A sewage treatment device with multi-mode operation

Abstract

A multi-mode sewage treatment device belongs to the field of sewage treatment systems. Four groups of fixed tanks are arranged in parallel, and each group of fixed tanks is provided with a fixed guide wall, a movable guide device, an aeration device, etc. at both ends. The movable guide device can realize the volume distribution of different reaction tanks, achieving the best denitrification and phosphorus removal treatment effect. The entire tank body is covered with aeration devices, and the valves on the aeration devices control whether the aeration in each area is turned on to achieve aerobic / anoxic / anaerobic conditions. The multi-stage A / O operation mode with segmented water inlet: strengthens biological denitrification, maximizes the utilization of carbon sources in sewage, eliminates the need for internal recirculation, and saves energy. The system sludge concentration is higher than that of traditional biochemical tanks. According to the water quality conditions, multiple modes can be operated alternately, and there can be up to 7 alternating operation modes; the operation modes are diverse and flexible and convenient to switch, which can adapt to large changes in influent water quality and meet the requirements of effluent water quality.

Description

Technical Field

[0001] The present invention relates to a sewage treatment device, belonging to the field of sewage treatment systems, and in particular to a biological denitrification and dephosphorization reaction device capable of realizing multi-mode operation. Background Art

[0002] In recent years, wastewater treatment has entered a stage of advanced treatment that requires both efficient organic matter removal and efficient nitrogen and phosphorus removal. The most common A / O process is a biological treatment process developed by researchers for anoxic nitrogen removal or anaerobic phosphorus release. Its main feature is that the anoxic or anaerobic tank is in the front and the aerobic tank is in the back. During operation, the mixed liquid is returned to the front anoxic tank or the activated sludge is returned to the front anaerobic tank, and the carbon source of the sewage is used for denitrification and nitrogen removal or phosphorus removal. In order to meet the requirements of simultaneous nitrogen and phosphorus removal, people have developed the traditional A / A / O process. Its main feature is that the sewage flows into a biological reactor consisting of an anaerobic tank, an anoxic tank, and an aerobic tank in sequence. During this process, the sludge is returned to the anaerobic section to enrich the phosphate-accumulating bacteria using the organic matter in the sewage; the mixed liquid is returned to the anoxic section to complete the denitrification process.

[0003] The traditional A / A / O process can achieve the goal of simultaneous nitrogen and phosphorus removal within the same process system, but it also has some drawbacks. For example, due to the conflicts and competition between nitrifying bacteria and phosphate-accumulating bacteria in terms of organic load, sludge age, and carbon source demand, it is difficult to control the optimal reaction conditions of the anoxic and anaerobic tanks separately. For example, when the mixed liquor is returned to the anoxic tank, its dissolved oxygen concentration is relatively high, which will consume some carbon source, affecting the denitrification reaction and may cause poor anoxic conditions, thus affecting the denitrification effect. For example, when encountering seasonal changes in incoming water quality or changes in residents' lifestyles, the traditional A / A / O process, which is designed for a single water treatment requirement, has difficulty adapting to changes in water temperature and water quality, resulting in less than ideal treatment results and even failing to meet discharge requirements.

[0004] Therefore, if it is possible to switch between multiple operating modes in a certain process system according to the actual situation of the influent water quality / water quantity, and to be resistant to shock loads, it is possible to achieve efficient biological nitrogen and phosphorus removal when the influent water quality / water quantity changes greatly. Summary of the Invention

[0005] After a long period of exploration and research, the inventors of this application have addressed the problem that the secondary biochemical reaction pools in existing sewage treatment plants are unable to meet the standards for total nitrogen and / or total phosphorus treatment in water bodies when the influent water quality and / or influent water volume changes due to the single operating mode. By changing the single operating mode of the traditional biochemical pool, a multi-mode operating sewage treatment device has been developed that can adjust the operating mode according to changes in the influent water quality and / or influent water volume, and provide a guarantee for dephosphorization. That is, a multifunctional biochemical pool for biological denitrification and phosphorus removal that can achieve multi-mode operation, thereby solving the problem that the traditional sewage treatment process of biological denitrification and phosphorus removal cannot meet the emission standards at the same time. The device is flexible, stable and reliable in operation, and can implement multiple modes of operation in response to changes in water quality and water volume, thereby stably meeting the emission standards. The device also has the advantages of a small footprint, simple operation, unmanned operation, and low management and maintenance costs.

[0006] The multifunctional biochemical pool for biological denitrification and phosphorus removal capable of multi-mode operation is characterized in that: Figure 1As shown, four groups of fixed pool bodies are arranged in parallel, and a fixed guide wall is provided at each end of each group of fixed pool bodies, and a total of 8 guide walls are sequentially recorded as W1-W8; at the same time, a movable guide device with a water hole is provided in each group of fixed reaction pools, which is opposite to the fixed guide wall. The four groups of fixed reaction pools have a total of four movable guide devices, which are sequentially recorded as MW1-MW4. The bottom of the side of the four groups of fixed reaction pool bodies is connected by water holes H1-H3; each movable guide device divides the corresponding fixed reaction pool into small reaction pools, MW1 -MW4 divides the four fixed reaction pools into eight small reaction pools, which are marked as T1-T8. Aeration devices are evenly arranged in the eight small reaction pools T1-T8. Aeration fans A provide air source to the aeration devices in each pool through valves. There are eight valves in total, marked as AV1-AV8, that independently control the start and stop of the aeration devices in each small reaction pool T1-T8 (electric / pneumatic valves are optional). Each fixed pool body is a plug-flow reaction. A submersible flow pusher M is installed in each of the eight small reaction pools T1-T8, so that the air entering the corresponding small reaction pool is pumped into the water. The sewage in the pool should be able to enter the small reaction pool T8 from the small reaction pool T1 in sequence under the driving action of the submersible flow propeller M, and the effluent from the small reaction pool T8 enters the sedimentation pool; the device is provided with an inlet pipeline and an inlet valve that can meet the needs of multi-point water inlet. Each group of fixed pool bodies corresponds to an inlet pipeline and an inlet valve, with a total of four inlet valves V1-V4; the connection points of the inlet pipeline and the inlet valve are the small reaction pool T1, the small reaction pool T3, the small reaction pool T5, and the small reaction pool T7 respectively. The four inlet valves V1-V4 can be flexibly opened and closed according to the water inlet flow. The layout of the water inlet points is controlled according to different operating modes; a reflux valve RV1 is set up in the small reaction tank T1, and a reflux valve RV2 is set up in the small reaction tank T3, both of which are connected to the sedimentation tank via the nitrification liquid reflux pipe via the nitrification liquid reflux pump P1; the bottom of the sedimentation tank is connected to the small reaction tank T1 via the sludge reflux pipe via the sludge reflux pump P2, and the small reaction tank T8 is connected to the sedimentation tank; RV1-RV3 can be flexibly opened and closed, and according to different operating modes, the nitrification liquid can flow back to the small reaction tank T1 and the small reaction tank T3, and the secondary sedimentation sludge can flow back to the small reaction tank T1.

[0007] The four fixed pool bodies are all rectangular parallelepiped structures, and the four fixed pool bodies are arranged in parallel in a parallel manner in the length direction.

[0008] According to the direction of water flow in the four fixed pool bodies, four groups of fixed pool bodies are connected in series, and then eight small reaction pools T1-T8 are connected in series.

[0009] The volumes of the two small reaction pools in the fixed reaction pools are adjusted by adjusting the position of the movable flow guide device in each group of fixed reaction pools.

[0010] The multi-mode biological denitrification and dephosphorization reaction device provided by the present invention has the following advantages:

[0011] (1) The modules of the biological reactor are organically combined in one tank, which is intensive, occupies a small area, and has a small number of equipment. It can operate in multiple modes according to the water quality, and there are up to 7 alternating operation modes. The operation modes are diverse and the switching is flexible and convenient. It can adapt to large changes in the influent water quality and meet the effluent water quality requirements.

[0012] (2) The movable flow guide device can realize the volume distribution of different reaction pools to achieve the best denitrification and phosphorus removal treatment effect.

[0013] (3) The entire pool is covered with aeration devices, and the valves on the aeration devices are used to control whether the aeration in each area is turned on to achieve aerobic / anoxic / anaerobic conditions.

[0014] (4) Segmented water inlet multi-stage A / O operation mode: Enhanced biological denitrification, maximized utilization of carbon sources in wastewater, no need for internal recirculation, saving energy. The system sludge concentration is higher than that of traditional biochemical tanks. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 Schematic diagram of a sewage treatment plant operating in multiple modes;

[0017] W1-W8 are 8 diversion walls, MW1-MW4 are 4 movable diversion devices, H1-H3 are 3 water holes, T1-T8 are 8 small reaction tanks, AV1-AV8 are 8 valves; V1-V4 are 4 water inlet valves, RV1-RV3 are 3 return valves, P1 is the nitrification liquid return pump, P2 is the sludge return pump, A is the aeration fan, and B is the sedimentation tank.

[0018] Figure 2 Anaerobic-aerobic operation mode (A P / O) schematic diagram of the device;

[0019] Figure 3 Operation mode 2: anoxic-aerobic (A N / O) schematic diagram of the device;

[0020] Figure 4 Schematic diagram of the anaerobic-anoxic-aerobic (A / A / O) device in operating mode three;

[0021] Figure 5Schematic diagram of the anoxic-anaerobic-aerobic (inverted A / A / O) device for operation mode four;

[0022] Figure 6 Schematic diagram of the device for operation mode five: anaerobic-anoxic 1-aerobic 1-anoxic 2-aerobic 2 (A / A / O / A / O);

[0023] Figure 7 This is a schematic diagram of a six-stage water inlet multi-stage AO (A / O+A / O+A / O+A / O) device in operation mode;

[0024] Figure 8 Schematic diagram of a multi-stage AO (A / A / O) device with water inlet at seven points in the operating mode. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.

[0026] Example 1

[0027] Operation mode 1: Anaerobic-aerobic (A P / O). For example Figure 2 As shown, the inlet valve V1 is opened, allowing the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anaerobic small reactor T1 (an anaerobic state is achieved by closing the corresponding aeration valve AV1 of this small reactor, the same below). Driven by the submersible flow propeller (M) within the small reactor, the sewage then passes through the anaerobic small reactor T2 (an anaerobic state is achieved by closing the corresponding aeration valve AV2 of this small reactor, the same below) and the anaerobic small reactor T3 (an anaerobic state is achieved by closing the corresponding aeration valve AV3 of this small reactor, the same below). The small reactors T1, T2, and T3 are connected through bottom water holes. Simultaneously, the system's sludge return pump (P2) and return valve (RV3) are opened to return a certain amount of activated sludge from the secondary sedimentation tank to the anaerobic small reactor T1, replenishing the number of active phosphorus-containing microorganisms in the anaerobic reactor. In the anaerobic tanks, phosphate-accumulating bacteria release phosphorus and, through their own activities, absorb easily degradable organic matter, such as low-level fatty acids, from the raw sewage, reducing the BOD5 content to a certain extent. The sewage then continues to flow through the submersible flow propeller (M) into aerobic small reaction tanks T4-T8 (achieving an aerobic state by opening the corresponding aeration valves AV4-AV8, similarly below). These small reaction tanks are connected by bottom water holes. In the aerobic tanks, organic matter in the sewage continues to be degraded by aerobic microorganisms, significantly reducing the BOD5 content. Simultaneously, the phosphate-accumulating bacteria oxidize and decompose the organic matter stored in their bodies, generating energy. They also absorb excess phosphorus from the sewage and store it in the form of polyphosphates. This excess sludge is ultimately discharged from the system as residual sludge, achieving the goal of removing phosphorus from the sewage.

[0028] The AP The characteristics of the / O process are high rate and short hydraulic retention time. In a typical design, the retention time in the anaerobic zone is 0.5-1.0 hours, and in the aerobic zone is 1-3 hours. The sludge age of the system is also short, so the system often cannot achieve nitrification, and the return sludge will not carry NO3 - 、NO2 - To the anaerobic zone. This process is a biological phosphorus removal process that only removes phosphorus, not nitrogen. Under anaerobic-aerobic operating conditions, filamentous bacteria do not reproduce significantly, and the sludge volume index (SVI) is generally less than 100, making sludge bulking less likely and sludge settling more easily. The residual sludge discharged from the system has a high phosphorus content and is highly effective as a fertilizer.

[0029] Example 2

[0030] Operation mode 2: Anoxic-aerobic (A N / O). For example Figure 3 As shown, opening the water inlet valve V1 allows the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anoxic small reaction tank T1 (an anoxic state is achieved by closing the corresponding aeration valve AV1 of this small reaction tank, the same below). Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then passes through the anoxic small reaction tank T2 (an anoxic state is achieved by closing the corresponding aeration valve AV2 of this small reaction tank, the same below) and the anoxic small reaction tank T3 (an anoxic state is achieved by closing the corresponding aeration valve AV3 of this small reaction tank, the same below). The small reaction tanks T1, T2, and T3 are connected by water holes at the bottom. At the same time, the system's nitrification liquid return pump (P1), sludge return pump (P2), and return valves (RV2, RV3) are turned on to return a certain amount of aerobic tank mixed liquid containing higher concentrations of NO3-N and NO2-N to the anoxic small reaction tank T1 to prepare for the denitrification reaction in the anoxic tank. A certain amount of activated sludge from the secondary sedimentation tank is also returned to the anoxic small reaction tank T1 to replenish the amount of active microorganisms in the anaerobic reaction tank. In the anoxic tank, denitrifying bacteria use organic matter in the sewage as a carbon source, reducing the large amount of NO3-N and NO2-N brought into the return mixed liquid to N2, which is released into the air, thereby achieving the purpose of removing nitrogen from the sewage. At the same time, the BOD5 content in the sewage will be reduced to a certain extent. The wastewater then enters aerobic small reaction tanks T4-T8 (aerobic conditions are achieved by opening the corresponding aeration valves AV4-AV8, similarly below) under the action of the submersible flow propeller (M). These small reaction tanks are connected by bottom water holes. In the aerobic tanks, the organic matter in the wastewater is biodegraded by microorganisms, further reducing its BOD5 content. Organic nitrogen is ammonified and then nitrified, significantly reducing the NH3-N concentration. However, as the nitrification process progresses, the NO3-N concentration increases.

[0031] The A NThe / O process is characterized by a simple system flow, no need for an external carbon source and post-aeration tank, and can use the organic matter in the raw water as a carbon source for denitrification reaction, thereby achieving the purpose of simultaneously removing organic matter and denitrification in the sewage; the sewage finally passes through an aerated aerobic tank to further remove denitrification products and improve the effluent water quality.

[0032] Example 3

[0033] Operation mode three: anaerobic-anoxic-aerobic (A / A / O). Figure 4As shown, opening the inlet valve V1 allows the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anaerobic (anaerobic) small reaction tank T1 (achieved by closing the corresponding aeration valve AV1 for this small reaction tank, similarly hereinafter) small reaction tank T2. Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anaerobic (anaerobic) small reaction tank T2 (achieved by closing the corresponding aeration valve AV2 for this small reaction tank, similarly hereinafter) small reaction tank T3. Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anoxic (anoxic) small reaction tank T3 (achieved by closing the corresponding aeration valve AV3 for this small reaction tank, similarly hereinafter) small reaction tank T4 (achieved by closing the corresponding aeration valve AV4 for this small reaction tank, similarly hereinafter) small reaction tank T4. Small reaction tanks T1, T2, T3, and T4 are connected by water holes at the bottom. At the same time, the system's nitrification liquid return pump (P1), sludge return pump (P2), and return valves (RV1 and RV3) are turned on to return a certain amount of the aerobic tank mixed liquid, containing high concentrations of NO3-N and NO2-N, to the anoxic small reactor T3 to prepare for the denitrification reaction in the anoxic tank. A certain amount of activated sludge from the secondary sedimentation tank is also returned to the anaerobic small reactor T1 to replenish the number of phosphorus-containing active microorganisms in the anaerobic reactor. In the anaerobic tank, polyphosphate bacteria release phosphorus and, during their own life activities, absorb easily degradable organic matter such as low-level fatty acids from the raw sewage, reducing the BOD5 content in the sewage to a certain extent. In the anoxic tank, denitrifying bacteria use the organic matter in the sewage as a carbon source, reducing the large amount of NO3-N and NO2-N introduced in the return mixed liquid to N2, which is released into the air, thereby removing nitrogen from the sewage. At the same time, microbial activity consumes organic matter in the sewage, and the BOD5 content in the sewage continues to decrease. The sewage then enters aerobic small reaction tanks T5-T8 (aerobic conditions are achieved by opening the corresponding aeration valves AV5-AV8 for each small reaction tank, similarly below) under the action of the submersible flow propeller (M). These small reaction tanks are connected by bottom water holes. In the aerobic tanks, organic matter in the sewage is biodegraded by microorganisms, further reducing the BOD5 content. Organic nitrogen is ammonified and then nitrified, significantly reducing the NH3-N concentration. However, as the nitrification process progresses, the NO3-N concentration increases. At the same time, phosphate-accumulating bacteria absorb excess phosphorus from the sewage and store it in their bodies as polyphosphates. This is ultimately discharged from the system as excess sludge, effectively removing phosphorus from the sewage.

[0034] The A / A / O process is characterized by its ability to organically combine three different environmental conditions, namely anaerobic, anoxic and aerobic, and different types of microbial flora in the same system, simultaneously removing organic matter, nitrogen and phosphorus. Among processes that simultaneously remove nitrogen, phosphorus and organic matter, this process has the simplest flow and a total hydraulic retention time that is shorter than other similar processes. Under the alternating anaerobic-anoxic-aerobic operation, filamentous bacteria do not reproduce in large numbers, the SVI is generally less than 100, and sludge bulking does not occur. The sludge has a high phosphorus content, generally above 2.5%, and has good fertilizer efficiency.

[0035] Example 4

[0036] Operation mode 4: Anoxic-Anaerobic-Aerobic (inverted A / A / O). Figure 5 As shown, the inlet valve V1 is opened, allowing the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anoxic (anoxic state is achieved by closing the corresponding aeration valve AV1 of this small tank, the same below) small reaction tank T1. Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anoxic (anoxic state is achieved by closing the corresponding aeration valve AV2 of this small tank, the same below). The sewage then enters the anaerobic (anaerobic state is achieved by closing the corresponding aeration valve AV3 of this small tank, the same below) small reaction tank T3. Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anaerobic (anaerobic state is achieved by closing the corresponding aeration valve AV4 of this small tank, the same below) water reaction tank T4. The small reaction tanks T1, T2, T3, and T4 are connected through bottom water holes. Simultaneously, the system sludge return pump (P2) and return valve (RV3) are opened to return some activated sludge from the secondary sedimentation tank to the anoxic small reaction tank T1. In the anoxic tank, denitrifying bacteria use organic matter in the sewage as a carbon source, reducing NO3-N and NO2-N introduced in the return sludge to N2, which is released into the air, thereby removing nitrogen from the sewage. At the same time, microbial activity consumes organic matter in the sewage, further reducing the BOD5 content in the sewage. In the anaerobic tank, polyphosphate bacteria release phosphorus and, during their own life activities, absorb easily degradable organic matter such as low-level fatty acids in the raw sewage, reducing the BOD5 content in the sewage to a certain extent. Then, under the action of the submersible flow propeller (M), the sewage enters the aerobic small reaction tanks T5-T8 in sequence (reaching an aerobic state by opening the aeration valves AV5-AV8 corresponding to these small reaction tanks, the same below). The small reaction tanks T5-T8 are connected by water holes at the bottom. In the aerobic tank, the organic matter in the sewage is biochemically degraded by microorganisms and continues to decrease, which greatly reduces the BOD5 content in the sewage; the organic nitrogen is ammonified and then nitrified, which significantly reduces the NH3-N concentration, but as the nitrification process progresses, the NO3-N concentration increases; at the same time, polyphosphate bacteria absorb excessive phosphorus in the sewage and store it in the body in the form of polyphosphate, which is eventually discharged from the system in the form of residual sludge to achieve the purpose of removing phosphorus from the sewage.

[0037] The inverted A / A / O process is characterized by the anoxic section being located at the front end of the process, and the denitrification reaction having priority in obtaining a more sufficient carbon source, which can further enhance the system's denitrification capacity; the sewage undergoes denitrification in the anoxic zone at the front end, consuming all the nitrates, and reducing the dissolved oxygen content in the sewage during the activity of the denitrifying bacteria, which is conducive to the subsequent formation of a stronger phosphorus absorption capacity by the polyphosphate bacteria entering the anaerobic zone; all returned sludge will participate in the complete phosphorus release-absorption process, and there is a "group effect" advantage in phosphorus removal; after anaerobically releasing phosphorus, the polyphosphate bacteria directly enter the aerobic environment with higher biochemical efficiency, and the phosphorus absorption power formed under anaerobic conditions can be more fully utilized.

[0038] Example 5

[0039] Operation mode 5: Anaerobic-Anoxic 1-Aerobic 1-Anoxic 2-Aerobic 2 (A / A / O / A / O). Figure 6As shown, opening the water inlet valve V1 allows the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anaerobic small reaction tank T1 (reaching an anaerobic state by closing the corresponding aeration valve AV1 for this small reaction tank, the same below). Driven by the submerged flow propeller (M) within the small reaction tank, the sewage then enters the anaerobic small reaction tank T2 (reaching an anaerobic state by closing the corresponding aeration valve AV2 for this small reaction tank, the same below). The sewage then enters the anoxic small reaction tank T3 (reaching an anoxic state by closing the corresponding aeration valve AV3 for this small reaction tank, the same below). Driven by the submerged flow propeller (M) within the small reaction tank, the sewage then enters the aerobic small reaction tank T4 (reaching an aerobic state by opening the corresponding aeration valve AV4 for this small reaction tank, the same below). Small reaction tanks T1, T2, T3, and T4 are connected via bottom water holes. At the same time, the system's nitrification liquid return pump (P1), sludge return pump (P2) and return valves (RV1, RV3) are turned on to return a certain amount of aerobic tank mixed liquid containing higher concentrations of NO3-N and NO2-N to the anoxic 1 small reaction tank T3 to prepare for the denitrification reaction in the anoxic tank, and a certain amount of activated sludge from the secondary sedimentation tank is returned to the anaerobic small reaction tank T1 to supplement the amount of phosphorus-containing active microorganisms in the anaerobic reaction tank. In the anaerobic tank, phosphate-accumulating bacteria release phosphorus and, during their own activities, absorb easily degradable organic matter, such as low-level fatty acids, from the raw sewage, reducing the BOD5 content to a certain extent. In the anoxic tank 1, the bacteria utilize organic matter in the sewage as a carbon source, using the large amounts of NO3-N and NO2-N introduced by the reflux mixture as electron acceptors for denitrification. Using the energy storage substances within the bacteria as electron donors for denitrification, they reduce nitrate nitrogen (NO3-N and NO2-N) to N2, which is released into the air, achieving the simultaneous removal of nitrogen and phosphorus from the sewage. Simultaneously, microbial activity consumes organic matter in the sewage, further reducing the BOD5 content. The sewage then enters the aerobic tank 1 (aerobic conditions are achieved by opening the corresponding aeration valves AV4-AV6, similarly below) and the small reactors T4-T6, connected by bottom water holes. In the aerobic tank, the organic matter in the sewage is biochemically degraded by microorganisms and continues to decrease, which greatly reduces the BOD5 content in the sewage; the organic nitrogen is ammonified and then nitrified, which significantly reduces the NH3-N concentration, but as the nitrification process progresses, the NO3-N concentration increases; at the same time, polyphosphate bacteria absorb excessive phosphorus in the sewage and store it in the body in the form of polyphosphate, which is eventually discharged from the system in the form of residual sludge to achieve the purpose of removing phosphorus from the sewage.The sewage then continues to enter the anoxic 2 (anoxic state is achieved by closing the aeration valve AV7 corresponding to this small reaction tank, the same below) reaction tank T7, and flows into the aerobic 2 (aerobic state is achieved by opening the aeration valve AV8 corresponding to this small reaction tank, the same below) reaction tank T8 through the bottom water hole. The sewage further undergoes denitrification reaction in the anoxic 2 reaction tank T7 using an external carbon source to enhance the denitrification effect of the sewage. Then, the removal of organic matter in the sewage, nitrification of ammonia nitrogen, and absorption of phosphorus are further completed in the aerobic 2 reaction tank T8.

[0040] The A / A / O / A / O process is distinguished by its denitrifying phosphorus removal process, which utilizes a dominant species of denitrifying phosphorus-accumulating bacteria, nitrate NO₃⁻ as an electron acceptor, and an internal carbon source as an electron donor. This "one carbon, two uses" approach allows for simultaneous denitrification and phosphorus uptake, enabling phosphorus removal and denitrification to be accomplished by the same microorganisms. This represents a significant breakthrough in the biological denitrification and phosphorus removal mechanisms. Furthermore, the process efficiently utilizes the carbon source in the influent, further enhancing the denitrification capacity of the A₂O process. This not only resolves the conflicting relationship between nitrogen removal and phosphorus removal in traditional anaerobic-anoxic-aerobic processes but also reduces operational energy consumption. In this process, NO₃⁻ is no longer simply considered an inhibitory factor in phosphorus removal; instead, it serves as the final electron acceptor for denitrification and phosphorus uptake. Therefore, the denitrifying phosphorus removal and denitrification process can be considered a sustainable process.

[0041] Example 6

[0042] Operation mode 6: Segmented water inflow: anoxic 1-aerobic 1-anoxic 2-aerobic 2-anoxic 3-aerobic 3-anoxic 4-aerobic 4 (A / O+A / O+A / O+A / O). This process uses multiple short-term anoxic-aerobic repeated operations to replace the single-stage anoxic-aerobic process, and divides the sewage into a certain proportion and enters the anoxic tank separately. Figure 7As shown, the movable guide device (MW1-MW4) is adjusted to make the capacity of the small reaction tanks T1-T2, T3-T4, T5-T6, and T7-T8 meet the requirements of the anoxic-aerobic process. The entire device becomes a sewage treatment system with multiple anoxic (by closing the aeration valves AV1, AV3, AV5, and AV7 corresponding to the small reaction tanks to achieve anoxic state, the same below) and aerobic (by opening the aeration valves AV2, AV4, AV6, and AV8 corresponding to the small reaction tanks to achieve aerobic state, the same below) processes in series. The small reaction tanks T1-T8 are connected by water holes at the bottom. Connected. At the same time, open the system sludge return pump (P2) and the return valve (RV3) to return part of the activated sludge from the secondary sedimentation tank to the anoxic small reaction tank T1 to replenish the amount of active microorganisms in the anoxic reaction tank. Open the water inlet valve V1 to allow the sewage that has undergone primary treatment in the sewage treatment plant to enter the anoxic small reaction tank T1 in a certain proportion, and then enter the aerobic reaction tank T2 under the driving action of the submersible flow pusher (M) in the small reaction tank. So far, the raw sewage has undergone a complete anoxic-aerobic process. Afterwards, under the action of the submersible flow pusher (M) in the small reaction tank, the sewage enters the small reaction tanks T3-T4, T 5-T6, T7-T8, repeat the anoxic-aerobic cycle. At the same time, open the water inlet valves V2, V3, and V4, so that the raw sewage enters the anoxic small reaction tanks T3, T5, and T7 at multiple points according to a certain proportion, and then mixes with the sewage flowing into the front pool and enters the next aerobic small reaction tank. In the anoxic tank, denitrifying bacteria use the organic matter in the sewage as a carbon source to carry out denitrification reaction, reducing NO3-N and NO2-N in the sewage to N2 and releasing it into the air, thereby achieving the purpose of removing nitrogen from the sewage. At the same time, microbial activity requires the consumption of organic matter in the sewage, and the BOD5 content in the sewage continues to decrease. Low. Driven by the submersible flow propellers (M) within the small reaction tanks, the wastewater continues to flow from the anoxic tank into the aerobic small reaction tanks T2, T4, T6, and T8. Within the aerobic tanks, the organic matter in the wastewater continues to decrease due to microbial biodegradation, significantly reducing the BOD5 content. Organic nitrogen is ammonified and then nitrified, significantly reducing the NH3-N concentration. However, as the nitrification process progresses, the NO3-N concentration increases. Simultaneously, phosphate-accumulating bacteria absorb excessive amounts of phosphorus from the wastewater and store it in their bodies as polyphosphates. This is ultimately discharged from the system as excess sludge, effectively removing phosphorus from the wastewater.

[0043] The characteristics of the segmented water inlet multi-stage A / O process are that the activated sludge can better exert its own vitality under the alternating aerobic-anoxic state, accelerate the degradation rate of pollutants in the aerobic state, and improve the efficiency of sewage treatment; during operation, the sewage undergoes the alternating anoxic-aerobic state, which strengthens the nitrification-denitrification process. The multi-stage A / O process has a shorter reaction time and higher NH3-N removal efficiency than the single nitrification-denitrification process; the segmented water inlet form can make full use of the carbon source in the sewage, saving the investment in additional carbon source in the denitrification process; since the sewage enters the reaction tank in sections according to a certain proportion, the dilution of the activated sludge returned from the secondary sedimentation tank is delayed, forming a sludge concentration gradient in space, and the activated sludge concentration in the first few sections is significantly higher than the design value of conventional activated sludge. This means that when the total amount of sludge in the biological pool and the solid load of the secondary sedimentation tank remain unchanged, high sludge concentration and low substrate concentration are formed in the local space, which reduces the load of activated sludge and promotes the degradation process of pollutants; no nitrification liquid return system is set up, which avoids the adverse effects of a large amount of dissolved oxygen brought in from the return liquid of the aerobic pool on the living environment of denitrifying bacteria, and ensures the progress of denitrification reaction in the anoxic pool.

[0044] Example 7

[0045] Operation mode seven: anaerobic-anoxic-aerobic with water inlet at different points (water inlet at different points A / A / O). Figure 8As shown, the inlet valve V1 is opened, allowing a certain proportion of the sewage, which has undergone primary treatment at the sewage treatment plant, to enter the anaerobic small reaction tank T1 (achieving an anaerobic state by closing the corresponding aeration valve AV1 for this small reaction tank, the same below). Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anaerobic small reaction tank T2 (achieving an anaerobic state by closing the corresponding aeration valve AV2 for this small reaction tank, the same below). The sewage then enters the anoxic small reaction tank T3 (achieving an anoxic state by closing the corresponding aeration valve AV3 for this small reaction tank, the same below). Driven by the submersible flow propeller (M) within the small reaction tank, the sewage then enters the anoxic small reaction tank T4 (achieving anoxic state by closing the corresponding aeration valve AV4 for this small reaction tank, the same below). Simultaneously, the inlet valve V2 is opened, allowing a certain proportion of the raw sewage to flow into the anoxic small reaction tank T3. The small reaction tanks T1, T2, T3, and T4 are connected by water holes at the bottom. At the same time, the system's nitrification liquid return pump (P1), sludge return pump (P2), and return valves (RV1 and RV3) are turned on to return a certain amount of the aerobic tank mixed liquid, containing high concentrations of NO3-N and NO2-N, to the anoxic small reactor T3 to prepare for the denitrification reaction in the anoxic tank. A certain amount of activated sludge from the secondary sedimentation tank is also returned to the anaerobic small reactor T1 to replenish the number of phosphorus-containing active microorganisms in the anaerobic reactor. In the anaerobic tank, polyphosphate bacteria release phosphorus and, during their own life activities, absorb easily degradable organic matter such as low-level fatty acids from the raw sewage, reducing the BOD5 content in the sewage to a certain extent. In the anoxic tank, denitrifying bacteria use the organic matter in the sewage as a carbon source, reducing the large amount of NO3-N and NO2-N introduced in the return mixed liquid to N2, which is released into the air, thereby removing nitrogen from the sewage. At the same time, microbial activity consumes organic matter in the sewage, and the BOD5 content in the sewage continues to decrease. The sewage then enters aerobic small reaction tanks T5-T8 (aerobic conditions are achieved by opening the corresponding aeration valves AV5-AV8, the same below) under the action of the submersible flow propeller (M). These small reaction tanks are connected by bottom water holes. In the aerobic tanks, organic matter in the sewage is biodegraded by microorganisms, further reducing the BOD5 content. Organic nitrogen is ammonified and then nitrified, significantly reducing the NH3-N concentration. However, as the nitrification process progresses, the NO3-N concentration increases. At the same time, phosphate-accumulating bacteria absorb excess phosphorus from the sewage and store it in their bodies as polyphosphates. This is eventually discharged from the system as excess sludge, achieving the goal of removing phosphorus from the sewage.

[0046] The characteristic of this point-inlet A / A / O process is that in addition to the advantages of traditional A / A / O, the water inlet point set in the anoxic tank can make greater use of the carbon source in the sewage, promote the denitrification reaction, and save the investment in adding an external carbon source to the anoxic tank. It is a process that takes into account both denitrification and phosphorus removal.

Claims

1. A multi-mode sewage treatment device, characterized in that: Four groups of fixed pool bodies are set in parallel, and a fixed guide wall is set at both ends of each group of fixed pool bodies, and a total of 8 guide walls are marked as W1-W8 in sequence; at the same time, a movable guide device with a water hole opposite to the fixed guide wall is set in each group of fixed reaction pools, and a total of four movable guide devices of the four groups of fixed reaction pools are marked as MW1-MW4 in sequence. The bottom of the side of the four groups of fixed reaction pool bodies is connected by water holes H1-H3; each movable guide device divides the corresponding fixed reaction pool into small reaction pools, MW 1-MW4 divides the four fixed reaction pools into 8 small reaction pools, which are marked as T1-T8. Aeration devices are evenly arranged in the 8 small reaction pools T1-T8. The aeration fan A provides air source to the aeration devices in each pool through the valve. The valves for individually controlling the start and stop of the aeration devices in each small reaction pool T1-T8 are 8 in total, marked as AV1-AV8. Each fixed pool body is a plug-flow reaction. Each of the 8 small reaction pools T1-T8 is equipped with a submersible flow pusher M, so that the sewage entering the corresponding small pool should be able to Under the driving action of the submersible flow propeller M, the water enters the small reaction pool T8 from the small reaction pool T1 in turn, and the water from the small reaction pool T8 enters the sedimentation pool; the device is provided with a water inlet pipeline and a water inlet valve that can meet the needs of multi-point water inlet. Each group of fixed pool bodies corresponds to an inlet pipeline and a water inlet valve, with a total of four water inlet valves V1-V4; the connection points of the water inlet pipeline and the water inlet valve are small reaction pool T1, small reaction pool T3, small reaction pool T5, and small reaction pool T7 respectively. The four water inlet valves V1-V4 can be flexibly opened and closed according to different The operation mode controls the layout of the water inlet points; a reflux valve RV1 is installed in the small reaction tank T1, and a reflux valve RV2 is installed in the small reaction tank T3, both of which are connected to the sedimentation tank via a nitrification liquid reflux pipe via a nitrification liquid reflux pump P1. The bottom of the sedimentation tank is connected to the small reaction tank T1 via a sludge reflux pipe via a sludge reflux pump P2, and the small reaction tank T8 is connected to the sedimentation tank. RV1-RV3 can be flexibly opened and closed, depending on the operation mode, so that the nitrification liquid can flow back to the small reaction tanks T1 and T3, and the secondary sedimentation sludge can flow back to the small reaction tank T1. Perform multiple modes: anaerobic-aerobic (A P / O), hypoxia-aerobic (A N / O), anaerobic-anoxic-aerobic (A / A / O), anoxic-anaerobic-aerobic (inverted A / A / O), anaerobic-anoxic 1-aerobic 1-anoxic 2-aerobic 2 (A / A / O / A / O), staged water inflow anoxic 1-aerobic 1-anoxic 2-aerobic 2-anoxic 3-aerobic 3-anoxic 4-aerobic 4 (A / O+A / O+A / O+A / O), anaerobic-anoxic-aerobic with divided water inflow (divided water inflow A / A / O); The operation mode of anaerobic-anoxic 1-aerobic 1-anoxic 2-aerobic 2 (A / A / O / A / O) is as follows: open the water inlet valve V1 to allow the sewage after the primary treatment of the sewage treatment plant to enter the anaerobic small reaction tank T1, and enter the anaerobic small reaction tank T2 under the driving action of the submersible flow pusher M in the small reaction tank; then the sewage enters the anoxic 1 small reaction tank T3, and enters the aerobic small reaction tank T4 under the driving action of the submersible flow pusher M in the small reaction tank; the small reaction tanks T1, T2, T3, and T4 are connected through the water holes at the bottom; at the same time, open the system's nitrification liquid return pump P1, sludge return pump P2 and return valves RV1 and RV3 to return a certain amount of aerobic pool mixed liquid containing higher concentrations of NO3-N and NO2-N It flows to the anoxic 1 small reaction tank T3 to prepare for the denitrification reaction in the anoxic tank, and returns a certain amount of activated sludge from the secondary sedimentation tank to the anaerobic small reaction tank T1 to replenish the amount of phosphorus-containing active microorganisms in the anaerobic reaction tank; then, under the action of the submersible flow propeller M, the sewage enters the aerobic 1 small reaction tanks T4-T6 in sequence, and the small reaction tanks T4-T6 are connected by water holes at the bottom; then the sewage continues to enter the anoxic 2 reaction tank T7 and flows into the aerobic 2 reaction tank T8 through the bottom water holes. The sewage further undergoes denitrification reaction in the anoxic 2 reaction tank T7 using an external carbon source to enhance the denitrification effect of the sewage. Then, in the aerobic 2 reaction tank T8, the removal of organic matter in the sewage, nitrification of ammonia nitrogen, and absorption of phosphorus are further completed.

2. A multi-mode sewage treatment device according to claim 1, characterized in that: AV1-AV8 are optional electric or pneumatic valves.

3. A multi-mode sewage treatment device according to claim 1, characterized in that: The four fixed pool bodies are all rectangular parallelepiped structures, and the four fixed pool bodies are arranged in parallel in a parallel manner in the length direction.

4. A multi-mode sewage treatment device according to claim 1, characterized in that: According to the direction of water flow in the four fixed pool bodies, four groups of fixed pool bodies are connected in series, and then eight small reaction pools T1-T8 are connected in series.

5. A multi-mode sewage treatment device according to claim 1, characterized in that: The volumes of the two small reaction pools in the fixed reaction pools are adjusted by adjusting the position of the movable flow guide device in each group of fixed reaction pools.

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