WO2011050639A1

WO2011050639A1 - Reaction apparatus for simultaneous denitrification and dephosphorization with two-sludge and biofilm processes

Info

Publication number: WO2011050639A1
Application number: PCT/CN2010/075756
Authority: WO
Inventors: 周少奇; 张晓洁
Original assignee: 华南理工大学
Priority date: 2009-10-30
Filing date: 2010-08-06
Publication date: 2011-05-05

Abstract

A reaction apparatus for simultaneously denitrifying and dephosphorizing with two-sludge and biofilm processes is provided, which comprises a 1^# sequencing batch reactor (2), a 2^# sequencing batch reactor (5) and a nitrate exchanger (9). The 1^# sequencing batch reactor (2) is connected to a first intake pump (1) by a pipeline, and also connected to the nitrate exchanger (9) by a pipeline. The nitrate exchanger (9) is connected to the 1^# sequencing batch reactor (2) via a third intake pump (7), and connected to the 2^# sequencing batch reactor (5) via a second intake pump (4). In addition, the 2^# sequencing batch reactor (5) is also connected to the nitrate exchanger (9) by a pipeline. An activated sludge process and biofilm process are combined and used in the apparatus, such that the contradiction between denitrification and dephosphorization in conventional process is solved.

Description

Double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment

Technical field

The invention relates to a denitrification simultaneous nitrogen and phosphorus removal device Specifically, the combination of activated sludge method and biofilm method is used to culture nitrifying bacteria and denitrifying phosphorus removal bacteria in different sludge systems to create the best for nitrifying bacteria and denitrifying phosphorus removal bacteria. Growing environment to improve the effect of nitrogen and phosphorus removal.

Background technique

Denitrifying dephosphatation technology refers to denitrifying phosphorus removal bacteria (Denitrifying Phosphorus removal Bacteria, referred to as DPB) After anaerobic phosphorus release, nitrate is used as an electron acceptor for phosphorus uptake under hypoxic conditions to simultaneously achieve nitrogen removal and phosphorus removal. Denitrifying phosphorus-removing bacteria have been shown to have metabolic characteristics that are very similar to aerobic phosphorus-removing bacteria. Because denitrifying phosphorus removal bacteria can take phosphorus in anoxic environment , This allows the two biological processes of phosphorus uptake and denitrification and denitrification to be carried out in the same environment by the same type of microorganisms: the simultaneous removal of nitrogen and phosphorus can be achieved by consuming only the amount of organic matter required for phosphorus removal by a separate organism; In the anoxic environment, phosphorus is replaced by nitrate as an electron acceptor for absorbing phosphate, which saves the amount of aeration; denitrification and phosphorus removal are completed by the same kind of bacteria, and sludge production can be reduced. This new type of sewage treatment technology is quite suitable for the current transition of sewage treatment to sustainable development: purification of water by nitrogen and phosphorus removal, low power consumption, and low sludge production. COD consumption is low. It is a new type of high efficiency and low energy consumption biological nitrogen and phosphorus removal technology.

Summary of the invention

The object of the present invention is to provide a denitrification and simultaneous nitrogen and phosphorus removal reaction device capable of simultaneously realizing nitrifying bacteria and denitrifying phosphorus removal bacteria in a set of equipment.

The invention adopts the combination of the activated sludge method and the biofilm method, and separately cultures the nitrifying bacteria and the denitrifying phosphorus removal bacteria in different sludge systems to create the best growth for the nitrifying bacteria and the denitrifying phosphorus removing bacteria. Environment, to achieve ideal nitrification and denitrifying phosphorus removal, to achieve the purpose of improving nitrogen and phosphorus removal.

In order to achieve the above object, the present invention adopts the following technical solutions:

Double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment, including 1 ^# sequencing batch reactor, 2 ^# sequencing batch reactor and nitrate exchanger; 1 ^# sequencing batch reactor through pipeline and first feed water pump The connection is also connected to the nitrate exchanger through a first drain valve; the nitrate exchanger is connected to the 1 ^# sequencing batch reactor via a third feed pump, and is also connected to the 2 ^# sequencing batch reactor via a second feed pump. The 2 ^# sequencing batch reactor is further connected to the nitrate exchanger through a second drain valve; the 1 ^# sequencing batch reactor and the 2 ^# sequencing batch reactor are respectively provided with a second blower and a first blower.

The 1 ^# sequencing batch reactor is also provided with a stirrer.

The 1 ^# sequencing batch reactor and the 2 ^# sequencing batch reactor are double-layered cylindrical structures, and a cavity for holding hot water is arranged in the middle, and the constant temperature water bath is respectively passed through the pipeline with the 1 ^# sequencing batch reactor. It is connected to the intermediate cavity of the double-layer cylinder of the 2 ^# sequencing batch reactor.

The device further includes a PLC programmable controller, and the programmable controller is respectively connected to the first water pump, the second water pump, and the third The inlet pump, the first blower, the first drain valve, the second drain valve, the agitator and the second blower are connected.

The 1 ^# sequencing batch reactor or the 2 ^# sequencing batch reactor is prepared by plexiglass.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention employs two sequencing batch reactors and a nitrate exchanger, of which 2 The reactors only exchange the supernatant during the reaction cycle, and do not exchange the respective activated sludge, forming a double mud system, which has a simple structure and convenient operation and maintenance.

(2) 2 ^# sequencing batch reactor is an independent aerobic nitrification tank, which is nitrated by membrane method and added with fiber membrane as filler to facilitate the growth and reproduction of nitrifying bacteria, so that it can be grown without nitrification. Created stable conditions.

(3) COD is almost completely removed in the anaerobic stage of the 1 ^# sequencing batch reactor, COD removal and nitrification are separated, and the effect of C/N ratio on biological nitrification is reduced. Under normal operation, 2 ^# sequencing batch reaction The organic content of the influent water is very low, which inhibits the growth of the aerobic bacteria and ensures the dominant flora status of the nitrifying bacteria.

(4) The double-mud biofilm denitrification simultaneous denitrification and dephosphorization reaction apparatus of the present invention has a good effect on COD, ammonia nitrogen and phosphorus, and effluent The COD is below 20 mg/l, the phosphorus is below 0.5 mg/l, and the ammonia nitrogen is below 3 mg/l.

DRAWINGS

1 is a schematic view showing the structure of a denitrification simultaneous denitrification and dephosphorization reaction apparatus for a double mud biofilm according to the present invention;

2 is a schematic diagram of a PLC program controller used in the present invention;

3 is a schematic diagram showing the removal effect of COD _Gr by a denitrification simultaneous denitrification and phosphorus removal reaction device of a double mud biofilm;

Figure 4 is a schematic view showing the removal effect of ammonia nitrogen by denitrification simultaneous denitrification and dephosphorization reaction equipment of double mud biofilm;

Figure 5 is a schematic view showing the removal effect of P on the denitrification and simultaneous nitrogen and phosphorus removal reaction equipment of the double mud biofilm;

Fig. 6 is a schematic diagram showing the variation of water quality in a typical operation cycle of a dual-mud biofilm denitrification simultaneous denitrification and dephosphorization reaction equipment.

detailed description

The invention is further described in the following with reference to the drawings and embodiments of the invention, but the scope of the invention is not limited to the scope described in the specific embodiments.

As shown in Fig. 1, the denitrification and denitrification and dephosphorization reaction equipment of the double mud biofilm includes 1 ^#

sequencing batch reactor

2, 2 ^# sequencing batch reactor 5 and nitrate exchanger 9; 1 ^# sequencing batch reaction The tank 2 is connected to the first feed water pump 1 through a pipe, and is also in communication with the nitrate exchanger 9 through the first drain valve 11; the nitrate exchanger 9 is connected to the 1 ^# sequencing batch reactor 2 through the feed pump third 7 and The second feed pump 4 is connected to the 2 ^# sequencing batch reactor 5 via the feed water pump, and the 2 ^# sequencing batch reactor 5 is also in communication with the nitrate exchanger 9 via the second drain valve 12. The 1 ^# sequencing batch reactor 2 is connected to the second blower 8 through a vent pipe, and the second blower 8 is blasted to the 1 ^# sequencing batch reactor 2 by aeration. 1 ^# sequencing batch reactor 2 is equipped with a stirrer 3 at the top, and the mixture in the 1 ^# sequencing batch reactor 2 is stirred in the anaerobic and anoxic section. The 2 ^# sequencing batch reactor 5 is connected to the first blower 6 through a vent pipe, and the first blower 6 is blasted to the 2 ^# sequencing batch reactor 5 by aeration. The 1 ^# sequencing batch reactor 2 is drained to the outside through the drain valve 13. Two constant temperature water baths are arranged in the vicinity of the reaction device, and the constant temperature water is separately sent to the intermediate connection of the double-layer cylinders of the 1 ^# sequencing batch reactor 2 and the 2 ^# sequencing batch reactor 5 through pipes. The programmable controller 10 is connected to the first inlet pump 1, the second inlet pump 4, the third inlet pump 7, the first blower 6, the agitator 3, and the blower second 8 through wires, and controls the water inlet, the drainage, and the blast. Start time and end time of aeration and agitation. The programmable controller 10 can be selected as a V80 series programmable controller. Its main function is: the controller reads the signals of different input devices (such as various switches and sensors) through the input interface (I/O), and executes the memory stored in the memory. Ladder program and send the result to the output device (such as solenoid valve, pump, etc.) through the output interface (I/O).

As a specific example, the 1 ^# sequencing batch reactor 2 is a plexiglass container, and the upper part is a double-layer plexiglass cylinder with an outer diameter of 22 cm, an inner diameter of 20 cm, and a height of 55 cm. The lower part is a truncated cone shape with a height of 10 cm, an upper diameter of 20 cm and a lower diameter of 5 cm. In the vertical direction of the outer wall of the cylindrical part of the reactor, an outlet is provided every 10 cm from the bottom of the cylinder for a total of 5 samples for sampling; on the other side of the sampling port, an outlet is provided every 4 cm from the bottom of the cylinder, for a total of 4 For drainage. There is an outlet at the bottom of the round table for emptying. All outlets are connected to a 15 cm diameter valve. 2 ^# sequencing batch reactor 5 is a plexiglass container, the upper part is a double-layer plexiglass cylinder, the outer diameter is 22cm, the inner diameter is 20cm, and the height is 55cm. The lower part is a truncated cone shape with a height of 10 cm, an upper diameter of 20 cm and a lower diameter of 5 cm. In the vertical direction of the outer wall of the cylindrical part of the reactor, an outlet is provided every 10 cm from the bottom of the cylinder for a total of 5 samples for sampling; on the other side of the sampling port, an outlet is provided every 4 cm from the bottom of the cylinder, for a total of 4 For drainage. There is an outlet at the bottom of the round table for emptying. All outlets are connected to a 15 cm diameter valve. The nitrate exchanger 9 is a barrel-shaped container with two inlets and two outlets, which are connected to the 1 ^#

sequencing batch reactor

2, 2 ^# sequencing batch reactor 5 through a pipeline.

The specific process includes the following steps:

(1) Anaerobic section: raw water is added to the 1 ^# sequencing batch reactor by feed pump 1 and anaerobic agitation, denitrifying phosphorus removal bacteria absorb a large amount of organic substrate and are in the form of PHB (intracellular poly-β-hydroxybutyl) Stored in the body, while releasing a large amount of phosphorus; then 1 ^# sequencing batch reactor sedimentation drainage: mud water separation, the ammonia-rich and phosphorus-rich supernatant is discharged from the 1 ^# sequencing batch reactor to the nitrate exchanger;

(2) aerobic section: the water rich in ammonia nitrogen and phosphorus in the nitrate exchanger is added to the 2 ^# sequencing batch reactor by the second feed water pump 4, and the nitrification reaction is carried out by aeration in the 2 ^# sequencing batch reactor. NH ₄ ⁺ -N is all converted to NO ₃ ^- -N; then 2 ^# sequencing batch reactor precipitation drainage: the above NO ₃ ^- -N-rich nitrification liquid is discharged to the nitrate exchanger; then 1 ^# sequencing batch The reactor is again filled with water: the above-mentioned nitrifying liquid is added back from the nitrate exchanger to the 1 ^# sequencing batch reactor with a third feed water pump 7;

(3) Anoxic section: The above 1 ^# sequencing batch reactor is under aerobic stirring, and the denitrifying phosphorus removal bacteria uses PHB as the electron donor in the body, and NO ₃ ^- -N provided by the 2 ^# sequencing batch reactor is the electron. The receptor simultaneously completes anoxic denitrification and denitrification and excessive phosphorus uptake.

(4) Aerobic section: 1 ^# sequencing batch reactor short-time stripping aeration to facilitate the removal of nitrogen and enhance the removal of phosphorus to prevent the 'secondary release' of phosphorus; 1 ^# sequencing batch reactor precipitation Drainage: The above 1 ^# sequencing batch reactor sedimentation drainage. In this way, the two reactors only exchange the supernatant during the reaction cycle and do not exchange the respective activated sludge to form a double mud system.

As shown in FIG. 2, the V80 series programmable controller controls the time of each process of anaerobic stirring, sedimentation, drainage, aeration, and aeration after the invention, and the opening of related operations. The specific process is as follows: The effective volume of the two sequencing batch reactors is 12L, the whole system design operation cycle is 12h, 9L synthetic wastewater is added at the beginning of each cycle, and the 1 ^# sequencing batch reactor is anaerobicly stirred for 140 min (including water inflow). 20 min), sedimentation for 35 min, separation of mud water, drainage for 15 min, the supernatant containing phosphorus and ammonia nitrogen is discharged into the nitrate exchanger; 2 ^# sequencing batch reactor from the nitrate exchanger for 20 min, blast Aeration for 200 min (including influent time), after aerobic end 2 ^# sequencing batch reactor reactor static precipitation for 35 min, the precipitated nitrification liquid is discharged into the nitrate exchanger, drainage time 15 min; 1 ^#序批The reactor reactor was stirred under oxygen for 200 min (containing 20 minutes into the nitrifying solution), a short aeration for 30 min, precipitation for 35 min, and finally the drain valve was opened, and 9 L of the supernatant was discharged from the reactor, and the drainage time was 15 min. . At the end of the aerobic end of the 1 ^# sequencing batch reactor, the muddy water mixture is used to control the sludge age of the 1 ^# sequencing batch reactor. The sludge age is controlled in about 10 days, and the 2 ^# sequencing batch reactor is not drained. The sludge concentration is between 2.2 and 2.5 g / L. The temperature in the reactor was controlled at about 30 ° C with a constant temperature water bath. The PLC programmable controller is used to automatically control the water inflow, aeration, agitation, sedimentation, drainage and other operations of the two sequencing batch reactors.

实施效果： Implementation Effect:

In the single mud biological nitrogen and phosphorus removal process, the phosphorus removal bacteria, denitrifying bacteria and nitrifying bacteria coexist in the same activated sludge system, and there must be different mud age disputes between the nitrifying bacteria and the phosphorus removal bacteria, so that phosphorus removal and Nitrification interferes with each other, and because nitrifying bacteria are autotrophic obligate aerobic microorganisms, denitrifying bacteria and dephosphorizing bacteria are heterotrophic facultative bacteria, and the system's A/A/O alternate operation is for both phosphorus removal and denitrification. It is advantageous, but it is not a suitable growth environment for nitrifying bacteria. According to the theory of denitrification, nitrogen and phosphorus removal, a double-fluid method SBR denitrification biological nitrogen and phosphorus removal process with long-term stable operation was designed. The nitrifying bacteria and denitrifying phosphorus removal bacteria (DPB) were separated in different sludge systems. Carry out cultivation, It can avoid the competition of denitrifying bacteria and DPB for organic matter in the traditional nitrogen and phosphorus removal process, and also avoid the difference of the sludge age of the two bacteria. SBR (sequential batch reactor) in double mud membrane method The minimum SRT required for nitrification in the denitrifying phosphorus removal and denitrification system is no longer a controlling factor for the denitrifying phosphorus removal process. The SRT can be changed according to actual requirements, and the optimal growth for nitrifying bacteria and DPB is created. surroundings, Thus, ideal nitrification and denitrifying phosphorus removal can be achieved.

The effect of the implementation of the present invention is divided into six stages, and the first stage is the trial operation stage; after 32 days of trial operation, after the system treatment effect is stable, the second stage is to reduce the mud age to 5 days to investigate the ultra-short mud age. The third stage is the system recovery stage. After 3 days of short mud age operation, the mud loss is more, the system returns to 10 days of mud age for 20 days; the fourth stage is after the system treatment effect is stable. The mud age was increased to 20 days to investigate the operation of the system; in the fifth stage, the COD concentration was reduced to 150 mg/L, and the effect of low C/N ratio on denitrifying phosphorus removal was investigated. The water temperature of the sixth stage 1 ^# sequencing batch reactor was about 17 °C, and the effect of low temperature on denitrifying phosphorus removal was investigated.

The influent uses artificially prepared synthetic wastewater. The main components are: 250 mgCOD/L NaAc, 0.028 g/L K ₂ HPO ₄ , 0.022 g/L KH ₂ PO ₄ , 0.115 g/L NH ₄ Cl, 0.035 g/LCaCl ₂ ּ2H ₂ O , 0.15 g / L MgSO ₄ ּ 7H ₂ O, 0.3 ml / L trace element solution. The trace element solution component is (1 L distilled water): 10 g EDTA, 1.5 g FeCl ₃ ּ 6H ₂ O , 0.15 g H ₃ BO ₃ , 0.03 g CuSO ₄ ּ 5H ₂ O , 0.18 g KI, 0.12 g MnCl ₂ ּ 4H ₂ O , 0.06 g NaMoO ₄ ּ 2H ₂ O , 0.12 g of ZnSO ₄ ּ7H ₂ O , 0.15 g of CoCl ₂ ּ6H ₂ O . The test inoculation sludge was taken from a sewage treatment plant in Guangzhou.

Analytical method: COD: XJ-1 type COD digestion apparatus digestion, potassium dichromate method; TP: molybdenum rhenium anti-spectrophotometry; NH ₄ ⁺ -N: Nessler reagent spectrophotometry; NO ₂ ^- -N: N-( 1-naphthyl)-ethylenediamine spectrophotometry; NO ₃ ^- -N: ultraviolet spectrophotometry.

1, COD removal effect

As can be seen from Figure 3, the double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment for COD Has a good processing effect. For simulated domestic sewage (formed from sodium acetate), the system's COD removal is generally stable, and the effluent COD is basically 20 mg/L. Below, the national emission standards are met. The fluctuation of the effluent concentration is small, and the removal rate is basically above 90%. However, when the sludge age is controlled at 5 days (the second stage), the COD removal rate is only 70%. Left and right, this is due to the daily mud discharge amount of up to 2.4L, there is not enough microbial degradation COD . Different from the traditional removal method of organic matter in the denitrification and dephosphorization process, most of the organic matter in the double mud system is consumed by the denitrifying phosphorus removal bacteria in the anaerobic tank for synthesizing the storage particles PHB and releasing phosphorus in the cells.

2, ammonia nitrogen removal

As shown in Figure 4, the influent ammonia nitrogen is about 30 mg/L, and the effluent ammonia nitrogen is maintained at a relatively low level, basically less than 3 mg/L, and the ammonia nitrogen removal rate is above 90%. This is because the nitrification reaction of the double mud process is carried out in a 2 ^# sequencing batch biofilm reactor supported by a fiber filler. The fiber filler has a large specific surface area and a good film-hanging effect, ensuring stable nitrification performance. Since only 75% of the raw water in the 1 ^# sequencing batch reactor is exchanged into the 2 ^# sequencing batch biofilm reactor after the anaerobic phosphorus release, the exchange rate of water is 75%, so it is not the 1 ^# sequencing batch reaction. All of the ammonia nitrogen in the plant can be nitrated, and some ammonia nitrogen remains. This part of the ammonia nitrogen is oxidized to nitrate or nitrous oxide during 30 minutes of aerobic ablative aeration. Therefore, the ammonia nitrogen removal rate is high during the whole operation period. Above 90%, the effluent ammonia nitrogen is maintained at a relatively low level, which is basically less than 3 mg/L.

3, P removal

It can be seen from Figure 5 that the phosphorus removal rate reaches 95% on the 8th day of operation, and the effluent phosphorus content is lower than 0.5 mg/L. During the rest of the first stage, the phosphorus content of the effluent is basically maintained below 0.5 mg/L, and the phosphorus removal effect is good. In the second stage, the mud age was reduced to 5 days, and the phosphorus removal rate was found to be as high as 98.56 %, but The COD removal rate is very low, and in the second period of the second stage, the phosphorus removal rate is also decreasing, and the sludge is obviously thinned. This may be excessive sludge discharge, and the loss of phosphorus removal bacteria in the sludge is large, MLSS Caused by lower concentrations. In the third stage, the mud age recovered to about 10 days. After 20 days of operation, the phosphorus removal effect was stabilized, and the SRT was increased to 20 days. The phosphorus removal rate was rapidly reduced to 50%. Left and right, the effluent phosphorus content is very high. This is because the amount of sludge is too small, and the phosphorus-containing sludge remains in the reactor, which does not achieve the purpose of removing phosphorus. It can be seen that SRT is very important to ensure the efficient and stable operation of the system. The double-mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment SRT is maintained for about 10 days, which can ensure that the system has sufficient sludge volume, and can ensure that the phosphorus removal effect of the system will not be affected after sludge discharge.

It can also be seen from Figure 5 that the phosphorus removal rate of the fifth stage with a lower COD concentration is significantly lower than the first and third stages. This is because when the concentration of COD in stage 5 is reduced to 150 mg/L, the VFA content of the system is small, and the amount of anaerobic phosphorus is also small, so that there will be a large amount of NO ₃ ^- -N residues at the end of the anoxic section. The NO ₃ ^- -N will seriously affect the anaerobic phosphorus release effect in the next cycle, so too low COD is not conducive to phosphorus removal. The effect of temperature on denitrifying phosphorus removal can also be seen from Figure 5. In the sixth stage with a temperature of only about 17 °C, the phosphorus removal rate is 59.43%-76.42%, and the general bias is lower than the fifth stage of 77.12%-85.49%. Therefore, the double-mud biofilm denitrification simultaneous denitrification and dephosphorization reaction equipment operates under low temperature conditions, and it is necessary to appropriately prolong the time of oxygen deficiency and phosphorus uptake.

4, double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment operation cycle water quality analysis

Figure 6 is a double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment Water quality changes during a typical operating cycle monitored after stable operation.

(1) Anaerobic section

It can be seen from Fig. 6 that the concentration of ammonia nitrogen does not change much during the whole anaerobic section, and this part of ammonia nitrogen consumption is needed for microbial growth and reproduction. The nitrate nitrogen remaining in the reactor after the end of the aerobic section in the last cycle was quickly denitrified in the early stage of anaerobic treatment. The COD in the sewage is rapidly adsorbed and degraded in the anaerobic section, and the removal rate is as high as 96.8 %. In fact, the COD removal rate in the water reaches 80% after anaerobic adsorption for about 95 minutes. Along with the removal of COD in the water, anaerobic phosphorus release occurs in the reactor, and the rate of phosphorus release corresponds to the removal rate of COD in the water. At the beginning of 80 min, the phosphorus content in the mixture has reached 20.276 mg/L. The release of phosphorus and the rate of degradation of COD are then slowed down. Since most of the organic matter in the influent is removed under anaerobic conditions, the organic matter is most likely to be used for anaerobic phosphorus release and synthesis of the internal carbon source PHB required for subsequent anoxic denitrification phosphorus and nitrogen removal, thereby improving organic matter. The utilization rate in biological nitrogen and phosphorus absorption is avoided by other bacteria in the aerobic phase. Moreover, COD is directly removed as an anaerobic product without oxidation, which saves aeration compared to conventional activated sludge processes. Since the organic matter in the influent water is almost completely removed under anaerobic conditions, it provides a low C/N ratio of water for the nitrification of the next 2 ^# sequencing batch biofilm reactor, ensuring 2 ^# sequencing batch biofilm The dominant position of nitrifying bacteria in the reactor lays the foundation for efficient nitrification.

(2) Aerobic section

Figure 6 shows that aerobic nitrification occurred in the 2 ^# sequencing batch biofilm reactor, the ammonia nitrogen in the water was rapidly nitrated, and the concentration of NO ₃ ^- -N was greatly increased, and the NO ₂ ^- -N concentration was also increased. . Since the 2 ^# sequencing batch biofilm reactor has been in aerobic nitrification state, and the COD content in the water is very low, no sludge is discharged, which is not conducive to the growth of phosphorus removal bacteria. Therefore, the content of P remains basically unchanged throughout the nitrification stage. . According to the cycle water quality change chart, the 2 ^# sequencing batch biofilm reactor is a good biological nitrification system, and its good performance depends on the operating conditions designed for the 2 ^# sequencing batch biofilm reactor: complete aerobic; Super long mud age; basically no COD compliance.

(3) anoxic section

It can be seen from Fig. 6 that the concentration of NO ₃ ^- -N in the anoxic zone drops sharply, accompanied by the rapid absorption of phosphorus, that is to say, denitrifying phosphorus removal occurs in the anoxic section, and the denitrifying phosphorus removal bacteria pass through. The anaerobic section fully releases phosphorus and absorbs rapidly degrading organic matter to synthesize a large amount of PHB. After entering the anoxic zone, nitrate is used as the PHB of the final electron acceptor hypoxic respiratory decomposition bacteria, which generates a large amount of energy for phosphorus absorption and phosphorus accumulation. Synthesis. The rate of denitrification and dephosphorization also showed a trend of first fast and then slow. At the end of the anoxic phase, the concentration of P decreased from 24.897 mg/L at the beginning of hypoxia to 1.69 mg/L, and the corresponding concentration of NO ₃ ^- -N decreased from 22.643 mg/L to 0.568 mg/L. There is almost no change in the concentration of ammonia nitrogen remaining in the sewage.

(4) Stripping the aeration section

After entering the aerobic stripping aeration stage, aerobic phosphorus uptake occurred in the reactor, and the P concentration decreased from 1.69 mg/L to 0.478 mg/L. The residual ammonia nitrogen in the water was rapidly nitrated during aerobic period of 30 min. The ammonia nitrogen concentration decreased from 5.847 mg/L to 1.574 mg/L, and the NO ₃ ^- -N concentration increased to 3.526 mg/L.

Claims

1 , double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction equipment, characterized by comprising a 1 ^# sequencing batch reactor (2), 2 ^# sequencing batch reactor (5) and a nitrate exchanger (9); The 1 ^# sequencing batch reactor ( 2 ) is connected to the first feed water pump ( 1 ) through a pipe, and is also connected to the nitrate exchanger ( 9 ) through the first drain valve ( 11 ); the nitrate exchanger ( 9 ) passes the first Three pumps (7) with a ^# sequencing batch reactor (2) is connected, is also connected via a second feed pump (4) and the 2 ^# sequencing batch reactor (5), 2 ^# sequencing batch reactor (5 And communicating with the nitrate exchanger (9) through the second drain valve (12); the second blower is respectively disposed in the 1 ^# sequencing batch reactor (2) and the 2 ^# sequencing batch reactor (5) (8) and the first blower (6).

The double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction apparatus according to claim 1, characterized in that the 1 ^# sequencing batch reactor (2) is further provided with a stirrer (3).

3 . The double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction device according to claim 1 , wherein the 1 ^# sequencing batch reactor and the 2 ^# sequencing batch reactor are double-layered cylindrical structures, A cavity for holding hot water is arranged in the middle, and the constant temperature water bath is connected to the intermediate cavity of the double-layer cylinder of the 1 ^# sequencing batch reactor and the 2 ^# sequencing batch reactor through pipes.

4 . The double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction device according to claim 1 , wherein the device further comprises a PLC programmable controller. (10) The programmable controller (10) is respectively associated with the first inlet pump (1), the second inlet pump (4), the third inlet pump (7), the first blower (6), and the first drain valve ( 11), the second drain valve (12), the agitator (3) and the second blower (8) are connected.

The double mud biofilm denitrification simultaneous nitrogen and phosphorus removal reaction apparatus according to claim 1, characterized in that the 1 ^# sequencing batch reactor (2) or the 2 ^# sequencing batch reactor is prepared by plexiglass. .