A system and method for capturing phosphorus in sewage

Abstract

The present application relates to sewage treatment technical field, especially to a kind of system for capturing carbon phosphorus in sewage, it includes sequencing batch reactor and reactor accessory system;The sequencing batch reactor includes reactor pool body and is arranged in the water distribution unit of water inlet, sludge unit, aeration unit, decanting unit and dosing distribution unit in the reactor pool body;The reactor accessory system includes water inlet assembly, sludge assembly, aeration assembly, drainage assembly and drug supply assembly, the water inlet assembly is communicated with the water distribution unit, the sludge assembly is communicated with the sludge unit, the aeration assembly is communicated with the aeration unit, the drainage assembly is communicated with the decanting unit, the drug supply assembly is communicated with the dosing distribution unit.Simultaneously, a kind of method for capturing carbon phosphorus in sewage is also provided.Compared with prior art, the system and method for capturing carbon phosphorus in sewage of the present application can improve the capture degree of carbon and phosphorus, and can reduce cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a system and method for capturing carbon and phosphorus in wastewater. Background Technology

[0002] Domestic sewage is characterized by large volumes and high levels of carbon, nitrogen, and phosphorus, presenting significant potential for resource and energy recovery. Currently, nitrogen recovery is not economically viable, while carbon and phosphorus recovery are technologically mature and strategically urgent, respectively. However, the low concentrations of carbon and phosphorus in domestic sewage make direct recovery unsuitable, typically requiring pre-capture and concentration.

[0003] Existing carbon and phosphorus capture and concentration technologies mainly include high-load activated sludge processes, chemically enhanced primary treatment technologies, membrane separation technologies, and combinations thereof. High-load activated sludge processes suffer from low phosphorus capture rates due to their extremely short sludge age, making it difficult for polyphosphate-accumulating bacteria to survive. Furthermore, high-load activated sludge processes are insufficient in capturing colloidal carbon sources. Chemically enhanced primary treatment technologies can effectively capture phosphorus through chemical precipitation, but their effectiveness in capturing dissolved carbon sources is poor, and they consume large amounts of chemicals. While membrane separation technology has continued to develop, problems such as high energy consumption and poor operational stability caused by membrane fouling have not been fundamentally solved. Moreover, as a solid-liquid separation method, membrane separation, when used alone, can only retain colloidal and particulate carbon sources, with minimal effect on capturing dissolved carbon sources and most phosphorus (existing in the form of dissolved orthophosphate). Therefore, coupling high-load activated sludge processes with chemically enhanced primary treatment technologies as a reaction process (i.e., chemical-biological flocculation), and then using gravity sedimentation as the solid-liquid separation process, is a potential technological combination for achieving simultaneous capture of carbon and phosphorus in wastewater.

[0004] CN118324281A discloses a biochemically coupled wastewater carbon capture device and method, which treats wastewater by combining chemical coagulation with activated sludge. However, this scheme involves multiple structures such as a primary reaction tank, a coupled reaction tank, a sludge regeneration tank, and a sedimentation tank, resulting in numerous pieces of equipment and high infrastructure costs. Furthermore, in this scheme, only a portion of the wastewater reacts with the activated sludge under aerobic conditions, limiting the extent to which the activated sludge absorbs dissolved carbon sources and transforms cellular material.

[0005] Chemical-biological flocculation reactors can be classified into continuous stirred reactors (CSTRs) and sequencing batch reactors (SBRs). CSTRs are more widely used, allowing for continuous influent and effluent flow and are easy to operate and maintain. However, they require separate reaction and sedimentation tanks, resulting in high land area and construction costs. Furthermore, in CSTRs, it is difficult to precisely control aeration to achieve a balance between carbon source capture, carbon source oxidation, and effluent quality. SBRs effectively overcome these limitations: firstly, the reaction and sedimentation stages occur in the same space, eliminating the need for separate sedimentation tanks and sludge return systems, saving land area and investment; secondly, the changing trends of various state variables during the reaction stage accurately reflect the reaction progress, thus enabling precise control of aeration duration to maximize carbon source capture while avoiding excessive carbon source oxidation.

[0006] In summary, the development of a chemical-biological flocculation sequencing batch reactor and its method with aeration duration control function is of great significance for achieving efficient and simultaneous capture and further resource utilization of carbon and phosphorus in domestic sewage. Summary of the Invention

[0007] To address the problems of numerous structures, high costs, and limited dissolved organic matter capture in existing wastewater treatment technologies that combine biological and chemical methods, this invention provides a system for capturing carbon and phosphorus in wastewater. This system employs a combination of chemical-biological flocculation and a sequencing batch reactor (SBR) to sequentially complete the influent, aeration, sedimentation, drainage, and sludge removal stages within a single reactor, significantly reducing the number of structures and auxiliary equipment, and lowering infrastructure costs. Furthermore, in each cycle, all influent and activated sludge undergo complete aeration, resulting in a significantly improved capture rate of dissolved organic matter in the influent.

[0008] A system for capturing carbon and phosphorus from wastewater, comprising a sequencing batch reactor and reactor auxiliary systems; The sequencing batch reactor includes a reactor tank and an inlet water distribution unit, a sludge discharge unit, an aeration unit, a decanting unit, and a chemical dosing unit disposed within the reactor tank. The reactor auxiliary system includes an inlet water assembly, a sludge discharge assembly, an aeration assembly, a drainage assembly, and a chemical supply assembly. The inlet water assembly is connected to the inlet water distribution unit, the sludge discharge assembly is connected to the sludge discharge unit, the aeration assembly is connected to the aeration unit, the drainage assembly is connected to the decanting unit, and the chemical supply assembly is connected to the chemical dosing and distribution unit.

[0009] Preferably, it also includes a control system, which is electrically connected to the sequencing batch reactor and the reactor auxiliary system respectively, and is used to control the operation of the equipment in the sequencing batch reactor and the reactor auxiliary system.

[0010] Preferably, the reactor tank is further provided with a stirrer, which is electrically connected to the control system.

[0011] Preferably, the reactor tank is further equipped with a liquid level sensor, a sludge level sensor, a dissolved oxygen sensor, a pH sensor, and a temperature sensor that are electrically connected to the control system.

[0012] Preferably, the water inlet assembly includes a water inlet pump and a water inlet flow sensor. The water inlet pump is connected to the water inlet distribution unit through a pipe, and the water inlet flow sensor is installed on the pipe connecting the water inlet pump and the water inlet distribution unit. The sludge removal assembly includes a sludge removal pump, which is connected to the sludge removal unit via a pipeline; The aeration assembly includes a blower, a blower venting electric valve, and an air volume sensor. The blower is connected to the aeration unit via a pipe, and the blower venting electric valve and the air volume sensor are installed on the pipe connecting the blower and the aeration unit. The drainage assembly includes a drainage pipe, which is connected to the decanting unit; The drug supply assembly includes a dosing pump and a dosing flow sensor. The dosing pump is connected to the dosing distribution unit via a pipeline, and the dosing flow sensor is installed on the pipeline connecting the dosing pump and the dosing distribution unit.

[0013] Preferably, the reactor auxiliary system further includes an overflow prevention component, which includes an overflow prevention pipe and an overflow prevention electric valve. The overflow prevention pipe is connected to the interior of the reactor tank, and the overflow prevention electric valve is installed on the overflow prevention pipe.

[0014] A method for capturing carbon and phosphorus in wastewater, employing a system for capturing carbon and phosphorus in wastewater as described in any of the above-mentioned methods, the method comprising the following steps: S1, Inlet and Drainage Stage: The wastewater to be treated is sent into the reactor tank; S2, Sludge Discharge Stage: The sludge settled in the reactor tank is discharged to the sludge thickening tank; S4, Aeration stage: Air is introduced into the reactor tank; and chemicals are introduced into the reactor tank. S5, Sedimentation stage.

[0015] Preferably, the process between step S2 and step S4 further includes: S3, Overflow Prevention Stage: The overflow prevention component returns the supernatant in the reactor tank to the equalization tank.

[0016] Preferably, step S3, the overflow prevention stage, specifically includes the following steps: S301: Confirm that the sludge discharge stage is over and that the equipment in the reactor auxiliary system is in the off state; S302: Open the anti-overflow electric valve. The anti-overflow stage begins. The supernatant in the reactor tank flows back to the regulating tank by gravity, causing the liquid level in the reactor tank to decrease. S303: Wait for the supernatant level to drop to H LQD,FNL When necessary, close the anti-overflow electric valve; H LQD,FNL The following calculation formula is satisfied:

[0017] in: H LQD,FNL —The overflow prevention electric valve is adjusted by the supernatant level height when it is open or closed, in meters; ΔH PV —Protection height, ranging from [0.05, 0.1], m; H LQD,MAX —Height of the decanting unit weir, in meters; S304: The duration of the overflow prevention phase reaches t. FOF,PV At this point, the overflow prevention phase ends.

[0018] Preferably, step S4, the aeration stage, specifically includes the following steps: S401: Confirm that the overflow prevention stage is over and confirm that the equipment in the reactor auxiliary system is in the off state; S402: Turn on the blower and dosing pump to start the aeration stage. The blower blows air into the reactor tank. The blown air mixes the sludge and sewage. The microorganisms in the sludge use oxygen to convert the dissolved biodegradable organic matter in the sewage and flocculate the colloidal and particulate organic matter in the sewage. The dosing pump pumps the coagulant into the reactor tank. The pumped coagulant reacts with soluble orthophosphate to form metal phosphate precipitates, as well as flocculated gel-like and particulate organic matter. S403: The dosage pump is ready to deliver V. CHME,PV When necessary, turn off the dosing pump; S404: When the external oxygen utilization rate OUR meets the following conditions: Turn off the blower and open the blower's vent valve to stop the blower from supplying air. in: t AIR —The current aeration phase has been in progress, in minutes; t AIR,MIN —Minimum duration setting for the aeration phase; OUR—Exogenous oxygen utilization rate, mg O2·L -1·min -1 ; OUR PV —Exogenous OUR determination value, ranging from [1, 5], mg O2 (L·min) -1 ; t CT,PV —The duration for which the external OUR satisfies the condition, with a value range of [3, 10], min; t AIR,PV —Aeration phase duration setting, in min; S405: The running time during the aeration stage reaches t AIR,PV At this point, the aeration phase ends.

[0019] Preferred, V CHEM,PV The following calculation formula is satisfied:

[0020] in: V CHEM,PV —Set value for coagulant dosage, L; 10—Minimum dosage of coagulant, calculated as coagulant metal element, mg·L -1 ; max() — function to find the maximum value; f MP —Phosphorus ratio of metallic elements, mg·mg -1 P; S PO4,INF —Influent orthophosphate concentration, mg P·L -1 ; S M — Coagulant concentration, expressed as coagulant metal element, g·L -1 ; V INF —Inlet volume during the inlet and outlet stages, in m³ 3 .

[0021] Preferably, the exogenous oxygen utilization rate OUR satisfies the following calculation formula:

[0022] in: OUR—Exogenous oxygen utilization rate, mg O2·L -1 ·min -1 ; K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; SO2 —Dissolved oxygen concentration, mg O2·L -1 ; dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Dissolved oxygen change rate dS O2 The / dt estimation satisfies the following calculation formula:

[0023] in: dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Δt—Estimation step size, min; S O2 —Dissolved oxygen concentration, mg O2·L -1 .

[0024] Preferably, it also includes a correction process: after the sequencing batch reactor has run for several cycles, the oxygen transfer coefficient K is adjusted. La With approximately saturated dissolved oxygen concentration S O2,SAT Perform correction; During the calibration process, the following steps are performed after step S403: SI404: When the aeration time reaches the set value of n aeration stages, the exogenous respiration of microorganisms is fully ended, the dissolved oxygen tends to stabilize, the blower is turned off, the blower vent valve is opened, and the agitator is turned on. Approximate saturated dissolved oxygen concentration S O2,SAT The following calculation formula is satisfied:

[0025] in: S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; n S —Dissolved oxygen concentration data before the blower is turned off; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; t AIR,CAL —The duration of n regular aeration stages, in min; i — the cumulative variable; Δt — Dissolved oxygen concentration recording step size, min; SI405: Microbial endogenous respiration reduces dissolved oxygen. Once the dissolved oxygen concentration drops below 0.5 mg / L, turn off the stirrer. Oxygen transfer coefficient K La The following calculation formula is satisfied:

[0026] in: K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; d SO2 / dt — Rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; n K —Dissolved oxygen concentration data before the stirrer is turned off; i — the cumulative variable; t CAL_FNL —The moment the mixer is turned off; Δt — Dissolved oxygen concentration recording step size, min; SI406: Calibration phase ends.

[0027] Preferably, step S1, the water inlet and drainage stage, specifically includes the following steps: S101: Confirm that the equipment in the reactor auxiliary system is in the off state; S102: Start the inlet pump and the inlet and outlet stage begins. The inlet pump pumps the sewage to be treated from the equalization tank into the reactor tank. In the reactor tank, the sewage flows from bottom to top, pushing the supernatant of the sediment to the decanting unit and finally leaving the reactor tank. The particulate organic matter and phosphorus in the sewage are intercepted by the sedimented sludge layer in the reactor tank. S103: The waiting time for the water inlet and outlet phase reaches t INF,SET At this time, the water inlet pump is shut off, and the water inlet and drainage phases end.

[0028] Preferably, step S2, the sludge removal stage, specifically includes the following steps: S201: Confirm the end of the influent and effluent discharge phases, confirm that the equipment in the reactor auxiliary systems is in the off state, and record the height H of the settled sludge layer in the reactor tank. SLG,INIT ; S202: Start the sludge discharge pump. The sludge discharge stage begins. The sludge discharge pump discharges the sludge settled in the reactor tank to the sludge thickening tank. S203: Wait for the sludge layer height to drop to H SLG,FNL When necessary, shut off the sludge pump; S204: The running time during the sludge discharge stage reaches t. WST,PV At this point, the sludge removal stage ends.

[0029] Preferably, step S5, the precipitation stage, specifically includes the following steps: S501: Confirm that the aeration stage is over, confirm that the equipment in the reactor auxiliary system is in the off state, and open the blower vent valve. S502: Sedimentation stage begins; S503: The running time during the settling stage reaches t. STL,PV The sedimentation stage has ended; After step S5 is completed, the next cycle begins, repeating steps S1 to S5.

[0030] Compared with existing technologies, the system for capturing carbon and phosphorus in wastewater provided by this invention employs a sequencing batch reactor (SBR) and is equipped with a dosing and distribution unit and a dosing assembly. It combines chemical-biological flocculation with the SBR, sequentially completing the stages of influent, aeration, sedimentation, drainage, and sludge removal within a single reactor. This significantly reduces the number of structures and auxiliary equipment, lowering infrastructure costs. Furthermore, by treating wastewater through the SBR, each stage can be carried out in the same space, ensuring that all influent and activated sludge undergo the aeration stage completely in each cycle, thus significantly improving the capture rate of dissolved organic matter in the influent. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic diagram of a system for capturing carbon and phosphorus in wastewater according to one embodiment; Figure 2 This is a schematic flowchart of a method for capturing carbon and phosphorus in wastewater according to one embodiment. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that when a component is referred to as "mounted on", "fixed on", or "set on" another component, it can be directly on or indirectly set on another component; when a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to another component.

[0035] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0036] This invention provides a system for capturing carbon and phosphorus in wastewater, comprising a sequencing batch reactor (SBR) and auxiliary systems. The SBR includes a reactor tank and influent distribution unit, sludge removal unit, aeration unit, decanting unit, and chemical dosing unit disposed within the reactor tank. The auxiliary systems include an influent assembly, sludge removal assembly, aeration assembly, drainage assembly, and chemical supply assembly. The influent assembly is connected to the influent distribution unit, the sludge removal assembly is connected to the sludge removal unit, the aeration assembly is connected to the aeration unit, the drainage assembly is connected to the decanting unit, and the chemical supply assembly is connected to the chemical dosing unit. This system for capturing carbon and phosphorus in wastewater employs a SBR and includes a chemical dosing unit and a chemical supply assembly. It combines chemical-biological flocculation with a SBR, sequentially completing the influent, aeration, sedimentation, drainage, and sludge removal stages within a single reactor, significantly reducing the number of structures and auxiliary equipment and lowering infrastructure costs. Meanwhile, the system treats wastewater using a sequencing batch reactor, with each stage taking place in the same space. In each cycle, all influent and activated sludge undergo the aeration stage completely, significantly improving the capture rate of dissolved organic matter in the influent.

[0037] Please refer to the following: Figure 1 and Figure 2In one embodiment, a system 100 for capturing carbon and phosphorus in wastewater is provided, which adopts a technical approach combining chemical-biological flocculation and sequencing batch reactor. Specifically, it is a sequencing batch reactor system that utilizes chemical-biological flocculation to simultaneously capture carbon and phosphorus in wastewater.

[0038] The system 100 for capturing carbon and phosphorus in wastewater includes a sequencing batch reactor 10 and a reactor auxiliary system 20. The sequencing batch reactor 10 refers to a reactor in which all treatment steps (influent, reaction, sedimentation, drainage, etc.) are carried out in the same reactor tank in chronological order. The reactor auxiliary system 20 refers to an auxiliary system used to cooperate with the reactor in carrying out corresponding work (e.g., fluent, reaction, aeration, drainage, etc.).

[0039] The sequencing batch reactor 10 includes a reactor tank 11 and an inlet water distribution unit 12, a sludge removal unit 13, an aeration unit 14, a decanting unit 15, and a chemical dosing unit 16 disposed within the reactor tank 11. The reactor auxiliary system 20 includes an inlet water assembly 21, a sludge removal assembly 22, an aeration assembly 23, a drainage assembly 24, and a chemical supply assembly 25. The inlet water assembly 21 is connected to the inlet water distribution unit 12 and is used to feed the wastewater to be treated into the reactor tank 11. The sludge removal assembly 22 is connected to the sludge removal unit 13 and is used to discharge the sludge from the reactor tank 11. The aeration assembly 23 is connected to the aeration unit 14 and is used to introduce air into the reactor tank 11. The drainage assembly 24 is connected to the decanting unit 15 and is used to discharge the supernatant from the upper layer of the reactor tank 11. The drug supply component 25 is connected to the drug distribution unit 16 and is used to deliver the drug into the reaction tank 11.

[0040] The system 100 for capturing carbon and phosphorus in wastewater integrates the influent distribution unit 12, the sludge removal unit 13, the aeration unit 14, the decanting unit 15, and the chemical dosing and distribution unit 16 within the reactor tank 11. Employing the sequencing batch reactor 10, the influent, reaction, sedimentation, and drainage stages can be completed within a single reactor tank 11, saving on the number of structures and auxiliary equipment and reducing infrastructure costs. During wastewater treatment, chemical flocculation and biological flocculation can occur simultaneously during the aeration stage of the sequencing batch reactor 10, maximizing the combined and synchronous capture of carbon and phosphorus. Furthermore, since all influent and activated sludge undergo complete aeration in each cycle of the sequencing batch reactor 10, the capture rate of dissolved organic matter in the influent is significantly improved.

[0041] Specifically, the water inlet distribution unit 12, the sludge discharge unit 13, and the aeration unit 14 are located in the bottom area of ​​the reactor tank 11, while the decanting unit 14 and the chemical dosing distribution unit 16 are located in the top area of ​​the reactor tank 11.

[0042] Preferably, in one embodiment, the system 100 for capturing carbon and phosphorus in wastewater further includes a control system 30, which is electrically connected to both the sequencing batch reactor 10 and the reactor auxiliary system 20, and is used to control the operation of the equipment in the sequencing batch reactor 10 and the reactor auxiliary system 20. Controlling the equipment in the sequencing batch reactor 10 and the reactor auxiliary system 20 through the control system 30 allows for more accurate and rapid control of the time of each stage, improving wastewater treatment efficiency.

[0043] Preferably, in one embodiment, a stirrer 17 is further provided inside the reactor tank 11, and the stirrer 17 is electrically connected to the control system 30. The stirrer 17 ensures that the wastewater in the reactor tank 11 remains in a uniform suspended state, promoting thorough mixing of activated sludge and wastewater, ensuring uniform reaction, and maintaining the active state of the sludge during stage transitions.

[0044] Preferably, in one embodiment, the reactor tank 11 is further equipped with a liquid level sensor 101, a sludge level sensor 102, a dissolved oxygen sensor 103, a pH sensor 104, and a temperature sensor 105, all electrically connected to the control system 30. By installing these sensors within the reactor tank 11, the control system 30 can control the corresponding equipment based on the detection signals from each sensor, further improving the wastewater treatment effect.

[0045] Preferably, in one embodiment, the water inlet assembly 21 includes a water inlet pump 211 and a water inlet flow sensor 212. The water inlet pump 211 is connected to the water inlet distribution unit 12 via a pipe, and the water inlet flow sensor 212 is installed on the pipe connecting the water inlet pump 211 and the water inlet distribution unit 12. By installing the water inlet flow sensor 212, the amount of water entering the reactor tank 11 from the water inlet assembly 21 can be fed back in real time, which is beneficial for accurately controlling the amount of wastewater entering the reactor. More preferably, in one embodiment, the water inlet pump 211 and the water inlet flow sensor 212 are electrically connected to the control system 30, so that the control system 30 can receive the detection signal from the water inlet flow sensor 212 and can control the water inlet pump 211.

[0046] Preferably, in one embodiment, the sludge discharge assembly 22 includes a sludge discharge pump 221, which is connected to the sludge discharge unit 13 via a pipeline. When sludge discharge is required, the sludge discharge pump 221 is controlled to operate, thereby discharging the sludge from the reactor tank 11 through the pipeline. More preferably, in one embodiment, the sludge discharge pump 221 is electrically connected to the control system 30, so that the sludge discharge pump 221 can be controlled by the control system 30.

[0047] Preferably, in one embodiment, the aeration assembly 23 includes a blower 231, a blower venting electric valve 232, and an airflow sensor 233. The blower 231 is connected to the aeration unit 14 via a pipe, and the blower venting electric valve 232 and the airflow sensor 233 are installed on the pipe connecting the blower 231 and the aeration unit 14. When aeration is required, the blower 231 is controlled to operate, thereby supplying air to the reactor tank 11 through the pipe. The airflow sensor 233 provides real-time feedback on the air intake of the aeration assembly 23 into the reactor tank 11, facilitating precise control of the aeration stage. More preferably, in one embodiment, the blower 231, the blower venting electric valve 232, and the air volume sensor 233 are electrically connected to the control system 30, so that the control system 30 can receive the detection signal of the air volume sensor 233, and the control system 30 can control the blower 231 and the blower venting electric valve 232.

[0048] Preferably, in one embodiment, the drainage assembly 24 includes a drainage pipe 241 that is connected to the decanting unit 15.

[0049] Preferably, in one embodiment, the drug supply assembly 25 includes a dosing pump 251 and a dosing flow sensor 252. The dosing pump 251 is connected to the dosing distribution unit 16 via a pipeline, and the dosing flow sensor 252 is installed on the pipeline connecting the dosing pump 251 and the dosing distribution unit 16. When drug supply is required, the dosing pump 251 is controlled to operate, thereby delivering the drug into the reactor tank 11 through the pipeline. The dosing flow sensor 252 provides real-time feedback on the amount of drug supplied by the drug supply assembly 25 to the reactor tank 11, facilitating precise dosing control. More preferably, in one embodiment, the dosing pump 251 and the dosing flow sensor 252 are electrically connected to the control system 30, so that the control system 30 can receive the detection signal from the dosing flow sensor 252 and control the dosing pump 251.

[0050] Preferably, in one embodiment, the reactor auxiliary system 20 further includes an overflow prevention component 26, which includes an overflow prevention pipe 261 and an overflow prevention electric valve 262. The overflow prevention pipe 261 communicates with the interior of the reactor tank 11, and the overflow prevention electric valve 262 is disposed on the overflow prevention pipe 261. The overflow prevention component 26 is mainly used to lower the liquid level in the reactor tank 11, preventing the mixed liquor during the aeration stage from flowing into the decanting unit 15, thereby causing a deterioration in effluent quality and a reduction in carbon and phosphorus capture rate. Specifically, the connection point between the overflow prevention pipe 261 and the reactor tank 11 is close to the decanting unit 15, and the connection height is lower than that of the decanting unit 15. More preferably, in one embodiment, the overflow prevention electric valve 262 is electrically connected to the control system 30, so that the control system 30 can control the overflow prevention electric valve 262.

[0051] Specifically, in one embodiment, the decanting unit 15 is a fixed decanter.

[0052] Specifically, in one embodiment, the control system 30 includes hardware and software. The hardware may include a cabinet, a human-machine interface, a programmable logic controller (PLC), digital input modules, digital output modules, analog input modules, analog output modules, and a communication module. The software may include a human-machine interface program and a PLC program. The PLC program may include alarm processing subroutines, input / output processing subroutines, communication processing subroutines, batch process subroutines, oxygen utilization rate calculation subroutines, chemical dosage calculation subroutines, parameter correction batch process subroutines, parameter estimation calculation subroutines, and database subroutines.

[0053] Meanwhile, in one embodiment, a method for capturing carbon and phosphorus in wastewater is also provided, which applies the system 100 for capturing carbon and phosphorus in wastewater. The method for capturing carbon and phosphorus in wastewater is based on the periodic operation of the system 100 for capturing carbon and phosphorus in wastewater, and includes the following steps in sequence: water inlet and drainage stage, sludge discharge stage, overflow prevention stage, aeration stage, and sedimentation stage.

[0054] Specifically, the method for capturing carbon and phosphorus in wastewater includes the following steps: S1, Inlet and Drainage Stage: The wastewater to be treated is sent into the reactor tank; S2, Sludge Discharge Stage: The sludge settled in the reactor tank is discharged to the sludge thickening tank; S4, Aeration stage: Air is introduced into the reactor tank; and chemicals are introduced into the reactor tank. S5, Sedimentation stage.

[0055] The method for capturing carbon and phosphorus in wastewater employs a combination of chemical-biological flocculation and a sequencing batch reactor (SBR). The process sequentially completes the influent, aeration, sedimentation, drainage, and sludge removal stages within a single reactor, significantly reducing the number of structures and auxiliary equipment, and lowering infrastructure costs. Furthermore, by using a SBR to treat wastewater, each stage can be carried out in the same space, ensuring that all influent and activated sludge undergo the aeration stage completely in each cycle, thus significantly improving the capture rate of dissolved organic matter in the influent.

[0056] Preferably, in one embodiment, the process between step S2 and step S4 further includes: S3, an overflow prevention stage: the overflow prevention component returns the supernatant in the reactor tank to the equalization tank. This overflow prevention stage lowers the liquid level in the reactor tank, preventing the mixed liquor from flowing into the decanting unit during subsequent aeration stages, thus avoiding a deterioration in effluent quality and a reduction in carbon and phosphorus capture rate.

[0057] More preferably, in one embodiment, step S3, the overflow prevention stage, specifically includes the following steps: S301: Confirm the end of the sludge discharge stage and confirm that the equipment in the reactor auxiliary system is in the off state; specifically, in this step, confirm that the water inlet pump, sludge discharge pump, agitator, blower, and blower venting electric valve are all in the off state.

[0058] S302: Open the anti-overflow electric valve to start the anti-overflow stage. The supernatant in the reactor tank flows back to the regulating tank by gravity, which lowers the liquid level in the reactor tank. Specifically, in this step, the supernatant in the reactor tank flows back to the regulating tank by gravity through the anti-overflow electric valve and the anti-overflow pipe.

[0059] S303: Wait for the supernatant level to drop to H LQD,FNL When necessary, close the anti-overflow electric valve; H LQD,FNL The following calculation formula is satisfied:

[0060] in: H LQD,FNL —The overflow prevention electric valve is adjusted by the supernatant level height when it is open or closed, in meters; ΔH PV —Protection height, ranging from [0.05, 0.1], m; H LQD,MAX —Height of the decanting unit weir, in meters; S304: The duration of the overflow prevention phase reaches t. FOF,PV At that time, the overflow prevention phase ends. Preferably, in one embodiment, ΔH PV The value is 0.05m, H LQD,MAXThe value is 4m.

[0061] Preferably, in one embodiment, t FOF,PV The value is 5min.

[0062] Preferably, in one embodiment, step S4, the aeration stage, specifically includes the following steps: S401: Confirm the end of the overflow prevention stage and confirm that the equipment in the reactor auxiliary system is in the off state; specifically, in this step, confirm that the water inlet pump, sludge pump, agitator, blower vent electric valve, and overflow prevention electric valve are all in the off state.

[0063] S402: Start the blower and dosing pump to begin the aeration stage. The blower pumps air into the reactor tank, mixing the sludge and wastewater. Microorganisms in the sludge utilize oxygen to convert dissolved biodegradable organic matter in the wastewater and flocculate colloidal and particulate organic matter. Specifically, in this step, the blower pumps air into the reactor tank via an airflow sensor and aeration unit. The control system can adjust the airflow based on the set airflow value Q. AIR,PV Air volume feedback value Q AIR Adjust the blower frequency f AIR This ensures that the airflow remains stable at Q. AIR,PV .

[0064] The dosing pump pumps the coagulant into the reactor tank. The pumped coagulant reacts with soluble orthophosphate to form metal phosphate precipitates, and also flocculates gel-like and particulate organic matter. This step enhances sludge settling performance and significantly improves carbon and phosphorus capture efficiency. Specifically, in this step, the dosing pump pumps the coagulant from the storage tank through a dosing flow sensor and a dosing distribution unit into the reactor tank.

[0065] S403: The dosage pump is ready to deliver V. CHME,PV When necessary, turn off the dosing pump; S404: When the external oxygen utilization rate OUR meets the following conditions:

[0066] Turn off the blower and open the blower's vent valve to stop the blower from supplying air. This step prevents excessive oxidation of the carbon source, which can lead to low carbon capture rate and high energy consumption. The blower's vent valve releases pressure in the aeration pipeline, preventing residual air from escaping from the aeration unit during the subsequent sedimentation stage and affecting the sedimentation effect.

[0067] in: t AIR —The current aeration phase has been in progress, in minutes; t AIR,MIN —Minimum duration setting for the aeration phase; OUR—Exogenous oxygen utilization rate, mg O2·L -1 ·min -1 ; OUR PV —Exogenous OUR determination value, ranging from [1, 5], mg O2 (L·min) -1 ; t CT,PV —The duration for which the external OUR satisfies the condition, with a value range of [3, 10], min; t AIR,PV —Aeration phase duration setting, in min; S405: The running time during the aeration stage reaches t AIR,PV At this point, the aeration phase ends.

[0068] It is understandable that the blower's shutdown time during the aeration phase may vary dynamically, and the actual blower operating time may be shorter than its maximum operating time. However, by extending the aeration phase operating time to t... AIR,PV By stopping the aeration phase at a certain time, the duration of each phase can be fixed, making it easier for operators to conduct regular inspections.

[0069] Preferably, in one embodiment, Q AIR,PV The value is 50m 3 / h.

[0070] Preferably, in one embodiment, the coagulant is ferric chloride (CAS No. 7705-08-0).

[0071] Preferably, in one embodiment, t AIR,MIN The value is 5min, OUR PV The value is taken as 1 mg O (L·min). -1 , t CT,PV The value is 3min.

[0072] Preferably, in one embodiment, t AIR,PV The value is 15min.

[0073] Preferably, in one embodiment, V CHEM,PV The following calculation formula is satisfied:

[0074] in: V CHEM,PV —Set value for coagulant dosage, L; 10—Minimum dosage of coagulant, calculated as coagulant metal element, mg·L -1 ; max() — function to find the maximum value; f MP —Phosphorus ratio of metallic elements, mg·mg -1 P; S PO4,INF —Influent orthophosphate concentration, mg P·L -1 ; S M — Coagulant concentration, expressed as coagulant metal element, g·L -1 ; V INF —Inlet volume during the inlet and outlet stages, in m³ 3 .

[0075] Preferably, in one embodiment, f MP The value is 1.5, S M 20 g / L, V INF 4m 3 .

[0076] Preferably, in one embodiment, the exogenous oxygen utilization rate OUR satisfies the following calculation formula:

[0077] in: OUR—Exogenous oxygen utilization rate, mg O2·L -1 ·min -1 ; K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Dissolved oxygen change rate dS O2 The / dt estimation satisfies the following calculation formula:

[0078] in: dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Δt—Estimation step size, min; S O2 —Dissolved oxygen concentration, mg O2·L-1 .

[0079] Preferably, in one embodiment, step S1, the water inlet and drainage stage, specifically includes the following steps: S101: Confirm that the equipment in the reactor auxiliary system is in the off state; specifically, in this step, confirm that the sludge pump, agitator, blower, blower vent valve, and anti-overflow valve are all in the off state. Additionally, when this step is in a cyclic step, it should also include confirming that the sedimentation phase of the previous cycle has ended. S102: The inlet pump is turned on, initiating the inlet and outlet stage. The inlet pump pumps the wastewater to be treated from the equalization tank into the reactor tank. Within the reactor tank, the wastewater flows from bottom to top, pushing the supernatant out to the decanting unit, and finally exits the reactor tank. Particulate organic matter and phosphorus in the wastewater are retained by the sludge layer in the reactor tank. Specifically, in this step, the inlet pump lifts the wastewater to be treated from the equalization tank through the inlet distribution unit to the reactor tank. Within the reactor tank, the wastewater flows from bottom to top in a plunger-like manner, pushing the supernatant out to the decanting unit, and finally exits the reactor tank through the outlet pipe. The control system can adjust the inlet flow rate based on the set value Q. INF,PV Inlet flow rate feedback value Q INF Adjust the inlet pump frequency f INF This ensures that the actual influent flow rate during the influent and drainage stages remains stable at Q. INF,PV .

[0080] S103: The waiting time for the water inlet and outlet phase reaches t INF,SET At this time, the water inlet pump is shut off, and the water inlet and drainage phases end.

[0081] Preferably, in one embodiment, Q INF,PV 16m 3 / h.

[0082] Preferably, in one embodiment, t INF,SET It takes 15 minutes.

[0083] Preferably, in one embodiment, step S2, the sludge removal stage, specifically includes the following steps: S201: Confirm the end of the influent and effluent discharge phases, confirm that the equipment in the reactor auxiliary systems is in the off state, and record the height H of the settled sludge layer in the reactor tank. SLG,INIT Specifically, in this step, it is confirmed that the water inlet pump, agitator, blower, blower venting electric valve, and overflow prevention electric valve are all in the closed state.

[0084] S202: Start the sludge pump. The sludge discharge stage begins. The sludge pump discharges the sludge settled in the reactor tank to the sludge thickening tank through the sludge discharge pipe. S203: Wait for the sludge layer height to drop to H SLG,FNL When necessary, shut off the sludge pump; H SLG,FNL The calculation formula is as follows:

[0085] in: H SLG,FNL —Height of the sludge layer after sludge removal, in meters; SRT—Mud age, d; n C —Number of reactor cycles per day; H SLG,INIT —Recorded height of the sedimented sludge layer, in meters.

[0086] Preferably, in one embodiment, the SRT is 1.0 d. n C Take 16 times.

[0087] S204: The running time during the sludge discharge stage reaches t. WST,PV At this point, the sludge removal stage ends.

[0088] It is understandable that the shut-off time of the sludge pump during the sludge discharge stage may vary dynamically, and the actual operating time of the sludge pump may be shorter than its longest operating time. However, by extending the sludge discharge stage operating time to t... WST,PV If the sludge removal stage is ended at this time, the duration of each stage can be fixed, making it easier for operators to conduct regular inspections.

[0089] Preferably, in one embodiment, t WST,PV Take 5 minutes.

[0090] Preferably, in one embodiment, step S5, the precipitation stage, specifically includes the following steps: S501: Confirm that the aeration stage has ended, confirm that the equipment in the reactor auxiliary system is in the off state, and open the blower venting electric valve; specifically, in this step, confirm that the water inlet pump, sludge pump, agitator, anti-overflow electric valve, and dosing pump are all in the off state, and confirm that the blower venting electric valve is in the open state.

[0091] S502: Sedimentation stage begins; S503: The running time during the settling stage reaches t. STL,PV The sedimentation stage has ended; After step S5 is completed, the next cycle begins, repeating steps S1 to S5.

[0092] Preferably, in one embodiment, t STL,PV Take 40 minutes.

[0093] Understandably, to ensure treatment effectiveness, the oxygen transfer coefficient K... La and near-saturated dissolved oxygen S O2,SAT Periodic calibration is required. Preferably, in one embodiment, the method for capturing carbon and phosphorus in wastewater further includes a calibration process during the cycle: after the sequencing batch reactor has run for several cycles, the oxygen transfer coefficient K is calibrated. La With approximately saturated dissolved oxygen concentration S O2,SAT Perform corrections.

[0094] Preferably, in one embodiment, one cycle of the overall calibration process may include the following steps: Step SI1: Same as step S1; Step SI2: Same as step S2; Step SI3: Same as step S3; Step SI4: Calibration Phase; SI401: Same as S401; SI402: Same as S402; SI403: Same as S403; SI404: When the aeration time reaches the set value of n aeration stages, the exogenous respiration of microorganisms is fully completed, dissolved oxygen tends to stabilize, the blower is turned off, the blower vent valve is opened, and the agitator is turned on; this step is used to estimate the approximate saturated dissolved oxygen concentration S. O2,SAT Approximate saturated dissolved oxygen concentration S O2,SAT The following calculation formula is satisfied:

[0095] in: S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; n S —Dissolved oxygen concentration data before the blower is turned off; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; t AIR,CAL —The duration of n regular aeration stages, in min; i — the cumulative variable; Δt — Dissolved oxygen concentration recording step size, min; Preferably, in one embodiment, n S Take 12, t AIR,CAL Take 75 min, and Δt is 1 / 6 min.

[0096] SI405: Microbial endogenous respiration reduces dissolved oxygen. Once the dissolved oxygen concentration drops below 0.5 mg / L, turn off the stirrer. This step is used to estimate the oxygen transfer coefficient K. La Oxygen transfer coefficient K La The following calculation formula is satisfied:

[0097] in: K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; d SO2 / dt — Rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; n K —Dissolved oxygen concentration data before the stirrer is turned off; i — the cumulative variable; t CAL_FNL —The moment the mixer is turned off; Δt — Dissolved oxygen concentration recording step size, min; Preferably, in one embodiment, n K Take 24, and Δt is 1 / 6 min.

[0098] SI406: Calibration phase ends.

[0099] Step SI5: Sedimentation stage.

[0100] SI501: Confirm that the calibration phase is complete, confirm that the inlet pump, sludge pump, agitator, anti-overflow electric valve, and dosing pump are all in the closed state, and confirm that the blower venting electric valve is in the open state.

[0101] SI502: Precipitation stage begins.

[0102] SI503: The running time during the sedimentation stage reaches t STL,PV The sedimentation stage has ended.

[0103] Preferably, in one embodiment, t STL,PV Take 30 minutes.

[0104] After step SI5 is completed, the regular S1~S5 cycle process begins.

[0105] It is understandable that existing technologies employing biochemical coupling for wastewater treatment (such as CN118324281A) have the following problems: First, the device includes four structures: a primary reaction tank, a coupling reaction tank, a sludge regeneration tank, and a sedimentation tank. The numerous structures and equipment involved result in high infrastructure costs. Second, chemical flocculation and biological flocculation are separated spatially and temporally in the device and method, failing to fully utilize the coupling effect and resulting in low carbon and phosphorus capture rates. Third, only a portion of the wastewater reacts with activated sludge under aerobic conditions, leading to a low degree of activated sludge absorption of dissolved carbon sources and conversion of cellular material. Finally, the method lacks precise process control and adaptability to changes in organic matter and phosphorus load in the influent, making it impossible to achieve an optimal balance between carbon and phosphorus capture, aeration energy consumption, and reagent consumption.

[0106] The system 100 and method for capturing carbon and phosphorus in wastewater provided in this application have the following advantages compared with the prior art: 1. The sequencing batch reactor is adopted, which completes the stages of water intake, reaction, sedimentation and drainage in one reactor, saving the number of structures and auxiliary equipment and reducing infrastructure costs; 2. Chemical flocculation and bioflocculation occur simultaneously during the aeration stage of the sequencing batch reactor, and the combined and synchronous capture of carbon and phosphorus can be fully utilized. 3. In each cycle of the sequencing batch reactor, all the influent and activated sludge completely pass through the aeration stage, which can significantly improve the capture rate of dissolved organic matter in the influent; 4. Feedforward control of coagulant dosage is achieved by monitoring phosphorus concentration in the influent, and the aeration stage duration is controlled in real time by monitoring oxygen utilization rate, so as to achieve the best carbon and phosphorus capture and avoid excessive coagulant dosage or air aeration. 5. Coordinate the decanter and process settings to enable the sequencing batch reactor to have synchronous water intake and drainage capabilities, providing conditions for the combined operation of multiple sequencing batch reactors to achieve the continuous water intake and drainage effect of a continuous flow reactor.

[0107] The following will describe specific embodiments of the system 100 and the method for capturing carbon and phosphorus in wastewater: The example uses blackwater separated from domestic sewage sources. The main water quality parameters are shown in Table 1 below. Blackwater is sewage generated from residential toilets, including urine, feces, and flushing water.

[0108] Table 1 Water quality characteristics

[0109] COD: Chemical Oxygen Demand Using the system 100 for capturing carbon and phosphorus in wastewater, and according to the method for capturing carbon and phosphorus in wastewater (wherein, ΔH PV The value is 0.05m, H LQD,MAX The value is 4m, t FOF,PV The value is 5min, Q AIR,PV The value is 50m 3 / h, the coagulant is ferric chloride (CAS No. 7705-08-0), t AIR,MIN The value is 5min, OUR PV The value is taken as 1 mg O (L·min). -1 , t CT,PV The value is 3min, t AIR,PV The value is 15min, f MP The value is 1.5, S M 20 g / L, V INF 4m 3 Q INF,PV 16m 3 / h,t INF,SET The time is 15 min, and the SRT is 1.0 d. n C Take 16 times, t WST,PV Take 5 minutes, t STL,PV The experiment was conducted over a period of 40 minutes, and the capture rate of carbon source was 74.0% ± 4.7%, while the capture rate of phosphorus was 82.2% ± 1.9%.

[0110] The carbon source capture rates of Examples 1-3 disclosed in CN110510802A are only 25.9%-48.7%, and the phosphorus source capture rates are only 14%-28.7%.

[0111] In another example, the aeration phase duration control in the method for capturing carbon and phosphorus in wastewater was removed using the system 100 for capturing carbon and phosphorus in wastewater. The aeration duration was fixed at 40 minutes. The carbon source capture amount was similar to that of the example (75.2%), but excessive aeration occurred, and the aeration energy consumption was 167% higher than that of the example.

[0112] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A system for capturing carbon and phosphorus in wastewater, characterized in that, Including sequencing batch reactors and reactor auxiliary systems; The sequencing batch reactor includes a reactor tank and an inlet water distribution unit, a sludge discharge unit, an aeration unit, a decanting unit, and a chemical dosing unit disposed within the reactor tank. The reactor auxiliary system includes an inlet water assembly, a sludge discharge assembly, an aeration assembly, a drainage assembly, and a chemical supply assembly. The inlet water assembly is connected to the inlet water distribution unit, the sludge discharge assembly is connected to the sludge discharge unit, the aeration assembly is connected to the aeration unit, the drainage assembly is connected to the decanting unit, and the chemical supply assembly is connected to the chemical dosing and distribution unit.

2. The system for capturing carbon and phosphorus in wastewater according to claim 1, characterized in that, It also includes a control system, which is electrically connected to the sequencing batch reactor and the reactor auxiliary system respectively, and is used to control the operation of the equipment in the sequencing batch reactor and the reactor auxiliary system.

3. The system for capturing carbon and phosphorus in wastewater according to claim 2, characterized in that, The reactor tank is also equipped with a stirrer, which is electrically connected to the control system.

4. The system for capturing carbon and phosphorus in wastewater according to claim 2, characterized in that, The reactor tank is also equipped with a liquid level sensor, a sludge level sensor, a dissolved oxygen sensor, a pH sensor, and a temperature sensor that are electrically connected to the control system.

5. The system for capturing carbon and phosphorus in wastewater according to claim 1, characterized in that, The water inlet assembly includes a water inlet pump and a water inlet flow sensor. The water inlet pump is connected to the water inlet distribution unit through a pipe, and the water inlet flow sensor is installed on the pipe connecting the water inlet pump and the water inlet distribution unit. The sludge removal assembly includes a sludge removal pump, which is connected to the sludge removal unit via a pipeline; The aeration assembly includes a blower, a blower venting electric valve, and an air volume sensor. The blower is connected to the aeration unit via a pipe, and the blower venting electric valve and the air volume sensor are installed on the pipe connecting the blower and the aeration unit. The drainage assembly includes a drainage pipe, which is connected to the decanting unit; The drug supply assembly includes a dosing pump and a dosing flow sensor. The dosing pump is connected to the dosing distribution unit via a pipeline, and the dosing flow sensor is installed on the pipeline connecting the dosing pump and the dosing distribution unit.

6. The system for capturing carbon and phosphorus in wastewater according to claim 1, characterized in that, The reactor auxiliary system also includes an overflow prevention component, which includes an overflow prevention pipe and an overflow prevention electric valve. The overflow prevention pipe is connected to the inside of the reactor tank, and the overflow prevention electric valve is installed on the overflow prevention pipe.

7. A method for capturing carbon and phosphorus in wastewater, characterized in that, The system for capturing carbon and phosphorus in wastewater as described in any one of claims 1 to 6 is used, and the method for capturing carbon and phosphorus in wastewater comprises the following steps: S1, Inlet and Drainage Stage: The wastewater to be treated is sent into the reactor tank; S2, Sludge Discharge Stage: The sludge settled in the reactor tank is discharged to the sludge thickening tank; S4, Aeration stage: Air is introduced into the reactor tank; and chemicals are introduced into the reactor tank. S5, Sedimentation stage.

8. The method for capturing carbon and phosphorus in wastewater according to claim 7, characterized in that, Between step S2 and step S4, the following is also included: S3, Overflow Prevention Stage: The overflow prevention component returns the supernatant in the reactor tank to the equalization tank.

9. The method for capturing carbon and phosphorus in wastewater according to claim 8, characterized in that, Step S3, the overflow prevention stage, specifically includes the following steps: S301: Confirm that the sludge discharge stage is over and that the equipment in the reactor auxiliary system is in the off state; S302: Open the anti-overflow electric valve. The anti-overflow stage begins. The supernatant in the reactor tank flows back to the regulating tank by gravity, causing the liquid level in the reactor tank to decrease. S303: Wait for the supernatant level to drop to H LQD,FNL When necessary, close the anti-overflow electric valve; H LQD,FNL The following calculation formula is satisfied: ； in: H LQD,FNL —The overflow prevention electric valve is adjusted by the supernatant level height when it is open or closed, in meters; ΔH PV —Protection height, ranging from [0.05, 0.1], m; H LQD,MAX —Height of the decanting unit weir, in meters; S304: The duration of the overflow prevention phase reaches t. FOF,PV At this point, the overflow prevention phase ends.

10. The method for capturing carbon and phosphorus in wastewater according to claim 8, characterized in that, Step S4, the aeration stage, specifically includes the following steps: S401: Confirm that the overflow prevention stage is over and confirm that the equipment in the reactor auxiliary system is in the off state; S402: Turn on the blower and dosing pump to start the aeration stage. The blower blows air into the reactor tank. The blown air mixes the sludge and sewage. The microorganisms in the sludge use oxygen to convert the dissolved biodegradable organic matter in the sewage and flocculate the colloidal and particulate organic matter in the sewage. The dosing pump pumps the coagulant into the reactor tank. The pumped coagulant reacts with soluble orthophosphate to form metal phosphate precipitates, as well as flocculated gel-like and particulate organic matter. S403: The dosage pump is ready to deliver V. CHME,PV When necessary, turn off the dosing pump; S404: When the external oxygen utilization rate OUR meets the following conditions: Turn off the blower, open the blower's vent valve, and stop the blower from supplying air. in: t AIR —The current aeration phase has been in progress, in minutes; t AIR,MIN —Minimum duration setting for the aeration phase; OUR—Exogenous oxygen utilization rate, mg O2·L -1 ·min -1 ; OUR PV —Exogenous OUR determination value, ranging from [1, 5], mg O2 (L·min) -1 ; t CT,PV —The duration for which the external OUR satisfies the condition, with a value range of [3, 10], min; t AIR,PV —Aeration phase duration setting, in min; S405: The running time during the aeration stage reaches t AIR,PV At this point, the aeration phase ends.

11. The method for capturing carbon and phosphorus in wastewater according to claim 10, characterized in that, V CHEM,PV The following calculation formula is satisfied: ； in: V CHEM,PV —Set value for coagulant dosage, L; 10—Minimum dosage of coagulant, calculated as coagulant metal element, mg·L -1 ; max() — function to find the maximum value; f MP —Phosphorus ratio of metallic elements, mg·mg -1 P; S PO4,INF —Influent orthophosphate concentration, mg P·L -1 ; S M — Coagulant concentration, expressed as coagulant metal element, g·L -1 ; V INF —Inlet volume during the inlet and outlet stages, in m³ 3 .

12. The method for capturing carbon and phosphorus in wastewater according to claim 10, characterized in that, The exogenous oxygen utilization rate (OUR) satisfies the following calculation formula: ； in: OUR—Exogenous oxygen utilization rate, mg O2·L -1 ·min -1 ; K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Dissolved oxygen change rate dS O2 The / dt estimation satisfies the following calculation formula: ； in: dS O2 / dt—rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; Δt—Estimation step size, min; S O2 —Dissolved oxygen concentration, mg O2·L -1 .

13. The method for capturing carbon and phosphorus in wastewater according to claim 12, characterized in that, It also includes a correction process: after the sequencing batch reactor has run for several cycles, the oxygen transfer coefficient K is adjusted. La With approximately saturated dissolved oxygen concentration S O2,SAT Perform correction; During the calibration process, the following steps are performed after step S403: SI404: When the aeration time reaches the set value of n aeration stages, the exogenous respiration of microorganisms is fully ended, the dissolved oxygen tends to stabilize, the blower is turned off, the blower vent valve is opened, and the agitator is turned on. Approximate saturated dissolved oxygen concentration S O2,SAT The following calculation formula is satisfied: ； in: S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; n S —Dissolved oxygen concentration data before the blower is turned off; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; t AIR,CAL —The duration of n regular aeration stages, in min; i — the cumulative variable; Δt — Dissolved oxygen concentration recording step size, min; SI405: Microbial endogenous respiration reduces dissolved oxygen. Once the dissolved oxygen concentration drops below 0.5 mg / L, turn off the stirrer. Oxygen transfer coefficient K La The following calculation formula is satisfied: ； in: K La —Oxygen transfer coefficient, min -1 ; S O2,SAT —Approximate saturated dissolved oxygen concentration, mg O2·L -1 ; S O2 —Dissolved oxygen concentration, mg O2·L -1 ; d SO2 / dt — Rate of change in dissolved oxygen, mg O2·L -1 ·min -1 ; n K —Dissolved oxygen concentration data before the stirrer is turned off; i — the cumulative variable; t CAL_FNL —The moment the mixer is turned off; Δt — Dissolved oxygen concentration recording step size, min; SI406: Calibration phase ends.

14. The method for capturing carbon and phosphorus in wastewater according to claim 7, characterized in that, Step S1, the water inlet and drainage stage, specifically includes the following steps: S101: Confirm that the equipment in the reactor auxiliary system is in the off state; S102: Start the inlet pump and the inlet and outlet stage begins. The inlet pump pumps the sewage to be treated from the equalization tank into the reactor tank. In the reactor tank, the sewage flows from bottom to top, pushing the supernatant of the sediment to the decanting unit and finally leaving the reactor tank. The particulate organic matter and phosphorus in the sewage are intercepted by the sedimented sludge layer in the reactor tank. S103: The waiting time for the water inlet and outlet phase reaches t INF,SET At this time, the water inlet pump is shut off, and the water inlet and drainage phases end.

15. The method for capturing carbon and phosphorus in wastewater according to claim 7, characterized in that, Step S2, the sludge removal stage, specifically includes the following steps: S201: Confirm the end of the influent and effluent discharge phases, confirm that the equipment in the reactor auxiliary systems is in the off state, and record the height H of the settled sludge layer in the reactor tank. SLG,INIT ; S202: Start the sludge discharge pump. The sludge discharge stage begins. The sludge discharge pump discharges the sludge settled in the reactor tank to the sludge thickening tank. S203: Wait for the sludge layer height to drop to H SLG,FNL When necessary, shut off the sludge pump; S204: The running time during the sludge discharge stage reaches t. WST,PV At this point, the sludge removal stage ends.

16. The method for capturing carbon and phosphorus in wastewater according to claim 7, characterized in that, Step S5, the sedimentation stage, specifically includes the following steps: S501: Confirm that the aeration stage is over, confirm that the equipment in the reactor auxiliary system is in the off state, and open the blower vent valve. S502: Sedimentation stage begins; S503: The running time during the settling stage reaches t STL,PV The sedimentation stage has ended; After step S5 is completed, the next cycle begins, repeating steps S1 to S5.

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