in water is slow and thus floc sludge is formed into primary settling zone 261, while the AnAOB sludge is fast and thus granular sludge is formed into secondary settling zone 262. The split mud discharging module 230 maintains the rising flow rate between the settling rates of AOB and AnAOB by adjusting the rising flow rate in the loop settling zone 260, which enables rapid splitting of AOB and AnAOB, and discharges AOB into the primary settling zone 261 after splitting while retaining AnAOB in the secondary settling zone 262, thereby adjusting the proportion of sludge in the loop settling zone 260 in the integrated tank 210.

Further, since the final product of denitrification is nitrogen, an air floatation phenomenon may occur in the process of floating nitrogen from the liquid, the phenomenon may cause the nitrogen to drive part AnAOB to rise, and the AnAOB is lost along with water discharge, and since the degassing module 240 is arranged in the reaction tank, the loss of the AnAOB can be avoided, and the stable operation of the system is further ensured.

According to the reaction system 10 provided by the application, the preposed short-range denitrification reaction tank 100 is coupled on the basis of the PN/A reaction tank 200, and ammonia nitrogen in water can be further treated by utilizing COD in sewage through the short-range denitrification reaction, so that the denitrification rate of the reaction system 10 can be improved, three reactions can be simultaneously carried out, the stability of water inlet and outlet is ensured, the stage reaction is not needed, the treatment time is saved, and the treatment efficiency is improved. In addition, the reaction system 10 provided by the application is provided with the quality-separating and sludge-discharging module 230 and the degassing module 240, and the sludge proportion in the self-adjusting integrated tank body 210 and the three-phase separation are realized through the control module, so that the economic benefit is greatly improved.

The structure of each module of the present application will be described in detail with reference to the accompanying drawings.

Specifically, in some embodiments, the water outlet unit 221 includes a water discharge weir 2211 and a water discharge pipe 2212, the water discharge weir 2211 is disposed at the top center of the integrated tank 210, and preferably the water discharge weir 2211 is disposed along the length direction of the integrated tank 210. One end of the drain pipe 2212 is formed at the bottom of the drain weir 2211, and the other end passes through the side wall of the integrated tank 210 to be connected with the outside, preferably, the drain pipe 2212 is formed at a position of the drain weir 2211 close to the side wall of the tank, and the height of the one end is lower than that of the other end relative to the other end, so that water accumulation in the drain weir 2211 after the drainage is stopped is avoided. In some embodiments, as shown in fig. 3, one end of the backflow water unit 222 is opened on the wall of the drain pipe 2212, and the other end is connected to the general water inlet pipe 120. The two ends of the backflow water unit 222 may be opened on the drain pipe 2212 and the main water inlet pipe 120, for example, in the form of a branch pipe, or may be directly opened on the drain pipe 2212 and the main water inlet pipe 120, and at this time, the backflow water unit 222 may be a water pipe with connection joints at two ends, so as to be connected to the branch pipe, and be capable of backflow of the supernatant flowing out of the drain pipe 2212 into the short-range denitrification reaction tank 100.

Further, in an embodiment, the mass-separation mud discharging module 230 includes a mud discharging pipe 231, a collecting portion 232, an up-flow adjusting pipe 233 and a reflux pump 234, wherein one end of the mud discharging pipe 231 is communicated with the primary sedimentation region 261, the other end is communicated with the collecting portion 232, one end of the up-flow adjusting pipe 233 is communicated with the secondary sedimentation region 262, and the other end is communicated with the clear liquid portion of the collecting portion 232; the reflux pump 234 is used to reflux the supernatant in the collection section 232 into the secondary settling zone, and in some preferred embodiments, the reflux pump 234 may be disposed in the up-flow regulator tube 233 or in the collection section to reflux the supernatant.

Specifically, one end of the sludge discharge pipe 231 communicates with the primary sedimentation zone 261 and the other end communicates with the collecting portion 232, so that at the start of sludge discharge, the sludge discharge pipe 231 can discharge only sludge in the primary sedimentation zone 261 while retaining sludge in the secondary sedimentation zone 262. The sludge discharged through the sludge discharge pipe 231 enters the collecting part 232, secondary sedimentation is carried out in the collecting part 232, sludge and water separation occurs in the sludge after secondary sedimentation in the collecting part 232, separated clear liquid flows back to the secondary sedimentation zone 262 in the integrated tank body 210 through the upward flow adjusting pipe 233, on the one hand, the sludge discharge operation of the sludge discharge pipe 231 can be realized, on the other hand, the adjustment of the upward flow rate in the circulating sedimentation zone 260 can be realized due to the arrangement of the reflux pump 234, for example, the flow rate of the clear liquid flowing back to the secondary sedimentation zone 262 through the upward flow adjusting pipe 233 can be adjusted by adjusting the reflux rate of the reflux pump, and on the other hand, the upward flow rate can be provided for the circulating sedimentation zone of the integrated tank body due to the fact that one end, which is communicated with the secondary sedimentation zone 262, of the upward flow adjusting pipe 233 is positioned below, and at this moment, the upward flow rate is adjusted to be greater than the sedimentation rate of the AOB and is smaller than the sedimentation rate of the AOB, thus the granular AnAOB can be settled to the secondary sedimentation zone 262, and the AOB enters the primary sedimentation zone 261. Thus, the quality-divided discharge of the sludge in the integrated tank body 210 can be realized, the proportion of the sludge is regulated and controlled, the quality-divided sludge discharge is realized, the sewage treatment cost is reduced, and the stable operation of the system is ensured.

It should be appreciated that during the initial period of starting the split sludge discharge module 230, since the rising flow rate is not specifically controlled, mixed sludge may be discharged, and since the rising flow rate is very rapidly adjusted, the sludge in the integrated tank 210 is rapidly split, and at this time, after the rising flow rate is stabilized, the AOB in the primary settling zone 261 is stably output, and the AnAOB at the bottom is not discharged. In another embodiment, in the initial sludge discharge stage, the rising flow rate can be adjusted by adjusting the aeration quantity, so that the sludge is classified, and aeration is stopped after the sludge is classified, and the classification sludge discharge module is utilized for further adjusting the rising flow rate.

In some preferred embodiments of the present invention, the collecting part 232 may be a secondary sedimentation tank, a sludge-water separation tank or other devices for sludge-water separation, which may include only one tank body for sludge-water separation, or may separate the separated sludge from the clear liquid by separating the tank body with a partition, and at this time, it is only necessary to ensure that the end of the up-flow adjusting pipe 233 connected thereto is inserted into the clear liquid, so that the sludge is prevented from flowing back into the integrated tank body 210.

In addition, in other embodiments of the present invention, a second sludge discharge pipe, in which the sludge discharge pump is disposed for discharging the AnAOB in the secondary sedimentation zone 262 to the second collecting portion, and a second collecting portion, in which there is no need to provide a device for refluxing the clear liquid on the second collecting portion, may be provided.

The sludge discharge cycle may be started, for example, when the whole short-cut denitrification-short-cut nitrification-anaerobic ammonia oxidation reaction is performed for 10 days, 15 days or 30 days, or according to the result monitored by the control module, when the sludge concentration in the integrated tank 210 of the PN/a reaction tank 200 is monitored to rise to a preset value, the preset value may be, for example, the concentration of AOB, or the concentration ratio of AOB to AnAOB, and when the preset value is the concentration ratio of AOB to AnAOB, the preset value may be, for example, 3:1, that is, the ratio is greater than 3:1, the sludge discharge module 230 is started to discharge sludge.

As described above, the nitrous nitrogen and the ammonia nitrogen in the water are converted into nitrogen after the anaerobic ammoxidation reaction, and the nitrogen in the water leaves the reaction system, and at this time, the nitrogen in the water may drive part of AnAOB to rise due to the air floatation effect in the process of floating up, so that AnAOB is lost along with the water discharge. For this purpose, the integrated tank 210 of the present invention is provided with a degassing module 240, so as to avoid loss of AnAOB driven by gas.

Specifically, in one embodiment, the degassing module 240 is disposed at both sides of the drainage module 220, in which case the primary settling zone 261 and the secondary settling zone 262 are located below the degassing module 240. In some preferred embodiments, the degassing module 240 includes a pair of degassing units 241 disposed opposite to each other, and a downward flow channel, i.e., a sinking zone, is formed between the degassing units 241 and the inner wall of the integrated tank 210, and sewage flows into the integrated tank 210 from above the side wall of the integrated tank 210. An upward flow passage through which gas is discharged is formed between the opposite degassing units 241. In this case, the above-mentioned loop sedimentation zone 260 is formed below the degassing unit 241, whereby sludge is classified below the degassing unit 241, the ascending flow rate provided by the ascending flow regulating pipe 233 and the return pump 234 in the classified sludge discharging module 230 may directly form an upward flow path between the degassing units 241, and gas may be directly discharged through the upward flow path along the ascending flow rate. Thus, three-phase separation is realized, the economic benefit is improved, and multiple purposes are achieved. In another embodiment of the present invention, the degassing module 240 may be, for example, a three-phase separator, and may directly separate three components of gas, liquid and solid in the mud-water separation device.

The processes of short-cut denitrification, short-cut nitrification, anaerobic ammonia oxidation, quality-separating sludge discharge and the like can be regulated and controlled by a control module. In some embodiments of the invention, the control module comprises: the aeration unit 250 at the bottom of the integrated tank 210, the monitoring unit at the inside of the integrated tank 210, the ph adjusting device and the temperature adjusting device, and further comprises flow control adjustment (adjusting the rising flow rate) during sludge discharge, and reflux amount adjustment from the PN/a reaction tank to the short-range denitrification tank. In some preferred embodiments, the reaction system 10 of the present invention further includes a master controller and a control circuit, where the master controller is typically located at a location convenient for personnel to operate, such as near a reaction cell or at a master console, where the master controller is coupled to the control module, the drainage module 220, and the mass and mud removal module 230 via the control circuit to control the start and stop of each module and to adjust the reaction system 10 in time. Therefore, the invention realizes intelligent automatic control on sewage denitrification treatment.

Further, in some embodiments, the aeration unit 250 of the present invention includes an aeration pipe and a blower, the aeration pipe is communicated under the integrated tank 210, the blower may be disposed outside the integrated tank 210, or directly connected to an external air supply system, thereby controlling the aeration amount by controlling the flow rate of air blown into the integrated tank 210, and thus adjusting the dissolved oxygen content in the integrated tank 210.

Further, the monitoring unit comprises a sludge concentration monitor, a dissolved oxygen concentration monitor, a pH value monitor, a temperature monitor, a nitrous nitrogen concentration monitor and an ammonia nitrogen concentration monitor, wherein the sludge concentration monitor can monitor the contents of AOB and AnAOB in the reaction tank and the proportion of the two types of sludge; other monitors can monitor the concentration of dissolved oxygen, pH, temperature, concentration of nitrous nitrogen, concentration of ammonia nitrogen, etc. in the integrated tank 210, respectively; the adjusting module comprises a PH value adjusting device and a temperature adjusting device. In some preferred embodiments, two ammonia nitrogen concentration monitors of the present application may be provided, and the two ammonia nitrogen concentration monitors are respectively provided in the short-cut denitrification reaction tank and the integrated tank body, more preferably, the two ammonia nitrogen concentration monitors are located at the water inlet of the short-cut denitrification reaction tank and in the supernatant liquid area of the integrated tank body, and are respectively used for measuring the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant liquid.

In addition, in some embodiments, the monitoring unit of the present application may be further provided with a sewage volume detecting device or an infrared water level monitor, etc., which may be installed as needed by those skilled in the art, and the present application is not limited thereto. The ph adjusting device may be, for example, a container provided with a pumping device, and the container may be filled with a buffer solution, so that the ph is adjusted by pumping the buffer solution, and the temperature adjusting device may be, for example, a cooling or heating device such as a fan or a resistance wire, and the present application is not particularly limited thereto.

It should be understood that the above-mentioned water outlet unit 221 and water return unit 222 may be provided therein with solenoid valves, and the opening and closing of the solenoid valves in the water outlet unit 221 and water return unit 222 may be controlled according to the ammonia nitrogen concentrations of the water inlet and supernatant monitored in real time, so as to adjust the flow direction of the supernatant.

Further, in order to avoid bringing denitrifying bacteria into the PN/A reaction tank 200, the short-cut denitrification reaction tank 100 may be configured as an MBR tank, or biofilm packing may be disposed therein, which may be fixed or suspended. When sewage enters the short-cut denitrification reaction tank 100, mixed denitrifying bacteria in the sewage can be trapped by a membrane in the MBR tank or by biofilm packing 110 in the short-cut denitrification reaction tank 100. The liquid flowing out of the short-cut denitrification reaction tank 100 is clean water, and no denitrifying bacteria carried along with the liquid are contained.

Thus, the PN/A reaction system 10 coupled with the front-end short-cut denitrification combines the short-cut denitrification reaction tank 100 with the PN/A reaction tank 200, and the biological membrane filler 110 or the MBR tank is arranged in the short-cut denitrification reaction tank 100, so that denitrifying bacteria are trapped on the biological membrane and prevented from entering the PN/A reaction tank 200, and the effluent of the short-cut denitrification reaction tank 100 is a clear solution, that is, the sludge of the denitrifying bacteria in the short-cut denitrification reaction tank 100 is not contained.

In addition, the clear liquid after the short-cut nitrification-anaerobic ammoxidation reaction in the PN/A reaction tank 200 is returned to the short-cut denitrification reaction tank 100 together with the newly pumped sewage through the water inlet pipe, and nitrate nitrogen in the clear liquid is reduced into nitrite nitrogen, so that more nitrite nitrogen sources are provided for the PN/A reaction tank 200. The reactions in the two reaction tanks can be carried out simultaneously without stage treatment.

The PN/A reaction tank 200 provided by the invention can regulate the content of dissolved oxygen in the integrated tank body 210 due to the arrangement of the aeration unit 250, and further control the ammonia nitrogen concentration and the nitrite nitrogen concentration in the integrated tank body 210. Through setting up the matter separation mud discharging module 230, can selectively discharge the AOB in the integration cell body 210, and remain AnAOB to regulate and control the proportion of AOB and AnAOB in the integration cell body 210, thereby make the system can steady operation. Due to the arrangement of the degassing module 240, the invention can realize three-phase separation without loss of AnAOB in the tank body, thereby ensuring economic benefit. By arranging the water draining module 220, the invention can drain the treated clean water to the outside for subsequent use.

Based on the structure, the reaction system provided by the invention can stably run to realize automatic sludge discharge, and due to the arrangement of an MBR reaction tank or biological filler, the influence of denitrifying bacteria on the reaction of AOB and AnAOB in a PN/A reaction tank can be avoided, in addition, the quality-separated sludge discharge can be started by detecting the concentration of sludge, so that the stable running of the system is ensured, the denitrification efficiency is greatly improved, COD in water is utilized as a carbon source in the short-range denitrification process while denitrification is realized, the additional carbon source is avoided, the cost is saved, and the device is simple and convenient to maintain and care. The PN/A reaction system 10 for coupling the front-end short-range denitrification integrates COD removal, ammonia nitrogen removal, mud-water separation and quality separation and sludge discharge in water, and has very high economic benefit.

Based on a second aspect of the present invention, there is provided a PN/a reaction process coupled to a pre-short cut denitrification, the reaction process comprising the steps of: step I, inoculating denitrifying bacteria in a short-cut denitrification reaction tank, and inoculating short-cut nitrifying bacteria and anaerobic ammonia oxidizing bacteria in a PN/A reaction tank.

And II, pumping sewage into the short-range denitrification reaction tank, performing short-range denitrification reaction, and discharging the reacted liquid into the PN/A reaction tank, wherein the PN/A reaction tank comprises an integrated tank body. In the process, a fixed or suspended biological membrane carrier filler is arranged in the short-cut denitrification reaction tank, or the short-cut denitrification reaction tank is set into an MBR tank, so that denitrifying bacteria in sewage are trapped in the short-cut denitrification reaction tank, and liquid discharged to the PN/A reaction tank in the process is clean water. In the reaction process, sewage and sludge do not exist in a short-cut denitrification reaction tank in a muddy water mixing state, but flow through a biological membrane to react with denitrifying bacteria on the biological membrane, then the denitrifying bacteria are continuously trapped on the biological membrane, and ammonia nitrogen in the sewage is reduced into nitrite nitrogen after the sewage passes through a biological membrane filler.

Subsequently, the liquid discharged into the PN/A reaction tank in the step III enters an integrated tank body, and contacts with sludge in the integrated tank body to perform short-cut nitrification-anaerobic ammonia oxidation reaction in the form of a sludge water mixture. Specifically, the step III includes controlling the aeration amount while controlling the concentration of ammonia nitrogen to be in a range of more than 20mg/L, controlling the concentration of nitrite nitrogen to be in a range of less than 50mg/L, and controlling the concentration of dissolved oxygen to be in a range of not more than 0.5mg/L, so that the short-cut nitrification reaction and the anaerobic ammonia oxidation reaction are simultaneously performed. In some preferred embodiments of the present invention, the ph during the reaction of step III is controlled in the range of 6.5 to 8.3. By controlling the ammonia nitrogen concentration, the nitrite nitrogen concentration and the dissolved oxygen concentration within the preset ranges, the short-cut nitrification reaction and the anaerobic ammonia oxidation reaction in the PN/A reaction tank can be performed simultaneously without stage performance, and the stability of water inlet and water outlet can be ensured without stopping water inlet and water outlet to start the short-cut nitrification-anaerobic ammonia oxidation reaction.

And next, performing mud-water separation on the reacted mud-water mixture in the integrated tank body, and then discharging supernatant fluid after mud-water separation.

In some embodiments of the invention, the supernatant fluid after mud-water separation is discharged in step IV as:

step IV-1, monitoring the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant, and according to the relation between the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant, adding the supernatant:

and (3) refluxing the wastewater into a short-cut denitrification reaction tank, carrying out short-cut denitrification reaction together with the wastewater newly pumped into the short-cut denitrification reaction tank, and repeating the step (II), the step (III) and the step (IV). Under the condition, a certain amount of nitrate is contained in the supernatant in the integrated tank body, the supernatant which flows back into the short-cut denitrification reaction tank and nitrate in sewage which is newly pumped into the short-cut denitrification reaction tank are reduced into nitrite nitrogen, and COD in water can be used as a carbon source required by the short-cut denitrification reaction in the process, so that the COD in water can be removed by the reaction process provided by the invention. The reduced nitrite nitrogen enters the integrated tank body along with water to jointly generate anaerobic ammonia oxidation reaction with nitrite nitrogen formed by short-range nitrification and a small amount of residual ammonia nitrogen (namely residual ammonia nitrogen after short-range digestion) in the integrated tank body, and finally nitrogen is formed and discharged out of the reaction system.

Or directly discharging the supernatant to the outside according to the relationship between the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant, for example, directly discharging the supernatant, or discharging the supernatant into a water reservoir for storage, and then recycling the supernatant.

Specifically, in some preferred embodiments of the present application, the relationship between the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant fluid may be a relationship in which the two are compared with a preset value, that is, in an example, in the case where the ammonia nitrogen concentration of the inlet water exceeds the preset value, the supernatant fluid is directly returned to the short-cut denitrification reaction tank; when the ammonia nitrogen concentration of the inlet water is below a preset value, the denitrification efficiency of more than 90% can be achieved, so that the supernatant fluid can be directly discharged to the outside. In another embodiment, the ammonia nitrogen concentration of the supernatant may be compared with another preset value, for example, the other preset value may be an ammonia nitrogen emission standard, that is, when the ammonia nitrogen concentration of the supernatant is higher than the ammonia nitrogen emission standard, the supernatant is returned to the short-path denitrification reaction tank, and when the ammonia nitrogen concentration of the supernatant is lower than the preset value, the supernatant is directly emitted to the outside.

Further, in the most preferred embodiment of the present application, the relationship between the ammonia nitrogen concentration of the above-described intake water and the ammonia nitrogen concentration of the supernatant fluid may be a reflux ratio calculated by the following formula:

the ammonia nitrogen concentration standard of the effluent and the total nitrogen concentration standard of the effluent are determined according to the policies executed in each place or the standard concentration in the national standard, so that the preset value of the reflux ratio is pre-calculated and set according to the ammonia nitrogen concentration standard of the effluent, the total nitrogen concentration standard of the effluent and the ammonia nitrogen and total nitrogen concentration of the influent in the policies executed in each place or the national standard. For example, if the ammonia nitrogen concentration of the sewage water in a certain area is 800mg/L, the ammonia nitrogen concentration standard of the effluent water is 10mg/L, and the total nitrogen concentration standard of the effluent water is 20mg/L, the calculated reflux ratio is 7.69, and at the moment, the reflux ratio can be set to be 7.69. It should be noted that the above examples are only for illustrating the way of calculating the reflux ratio of the reaction process of the present application, and are not limited thereto. When the reaction system and the reaction process are used in different areas or even countries, the sewage discharge standard and the ammonia nitrogen concentration of the inlet water are changed and have certain fluctuation in different periods, so that the reflux ratio is generally calculated according to local average values, and the reflux ratio is adjusted to adapt to sewage treatment in different areas, thereby meeting the sewage denitrification treatment requirements in different areas.

In fact, when the reaction process is stably operated, under the condition that the supernatant fluid is returned to the short-range denitrification reaction tank, the step II can reduce ammonia nitrogen in water to nitrite nitrogen while removing COD in water, and a small amount of COD in water is used as a carbon source without adding additional carbon source, so that more nitrite nitrogen is provided for the reaction in the step III, and the reaction efficiency is improved.

Based on the method, the PN/A reaction process for coupling the front-end short-cut denitrification integrates removal of COD in water and removal of ammonia nitrogen in water, and can be automatically carried out without manual adjustment and conversion. The theoretical denitrification rate is up to more than 95%, preferably up to 98%.

As described above, since the AOB has a higher growth rate than AnAOB during the short-cut nitrification-anaerobic ammoxidation reaction, and the short-cut denitrification reaction supplies nitrous nitrogen to the subsequent steps, the nitrous nitrogen concentration in the PN/a reaction cell increases with the increase of the treatment time, and when the nitrous nitrogen concentration is too high, the growth of AnAOB is suppressed, and the system collapses, in order to avoid this. In some embodiments, the PN/a reaction process of the coupled pre-short-cut denitrification of the present invention further includes step V of stopping water inflow to the short-cut denitrification reaction tank 100 and starting to perform quality-classified sludge discharge to the PN/a reaction tank when it is detected that the sludge concentration in the PN/a reaction tank 200 exceeds a preset value range.

Specifically, in some embodiments, the step V includes: v-1, forming a circulating sedimentation zone in an integrated tank body, and dividing the circulating sedimentation zone into a primary sedimentation zone and a secondary sedimentation zone by adjusting the rising flow velocity, wherein the secondary sedimentation zone is positioned below the primary sedimentation zone; v-2, discharging sludge in the primary sedimentation zone through a sludge discharge pipe; v-3, carrying out secondary sedimentation on the sludge discharged in the step V-2 in a collecting part, and refluxing the clarified liquid in the collecting part into the secondary sedimentation zone; and V-4, adjusting the rising flow rate in the integrated tank body by adjusting the reflux rate of the clarified liquid. Specifically, the sludge discharged from the sludge discharge pipe is secondarily settled in the collecting part to form settled sludge and clarified liquid, and the clarified liquid flows back into the secondary settling zone, so that the rising flow velocity is provided in the integrated tank body, the rising flow velocity in the integrated tank body can be regulated by regulating the return flow velocity at the moment, therefore, the quality of mixed sludge in the integrated tank body can be divided, flocculent AOB enters the primary settling zone, granular AnAOB enters the secondary settling zone, and accordingly, the quality-divided sludge discharge is realized, and the proportion of the AOB sludge and the AnAOB sludge in the system is stabilized within a certain range, so that the stable operation of the process is maintained.

In some embodiments, in the above step V, the preset value of the sludge concentration may be, for example, the concentration of AOB or the ratio of AOB to AnAOB concentration, which may be, for example, 3:1. And after the preset value of the sludge concentration is higher than the preset value, starting the quality-dividing and sludge-discharging process until the sludge concentration is lower than the proportion, stopping the quality-dividing and sludge-discharging process, and continuing to operate the steps II to IV.

Therefore, the reaction process provided by the invention can continuously and stably run, namely ammonia nitrogen and COD in water can be stably removed, a carbon source is not required to be provided in the short-cut denitrification process, and denitrifying bacteria cannot enter the next stage to influence AOB and AnAOB. Can realize automatic mud discharge, easy operation does not need personnel to monitor, convenient adjustment and maintenance.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate an azimuth or a positional relationship based on that shown in the drawings, and that the direction of the end plate for fixing the water outlet pipe is defined as a front direction unless otherwise specified, and that the front and rear directions may be interchanged with each other if specifically specified; this is merely to facilitate describing the invention and to simplify the description and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element discussed below could be termed a second element without departing from the teachings of the present invention. Similarly, a second element may also be referred to as a first element.

In the description of the present specification, the descriptions of the terms "one embodiment," "some embodiments," "examples," "particular examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples described in this specification and the features of the various embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Claims

1. The PN/A reaction system is characterized by comprising a short-cut denitrification reaction tank and a PN/A reaction tank, wherein the short-cut denitrification reaction tank is provided with a total water inlet pipe, the short-cut denitrification reaction tank is communicated with the PN/A reaction tank through a connecting pipe, the PN/A reaction tank comprises an integrated tank body, a control module, a drainage module, a quality-separating mud discharging module and a degassing module, the drainage module comprises a water outlet unit and a backflow water unit, the backflow water unit is communicated with the water outlet unit and the total water inlet pipe, a circular flow sedimentation zone is formed in the integrated tank body, and a primary sedimentation zone and a secondary sedimentation zone are formed in the circular flow sedimentation zone by adjusting the rising flow rate of mixed liquid in the circular flow sedimentation zone, wherein the primary sedimentation zone is positioned above the secondary sedimentation zone.

2. The PN/a reaction system for coupling front-end short-cut denitrification according to claim 1, wherein the water outlet unit comprises a water discharge weir and a water discharge pipe, the water discharge weir is arranged at the center of the top of the integrated tank body, one end of the water discharge pipe is arranged at the bottom of the water discharge weir, the other end of the water discharge pipe passes through the side wall of the integrated tank body and is communicated with the outside, and one end of the water return unit is arranged on the pipe wall of the water discharge pipe, and the other end of the water return unit is connected to the total water inlet pipe.

3. The coupled pre-short cut denitrification PN/A reaction system according to claim 2, wherein the split sludge discharge module comprises a sludge discharge pipe, a collecting part, an up-flow regulating pipe and a reflux pump, wherein one end of the sludge discharge pipe is communicated with the primary sedimentation zone, and the other end of the sludge discharge pipe is communicated with the collecting part; one end of the up-flow regulating pipe is communicated with the secondary sedimentation zone, and the other end of the up-flow regulating pipe is communicated with the clear liquid part of the collecting part; the reflux pump is used for refluxing the clear liquid in the collecting part into the secondary sedimentation zone.

4. The PN/a reaction system for coupling front-end short-cut denitrification according to claim 3, wherein a degassing module is further provided in the integrated tank body, the degassing module is disposed at two sides of the drainage module, and the circulating sedimentation zone is located below the degassing module.

5. The coupled pre-short cut denitrification PN/A reaction system of claim 4, wherein the control module comprises: the device comprises an aeration unit positioned at the bottom of the integrated tank body, a monitoring unit positioned in the integrated tank body, a pH value adjusting device and a temperature adjusting device.

6. The coupled pre-short cut denitrification PN/A reaction system according to claim 5, wherein the aeration unit comprises an aeration pipe and a fan; the monitoring unit comprises a sludge concentration monitor, a dissolved oxygen concentration monitor, a pH value monitor, a temperature monitor, a nitrite nitrogen concentration monitor and an ammonia nitrogen concentration monitor.

7. The PN/a reaction system for coupled pre-short cut denitrification according to any one of claims 1 to 6, wherein the short cut denitrification reaction tank is an MBR tank provided with a membrane filtration system or the short cut denitrification reaction tank is provided with a biofilm packing.

8. The PN/A reaction process for coupling the front-end short-range denitrification is characterized by comprising the following steps of:

9. The PN/a reaction process for coupling pre-short cut denitrification according to claim 8, wherein the discharging of the supernatant fluid after the sludge-water separation in the step IV is:

Step IV-1, monitoring the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant, and according to the relation between the ammonia nitrogen concentration of the inlet water and the ammonia nitrogen concentration of the supernatant, carrying out the steps:

reflux to the short-cut denitrification reaction tank, and carrying out short-cut denitrification reaction together with sewage newly pumped into the short-cut denitrification reaction tank; or alternatively

Is discharged to the outside.

10. The coupled pre-short cut denitrification PN/A reaction process according to claim 8, wherein the step III comprises:

11. The coupled pre-short cut denitrification PN/a reaction process according to any one of claims 8 to 10, further comprising: and V, stopping water entering the short-range denitrification reaction tank when the sludge concentration in the PN/A reaction tank exceeds a preset value range, and starting to perform quality-dividing and sludge discharging on the PN/A reaction tank.

12. The coupled pre-short cut denitrification PN/a reaction process of claim 11, wherein step V comprises:

and V-4, adjusting the rising flow rate in the integrated tank body by adjusting the reflux rate of the clarified liquid.