Aeration system and method for sewage treatment

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to an aeration system and method for sewage treatment.The aeration system comprises a mounting unit fixedly arranged at one end, a mounting cylinder fixedly arranged at the other end of the mounting unit, an adjusting motor fixedly arranged at the upper end of the mounting cylinder, an adjusting cylinder rotationally sleeved with the mounting cylinder, and an output shaft of the adjusting motor fixedly connected with the adjusting cylinder; an adjusting rod is sleeved with the adjusting cylinder, the adjusting cylinder is in threaded connection with the adjusting rod, a supporting pipe is fixedly connected to the lower end of the adjusting rod, a submersible motor is installed on the supporting pipe, an output shaft of the submersible motor is connected with an aeration rod, an impeller is arranged on the aeration rod, and the submersible motor is connected with the oxygenation unit. Through the structural design of the mounting unit, the adjusting cylinder and the adjusting rod, the working depth of the impeller is dynamically matched with the sewage dissolved oxygen demand, the problem of invalid aeration caused by fixed mounting of a traditional aeration device is solved, and energy waste caused by continuous full-load operation is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and particularly relates to an aeration system and method for sewage treatment. Background Art

[0002] In the process of sewage biochemical treatment, the aeration link undertakes the core function of providing dissolved oxygen required for biochemical reactions for microorganisms in activated sludge, and its technical efficiency directly affects the efficiency and operating cost of the entire sewage treatment system. As a key link in the biological treatment process, the activated sludge method decomposes organic matter into inorganic matter through the aerobic respiration of microorganisms, and the aeration process is the core guarantee for maintaining this biochemical reaction.

[0003] There are still certain problems in the existing aeration device technology: the energy consumption structure is unbalanced, and the energy consumption of the aeration link accounts for 50%-70% of the total energy consumption of sewage treatment. The excessive oxidation phenomenon caused by continuous aeration of traditional equipment results in waste of electric energy; the mass transfer efficiency is low, and the insufficient air delivery pressure limits the oxygen dissolution rate, making it difficult to meet the oxygen demand of microorganisms under complex water quality conditions; the degree of automation lags behind. The control mode of the existing aeration device usually adopts timing control or adjustment according to the dissolved oxygen concentration. When the timing control strategy is adopted, the water quality fluctuation cannot be monitored and responded to in real time; when the strategy of adjusting according to the dissolved oxygen concentration is adopted, due to the large lag in sensor detection, the adjustment of the aeration volume is not timely, resulting in the problem of hypoxia in the front-stage aeration and oxygen surplus in the rear-stage aeration. Summary of the Invention

[0004] The present invention aims at the problems in the existing technology, and provides an aeration system and method for sewage treatment, which solves the problem that the control mode of the traditional aeration device in the existing technology adopting the form of timing control or adjustment according to the dissolved oxygen concentration cannot respond to water quality fluctuations in real time, and has a large detection lag, thus leading to hypoxia in the front stage and oxygen surplus in the rear stage.

[0005] The technical solution adopted by the present invention is as follows: In a first aspect, the present application provides an aeration system for sewage treatment, including a fixedly arranged installation cylinder, an adjustment motor fixedly arranged at the upper end of the installation cylinder, an adjustment cylinder rotatably sleeved in the installation cylinder, the output shaft of the adjustment motor is fixedly connected to the adjustment cylinder, an adjustment rod is sleeved in the adjustment cylinder, the adjustment cylinder is threadedly connected to the adjustment rod, a support pipe is fixedly connected to the lower end of the adjustment rod, a submersible motor is installed on the support pipe, the output shaft of the submersible motor is connected to an aeration rod, an impeller is arranged on the aeration rod, and an oxygenation unit is further arranged in the aeration system, and the oxygenation unit is communicated with the submersible motor for supplying oxygen to the aeration system.

[0006] Preferably, the oxygenation unit includes a blower and an oxygenation pipe. One end of the oxygenation pipe is connected to the blower. The oxygenation unit further includes a gas-liquid mixing chamber, which is fixedly arranged at the lower end of the submersible motor. The other end of the oxygenation pipe is communicated with the gas-liquid mixing chamber.

[0007] Preferably, the oxygenation pipe is a silicone hose, and a gas flow rate control module is arranged on the oxygenation pipe for controlling the gas flow rate in the oxygenation pipe.

[0008] Preferably, a plurality of first through holes are formed in the outer shell of the submersible motor, and a plurality of second through holes are formed in the gas-liquid mixing chamber.

[0009] Preferably, a flow collector is fixedly connected to the lower end of the gas-liquid mixing chamber through a diameter-changing unit, and the lower end of the flow collector is located below the impeller.

[0010] Preferably, a dissolved oxygen sensor is installed inside the flow collector or the diameter-changing unit for monitoring the DO value of the liquid discharged from the gas-liquid mixing chamber.

[0011] Preferably, a control unit is further included, which is respectively connected to the dissolved oxygen sensor, the regulating motor, the submersible motor, and the gas flow rate control module.

[0012] Preferably, the aeration system further includes a mounting unit. One end of the mounting unit is fixedly connected to the mounting cylinder, and the other end of the mounting unit is used for connecting to the outside.

[0013] In a second aspect, the present application provides an aeration method for sewage treatment, using the aeration system for sewage treatment described in the first aspect, including the following steps: Step S1: The regulating motor adjusts the flow collector to the lowest height state, and the control unit obtains the monitoring data of the dissolved oxygen sensor and the gas flow rate control module; Step S2: Input a preset DO value into the control unit; Step S3: The control unit calculates the input value of the gas flow rate control module by using proportional-integral-derivative according to the preset DO value and the actual monitoring value, and sends a signal to the gas flow rate control module for regulation, and monitors the change rate of the DO value within a time window; Step S4: The control unit obtains the data of the regulating motor. When the flow collector is in the highest height state, jump to step S6, otherwise jump to step S5; Step S5: Adjust the regulating motor with a step size of a to increase the height of the flow collector, and jump to step S3 after each adjustment; Step S6: Select the data of the regulating motor corresponding to the maximum change rate of the DO value as the working data.

[0014] Preferably, in step S3, the proportional-integral-derivative control law is:

[0015] Among them, is the control output, that is, the gas flow rate value of the gas volume regulation module; is the proportional gain; is the integral time constant; is the derivative time constant; is the error signal, that is, the difference signal between the preset DO value and the actual monitoring value.

[0016] It can be seen from the above technical solutions that the present application has the following advantages: 1. Through the structural design of the installation unit - adjusting cylinder - adjusting rod, when the adjusting motor drives the adjusting cylinder to rotate, the screw transmission mechanism can accurately control the vertical displacement of the support pipe and the aeration unit, so that the working depth of the impeller dynamically matches the sewage dissolved oxygen demand. This structure effectively overcomes the problem of ineffective aeration caused by the fixed installation of traditional aeration devices and avoids energy waste caused by continuous full-load operation; at the same time, a local turbulence is formed by driving the impeller with a submersible motor, and the gas-liquid mixing efficiency is enhanced by cooperating with the height adjustment function; the coordinated work of the adjusting motor and the control unit provides a mechanical execution basis for intelligent aeration control.

[0017] 2. A dual-power collaborative oxygen supply mechanism is formed by the blower and the submersible motor through the oxygen supply pipe. The blower provides a high-pressure gas basic oxygen source, and the rotation of the impeller of the submersible motor generates a negative pressure suction effect. The superposition of the two realizes the coupling enhancement of the gas transmission pressure and the liquid disturbance intensity, compared with a single mechanical aeration or blower aeration system.

[0018] 3. The flexible characteristics of the silicone hose can adapt to the pipeline deformation requirements during the height adjustment of the aeration unit, avoiding the risk of interface leakage or rupture caused by mechanical displacement of traditional rigid pipes; the gas volume regulation module forms a closed-loop control of gas supply by detecting the gas flow rate in real time and feeding it back to the control unit, ensuring the dynamic balance between the aeration intensity and the microbial oxygen demand, and reducing the frequency of manual intervention.

[0019] 4. The setting of the gas-liquid mixing chamber constructs a primary gas diffusion zone, and the large bubbles are broken into small bubbles through the turbulent shear action inside the cavity, significantly increasing the gas-liquid contact specific surface area.

[0020] 5. By setting the first through hole and the second through hole, it is convenient for liquid flow, and there is no need to suck liquid at the bottom for mixing, improving the mixing efficiency. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Structural schematic diagram of the aeration system for sewage treatment shown in the embodiment; Figure 2 Flow chart of the aeration method for sewage treatment shown in the embodiment.

[0023] In the figure: 1, installation unit; 2, installation cylinder; 3, adjustment cylinder; 4, first diameter change; 5, submersible motor; 6, gas-liquid mixing chamber; 7, dissolved oxygen sensor; 8, second diameter change; 9, impeller; 10, support pipe; 11, flow collector; 12, oxygenation pipe; 13, gas volume regulation module; 14, control unit; 15, upper computer; 16, first through hole; 17, second through hole; 18, blower; 19, third diameter change; 20, adjustment motor; 21, internal thread; 22, adjustment rod; 23, aeration rod. Specific embodiments

[0024] In order to make the application purpose, features, and advantages of the present application more obvious and understandable, the technical solutions protected by the present application will be clearly and completely described below by using specific embodiments and accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this patent.

[0025] In the process of sewage biochemical treatment, the aeration link undertakes the core function of providing dissolved oxygen required for biochemical reactions for microorganisms in activated sludge, and its technical efficiency directly affects the efficiency and operating cost of the entire sewage treatment system. As a key link in the biological treatment process, the activated sludge method decomposes organic matter into inorganic matter through the aerobic respiration of microorganisms, and the aeration process is the core guarantee for maintaining this biochemical reaction.

[0026] Aeration not only needs to achieve efficient mass transfer between gas and liquid, ensure the full diffusion of oxygen molecules and form a dynamic mixing system with microorganisms and substrates, but also optimize the microbial metabolic environment by precisely controlling the dissolved oxygen (DO) concentration.

[0027] There are still certain problems in the existing blower aeration and mechanical aeration technologies: the energy consumption structure is unbalanced, and the energy consumption of the aeration link accounts for 50%-70% of the total energy consumption of sewage treatment. The excessive oxidation phenomenon caused by continuous aeration of traditional equipment results in waste of electric energy; the mass transfer efficiency is low, and the limited air delivery pressure restricts the oxygen dissolution rate, making it difficult to meet the oxygen demand of microorganisms under complex water quality conditions; the degree of automation lags behind, and the control mode of the existing aeration device cannot respond to water quality fluctuations in real time, resulting in problems such as hypoxia in the front section and oxygen surplus in the rear section.

[0028] The present invention addresses the problems in the prior art and provides an aeration system and method for sewage treatment, solving the problem in the prior art that the control mode of traditional aeration devices cannot respond to water quality fluctuations in real time, resulting in hypoxia in the front section and oxygen surplus in the rear section.

[0029] The present application provides an aeration system for sewage treatment, including an installation unit 1 fixedly arranged at one end. The other end of the installation unit 1 is fixedly provided with an installation cylinder 2. The outer side wall of the installation cylinder 2 is fixedly connected to the installation unit 1. An adjustment motor 20 is fixedly arranged at the upper end of the installation cylinder 2. An adjustment cylinder 3 is rotatably sleeved in the installation cylinder 2. The output shaft of the adjustment motor 20 is fixedly connected to the adjustment cylinder 3. An adjustment rod 22 is sleeved in the adjustment cylinder 3. The adjustment cylinder 3 is threadedly connected to the adjustment rod 22. The lower end of the adjustment rod 22 is fixedly connected to a support pipe 10. A submersible motor 5 is installed on the support pipe 10. The output shaft of the submersible motor 5 is connected to an aeration rod 23. An impeller 9 is arranged on the aeration rod 23. The aeration system is also provided with an oxygenation unit, and the oxygenation unit is communicated with the submersible motor 5 for supplying oxygen to the aeration system.

[0030] The submersible motor 5 is installed on the support pipe 10 through a first reducer 4.

[0031] Through the structural design of the installation unit 1 - adjustment cylinder 3 - adjustment rod 22, when the adjustment motor 20 drives the adjustment cylinder 3 to rotate, the threaded transmission mechanism can accurately control the vertical displacement of the support pipe 10 and the aeration unit, enabling the working depth of the impeller 9 to be dynamically matched with the dissolved oxygen demand of the sewage. This structure effectively overcomes the problem of ineffective aeration caused by the fixed installation of traditional aeration devices, avoiding energy waste caused by continuous full-load operation. At the same time, the submersible motor 5 drives the impeller 9 to form local turbulence, and the height adjustment function is used to enhance the gas-liquid mixing efficiency. The coordinated work of the adjustment motor 20 and the control unit 14 provides a mechanical execution basis for intelligent aeration control.

[0032] The installation unit 1 is made of duplex stainless steel and is surface-treated by sandblasting and passivation to form an anti-corrosion layer. The fixed end of the installation unit 1 is configured with a universal adjustment flange, allowing an angular deflection of ±15° in the vertical direction to adapt to the installation requirements of different tank structures. The free end of the installation unit 1 is connected to a cylindrical installation cylinder 2 by hot melt welding. The inner wall of the cylinder is machined with a precision guiding groove, which forms a sliding fit with the protruding guide rail on the outer wall of the adjustment cylinder 3.

[0033] The adjustment motor 20 is a closed-loop stepper motor and is rigidly connected to the top of the installation cylinder 2 through a flange mounting seat. The end of the output shaft of the motor is machined with a D-shaped section, which forms a keyless connection with the D-shaped groove at the top of the adjustment cylinder 3.

[0034] The adjustment cylinder 3 is cast from high-strength aluminum bronze. The inner wall is machined with a trapezoidal internal thread 21, and the threaded working surface is nitrided to form a wear-resistant layer with a hardness of HRC60.

[0035] The outer surface of the adjusting rod 22 is processed with a thread pair matching the adjusting cylinder 3, and the thread contact surface is coated with a molybdenum disulfide solid lubricating film to reduce the friction coefficient.

[0036] The support pipe 10 adopts a segmented combined structure, the upper pipe section is connected to the adjustment rod 22 through a tapered thread, and an anaerobic thread locking agent is applied to the mating surface to prevent loosening.

[0037] The submersible motor 5 is a permanent magnet synchronous underwater power device, and the housing is integrally cast with 316L stainless steel. The motor output shaft is connected to the aeration rod 23 through an involute spline.

[0038] The aeration rod 23 is a variable-section shaft-like component; a six-blade swept impeller 9 is installed at the bottom, and the blades adopt an airfoil profile, and the installation angle is 45° adjustable. A guide cover is set on the periphery of the impeller 9, and the gap between the cover and the blade tip is maintained at 1.5 mm, forming a Venturi effect acceleration channel.

[0039] In some embodiments, the oxygenation unit includes a blower 18 and an oxygenation tube 12 , one end of the oxygenation tube 12 is connected to the blower 18 , and the other end is disposed between the submersible motor 5 and the impeller 9 .

[0040] The blower 18 and the submersible motor 5 form a dual-power synergistic oxygen supply mechanism through the oxygenation pipe 12. The blower 18 provides a high-pressure gas basic oxygen source, and the impeller 9 of the submersible motor 5 rotates to produce a negative pressure suction effect. The two are superimposed to achieve the coupling enhancement of gas delivery pressure and liquid disturbance intensity, compared with a single mechanical aeration or blast aeration system.

[0041] The oxygenation unit adopts a dual-source gas supply mode, including a high-pressure gas source device, a flexible gas pipeline and an efficient gas-liquid mixing device. The blower 18 uses a three-stage centrifugal booster unit, and a cyclone separator is set at the outlet to remove oil and water impurities. The oxygenation pipe 12 adopts a four-layer composite structure silicone hose, lined with an antibacterial coating, a middle interlayer woven Kevlar reinforced fiber, and an outer layer covered with a polyurethane wear-resistant sheath.

[0042] The gas volume control module 13 integrates a thermal mass flow meter and an electric ball valve, with a flow detection resolution of 0.1 cubic meters per hour and a valve opening adjustment accuracy of ±0.5%. The module has a built-in PID controller with a sampling period of 100 milliseconds, which can adjust the gas flow in real time according to the set value. The gas-liquid mixing chamber 6 is a diffusion structure with a honeycomb guide grid inside.

[0043] In some embodiments, the oxygenation tube 12 is a silicone hose, and a gas volume control module 13 is disposed on the oxygenation tube 12 . The gas volume control module 13 is used to control the gas flow rate in the oxygenation tube 12 .

[0044] The flexible feature of the silicone hose can adapt to the pipeline deformation requirements during the height adjustment of the aeration unit, avoiding the risk of interface leakage or rupture caused by mechanical displacement of traditional rigid pipelines; the gas volume control module 13 forms a closed-loop control of gas supply by detecting the gas flow rate in real time and feeding it back to the control unit 14, ensuring the dynamic balance between the aeration intensity and the oxygen demand of microorganisms and reducing the frequency of manual intervention.

[0045] In some embodiments, the oxygenation unit further includes a gas-liquid mixing chamber 6, which is fixedly arranged at the lower end of the submersible motor 5, and the other end of the oxygenation pipe 12 communicates with the gas-liquid mixing chamber 6.

[0046] The setting of the gas-liquid mixing chamber 6 constructs a primary gas diffusion zone, which breaks large air bubbles into small air bubbles through the turbulent shear action inside the cavity, significantly increasing the specific surface area of gas-liquid contact.

[0047] In some embodiments, a plurality of first through holes 16 are provided on the outer shell of the submersible motor 5, and a plurality of second through holes 17 are provided on the gas-liquid mixing chamber 6.

[0048] Through the first through holes 16 and the second through holes 17 provided, the liquid flow can be facilitated, and there is no need to suck the liquid at the bottom for mixing, improving the mixing efficiency.

[0049] In some embodiments, the lower end of the gas-liquid mixing chamber 6 is fixedly connected with a flow collector 11 through a diameter-changing unit, and the lower end of the flow collector 11 is located below the impeller 9.

[0050] The diameter-changing unit includes a second diameter-changing part 8 and a third diameter-changing part 19.

[0051] In some embodiments, a dissolved oxygen sensor 7 is installed inside the flow collector 11 or the diameter-changing unit, and the dissolved oxygen sensor 7 is used to monitor the DO value of the liquid discharged from the gas-liquid mixing chamber 6.

[0052] In some embodiments, it further includes a control unit 14, and the control unit 14 is respectively connected to the dissolved oxygen sensor 7, the regulating motor 20, the submersible motor 5, the gas volume control module 13 and the upper computer 15. In some embodiments, the present application provides a sewage treatment aeration method, which adopts the sewage treatment aeration system described in the first aspect, including the following steps: Step S1: The regulating motor adjusts the flow collector to the lowest height state, and the control unit obtains the monitoring data of the dissolved oxygen sensor and the gas volume control module, and obtains the control data of the gas volume control module; Step S2: Input a preset DO value into the control unit; Step S3: The control unit calculates the input value of the gas volume control module by using proportional integral differential according to the preset DO value and the actual monitoring value, and sends a signal to the gas volume control module for regulation, and monitors the change rate of the DO value within the time window; Step S4: The control unit obtains the data of the adjustment motor. When the current collector cover is in the highest height state, jump to step S6; otherwise, jump to step S5. Step S5: Adjust the adjustment motor with a step size of a to increase the height of the current collector cover, and jump to step S3 after each adjustment. Step S6: Select the data of the adjustment motor corresponding to the maximum change rate of the DO value as the working data.

[0053] Preferably, in step S3, the proportional-integral-derivative control law is:

[0054] where is the control output, that is, the gas flow rate value of the gas volume regulation module; is the proportional gain; is the integral time constant; is the derivative time constant; is the error signal, that is, the difference signal between the preset DO value and the actual monitored value.

[0055] It can be understood that the systems, devices, modules or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, and the specific form of the computer can be a personal computer, a laptop computer, a personal digital assistant, a tablet computer, a wearable device, or a combination of any several of these devices.

[0056] In a typical configuration, a computer includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0057] The memory may include non-permanent memory in the computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0058] Computer-readable media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0059] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0060] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0061] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0062] The terms used in one or more embodiments of this specification are for the purpose of describing particular embodiments only and are not intended to limit one or more embodiments of this specification. The singular forms "a", "the", and "said" used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0063] It should be understood that although the terms first, second, third, etc. may be used in one or more embodiments of this specification to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of one or more embodiments of this specification, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "upon" or "in response to determining".

[0064] The above description is only the preferred embodiment of one or more embodiments of this specification and is not intended to limit one or more embodiments of this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of one or more embodiments of this specification shall be included within the scope of protection of one or more embodiments of this specification.

Claims

1. An aeration system for sewage treatment, characterized in that, It includes an installation cylinder (2) fixedly arranged, with an adjustment motor (20) fixedly installed at the upper end of the installation cylinder (2). An adjustment cylinder (3) is rotatably sleeved inside the installation cylinder (2). The output shaft of the adjustment motor (20) is fixedly connected to the adjustment cylinder (3). An adjustment rod (22) is sleeved inside the adjustment cylinder (3), and the adjustment cylinder (3) is threadedly connected to the adjustment rod (22). The lower end of the adjustment rod (22) is fixedly connected to a support pipe (10). A submersible motor (5) is installed on the support pipe (10). The output shaft of the submersible motor (5) is connected to an aeration rod (23). An impeller (9) is arranged on the aeration rod (23). The aeration system is also provided with an oxygenation unit, and the oxygenation unit is communicated with the submersible motor (5) for supplying oxygen to the aeration system.

2. The aeration system for sewage treatment according to claim 1, characterized in that, The oxygenation unit includes a blower (18) and an oxygenation pipe (12). One end of the oxygenation pipe (12) is connected to the blower (18). The oxygenation unit also includes a gas-liquid mixing chamber (6), and the gas-liquid mixing chamber (6) is fixedly arranged at the lower end of the submersible motor (5). The other end of the oxygenation pipe (12) is communicated with the gas-liquid mixing chamber (6).

3. The aeration system for sewage treatment according to claim 2, characterized in that, The oxygenation pipe (12) is a silica gel material hose, and a gas flow rate control module (13) is arranged on the oxygenation pipe (12). The gas flow rate control module (13) is used to control the gas flow rate in the oxygenation pipe (12).

4. The aeration system for sewage treatment according to claim 2, wherein A number of first through holes (16) are opened on the outer shell of the submersible motor (5), and a number of second through holes (17) are opened on the gas-liquid mixing chamber (6).

5. The aeration system for sewage treatment according to claim 2, characterized in that, The lower end of the gas-liquid mixing chamber (6) is fixedly connected to a flow collector cover (11) through a diameter-changing unit, and the lower end of the flow collector cover (11) is located below the impeller (9).

6. The aeration system for sewage treatment according to claim 5, wherein, A dissolved oxygen sensor (7) is installed inside the flow collector cover (11) or the diameter-changing unit. The dissolved oxygen sensor (7) is used to monitor the DO value of the liquid discharged from the gas-liquid mixing chamber (6).

7. The aeration system for sewage treatment according to claim 6, characterized in that, It also includes a control unit (14), and the control unit (14) is respectively connected to the dissolved oxygen sensor (7), the adjustment motor (20), the submersible motor (5), and the gas flow rate control module (13).

8. The aeration system for sewage treatment according to claim 1, wherein The aeration system also includes an installation unit (1). One end of the installation unit (1) is fixedly connected to the installation cylinder (2), and the other end of the installation unit (1) is used to connect to the outside.

9. An aeration method for sewage treatment, characterized in that, Using the aeration system for sewage treatment described in claim 8, it includes the following steps: Step S1: The adjustment motor adjusts the flow collector cover to the lowest height state, and the control unit obtains the monitoring data of the dissolved oxygen sensor and the gas flow rate control module. Step S2: Input a preset DO value into the control unit. Step S3: The control unit calculates the input value of the gas flow rate control module using proportional integral derivative according to the preset DO value and the actual monitoring value, and sends a signal to the gas flow rate control module for regulation, and monitors the change rate of the DO value within a time window. Step S4: The control unit obtains the data of the adjustment motor. When the flow collector cover is in the highest height state, jump to step S6, otherwise jump to step S5. Step S5: Adjust the adjustment motor with a step size of a to increase the height of the flow collector cover, and jump to step S3 after each adjustment. Step S6: Select the data of the adjustment motor corresponding to the maximum change rate of the DO value as the working data.

10. The aeration method for sewage treatment according to claim 9, characterized in that, In step S3, the proportional integral derivative control law is: Among them, is the control output, i.e., the gas flow rate value of the gas volume regulation module; is the proportional gain; is the integral time constant; is the derivative time constant; is the error signal, i.e., the difference signal between the preset DO value and the actual monitored value.

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