Integrated Sewage Treatment Device and Method Applicable to Fluctuations in Inlet Water Quality

Abstract

The present invention discloses an integrated sewage treatment device and method suitable for fluctuating influent water quality, which includes an oxygen consumption zone, an anaerobic zone, an anoxic zone, an aerobic-anaerobic zone, an aerobic zone and an effluent channel connected in sequence. The aerobic zone includes an aerobic water distribution zone, an aerobic sedimentation zone and an aerobic reflux zone. The aerobic-anaerobic zone is connected to the aerobic water distribution zone, the aerobic water distribution zone is connected to the aerobic sedimentation zone, the upper part of the aerobic sedimentation zone is connected to the effluent channel, and the lower part of the aerobic sedimentation zone is connected to the aerobic reflux zone. The aerobic reflux zone returns a part of the sludge to the oxygen consumption zone and the anoxic zone respectively through a reflux pump, and discharges the remaining sludge through a sludge pump. The present invention is provided with multiple aerobic-anaerobic partitions between the anoxic zone and the aerobic zone, which increases the flexibility of the operating conditions, ensures the low-energy consumption operation of the system, and at the same time, through a special structural form, places the sedimentation zone in the aerobic zone, while ensuring the sedimentation effect, reduces the head required for sludge reflux, and further reduces the operating energy consumption of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an integrated sewage treatment device and method suitable for fluctuating influent water quality. Background Art

[0002] In recent years, with the rapid development of my country's urban economy, the amount of urban sewage has increased rapidly, and the urban sewage treatment capacity has been rapidly improved. As of 2018, my country's sewage treatment capacity has reached 228 million cubic meters per day. The activated sludge process has been widely used in urban sewage treatment plants due to its advantages in energy consumption and economy.

[0003] The influent quality and quantity of existing urban sewage treatment plants fluctuate greatly. The traditional process ensures that the effluent ammonia nitrogen meets the standard by sufficient aeration in the aerobic section, and ensures the denitrification function in the anoxic zone by adding carbon sources, thereby ensuring that the effluent total nitrogen meets the standard, which leads to high energy consumption in the operation of the traditional sewage treatment process. In addition, the traditional process separates the biological reactor from the secondary sedimentation tank, which increases the head required for sludge return, resulting in high energy consumption for sludge return in the system. With the introduction of the concept of "carbon neutrality", higher requirements have been put forward for energy conservation and emission reduction in sewage treatment plants. The current sewage treatment process is difficult to meet the needs of low-carbon development of sewage treatment.

[0004] In order to solve the problems of large fluctuations in influent water quality and water volume in urban sewage plants and high energy consumption in sewage treatment process operation, the present invention proposes an integrated sewage treatment device and method suitable for fluctuating influent water quality. Summary of the invention

[0005] In order to solve the problems of large fluctuations in influent water quality and water volume in urban sewage treatment plants and high energy consumption in sewage treatment process operation, the present invention provides an integrated sewage treatment device and method suitable for influent water quality fluctuations. The present invention provides a plurality of anoxic partitions between the anoxic zone and the aerobic zone to increase the flexibility of the operating conditions and ensure low-energy operation of the system. At the same time, through a special structural form, the sedimentation zone is placed in the aerobic zone. While ensuring the sedimentation effect, the head required for sludge return is reduced, thereby further reducing the system operation energy consumption.

[0006] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0007] An integrated sewage treatment device applicable to fluctuating influent water quality, comprising an oxygen consumption zone, an anaerobic zone, an anoxic zone, an aerobic-anaerobic zone, an aerobic zone and an effluent channel connected in sequence. The aerobic zone includes an aerobic water distribution zone, an aerobic sedimentation zone and an aerobic reflux zone. The aerobic-anaerobic zone is connected to the aerobic water distribution zone, the aerobic water distribution zone is connected to the aerobic sedimentation zone, the upper part of the aerobic sedimentation zone is connected to the effluent channel, the lower part of the aerobic sedimentation zone is connected to the aerobic reflux zone. The aerobic reflux zone returns a part of the sludge to the oxygen consumption zone and the anoxic zone respectively through a reflux pump, and discharges the remaining sludge through a sludge pump.

[0008] Preferably, the aerobic-anaerobic zone consists of multiple aerobic-anaerobic sub-zones.

[0009] Preferably, the effluent channel is located above the aerobic water distribution zone, and the two are completely separated by a pool wall; the aerobic water distribution zone and the aerobic reflux zone are respectively located on both sides of the aerobic sedimentation zone.

[0010] Preferably, stirrers are arranged in the oxygen consumption zone, anaerobic zone, anoxic zone and aerobic-anaerobic zone; aeration devices are arranged in the aerobic-anaerobic zone, aerobic water distribution zone, aerobic sedimentation zone and aerobic reflux zone.

[0011] Preferably, the aerobic sedimentation zone includes an influent diversion plate, a partition plate, inclined tube fillers, an effluent trough and a fluid guide. The inclined tube fillers are arranged in the upper part of the aerobic sedimentation zone, partition plates are closely arranged on both sides of the inclined tube fillers, the effluent trough is located above the inclined tube fillers and between the partition plates on both sides, the influent diversion plate is arranged outside the partition plate and has a gap with it, and the fluid guide is arranged at the bottom outlet of the influent diversion plate.

[0012] Further preferably, the distance between the top of the inclined tube fillers and the bottom of the effluent trough is 0.5 - 1.0 m; the distance between the top of the partition plate and the bottom of the effluent trough is 1.0 - 2.0 m, and the depth of the pool body of the aerobic sedimentation zone is not less than 6 m.

[0013] Further preferably, the influent diversion plate consists of a vertical plate and an inclined plate. The vertical plate is located outside the partition plate, the inclined plate is located below the partition plate, the included angle between the vertical plate and the inclined plate is not less than 145°, and the liquid flow velocity between the vertical plate and the partition plate is less than 0.1 m / s.

[0014] Further preferably, the width of the fluid guide is 0.5 - 1.5 m larger than the width of the bottom gap of the influent diversion plate; the upper inclination angle of the fluid guide is not less than 55°.

[0015] An integrated sewage treatment method applicable to fluctuating influent water quality, comprising the following steps:

[0016] Step 1: The sewage enters the deoxygenation zone, anaerobic zone, anoxic zone, facultative oxygen zone, aerobic water distribution zone, and aerobic sedimentation zone in sequence.

[0017] Step 2: The sewage that has reached the purification standard is discharged into the effluent channel through the effluent trough in the aerobic sedimentation zone.

[0018] Step 3: Part of the mud-water mixture in the aerobic sedimentation zone is refluxed to the deoxygenation zone and anoxic zone through the reflux pump, and part is discharged as surplus sludge through the sludge pump.

[0019] Step 4: When the influent TN ≥ 30 mg / L and the influent COD / TN ≥ 8, the aeration device in the facultative oxygen I zone starts to work and the agitator stops working, the aeration devices in the facultative oxygen II zone and facultative oxygen III zone stop working and the agitator starts to work, the reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%; among them, when the influent TN ≥ 30 mg / L and the influent COD / TN ≥ 8, the influent carbon source is relatively sufficient. It is found that by operating the facultative oxygen I zone aerobically and the facultative oxygen II zone and facultative oxygen III zone anoxically, the storage capacity of carbon source by the system microorganisms can be strengthened, heterotrophic nitrifying bacteria and endogenous carbon source denitrifying bacteria can be enriched in the system. In the anaerobic zone, the microorganisms convert more carbon source in the sewage into endogenous carbon source. In the facultative oxygen I zone, through the dual action of heterotrophic and autotrophic nitrifying bacteria, the nitrification (converting NH 4 + -N into NO 3 - -N) capacity of the system is strengthened, the aerobic time is reduced, and thus the aeration energy consumption is reduced. Subsequently, in the facultative oxygen II zone and facultative oxygen III zone, under the action of endogenous carbon source denitrifying bacteria, the denitrification (converting NO 3 - -N into N 2 ) capacity of the system is strengthened, the efficient removal of TN is achieved, and the lower NO 3 - -N is refluxed to the deoxygenation zone through the reflux pump, avoiding the competition for carbon source between polyphosphate-accumulating bacteria and denitrifying bacteria, and thus effectively improving the phosphorus removal capacity of the system.

[0020] Step 5: When the influent TN ≥ 30 mg / L and the influent COD / TN < 8, the aeration device in the facultative oxygen I zone stops working and the agitator starts to work, the aeration devices in the facultative oxygen II zone and facultative oxygen III zone start to work and the agitator stops working, the reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 200% - 400%; among them, when the influent TN ≥ 30 mg / L and the influent COD / TN ≥ 8, the influent carbon source is relatively tense. It is found that the aerobic zone will consume more carbon source. To avoid this situation, in Step 5, the reflux ratio to the anoxic zone is increased, the facultative oxygen I zone is operated anoxically, so that more NO 3- -N and the carbon source perform denitrification in the anoxic zone, effectively preventing the carbon source from entering the aerobic zone and being consumed. More NO 3 - -N undergoes denitrification removal in the anoxic zone, effectively improving the TN removal rate. At the same time, lower NO 3 - -N is refluxed to the anoxic zone through a reflux pump, avoiding competition for the carbon source between polyphosphate-accumulating organisms and denitrifying bacteria, and thus effectively improving the phosphorus removal capacity of the system.

[0021] Step 6: When the influent TN is 20 mg / L ≤ TN < 30 mg / L, the aeration device in the facultative I zone starts working and the stirrer stops working. The aeration devices in the facultative II zone and the facultative III zone stop working and the stirrer starts working. The reflux ratio of the reflux pump to the anoxic zone is controlled at 50% - 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%. Among them, when the influent TN is 20 mg / L ≤ TN < 30 mg / L, the influent TN concentration is relatively low, and the system has less pressure to remove TN. To minimize the system operation energy consumption, the aeration in the facultative II zone and the facultative III zone is stopped, and the reflux ratio of the system to the anoxic zone is reduced. In addition, the facultative II zone and the facultative III zone are changed to anoxic zones, which can strengthen the denitrifying bacteria of the carbon source in the system and enhance the TN removal rate of the system. At the same time, the reflux ratio to the anoxic zone is reduced. On the one hand, it reduces the system operation energy consumption, and on the other hand, it reduces NO 3 - -N is refluxed to the anoxic zone through a reflux pump, avoiding competition for the carbon source between polyphosphate-accumulating organisms and denitrifying bacteria, and thus effectively improving the phosphorus removal capacity of the system.

[0022] Step 7: When the influent TN < 20 mg / L, the aeration devices in the facultative I zone and the facultative II zone stop working and the stirrer starts working. The aeration device in the facultative III zone starts working and the stirrer stops working. The reflux ratio of the reflux pump to the anoxic zone is controlled at 50% - 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%. Among them, when the influent TN < 20 mg / L, the influent TN concentration is very low, and the system has very little pressure to remove TN. To minimize the system operation energy consumption, the aeration in the facultative I zone and the facultative II zone is stopped, and the facultative III zone with the shortest residence time is aerated. At the same time, it also reduces the consumption of the carbon source during the aeration process, ensuring the high-efficiency phosphorus and nitrogen removal capacity of the system.

[0023] Step 8: Repeat steps 1 - 7 to complete the efficient removal of urban sewage with low energy consumption.

[0024] Preferably, the residence time in the deoxygenation zone is 0.5 - 1 h, the residence time in the anaerobic zone is 1 - 2 h, the residence time in the anoxic zone is 2 - 4 h, the residence time in the facultative oxygenation zone I is 1 - 3 h, the residence time in the facultative oxygenation zone II is 1 - 3 h, the residence time in the facultative oxygenation zone III is 0.5 - 1 h, and the residence time in the aerobic sedimentation zone is 4 - 8 h.

[0025] Compared with the prior art, the present invention mainly has the following advantages and effects:

[0026] 1. Strong adaptability to influent water quality fluctuations: The present invention adopts the form of continuous influent and continuous effluent for treating municipal sewage. There are multiple facultative oxygenation zones arranged between the anoxic zone and the aerobic zone. The operating conditions of the facultative oxygenation zones and the reflux pumps are linked with the influent water quality, greatly improving the adaptability of the reaction device to the influent water quality fluctuations and ensuring the stable operation of the system with low energy consumption and up-to-standard discharge.

[0027] 2. Low operating energy consumption: Generally, for sludge reflux, it is necessary to first transfer the sludge in the sedimentation zone to the sludge reflux pump house (there is a head difference of about 2 m - 4 m between them), and then transport the sludge to the deoxygenation zone through the sludge reflux pump house. Through a special structural form, the present invention places the sedimentation zone in the aerobic zone, which can omit this part of the head difference. While ensuring the sedimentation effect, it also reduces the floor area, saves the investment cost, and reduces the head required for sludge reflux, further reducing the operating energy consumption of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic plan layout structure diagram of the integrated sewage treatment device of the present invention;

[0029] Figure 2 is Figure 1 a schematic cross-sectional structure diagram in the 1 - 1 direction in

[0030] Figure 3 is Figure 1 a schematic cross-sectional structure diagram in the 2 - 2 direction in

[0031] In the figure: 1 - deoxygenation zone; 2 - anaerobic zone; 3 - anoxic zone; 4 - facultative oxygenation zone; 41 - facultative oxygenation zone I; 42 - facultative oxygenation zone II; 43 - facultative oxygenation zone III; 5 - aerobic zone; 51 - aerobic water distribution zone; 52 - aerobic sedimentation zone; 521 - influent diversion plate; 5211 - vertical plate; 5212 - inclined plate; 522 - partition plate; 523 - inclined tube packing; 524 - effluent trough; 525 - fluid guide body; 53 - aerobic reflux zone; 6 - effluent channel; 7 - reflux pump; 8 - sludge pump; 9 - aeration device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation of the present invention will be described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent; for better illustration of this embodiment, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent.

[0033] As Figures 1-3 shown, an integrated sewage treatment device suitable for fluctuating influent water quality includes an oxygen-consuming area 1, an anaerobic area 2, an anoxic area 3, an anoxic-aerobic area 4, an aerobic area 5 and an effluent channel 6 that are connected in sequence. The aerobic area 5 includes an aerobic water distribution area 51, an aerobic sedimentation area 52 and an aerobic reflux area 53. The anoxic-aerobic area 4 is connected to the aerobic water distribution area 51, the aerobic water distribution area 51 is connected to the aerobic sedimentation area 52, the upper part of the aerobic sedimentation area 52 is connected to the effluent channel 6, the lower part of the aerobic sedimentation area 52 is connected to the aerobic reflux area 53, and the aerobic reflux area 53 returns part of the sludge to the oxygen-consuming area 1 and the anoxic area 3 respectively through a reflux pump 7, and discharges part of the sludge through a sludge pump 8 in the aerobic reflux area 53.

[0034] Among them, the anoxic-aerobic area 4 is composed of multiple anoxic-aerobic sub-areas, namely anoxic-aerobic area I 41, anoxic-aerobic area II 42, and anoxic-aerobic area III 43 that are connected in sequence. Agitators are provided in the oxygen-consuming area 1, anaerobic area 2, anoxic area 3, and anoxic-aerobic area 4; aeration devices 9 are provided in the anoxic-aerobic area 4, aerobic water distribution area 51, aerobic sedimentation area 52, and aerobic reflux area 53.

[0035] The effluent channel 6 is located above the aerobic water distribution area 51, and the two are completely separated by the pool wall; the aerobic water distribution area 51 and the aerobic reflux area 53 are located on both sides of the aerobic sedimentation area 52 respectively. The sewage in the aerobic water distribution area 51 flows into the aerobic sedimentation area 52 through holes. After the sewage is sedimented, the supernatant flows into the effluent channel 6 through the effluent trough 524, and the sludge enters the aerobic reflux area 53.

[0036] The aerobic sedimentation area 52 includes an inlet flow guide plate 521, a partition plate 522, inclined tube fillers 523, an effluent trough 524 and a flow guide body 525. The inclined tube fillers 523 are arranged in the upper part of the aerobic sedimentation area 52. Partition plates 522 are closely arranged on both sides of the inclined tube fillers 523. The effluent trough 524 is located above the inclined tube fillers 523 and between the partition plates 522 on both sides. The inlet flow guide plate 521 is arranged outside the partition plate 522 and forms an inlet channel with it. The flow guide body 525 is arranged at the bottom outlet of the inlet flow guide plate 521.

[0037] Among them, the distance between the top of the inclined tube packing 523 and the bottom of the water outlet tank 524 is 0.5 - 1.0 m; the distance between the top of the partition plate 522 and the bottom of the water outlet tank 524 is 1.0 - 2.0 m, and the depth of the pool body of the aerobic sedimentation area 52 is not less than 6 m. Further preferably, the inlet diversion plate 521 is composed of a vertical plate 5211 and an inclined plate 5212. The vertical plate 5211 is located outside the partition plate 522, and the inclined plate 5212 is located below the partition plate 522. The included angle between the vertical plate 5211 and the inclined plate 5212 is not less than 145°, and the liquid flow rate between the vertical plate 5211 and the partition plate 522 is less than 0.1 m / s. Further preferably, the width of the fluid guide 525 is 0.5 - 1.5 m larger than the width of the gap at the bottom of the inlet diversion plate 521; the upper inclination angle of the fluid guide 525 is not less than 55°.

[0038] The present invention is implemented according to the following steps:

[0039] 1) Adopt the form of continuous water inlet and continuous water outlet, and the aeration air-water ratio in the aerobic zone of the biological reaction tank is 4.5;

[0040] 2) The activated sludge concentration in the biological reaction tank is maintained at 4000 mg / L;

[0041] 3) The residence time in the deoxygenation zone is 0.5 h, the residence time in the anaerobic zone is 1 h, the residence time in the anoxic zone is 3 h, the residence time in the facultative oxygen I zone is 2 h, the residence time in the facultative oxygen II zone is 2 h, the residence time in the facultative oxygen III zone is 1 h, and the residence time in the aerobic sedimentation area is 6 h;

[0042] 4) When the influent COD is 360 mg / L, NH 4 + -N is 36 mg / L, TN is 40 mg / L, and TP is 4.6 mg / L:

[0043] The aeration device in the facultative oxygen I zone 41 starts to work, and the agitator stops working. The aeration devices in the facultative oxygen II zone 42 and the facultative oxygen III zone 43 stop working, and the agitator starts to work. The reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 200%; the effluent COD, NH 4 + -N, TN, and TP concentrations are 24 mg / L, 0.42 mg / L, 8.65 mg / L, and 0.32 mg / L respectively. The effluent water quality is better than the requirements of Class A of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"

[0044] (GB18918 - 2002).

[0045] 5) When the influent COD is 230 mg / L, NH 4 +When COD is 33 mg / L, TN is 36 mg / L, and TP is 4.2 mg / L:

[0046] The aeration device in the first anoxic zone 41 stops working and the stirrer starts working. The aeration devices in the second anoxic zone 42 and the third anoxic zone 43 start working and the stirrers stop working. The reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 300%. The effluent COD, NH 4 + -N, TN, and TP concentrations are 22 mg / L, 0.36 mg / L, 9.26 mg / L, and 0.28 mg / L respectively. The effluent quality is better than the requirements of Grade A of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0047] 6) When the influent COD is 180 mg / L, NH 4 + -N is 24 mg / L, TN is 26 mg / L, and TP is 3.5 mg / L:

[0048] The aeration device in the first anoxic zone 41 starts working and the stirrer stops working. The aeration devices in the second anoxic zone 42 and the third anoxic zone 43 stop working and the stirrers start working. The reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100%. The effluent COD, NH 4 + -N, TN, and TP concentrations are 21 mg / L, 0.28 mg / L, 8.38 mg / L, and 0.26 mg / L respectively. The effluent quality is better than the requirements of Grade A of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0049] 7) When the influent COD is 120 mg / L, NH 4 + -N is 15 mg / L, TN is 18 mg / L, and TP is 2.6 mg / L: The aeration devices in the first anoxic zone 41, the second anoxic zone 42, and the third anoxic zone 43 stop working and the stirrers start working. The aeration device in the third anoxic zone 43 starts working and the stirrer stops working. The reflux ratio of the reflux pump to the deoxygenation zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100%. The effluent COD, NH 4 + -N, TN, and TP concentrations are 18 mg / L, 0.26 mg / L, 7.36 mg / L, and 0.24 mg / L respectively. The effluent quality is better than the

[0050] requirements of Grade A of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002).

[0051] It can be seen that the method of the present invention is an integrated sewage treatment device and method applicable to fluctuations in influent water quality.

[0052] Based on the description and drawings of the present invention, those skilled in the art can easily manufacture or use an integrated sewage treatment device and method of the present invention applicable to fluctuations in influent water quality, and can achieve the positive effects recorded in the present invention.

[0053] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms used to describe the orientation or positional relationship in the present invention are only for illustrative purposes and should not be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood in combination with the drawings and according to specific circumstances.

[0054] Unless otherwise clearly specified and defined, in the present invention, if there are terms such as "set", "connected" and "connected", they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] The above are only the preferred implementation schemes of the present invention, but the present invention is not limited to the above specific implementation schemes. Without departing from the principle of the present invention, those of ordinary skill in the art can make several modifications, supplements, or use similar methods for substitution, which should also be regarded as the protection scope of the present invention.

Claims

1. An integrated sewage treatment method applicable to fluctuating influent water quality, characterized in that, it includes using an integrated sewage treatment device, which includes an oxygen-consuming zone, an anaerobic zone, an anoxic zone, an aerobic-anaerobic zone, an aerobic zone and an effluent channel connected in sequence. The aerobic zone includes an aerobic water distribution area, an aerobic sedimentation area and an aerobic reflux area. The aerobic-anaerobic zone is connected to the aerobic water distribution area, the aerobic water distribution area is connected to the aerobic sedimentation area, the upper part of the aerobic sedimentation area is connected to the effluent channel, the lower part of the aerobic sedimentation area is connected to the aerobic reflux area. The aerobic reflux area returns part of the sludge to the oxygen-consuming zone and the anoxic zone respectively through a reflux pump, and discharges the remaining part of the sludge through a sludge pump; the aerobic-anaerobic zone is composed of multiple aerobic-anaerobic sub-zones, which are aerobic-anaerobic Zone I, aerobic-anaerobic Zone II, and aerobic-anaerobic Zone III connected in sequence; The integrated sewage treatment method using the integrated sewage treatment device includes the following steps: Step 1: Sewage enters the oxygen-consuming zone, anaerobic zone, anoxic zone, aerobic-anaerobic zone, aerobic water distribution area, and aerobic sedimentation area in sequence; Step 2: The purified and treated sewage is discharged into the effluent channel through the effluent trough in the aerobic sedimentation area; Step 3: Part of the mud-water mixture in the aerobic sedimentation area is refluxed to the oxygen-consuming zone and the anoxic zone through a reflux pump, and part is discharged as excess sludge through a sludge pump; Step 4: When the influent TN ≥ 30 mg / L and the influent COD / TN ≥ 8, the aeration device in the aerobic-anaerobic Zone I starts to work and the stirrer stops working. The aeration devices in the aerobic-anaerobic Zone II and aerobic-anaerobic Zone III stop working and the stirrers start to work. The reflux ratio of the reflux pump to the oxygen-consuming zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%; Step 5: When the influent TN ≥ 30 mg / L and the influent COD / TN < 8, the aeration device in the aerobic-anaerobic Zone I stops working and the stirrer starts to work. The aeration devices in the aerobic-anaerobic Zone II and aerobic-anaerobic Zone III start to work and the stirrers stop working. The reflux ratio of the reflux pump to the oxygen-consuming zone is controlled at 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 200% - 400%; Step 6: When 20 mg / L ≤ influent TN < 30 mg / L, the aeration device in the aerobic-anaerobic Zone I starts to work and the stirrer stops working. The aeration devices in the aerobic-anaerobic Zone II and aerobic-anaerobic Zone III stop working and the stirrers start to work. The reflux ratio of the reflux pump to the oxygen-consuming zone is controlled at 50% - 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%; Step 7: When the influent TN < 20 mg / L, the aeration devices in the aerobic-anaerobic Zone I, aerobic-anaerobic Zone II, and aerobic-anaerobic Zone III stop working and the stirrers start to work. The aeration device in the aerobic-anaerobic Zone III starts to work and the stirrer stops working. The reflux ratio of the reflux pump to the oxygen-consuming zone is controlled at 50% - 100%, and the reflux ratio of the reflux pump to the anoxic zone is controlled at 100% - 200%; Step 8: Repeat Steps 1 - 7 to complete the efficient removal of urban sewage with low energy consumption.

2. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 1, characterized in that: the aerobic-anaerobic zone is composed of multiple aerobic-anaerobic sub-zones.

3. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 1, characterized in that: The effluent channel is located above the aerobic distribution area, and the two are completely separated by the pool wall; the aerobic distribution area and the aerobic return area are respectively located on both sides of the aerobic sedimentation area.

4. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 1, characterized in that: Stirrers are arranged in the deoxygenation area, anaerobic area, anoxic area, and facultative oxygenation area; aeration devices are arranged in the facultative oxygenation area, aerobic distribution area, aerobic sedimentation area, and aerobic return area.

5. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 1, characterized in that: The aerobic sedimentation area includes an influent diversion plate, a partition plate, inclined tube fillers, an effluent trough, and a flow guide body. The inclined tube fillers are arranged in the upper part of the aerobic sedimentation area. Partition plates are closely arranged on both sides of the inclined tube fillers. The effluent trough is located above the inclined tube fillers and between the partition plates on both sides. The influent diversion plate is arranged outside the partition plate and has a gap therewith. The flow guide body is arranged at the bottom outlet of the influent diversion plate.

6. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 5, characterized in that: The distance between the top of the inclined tube fillers and the bottom of the effluent trough is 0.5 - 1.0 m; the distance between the top of the partition plate and the bottom of the effluent trough is 1.0 - 2.0 m, and the depth of the pool body of the aerobic sedimentation area is not less than 6 m.

7. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 5, characterized in that: The influent diversion plate is composed of a vertical plate and an inclined plate. The vertical plate is located outside the partition plate, and the inclined plate is located below the partition plate. The included angle between the vertical plate and the inclined plate is not less than 145°, and the liquid flow velocity between the vertical plate and the partition plate is less than 0.1 m / s.

8. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 5, characterized in that: The width of the flow guide body is 0.5 - 1.5 m larger than the width of the bottom gap of the influent diversion plate; the upper inclination angle of the flow guide body is not less than 55°.

9. The integrated sewage treatment method applicable to fluctuating influent water quality according to claim 1, characterized in that, The residence time in the deoxygenation area is 0.5 - 1 h, the residence time in the anaerobic area is 1 - 2 h, the residence time in the anoxic area is 2 - 4 h, the residence time in the facultative oxygenation I area is 1 - 3 h, the residence time in the facultative oxygenation II area is 1 - 3 h, the residence time in the facultative oxygenation III area is 0.5 - 1 h, and the residence time in the aerobic sedimentation area is 4 - 8 h.

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