CN110668566A - Device and method for sludge reduction and total nitrogen removal by sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonia oxidation - Google Patents

Abstract

A device and method for sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonium oxidation to realize sludge reduction and total nitrogen removal belong to the field of sewage biological treatment. The device includes a raw water tank, a sludge storage tank, a nitrifying liquid water tank, an intermediate water tank, two SBR reactors, and a water outlet tank. The excess sludge enters the sludge fermentation coupled short-range denitrification reactor, and the refractory organic matter in the sludge is converted into easily degradable organic matter through fermentation; then the nitrification solution enters the sludge fermentation coupled with the short-range denitrification reactor, and the fermentation product is used as the carbon source reaction to complete the accumulation of nitrous; finally, the effluent from the reactor and the domestic sewage enter the anammox biofilm reactor to achieve total nitrogen removal. The method combines sludge fermentation coupled with short-range denitrification and anammox in series, which not only reduces the cost of sludge disposal, but also saves carbon sources, and provides more suitable living conditions for anammox bacteria, thereby realizing sludge disposal. Reduction and total nitrogen removal.

Description

Sludge fermentation coupled with short-range denitrification in series with two-stage anammox to achieve sludge reduction Apparatus and method for removing total nitrogen

technical field

The invention relates to a device and method for synchronously realizing sludge reduction and total nitrogen removal by coupling with short-range denitrification and series two-stage anaerobic ammonia oxidation, belonging to the technical field of sewage biological treatment, and is a method for realizing the harmless reduction of excess sludge. A test device and method for simultaneously realizing total nitrogen removal.

Background technique

With the development of industry and the improvement of living standards of residents, nutrients such as nitrogen and phosphorus in the water body have increased, and eutrophication problems have occurred frequently. Phosphorus in water can be removed by various methods such as biological adsorption and chemical sedimentation, while nitrogen can only be removed from water by redoxing combined nitrogen to nitrogen through nitrogen cycle. Therefore, it is particularly important to explore new denitrification processes.

Among them, anammox process is favored by most scholars due to its high efficiency, economy and good energy saving effect. Compared with traditional nitrification and denitrification, short-path nitrification coupled with anammox can save 58.6% of aeration and 100% of carbon sources, while short-path denitrification coupled with anammox can save 44.9% of aeration and 73% of carbon sources. carbon source.

There are still some obstacles in the realization of anammox in engineering, such as the difficulty of enrichment of anammox bacteria, the weaker competitiveness of anammox bacteria for nitrite than NOB, and the large amount of urban sewage treatment water. Compared with the short-path nitrification process, the short-path denitrification avoids the competition of NOB for nitrite, and has the advantages of strong stability and not easy to be destroyed. However, the short-range denitrifying bacteria have strong selectivity to carbon sources, and the enrichment is difficult, and the enriched short-range denitrifying bacteria can utilize easily degradable organic matter, but cannot utilize refractory organic matter. The research shows that the conversion of refractory organic matter to easily degradable organic matter can be realized by hydrolysis and acidification technology.

The urban sewage treatment plants discharge a large amount of excess sludge every day, and the treatment and disposal costs are high. At the same time, if the treatment is improper, it will become another form of pollution. And most of the current urban sewage has low C/N, which makes it necessary to add a carbon source in the traditional denitrification process, and the excess sludge is a complex form of carbon source, and the hydrolyzed product of the excess sludge can be used as organic carbon. This method not only realizes the reduction of excess sludge but also saves carbon sources.

The composition of active microorganisms in excess sludge is different, which has a certain impact on the reaction system. Therefore, certain technical means can be used for pretreatment to reduce the activity of excess sludge and reduce the impact on short-range denitrification. At present, the methods of sludge pretreatment include physical method and chemical method. The physical method includes ultrasonic, thermal hydrolysis, mechanical pulverization, etc. The chemical method is mainly based on the addition of chemicals. Compared with chemical methods, physical methods are simpler, safer and easier to control.

If the technical control is based on the above means, it is expected to realize sludge fermentation coupled with short-range denitrification to realize the conversion of sludge reduction and the stable accumulation of nitrite.

The yield coefficient of denitrifying bacteria is 0.3g VSS/g NH ₄ ⁺ -N, while the yield coefficient of anammox bacteria is only 0.066gVSS/g NH ₄ ⁺ -N, so the growth rate of denitrifying bacteria is much higher Due to the growth rate of anammox bacteria, both bacteria can use nitrite as a substrate to generate nitrogen gas, so when there is sufficient organic matter and nitrate or nitrite in the system, denitrifying bacteria gradually become dominant bacteria. The number of anammox bacteria gradually decreased. The competition between the two species can be resolved by working separately.

Sludge fermentation coupled with short-range denitrification and tandem anammox process: On the one hand, sludge fermentation coupled with short-range denitrification can be realized in one SBR reactor, and short-range denitrification and sludge reduction can be accomplished at the same time on the basis of no external carbon source. . By adding the activated sludge of hydrolysis and acidification coupled with short-range denitrification into the SBR reactor, the process of sludge fermentation coupled with short-range denitrification can be realized during the reaction process. In the process of sludge fermentation, easily degradable organic matter is produced to provide carbon source for short-range denitrification, thereby realizing the accumulation of nitrite. At the same time, the hydrolyzate of the excess sludge is used as an organic carbon source to help realize the denitrification process. This method not only realizes the reduction of the excess sludge but also saves the carbon source.

On the other hand, anammox denitrification is achieved in an SBBR reactor. By adding biofilm packing enriched with anammox bacteria into the SBBR reactor, the attached growth of anammox bacteria can be realized and the biomass of anammox bacteria can be maintained. The nitrite in the drainage of the SBR reactor and the ammonia nitrogen in the domestic sewage undergo an anaerobic ammonium oxidation reaction, and the remaining nitrite can be denitrified by a small amount of denitrifying bacteria carried by the domestic sewage using the organic matter in it. Total nitrogen removal.

The tandem process is not only simple in process, but also has the respective advantages of anaerobic ammonia oxidation, sludge fermentation, short-range denitrification and other processes, and simultaneously realizes sludge reduction and total nitrogen removal.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a device and method for a first-stage sludge fermentation coupled with a short-range denitrification and a series of two-stage anammox processes, so as to provide a carbon source, generate and accumulate nitrite nitrogen through sludge fermentation. Accumulation, reducing excess sludge and saving carbon sources, and then anaerobic ammonia oxidation in series to achieve total nitrogen removal.

The object of the present invention is to be solved by the following technical solutions: a device and method for realizing sludge reduction and total nitrogen removal by first-stage sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonium oxidation, characterized in that it includes municipal sewage Raw water tank (1), sludge mixed liquid storage tank (2), nitrification liquid tank (3), sludge fermentation coupled short-range denitrification reactor (4), intermediate water tank (5), anammox biofilm reactor (6), the water outlet tank (7).

The sludge mixed liquor storage tank (2) is provided with a stirring device III (2.1); the sludge fermentation coupled short-range denitrification reactor (4) is provided with a built-in sludge feed pump (4.1), feed pump I (4.2), Drainage electric valve I (4.3), stirring device I (4.4), DO online detector I (4.5), first sampling port (4.6), second sampling port (4.7); the anammox biofilm reactor (6) Built-in inlet water pump II (6.1), intermediate water tank water pump (6.2), electric drain valve II (6.3), stirring device II (6.4), DO online detector II (6.5), packing and packing frame (6.6), A sampling port (6.7); the water outlet tank (7) is provided with an overflow pipe (7.1) and a drain pipe (7.2).

Wherein, the sludge mixed liquid storage tank (2) is connected with the sludge fermentation coupled short-range denitrification reactor (4) through the sludge feed pump (4.1); The sludge fermentation is coupled with the short-range denitrification reactor (4); the sludge fermentation is coupled with the short-range denitrification reactor (4), and the drain electric valve I (4.3) is connected with the intermediate water tank (5); the intermediate water tank (5) passes through the intermediate water tank The water pump (6.2) is connected with the anammox biofilm reactor (6); the urban sewage raw water tank (1) is connected with the anammox biofilm reactor (6) through the feed pump II (6.1); The electric drain valve II (6.3) of the ammonia oxidation biofilm reactor (6) is connected with the water outlet tank (7).

The present invention also provides a method for the first-level sludge fermentation coupled with short-range denitrification in series with the second-level anaerobic ammonium oxidation, and the specific start-up and control steps are as follows:

1) System start-up: Add hydrolysis acidification coupled short-range denitrification sludge to the sludge fermentation coupled short-range denitrification reactor (4), so that the sludge concentration in the reactor after inoculation reaches 2000-6000 mg/L (with the reactor Effective volume meter); add the biofilm packing enriched with anammox bacteria into the anammox biofilm reactor (6), so that the biofilm packing of anammox bacteria accounts for the anammox biofilm 20% to 80% of the effective volume of the reactor (6).

2) Determination of the amount of excess sludge, nitrification solution, raw water and intermediate nitrite solution:

Take the remaining sludge and ferment it at 30 degrees Celsius. By measuring the SCOD concentration, when the SCOD concentration has no increasing trend and the SCOD value does not increase within 20 minutes, it is the maximum potential of sludge fermentation at this concentration.

In the sludge fermentation coupled short-range denitrification reactor (4), the organic matter and nitrate feeds are determined according to the calculation formulas (1) and (2):

V ₁ +V ₂ =V·P ₁ (2)

Note: SCOD in the formula is the SCOD concentration under the maximum fermentation potential of the excess sludge;

V ₁ , V ₂ , V are the organic matter feed, the nitrate solution feed and the effective volume of the reactor, respectively

NO ₃ ^- is the influent nitrate concentration;

C/N is the set value, and the value can be arbitrarily selected within the range of 3:1 to 6:1;

P ₁ is the drainage ratio, the set value, which is 60%.

In the anammox biofilm reactor (6), according to the calculation formula (3) (4), determine the raw water and intermediate water tank water inflow:

V ₃ +V ₄ =V·P ₂ (4)

Note: in the formula NO ₂ ^- is the NO ₂ ^- concentration in the intermediate water tank, NH ₄ ^+- is the raw water NH ₄ ⁺ concentration;

V ₃ , V ₄ , and V are the NO ₂ ^- solution feed, the NH ₄ ⁺ solution feed and the effective volume of the reactor, respectively;

P ₂ is the drainage ratio, the set value, which is 50%;

NO ₂ ^- /NH ₄ ⁺ is the set ratio, and the value can be arbitrarily selected within the range of 1.4:1 to 2:1.

3) The adjustment operation at runtime is as follows:

Add the excess sludge to the sludge mixed liquid storage tank (1), start the agitator (1.1) before the start of each cycle to mix the excess sludge evenly, and then start the sludge feed pump (4.1), at the beginning of each cycle V ₁ volume of excess sludge mixed solution is pumped into the sludge fermentation coupled short-range denitrification reactor (4) to carry out sludge fermentation;

When the sludge fermentation is coupled with the short-range denitrification reactor (4), anaerobic stirring is performed for 200-800 minutes in each cycle, and the anaerobic stirring is terminated when the SCOD value reaches more than 95% of the maximum fermentation potential; The nitrifying liquid in the nitrifying liquid tank ( ₃ ) is pumped into the sludge fermentation coupled short-path denitrification reactor (4), so that the nitrate nitrogen concentration in the sludge fermentation coupling short-path denitrification reactor (4) is set to Concentration, set the concentration to meet the C/N ratio of 3:1 to 6:1; stir in anoxic until the nitrite conversion rate reaches more than 80% or the nitrate concentration is less than 3mg/L, then stop stirring and start precipitation and drainage for 10 minutes, idle Then enter the next cycle.

After the sludge fermentation coupled with the short-range denitrification reactor (4) drains the water, the intermediate water tank water pump (6.2) is started to pump the nitrification solution of the intermediate water tank V ₃ volume into the anammox biofilm reactor (6), and at the same time the Pump II (6.1) pumps _V4 volume of raw urban sewage into the anaerobic ammonia oxidation biofilm reactor (6), so that the ratio of nitrite to ammonia nitrogen meets the set value, and the set value is 1.4:1～ Anything within the range of 2:1; anoxic stirring until the total inorganic nitrogen concentration is lower than 5mg/L, stop stirring, precipitate and drain for 10 minutes, and enter the next cycle after being idle.

The device and method for sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonia oxidation to realize sludge reduction and total nitrogen removal of the present invention have the following advantages:

1) Through the sludge fermentation technology, the weight reduction of the excess activated sludge is realized, the excess sludge is recycled, the addition of external carbon sources is reduced, and the cost of sludge disposal is saved.

2) Through condition control, the stable accumulation of nitrite can be achieved, which can provide a substrate source for the secondary anammox process, and provide a good reference for the realization and process control of the short-range denitrification process.

3) Realize sludge fermentation coupled with short-range denitrification in the same reactor, in order to realize the easy degradation of excess sludge, convert it into easily degradable organic matter, and provide easily degradable carbon source for short-range denitrification bacteria, and in the process without external carbon source Accumulation of nitrite in short-range denitrification can be realized under the condition of energy saving.

4) This process device is a two-stage series device. The first-stage reactor is used for sludge fermentation and short-range denitrification, and the second-stage reactor is used for anammox. This design avoids competition between denitrifying bacteria and anammox bacteria for substrates. At the same time, it can provide better reaction conditions for anammox bacteria, which is more conducive to the occurrence of anammox reaction.

Description of drawings

Figure 1 is a schematic diagram of the structure of the sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonium oxidation to achieve sludge reduction and total nitrogen removal.

In the figure, 1 is the urban sewage raw water tank, 2 is the sludge mixed liquid storage tank, 3 is the nitrification liquid tank, 4 is the sludge fermentation coupled short-range denitrification reactor, 5 is the intermediate water tank, and 6 is the anammox biofilm reaction. 7 is the water outlet tank; 2.1 is the stirring device III; 4.1 is the mud pump, 4.2 is the intake pump I, 4.3 is the drain electric valve I, 4.4 is the stirring device I, 4.5 is the DO online detector I, and 4.6 is the first Sampling port, 4.7 is the second sampling port; 6.1 is the inlet water pump II, 6.2 is the intermediate water tank water pump, 6.3 is the electric drain valve II, 6.4 is the stirring device II, 6.5 is the DO online detector II, 6.6 is the packing and packing frame, 6.7 is the sampling port; 7.1 is the overflow pipe of the water outlet, and 7.2 is the drain pipe of the water outlet.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and Examples: as shown in Figure 1, the single sludge fermentation coupled with short-range denitrification realizes the conversion of particulate refractory organic matter and the device and method for the accumulation of nitrite, characterized in that, Including urban sewage raw water tank (1), sludge mixed liquid storage tank (2), nitrification liquid tank (3), sludge fermentation coupled short-range denitrification reactor (4), intermediate water tank (5), anammox biological Membrane reactor (6), outlet water tank (7).

The sludge mixed liquor storage tank (2) is provided with a stirring device III (2.1); the sludge fermentation coupled short-range denitrification reactor (4) is provided with a built-in sludge feed pump (4.1), feed pump I (4.2), Drainage electric valve I (4.3), stirring device I (4.4), DO online detector I (4.5), first sampling port (4.6), second sampling port (4.7); the anammox biofilm reactor (6) Built-in inlet water pump II (6.1), intermediate water tank water pump (6.2), electric drain valve II (6.3), stirring device II (6.4), DO online detector II (6.5), packing and packing frame (6.6), A sampling port (6.7); the water outlet tank (7) is provided with an overflow pipe (7.1) and a drain pipe (7.2).

Wherein, the sludge mixed liquid storage tank (2) is connected with the sludge fermentation coupled short-range denitrification reactor (4) through the sludge feed pump (4.1); The sludge fermentation is coupled with the short-range denitrification reactor (4); the sludge fermentation is coupled with the short-range denitrification reactor (4), and the drain electric valve I (4.3) is connected with the intermediate water tank (5); the intermediate water tank (5) passes through the intermediate water tank The water pump (6.2) is connected with the anammox biofilm reactor (6); the urban sewage raw water tank (1) is connected with the anammox biofilm reactor (6) through the feed pump II (6.1); The electric drain valve II (6.3) of the ammonia oxidation biofilm reactor (6) is connected with the water outlet tank (7).

During the test, the specific experimental water was taken from the domestic sewage and the family area of Beijing University of Technology. The specific water quality is as follows: COD concentration is 178-298 mg/L, NH ₄ ⁺ -N concentration is 45-71 mg/L, NO ₂ ^- -N Concentration＜1mg/L, NO ₃ ^- -N concentration 0.1～1.4mg/L, PO ₄ ^3- -P concentration 4.3～7.6mg/L, pH value 7.3～7.6. Sludge Fermentation The excess sludge is taken from the sludge of the pilot-scale secondary sedimentation tank of Beijing University of Technology, which is inactivated by a physical method and then added to the sludge storage tank (1). The nitrification solution is the effluent of the laboratory nitrification reactor or the nitrate wastewater, and the NO ₃ ^- -N concentration after mixing is 10-50 mg/L. The test system is shown in Figure 1. The reactor is made of plexiglass, and the effective volume of the sludge fermentation coupled with the short-range denitrification reactor (4) and the anammox biofilm reactor (6) is 10L.

The specific operation is as follows:

1) System start-up: Add hydrolysis acidification coupled short-range denitrification sludge to the sludge fermentation coupled short-range denitrification reactor (4), so that the sludge concentration in the reactor after inoculation reaches 2000-6000 mg/L (with the reactor Effective volume meter); add the biofilm packing enriched with anammox bacteria into the anammox biofilm reactor (6), so that the biofilm packing of anammox bacteria accounts for the anammox biofilm 20% to 80% of the effective volume of the reactor (6).

2) Determination of the amount of excess sludge, nitrification solution, raw water and intermediate nitrite solution:

Take the remaining sludge and ferment it at 30 degrees Celsius. By measuring the SCOD concentration, when the SCOD concentration has no increasing trend and the SCOD value does not increase within 20 minutes, it is the maximum potential of sludge fermentation at this concentration.

In the sludge fermentation coupled short-range denitrification reactor (4), the organic matter and nitrate feeds are determined according to the calculation formulas (1) and (2):

V ₁ +V ₂ =V·P ₁ (2)

Note: SCOD in the formula is the SCOD concentration under the maximum fermentation potential of the excess sludge;

V ₁ , V ₂ , V are the organic matter feed, the nitrate solution feed and the effective volume of the reactor, respectively

NO ₃ ^- is the influent nitrate concentration;

C/N is the set value, and the value can be arbitrarily selected within the range of 3:1 to 6:1;

P ₁ is the drainage ratio, the set value, which is 60%.

In the anammox biofilm reactor (6), according to the calculation formula (3) (4), determine the raw water and intermediate water tank water inflow:

V ₃ +V ₄ =V·P ₂ (4)

Note: in the formula NO ₂ ^- is the NO ₂ ^- concentration in the intermediate water tank, NH ₄ ^+- is the raw water NH ₄ ⁺ concentration;

V ₃ , V ₄ , and V are the NO ₂ ^- solution feed, the NH ₄ ⁺ solution feed and the effective volume of the reactor, respectively;

P ₂ is the drainage ratio, the set value, which is 50%;

NO ₂ ^- /NH ₄ ⁺ is the set ratio, and the value can be arbitrarily selected within the range of 1.4:1 to 2:1.

3) The adjustment operation at runtime is as follows:

Add the excess sludge to the sludge mixed liquid storage tank (1), start the agitator (1.1) before the start of each cycle to mix the excess sludge evenly, and then start the sludge feed pump (4.1), at the beginning of each cycle, the V ₁ volume of excess sludge mixed solution is pumped into the sludge fermentation coupled short-range denitrification reactor (4) to carry out sludge fermentation;

When the sludge fermentation is coupled with the short-range denitrification reactor (4), anaerobic stirring is performed for 200-800 minutes in each cycle, and the anaerobic stirring is terminated when the SCOD value reaches more than 95% of the maximum fermentation potential; The nitrifying liquid in the nitrifying liquid tank ( ₃ ) is pumped into the sludge fermentation coupled short-path denitrification reactor (4), so that the nitrate nitrogen concentration in the sludge fermentation coupling short-path denitrification reactor (4) is set to Concentration, set the concentration to meet the C/N ratio of 3:1 to 6:1; stir in anoxic until the nitrite conversion rate reaches more than 80% or the nitrate concentration is less than 3mg/L, then stop stirring and start precipitation and drainage for 10 minutes, idle Then enter the next cycle.

After the sludge fermentation coupled with the short-range denitrification reactor (4) drains the water, the intermediate water tank water pump (6.2) is started to pump the nitrification solution of the intermediate water tank V ₃ volume into the anammox biofilm reactor (6), and at the same time the Pump II (6.1) pumps _V4 volume of raw urban sewage into the anaerobic ammonia oxidation biofilm reactor (6), so that the ratio of nitrite to ammonia nitrogen meets the set value, and the set value is 1.4:1～ Anything within the range of 2:1; anoxic stirring until the total inorganic nitrogen concentration is lower than 5mg/L, stop stirring, precipitate and drain for 10 minutes, and enter the next cycle after being idle.

The experimental results show that the residual sludge after pretreatment can be converted into easily degradable organic matter in the sludge fermentation stage. As a carbon source for short-range denitrification, the sludge reduction effect can reach 50% to 70%; Nitrate accumulation, the accumulation rate is 60% to 80%, and the concentration of nitrate nitrogen in the effluent is negligible; in the anammox stage, the anammox bacteria can convert all ammonia nitrogen into nitrogen, and the remaining nitrous can be denitrifying bacteria. The organic matter in the domestic sewage is reduced to nitrogen, and the total nitrogen in the effluent is less than 5mg/L.

Claims (2)

1. A device for sludge fermentation coupled with short-range denitrification in series with two-stage anaerobic ammonium oxidation to realize sludge reduction and total nitrogen removal, characterized in that it comprises an urban sewage raw water tank (1) and a sludge mixed solution storage tank (2) , nitrifying liquid water tank (3), sludge fermentation coupled short-range denitrification reactor (4), intermediate water tank (5), anammox biofilm reactor (6), effluent water tank (7); The sludge mixed liquor storage tank (2) is provided with a stirring device III (2.1); the sludge fermentation coupled short-range denitrification reactor (4) is provided with a built-in sludge feed pump (4.1), feed pump I (4.2), Drainage electric valve I (4.3), stirring device I (4.4), DO online detector I (4.5), first sampling port (4.6), second sampling port (4.7); the anammox biofilm reactor (6) Built-in inlet water pump II (6.1), intermediate water tank water pump (6.2), electric drain valve II (6.3), stirring device II (6.4), DO online detector II (6.5), packing and packing frame (6.6), The sampling port (6.7); the water outlet tank (7) is provided with an overflow pipe (7.1) and a drain pipe (7.2); Wherein, the sludge mixed liquid storage tank (2) is connected with the sludge fermentation coupled short-range denitrification reactor (4) through the sludge feed pump (4.1); The sludge fermentation is coupled with the short-range denitrification reactor (4); the sludge fermentation is coupled with the short-range denitrification reactor (4), and the drain electric valve I (4.3) is connected with the intermediate water tank (5); the intermediate water tank (5) passes through the intermediate water tank The water pump (6.2) is connected with the anammox biofilm reactor (6); the urban sewage raw water tank (1) is connected with the anammox biofilm reactor (6) through the feed pump II (6.1); The electric drain valve II (6.3) of the ammonia oxidation biofilm reactor (6) is connected with the water outlet tank (7). 2. the method for realizing sludge reduction and total nitrogen removal by applying the device according to claim 1, is characterized in that, comprises the following steps: 1) System startup: add hydrolysis acidification coupled short-range denitrification sludge to the sludge fermentation coupled short-range denitrification reactor (4), so that the sludge concentration in the reactor after inoculation reaches 2000-6000 mg/L; The biofilm packing of the anammox bacteria is added into the anammox biofilm reactor (6), so that the biofilm packing of the anammox bacteria occupies the effective volume of the anammox biofilm reactor (6). 20%～80%; 2) Determination of the amount of excess sludge, nitrification solution, raw water and intermediate nitrite solution: The remaining sludge was fermented at 30 degrees Celsius. By measuring the SCOD concentration, when the SCOD concentration did not increase and the SCOD value no longer increased within 20 minutes, it was the maximum potential of sludge fermentation at this concentration; In the sludge fermentation coupled short-range denitrification reactor (4), the organic matter and nitrate feeds are determined according to the calculation formulas (1) and (2):

V ₁ +V ₂ =V·P ₁ (2) Note: SCOD in the formula is the SCOD concentration under the maximum fermentation potential of the excess sludge; V ₁ , V ₂ , V are the organic matter feed, the nitrate solution feed and the effective volume of the reactor, respectively NO ₃ ^- is the influent nitrate concentration; C/N is the set value, and the value can be arbitrarily selected within the range of 3:1 to 6:1; P ₁ is the drainage ratio, the set value, which is 60%; In the anammox biofilm reactor (6), according to the calculation formula (3) (4), determine the raw water and intermediate water tank water inflow:

V ₃ +V ₄ =V·P ₂ (4) Note: in the formula NO ₂ ^- is the NO ₂ ^- concentration in the intermediate water tank, NH ₄ ^+- is the raw water NH ₄ ⁺ concentration; V ₃ , V ₄ , and V are the NO ₂ ^- solution feed, the NH ₄ ⁺ solution feed and the effective volume of the reactor, respectively; P ₂ is the drainage ratio, the set value, which is 50%; NO ₂ ^- /NH ₄ ⁺ is the set ratio, and the value can be arbitrarily selected within the range of 1.4:1 to 2:1; 3) The adjustment operation at runtime is as follows: Add the excess sludge to the sludge mixed liquid storage tank (1), start the agitator (1.1) before the start of each cycle to mix the excess sludge evenly, and then start the sludge feed pump (4.1), at the beginning of each cycle, the V ₁ volume of excess sludge mixed solution is pumped into the sludge fermentation coupled short-range denitrification reactor (4) to carry out sludge fermentation; When the sludge fermentation is coupled with the short-range denitrification reactor (4), anaerobic stirring is performed for 200-800 minutes in each cycle, and the anaerobic stirring is terminated when the SCOD value reaches more than 95% of the maximum fermentation potential; V2 volume of nitrification solution in the nitrification solution tank ( ₃ ) is pumped into the sludge fermentation coupled short-range denitrification reactor (4), so that the nitrate nitrogen concentration in the sludge fermentation coupled short-range denitrification reactor (4) is set to Concentration, set the concentration to meet the C/N ratio of 3:1 to 6:1; stir in anoxic until the nitrite conversion rate reaches more than 80% or the nitrate concentration is less than 3mg/L, then stop stirring and start precipitation and drainage for 10 minutes, idle Then enter the next cycle; After the sludge fermentation coupled with the short-range denitrification reactor (4) drains the water, the intermediate water tank water pump (6.2) is started to pump the nitrification solution of the intermediate water tank V ₃ volume into the anammox biofilm reactor (6), and at the same time the Pump II (6.1) pumps _V4 volume of raw urban sewage into the anaerobic ammonia oxidation biofilm reactor (6), so that the ratio of nitrite to ammonia nitrogen meets the set value, and the set value is 1.4:1～ Anything within the range of 2:1; anoxic stirring until the total inorganic nitrogen concentration is lower than 5mg/L, stop stirring, precipitate and drain for 10 minutes, and enter the next cycle after being idle.

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