A type based on A 2 Precise and zero-delay control method for biological nitrogen removal in wastewater treatment

Abstract

The present application relates to sewage treatment technical field, specifically to a kind of based on A 2 O sewage treatment biological denitrification precision zero delay control method.In municipal sewage A 2 O processing process, the total kjeldahl nitrogen concentration data of front end of anoxic and the nitrate nitrogen concentration data of anoxic end are acquired, and the total nitrogen concentration at the end of aerobic is predicted in time sequence;According to the real-time data of total kjeldahl nitrogen concentration at the front end of anoxic and the target concentration of kjeldahl nitrogen at the end of anoxic, the internal reflux ratio is real-time regulated;Direct monitoring or according to the influent flow of biological pool, external reflux flow, internal reflux flow and the concentration of nitrate nitrogen at the end of aerobic, the concentration of nitrate nitrogen at the front end of anoxic is calculated;On this basis, according to the concentration of nitrate nitrogen at the front end of anoxic and the set target concentration of nitrate nitrogen at the end of anoxic, the target denitrification amount is calculated in real time, and the dosing amount of additional carbon source is calculated in real time from the real-time target denitrification amount, to realize the real-time regulation of additional carbon source dosing.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method based on A 2 O is a precise and zero-delay control method for biological nitrogen removal in wastewater treatment. Background Technology

[0002] Currently, most municipal wastewater treatment plants use A. 2 The O process, or anaerobic-anoxic-aerobic biological nitrogen removal process, achieves biological nitrogen removal through nitrification and denitrification.

[0003] In biological nitrogen removal processes, to ensure that the total nitrogen in the effluent meets discharge standards, it is necessary to monitor and control process parameters at key points during operation. In traditional processes, the monitoring target is typically the total nitrogen in the wastewater effluent. Adjustments are made to parameters such as carbon source dosage and internal recirculation ratio based on the total nitrogen concentration. This control process suffers from significant lag. With process optimization, moving monitoring points upstream can address the severe lag problem of traditional monitoring methods. Examples include monitoring nitrate nitrogen at the anoxic and aerobic ends of the biological treatment tank, and monitoring ammonia and nitrate nitrogen at the anoxic end. However, in actual wastewater treatment plant operation, these methods only partially solve the problem of severe lag in traditional end-of-pipe monitoring and cannot achieve zero-delay, real-time, and accurate process monitoring and control.

[0004] Therefore, the method of this invention obtains the amount of nitrogen removal per unit of external carbon source under the current actual production conditions by using ammonia nitrogen concentration data at the front end of the anoxic process and nitrate nitrogen concentration data at the end of the anoxic process, and by combining time-series derivation calculations. This enables zero-delay real-time control of the internal reflux ratio and carbon source dosage during the operation of the biological denitrification process, fundamentally eliminating the lag in the previous process parameter control. This is of great significance for ensuring stable operation of the production process, stable effluent quality that meets discharge standards, and reducing reagent costs. Summary of the Invention

[0005] The purpose of this invention is to provide a method based on A 2 The O-type wastewater treatment biological denitrification precise zero-delay control method aims to solve the problems of unavoidable lag and inability to make real-time and accurate adjustments based on actual production conditions in existing process control schemes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method based on A 2 O-type wastewater treatment biological denitrification precise and zero-delay control method in municipal wastewater A 2In the O treatment process, total Kjeldahl nitrogen (TNK) concentration data at the anoxic front end, nitrate nitrogen concentration data at the anoxic front end, and nitrate nitrogen concentration data at the anoxic end are acquired. Based on the real-time TNK concentration data at the anoxic front end and the target TNK concentration data at the anoxic end, the internal recirculation ratio is adjusted in real time with zero delay. Based on the real-time adjustment of the internal recirculation ratio, the target nitrogen removal rate is calculated in real time according to the nitrate nitrogen concentration at the anoxic front end and the set target nitrate nitrogen concentration at the anoxic end. This real-time nitrogen removal rate is then used to calculate the amount of external carbon source added, achieving zero-delay real-time control of external carbon source addition and realizing precise biological nitrogen removal. Furthermore, the total Kjeldahl nitrogen concentration data at the anoxic front end and the nitrate nitrogen concentration data at the anoxic end are used to accurately predict the total nitrogen in the effluent over time.

[0007] Furthermore, at the current time T0, the real-time value of the total Kjeldahl nitrogen concentration at the hypoxic front end is TKN. (缺前，T0) The target value for total nitrogen concentration at the end of the anoxic phase is set as TN. 缺末目标 The target value for nitrate nitrogen concentration at the end of the anoxic section is NO3. - -N 缺末目标 The target value for the total Kjeldahl nitrogen concentration at the front end of the anoxic section is:

[0008]

[0009] because:

[0010]

[0011] Therefore, zero-delay real-time control of the internal reflux ratio can be achieved:

[0012]

[0013] In the formula, r is the internal reflux ratio; R is the external reflux ratio.

[0014] Furthermore, the aforementioned municipal sewage A 2 In the O treatment process, the nitrite nitrogen concentration in the biological system tends to be 0. If the organic nitrogen concentration at the anoxic front end is stable within the range of (0, 2.0 mg / L), the total organic nitrogen concentration at the anoxic front end can be set as a constant b mg / L based on the mode or mean of historical data. In this case, the total Kjeldahl nitrogen concentration can be calculated by monitoring the ammonia nitrogen concentration data at the anoxic front end. If the organic nitrogen concentration at the anoxic front end is unstable within the range of (0, 2.0 mg / L), the total Kjeldahl nitrogen concentration can be calculated by monitoring the total nitrogen concentration data and nitrate nitrogen concentration data at the anoxic front end.

[0015] Furthermore, based on the real-time control of the internal reflux ratio, in the wastewater treatment process, the influent flow rate, external reflux flow rate, internal reflux flow rate and the tank volume of each functional zone jointly determine the flow time of the sludge-water mixture in each functional zone. Let the flow time of the anoxic zone be T1, the flow time of the aerobic zone be T2, and the total Kjeldahl nitrogen concentration at the end of the aerobic zone be a mg / L.

[0016] Then we have:

[0017]

[0018] Therefore, the concentration of nitrate nitrogen at the aerobic terminal stage can be predicted from the time sequence:

[0019]

[0020] Therefore, the concentration of nitrate nitrogen at the anoxic end is calculated using the predicted aerobic end nitrate nitrogen concentration data, influent flow rate, external recirculation flow rate, and internal recirculation flow rate.

[0021]

[0022] Furthermore, if the total Kjeldahl nitrogen concentration at the aerobic end is stable within the range of (0, 2.0 mg / L), based on the mode or mean of historical data, 'a' can be set as a constant, and the concentration data of nitrate nitrogen at the anoxic end can be directly predicted; if the total Kjeldahl nitrogen concentration at the aerobic end is unstable within the range of (0, 2.0 mg / L), the nitrate nitrogen data at the aerobic end or the nitrate nitrogen data at the anoxic end can be directly monitored.

[0023] Furthermore, since the target nitrate nitrogen concentration at the end of the anoxic phase is NO3... - -N 缺末目标 If the influent flow rate is set to Q, then the real-time target nitrogen removal rate is § 目标 for:

[0024]

[0025] The amount of external carbon source added in real time can be calculated based on the target nitrogen removal rate in real time.

[0026] Furthermore, based on the fact that the mud-water mixture reaches the anoxic end after a time of T1 at the anoxic front end, during which denitrification occurs in the anoxic zone, the effective denitrification amount per unit of external carbon source can be calculated under the current actual production conditions based on historical data of nitrate nitrogen concentration at the anoxic front and anoxic end.

[0027] Furthermore, in actual production, the nitrogen removal rate § in the anoxic section is:

[0028]

[0029] When the carbon source dosage is X1:

[0030]

[0031] When the carbon source dosage is X2:

[0032]

[0033] The unit for nitrogen removal capacity § is kg / h;

[0034] Where X2-X1=△X, the change in the amount of nitrogen removal corresponding to the change in the amount of external carbon source added, △X, is:

[0035] Δ§=§2-§1;

[0036] Therefore, under the current actual production conditions, the external carbon source consumption coefficient PACC is:

[0037]

[0038] The physical meaning of PACC is: the amount of nitrogen removed per unit of external carbon source in actual production; the unit is: kg NO3. - -N / Kg carbon source; The physical meaning of carbon source addition amount X is: the mass of carbon source added per unit time, with the unit being Kg carbon source / h.

[0039] Furthermore, based on the current external carbon source consumption factor PACC, the nitrogen removal capacity §0 of the current raw water carbon source is calculated as follows:

[0040] §0 = §1 - ​​PACC * X1.

[0041] Furthermore, when it is necessary to remove § 目标 When the amount of nitrogen removed is §, the amount of nitrogen removed by the external carbon source 外加碳源 for:

[0042] § 外加碳源 =§ 目标 -§0;

[0043] Mass of external carbon source added per unit time X 外加碳源 for:

[0044]

[0045] Therefore, based on actual production conditions, and while making full use of the carbon source in the raw water, we can achieve accurate and real-time control of the amount of external carbon source added with zero delay.

[0046] The beneficial effects of this invention are:

[0047] 1. The method of this invention requires little equipment; when A 2 When the O process is running stably, only the ammonia nitrogen concentration data at the anoxic front end and the nitrate nitrogen concentration data at the anoxic end need to be obtained, resulting in lower equipment costs.

[0048] 2. The method of the present invention can achieve real-time control of the reflux ratio with zero delay, accurately control the concentration of total Kjeldahl nitrogen in the anoxic zone to ensure the load of the aerobic zone, and after adjustment, can perform real-time control of the carbon source dosage with zero delay to ensure the denitrification effect in the anoxic zone, thereby ensuring the stable compliance of the effluent. It achieves real-time adjustment without lag while ensuring the stable operation of the process.

[0049] 3. The method of this invention is closely aligned with actual production control. It utilizes advanced time-series algorithms to monitor the amount of nitrogen removed from raw water and the amount of nitrogen removed from external carbon sources in real time. This enables more accurate carbon source addition and control, achieving precise prediction of total nitrogen in the effluent and in-situ precise biological nitrogen removal. This is of great significance for ensuring effluent stability, saving reagents, and reducing costs. Detailed Implementation

[0050] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0051] In municipal sewage A 2 In the O treatment process, municipal wastewater undergoes an anaerobic-anoxic-aerobic process. In the aerobic section, ammonia nitrogen is oxidized to nitrate nitrogen through aerobic nitrification. The nitrate nitrogen is then returned to the anoxic section through internal recirculation, where it undergoes denitrification to achieve biological nitrogen removal.

[0052] During process operation, the internal and external recirculation has a dilution effect on the influent water quality indicators. In particular, the dilution of total Kjeldahl nitrogen in the influent can ensure the treatment load of the aerobic section. In addition, it may be necessary to add a carbon source in the anoxic section to ensure the denitrification reaction effect in the anoxic section.

[0053] In the following embodiments of the present invention, it should first be clarified that the total nitrogen in municipal wastewater treatment includes total nitrate nitrogen and total Kjeldahl nitrogen (TKN), wherein total nitrate nitrogen includes nitrate nitrogen and nitrite nitrogen, wherein the content of nitrite nitrogen is extremely low and can be ignored; total Kjeldahl nitrogen includes ammonia nitrogen and organic nitrogen, that is, total nitrogen = nitrate nitrogen + ammonia nitrogen + organic nitrogen, wherein nitrate nitrogen undergoes denitrification in the anoxic zone, ammonia nitrogen is oxidized to nitrate nitrogen in the aerobic zone, and organic nitrogen hardly changes in the anoxic and aerobic zones.

[0054] Secondly, in A 2 During the operation of the O process, the flow time of the sludge-water mixture in the anoxic zone is T1, and the flow time in the aerobic zone is T2. (It should be noted that the flow time of the sludge-water mixture in the anoxic and aerobic zones is determined by the influent flow rate, external return flow rate, internal return flow rate, and the tank volume of each functional zone, and changes in real time.) The influent volumetric flow rate of municipal sewage per unit time is Q, the internal return ratio is r, the external return ratio is R, and the tank volume is generally a fixed constant V. The current time is set as T0.

[0055] Example 1

[0056] In municipal sewage A 2 In actual operation of the O treatment process, it was found that the nitrite nitrogen concentration in the biological system tended to be 0 and could be ignored; the Kjeldahl nitrogen concentration at the aerobic end was stable in the range of (0, 2.0 mg / L); and the organic nitrogen concentration at the anoxic end was stable in the range of (0, 2.0 mg / L).

[0057] The relevant actual operating data for 2023 is as follows:

[0058] Table 1. Record of Kjeldahl nitrogen concentration in aerobic end-effluent.

[0059]

[0060]

[0061] Table 2. Record of Organic Nitrogen Concentration in Influent at the Anoxic Front End

[0062]

[0063]

[0064] It is clear that in municipal sewage A 2 During the stable operation of the O treatment process, the total Kjeldahl nitrogen concentration at the aerobic end can be set to a mg / L, and the total organic nitrogen concentration at the anoxic end can be set to b mg / L. a and b can be the mode or average of historical data.

[0065] Therefore, in this embodiment, an online ammonia nitrogen monitor is installed at the front end of the anoxic environment, and an online nitrate nitrogen monitor is installed at the end of the anoxic environment.

[0066] Therefore, the total nitrogen (TN) concentration at the hypoxia front end is:

[0067]

[0068] in:

[0069]

[0070] The total nitrogen (TN) concentration at the end of the anoxic phase is:

[0071]

[0072] The total nitrogen (TN) concentration at the aerobic end is:

[0073]

[0074] At the aerobic end:

[0075]

[0076] The aerobic terminal nitrate nitrogen concentration can be obtained from equations (2), (4), and (5), namely:

[0077]

[0078] In A 2 During the operation of the O process, the following are observed:

[0079]

[0080] The real-time nitrate nitrogen concentration at the anoxic front end can be obtained from equations (6) and (7). Based on the ammonia nitrogen concentration data detected at the anoxic front end and the nitrate nitrogen concentration data detected at the anoxic end, the concentration data of nitrate nitrogen at the anoxic front end can be calculated using an advanced time-series algorithm.

[0081] The target value for total nitrogen concentration at the end of the anoxic stage is set as TN. 缺末目标 At the end of the anoxic section, the target value for nitrate nitrogen concentration is NO3. - -N 缺末目标 The target value of total Kjeldahl nitrogen concentration at the front end of the anoxic section is denoted as TKN. 缺前目标 .

[0082] Therefore, in A 2 During the operation of the O process, at time T0, the internal reflux is controlled as follows:

[0083] Since the total Kjeldahl nitrogen remains almost unchanged during the anoxic phase, we have:

[0084]

[0085] Among them, TN 缺末目标 With NO3 - -N 缺末目标 All of these can be set to constant values ​​based on emission standards and actual production experience. Therefore, in this process, only the internal recirculation needs to be adjusted. With TKN 缺前目标 To maintain consistency, during the process, from equation (2), we obtain... From equation (8), we obtain TKN 缺前目标 ,Right now:

[0086]

[0087] That is:

[0088]

[0089] Therefore, in this embodiment, by measuring the ammonia nitrogen at the hypoxia front end, the internal reflux ratio can be adjusted with zero delay.

[0090] At time T0, the carbon source dosage is adjusted as follows:

[0091] Target total nitrogen removal § 目标 for:

[0092]

[0093] From equation (7), that is:

[0094]

[0095] Therefore, in the method of this invention, by measuring the concentration of ammonia nitrogen at the anoxic front end and the concentration of nitrate nitrogen at the anoxic end, and using an advanced time-series algorithm to calculate the total nitrogen concentration at the aerobic end at T1+T2, and after adjusting the internal reflux ratio, calculating the real-time concentration of nitrate nitrogen at the anoxic front end at T0, the target total nitrogen removal rate can be achieved. 目标 Real-time calculation.

[0096] Therefore, based on the real-time target total nitrogen removal amount § 目标 The amount of carbon source added is calculated.

[0097] In the technical solution of this invention, by analyzing historical production data, the amount of nitrogen removal from raw water carbon source and external carbon source is calculated, and the effective amount of nitrogen removal per unit of external carbon source is provided, thus providing the actual external carbon source consumption coefficient (PACC) in production, and completely solving the limitations of laboratory data.

[0098] First, the amount of nitrogen removed in the anoxic section is:

[0099]

[0100] Therefore, if the mass of carbon source added per unit time is X1, the amount of nitrogen removed §1 is:

[0101]

[0102] If the mass of carbon source added per unit time is X2, where X2-X1=△X, then the amount of nitrogen removed §2 is:

[0103]

[0104] Therefore, X2-X1=△X, and the change in nitrogen removal amount corresponding to the change in external carbon source △X is:

[0105] Δ§=§2-§1 (16)

[0106] Therefore, the external carbon source consumption coefficient (the amount of nitrogen removal per unit of carbon source) PACC in actual production is:

[0107] PACC=Δ§ / ΔX (17)

[0108] PACC unit is: Kg NO3 - -N / Kg carbon source.

[0109] The nitrogen removal capacity §0 from the raw water carbon source is:

[0110] §0=§1-PACC*X1 (18) Therefore, when it is necessary to remove § 目标 When the amount of nitrogen removed is §, the amount of nitrogen removed by the external carbon source 外加碳源 for:

[0111] § 外加碳源 =§ 目标 -§0 (19) From equations (17) and (19), we can obtain the mass X of the external carbon source added per unit time. 外加碳源 for:

[0112] X 外加碳源 =)§ 目标 -§0) / PACC (20)

[0113] Therefore, in this embodiment, by real-time detection and recording of ammonia nitrogen concentration at the anoxic front end, nitrate nitrogen concentration at the anoxic end, influent flow rate, internal recirculation flow rate, and external recirculation flow rate, combined with advanced time-series algorithms, the consumption coefficient of external carbon source in actual production and the amount of nitrogen removed from the raw water carbon source can be calculated. This enables zero-delay real-time calculation and adjustment of the internal recirculation ratio and the amount of external carbon source added, achieving accurate prediction of total nitrogen in the effluent and in-situ precise biological denitrification.

[0114] Table 3. Record of aerobic effluent concentration data in 2024 after using the method of this embodiment.

[0115]

[0116] As can be seen, the aerobic end-effect water can stably meet the standards using the method of this embodiment. In addition, the annual cumulative carbon source consumption was 109 ppm before the method of this embodiment was used. Under the condition that the influent water quality and quantity and the process did not change significantly, the annual cumulative carbon source consumption was 52 ppm after the method of this embodiment was used, and the carbon source addition consumption was reduced to 47.7%, saving 52.3% of the carbon source addition amount.

[0117] Example 2

[0118] If the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 2.0 mg / L) and is unstable, a certain degree of modification can be made to Example 1 based on Example 1. That is, in this example, an online ammonia nitrogen monitor and an online nitrate nitrogen monitor are installed at the anoxic end; and an online nitrate nitrogen monitor is installed at the anoxic end.

[0119] Similarly, formula (10) can be used to adjust the internal reflux ratio with zero delay; formula (20) can be used to calculate and add external carbon source dosage in real time with zero delay.

[0120] The difference between this embodiment and embodiment 1 is that the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 0.5 mg / L) and is unstable. Therefore, according to equations (6)-(7), it is not possible to accurately predict the nitrate nitrogen concentration at the aerobic end and the anoxic end. The nitrate nitrogen concentration at the anoxic end is directly monitored by the online nitrate nitrogen monitor at the anoxic end.

[0121] The total Kjeldahl nitrogen concentration at the anoxic front end can be obtained from the ammonia nitrogen data and the organic nitrogen data b obtained from the mode or mean of historical data, and the total nitrogen concentration in the aerobic effluent can be predicted by equation (4).

[0122] Example 3

[0123] If the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 2.0 mg / L) and is unstable, a certain degree of modification can be made to Example 1 based on Example 1. That is, in this example, an online ammonia nitrogen monitor is installed at the anoxic end, an online nitrate nitrogen monitor is installed at the anoxic end, and an online nitrate nitrogen monitor is installed at the aerobic end.

[0124] Similarly, formula (10) can be used to adjust the internal reflux ratio with zero delay; formula (20) can be used to calculate and add external carbon sources in real time.

[0125] The difference between this embodiment and embodiment 1 is that the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 2.0 mg / L) and is unstable. Therefore, according to equations (6)-(7), the nitrate nitrogen concentration at the aerobic end and the anoxic end cannot be accurately predicted. The calculation of the nitrate nitrogen concentration at the aerobic end is directly monitored by the online nitrate nitrogen monitor at the aerobic end, and then the nitrate nitrogen concentration at the anoxic end is calculated from the nitrate nitrogen concentration at the aerobic end.

[0126] The total Kjeldahl nitrogen concentration at the anoxic front end can be obtained from the ammonia nitrogen data and the organic nitrogen data b obtained from the mode or mean of historical data, and the total nitrogen concentration in the aerobic effluent can be predicted by equation (4).

[0127] Example 4

[0128] If the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 2.0 mg / L) and is unstable, and the organic nitrogen concentration at the anoxic end is not within the range of (0, 2.0 mg / L) and is unstable, then based on Example 1, a certain degree of modification can be made to Example 1. That is, in this example, an online total nitrogen monitor and an online nitrate nitrogen monitor are installed at the anoxic end, and an online nitrate nitrogen monitor is installed at the anoxic end.

[0129] Similarly, formula (10) can be used to adjust the internal reflux ratio with zero delay; formula (20) can be used to calculate and add external carbon sources in real time.

[0130] The difference between this embodiment and embodiment 1 is that if the Kjeldahl nitrogen concentration at the aerobic end is not within the range of (0, 2.0 mg / L) and is unstable, and the organic nitrogen concentration at the anoxic end is not within the range of (0, 2.0 mg / L) and is unstable, then the nitrate nitrogen concentration at the aerobic end and the anoxic end cannot be accurately predicted, nor can the total Kjeldahl nitrogen concentration at the anoxic end be accurately predicted. The calculation of the nitrate nitrogen concentration at the anoxic end is directly monitored by the online nitrate nitrogen monitor at the anoxic end. The total Kjeldahl nitrogen concentration can be obtained from the monitoring data of the total nitrogen concentration at the anoxic end and the monitoring data of the nitrate nitrogen concentration, and the total nitrogen concentration of the aerobic effluent can be predicted by equation (4).

[0131] This invention is not limited to the preferred embodiments described above. Anyone can derive other forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A method based on A 2 A precise, zero-delay control method for biological nitrogen removal in wastewater treatment, characterized by: In municipal sewage A 2 In the O treatment process, the total Kjeldahl nitrogen concentration data, the nitrate nitrogen concentration data at the anoxic front end, and the nitrate nitrogen concentration data at the anoxic end are obtained. Based on real-time data of total Kjeldahl nitrogen concentration at the anoxic front end and target total Kjeldahl nitrogen concentration at the anoxic end, the internal reflux ratio is adjusted in real-time with zero delay. Building upon this real-time adjustment, the target nitrogen removal rate is calculated in real-time based on the nitrate nitrogen concentration at the anoxic front end and the set target nitrate nitrogen concentration at the anoxic end. This target nitrogen removal rate is then used to calculate the external carbon source dosage in real-time, achieving zero-delay real-time control of external carbon source dosage and enabling precise biological nitrogen removal. Furthermore, the total Kjeldahl nitrogen concentration data at the anoxic front end and the nitrate nitrogen concentration data at the anoxic end are used to accurately predict the total nitrogen in the effluent over time. At the present moment At that time, the real-time value of the total Kjeldahl nitrogen concentration at the front end of the anoxic section was... ; The target value for total nitrogen concentration at the end of the anoxic section is set as follows: The target value for nitrate nitrogen concentration at the end of the anoxic section is The target value for the total Kjeldahl nitrogen concentration at the front end of the anoxic section is: because: ； Thus, zero-delay real-time control of the internal reflux ratio is achieved: ； In the formula, Internal reflux ratio; External reflux ratio; Based on real-time control of the internal recirculation ratio, in the wastewater treatment process, the influent flow rate, external recirculation flow rate, internal recirculation flow rate, and the volume of each functional zone jointly determine the circulation time of the sludge-water mixture in each functional zone. Let the circulation time in the anoxic zone be... The circulation time in the aerobic zone is The total Kjeldahl nitrogen concentration at the aerobic end was set as mg / L; Then we have: ； ； Therefore, the concentration of nitrate nitrogen at the aerobic terminal stage can be predicted based on time sequence: Therefore, the concentration of nitrate nitrogen at the anoxic end is calculated using the predicted aerobic end nitrate nitrogen concentration data, influent flow rate, external recirculation flow rate, and internal recirculation flow rate. ； Because the target nitrate nitrogen concentration at the end of the anoxic phase is Set the inlet flow rate to The real-time target nitrogen removal amount for: ； The amount of external carbon source added in real time is calculated based on the target nitrogen removal rate in real time.

2. A method based on A according to claim 1 2 A precise, zero-delay control method for biological nitrogen removal in wastewater treatment, characterized by: The municipal sewage A 2 In the O treatment process, the nitrite nitrogen concentration in the biological system tends to be 0; if the organic nitrogen concentration at the anoxic front end is stable within the range of (0, 2.0 mg / L), the total organic nitrogen concentration at the anoxic front end is set as a constant based on the mode or mean of historical data. If the concentration of organic nitrogen at the anoxic front is unstable within the range of (0, 2.0 mg / L), the concentration of total Kjeldahl nitrogen is calculated by monitoring the concentration of total nitrogen and nitrate nitrogen at the anoxic front.

3. A method based on A according to claim 1 2 A precise, zero-delay control method for biological nitrogen removal in wastewater treatment, characterized by: If the total Kjeldahl nitrogen concentration at the end of the aerobic process remains stable within the range of (0, 2.0 mg / L), then based on the mode or mean of historical data, Set as a constant, directly predict the nitrate nitrogen concentration data at the anoxic front end; if the total Kjeldahl nitrogen concentration at the aerobic end is unstable within the range of (0, 2.0 mg / L), directly monitor the nitrate nitrogen data at the anoxic front end or the nitrate nitrogen data at the aerobic end and then calculate the nitrate nitrogen data at the anoxic front end.

4. A method based on A according to claim 1 2 A precise, zero-delay control method for biological nitrogen removal in wastewater treatment, characterized by: Based on the process of mud-water mixture at the anoxic front end After a certain time, the anoxic end is reached, during which denitrification occurs in the anoxic zone. Based on historical data of nitrate nitrogen concentration at the anoxic front and anoxic end, the effective nitrogen removal rate per unit of external carbon source is calculated under the current actual production conditions.

5. A method based on A according to claim 4 2 The method for precise, zero-delay control of biological nitrogen removal in wastewater treatment is characterized by... In actual production, the amount of nitrogen removed in the anoxic section for: ； When the carbon source dosage is X1: ； When the carbon source dosage is X2: ； Denitrification The unit is kg / h; in Changes in the amount of external carbon source added The corresponding change in nitrogen removal amount for: ； Therefore, under current actual production conditions, the external carbon source consumption coefficient for: ； The physical meaning is: the amount of nitrogen removed per unit of external carbon source in actual production; the unit is: kg NO3. - -N / Kg carbon source; carbon source dosage The physical meaning of is: the mass of carbon source added per unit time, with the unit being Kg carbon source / h.

6. A method based on A according to claim 5 2 The method for precise, zero-delay control of biological nitrogen removal in wastewater treatment is characterized by... Based on the current external carbon source consumption coefficient Calculate the amount of nitrogen removed from the current raw water carbon source. for: 。 7. A method based on A according to claim 6 2 The method for precise, zero-delay control of biological nitrogen removal in wastewater treatment is characterized by... When removal is needed When the amount of nitrogen removed is [amount], the amount of nitrogen removed by the external carbon source is [amount]. for: ； Mass of external carbon source added per unit time for: ； Therefore, based on actual production conditions, and while making full use of the carbon source in the raw water, we can achieve accurate and real-time control of the amount of external carbon source added with zero delay.

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