Bioreactor based on denitrifying phosphorus removal and synchronous nitrogen and phosphorus removal process for sewage

Abstract

The invention discloses a denitrification phosphorus removal-based bioreactor and a synchronous sewage nitrogen and phosphorus removal process, and belongs to the technical field of sewage treatment, the denitrification phosphorus removal-based bioreactor comprises an anaerobic tank, two sequencing batch tanks, two adjusting tanks, an aerobic tank and an anoxic tank; the anaerobic tank is used for receiving the to-be-treated sewage and the activated sludge refluxed by the adjusting tank and carrying out an anaerobic phosphorus release process under the action of the activated sludge; the sequencing batch tanks are used for receiving treatment liquid of the anaerobic tank and reflux liquid of the aerobic tank and carrying out anoxic denitrification reaction under a water inlet condition, a stirring condition and a pre-precipitation condition, and the two sequencing batch tanks are connected in parallel to carry out multi-cycle alternate reaction; the two adjusting pools are respectively connected in series with different sequencing batch pools; the aerobic tank is used for receiving liquid discharged from the sequencing batch tank and / or the adjusting tank and carrying out aerobic carbonization and / or nitration reaction; the anoxic tank is used for receiving treatment liquid of the aerobic tank and carrying out a denitrifying phosphorus removal process; the synchronous sewage nitrogen and phosphorus removal process based on the denitrifying phosphorus removal bioreactor can realize full nitrification of ammonia nitrogen in the sewage, and the total nitrogen removal efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a bioreactor based on denitrification and phosphorus removal and a sewage simultaneous nitrogen and phosphorus removal process. Background Art

[0002] AAO (Anaerobic-Anoxic-Oxic) process is a secondary sewage treatment process commonly used in urban sewage treatment plants, but there are problems of sludge age conflict and carbon source competition, and the cost of treating low carbon-nitrogen ratio wastewater is high. Denitrification phosphorus removal technology cultivates polyphosphate bacteria (DPAOs) in an anaerobic / anoxic environment. DPAOs carry out different physiological activities in the anaerobic and anoxic stages, absorb phosphates in sewage, and reduce nitrates at the same time, thereby achieving the purpose of simultaneous nitrogen and phosphorus removal, reducing carbon source demand (one carbon dual use), and is suitable for low C / N ratio sewage, with broad prospects.

[0003] Denitrifying phosphorus removal processes are mainly divided into two categories: single sludge process and double sludge process. In the single sludge system, taking the BCFS process as an example, DPAOs and nitrifying bacteria coexist in the same system. However, due to the setting of system parameters, it is difficult to take into account the optimal growth conditions of both, and it is also impossible to solve the contradiction between carbon sources and sludge ages between different bacterial communities. In contrast, a more optimized solution is the double sludge process. The double sludge system achieves effective separation of DPAOs and nitrifying bacteria by placing them in independent reaction units. Typical examples of this type of process include the Dephanox process and the A2N-SBR process. Laboratory studies have shown that the Dephanox process and the A2N-SBR process can achieve good phosphorus and nitrogen removal effects, but if the above processes are to be put into actual production operation, there are still some shortcomings, mainly manifested in the high ammonia nitrogen concentration of the effluent, the low total nitrogen removal rate, and the stability of the process is easily affected by water quality. In the Dephanox process, ammonia nitrogen that exceeds the sludge load is not nitrified; in the A2N-SBR process, the volume exchange of the A2SBR pool is generally only 50% to 70%, and the ammonia nitrogen in the remaining pool volume cannot be nitrified; the double sludge denitrification phosphorus removal system disclosed in the Chinese patent document with publication number CN10600725A also has the problem of some wastewater not being nitrified during the reactor reversing flow process, which leads to a high ammonia nitrogen concentration in the corresponding process effluent, thereby affecting the removal effect of total nitrogen.

[0004] In addition, the operational stability of the denitrification phosphorus removal process mainly depends on whether the nitrogen and phosphorus concentration ratios in the influent water quality match. However, in practice, the influent water quality is in a fluctuating state. When the nitrate concentration is low, the phosphorus absorption will be limited due to insufficient electron acceptors; if the nitrate is excessive, it will affect the phosphorus release in the circulating sludge or the anaerobic stage of the next process sludge, and the excess nitrate itself also means a low total nitrogen removal rate.

[0005] In view of the above problems, the present invention proposes a bioreactor based on denitrification and phosphorus removal and a wastewater simultaneous denitrification and phosphorus removal process, which fully utilizes the advantages of denitrification and phosphorus removal and is suitable for actual production applications. Summary of the invention

[0006] In order to give full play to the advantages of the double sludge denitrification phosphorus removal process and solve the shortcomings of the above-mentioned prior art, the present invention provides a bioreactor based on denitrification phosphorus removal, which can achieve full nitrification of ammonia nitrogen in sewage and improve the total nitrogen removal efficiency.

[0007] The specific technical solutions adopted are as follows:

[0008] A bioreactor based on denitrification and phosphorus removal, comprising an anaerobic tank, two sequencing batch tanks, two adjustment tanks, an aerobic tank and an anoxic tank;

[0009] The anaerobic tank is used to receive the sewage to be treated and the activated sludge returned from the adjustment tank. The anaerobic phosphorus release process under the action of the activated sludge is carried out in the anaerobic tank, and the treated liquid in the anaerobic tank is input into different batch tanks.

[0010] The sequencing batch tank is used to receive the treated liquid from the anaerobic tank and the return liquid from the aerobic tank and to carry out anoxic denitrification reaction under water inlet conditions, stirring conditions and pre-precipitation conditions therein; wherein, two sequencing batch tanks are connected in parallel to carry out multi-cycle alternating reactions; in the first half of a reaction cycle, one sequencing batch tank receives the treated liquid from the anaerobic tank and the return liquid from the aerobic tank and carries out anoxic denitrification reaction under water inlet conditions, and at the same time, the supernatant after the treatment of the previous cycle is discharged into the aerobic tank, and the remaining treated liquid enters the corresponding adjustment tank; at the same time, the connecting parts between the other sequencing batch tank and the anaerobic tank and the aerobic tank are all in a closed state, and anoxic denitrification under stirring conditions and pre-precipitation conditions are carried out in the sequencing batch tank in turn. reaction; in the second half of a reaction cycle, the operation and functions of the two batch pools are interchanged (the connecting parts between the batch pool that has carried out anoxic denitrification reaction under the influent condition in the first half of the cycle and the anaerobic pool and the aerobic pool are closed, and anoxic denitrification reaction under stirring conditions and pre-precipitation conditions is carried out in the batch pool in turn. At the same time, the connecting parts between the other batch pool and the anaerobic pool and the aerobic pool are opened to receive the treated liquid from the anaerobic pool and the reflux liquid from the aerobic pool, and carry out anoxic denitrification reaction under the influent condition. At the same time, the supernatant after the treatment in the previous cycle is discharged into the aerobic pool, and the remaining treated liquid enters the corresponding adjustment pool); after a reaction cycle ends, the cycle enters the next reaction cycle;

[0011] The two adjustment tanks are connected in series with different sequencing batch tanks respectively. The adjustment tank and the sequencing batch tank are always connected. The activated sludge in the adjustment tank is returned to the anaerobic tank, and the supernatant is discharged into the aerobic tank.

[0012] The aerobic tank is used to receive the effluent from the sequencing batch tank and / or the adjustment tank, and aerobic carbonization and / or nitrification reactions are carried out in the aerobic tank;

[0013] The anoxic tank is used to receive the treated liquid from the aerobic tank, and further denitrification and denitrification process is carried out in the anoxic tank.

[0014] Specifically, the sewage or treated liquid in the anaerobic tank, sequencing batch tank and adjustment tank of the bioreactor based on denitrification phosphorus removal contains activated sludge, and the activated sludge is circulated and transferred among the anaerobic tank, sequencing batch tank and adjustment tank along with the sewage or treated liquid; after the activated sludge undergoes adsorption and phosphorus release reaction under anaerobic conditions, it is mixed with the return liquid from the aerobic tank in the sequencing batch tank, and the return liquid contains nitrate nitrogen, then anoxic denitrification phosphorus removal process can be carried out in the sequencing batch tank under anoxic conditions.

[0015] Preferably, the bioreactor based on denitrification and phosphorus removal is an integrated box structure, the treatment pools are connected by connecting valves, connecting pipes or water distribution systems, and the adjacent treatment pools share the same wall panels.

[0016] The anaerobic tank outlet side is fed into different batch tanks through a thin-wall weir-type outlet water distribution device (structure reference Chinese patent document with publication number CN118791128A), and there is a liquid level difference between the anaerobic tank and the batch tank.

[0017] Furthermore, when the sequencing batch tank carries out anoxic denitrification reaction under stirring conditions or pre-sedimentation conditions, the connecting components between the sequencing batch tank and the anaerobic tank and the aerobic tank are all in a closed state, and the connecting components between the adjustment tank corresponding to the sequencing batch tank and the anaerobic tank and the aerobic tank are also in a closed state.

[0018] Furthermore, a stirring device is installed in the anaerobic tank and the sequencing batch tank; a stirring device and an aeration device are installed in the adjustment tank. The setting of the stirring device and the aeration device enables the reaction in the adjustment tank to be carried out under aeration conditions, stirring conditions or static conditions.

[0019] Preferably, the bottom surface of the sequencing batch tank is rectangular, and the aspect ratio is further preferably 2-4:1. The sequencing batch tank is connected to the bottom of the adjustment tank, and the adjustment tank is arranged on the outlet side of the sequencing batch tank. The overall plane shape of the sequencing batch tank and the adjustment tank is rectangular, and the aspect ratio is further preferably 3-5:1. The beneficial effect of the above arrangement is that the treated liquid in the sequencing batch tank can maintain the reaction during the process of moving from the water inlet to the water outlet, and the horizontal sedimentation effect causes the activated sludge to precipitate and obtain the supernatant at the outlet, which can ensure that the supernatant entering the aerobic tank contains less activated sludge. In order to improve the sedimentation effect, a shallow sedimentation facility with an inclined plate can also be added to the tank.

[0020] Furthermore, the aerobic pool is provided with biological fillers on which microbial membranes are cultured, and the microorganisms perform aerobic carbonization and / or nitrification reactions in the aerobic pool.

[0021] Furthermore, a biological filler is provided in the anoxic tank, on which a microbial membrane is cultured, and the microorganisms perform anoxic denitrification reaction in the anoxic tank.

[0022] Furthermore, sludge discharge devices are provided in the adjustment tank, aerobic tank and anoxic tank to discharge the residual sludge and detached biofilm from the system.

[0023] The present invention also provides a wastewater simultaneous denitrification and dephosphorization process, wherein the wastewater to be treated is input into the bioreactor based on denitrification and dephosphorization to perform simultaneous denitrification and dephosphorization treatment on the wastewater.

[0024] Specifically, the bioreactor based on denitrification and phosphorus removal has been subjected to sludge acclimatization and preliminary debugging before being put into use, and can be used to directly carry out a multi-cycle alternating reaction process. The process includes:

[0025] (1) The sewage to be treated is input into the anaerobic tank and mixed with the activated sludge returned from the adjustment tank to perform anaerobic phosphorus release reaction under anaerobic conditions;

[0026] (2) mixing the anaerobic tank treated liquid obtained in step (1) with the aerobic tank return liquid and inputting them into different sequencing batch tanks for multiple cycles of alternating reactions. In the first half of a reaction cycle, the connecting parts between a sequencing batch tank and the anaerobic tank and the aerobic tank are opened, and the sequencing batch tank is always connected to the adjustment tank. After receiving the anaerobic tank treated liquid and the aerobic tank return liquid, an anaerobic denitrification reaction is carried out under water inlet conditions, and the original supernatant in the sequencing batch tank is discharged into the aerobic tank, and the remaining liquid enters the adjustment tank corresponding to the sequencing batch tank. At the same time, the connecting parts between another sequencing batch tank and the anaerobic tank and the aerobic tank are closed, and the connecting parts between the adjustment tank corresponding to the sequencing batch tank and the anaerobic tank are closed. The sequencing batch tank is always connected to the adjustment tank, and the original anaerobic tank treated liquid and the aerobic tank return liquid in the sequencing batch tank are subjected to an anaerobic denitrification reaction under stirring conditions and pre-precipitation conditions in turn. After the second half of a reaction cycle, the operation and functions of the two sequencing batch tanks are interchanged; after the end of a reaction cycle, the cycle enters the next reaction cycle;

[0027] (3) When anoxic denitrification reaction is carried out under water inlet conditions in the sequencing batch tank corresponding to the adjustment tank, the aeration device and the stirring device in the adjustment tank are both in a closed state, and the adjustment tank further processes the received liquid, so that the activated sludge is returned to the anaerobic tank, and the supernatant is discharged into the aerobic tank; when anoxic denitrification reaction is carried out under stirring conditions and pre-precipitation conditions in the sequencing batch tank corresponding to the adjustment tank, the aeration device is turned on / off, and / or the stirring device is turned on / off, and / or a carbon source is added to react according to the components of the received liquid in the adjustment tank;

[0028] (4) subjecting the supernatant discharged into the aerobic tank in step (2) or step (3) to aerobic carbonization and / or nitrification under the action of an aerobic biofilm;

[0029] (5) discharging the treated liquid from the aerobic tank in step (4) into the anoxic tank to further undergo a denitrification process;

[0030] (6) The treated liquid from the anoxic tank in step (5) is discharged into a high-efficiency sedimentation tank to further remove total phosphorus and suspended solids, thereby completing the simultaneous denitrification and dephosphorization process for sewage.

[0031] Furthermore, in the process of simultaneous denitrification and phosphorus removal in sewage, the dissolved oxygen in the anaerobic tank is controlled to be less than 0.2 mg / L, the redox potential ORP is controlled to be less than -200 mV, the dissolved oxygen in the sequencing batch tank is controlled to be less than 0.5 mg / L, the dissolved oxygen in the aerobic tank is controlled to be 2-4 mg / L, and the dissolved oxygen in the anoxic tank is controlled to be less than 0.5 mg / L.

[0032] Preferably, stirring or aeration or addition of a carbon source reaction is performed in the adjustment tank according to the components of the received liquid; when the total phosphorus in the influent of the adjustment tank is greater than 0.5 mg / L and the nitrate nitrogen content is less than 3 mg / L, the aeration device of the adjustment tank is turned on and the dissolved oxygen is controlled, and the dissolved oxygen provided by the aeration process is used as an electron acceptor to enhance the removal of total phosphorus; when the nitrate nitrogen content in the influent of the adjustment tank is greater than 5 mg / L, the stirring device of the adjustment tank is turned on, and a carbon source is added to the adjustment tank to enhance the removal of total nitrogen; under other conditions, the aeration device and stirring device of the adjustment tank are in a closed state to further precipitate the activated sludge and increase the activated sludge content in the reflux liquid.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) Comparison of Delphanox and A 2 N process, the sewage simultaneous denitrification and phosphorus removal process using the bioreactor based on denitrification and phosphorus removal provided by the present invention can achieve full nitrification of ammonia nitrogen in sewage and improve the total nitrogen removal efficiency.

[0035] (2) The bioreactor and sewage simultaneous denitrification and phosphorus removal process of the present invention removes nitrogen and phosphorus from sewage through the denitrification and phosphorus removal mechanism. Compared with the traditional denitrification and phosphorus removal process, it can save the amount of carbon source supplement, save about 30% of aeration volume, and reduce the amount of residual sludge by about 50%. It is suitable for the treatment of urban sewage and industrial wastewater that require denitrification and phosphorus removal.

[0036] (3) The process for simultaneous denitrification and phosphorus removal from sewage of the present invention combines an activated sludge method with a biofilm method. The activated sludge and the biofilm do not interfere with each other. Denitrifying bacteria and nitrifying bacteria are cultured separately, which can quickly enrich denitrifying and phosphorus removal bacteria and avoid sludge age conflicts. At the same time, the bioreactor of the present invention uses a sequencing batch tank as a reaction tank for denitrification and phosphorus removal and a sludge pre-sedimentation tank, so that one tank can be used for two purposes.

[0037] (4) Through the design of the present invention, the adjustment tank can operate the reaction under three conditions, with high nitrogen and phosphorus removal efficiency, avoiding the imbalance of nitrogen and phosphorus ratio affecting the treatment effect, and further post-denitrification through the anoxic tank biofilm denitrification method to improve efficiency. The sewage treated by the bioreactor of the present invention has less suspended solids, and there is no need for secondary sedimentation treatment and sludge return of the traditional process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the planar structure of the bioreactor based on denitrification and phosphorus removal in the present invention.

[0039] Figure 2 It is another cross-sectional structural schematic diagram of the bioreactor based on denitrification and phosphorus removal in the present invention.

[0040] Figure 3 It is a flow chart of the process for simultaneous nitrogen and phosphorus removal from sewage in the present invention.

[0041] Among them: 1 anaerobic tank; 21 first batch tank, 22 second batch tank, 31 first adjusting tank, 32 second adjusting tank, 4 aerobic tank, 5 anoxic tank, 6 stirring device, 7 channel water distribution system, 81 first outlet pipe system, 82 second outlet pipe system, 91 first valve, 92 second valve, 101 first adjusting tank return pump, 102 second adjusting tank return pump, 11 biological filler, 12 aeration device, 131 first aerobic tank return pump, 132 second aerobic tank return pump, 14 adjustable weir gate. DETAILED DESCRIPTION

[0042] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description through specific embodiments. In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below. The technical features in each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0043] The operating methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. The contents not described in detail in this specification belong to the prior art known to professionals in the field. The experimental materials used in the following examples, unless otherwise specified, can be purchased from conventional biochemical reagent companies.

[0044] Example 1

[0045] Specifically, a bioreactor based on denitrification and phosphorus removal is an integrated box structure, wherein each treatment tank is connected by a connecting valve, a connecting pipe or a water distribution system, and adjacent treatment tanks share a wall plate, specifically including an anaerobic tank 1, a first batch tank 21, a second batch tank 22, a first adjustment tank 31, a second adjustment tank 32, an aerobic tank 4, and an anoxic tank 5;

[0046] In this embodiment, the approximate volume ratio of the anaerobic tank 1, the first batch tank 21, the second batch tank 22, the first adjustment tank 31, the second adjustment tank 32, the aerobic tank 4, and the anoxic tank 5 is 1:5:5:1:1:4.5:0.5.

[0047] like Figure 1 and Figure 2 As shown, the outlet of the anaerobic tank 1 is connected to the water inlet of the first batch tank 21 and the second batch tank 22 through a water channel water distribution system 7 (preferably a thin-walled weir type water outlet distribution device), the outlet of the first batch tank 21 is connected to the water inlet of the first adjustment tank 31, and a first adjustment tank return pump 101 is provided in the first adjustment tank 31. The first adjustment tank return pump 101 is used to return the activated sludge to the anaerobic tank 1, the outlet of the first adjustment tank 31 is connected to the water inlet of the aerobic tank 4, the outlet of the second batch tank 22 is connected to the water inlet of the second adjustment tank 32, and the second adjustment tank 32 is connected to the water outlet of the first adjustment tank 31. A second adjusting tank return pump 102 is provided, and the second adjusting tank return pump 102 is used for returning the activated sludge to the anaerobic tank 1. The outlet of the second adjusting tank 32 is connected to the inlet of the aerobic tank 4. The first aerobic tank return pump 131 and the second aerobic tank return pump 132 are provided in the aerobic tank 4. The first aerobic tank return pump 131 returns the aerobic tank return liquid to the first batch tank 21, and the second aerobic tank return pump 132 returns the aerobic tank return liquid to the second batch tank 22. The outlet of the aerobic tank 4 is connected to the inlet of the anoxic tank 5, and the treated liquid in the anoxic tank 5 is output through the adjustable weir gate 14.

[0048] The anaerobic tank 1 is used to receive the sewage to be treated, and a stirring device 6 is installed in the anaerobic tank 1; it is also used to receive the activated sludge returned from the adjustment tank, and the anaerobic phosphorus release process under the action of the activated sludge is carried out in the anaerobic tank, and the anaerobic tank treatment liquid is input into the first batch tank 21 and the second batch tank 22;

[0049] The sequencing batch tank is used to receive the treated liquid from the anaerobic tank and the return liquid from the aerobic tank and to carry out anoxic denitrification reaction under water inlet conditions, stirring conditions and pre-precipitation conditions therein; wherein, two sequencing batch tanks are connected in parallel to carry out multi-cycle alternating reactions; in the first half of a reaction cycle, the first sequencing batch tank 21 receives the treated liquid from the anaerobic tank and the return liquid from the aerobic tank, and carries out anoxic denitrification reaction under water inlet conditions, and at the same time, the supernatant after the treatment of the previous cycle is discharged into the aerobic tank, and the remaining treated liquid enters the first adjustment tank 31, and at the same time, the connecting parts between the second sequencing batch tank 22 and the anaerobic tank 1 and the aerobic tank 4 are all in a closed state, and stirring is carried out in sequence inside the sequencing batch tanks. anoxic denitrification reaction under stirring conditions and pre-precipitation conditions; in the second half of a reaction cycle, the connecting parts between the first batch pool 21 and the anaerobic pool 1 and the aerobic pool 4 are closed, and anoxic denitrification reaction under stirring conditions and pre-precipitation conditions is carried out in the batch pool in turn. At the same time, the connecting parts between the second batch pool 22 and the anaerobic pool 1 and the aerobic pool 4 are opened to receive the anaerobic pool treated liquid and the aerobic pool return liquid, and anoxic denitrification reaction is carried out under water inlet conditions. At the same time, the supernatant after the previous cycle is discharged into the aerobic pool 4, and the remaining treated liquid enters the second adjustment pool 32; after a reaction cycle ends, the cycle enters the next reaction cycle;

[0050] The first adjusting tank 31 and the first sequencing batch tank 21 are connected in series and are always connected, the second adjusting tank 32 and the second sequencing batch tank 22 are connected in series and are always connected, the activated sludge in the adjusting tank is returned to the anaerobic tank 1, and the supernatant is discharged into the aerobic tank 4; the first adjusting tank 31, the first sequencing batch tank 21, the second adjusting tank 32 and the second sequencing batch tank 22 are equipped with a stirring device 6, and the first adjusting tank 31 and the second adjusting tank 32 are equipped with an aeration device 12.

[0051] The aerobic tank 4 is used to receive the effluent from the first batch tank 21, the second batch tank 22, the first adjustment tank 31 and the second adjustment tank 32. The aerobic tank is provided with a biological filler 11 on which a microbial film is cultured. The microorganisms perform aerobic carbonization and / or nitrification reactions in the aerobic tank. The aerobic tank 4 is also provided with a sludge discharge device.

[0052] The anoxic pool 5 is used to receive the treated liquid from the aerobic pool. The anoxic pool 5 is provided with a biological filler 11 on which a microbial film is cultured. The microorganisms perform anoxic denitrification reaction in the anoxic pool. The anoxic pool 5 is also provided with a sludge discharge device.

[0053] Furthermore, the wastewater to be treated is input into the above-mentioned bioreactor based on denitrification and phosphorus removal to carry out a wastewater simultaneous nitrogen and phosphorus removal process. The flow chart is as follows: Figure 3 As shown;

[0054] The first half of a reaction cycle:

[0055] First, the sewage to be treated enters the anaerobic tank, and at the same time, the activated sludge returned from the first adjustment tank 31 is returned to the anaerobic tank 1 through the first adjustment tank return pump 101, and anaerobic adsorption of organic matter and phosphorus release reaction are carried out in the anaerobic tank 1. Then, the anaerobic tank treatment liquid enters the first batch tank 21, and at the same time, the aerobic tank treatment liquid enters the first batch tank 21 through the first aerobic tank return pump 131, and anoxic denitrification and phosphorus removal reaction occurs under the water inlet conditions. While the liquid is entering, the first batch tank 21 is automatically treated by the liquid from the previous batch reaction. The liquid flows into the first adjustment tank 31, and after the reaction in the first adjustment tank 31, it enters the anaerobic tank 1 for circulation through the first adjustment tank return pump 101. According to the water quality and operation conditions in the first adjustment tank 31, anoxic reaction under stirring conditions or anoxic reaction under aeration conditions or standing is selected, and at the same time, the supernatant of the treated liquid after the previous batch reaction is discharged into the aerobic tank 4 through the first outlet pipe system 81; aerobic carbonization and nitrification reactions occur in the aerobic tank 4, and the aerobic tank treated liquid enters the anoxic tank 5 for anoxic denitrification reaction. At this time, the second batch tank 22 in the opposite direction first performs anoxic denitrification phosphorus removal process under stirring conditions, and then performs a pre-precipitation process and anoxic reaction in the pre-precipitation process, and its second outlet pipe system 82 and second valve 92 are closed, and the second adjustment tank return pump 102 in the second adjustment tank 32 and the second aerobic tank return pump 132 in the aerobic tank 4 are closed.

[0056] The second half of a reaction cycle:

[0057] The operations of the first batch tank 21, the first outlet pipe system 81, the first valve 91, the first adjusting tank return pump 101, the first aerobic tank return pump 131 and the second batch tank 22, the second outlet pipe system 82, the second valve 92, the second adjusting tank return pump 102, the second aerobic tank return pump 132 are interchanged, and the cycle is repeated continuously to treat sewage.

[0058] The specific process is as follows:

[0059] (1) The sewage to be treated is input into the anaerobic tank and mixed with the activated sludge returned from the adjustment tank to perform anaerobic phosphorus release reaction under anaerobic conditions;

[0060] (2) mixing the anaerobic tank treated liquid obtained in step (1) with the aerobic tank return liquid and inputting them into different sequencing batch tanks for multiple cycles of alternating reactions. In the first half of a reaction cycle, the connecting parts between a sequencing batch tank and the anaerobic tank and the aerobic tank are opened, and the sequencing batch tank is always connected to the adjustment tank. After receiving the anaerobic tank treated liquid and the aerobic tank return liquid, an anaerobic denitrification reaction is carried out under water inlet conditions, and the original supernatant in the sequencing batch tank is discharged into the aerobic tank, and the remaining liquid enters the adjustment tank corresponding to the sequencing batch tank. At the same time, the connecting parts between another sequencing batch tank and the anaerobic tank and the aerobic tank are closed, and the connecting parts between the adjustment tank corresponding to the sequencing batch tank and the anaerobic tank are closed. The sequencing batch tank is always connected to the adjustment tank, and the original anaerobic tank treated liquid and the aerobic tank return liquid in the sequencing batch tank are subjected to an anaerobic denitrification reaction under stirring conditions and pre-precipitation conditions in turn. After the second half of a reaction cycle, the operation and functions of the two sequencing batch tanks are interchanged; after the end of a reaction cycle, the cycle enters the next reaction cycle;

[0061] (3) When anoxic denitrification reaction is carried out under water inlet conditions in the sequencing batch tank corresponding to the adjustment tank, the aeration device and the stirring device in the adjustment tank are both in a closed state, and the adjustment tank further processes the received liquid, so that the activated sludge is returned to the anaerobic tank, and the supernatant is discharged into the aerobic tank; when anoxic denitrification reaction is carried out under stirring conditions and pre-precipitation conditions in the sequencing batch tank corresponding to the adjustment tank, the aeration device is turned on / off, and / or the stirring device is turned on / off, and / or a carbon source is added to react according to the components of the received liquid in the adjustment tank;

[0062] (4) subjecting the supernatant discharged into the aerobic tank in step (2) or step (3) to aerobic carbonization and / or nitrification under the action of an aerobic biofilm;

[0063] (5) discharging the treated liquid from the aerobic tank in step (4) into the anoxic tank to further undergo a denitrification process;

[0064] (6) The treated liquid from the anoxic tank in step (5) is discharged into a high-efficiency sedimentation tank to further remove total phosphorus and suspended solids, thereby completing the simultaneous denitrification and dephosphorization process for sewage.

[0065] Furthermore, in the process of simultaneous denitrification and phosphorus removal in sewage, the dissolved oxygen in the anaerobic tank is controlled to be less than 0.2 mg / L, the redox potential ORP is controlled to be less than -200 mV, the dissolved oxygen in the sequencing batch tank is controlled to be less than 0.5 mg / L, the dissolved oxygen in the aerobic tank is controlled to be 2-4 mg / L, and the dissolved oxygen in the anoxic tank is controlled to be less than 0.5 mg / L.

[0066] Furthermore, the adjustment tank is stirred or aerated or a carbon source is added for reaction according to the components of the received liquid; when the total phosphorus in the influent of the adjustment tank is greater than 0.5 mg / L and the nitrate nitrogen content is less than 3 mg / L, the aeration device of the adjustment tank is turned on and the dissolved oxygen is controlled, and the dissolved oxygen provided by the aeration process is used as an electron acceptor to enhance the effect of removing total phosphorus; when the nitrate nitrogen content in the influent of the adjustment tank is greater than 5 mg / L, the stirring device of the adjustment tank is turned on, and a carbon source is added to the adjustment tank to enhance the effect of removing total nitrogen; under other conditions, the aeration device and stirring device of the adjustment tank are in a closed state to further precipitate the activated sludge and increase the activated sludge content in the return liquid.

[0067] Example 2

[0068] As an example, the bioreactor based on denitrification and phosphorus removal in this embodiment is 6.6m long, 4.8m wide, and 3m high, and the daily sewage treatment capacity is 100m 3 . The sewage is municipal sewage, including some industrial wastewater, which needs to be denitrified and dephosphorized. The water quality fluctuates greatly. The AO process needs to add carbon source to meet the standard. The A2N-SBR process will exceed the standard for ammonia nitrogen and total nitrogen. The cycle operation of the bioreactor based on denitrification and phosphorus removal in this embodiment is shown in Table 1. The reflux rate in the oxidation tank is set to 200%, and the reflux rate in the adjustment tank is set to 50%.

[0069] Table 1 Operation status of main unit equipment during the operation cycle

[0070]

[0071] After the sewage was treated through the above cycles, the results were shown in Table 2, indicating that the reactor in the embodiment can efficiently remove nitrogen and phosphorus from the sewage.

[0072] Table 2 Water quality before and after sewage treatment in Example 2

[0073]

[0074] Example 3

[0075] As an example, the bioreactor based on denitrification and phosphorus removal in this embodiment is 6.6m long, 4.8m wide, and 3m high, and the daily sewage treatment capacity is 80m 3 The sewage is a mixture of municipal sewage and printing industry wastewater, which needs to be denitrified and dephosphorized. The cycle operation of the reactor in this embodiment is shown in Table 3. The reflux rate in the oxidation tank is set to 200%, and the reflux rate in the adjustment tank is set to 50%.

[0076] Table 3 Operation status of main unit equipment during the operation cycle

[0077]

[0078] After the mixed wastewater was treated through the above-mentioned cycle, the results were shown in Table 4, indicating that the reactor in the embodiment can efficiently remove nitrogen and phosphorus from wastewater.

[0079] Table 4 Water quality before and after sewage treatment in Example 3

[0080]

[0081] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A bioreactor based on denitrification and phosphorus removal, characterized in that: It includes an anaerobic tank, two sequencing batch tanks, two adjustment tanks, an aerobic tank and an anoxic tank; The anaerobic tank is used to receive the sewage to be treated and the activated sludge returned from the adjustment tank. The anaerobic phosphorus release process under the action of the activated sludge is carried out in the anaerobic tank, and the treated liquid in the anaerobic tank is input into different batch tanks. The sequencing batch tank is used to receive the treated liquid from the anaerobic tank and the return liquid from the aerobic tank and to carry out anoxic denitrification reaction under water inflow conditions, stirring conditions and pre-precipitation conditions therein; wherein, two sequencing batch tanks are connected in parallel to carry out multiple cycles of alternating reactions; in the first half of a reaction cycle, one sequencing batch tank receives the treated liquid from the anaerobic tank and the return liquid from the aerobic tank, and carries out anoxic denitrification reaction under water inflow conditions, and at the same time, discharges the supernatant after treatment in the previous cycle into the aerobic tank, and the remaining treated liquid enters the corresponding adjustment tank, while at the same time, the connecting parts between the other sequencing batch tank and the anaerobic tank and the aerobic tank are all in a closed state, and anoxic denitrification reaction under stirring conditions and pre-precipitation conditions is carried out in the sequencing batch tank in turn; in the second half of a reaction cycle, the operation and functions of the two sequencing batch tanks are interchanged; after a reaction cycle ends, the cycle enters the next reaction cycle; The two adjustment tanks are connected in series with different sequencing batch tanks respectively. The adjustment tank and the sequencing batch tank are always connected. The activated sludge in the adjustment tank is returned to the anaerobic tank, and the supernatant is discharged into the aerobic tank. The aerobic tank is used to receive the effluent from the sequencing batch tank and / or the adjustment tank, and aerobic carbonization and / or nitrification reactions are carried out in the aerobic tank; The anoxic tank is used to receive the treated liquid from the aerobic tank, and further denitrification and denitrification process is carried out in the anoxic tank.

2. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: The bioreactor based on denitrification and phosphorus removal is an integrated box structure, the treatment pools are connected through connecting valves, connecting pipes or water distribution systems, and the adjacent treatment pools share a wall plate.

3. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: The anaerobic tank treated liquid is input into different sequencing batch tanks through a thin-wall weir type water distribution device at the outlet of the anaerobic tank, and there is a liquid level difference between the anaerobic tank and the sequencing batch tank.

4. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: The anaerobic tank and sequencing batch tank are equipped with stirring devices; the adjustment tank is equipped with stirring devices and aeration devices.

5. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: The bottom surface of the sequencing batch pool is in the shape of a rectangle. The sequencing batch pool is connected to the bottom of the adjustment pool, and the adjustment pool is arranged on the water outlet side of the sequencing batch pool.

6. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: The aerobic pool is provided with biological fillers on which microbial films are cultured, and the microorganisms perform aerobic carbonization and / or nitrification reactions in the aerobic pool; the anoxic pool is provided with biological fillers on which microbial films are cultured, and the microorganisms perform anoxic denitrification reactions in the anoxic pool.

7. The bioreactor based on denitrification and phosphorus removal according to claim 1, characterized in that: Sludge discharge devices are installed in the adjustment tank, aerobic tank and anoxic tank.

8. A process for simultaneous nitrogen and phosphorus removal from sewage, characterized in that: The wastewater to be treated is input into the bioreactor based on denitrification and phosphorus removal as described in any one of claims 1 to 7 to carry out simultaneous denitrification and phosphorus removal treatment of the wastewater.

9. The process for simultaneous nitrogen and phosphorus removal from sewage according to claim 8, characterized in that: During the process of simultaneous denitrification and phosphorus removal in sewage, the dissolved oxygen in the anaerobic tank is controlled to be less than 0.2 mg / L, the redox potential ORP is controlled to be less than -200 mV, the dissolved oxygen in the sequencing batch tank is controlled to be less than 0.5 mg / L, the dissolved oxygen in the aerobic tank is controlled to be 2-4 mg / L, and the dissolved oxygen in the anoxic tank is controlled to be less than 0.5 mg / L.

10. The process for simultaneous nitrogen and phosphorus removal from sewage according to claim 8, characterized in that: The adjustment tank is stirred or aerated or a carbon source is added for reaction according to the components of the received liquid; when the total phosphorus in the influent of the adjustment tank is greater than 0.5 mg / L and the nitrate nitrogen content is less than 3 mg / L, the aeration device of the adjustment tank is turned on and the dissolved oxygen is controlled, and the dissolved oxygen provided by the aeration process is used as an electron acceptor to enhance the removal of total phosphorus; when the nitrate nitrogen content in the influent of the adjustment tank is greater than 5 mg / L, the stirring device of the adjustment tank is turned on and a carbon source is added to the adjustment tank to enhance the removal of total nitrogen; under other conditions, the aeration device and stirring device of the adjustment tank are in a closed state to further precipitate the activated sludge and increase the activated sludge content in the return liquid.

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