Sewage treatment method, device, equipment and medium based on air supply control

Abstract

The present application relates to sewage treatment technical field, disclose a sewage treatment method, device, equipment and medium based on air supply control, the sewage treatment method based on air supply control includes: obtain the ammonia nitrogen removal amount design value of membrane aeration biofilm reactor, according to ammonia nitrogen removal amount design value and oxygen loss related parameters, determine the reference air supply amount;Based on the preset nonlinear function, according to the reference air supply amount, real-time influent ammonia nitrogen concentration and influent ammonia nitrogen design value, determine real-time feedforward air supply amount;According to the real-time tail gas oxygen content deviation and reference air supply amount, determine real-time air supply correction amount;Through real-time feedforward air supply amount, real-time air supply correction amount and preset air supply threshold, the target real-time air supply amount of membrane aeration biofilm reactor is controlled to carry out sewage treatment, the present application determines the target real-time air supply amount by adjusting real-time feedforward air supply amount and real-time air supply correction amount in real time, improves the accuracy of target real-time air supply amount.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and particularly relates to a sewage treatment method and device based on air supply control, equipment and medium. BACKGROUND

[0002] Sewage is produced in human production, life and other activities, and is water body that loses original use value or is polluted. Sewage has complex components and contains various pollutants, and thus cannot be directly reused or discharged into the natural environment. Therefore, sewage needs to be treated.

[0003] In related technologies, sewage is treated by an aerobic tank. The aerobic tank is a core unit of a sewage treatment system that uses aerobic microorganisms to degrade pollutants. The aerobic tank continuously introduces air into the tank through an aeration system, so that the dissolved oxygen concentration in the sewage meets the respiratory needs of aerobic microorganisms, so as to convert organic pollutants, ammonia nitrogen and the like in the sewage into harmless substances through the metabolic action of microorganisms.

[0004] However, the method of treating sewage by the aerobic tank relies on the diffusion of oxygen dissolved in the liquid phase by air bubbles. Oxygen needs to overcome the resistance of the gas-liquid interface to be transmitted to microorganisms. Therefore, the application of a membrane aeration biofilm reactor is gradually widespread. The membrane aeration biofilm reactor transmits oxygen to the biofilm attached to the membrane surface through a gas-permeable membrane. Microorganisms in the biofilm directly use oxygen for reaction. Meanwhile, wastewater flows on the other side of the membrane. Pollutants enter the biofilm by diffusion and are degraded.

[0005] However, the air supply amount of the current membrane aeration biofilm reactor is often determined by an empirical method or an experimental optimization method, which results in inaccurate air supply amount and poor sewage treatment effect. SUMMARY

[0006] Therefore, the present application provides a sewage treatment method and device based on air supply control, equipment and medium to solve the problem of inaccurate air supply amount of the current membrane aeration biofilm reactor.

[0007] In a first aspect, the present application provides a wastewater treatment method based on air supply control, comprising: obtaining an ammonia nitrogen removal amount design value of a membrane aerated biofilm reactor; determining a reference air supply amount of the membrane aerated biofilm reactor according to the ammonia nitrogen removal amount design value and an oxygen loss related parameter; the oxygen loss related parameter is a parameter related to the loss of oxygen from the gas source to the process of being utilized by microorganisms; adjusting the reference air supply amount based on a preset nonlinear function according to a real-time influent ammonia nitrogen concentration and an influent ammonia nitrogen design value of the membrane aerated biofilm reactor to obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor; determining a real-time air supply correction amount according to a real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor; and cooperatively controlling a target real-time air supply amount of the membrane aerated biofilm reactor to perform wastewater treatment through the real-time feedforward air supply amount, the real-time air supply correction amount, and a preset air supply amount threshold.

[0008] The present application obtains an ammonia nitrogen removal amount design value of a membrane aerated biofilm reactor, determines a reference air supply amount of the membrane aerated biofilm reactor according to the ammonia nitrogen removal amount design value and an oxygen loss related parameter, considers the oxygen transfer loss in the aeration process, so that the reference air supply amount is more in line with the actual situation and is more accurate. The present application adjusts the reference air supply amount based on a preset nonlinear function according to a real-time influent ammonia nitrogen concentration and an influent ammonia nitrogen design value of the membrane aerated biofilm reactor to obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor. The present application introduces a preset nonlinear function to process the ammonia nitrogen load fluctuation intensity through real-time monitoring of the influent ammonia nitrogen concentration, avoids overcompensation in the high concentration interval, adjusts the air supply amount in time when the influent ammonia nitrogen concentration suddenly changes, obtains the real-time feedforward air supply amount, overcomes the hysteresis problem of single feedback control, and improves the response speed of MABR air supply amount adjustment. The present application determines a real-time air supply correction amount according to a real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor. The present application obtains the real-time real-time air supply correction amount through real-time monitoring of the tail gas oxygen content deviation, and improves the accuracy of the real-time air supply correction amount. The present application dynamically corrects the air supply amount through the tail gas oxygen content deviation, eliminates model errors and external disturbances. The present application cooperatively controls a target real-time air supply amount of the membrane aerated biofilm reactor to perform wastewater treatment through the real-time feedforward air supply amount, the real-time air supply correction amount, and a preset air supply amount threshold. The preset air supply amount threshold is used to limit the air supply amount range to avoid waste or insufficient air supply caused by continuous errors. According to the cooperative control of the real-time feedforward air supply amount and the real-time air supply correction amount, disturbances such as membrane fouling and biofilm thickness changes are effectively inhibited, air supply redundancy during low load periods of influent ammonia nitrogen is avoided, air supply is insufficient during high load periods, energy consumption waste caused by air supply is reduced, the accuracy of the target real-time air supply amount is improved, the stability of wastewater treatment is improved, and the effect of wastewater treatment is optimized.

[0009] In an alternative embodiment, the ammonia nitrogen removal amount design value of the membrane aerated biofilm reactor is obtained, comprising: obtaining an ammonia nitrogen deviation design value according to the difference between the influent ammonia nitrogen design value and the effluent ammonia nitrogen design value of the membrane aerated biofilm reactor; obtaining the ammonia nitrogen removal amount design value according to the product of the ammonia nitrogen deviation design value, the preset treatment water amount and the unit conversion coefficient; and the ammonia nitrogen removal amount design value is a preset ammonia nitrogen removal amount of the membrane aerated biofilm reactor.

[0010] In an alternative embodiment, the oxygen loss related parameters include biofilm oxygen utilization rate, oxygen transfer efficiency, air density, mass fraction of oxygen in air and theoretical oxygen demand per unit ammonia nitrogen removal amount; the reference air supply amount of the membrane aerated biofilm reactor is determined according to the ammonia nitrogen removal amount design value and the oxygen loss related parameters, comprising: obtaining a theoretical oxygen demand according to the product of the theoretical oxygen demand per unit ammonia nitrogen removal amount and the ammonia nitrogen removal amount design value; determining an oxygen effective supply coefficient according to the product of the biofilm oxygen utilization rate, the oxygen transfer efficiency, the air density and the mass fraction of oxygen in air; and determining the reference air supply amount according to the quotient of the theoretical oxygen demand and the oxygen effective supply coefficient.

[0011] In an alternative embodiment, the real-time feedforward air supply amount of the membrane aerated biofilm reactor is obtained by adjusting the reference air supply amount based on a preset nonlinear function according to the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value of the membrane aerated biofilm reactor, comprising: obtaining an ammonia nitrogen load fluctuation intensity according to the quotient of the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value; nonlinearly correcting the ammonia nitrogen load fluctuation intensity by using the preset nonlinear function to obtain a nonlinear correction term of ammonia nitrogen fluctuation; obtaining a first summation result according to the sum of a preset value and the nonlinear correction term; and obtaining the real-time feedforward air supply amount of the membrane aerated biofilm reactor according to the product of the reference air supply amount and the first summation result.

[0012] In an alternative embodiment, the real-time air supply correction amount is determined according to the real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor, comprising: determining a proportional term and an integral term according to the real-time tail gas oxygen content deviation; obtaining a second summation result according to the sum of the proportional term and the integral term; and obtaining the real-time air supply correction amount according to the product of the second summation result and the reference air supply amount.

[0013] In an alternative embodiment, the target real-time air supply amount of the membrane aerated biofilm reactor is cooperatively controlled to perform wastewater treatment by using the real-time feedforward air supply amount, the real-time air supply correction amount and a preset air supply amount threshold, comprising: cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor to perform wastewater treatment according to the sum of the real-time feedforward air supply amount and the real-time air supply correction amount, with the preset air supply amount threshold as a constraint.

[0014] In a second aspect, the present application provides a wastewater treatment device based on air supply control, comprising: a reference determination module, configured to obtain an ammonia nitrogen removal amount design value of a membrane aerated biofilm reactor, and determine a reference air supply amount of the membrane aerated biofilm reactor according to the ammonia nitrogen removal amount design value and an oxygen loss related parameter; the oxygen loss related parameter is a parameter related to the loss of oxygen from the gas source to the process of being utilized by microorganisms; a feedforward control module, configured to adjust the reference air supply amount based on a preset nonlinear function, according to a real-time influent ammonia nitrogen concentration and an influent ammonia nitrogen design value of the membrane aerated biofilm reactor, to obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor; a feedback control module, configured to determine a real-time air supply correction amount according to a real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor; and an air supply amount synthesis module, configured to cooperatively control a target real-time air supply amount of the membrane aerated biofilm reactor by the real-time feedforward air supply amount, the real-time air supply correction amount, and a preset air supply amount threshold, to perform wastewater treatment.

[0015] In a third aspect, the present application provides a computer device, comprising: a memory and a processor, which are in communication connection with each other, and the memory stores computer instructions; the processor executes the computer instructions to perform the wastewater treatment method based on air supply control of the first aspect or any of the corresponding embodiments thereof.

[0016] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions for causing a computer to perform the wastewater treatment method based on air supply control of the first aspect or any of the corresponding embodiments thereof.

[0017] In a fifth aspect, the present application provides a computer program product, comprising computer instructions for causing a computer to perform the wastewater treatment method based on air supply control of the first aspect or any of the corresponding embodiments thereof. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the specific embodiments or the related art, the drawings needed in the specific embodiments or the related art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 is a flowchart of a wastewater treatment method based on air supply control according to an embodiment of the present application.

[0020] Figure 2 is a flowchart of another wastewater treatment method based on air supply control according to an embodiment of the present application.

[0021] Figure 3 is a structural block diagram of a sewage treatment device based on air supply amount control according to an embodiment of the present application.

[0022] Figure 4 is a hardware structure schematic diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0024] In the related art, the aeration mode of the aerobic tank is usually to inject air or oxygen into water through a diffuser or an aeration head to form bubbles, and oxygen is dissolved into water through the gas-liquid interface for the aerobic metabolism of microorganisms. The MABR (Membrane Aerated Biofilm Reactor) is to transmit oxygen to the biofilm attached to the membrane surface through the gas-permeable membrane, and the microorganisms in the biofilm directly use oxygen for reaction, while the wastewater flows on the other side of the membrane, and the pollutants are degraded by diffusing into the biofilm.

[0025] For the aeration mode of the aerobic tank, the transmission direction of oxygen is from the gas phase to the liquid phase to the microorganisms, which belongs to one-way diffusion, the mass transfer interface is the gas-liquid interface (bubble and water body contact), and the diffusion driving force is the concentration gradient (difference between dissolved oxygen in water and microbial demand). For the aeration mode of the MABR, the transmission direction of oxygen is from the gas phase in the membrane to the biofilm to the liquid phase, which belongs to countercurrent diffusion, the mass transfer interface is the gas-biofilm interface (oxygen directly penetrates the membrane), and the diffusion driving force is the oxygen partial pressure difference (pressure gradient inside and outside the membrane). For the aeration mode of the aerobic tank, the oxygen needs to overcome the gas-liquid interface resistance (such as liquid film resistance) to be transmitted to the microorganisms. In the aeration mode of the MABR, oxygen directly enters the biofilm in the form of molecular diffusion through the hydrophobic membrane material (such as polytetrafluoroethylene), and forms a countercurrent transmission (oxygen to the outside of the membrane, and pollutants to the inside of the membrane) with the pollutants in the sewage, which significantly improves the mass transfer efficiency (the mass transfer coefficient is increased by 3-5 times).

[0026] For the aeration mode of the aerobic tank, the microbial morphology is suspended floc (free floating), the oxygen distribution is the dissolved oxygen gradient stratification in the water body (high at the surface and low at the deep), and the functional partition is single aerobic environment. For the aeration mode of MABR, the microbial morphology is immobilized biofilm (attached to the membrane surface), the oxygen distribution is the oxygen gradient stratification in the biofilm (high at the membrane side and low at the outside), and the functional partition is from the aerobic layer (near the membrane side) to the anoxic layer (far from the membrane side).

[0027] For the aeration mode of the aerobic tank, the oxygen transfer obeys the double membrane theory, and for the aeration mode of MABR, the oxygen transfer through the membrane material obeys Fick's law. Because there is no bubble breaking energy loss, the oxygen transfer efficiency of the aeration mode of MABR is 50-100% higher than that of the aeration mode of the aerobic tank. Moreover, the immobilized microorganisms in the biofilm of the aeration mode of MABR have the following characteristics: substrate storage capacity, excess ammonia nitrogen can be temporarily adsorbed by extracellular polymers; colony stability, spatial stratification of bacterial colonies in the biofilm, resistance to population elution; oxygen buffer capacity, the dissolved oxygen in the membrane can maintain an emergency supply for 30-60 seconds.

[0028] For the aeration mode of MABR, the oxygen transfer mode is to supply oxygen directly to the biofilm through a gas permeable membrane (such as a hollow fiber membrane), and the oxygen diffuses to the inside of the biofilm through a concentration gradient at the membrane surface. The functional partition of the biofilm is that the outer layer of the biofilm (near the sewage side) forms an anoxic / anaerobic zone (denitrification), and the inner layer (near the membrane side) forms an aerobic zone (nitrification). Simultaneous nitrification and denitrification: ammonia oxidation and total nitrogen removal can be completed simultaneously in a single reactor, which is especially suitable for wastewater treatment scenarios with high ammonia nitrogen and low carbon-nitrogen ratio. In the wastewater treatment process, MABR is usually applied in the anoxic unit. Through high oxygen transfer efficiency and oxygen utilization rate, ammonia nitrogen removal is achieved, and then denitrification is achieved in the anoxic unit, reducing the aeration amount and residence time of the downstream aerobic zone, thereby greatly saving energy. MABR has great advantages in upgrading and efficiency improvement, capacity expansion and standard upgrading of wastewater treatment plants.

[0029] However, unlike the extensive aeration mode of the aerobic tank, such as perforated pipe and aerator, due to the special bubbleless aeration mode of MABR, the MABR system control often uses empirical methods or is optimized through experiments, and is mostly limited to specific reaction systems, which is difficult to provide universal reference, limiting the popularization and application of MABR in actual wastewater treatment. Small gas supply cannot fully utilize the high oxygen transfer effect and simultaneous nitrification and denitrification performance of MABR. Large gas supply may lead to the dissolved oxygen concentration on the surface of the aeration membrane exceeding the tolerance range of microorganisms, thereby inhibiting the initial attachment of nitrifying bacteria on the surface of the aeration membrane, affecting the biofilm formation. On the other hand, it is easy to make oxygen penetrate the biofilm, resulting in high dissolved oxygen concentration on the surface of the membrane. High dissolved oxygen concentration may cause oxygen toxicity, affecting denitrification effect, and easily leading to biofilm detachment on the surface of the MABR membrane.

[0030] Aerobic tank aeration relies on a single feedback mechanism, such as dissolved oxygen control. This involves real-time monitoring of dissolved oxygen in the aerobic tank and comparing it with the system's set dissolved oxygen. The PID (Proportional-Integral-Derivative) algorithm calculates the deviation between the actual dissolved oxygen and the set dissolved oxygen, and then adjusts the blower valve / opening to adjust the aeration rate. This approach suffers from significant hysteresis, as changes in dissolved oxygen in the aerobic tank require sufficient mixing of the wastewater (a lag of 2-4 hours), and is typically unable to respond promptly to sudden changes in the influent load. It also wastes energy, maintaining high aeration rates even at low loads, and resulting in oxygen mass transfer efficiency of only 20%-30%.

[0031] Another traditional aeration control method involves feedforward control of the influent ammonia nitrogen concentration. This method monitors the influent ammonia nitrogen concentration in real time and adjusts the air supply based on the amount of oxygen required for nitrification per unit ammonia nitrogen concentration. This method suffers from large linear model errors. Limited by issues such as low oxygen mass transfer efficiency, the ammonia nitrogen concentration and the amount of oxygen available are not necessarily linearly related. High ammonia nitrogen concentrations can easily lead to overcompensation of the air supply, causing a sudden drop in oxygen mass transfer efficiency. Furthermore, this method does not incorporate changes in the system's microbial state. When the sludge concentration is too high or performance is poor, the actual oxygen demand may need to increase, but this control method cannot detect this in a timely manner.

[0032] An embodiment of the present invention provides a wastewater treatment method based on air supply control. By adjusting the real-time feedforward air supply and the real-time air supply correction in real time, the target air supply is determined, thereby improving the accuracy of the target air supply. Compared with traditional MABR air supply methods, this embodiment of the present invention can rapidly respond and precisely adjust the MABR air supply, improving the MABR's oxygen transfer efficiency (OTE) by 30%-40% and reducing overall energy consumption by over 20%-35%, fully leveraging the MABR's advantages of high oxygen transfer efficiency and high nitrification efficiency. Furthermore, this embodiment of the present invention does not rely on complex mechanistic models and can adapt to different water quality fluctuation scenarios, demonstrating strong universality.

[0033] According to an embodiment of the present invention, an embodiment of a sewage treatment method based on air supply volume control is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0034] In this embodiment, a sewage treatment method based on air supply control is provided, which can be used in a computer device, and can be a computer device for controlling a membrane aeration biofilm reactor. Figure 1is a flow chart of a sewage treatment method based on air supply amount control according to an embodiment of the present application, as shown in Figure 1 The flow chart includes the following steps:

[0035] In step S101, a design value of ammonia nitrogen removal amount of a membrane aerated biofilm reactor is obtained, and a reference air supply amount of the membrane aerated biofilm reactor is determined according to the design value of ammonia nitrogen removal amount and oxygen loss related parameters. The oxygen loss related parameters are parameters related to the loss of oxygen from the air source to the process of being utilized by microorganisms.

[0036] The membrane aerated biofilm reactor is a sewage treatment reactor that transfers oxygen to microorganisms in a biofilm through a gas permeable membrane (such as a hollow fiber membrane) and degrades pollutants by microbial metabolism. The design value of ammonia nitrogen removal amount is the expected mass of ammonia nitrogen to be removed per unit time. The oxygen loss related parameters include biofilm oxygen utilization rate, oxygen transfer efficiency, air density, mass fraction of oxygen in air, and theoretical oxygen demand per unit of ammonia nitrogen removal.

[0037] In some optional embodiments, obtaining the design value of ammonia nitrogen removal amount of the membrane aerated biofilm reactor includes: obtaining a design value of ammonia nitrogen deviation according to the difference between the design value of influent ammonia nitrogen and the design value of effluent ammonia nitrogen of the membrane aerated biofilm reactor; and obtaining the design value of ammonia nitrogen removal amount according to the product of the design value of ammonia nitrogen deviation, a preset water treatment amount, and a unit conversion coefficient. The design value of ammonia nitrogen removal amount is a preset ammonia nitrogen removal amount of the membrane aerated biofilm reactor.

[0038] The unit conversion coefficient can be .

[0039] For example, the formula for determining the design value of ammonia nitrogen removal amount is:

[0040]

[0041] wherein, is the design value of ammonia nitrogen removal amount of the MABR unit (in kilograms per hour, kg / h), is the design value of influent ammonia nitrogen of the MABR unit (in milligrams per liter, mg / L), is the design value of effluent ammonia nitrogen of the MABR unit (mg / L), is the preset water treatment amount (in cubic meters per hour, / h).

[0042] In some optional embodiments, the reference air supply amount of the membrane aerated biofilm reactor is determined according to the ammonia nitrogen removal amount design value and the oxygen loss related parameters, including: obtaining a theoretical oxygen demand according to the product of the removal unit ammonia nitrogen theoretical oxygen demand and the ammonia nitrogen removal amount design value; determining an oxygen effective supply coefficient according to the product of the biofilm oxygen utilization rate, the oxygen transfer efficiency, the air density and the mass fraction of oxygen in air; and determining the reference air supply amount according to the quotient of the theoretical oxygen demand and the oxygen effective supply coefficient.

[0043] wherein the removal unit ammonia nitrogen theoretical oxygen demand can be kgO2 / kgN (kilogram of oxygen per kilogram of nitrogen).

[0044] Exemplarily, the formula for determining the reference air supply amount is:

[0045]

[0046] wherein, the reference air supply amount is (m3 / h), the MABR unit ammonia nitrogen removal amount design value is (kg / h), the biofilm oxygen utilization rate can be 0.6-0.8, the oxygen transfer efficiency can be 30% of the ammonia nitrogen removal amount design value, the air density can be 1.293 kg / m3 (kilogram per cubic meter) in standard state, and the mass fraction of oxygen in air can be 23.2%.

[0047] Step S102, adjusting the reference air supply amount based on a preset nonlinear function according to the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value of the membrane aerated biofilm reactor, to obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor.

[0048] wherein the preset nonlinear function can be a logarithmic function, and an online ammonia nitrogen monitor is installed at the influent end of the MABR to obtain the real-time influent ammonia nitrogen concentration.

[0049] ​In some optional embodiments, the real-time feed-forward air supply amount of the membrane aerated biofilm reactor is obtained by adjusting the benchmark air supply amount based on a preset nonlinear function and the real-time influent ammonia nitrogen concentration and the design value of the influent ammonia nitrogen of the membrane aerated biofilm reactor, including: obtaining the ammonia nitrogen load fluctuation intensity according to the quotient of the real-time influent ammonia nitrogen concentration and the design value of the influent ammonia nitrogen; performing nonlinear correction on the ammonia nitrogen load fluctuation intensity by using the preset nonlinear function to obtain a nonlinear correction term of the ammonia nitrogen fluctuation; obtaining a first summation result according to the sum of the preset value and the nonlinear correction term; and obtaining the real-time feed-forward air supply amount of the membrane aerated biofilm reactor according to the product of the benchmark air supply amount and the first summation result.

[0050] Step S103, determining the real-time air supply correction amount according to the real-time tail gas oxygen content deviation of the membrane aerated biofilm reactor and the benchmark air supply amount.

[0051] The tail gas outlet end of the membrane aerated biofilm reactor is provided with an oxygen content on-line monitor for real-time monitoring of the tail gas oxygen content, so as to obtain the real-time tail gas oxygen content deviation according to the difference between the real-time monitoring tail gas oxygen content and the tail gas oxygen content threshold value. If the real-time tail gas oxygen content is lower than the tail gas oxygen content threshold value, the air supply amount needs to be increased to prevent anoxic state. If the real-time tail gas oxygen content is higher than the tail gas oxygen content threshold value (oxygen mass transfer efficiency is too low), the air supply amount needs to be reduced to save energy. Exemplarily, the tail gas oxygen content threshold value can be 16.0% to 17.5%.

[0052] In some optional embodiments, the real-time air supply correction amount is determined according to the real-time tail gas oxygen content deviation of the membrane aerated biofilm reactor and the benchmark air supply amount, including: determining a proportional term and an integral term according to the real-time tail gas oxygen content deviation; obtaining a second summation result according to the sum of the proportional term and the integral term; and obtaining the real-time air supply correction amount according to the product of the second summation result and the benchmark air supply amount.

[0053] Step S104, cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor by the real-time feed-forward air supply amount, the real-time air supply correction amount and the preset air supply amount threshold value to perform wastewater treatment.

[0054] In some optional embodiments, the target real-time air supply amount of the membrane aerated biofilm reactor is cooperatively controlled by the real-time feed-forward air supply amount, the real-time air supply correction amount and the preset air supply amount threshold value to perform wastewater treatment, including: cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor to perform wastewater treatment according to the sum of the real-time feed-forward air supply amount and the real-time air supply correction amount, with the preset air supply amount threshold value as a constraint.

[0055] The sewage treatment method based on air supply amount control provided in the embodiment obtains an ammonia nitrogen removal amount design value of a membrane aerated biofilm reactor, determines a reference air supply amount of the membrane aerated biofilm reactor according to the ammonia nitrogen removal amount design value and oxygen loss related parameters, considers the oxygen transfer loss in the aeration process, so that the reference air supply amount is more suitable to the actual situation and more accurate. According to a preset nonlinear function, the embodiment adjusts the reference air supply amount according to the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value of the membrane aerated biofilm reactor, and obtains a real-time feedforward air supply amount of the membrane aerated biofilm reactor. Through real-time monitoring of the influent ammonia nitrogen concentration, the embodiment introduces the preset nonlinear function to process the ammonia nitrogen load fluctuation intensity, avoids overcompensation in the high concentration interval, adjusts the air supply amount in time when the influent ammonia nitrogen concentration suddenly changes, obtains the real-time feedforward air supply amount, overcomes the hysteresis problem of single feedback control, and improves the response speed of the MABR air supply amount adjustment. According to the real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor, the embodiment determines a real-time air supply correction amount. Through real-time monitoring of the tail gas oxygen content deviation, the embodiment obtains the real-time air supply correction amount, and improves the accuracy of the real-time air supply correction amount. Through dynamic correction of the air supply amount according to the tail gas oxygen content deviation, the embodiment eliminates the model error and external disturbance. Through the real-time feedforward air supply amount, the real-time air supply correction amount and a preset air supply amount threshold, the embodiment cooperatively controls the target real-time air supply amount of the membrane aerated biofilm reactor for sewage treatment. The preset air supply amount threshold is used to limit the air supply amount range, so as to avoid waste or shortage of the air supply amount caused by continuous error. According to the cooperative control of the real-time feedforward air supply amount and the real-time air supply correction amount, the disturbance such as membrane pollution and biofilm thickness change is effectively inhibited, the air supply redundancy during the low load period of the influent ammonia nitrogen is avoided, the air supply is insufficient during the high load period, the energy consumption waste caused by the air supply is reduced, the accuracy of the target real-time air supply amount is improved, the stability of the sewage treatment is improved, and the effect of the sewage treatment is optimized.

[0056] In the embodiment, a sewage treatment method based on air supply amount control is provided, which can be used for a computer device for controlling a membrane aerated biofilm reactor, Figure 2 is a flowchart of another sewage treatment method based on air supply amount control according to the embodiment of the present application, as shown in Figure 2 , the flowchart includes the following steps:

[0057] In step S201, an ammonia nitrogen removal amount design value of a membrane aerated biofilm reactor is obtained, and a reference air supply amount of the membrane aerated biofilm reactor is determined according to the ammonia nitrogen removal amount design value and oxygen loss related parameters. The oxygen loss related parameters are parameters related to the loss of oxygen from the gas source to the process of being utilized by microorganisms. For details, refer to step S101 of the embodiment shown in Figure 1 , which will not be described here again.

[0058] Step S202 , based on a preset nonlinear function, the reference air supply is adjusted according to the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value of the membrane aeration biofilm reactor to obtain the real-time feedforward air supply of the membrane aeration biofilm reactor.

[0059] Specifically, the above step S202 includes:

[0060] Step S2021, obtaining the ammonia nitrogen load fluctuation intensity according to the quotient of the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value.

[0061] Step S2022: Perform nonlinear correction on the ammonia nitrogen load fluctuation intensity using a preset nonlinear function to obtain a nonlinear correction term for ammonia nitrogen fluctuation.

[0062] Step S2023: Obtain a first summation result based on the sum of the preset value and the nonlinear correction term.

[0063] Step S2024: obtaining the real-time feedforward gas supply of the membrane aerated biofilm reactor according to the product of the reference gas supply and the first summation result.

[0064] For example, the formula for determining the real-time feedforward gas supply volume is:

[0065]

[0066] in, is the real-time feedforward air supply (kg / h), is the base gas supply ( / h), is the real-time influent ammonia nitrogen concentration (mg / L), is the design value of ammonia nitrogen in the influent (mg / L), is the fluctuation intensity of ammonia nitrogen load.

[0067] In some optional embodiments, the real-time feedforward gas supply adopts a logarithmic model to solve the nonlinear relationship between the ammonia nitrogen load and the gas supply, thereby avoiding the over-compensation problem in the high concentration range.

[0068] Step S203 , determining a real-time air supply correction amount according to the real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aeration biofilm reactor.

[0069] Specifically, the above step S203 includes:

[0070] Step S2031: Determine the proportional term and the integral term based on the real-time exhaust oxygen content deviation.

[0071] Step S2032: Obtain a second summation result based on the sum of the proportional term and the integral term.

[0072] Step S2033, obtaining the real-time air supply correction amount according to the product of the second summation result and the reference air supply amount.

[0073] Exemplarily, the formula for determining the real-time air supply correction amount is:

[0074]

[0075] wherein, is the real-time air supply correction amount (kg / h), is the oxygen content threshold of the tail gas, which can be 16.0% to 17.5%, is the real-time oxygen content of the tail gas, is the reference air supply amount (kg / h).

[0076] Step S204, cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor for wastewater treatment by the real-time feedforward air supply amount, the real-time air supply correction amount, and the preset air supply amount threshold.

[0077] Specifically, the above step S204 includes:

[0078] Step S2041, cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor for wastewater treatment by the sum of the real-time feedforward air supply amount and the real-time air supply correction amount, with the preset air supply amount threshold as a constraint.

[0079] Exemplarily, the formula for cooperatively controlling the target real-time air supply amount of the membrane aerated biofilm reactor for wastewater treatment is:

[0080]

[0081] wherein, is the target real-time air supply amount (kg / h), is the limiting function, is the real-time feedforward air supply amount (kg / h), is the real-time air supply correction amount (kg / h), is the lower limit of the preset air supply amount threshold, is the upper limit of the preset air supply amount threshold.

[0082] In some optional embodiments, setting the upper and lower limits of the air supply amount threshold can prevent membrane damage or biofilm anoxia caused by excessive adjustment of the air supply amount.

[0083] In some optional embodiments, is 0.3 to 0.6 times the reference air supply amount, is 1.4 to 1.6 times the reference air supply amount.

[0084] ​The sewage treatment method based on air supply amount control provided in the embodiment introduces a logarithmic function to process the nonlinear relationship of ammonia nitrogen load fluctuation, avoids over-compensation in the high concentration interval, introduces a logarithmic function to process the nonlinear relationship of ammonia nitrogen load fluctuation, avoids over-compensation in the high concentration interval, and the embodiment of the present application combines dynamic constraints and a nonlinear compensation function (such as a logarithmic model) to accurately match the air / oxygen demand of air supply and actual ammonia nitrogen removal, avoid air supply redundancy in the low load period, and air supply shortage in the high load period. The feedforward-feedback double closed-loop cooperative control architecture of the present application can effectively suppress disturbances such as membrane fouling and biological membrane thickness changes, improve the stability of the sewage treatment system, use parameters based on actual operation data for regulation and control, does not need to rely on complex mechanism models, reduces the implementation cost, and can adapt to different water quality fluctuation scenarios, and has strong universality.

[0085] In the embodiment, a sewage treatment device based on air supply amount control is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware implementation is also possible and contemplated.

[0086] The embodiment provides a sewage treatment device based on air supply amount control, as shown in Figure 3 , comprising:

[0087] The reference determination module 301 is configured to obtain a design value of ammonia nitrogen removal amount of the membrane aerated biofilm reactor, and determine a reference air supply amount of the membrane aerated biofilm reactor according to the design value of ammonia nitrogen removal amount and an oxygen loss related parameter.

[0088] The feedforward control module 302 is configured to adjust the reference air supply amount based on a preset nonlinear function according to a real-time influent ammonia nitrogen concentration and a design value of influent ammonia nitrogen of the membrane aerated biofilm reactor, and obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor.

[0089] The feedback control module 303 is configured to determine a real-time air supply correction amount according to a real-time tail gas oxygen content deviation and the reference air supply amount of the membrane aerated biofilm reactor.

[0090] The air supply amount synthesis module 304 is configured to cooperatively control a target real-time air supply amount of the membrane aerated biofilm reactor by the real-time feedforward air supply amount, the real-time air supply correction amount, and a preset air supply amount threshold to perform sewage treatment.

[0091] In some optional embodiments, the reference determination module 301 comprises:

[0092] The ammonia-nitrogen deviation determination unit is configured to determine an ammonia-nitrogen deviation design value according to a difference between the design value of the ammonia-nitrogen in the influent and the design value of the ammonia-nitrogen in the effluent of the membrane aerated biofilm reactor.

[0093] The removal amount determination unit is configured to determine an ammonia-nitrogen removal amount design value according to a product of the ammonia-nitrogen deviation design value, a preset treatment water amount, and a unit conversion coefficient; and the ammonia-nitrogen removal amount design value is a preset ammonia-nitrogen removal amount of the membrane aerated biofilm reactor.

[0094] The oxygen demand determination unit is configured to determine a theoretical oxygen demand according to a product of a theoretical oxygen demand per unit of ammonia-nitrogen removal and the ammonia-nitrogen removal amount design value.

[0095] The coefficient determination unit is configured to determine an oxygen effective supply coefficient according to a product of a biofilm oxygen utilization rate, an oxygen transfer efficiency, an air density, and a mass fraction of oxygen in the air.

[0096] The reference air supply amount determination unit is configured to determine a reference air supply amount according to a quotient of the theoretical oxygen demand and the oxygen effective supply coefficient.

[0097] In some optional embodiments, the feedforward control module 302 includes:

[0098] The load relationship determination unit is configured to determine an ammonia-nitrogen load fluctuation intensity according to a quotient of the real-time ammonia-nitrogen concentration in the influent and the design value of the ammonia-nitrogen in the influent.

[0099] The nonlinear correction unit is configured to perform nonlinear correction on the ammonia-nitrogen load fluctuation intensity by using a preset nonlinear function to obtain a nonlinear correction term of the ammonia-nitrogen fluctuation.

[0100] The first summation unit is configured to obtain a first summation result according to a sum of a preset value and the nonlinear correction term.

[0101] The product unit is configured to obtain a real-time feedforward air supply amount of the membrane aerated biofilm reactor according to a product of the reference air supply amount and the first summation result.

[0102] In some optional embodiments, the feedback control module 303 includes:

[0103] The proportional-integral unit is configured to determine a proportional term and an integral term according to the real-time tail gas oxygen content deviation.

[0104] The second summation unit is configured to obtain a second summation result according to a sum of the proportional term and the integral term.

[0105] The feedback control unit is configured to obtain a real-time air supply correction amount according to a product of the second summation result and the reference air supply amount.

[0106] In some optional embodiments, the air supply amount synthesis module 304 includes:

[0107] The air supply synthesis unit is used to collaboratively control the target real-time air supply of the membrane aeration biofilm reactor for sewage treatment based on the sum of the real-time feedforward air supply and the real-time air supply correction amount, with a preset air supply threshold as a constraint.

[0108] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0109] The sewage treatment device based on air supply volume control in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0110] The embodiment of the present invention also provides a computer device having the above Figure 3 The sewage treatment plant shown is based on air supply volume control.

[0111] See also Figure 4 , Figure 4 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 4 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 4 A processor 10 is taken as an example.

[0112] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0113] The memory 20 stores instructions executable by the at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0114] The memory 20 can include a program storage area and a data storage area. The program storage area can store an operating system and applications required by at least one function. The data storage area can store data created according to the use of the computer device, and the like. In addition, the memory 20 can include a high-speed random access memory, and can also include a non-transitory memory such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device. In some optional embodiments, the memory 20 can optionally include a memory disposed remotely with respect to the processor 10, and these remote memories can be connected to the computer device through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0115] The memory 20 can include a volatile memory such as a random access memory, and can also include a non-volatile memory such as a flash memory, a hard disk, or a solid-state disk. The memory 20 can also include a combination of the above-mentioned kinds of memories.

[0116] The computer device further includes a communication interface 30 for communication of the computer device with other devices or communication networks.

[0117] The embodiments of the present application also provide a computer readable storage medium. The above method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or implemented as computer code originally stored in a remote storage medium or a non-transitory machine readable storage medium and downloaded to a local storage medium, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special purpose hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state disk, and the like. Further, the storage medium can also include a combination of the above-mentioned kinds of memories. It can be understood that the computer, the processor, the microprocessor controller, or the programmable hardware includes a storage component that can store or receive software or computer code, when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0118] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, can invoke or provide the method and / or technical solutions according to the present application. Those skilled in the art should understand that the form of computer program instructions in computer readable medium includes but is not limited to source files, executable files, installation package files and the like, and accordingly, the way of computer program instructions executed by computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0119] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A sewage treatment method based on air supply control, characterized in that: The method comprises: According to the difference between the design value of ammonia nitrogen in the inlet and the design value of ammonia nitrogen in the outlet of the membrane aeration biofilm reactor, the design value of ammonia nitrogen deviation is obtained; According to the product of the ammonia nitrogen deviation design value, the preset treated water volume and the unit conversion coefficient, the ammonia nitrogen removal design value is obtained; the ammonia nitrogen removal design value is the preset ammonia nitrogen removal amount of the membrane aeration biofilm reactor; The theoretical oxygen demand is obtained by multiplying the theoretical oxygen demand for removing unit ammonia nitrogen by the design value of the ammonia nitrogen removal amount; The oxygen effective supply coefficient is determined based on the product of biofilm oxygen utilization rate, oxygen mass transfer efficiency, air density and the mass fraction of oxygen in the air; determining a reference gas supply according to a quotient of the theoretical oxygen demand and the oxygen effective supply coefficient; Obtaining the ammonia nitrogen load fluctuation intensity according to the quotient of the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value; Performing a nonlinear correction on the ammonia nitrogen load fluctuation intensity using a preset nonlinear function to obtain a nonlinear correction term for ammonia nitrogen fluctuation; Obtaining a first summation result according to the sum of 1 and the nonlinear correction term; Obtaining a real-time feedforward air supply of the membrane aerated biofilm reactor according to a product of the reference air supply and the first summation result; Determine the proportional term and the integral term based on the real-time exhaust oxygen content deviation; Obtaining a second summation result according to the sum of the proportional term and the integral term; Obtaining a real-time air supply correction amount according to the product of the second summation result and the reference air supply amount; The target real-time air supply volume of the membrane aeration biofilm reactor is collaboratively controlled through the real-time feedforward air supply volume, the real-time air supply correction volume and the preset air supply volume threshold to perform sewage treatment.

2. The method according to claim 1, characterized in that The method of collaboratively controlling the target real-time air supply of the membrane aeration biofilm reactor to treat sewage by using the real-time feedforward air supply, the real-time air supply correction amount, and the preset air supply threshold comprises: With the preset air supply threshold as a constraint, the target real-time air supply of the membrane aerated biofilm reactor is collaboratively controlled according to the sum of the real-time feedforward air supply and the real-time air supply correction amount to perform sewage treatment.

3. A sewage treatment device based on air supply control, characterized in that: The device for executing the sewage treatment method based on air supply control according to claim 1 comprises: a benchmark determination module for obtaining a design value for ammonia nitrogen removal of a membrane aerated biofilm reactor and determining a benchmark air supply for the membrane aerated biofilm reactor based on the design value for ammonia nitrogen removal and oxygen loss-related parameters; the oxygen loss-related parameters are parameters related to the loss of oxygen from the gas source to utilization by microorganisms; the oxygen loss-related parameters include biofilm oxygen utilization rate, oxygen mass transfer efficiency, air density, mass fraction of oxygen in the air, and theoretical oxygen demand for removing a unit of ammonia nitrogen; a feedforward control module for adjusting the reference air supply based on a preset nonlinear function and the real-time influent ammonia nitrogen concentration and the influent ammonia nitrogen design value of the membrane aeration biofilm reactor to obtain the real-time feedforward air supply of the membrane aeration biofilm reactor; A feedback control module is used to determine a real-time air supply correction amount according to a real-time tail gas oxygen content deviation of the membrane aeration biofilm reactor and the reference air supply amount; The air supply synthesis module is used to collaboratively control the target real-time air supply of the membrane aeration biofilm reactor for sewage treatment through the real-time feedforward air supply, the real-time air supply correction and the preset air supply threshold.

4. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the sewage treatment method based on air supply control according to any one of claims 1 to 2 by executing the computer instructions.

5. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the sewage treatment method based on air supply volume control according to any one of claims 1 to 2.

6. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the sewage treatment method based on air supply volume control according to any one of claims 1 to 2.

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