Horizontal opposed synchronous biological nitrogen and phosphorus removal MBR (membrane bioreactor) sewage treatment method

Abstract

The invention discloses a horizontally opposed synchronous biological nitrogen and phosphorus removal MBR (membrane bioreactor) sewage treatment method, which adopts a horizontally opposed parallel architecture design that an aerobic membrane tank is directly coupled with an anaerobic tank and an anoxic tank to realize automatic synchronization, function switching and independent regulation and control of biological nitrogen and phosphorus removal. Comprising the following steps: sewage is firstly pretreated and then is simultaneously delivered to an anaerobic tank and an anoxic tank in proportion; the anaerobic tank is directly coupled with the aerobic membrane tank to form a biological phosphorus removal cycle, and the anoxic tank is directly coupled with the aerobic membrane tank to form a biological nitrogen removal cycle. The aerobic membrane tank is filled with a membrane component, the downstream side of the aerobic membrane tank is communicated with the separation area, and the separation area is provided with an upper-layer nitrification liquid backflow system, a middle-layer sludge backflow system and a lower-layer phosphorus-rich sludge fixed-discharge system. According to the technical scheme, the internal contradiction that biological nitrogen removal needs low load and long sludge age, and biological phosphorus removal needs high load and short sludge age is solved, function exchange of an anaerobic zone and an anoxic zone can be achieved, nitrogen removal priority or phosphorus removal priority can be switched, and the biological nitrogen and phosphorus removal effect can be independently regulated and controlled.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, and particularly to a horizontal opposed type synchronous biological nitrogen and phosphorus removal MBR sewage treatment method. Background Art

[0002] The sewage treatment originated from the activated sludge process invented by E. Ardern and W.T. Lockett in 1914, and the technical original intention was to solve the problems of ammonia nitrogen, BOD 5 and SS exceeding the standard related to black odor. With the acceleration of the global industrialization process, TN and TP in the biochemical tail water have increasingly aggravated the eutrophication of downstream rivers and lakes. In the 1980s, J. Barnard invented the biological nitrogen and phosphorus removal process based on the AAO core. Since the large-scale commercial use started in the 1990s abroad / 2000s in China, it has been more than thirty years. Persistently reducing nitrogen and controlling phosphorus has basically curbed the trend of eutrophication, and the achievements in water environment improvement are remarkable worldwide.

[0003] In the engineering practice of the past thirty years, the technical scheme invented by J. Barnard has undergone multiple fine-tuning, but the AAO process core (that is, the "in-line series of biological phosphorus removal cycle embedded in the nitrogen removal cycle" architecture) has never changed (as shown in the following figure).

[0004]

[0005] The current national standard GB50014-2021 "Outdoor Drainage Design Standard" states on page 206 that "in the AAO process, nitrogen removal requires a lower load and a longer sludge age, while phosphorus removal requires a higher load and a shorter sludge age. When the nitrogen removal effect is good, the phosphorus removal effect is poor. Vice versa, it is impossible to achieve good effects simultaneously...". In-depth analysis reveals that the in-line series architecture of the AAO process core has the following six major drawbacks that have not been overcome so far:

[0006] A. The internal requirements of biological nitrogen and phosphorus removal for sludge age and load are contradictory and cannot be solved;

[0007] B. The biological nitrogen removal cycle is restricted by the "detour" of the upstream available carbon source embedded outside and the fierce competition of anaerobic sludge. Incomplete denitrification limits the biological nitrogen removal effect;

[0008] C. The biological phosphorus removal cycle is restricted by the "detour" of the downstream anoxic tank embedded inside. Insufficient anaerobic phosphorus release and fierce competition of anoxic sludge result in poor aerobic phosphorus uptake effect, thus restricting biological phosphorus removal;

[0009] D. The nitrification liquid reflux entrains too much DO and heterotrophic bacteria, seriously interfering with the anoxic denitrification process;

[0010] E. The sludge reflux entrains too much combined oxygen (such as nitrate nitrogen, etc.) and heterotrophic bacteria, seriously damaging the anaerobic phosphorus release process;

[0011] F. The liquid-solid separation efficiency of the secondary sedimentation tank is low, and the nitrifying bacteria with a generation period of up to 5 days are vulnerable to impact and loss.

[0012] In recent years, the AAO-MBR process following the "in-line series of biological phosphorus removal cycle embedded in the denitrification cycle" architecture has been widely promoted on a large scale. Its prominent advantage is that UF and MF membrane modules are used to replace the secondary sedimentation tank to prevent the loss of nitrifying bacteria. The prominent disadvantage is that three-stage reflux must be set, increasing the reflux power consumption by 2 to 3 times (hereinafter referred to as "disadvantage G"), that is, from the membrane tank to the aerobic tank (reflux ratio 400%-600%), from the aerobic tank to the anoxic tank (reflux ratio 300%-500%), and from the anoxic tank to the anaerobic tank (reflux ratio 100%-200%). Obviously, although disadvantage F has been overcome, disadvantages A to E still remain unsolved, and disadvantage G has been added.

[0013] In engineering practice, taking the above-mentioned disadvantage B as an example, the sewage treatment operation and maintenance entity often solves the problem of local carbon source shortage in a "headache-treatment-for-headache, footache-treatment-for-footache" manner, and chooses to add commercial carbon sources such as sodium acetate (3,000 yuan / ton) or methanol (2,000 yuan / ton) to the anoxic tank. The improvement of the denitrification effect is immediate, but it will inevitably increase the drug consumption per ton of water by 0.1 to 0.5 yuan! However, once the carbon source is stopped being added, the risk of total nitrogen exceeding the standard in the effluent will continue to rise, forming a vicious cycle.

[0014] Therefore, there is an urgent need to provide a biological denitrification and phosphorus removal method with a short process, automatic synchronization, free switching, and independent regulation, to replace the "in-line series of biological phosphorus removal cycle embedded in the denitrification cycle" architecture of the existing AAO process core, and to solve the "stuck-neck" century problem of the mutual restraint between biological denitrification and biological phosphorus removal, so as to meet the multi-level and multi-scale practical needs of pollution reduction, carbon emission reduction, cost control, efficiency improvement, quality improvement, capacity expansion, customized operation and maintenance, etc. Summary of the Invention

[0015] The purpose of the present invention is to overcome the above-mentioned disadvantages A to G of the background technology, and provide a synchronous biological denitrification and phosphorus removal MBR sewage treatment method, which adopts a horizontally opposed parallel architecture, and the biological phosphorus removal cycle and the biological denitrification cycle are symmetrically arranged and independently regulated, so as to completely solve the "stuck-neck" century problem of the mutual restraint between denitrification and phosphorus removal in the existing biological denitrification and phosphorus removal processes. The technical solution of the present invention can easily realize the function swapping of the anaerobic and anoxic zones, can flexibly switch between preferential denitrification or preferential phosphorus removal, and can also independently regulate the biological denitrification and phosphorus removal effects. The beneficial effects after the implementation of the technical solution of the present invention include, but are not limited to, a reduction of 50% or more in civil engineering investment, a reduction of 30% or more in pipelines, instruments, valves, etc., a reduction of 50% or more in reflux power consumption, a shortening of the process flow by 50% or more, an increase in the sludge concentration in the biological tank by 3 to 5 times, a tolerance to flow impact load of 200 to 300%, an increase in the denitrification and phosphorus removal efficiency by 50% or more, and a reduction of 60% or more in the floor area.

[0016] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0017] A horizontally opposed synchronous biological nitrogen removal and phosphorus removal MBR sewage treatment method, comprising a pretreatment, an anaerobic tank, an anoxic tank, an aerobic membrane tank and a separation zone;

[0018] The pretreatment is located at the front end of the anaerobic tank and the anoxic tank, integrating multiple functions such as sand removal, impurity removal, and floating (suspended) object removal. The interception accuracy is preferably 10-1000μm, and 100-500μm is preferably recommended;

[0019] The pretreatment is equipped with a stepless adjustable water distribution device, which can distribute the pretreated sewage to the anaerobic tank or the anoxic tank at the same time according to the proportion X or Y, and carry out biological denitrification and biological phosphorus removal simultaneously, and X+Y=1;

[0020] The anaerobic tank and the anoxic tank are horizontally placed on both sides of the aerobic membrane tank, and the anaerobic tank and the anoxic tank are not connected to each other but have the same tank capacity;

[0021] The anaerobic tank is connected to the pretreatment zone upstream to receive influent, and is also connected to the separation zone to receive the middle layer sludge; the downstream is connected to the aerobic membrane tank to form a biological phosphorus removal cycle; the HRT of the anaerobic tank is controlled at 1.0~4.0h, preferably 2.0~3.0h is recommended; the ORP is controlled at -150~-350mV, preferably -200~-300mV is recommended; the sludge concentration is controlled at 10~30g / L, preferably 15~25g / L is recommended.

[0022] The anoxic tank is connected to the pretreatment zone upstream to receive the influent, and is also connected to the separation zone to receive the upper reflux nitrification liquid; the downstream is connected to the aerobic membrane tank to form a biological denitrification cycle; the HRT of the anoxic tank is controlled at 1.0~4.0h, preferably 2.0~3.0h is recommended; DO is controlled at 0.01~0.50mg / L, preferably 0.01~0.10mg / L is recommended; sludge concentration is controlled at 10~25g / L, preferably 15~20g / L is recommended.

[0023] The aerobic membrane pool is formed by combining an aerobic pool and a membrane pool. One side receives the upstream anoxic pool for aerobic nitrification, and the other side receives the upstream anaerobic pool for aerobic phosphorus absorption. At the same time, a built-in membrane component is used for filtering and producing water.

[0024] Furthermore, the aerobic membrane pool is filled with a flat-plate, hollow or external membrane assembly, and the flat-plate type is preferably recommended; the membrane assembly is made of CPVC, PTFE, PVDF, etc., and CPVC is preferably recommended;

[0025] Furthermore, the HRT of the aerobic membrane tank is controlled at 4.0 - 8.0 h, preferably 5.0 - 6.0 h; the DO is controlled at 1.0 - 2.0 mg / L, preferably 1.0 - 1.5 mg / L; the sludge concentration is controlled at 10 - 20 g / L, preferably 10 - 15 g / L;

[0026] The upstream of the separation zone is connected to the aerobic membrane tank, and the HRT of the separation zone is controlled at 5 - 30 min, preferably 10 - 15 min; the downstream of the separation zone is connected to the anoxic tank through the reflux of the upper-layer nitrified liquid, and the reflux ratio is controlled at 0 - 600%, preferably 300 - 500%; the downstream of the separation zone is connected to the anaerobic tank through the reflux of the middle-layer sludge, and the reflux ratio is controlled at 0 - 100%, preferably 40 - 80%; the concentration of phosphorus-rich sludge in the lower layer of the separation zone is controlled at 20 - 40 g / L, and is discharged quantitatively in the form of excess sludge to achieve the purpose of biological phosphorus removal, and the sludge discharge amount is determined according to local conditions; the separation zone can be designed as gravity sedimentation or enhanced by an inverted V-shaped short inclined plate, the length of the inclined plate should be 10 - 50 cm, the spacing of the inclined plates should be 5 - 10 cm, the inclination angle of the inclined plate should be 40 - 60°, and the inclined plates should be stacked in 30 - 50 layers;

[0027] Furthermore, the two sets of reflux devices connecting the separation zone with the anaerobic tank and the anoxic tank are arranged on the common wall, that is, the openings (N 1 、N 2 ) of the upper-layer nitrified liquid reflux are 800 - 1000 mm below the liquid level of the separation zone, and the openings (P 1 、P 2 ) of the middle-layer sludge reflux are 600 - 800 mm above the bottom of the separation zone. The two sets of reflux devices are both standard-equipped with frequency converters, and can flexibly switch to operate in the mode of giving priority to biological phosphorus removal or biological nitrogen removal or other modes according to the actual engineering needs.

[0028] Furthermore, the modes include but are not limited to: (1) Linkage pretreatment with stepless adjustable water distribution, N 1 P 1 、N 2 P 2 can easily realize the function swapping of the anaerobic and anoxic zones; (2) Linkage pretreatment with stepless adjustable water distribution, N 1 N 2 、P 1 P 2 can flexibly switch between giving priority to denitrification or giving priority to phosphorus removal; (3) Linkage pretreatment with stepless adjustable water distribution, N 1 P 2 、N 2 P 1 can independently regulate the biological nitrogen and phosphorus removal effects. Description of the Drawings

[0029] The accompanying drawings, which form a part of this specification, are used to further understand the present invention and illustrate the preferred embodiments of the present invention, together with the specification, to explain the principles and structures of the present invention. In the drawings:

[0030] Figure 1 is the schematic diagram of a horizontal opposed type synchronous biological nitrogen and phosphorus removal MBR sewage treatment method of the present invention;

[0031] Figure 2 is the elevation view of a horizontal opposed type synchronous biological nitrogen and phosphorus removal MBR sewage treatment method of the present invention;

[0032] Figure 3 is the 3D view of a horizontal opposed type synchronous biological nitrogen and phosphorus removal MBR sewage treatment method of the present invention;

[0033] The reference numerals in the drawings: 1 is for pretreatment, 2 is the anaerobic tank, 3 is the anoxic tank, 4 is the aerobic membrane tank, 5 is the separation zone, 5.1 is the upper layer reflux nitrified liquid, 5.2 is the middle layer reflux sludge, 5.1 is the lower layer phosphorus-rich sludge, and 6 is the membrane module. Detailed implementation manners

[0034] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the present invention.

[0035] As Figure 1 shown, the influent (i.e., sewage) first passes through the pretreatment 1 to remove impurities such as sand grains, floating objects, and suspended matters to ensure the stable operation of subsequent rotating equipment; the pretreated sewage is divided into two streams. One stream X flows into the anaerobic tank 2 to allow PAOs to fully release phosphorus, then enters the aerobic membrane tank 4 to complete the excessive phosphorus uptake by PAOs, and then flows into the separation zone 5 for liquid-solid separation. The middle layer reflux sludge 5.2 is controlled to flow back to the anaerobic tank 2, while the lower layer phosphorus-rich sludge 5.3 is quantitatively discharged outside in the form of excess sludge, together constituting the biological phosphorus removal cycle, which repeats continuously.

[0036] Synchronously, the other stream Y flows into the anoxic tank 3 to allow the denitrifying bacteria and the upper layer reflux nitrified liquid 5.1 rich in nitrate nitrogen from the separation zone 5 to fully denitrify, then enters the aerobic membrane tank 4 to complete autotrophic nitrification, and then flows into the separation zone 5 to obtain the upper layer reflux nitrified liquid 5.1 rich in nitrate nitrogen through liquid-solid separation, constituting the biological nitrogen removal cycle, which repeats continuously.

[0037] According to Lavoisier's law of conservation of matter, X + Y = 1, where the values of X and Y should be determined by overall calculation based on the influent, effluent, and the goals of biological nitrogen and phosphorus removal.

[0038] The pretreatment 1 integrates multiple functions such as sand removal / impurity removal / floating (suspended) matter removal, including but not limited to ultra-fine gratings, industrial filter cloth, etc., and the recommended interception accuracy is 100 - 500 μm;

[0039] The anaerobic tank 2 and the anoxic tank 3 are horizontally placed opposite to each other on both sides of the aerobic membrane tank 4. The anaerobic tank 2 and the anoxic tank 3 have the same tank volume but are not connected to each other, and cooperate with the reflux in the separation zone 5 to realize the independent regulation of biological phosphorus removal and biological nitrogen removal; the HRT of the anaerobic tank 2 and the anoxic tank 3 is controlled at 2.0 - 3.0 h; the anaerobic tank 2 and the anoxic tank 3 can be separately or combinedly provided with flow guiding walls, agitators, fillers or complete mixing systems.

[0040] It is recommended that the membrane modules 6 in the aerobic membrane tank 4 be filled with CPVC flat plates, the recommended HRT is 5.0 - 6.0 h, the recommended DO control is 1.0 - 1.5 mg / L, and the recommended sludge concentration is 10 - 15 g / L.

[0041] The separation zone 5 is arranged on the downstream side of the aerobic membrane tank 4, the recommended HRT is 10 - 15 min, and the size is coordinated with the overall layout.

[0042] As Figure 2 shown, 2 sets of refluxes are arranged on each of the co - wall sides of the separation zone 5 with the anaerobic tank 2 and the anoxic tank 3, that is, the upper - layer reflux nitrified liquid 5.1 openings (N 1 、N 2 ) are 800 - 1000 mm below the liquid level of the separation zone, and the middle - layer reflux sludge 5.2 openings (P 1 、P 2 ) are 600 - 800 mm above the bottom of the separation zone.

[0043] Furthermore, the 2 sets of refluxes are preferably wall - piercing pumps, both of which are standard - equipped with frequency converters, and according to the actual engineering needs, flexibly switch to operate with biological phosphorus removal priority or biological nitrogen removal priority or other modes. Specifically, the alternative modes include but are not limited to: (1) Linkage pretreatment stepless adjustable water distribution, N 1 P 1 、N 2 P 2 can easily realize the function swapping of the anaerobic and anoxic zones; (2) Linkage pretreatment stepless adjustable water distribution, N 1 N 2 、P 1 P 2 can flexibly switch between nitrogen removal priority and phosphorus removal priority; (3) Linkage pretreatment stepless adjustable water distribution, N 1 P 2 、N 2 P 1 can independently regulate the biological nitrogen removal and phosphorus removal effects.

[0044] Furthermore, the concentration of the phosphorus - rich sludge 5.3 in the lower layer of the separation zone 5 is controlled at 20 - 40 g / L, and is quantitatively discharged in the form of excess sludge to achieve the purpose of biological phosphorus removal, and the sludge discharge amount is determined according to local conditions.

[0045] As Figure 3As shown, pretreatment 1 adopts reinforced concrete, steel structure, brick-concrete and other structural forms. It is recommended to arrange it in two vertical layers. The upper layer is reserved for the installation of the pretreatment host, and the middle layer is reserved for the installation of the filter residue / sand / debris pressing and dehydrating machine to facilitate slag discharge and maintenance.

[0046] The anaerobic tank 2, the anoxic tank 3, the aerobic membrane tank 4, and the separation zone 5 can all be made of reinforced concrete, steel structure, brick-concrete, etc. If there is a need for upstream and downstream connection, the common wall design is preferred to save civil engineering investment.

[0047] The present embodiment discloses a horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method, which adopts a horizontally opposed parallel architecture design, integrates the advantages of MBR forced screening and domestication of denitrification and phosphorus removal bacteria, abandons the defects of separate MBR aerobic tanks and membrane tanks, and enables the high flexibility of independent regulation of the biological denitrification cycle and the biological phosphorus removal cycle in the core of the AAO process, meeting many realistic and urgent rigid demands such as deep pollution reduction and carbon reduction, precise cost control and efficiency improvement, in-situ quality improvement and capacity expansion, and flexible operation and maintenance customization, with huge application potential, broad market prospects, and excellent environmental, social and economic benefits.

[0048] In extreme cases, the aerobic membrane tank described in the present invention can be replaced by a combination of "aerobic tank + sedimentation tank". However, as long as the aerobic tank is directly coupled with the anaerobic tank and the anoxic tank, the horizontally opposed parallel architecture design can achieve a certain degree of automatic synchronization, function switching and independent regulation of biological denitrification and phosphorus removal, and to some extent alleviate the century-old problem of mutual restraint between denitrification and phosphorus removal in the existing biological denitrification and phosphorus removal process. Although the use of MBR is not involved at this time, it can still be regarded as a specific derivative variant within the spirit and principle of the present invention.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method, which adopts a horizontally opposed parallel architecture design to achieve automatic synchronization, function switching and independent regulation of biological denitrification and phosphorus removal, characterized in that: After pre-treatment, the sewage is filtered to remove impurities such as sand and suspended matter, and then enters the anaerobic tank and the anoxic tank in proportion. The anaerobic tank is directly coupled with the aerobic membrane tank to form a biological phosphorus removal cycle, and the anoxic tank is directly coupled with the aerobic membrane tank to form a biological denitrification cycle. The membrane components are filled in the aerobic membrane tank, and the downstream side of the aerobic membrane tank is connected to the separation zone through the same wall. The separation zone is equipped with an upper layer reflux nitrification liquid reflux, a middle layer sludge reflux, and a lower layer phosphorus-rich sludge fixed discharge system.

2. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The pretreatment is located at the front end of the anaerobic tank and the anoxic tank, integrating multiple functions such as sand removal / impurity removal / floating (suspended) floating matter removal, and the interception accuracy is preferably 10~1000μm, preferably 100~500μm; the pretreatment is equipped with a stepless adjustable water distribution device as standard, which can distribute the pretreated sewage to the anaerobic tank or the anoxic tank at the same time according to the proportion X or Y, X+Y=1.

3. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The upstream of the anaerobic tank is connected to the pretreated influent and the sludge return in the middle layer of the separation zone; the downstream is connected to the aerobic membrane tank to form a biological phosphorus removal cycle; the HRT of the anaerobic tank is controlled at 1.0~4.0h, preferably 2.0~3.0h is recommended; the ORP is controlled at -150~-350mV, preferably -200~-300mV is recommended; the sludge concentration is controlled at 10~30g / L, preferably 15~25g / L is recommended.

4. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The upstream of the anoxic pool is connected to the pretreated influent and the nitrified liquid reflux in the upper layer of the separation zone; The downstream is connected to the aerobic membrane tank to form a biological denitrification cycle; the HRT of the anoxic tank is controlled at 1.0~4.0h, preferably 2.0~3.0h is recommended; DO is controlled at 0.01~0.50mg / L, preferably 0.01~0.10mg / L is recommended; sludge concentration is controlled at 10~25g / L, preferably 15~20g / L is recommended.

5. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The aerobic membrane pool is formed by merging an aerobic pool and a membrane pool, and its three major functions are complete nitrification, deep phosphorus absorption and filtered water production, that is, it is connected to the upstream anoxic pool to complete aerobic nitrification, connected to the upstream anaerobic pool to complete aerobic phosphorus absorption, and the built-in membrane component completes filtration and water production; the membrane component is of flat plate type, hollow type or external type, and the flat plate type is preferably recommended; the material of the membrane component is CPVC, PTFE, PVDF, etc., and CPVC is preferably recommended; the HRT of the aerobic membrane pool is controlled at 4.0~8.0h, and 5.0~6.0h is preferably recommended; DO is controlled at 1.0~2.0mg / L, and 1.0~1.5mg / L is preferably recommended; the sludge concentration is controlled at 10~20g / L, and 10~15g / L is preferably recommended.

6. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The separation zone receives fresh aerobic sludge flowing from the aerobic membrane pool and divides it into three parts: the upper layer of reflux nitrification liquid, the middle layer of reflux sludge, and the lower layer of phosphorus-rich sludge, and annihilates DO at the same time; the upstream of the separation zone is connected to the aerobic membrane pool, and the HRT of the separation zone is controlled at 5~30min, preferably 10~15min is recommended; the downstream of the separation zone is connected to the anoxic pool through the reflux nitrification liquid of the upper layer, and the reflux ratio is controlled at 0~600%, preferably 300~500% is recommended; the downstream of the separation zone is connected to the anoxic pool through the reflux nitrification liquid of the upper layer, and the reflux ratio is controlled at 0~600%, preferably 300~500% is recommended; The middle layer sludge return is connected to the anaerobic tank, and the return ratio is controlled at 0-100%, preferably 40-80% is recommended; the concentration of phosphorus-rich sludge in the lower layer of the separation zone is controlled at 20-40 g / L, and is quantitatively discharged in the form of residual sludge to achieve the purpose of biological phosphorus removal, and the amount of sludge discharged is determined according to local conditions; the separation zone can be designed as gravity sedimentation or inverted V-shaped short inclined plate reinforcement, the inclined plate length is preferably 10-50 cm, the inclined plate spacing is preferably 5-10 cm, the inclined plate inclination angle is preferably 40-60°, and the inclined plate stacking is preferably 30-50 layers.

7. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The anaerobic tank and the anoxic tank are horizontally arranged on both sides of the aerobic membrane tank. The anaerobic tank and the anoxic tank are not connected to each other but have the same tank capacity. The anaerobic tank, the anoxic tank and the aerobic membrane tank can be provided with guide walls, flow pushers, biological fillers or complete mixing devices separately or in combination.

8. A horizontally opposed synchronous biological denitrification and phosphorus removal MBR sewage treatment method according to claim 1, characterized in that: The two sets of reflux devices connected to the separation zone and the anaerobic tank and the anoxic tank are arranged on the same wall, that is, the upper reflux nitrification liquid opening (N1, N2) is 800~1000mm below the liquid level of the separation zone, and the middle sludge reflux opening (P1, P2) is 600~800mm above the bottom of the separation zone; the two sets of reflux devices are both equipped with frequency converters as standard, which can flexibly switch between biological phosphorus removal priority, biological denitrification priority or other operation modes according to actual project needs; specifically, the modes include but are not limited to (1) linked pretreatment stepless adjustable water distribution, N1P1 and N2P2 can realize the function swap of anaerobic and anoxic zones; (2) linked pretreatment stepless adjustable water distribution, N1N2 and P1P2 can switch between denitrification priority and phosphorus removal priority; (3) linked pretreatment stepless adjustable water distribution, N1P2 and N2P1 can independently regulate the biological denitrification and phosphorus removal effects.

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