Method and device for evaluating activated sludge denitrification performance

Abstract

The present invention discloses a method and device for evaluating the denitrification performance of activated sludge. The evaluation device comprises: a reactor; a spray device located above the interior of the reactor; a stirring device located below the interior of the reactor for stirring the sludge; an aeration unit with one end extending into the interior of the reactor and the other end connected to an air supply device; an ion detection unit for monitoring the concentration of various ions in the solution within the reactor; and a dissolved oxygen monitoring unit for monitoring the dissolved oxygen content within the reactor. This evaluation device can fully simulate the denitrification process and comprehensively evaluate the denitrification capacity of activated sludge.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and more particularly to a method and device for evaluating the denitrification performance of activated sludge. Background Art

[0002] The biological denitrification process is centered around activated sludge, with nitrification and denitrification as its foundation. The denitrification capacity of activated sludge is directly reflected in the magnitude of the nitrification / denitrification rate. The nitrification / denitrification rate is a key operating parameter that reflects the denitrification capacity. Using the measured nitrification / denitrification rate, the hydraulic retention time, dissolved oxygen, and other parameters of the biological reactor can be more reasonably determined, ensuring that the denitrification process is fully carried out without excessive retention time, thereby fully utilizing the structure. At the same time, the results of the denitrification performance evaluation can be used as an indicator for process evaluation and regulation, facilitating precise aeration and carbon source addition in water plant operations, thereby saving energy and reducing consumption. Furthermore, changes in the denitrification performance of activated sludge can more accurately expose hidden problems in operation and the risks associated with operational regulation.

[0003] Generally speaking, the evaluation of denitrification performance needs to consider the influence of many factors such as the water temperature of the biological reactor, the dissolved oxygen control level and inhibitors. The evaluation of the denitrification performance of activated sludge includes two parts: nitrification capacity and denitrification capacity. The traditional method does not clearly constrain the various parameters that affect the test results of nitrification / denitrification capacity. The results can only reflect the instantaneous working conditions and lack guidance for stage operation. Since there are no clear restrictions on the conditions that affect the test results, the results of multiple evaluations are not comparable, and it is impossible to explore the changes in sludge denitrification performance, nor to compare the differences in denitrification performance between different samples. In addition, the traditional evaluation method tests the two denitrification capacities of the active substances separately, which does not have the continuity of evaluation and the integrity of the process, increasing the risk of accidental errors in the results of different batches. The rate results are calculated through simple linear calculations, ignoring the stage changes of the denitrification process, and the results are not accurate enough.

[0004] Therefore, how to solve the shortcomings of traditional methods and improve the accuracy and guidance of the results is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for evaluating the denitrification performance of activated sludge, which can accurately evaluate the denitrification performance of activated sludge.

[0006] Based on the above objectives, the present invention provides an activated sludge denitrification performance evaluation device, comprising:

[0007] reactor;

[0008] A spraying device is provided above the interior of the reactor;

[0009] a stirring device, located at the lower part of the reactor, for stirring the sludge;

[0010] an aeration unit, one end of which extends into the interior of the reactor and the other end of which is connected to an air supply device;

[0011] The ion detection unit is used to monitor the concentration of various ions in the solution inside the reactor.

[0012] The dissolved oxygen monitoring unit is used to monitor the dissolved oxygen content inside the reactor.

[0013] In an optional solution, the reactor is made of transparent tempered glass with volume scales provided thereon.

[0014] In an optional solution, the stirring device has a stirring paddle, and the stirring paddle includes a first blade and a second blade that are symmetrically arranged, wherein the tail of the first blade is bent upward, and the tail of the second blade is bent downward.

[0015] In an optional solution, there are two stirring paddles, and the first blade and the second blade of the two stirring paddles are arranged opposite to each other.

[0016] In an optional solution, the top of the reactor is provided with an exhaust hole and a feed port; the bottom of the reactor is provided with a discharge port.

[0017] The present invention also provides a method for evaluating the denitrification performance of activated sludge, comprising the following steps:

[0018] Step 1: placing the centrifuged activated sludge in a reactor and washing the activated sludge;

[0019] Step 2: injecting ammonia nitrogen solution and COD solution of set concentration and volume into the reactor, controlling the ammonia nitrogen ion concentration and COD concentration in the mixed solution to be within a preset range; stirring the activated sludge, and recording the current ammonia nitrogen ion and nitrate nitrogen ion;

[0020] Step 3: introducing air into the reactor, monitoring the dissolved oxygen content inside the reactor, and controlling the dissolved oxygen content within a preset range;

[0021] Step 4: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of ammonia nitrogen ions between two consecutive times is less than the set value, stop aeration, and record the concentrations of ammonia nitrogen ions, nitrate nitrogen ions and COD at this time;

[0022] Step 5: nitrogen is introduced into the reactor to remove oxygen from the mixed liquid until the dissolved oxygen content is monitored to be lower than a set value;

[0023] Step 6: According to the nitrate ion concentration and COD concentration recorded at the end of step 4, determine the amount of COD solution and nitrate ion supplementation, control the COD concentration and nitrate ion concentration of the mixed solution within a preset range, and record the nitrate ion supplementation amount, ammonia nitrogen ion concentration, and nitrate nitrogen ion concentration;

[0024] Step 7: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of nitrate nitrogen ions between two adjacent measurements is less than the set value, and record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions at this time;

[0025] Step 8: Based on the data recorded in step 4, draw a curve of the change of ammonia nitrogen ion concentration and calculate the nitrification rate; based on the data recorded in step 7, draw a curve of the change of nitrate nitrogen ion concentration and calculate the denitrification rate.

[0026] In an optional solution, the nitrification rate is calculated according to the following formula:

[0027]

[0028] Where σ1 is the nitrification rate, and is the ammonia nitrogen ion concentration at the two end points of the linear change curve of ammonia nitrogen ion concentration, t i and t i+1 For and The corresponding two recording moments, n is the number of segments in which the ammonia nitrogen ion concentration curve changes linearly, and mlss is the sludge concentration in the mixed liquor.

[0029] In an optional solution, the denitrification rate is calculated according to the following formula:

[0030]

[0031] Where σ2 is the denitrification rate, and is the nitrate ion concentration at the two endpoints of the linear change curve of nitrate ion concentration, t j and t j+1 For and The corresponding two recorded moments, m is the number of linear change segments in the nitrate and nitrogen ion concentration change curve, and mlss is the sludge concentration in the mixed liquor.

[0032] In an optional solution, the method further comprises: calculating the total nitrogen removal efficiency during the entire process according to the following formula:

[0033]

[0034] Among them, σ3 is the removal efficiency of total nitrogen, and are the ammonia nitrogen ion concentration and nitrate nitrogen ion concentration recorded in step 2, The nitrate ion concentration added in step 6, and are the ammonia nitrogen ion concentration and nitric nitrogen ion concentration at the end of step 7, respectively; T is the duration of step 7 minus the duration of step 4; and mlss is the sludge concentration in the mixed liquor.

[0035] In an optional scheme, the cleaning of the activated sludge in step 1 includes: placing the sludge in the reactor, injecting a set amount of distilled water, recording the position of the scale line, stirring and dispersing, then letting it stand, removing the supernatant, and then injecting distilled water to the scale line; repeating 3 to 5 times to wash the sludge, and finally injecting distilled water to the scale line.

[0036] The beneficial effects of the present invention are:

[0037] The activated sludge denitrification performance evaluation method of the present invention fully simulates the denitrification process, evaluating nitrification, denitrification, and overall denitrification rate. This method evaluates the activated sludge's denitrification performance at each stage and overall, improving the integrity and comprehensiveness of the evaluation.

[0038] The initial evaluation conditions of the same batch of experiments are uniformly controlled, and the activated sludge becomes a single variable, eliminating the influence of external environmental differences, and more prominently evaluating the denitrification performance of the activated sludge itself, while also significantly improving the accuracy of the evaluation results. In addition, under unified standard conditions, the denitrification performance of samples at different times and spaces can be compared in the same batch of experiments, expanding the width and breadth of the use of the evaluation method.

[0039] The segmented calculation method is used to improve the accuracy of the results and provide a reference for water plants to achieve economical and low-carbon operation in denitrification.

[0040] The present invention has other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain certain principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

[0042] Figure 1 A schematic diagram showing the structure of an activated sludge denitrification performance evaluation device according to an embodiment of the present invention is shown.

[0043] Reference numerals:

[0044] 1. Air supply device, 2. Aeration head, 3. External stirring power device, 4. Stirring device, 5. DO concentration probe, 6. Dissolved oxygen monitoring unit, 7. Ion concentration probe, 8. Ion monitoring unit, 9. Reactor body, 10. Feed inlet, 11. Spray device, 12. Exhaust hole, 13. Upper head, 14. Lower head, 15. Discharge port. DETAILED DESCRIPTION

[0045] The present invention will be described in more detail below. Although the present invention provides preferred embodiments, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Instead, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0046] Example 1

[0047] refer to Figure 1 An embodiment of the present invention provides an activated sludge denitrification performance evaluation device, comprising:

[0048] reactor;

[0049] A spraying device is provided above the interior of the reactor;

[0050] a stirring device, located at the lower part of the reactor, for stirring the sludge;

[0051] an aeration unit, one end of which extends into the interior of the reactor and the other end of which is connected to an air supply device;

[0052] The ion monitoring unit is used to monitor the concentration of various ions in the solution inside the reactor.

[0053] The dissolved oxygen monitoring unit is used to monitor the dissolved oxygen content inside the reactor.

[0054] Specifically, in this embodiment, the reactor includes an upper head 13, a reactor body 9 and a lower head 14. The upper head 13 and the lower head 14 are both connected to the reactor body 9 through flanges.

[0055] The stirring device 4 is connected to the lower head 14 through an opening, a gasket is added at the connection to form a seal, and is connected to the external stirring power device 3. Furthermore, the stirring device 4 has two sets of upper and lower stirring paddles with parallel horizontal axes.

[0056] The stirring device 4 has a stirring paddle, which includes a first blade and a second blade symmetrically arranged, wherein the tail of the first blade is bent upward and the tail of the second blade is bent downward. In this embodiment, there are two stirring paddles, and the first blade and the second blade of the two stirring paddles are arranged opposite to each other.

[0057] Furthermore, the maximum height difference between the two sets of stirring paddles is 2-3 cm, the vertical distance between the centers is 3-5 cm, and the minimum distance between the blades is 1 cm.

[0058] The reactor body 9 is made of transparent tempered glass, is cylindrical, has a diameter of 15-20 cm, and a height of 20-30 cm, and has accurate volume scales on the reactor wall.

[0059] The spray device 11 is connected to the upper head through an opening and fixed by a rubber ring. The diameter of the spray device is 5-10 cm.

[0060] The upper head 13 is a spherical structure made of transparent tempered glass. It is connected to the reactor body 9 through a flange and is equipped with a sealing ring for sealing. There are an exhaust hole 12 and a feed port 10 on the upper part. Furthermore, the exhaust hole 12 has a diameter of 1 cm and can be sealed with a rubber plug; the feed port 10 is a circular hole with a diameter of 2-3 cm and can be sealed with a rubber plug.

[0061] The lower head 14 is a spherical structure made of transparent tempered glass. It is connected to the reactor body 9 via a flange and has a sealing ring inside for sealing. Furthermore, the lower head 14 is provided with two air holes connected to the aeration head 2; and a discharge port 15 with a diameter of 1-2 cm is used to empty the reactor after the evaluation process.

[0062] The aeration head 2 is located below the stirring device 4 and is connected to the lower head 14 through a rubber tube.

[0063] The gas supply device 1 is connected to the aeration head 2 in the reactor through a gas supply pipeline, and can continuously supply nitrogen and oxygen into the reactor.

[0064] The ion monitoring unit includes an ion concentration probe and a display unit. The ion concentration probe extends into the reactor, and the display unit is used to display the detected ion concentration. The ion monitoring unit 8 can monitor the concentration changes of ammonia nitrogen, nitrate nitrogen, and COD in the mixed solution through the ion concentration probe 7. Furthermore, the ion concentration probe 7 is connected to the reactor body 9 through an opening, and the connection is sealed with a rubber ring.

[0065] The dissolved oxygen monitoring unit 6 can monitor the dissolved oxygen changes in the mixed solution through the DO concentration probe 5. The DO concentration probe 7 is connected to the reactor body 9 through an opening, and the connection is sealed with a rubber ring.

[0066] The evaluation device can be used to fully simulate the denitrification process and fully evaluate the denitrification capacity of activated sludge.

[0067] Example 2

[0068] This embodiment provides a method for evaluating the denitrification performance of activated sludge, comprising the following steps:

[0069] Step 1: placing the centrifuged activated sludge in a reactor and washing the activated sludge;

[0070] Step 2: injecting ammonia nitrogen solution and COD solution of set concentration and volume into the reactor, controlling the ammonia nitrogen ion concentration and COD concentration in the mixed solution to be within a preset range; stirring the activated sludge, and recording the current ammonia nitrogen ion and nitrate nitrogen ion;

[0071] Step 3: introducing air into the reactor, monitoring the dissolved oxygen content inside the reactor, and controlling the dissolved oxygen content within a preset range;

[0072] Step 4: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of ammonia nitrogen ions between two consecutive times is less than the set value, stop aeration, and record the concentrations of ammonia nitrogen ions, nitrate nitrogen ions and COD at this time;

[0073] Step 5: nitrogen is introduced into the reactor to remove oxygen from the mixed liquid until the dissolved oxygen content is monitored to be lower than a set value;

[0074] Step 6: According to the nitrate ion concentration and COD concentration recorded at the end of step 4, determine the amount of COD solution and nitrate ion supplementation, control the COD concentration and nitrate ion concentration of the mixed solution within a preset range, and record the nitrate ion supplementation amount, ammonia nitrogen ion concentration, and nitrate nitrogen ion concentration;

[0075] Step 7: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of nitrate nitrogen ions between two adjacent measurements is less than the set value, and record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions at this time;

[0076] Step 8: Based on the data recorded in step 4, draw a curve of the change of ammonia nitrogen ion concentration and calculate the nitrification rate; based on the data recorded in step 7, draw a curve of the change of nitrate nitrogen ion concentration and calculate the denitrification rate.

[0077] The following describes this method with a specific example:

[0078] Step 1) 50-150 g of centrifuged activated sludge is placed in a reactor, and 1.5-2 L of distilled water is injected, the position of the scale line is recorded, and the mixture is stirred and dispersed, and then allowed to stand. The supernatant liquid is removed by siphoning through the feed port with a hose, and then distilled water is injected to the scale line; this is repeated 3-5 times to wash the sludge, and finally distilled water is injected to the scale line.

[0079] Step 2) Inject concentrated solutions of ammonia nitrogen and COD into the reaction device according to the calculated ratio, and control the concentration of the mixed solution to reach 15-20 mg / L ammonia nitrogen concentration and 30-40 mg / L COD concentration; the initial conditions of the same batch of experiments are fixed, and the conditions of each batch can be adjusted according to the operation of the activated sludge source plant; record the current concentrations of ammonia nitrogen and nitrate nitrogen respectively and

[0080] Step 3) Air is then introduced into the system to control the DO value in the mixed solution to 2-3 mg / L;

[0081] Step 4) Continuously record the concentrations of ammonia nitrogen and nitrate nitrogen in the mixed solution at different times until the change in ammonia nitrogen ion concentration between two consecutive measurements is below 0.1 mg / L. Aeration is then stopped and the ammonia nitrogen, nitrate nitrogen, and COD values ​​are recorded. Step 5) Continuously pump nitrogen into the reactor to remove oxygen from the mixed solution, control the DO value of the mixed solution to 0, and stop the gas supply.

[0082] Step 6) According to the nitrate ion concentration and COD concentration recorded at the end of step 4, the amount of COD solution and nitrate ion supplement is determined, and the COD value and nitrate nitrogen value of the mixed solution are controlled to be 35-45 mg / L and 15-20 mg / L, respectively. Furthermore, the initial conditions of the same batch experiment are fixed, and the conditions of each batch can be adjusted according to the operation of the activated sludge source plant; record the nitrate nitrogen supplement amount Ammonia nitrogen, nitrate nitrogen and COD values.

[0083] Step 7) Continuously record the concentrations of ammonia nitrogen and nitrate nitrogen in the mixed solution at different times until the change in the concentration of nitrate nitrogen ions between two adjacent times is below 0.1 mg / L, stop aeration, and record the concentrations of ammonia nitrogen and nitrate nitrogen at the end. and

[0084] Step 8) Based on the data recorded in step 4, a curve of the change in ammonia nitrogen ion concentration is drawn, and the nitrification rate is calculated according to the following formula:

[0085]

[0086] Where σ1 is the nitrification rate, and is the ammonia nitrogen ion concentration at the two end points of the linear change curve of ammonia nitrogen ion concentration, t i and t i+1 For and The corresponding two recording moments, n is the number of segments in which the ammonia nitrogen ion concentration curve changes linearly, and mlss is the sludge concentration in the mixed liquor.

[0087] According to the data recorded in step 7, a curve of the change of nitrate and nitrogen ion concentration is drawn, and the denitrification rate is calculated according to the following formula:

[0088]

[0089] Where σ2 is the denitrification rate, and is the nitrate ion concentration at the two endpoints of the linear change curve of nitrate ion concentration, t j and t j+1 For and The corresponding two recorded moments, m is the number of linear change segments in the nitrate and nitrogen ion concentration change curve, and mlss is the sludge concentration in the mixed liquor.

[0090] The method further comprises calculating the total nitrogen removal efficiency during the entire process according to the following formula:

[0091] The total nitrogen removal efficiency of the entire process was calculated according to the following formula:

[0092]

[0093] Among them, σ3 is the removal efficiency of total nitrogen, and are the ammonia nitrogen ion concentration and nitrate nitrogen ion concentration recorded in step 2, The nitrate ion concentration added in step 6, and are the ammonia nitrogen ion concentration and nitric nitrogen ion concentration at the end of step 7, respectively; T is the duration of step 7 minus the duration of step 4; and mlss is the sludge concentration in the mixed liquor.

[0094] In the device described herein, the aeration head is installed below the stirring device, increasing the mass transfer efficiency of the aerated gas in the mixed liquid, improving the formation and conversion efficiency of aerobic and anaerobic environments. This device also offers advantages such as a high degree of automation and real-time monitoring of ion changes, significantly saving manpower and testing costs.

[0095] This method uses automated equipment to conduct a complete denitrification process evaluation, starting with the nitrification capacity evaluation process and ending with the denitrification capacity evaluation process. The initial evaluation conditions of each stage of the same batch of experiments are strictly controlled, and the denitrification capacity is expressed by the reduction of nitrate nitrogen and ammonia nitrogen under fixed conditions. This method fully simulates all stages of denitrification, and the process is more complete. At the same time, this method uses strictly controlled standardized conditions to eliminate the interference of external environmental differences on the results, which not only improves the accuracy of the results but also enables the comparison of evaluation results of activated sludge from different sources and homologous sludge at different time points in the same batch evaluation, thereby enhancing the exploration of the changing laws of activated sludge denitrification performance. In addition, the calculation of the evaluation results of each stage adopts a segmented calculation method, which makes the calculation results more accurate.

[0096] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for evaluating the denitrification performance of activated sludge, based on an activated sludge denitrification performance evaluation device, the device comprising: reactor; A spraying device is provided above the interior of the reactor; a stirring device, located at the lower part of the reactor, for stirring the sludge; an aeration unit, one end of which extends into the interior of the reactor and the other end of which is connected to an air supply device; An ion detection unit, used to monitor the concentration of various ions in the solution inside the reactor; A dissolved oxygen monitoring unit, used to monitor the dissolved oxygen content inside the reactor; Characterized in that the method comprises the following steps: Step 1: placing the centrifuged activated sludge in a reactor and washing the activated sludge; Step 2: injecting ammonia nitrogen solution and COD solution of set concentration and volume into the reactor, controlling the ammonia nitrogen ion concentration and COD concentration in the mixed solution to be within a preset range; stirring the activated sludge, and recording the current concentrations of ammonia nitrogen ions and nitrate nitrogen ions; Step 3: introducing air into the reactor, monitoring the dissolved oxygen content inside the reactor, and controlling the dissolved oxygen content within a preset range; Step 4: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of ammonia nitrogen ions between two consecutive times is less than the set value, stop aeration, and record the concentrations of ammonia nitrogen ions, nitrate nitrogen ions and COD at this time; Step 5: nitrogen is introduced into the reactor to remove oxygen from the mixed liquid until the dissolved oxygen content is monitored to be lower than a set value; Step 6: According to the nitrate ion concentration and COD concentration recorded at the end of step 4, determine the amount of COD solution and nitrate ion supplementation, control the COD concentration and nitrate ion concentration of the mixed solution within a preset range, and record the nitrate ion supplementation amount, ammonia nitrogen ion concentration, and nitrate nitrogen ion concentration; Step 7: Continuously record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions in the mixed solution at set time intervals until the change in the concentration of nitrate nitrogen ions between two adjacent measurements is less than the set value, and record the concentrations of ammonia nitrogen ions and nitrate nitrogen ions at this time; Step 8: Based on the data recorded in step 4, draw a curve of the change of ammonia nitrogen ion concentration and calculate the nitrification rate; based on the data recorded in step 7, draw a curve of the change of nitrate nitrogen ion concentration and calculate the denitrification rate.

2. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The reactor is made of transparent tempered glass and is provided with volume scales.

3. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The stirring device has a stirring paddle, and the stirring paddle includes a first blade and a second blade that are symmetrically arranged, wherein the tail of the first blade is bent upward, and the tail of the second blade is bent downward.

4. The activated sludge denitrification performance evaluation method according to claim 3, characterized in that: There are two stirring paddles, and the first blade and the second blade of the two stirring paddles are arranged opposite to each other.

5. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The top of the reactor is provided with an exhaust hole and a feed port; the bottom of the reactor is provided with a discharge port.

6. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The nitrification rate was calculated according to the following formula: ； Where σ1 is the nitrification rate, N NH4+i and N NH4+i+1 is the ammonia nitrogen ion concentration at the two end points of the linear change curve of ammonia nitrogen ion concentration, t i and t i+1 For N NH4+i and N NH4+（i+1） The corresponding two recording moments, n is the number of segments in which the ammonia nitrogen ion concentration curve changes linearly, and mlss is the sludge concentration in the mixed liquor.

7. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The denitrification rate was calculated according to the following formula: ； Where σ2 is the denitrification rate, and is the nitrate ion concentration at the two endpoints of the linear change curve of nitrate ion concentration, t j and t j+1 For and The corresponding two recorded moments, m is the number of linear change segments in the nitrate and nitrogen ion concentration change curve, and mlss is the sludge concentration in the mixed liquor.

8. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The method further comprises: calculating the total nitrogen removal efficiency during the entire process according to the following formula: σ3=((N NH4+0 +N NO3-0 +N NO3-b )-(N NH4+F + N NO3-F )) / T×mlss Among them, σ3 is the removal efficiency of total nitrogen, N NH4+0 and N NO3-0 are the ammonia nitrogen ion concentration and nitrate nitrogen ion concentration recorded in step 2, N NO3-b The concentration of nitrate ions added in step 6, N NH4+F , N NO3-F is the ammonia nitrogen ion concentration and the nitric nitrogen ion concentration at the end of step 7, and T is the duration of step 7 minus the duration of step 4.

9. The activated sludge denitrification performance evaluation method according to claim 1, characterized in that: The cleaning of the activated sludge in step 1 includes: placing the sludge in the reactor, injecting a set amount of distilled water, recording the position of the scale line, stirring and dispersing, then standing, removing the supernatant, and then injecting distilled water to the scale line; repeating 3 to 5 times to wash the sludge, and finally injecting distilled water to the scale line.

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