Device and operation method for enhancing simultaneous denitrification and efficient phosphorus removal based on multi-stage a / o process

Abstract

This invention provides an apparatus and operating method for enhanced simultaneous nitrogen and phosphorus removal based on a multi-stage A / O process in the field of municipal wastewater biological treatment. The apparatus includes: an influent device, a multi-stage A / O treatment reactor, a secondary sedimentation tank, and an automatic control system. The influent device is connected to the multi-stage A / O treatment reactor, which is connected to the secondary sedimentation tank. The automatic control system controls the influent device, the multi-stage A / O treatment reactor, and the secondary sedimentation tank, performing data monitoring and adjustment management. Wastewater from the influent device enters the multi-stage A / O treatment reactor for nitrogen and phosphorus removal. The effluent from the multi-stage A / O treatment reactor flows into the secondary sedimentation tank for sludge-water separation. Sludge from the bottom of the secondary sedimentation tank is returned to the multi-stage A / O treatment reactor, and excess sludge from the secondary sedimentation tank is discharged from the system. This invention achieves enrichment of short-cut nitrification / denitrification, aerobic simultaneous nitrogen removal, and highly efficient phosphorus removal bacteria by optimizing the stirring method and controlling the return system, effectively reducing aeration intensity and saving energy.

Description

Technical Field

[0001] This invention relates to the field of biological treatment of municipal wastewater, specifically to an apparatus and operating method for enhanced simultaneous nitrogen removal and efficient phosphorus removal based on a multi-stage A / O process. Background Technology

[0002] With socio-economic development and rising living standards, water pollution has become increasingly prominent. Urban sewage discharge and pollution concentrations are rising daily. The nitrogen and phosphorus in sewage, when discharged into natural water bodies, lead to the proliferation of algae and other pollutants, causing eutrophication and significantly impacting human life and production. Therefore, strengthening the scale and quality of sewage treatment is urgently needed. Simultaneously, global warming is causing frequent heavy rainfall during the rainy season, exacerbating urban runoff pollution and further intensifying overflow pollution, thus posing a significant challenge to urban sewage treatment.

[0003] While nitrogen and phosphorus removal processes have achieved some success in municipal wastewater treatment plants, several shortcomings remain, such as the competition for carbon sources during nitrogen and phosphorus removal, the complexity and precise control of biological processes, and the instability of sludge activity. Traditional nitrification-denitrification nitrogen removal technologies require significant aeration energy and carbon source consumption, resulting in high energy consumption and high carbon emissions; while chemical phosphorus removal requires the addition of chemicals, increasing treatment costs. These chemical and energy consumption factors contribute to the high cost of municipal wastewater treatment, making the search for simple, efficient, and stable treatment processes particularly important.

[0004] Traditional biological treatment technologies are prone to sludge bulking and floating during seasonal temperature fluctuations, primarily due to poor sludge settling properties and excessively high sludge concentration. This results in serious consequences such as reduced treatment efficiency, increased energy consumption, and substandard effluent quality. Wastewater treatment plants need to invest more in equipment upgrades and operation and maintenance; simultaneously, sludge treatment and disposal become more difficult. Therefore, effectively improving the sludge settling performance of biological treatment systems and optimizing sludge concentration are key tasks for ensuring the effective treatment of municipal wastewater. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide a device and operating method for enhancing simultaneous denitrification and efficient phosphorus removal based on a multi-stage A / O process.

[0006] According to the present invention, a device for enhanced simultaneous denitrification and efficient phosphorus removal based on a multi-stage A / O process is provided, comprising: an inlet device, a multi-stage A / O treatment reactor, a secondary sedimentation tank, and an automatic control system. The inlet device is connected to the multi-stage A / O treatment reactor, the multi-stage A / O treatment reactor is connected to the secondary sedimentation tank, and the automatic control system controls the inlet device, the multi-stage A / O treatment reactor, and the secondary sedimentation tank respectively, and performs data monitoring and adjustment management.

[0007] Wastewater from the influent device enters the multi-stage A / O treatment reactor for nitrogen and phosphorus removal. The effluent from the multi-stage A / O treatment reactor flows into the secondary sedimentation tank for sludge-water separation. The sludge at the bottom of the secondary sedimentation tank is returned to the multi-stage A / O treatment reactor, and the remaining sludge in the secondary sedimentation tank is discharged from the system.

[0008] Preferably, the multi-stage A / O treatment reactor includes an anoxic zone and an aerobic zone, with multiple anoxic zones and multiple aerobic zones distributed alternately, and the guide holes of two adjacent anoxic zones and aerobic zones are connected.

[0009] The anoxic zone includes anoxic zone 1, anoxic zone 2, and anoxic zone 3. The aerobic zone includes aerobic zone 1, aerobic zone 2, and aerobic zone 3. Anoxic zone 1, aerobic zone 1, anoxic zone 2, aerobic zone 3, anoxic zone 3, and aerobic zone 3 are connected in sequence. The water inlet device is connected through anoxic zone 1, and the aerobic zone is connected to the secondary sedimentation tank.

[0010] Preferably, each anoxic zone is equipped with a surface agitator, an internal circulation agitator, and an anoxic zone monitor. The internal circulation agitator is located at the lower end of the anoxic zone, the surface agitator is located at the upper end of the anoxic zone, and the anoxic zone monitor is located outside the mixing range of the internal circulation agitator. The sludge in the anoxic zone is evenly mixed by the internal circulation agitator, and the surface agitator inhibits the sludge from floating.

[0011] The anoxic zone 1 is equipped with an anoxic zone 1 liquid surface baffle, an anoxic zone 1 internal circulation agitator, and an anoxic zone 1 monitoring instrument. The anoxic zone 2 is equipped with an anoxic zone 2 liquid surface baffle, an anoxic zone 2 internal circulation agitator, and an anoxic zone 2 monitoring instrument. The anoxic zone 3 is equipped with an anoxic zone 3 liquid surface baffle, an anoxic zone 3 internal circulation agitator, and an anoxic zone 3 monitoring instrument.

[0012] Preferably, each aerobic zone is equipped with an aeration device at the bottom and an aerobic zone monitor at the top. The aeration device is connected to an aeration pump via a rotor flow meter, and the aeration pump is electrically connected to an automatic control system.

[0013] Aerobic Zone 1 is equipped with an aeration device and an aeration monitoring instrument for Aerobic Zone 1; Aerobic Zone 2 is equipped with an aeration device and an aeration monitoring instrument for Aerobic Zone 2; and Aerobic Zone 3 is equipped with an aeration device and an aeration monitoring instrument for Aerobic Zone 3.

[0014] Preferably, the DO in aerobic zone 1 is controlled at 0.3-1 mg / L by a rotor flow meter, the DO in aerobic zone 2 is controlled at 0.5-1.5 mg / L by a rotor flow meter, and the DO in aerobic zone 3 is controlled at 2-4 mg / L by a rotor flow meter.

[0015] Preferably, the secondary sedimentation tank includes a secondary sedimentation tank, a sludge return pump, a secondary sedimentation tank monitoring instrument, and a secondary sedimentation tank backflushing system. The anoxic zone is connected to the secondary sedimentation tank through an overflow pipe. The bottom of the secondary sedimentation tank is connected to the sludge return pump and the secondary sedimentation tank backflushing system, respectively. The secondary sedimentation tank monitoring instrument is installed inside the secondary sedimentation tank and is electrically connected to the automatic control system.

[0016] The secondary sedimentation tank backwashing system is connected to reclaimed water / tap water via a backwash pump. The secondary sedimentation tank is monitored in real time by a secondary sedimentation tank monitoring instrument. The secondary sedimentation tank backwashing system (3.4) adjusts the backwashing intensity and frequency to regulate the flow rate, concentration and pollutant concentration of the returned sludge in the secondary sedimentation tank.

[0017] Preferably, the water inlet device includes a municipal sewage tank and an inlet water pump, with the municipal sewage tank connected to the anoxic zone via the inlet water pump.

[0018] Preferably, the automatic control system includes an automatic electrical distribution box, which controls and connects to the inlet water pump, the surface agitator in the anoxic zone 1, the internal circulation mixer in the anoxic zone 1, the anoxic zone 1 monitor, the aeration device in the aerobic zone 1, the aerobic zone 1 monitor, the surface agitator in the anoxic zone 2, the internal circulation mixer in the anoxic zone 2, the anoxic zone 2 monitor, the aeration device in the aerobic zone 2, the aerobic zone 2 monitor, the surface agitator in the anoxic zone 3, the internal circulation mixer in the anoxic zone 3, the anoxic zone 3 monitor, the aeration device in the aerobic zone 3, the aeration pump, and the aeration pump.

[0019] This invention also provides an operating method for an apparatus for enhanced simultaneous nitrogen removal and efficient phosphorus removal based on a multi-stage A / O process, comprising the following specific operating steps:

[0020] S1. Start the equipment and control the hydraulic retention time, influent ratio and external return ratio of the anoxic zone through the automatic control electrical distribution box;

[0021] S2. Municipal sewage in the municipal sewage tank enters the anoxic zone through the inlet water pump. The sewage and external return sludge in the anoxic zone pass through multiple anoxic zones and multiple aerobic zones in sequence to remove nitrogen and phosphorus.

[0022] S3. The effluent from the aerobic zone flows into the secondary sedimentation tank through the overflow pipe for sludge-water separation. The sludge at the bottom of the secondary sedimentation tank is returned to the anoxic zone through the sludge return pump. The remaining sludge in the secondary sedimentation tank is discharged from the system through the sludge discharge pipe.

[0023] Preferably, the sludge return ratio at the bottom of the secondary sedimentation tank is 80%-150%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) This invention optimizes the sludge activity of the system through backwashing in the secondary sedimentation tank, achieves short-cut nitrification and denitrification in low DO mode, and achieves simultaneous denitrification by rationally allocating carbon sources. The total simultaneous denitrification rate can reach more than 60%.

[0026] (2) The internal circulation stirring and liquid surface disturbance device of the present invention inhibits the floating of sludge in the anoxic zone, while the low DO improves the carbon source utilization of PAOs, realizing efficient phosphorus release and absorption. The TP in the secondary sedimentation tank effluent can be as low as 0.1 mg / L, which greatly saves the cost of phosphorus removal agents.

[0027] (3) The present invention effectively regulates the settling and activity of the sludge in the system by backwashing the secondary sedimentation tank, inhibits sludge floating and expansion, curbs sludge runoff from the secondary sedimentation tank, and effectively reduces the cost of sludge dewatering.

[0028] (4) The operating method in this invention can effectively cope with the severe overflow pollution during the flood season, can operate stably for a week under the super-inflow load (150%), and does not require the addition of carbon source, showing strong system operation stability. Attached Figure Description

[0029] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the connection relationship in this invention.

[0031] The diagram shows: 1.1—Municipal sewage tank; 1.2—Inlet pump; 2.1—Anoxic zone 1; 2.2—Surface agitator in anoxic zone 1; 2.3—Circulating agitator in anoxic zone 1; 2.4—Monitoring device for anoxic zone 1; 2.5—Aerobic zone 1; 2.6—Aeration device in aerobic zone 1; 2.7—Monitoring device for aerobic zone 1; 2.8—Anoxic zone 2; 2.9—Surface agitator in anoxic zone 2; 2.10—Circulating agitator in anoxic zone 2; 2.11—Monitoring device for anoxic zone 2; 2.12—Aerobic zone 2; 2.13—Aerobic zone 2 Aeration device; 2.14—Aerobic Zone 2 monitor; 2.15—Anoxic Zone 3; 2.16—Anoxic Zone 3 surface disturbance device; 2.17—Anoxic Zone 3 internal circulation mixer; 2.18—Anoxic Zone 3 monitor; 2.19—Aerobic Zone 3; 2.20—Aerobic Zone 3 aeration device; 2.21—Aerobic Zone 3 monitor; 2.22—Aeration pump; 3.1—Secondary sedimentation tank; 3.2—Sludge return pump; 3.3—Secondary sedimentation tank monitor; 3.4—Sludge backflushing system; 4—Automatic control system; 4.1—Automatic electrical distribution box. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0033] Example 1

[0034] According to the present invention, a device for enhanced simultaneous denitrification and efficient phosphorus removal based on a multi-stage A / O process is provided, such as... Figure 1 As shown, the system includes: an inlet device 1, a multi-stage A / O treatment reactor 2, a secondary sedimentation tank 3, and an automatic control system 4. The inlet device 1 is connected to the multi-stage A / O treatment reactor 2, and the multi-stage A / O treatment reactor 2 is connected to the secondary sedimentation tank 3. The automatic control system 4 controls the inlet device 1, the multi-stage A / O treatment reactor 2, and the secondary sedimentation tank 3 respectively, and performs data monitoring and adjustment management. The wastewater in the inlet device 1 enters the multi-stage A / O treatment reactor 2 for denitrification and phosphorus removal. The effluent from the multi-stage A / O treatment reactor 2 flows into the secondary sedimentation tank 3 for sludge-water separation. The sludge at the bottom of the secondary sedimentation tank 3 is returned to the multi-stage A / O treatment reactor 2. The remaining sludge in the secondary sedimentation tank 3 is discharged from the system.

[0035] The multi-stage A / O treatment reactor 2 includes anoxic and aerobic zones, with multiple anoxic and aerobic zones spaced apart and connected by flow channels between adjacent anoxic and aerobic zones. The anoxic zone is equipped with a surface agitator, an internal circulation stirrer, and an anoxic zone monitor. The internal circulation stirrer is located at the lower end of the anoxic zone, the surface agitator at the upper end, and the anoxic zone monitor is located outside the stirring range of the internal circulation stirrer. The sludge in the anoxic zone is uniformly stirred by the internal circulation stirrer, and the surface agitator inhibits sludge floating. The aerobic zone has an aeration device at the bottom and an aerobic zone monitor at the upper end. The aeration device is connected to an aeration pump 2.22 via a rotor flow meter, and the aeration pump 2.22 is electrically connected to the automatic control system 4.

[0036] The inlet device 1 includes a municipal sewage tank 1.1 and an inlet pump 1.2. The municipal sewage tank 1.1 is connected to the anoxic zone 2.1 via the inlet pump 1.2. The secondary sedimentation tank 3 includes a secondary sedimentation tank 3.1, a sludge return pump 3.2, a secondary sedimentation tank monitoring instrument 3.3, and a secondary sedimentation tank backwashing system 3.4. The anoxic zone 2.15 is connected to the secondary sedimentation tank 3.1 via an overflow pipe. The bottom of the secondary sedimentation tank 3.1 is connected to the sludge return pump 3.2 and the secondary sedimentation tank backwashing system 3.4. The secondary sedimentation tank monitoring instrument 3.3 is installed inside the secondary sedimentation tank 3.1 and is electrically connected to the automatic control system 4. The secondary sedimentation tank backwashing system 3.4 is connected to reclaimed water / tap water via a backwash pump, and the secondary sedimentation tank backwashing system 3.4 adjusts the backwashing intensity and frequency based on the real-time monitoring of the secondary sedimentation tank 3.1 by the secondary sedimentation tank monitoring instrument 3.3.

[0037] More specifically, the backflushing and internal circulation mixing system of the secondary sedimentation tank is adjusted as follows: The secondary sedimentation tank 3 is monitored in real time using the secondary sedimentation tank monitoring instrument 3.3. The backflushing system 3.4 is activated in real time to regulate the flow rate, concentration, and pollutant concentration of the returned sludge in the secondary sedimentation tank, optimizing the returned sludge concentration and the return activity (NO3). - -N and TP) control the denitrification and phosphorus removal activity of reactor sludge, cultivate dominant bacterial communities, improve sludge settling performance, and effectively inhibit sludge floating; at the same time, the internal circulation stirring in the anoxic zone ensures that the sludge reacts evenly and fully, while the liquid surface baffle inhibits sludge floating and inhibits sludge expansion.

[0038] Municipal wastewater first enters the influent unit 1, then flows into the multi-stage A / O treatment reactor 2 for efficient removal of carbon, nitrogen, and phosphorus through biological treatment. By optimizing the stirring method and controlling the reflux system, short-cut nitrification / denitrification, simultaneous aerobic denitrification, and the enrichment of highly efficient phosphorus-removing bacteria are achieved. Based on the above device, and according to actual operating experience and control methods, the device achieves deep nitrogen and phosphorus removal from municipal wastewater, while simultaneously handling overflow pollution simulating the flood season's excessive influent load. It is suitable for municipal wastewater treatment, integrated biological treatment units, and flood season overflow pollution control in rural areas. It requires no external carbon source or phosphorus removal agents, effectively reduces aeration intensity, and features energy saving and consumption reduction.

[0039] Example 2

[0040] This Example 2 is based on Example 1, and mainly elaborates on the multi-stage A / O treatment reactor 2. Specifically:

[0041] The anoxic zone includes anoxic zone 1 (2.1), anoxic zone 2 (2.8), and anoxic zone 3 (2.15). The aerobic zone includes aerobic zone 1 (2.5), aerobic zone 2 (2.12), and aerobic zone 3 (2.19). Anoxic zone 1 (2.1), aerobic zone 1 (2.5), anoxic zone 2 (2.8), aerobic zone 2 (2.12), anoxic zone 3 (2.15), and aerobic zone 3 (2.19) are connected in sequence. The water inlet device 1 is connected through anoxic zone 1 (2.1) and aerobic zone 3 (2.19) is connected to the secondary sedimentation tank 3.

[0042] Zone 1 (2.1) is equipped with a liquid surface disturbance device 2.2, a circulating agitator 2.3, and a monitoring device 2.4. Zone 2 (2.8) is equipped with a liquid surface disturbance device 2.9, a circulating agitator 2.10, and a monitoring device 2.11. Zone 3 (2.15) is equipped with a liquid surface disturbance device 2.16, a circulating agitator 2.17, and a monitoring device 2.18.

[0043] Aerobic Zone 1 (2.5) is equipped with an aeration device (2.6) and a monitoring instrument (2.7); Aerobic Zone 2 (2.12) is equipped with an aeration device (2.13) and a monitoring instrument (2.14); Aerobic Zone 3 (2.19) is equipped with an aeration device (2.20) and a monitoring instrument (2.21). The dissolved oxygen (DO) in Aerobic Zone 1 (2.5) is controlled at 0.3-1 mg / L using a rotor flow meter; the DO in Aerobic Zone 2 (2.12) is controlled at 0.5-1.5 mg / L using a rotor flow meter; and the DO in Aerobic Zone 3 (2.19) is controlled at 2-4 mg / L using a rotor flow meter.

[0044] The automatic control system 4 includes an automatic control electrical distribution box 4.1, which controls and connects to the following devices: inlet water pump 1.2, surface agitator 2.2 in anoxic zone 1, internal circulation agitator 2.3 in anoxic zone 1, monitoring device 2.4 in anoxic zone 1, aeration device 2.6 in aerobic zone 1, monitoring device 2.7 in aerobic zone 1, surface agitator 2.9 in anoxic zone 2, internal circulation agitator 2.10 in anoxic zone 2, monitoring device 2.11 in anoxic zone 2, aeration device 2.13 in aerobic zone 2, monitoring device 2.14 in aerobic zone 2, surface agitator 2.16 in anoxic zone 3, internal circulation agitator 2.17 in anoxic zone 3, monitoring device 2.18 in anoxic zone 3, aeration device 2.20 in aerobic zone 3, monitoring device 2.21 in aerobic zone 3, and aeration pump 2.22.

[0045] Example 3

[0046] The present invention also provides an operating method for the device based on a multi-stage A / O process for enhanced simultaneous denitrification and efficient phosphorus removal, as described in Embodiment 1 or Embodiment 2. Figure 1 As shown, the specific operating steps are as follows:

[0047] S1. The multi-stage A / O treatment reactor is inoculated with biological sludge from a municipal wastewater treatment plant, with a sludge concentration of 3000-4000 mg / L. The hydraulic retention time in anoxic zone 1 (2.1) is controlled at 1.5-2.5 h, and the retention time ratio of anoxic zone 1 (2.1), anoxic zone 2 (2.8), and anoxic zone 3 (2.15) is 1:1.3:1.6. The sludge concentration in each anoxic zone is controlled by adjusting the influent ratio, return sludge concentration, and sludge age. The external return ratio is controlled at 80%-150%.

[0048] S2. Wastewater from municipal sewage tank 1.1 enters anoxic zone 1 2.1 via inlet pump 1.2. In anoxic zone 1 2.1, NO3 in the externally returned sludge... - When the -N concentration is 2-10 mg / L, anaerobic ammonia oxidizing bacteria (Anammox) will decompose the remaining NH4+. + -N and NO2 - -N is reduced to N2 and NO3 is produced. - -N, along with denitrifying bacteria absorbing carbon sources, will convert NO3- - -N is reduced to N2, while polyphosphate-accumulating bacteria release PO4. 3- -P, denitrifying polyphosphate-accumulating bacteria utilize NO3- - -N is the electron acceptor pair for PO4. 3 -P is removed to achieve simultaneous nitrogen and phosphorus removal;

[0049] Subsequently, municipal sewage flows into aerobic zone 1 (2.5) through the diversion orifice. The flow meter is adjusted to control the dissolved oxygen (DO) to 0.3-1 mg / L. Aerobic ammonia-oxidizing bacteria and nitrifying bacteria then convert NH4+ into nitrogen dioxide (NH4+). + -N is oxidized to NO2 - -N and NO3 - -N, nitrite accumulation rate 20%-50%, NH4 + With a -N concentration of 1-10 mg / L, the simultaneous denitrification rate can reach 30%-70%, and polyphosphate-accumulating bacteria will convert PO42-... 3- -P is removed to below 0.5-1.5 mg / L, achieving simultaneous nitrogen and phosphorus removal;

[0050] Subsequently, the wastewater flowed into the anoxic zone 2.8, where Anammox released the remaining NH4+. + -N and NO2 - -N is reduced to N2 and NO3 is produced. - -N, along with denitrifying bacteria absorbing carbon sources to convert NO3 - -N is reduced to N2, while polyphosphate-accumulating bacteria release PO4. 3- -P, denitrifying polyphosphate-accumulating bacteria utilize NO3- - -N is the electron acceptor pair for PO4. 3 -P is removed to achieve simultaneous nitrogen and phosphorus removal;

[0051] The nitrification solution flows into aerobic zone 2.12 through the guide hole, with its dissolved oxygen (DO) controlled at 0.5-1.5 mg / L. Unstable short-cut nitrification will cause NH4+ to be released. + -N is oxidized to NO2-N and NO3-N, with a nitrite accumulation rate of 20%-40%, and NH4+ + With a -N concentration of 1-8 mg / L, the simultaneous denitrification rate can reach 20%-60%, and polyphosphate-accumulating bacteria will convert PO42-... 3- -P is removed to below 0.1-1 mg / L, achieving simultaneous nitrogen and phosphorus removal;

[0052] Subsequently, the wastewater flows into the anoxic zone 3, section 2.15, where denitrifying bacteria absorb the carbon source and convert NO3 into nitrogen. - -N is reduced to N2, while polyphosphate-accumulating bacteria release phosphorus PO4. 3- -P, while denitrifying polyphosphate-accumulating bacteria utilize NO3 - -N is the electron acceptor for PO4. 3- The removal of -P enables simultaneous nitrogen and phosphorus removal;

[0053] The solution flows into aerobic zone 3 (2.19) through the guide hole, with DO controlled at 2-4 mg / L to ensure NH4+. + -N is oxidized to NO3. - -N,NH4 + When the -N concentration is 0.1-1 mg / L and the TN concentration is 5-10 mg / L, polyphosphate-accumulating bacteria will produce PO42-. 3- -P is removed to below 0.1-0.5 mg / L, thereby completing deep nitrogen and phosphorus removal;

[0054] S3. The effluent flows into the secondary sedimentation tank 3 through the overflow pipe to complete the sludge-water separation; the sludge at the bottom of the secondary sedimentation tank 3 is returned to the anoxic zone 1 2.1 of the reactor through the return pump 3.2, with a return ratio of 100%-150%; the remaining sludge is discharged from the system through the sludge discharge pipe, and the sludge age is controlled at 15-20 days; under normal operating conditions, the effluent from the secondary sedimentation tank has TN≤10mg / L and NH4+≤10mg / L. + -N≤1 mg / L, TP≤0.3mg / L, COD≤25mg / L;

[0055] S4. During the flood season, in order to actively respond to and effectively control overflow pollution and improve the quality of the aquatic ecosystem, municipal wastewater treatment plants need to be able to operate stably under short-term overload conditions. The influent concentration during the flood season is: TN ≤ 20 mg / L, NH4+ ≤ 20 mg / L. + -N≤20 mg / L, TP≤2mg / L, COD≤100mg / L; influent load during flood season 120%-150%, continuous operation time 5-10 days; adjust external reflux to 100%-150%, and ensure that the influent ratio of anoxic zone 1 is ≥50%; effluent quality of secondary sedimentation tank: TN≤10mg / L, NH4+ +-N≤0.5 mg / L, TP≤0.3mg / L, COD≤20mg / L.

[0056] More specifically, the influent for the experiment was the pretreated effluent from a municipal wastewater treatment plant, with the following daily operating water quality: TN concentration of 45-70 mg / L, NH4+ concentration of... + -N concentration was 40-65 mg / L, TP concentration was 3.6-6.5 mg / L, COD concentration was 170-300 mg / L, and NO2 concentration was... - -N concentration ≤0.3mg / L, NO3 - -N concentration ≤ 0.8 mg / L, pH 7.4–8.1; influent during flood season: TN concentration 14-21 mg / L, NH4+ + -N concentration is 10-18 mg / L, TP concentration is 0.8-2.1 mg / L, COD concentration is 72-110 mg / L, NO2 - -N concentration ≤ 0.1 mg / L, NO3 - -N concentration ≤ 0.3 mg / L, pH 7.1-7.5. The experimental setup is made of stainless steel, and the effective volume of the multi-stage A / O reactor is 15.0 m³. 3 The effective volume of the secondary sedimentation tank is 2.4 m³. 3 .

[0057] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A device for enhancing simultaneous denitrification and efficient phosphorus removal based on a multi-stage A / O process, characterized in that, include: The system includes an inlet device (1), a multi-stage A / O treatment reactor (2), a secondary sedimentation tank (3), and an automatic control system (4). The inlet device (1) is connected to the multi-stage A / O treatment reactor (2), and the multi-stage A / O treatment reactor (2) is connected to the secondary sedimentation tank (3). The automatic control system (4) controls the inlet device (1), the multi-stage A / O treatment reactor (2), and the secondary sedimentation tank (3) respectively, and performs data monitoring and adjustment management. Wastewater from the inlet device (1) enters the multi-stage A / O treatment reactor (2) for denitrification and phosphorus removal. The effluent from the multi-stage A / O treatment reactor (2) flows into the secondary sedimentation tank (3) for sludge-water separation. The sludge at the bottom of the secondary sedimentation tank (3) is returned to the multi-stage A / O treatment reactor (2). The remaining sludge in the secondary sedimentation tank (3) is discharged from the system. The multi-stage A / O treatment reactor (2) includes an anoxic zone; The anoxic zone is equipped with a surface disturbance device, an internal circulation agitator, and an anoxic zone monitoring device. The internal circulation agitator is located at the lower end of the anoxic zone, the surface disturbance device is located at the upper end of the anoxic zone, and the anoxic zone monitoring device is located outside the mixing range of the internal circulation agitator. The sludge in the anoxic zone is uniformly mixed by the internal circulation agitator, and the surface disturbance device inhibits the sludge from floating. The hypoxic zone includes hypoxic zone 1 (2.1), hypoxic zone 2 (2.8), and hypoxic zone 3 (2.15); hypoxic zone 1 (2.1) is equipped with a hypoxic zone 1 liquid surface baffle (2.2), a hypoxic zone 1 internal circulation stirrer (2.3), and a hypoxic zone 1 monitor (2.4); hypoxic zone 2 (2.8) is equipped with a hypoxic zone 2 liquid surface baffle (2.9), a hypoxic zone 2 internal circulation stirrer (2.10), and a hypoxic zone 2 monitor (2.11); hypoxic zone 3 (2.15) is equipped with a hypoxic zone 3 liquid surface baffle (2.16), a hypoxic zone 3 internal circulation stirrer (2.17), and a hypoxic zone 3 monitor (2.18). The secondary sedimentation tank (3) includes a secondary sedimentation tank (3.1), a sludge return pump (3.2), a secondary sedimentation tank monitoring instrument (3.3), and a secondary sedimentation tank backflushing system (3.4). The anoxic zone 3 (2.15) is connected to the secondary sedimentation tank (3.1) through an overflow pipe. The bottom of the secondary sedimentation tank (3.1) is connected to the sludge return pump (3.2) and the secondary sedimentation tank backflushing system (3.4). The secondary sedimentation tank monitoring instrument (3.3) is installed inside the secondary sedimentation tank (3.1) and is electrically connected to the automatic control system (4). The secondary sedimentation tank backwashing system (3.4) is connected to reclaimed water / tap water via a backwash pump. The secondary sedimentation tank monitoring instrument (3.3) monitors the secondary sedimentation tank (3.1) in real time. The secondary sedimentation tank backwashing system (3.4) adjusts the backwashing intensity and frequency to regulate the flow rate, concentration, and pollutant concentration of the returned sludge in the secondary sedimentation tank. 2.The device based on the multi-stage A / O process for strengthening simultaneous denitrification and efficient phosphorus removal according to claim 1, characterized in that, The multi-stage A / O treatment reactor (2) also includes an aerobic zone. The denitrification and phosphorus removal bacteria in the multiple anoxic zones include Anammox, denitrifying bacteria, polyphosphate-accumulating bacteria and denitrifying phosphorus-removing bacteria. The denitrification and phosphorus removal bacteria in the multiple aerobic zones include ammonia-oxidizing bacteria, nitrifying bacteria and polyphosphate-accumulating bacteria. The multiple anoxic zones and multiple aerobic zones are distributed alternately, and two adjacent anoxic zones and aerobic zones are connected through guide holes. The aerobic zone includes aerobic zone 1 (2.5), aerobic zone 2 (2.12), and aerobic zone 3 (2.19). The anoxic zone 1 (2.1), aerobic zone 1 (2.5), anoxic zone 2 (2.8), aerobic zone 2 (2.12), anoxic zone 3 (2.15), and aerobic zone 3 (2.19) are connected in sequence. The water inlet device (1) is connected through anoxic zone 1 (2.1), and the aerobic zone 3 (2.19) is connected to the secondary sedimentation tank (3). 3.The device based on the multi-stage A / O process for strengthening simultaneous denitrification and efficient phosphorus removal according to claim 2, characterized in that, An aeration device is provided at the bottom of the aerobic zone, and an aerobic zone monitor is provided at the top of the aerobic zone. The aeration device is connected to an aeration pump (2.22) via a rotor flow meter, and the aeration pump (2.22) is electrically connected to the automatic control system (4). The aerobic zone 1 (2.5) is equipped with an aerobic zone 1 aeration device (2.6) and an aerobic zone 1 monitoring instrument (2.7). The aerobic zone 2 (2.12) is equipped with an aerobic zone 2 aeration device (2.13) and an aerobic zone 2 monitoring instrument (2.14). The aerobic zone 3 (2.19) is equipped with an aerobic zone 3 aeration device (2.20) and an aerobic zone 3 monitoring instrument (2.21).

4. The device for enhancing simultaneous denitrification and efficient phosphorus removal based on a multi-stage A / O process according to claim 3, characterized in that, The DO in aerobic zone 1 (2.5) is controlled to be 0.3-1 mg / L by a rotor flow meter, the DO in aerobic zone 2 (2.12) is controlled to be 0.5-1.5 mg / L by a rotor flow meter, and the DO in aerobic zone 3 (2.19) is controlled to be 2-4 mg / L by a rotor flow meter.

5. The device for enhancing simultaneous denitrification and efficient phosphorus removal based on the multi-stage A / O process according to claim 2, characterized in that, The water inlet device (1) includes a municipal sewage tank (1.1) and an inlet water pump (1.2), and the municipal sewage tank (1.1) is connected to the anoxic zone 1 (2.1) through the inlet water pump (1.2).

6. The device for enhancing simultaneous denitrification and efficient phosphorus removal based on the multi-stage A / O process according to claim 3 or 5, characterized in that, The automatic control system (4) includes an automatic control electrical distribution box (4.1), which controls and connects to the inlet water pump (1.2), the surface disturbance device (2.2) in the anoxic zone 1, the circulating agitator (2.3) in the anoxic zone 1, the monitoring device (2.4) in the anoxic zone 1, the aeration device (2.6) in the aerobic zone 1, the monitoring device (2.7) in the aerobic zone 1, the surface disturbance device (2.9) in the anoxic zone 2, and the circulating agitator (2.9) in the anoxic zone 2. The following components are included: a circulating agitator (2.10), an anoxic zone 2 monitor (2.11), an aerobic zone 2 aeration device (2.13), an aerobic zone 2 monitor (2.14), an anoxic zone 3 liquid surface disturbance device (2.16), an anoxic zone 3 internal circulating agitator (2.17), an anoxic zone 3 monitor (2.18), an aerobic zone 3 aeration device (2.20), an aerobic zone 3 monitor (2.21), and an aeration pump (2.22).

7. The operation method of the device for enhancing simultaneous nitrogen removal and efficient phosphorus removal based on the multi-stage A / O process according to claim 5, characterized in that, The specific operating steps are as follows: S1. Turn on the equipment and control the hydraulic residence time, influent ratio and external return ratio of the anoxic zone through the automatic control electrical distribution box (4.1); S2. The municipal sewage in the municipal sewage tank (1.1) enters the anoxic zone 1 (2.1) through the inlet water pump (1.2). The sewage and external return sludge in the anoxic zone 1 (2.1) pass through multiple anoxic zones and multiple aerobic zones in sequence to remove nitrogen and phosphorus. S3. The effluent from the aerobic zone 3 (2.19) flows into the secondary sedimentation tank (3.1) through the overflow pipe for mud-water separation. The sludge at the bottom of the secondary sedimentation tank (3.1) is returned to the anoxic zone 1 (2.1) through the sludge return pump (3.2). The remaining sludge in the secondary sedimentation tank (3.1) is discharged from the system through the sludge discharge pipe. 8.The method according to claim 7, wherein, The sludge return ratio at the bottom of the secondary sedimentation tank (3.1) is 80%-150%.

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