A2 / O-Based Membrane Bioreactor Wastewater Treatment System

Abstract

The present invention relates to an A2 / O-based membrane bioreaction wastewater treatment system comprising an anaerobic tank (10), an anoxic tank (20), an aerobic reactor (30), a membrane separation unit (40), and a treated water tank (50), and is characterized by including a stirrer (100) with adjustable blade inclination angle inside the aerobic reactor (30). The stirrer (100) comprises a rotating shaft (110), a plurality of blades (120), an angle adjustment unit (130), and foldable first blades (124) and second blades (126), and is configured so that the blade inclination angle and folding state vary according to changes in the viscosity and flow state of the wastewater. Accordingly, the present invention can improve mixing uniformity and reduce sludge concentration deviation and the occurrence of local stagnation areas.

Description

Technology Field

[0001] The present invention relates to the field of wastewater treatment technology, and more specifically, to an A2 / O-based membrane bioreactor wastewater treatment system equipped with a stirrer having a variable blade inclination angle inside an aerobic MBR (Membrane Bio-Reactor) reactor, which improves mixing uniformity and mixing stability inside the treatment tank and maintains a stable mixing state in response to changes in wastewater viscosity.

[0002] More specifically, the present invention relates to an A2 / O-based membrane bioreaction wastewater treatment system capable of reducing local stagnation areas inside a treatment tank and improving mixing efficiency by including a stirrer configured such that the inclination angle of the blade is adjustable and the blade can be folded and returned according to fluid resistance. Background Technology

[0003] Recently, as effluent quality standards have been strengthened in the field of wastewater treatment, the application of advanced treatment processes capable of simultaneously removing not only organic matter but also nutrients such as nitrogen and phosphorus is expanding. In particular, the A2 / O process, which includes an anaerobic, anoxic, and oxic tank, is widely used as an effective process for biological nitrogen and phosphorus removal. Recently, the A2 / O-MBR process, which combines a Membrane Bioreactor (MBR) to improve treated water quality and reduce installation area, is being applied to various wastewater treatment facilities.

[0004] The above A2 / O-MBR process has the advantage of maintaining high concentrations of microorganisms and securing excellent solid-liquid separation performance by combining biological treatment using activated sludge with a membrane separation process. In addition, it allows for facility intensification by replacing or reducing the sedimentation tank, and has the advantage of significantly lowering the turbidity and suspended solids concentration of the effluent.

[0005] However, in the conventional A2 / O-MBR process, there was a problem where the flow inside the aerobic reactor was localized or a dead zone was formed. In particular, when the activated sludge concentration increased, the viscosity of the mixture increased, which could lower the mixing efficiency and biological treatment efficiency, and there was a problem where the nitrification efficiency and organic matter removal efficiency became unstable due to variations in sludge concentration inside the reactor.

[0006] In addition, most conventional agitators consist of a simple rotating structure with a fixed blade angle, which made it difficult to actively respond to changes in wastewater viscosity or operating conditions. Consequently, excessive turbulence occurred in certain areas, while conversely, insufficient mixing occurred in some areas, leading to problems such as variations in sludge concentration and the formation of stagnant areas within the treatment tank.

[0007] In particular, when the concentration of activated sludge increases, the viscosity of the mixture rises, which can reduce stirring efficiency; conventional structures had limitations in that it was difficult to properly control the flow state in response to such viscosity changes.

[0008] Therefore, there is a need to develop an A2 / O-based membrane bioreaction wastewater treatment system that includes a stirrer of a new structure capable of variably adjusting the blade inclination angle and mixing state in response to changes in wastewater viscosity and flow state.

[0010] [Prior Art Literature]

[0011] [Patent Literature]

[0012] Korean Patent Registration No. 10-2882982-0000 (2025.11.04) The problem to be solved

[0013] The present invention is proposed to solve the above-mentioned problems and aims to provide an A2 / O-based membrane bioreaction wastewater treatment system that can improve the uniformity of mixing inside the treatment tank by reducing local stagnation zones and sludge concentration variations formed inside the aerobic reactor.

[0014] In addition, another objective of the present invention is to provide a wastewater treatment system capable of maintaining a stable mixing state even under various operating conditions by variably adjusting the blade angle and flow formation of the agitator according to changes in the viscosity of the wastewater, MLSS (activated sludge suspended solids, hereinafter MLSS) concentration and flow rate.

[0015] In addition, another objective of the present invention is to provide an A2 / O-based membrane bioreaction wastewater treatment system capable of improving biological treatment efficiency by enhancing the contact efficiency between activated sludge and air, and improving nitrification and organic matter decomposition efficiency.

[0016] In addition, another objective of the present invention is to provide an A2 / O-based membrane bioreaction wastewater treatment system capable of reducing energy consumption while improving treatment efficiency by analyzing operating conditions such as COD (Chemical Oxygen Demand), SS (Suspended Solids), viscosity, and flow rate of wastewater in real time, and thereby optimally controlling the rotational speed and blade inclination angle of the agitator based on artificial intelligence accordingly.

[0017] The problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0018] The technical problem of the present invention as described above is achieved by the following means.

[0019] (1) In an A2 / O-based membrane bioreaction wastewater treatment system for removing organic matter and nitrogen and phosphorus components contained in influent wastewater,

[0020] An anaerobic tank (10) that performs pretreatment of organic matter and phosphorus components contained in the influent wastewater;

[0021] An anoxic tank (20) that performs a denitrification reaction on the mixture that has passed through the above anaerobic tank (10);

[0022] An aerobic reaction tank (30) equipped with an internal stirrer (100) and performing organic oxidation and nitrification reactions on the mixture that has passed through the anaerobic tank (20);

[0023] A membrane separation unit (40) for separating treated water and activated sludge from the mixture of the above-mentioned aerobic reaction tank (30);

[0024] A treated water tank (50) for storing treated water that has passed through the above membrane separation unit (40); and

[0025] It includes an artificial intelligence control unit (300) that controls the operating state of the agitator (100) according to changes in the characteristics of the wastewater, and

[0026] The above stirrer (100) is,

[0027] A rotating shaft (110) that transmits rotational force;

[0028] A plurality of blades (120) coupled to the above-mentioned rotating shaft (110) to form a fluid flow; and

[0029] It includes a rotation drive unit (140) that rotates the above rotation shaft (110), and

[0030] The blade (120) has a blade shaft (122) as its central axis, and the blade shaft (122) is installed to be rotatable about the rotation axis (110).

[0031] The above-mentioned stirrer (100) includes an angle adjustment unit (130) that rotates the blade shaft (122) to adjust the inclination angle of the blade (120), and

[0032] The above angle adjustment unit (130) is,

[0033] An operating space (131) formed inside the above-mentioned rotating shaft (110);

[0034] An operating shaft (132) installed to be movable along the above operating space (131);

[0035] A control drive unit (133) that moves the above operating shaft (132) in the longitudinal direction of the operating space;

[0036] A driven gear (134) installed at the end of the blade shaft (122) of the blade (120);

[0037] A drive block (135) coupled to the above-mentioned operating shaft (132) and moved together with it;

[0038] and a rack gear (136) formed in the drive block (135) to mesh with the driven gear (134);

[0039] Includes,

[0040] The above blade (120) is,

[0041] A first blade (124) and a second blade (126) are arranged on both sides based on the blade shaft (122) and formed to be foldable;

[0042] and a blade original position part (128) that returns the folded first blade (124) and second blade (126) to an unfolded state;

[0043] Includes,

[0044] An A2 / O-based membrane bioreaction wastewater treatment system characterized in that the first blade (124) and the second blade (126) are each composed of a first blade piece (125) and a second blade piece (127) that are segmented into multiple parts and formed to be individually foldable.

[0045] (2) In the above (1), installed at the front of the anaerobic tank (10),

[0046] A properties sensor (5a) for measuring the viscosity, turbidity, and SS concentration of the influent wastewater; and,

[0047] An A2 / O-based membrane bioreaction wastewater treatment system characterized by further including an inflow homogenization tank (5) comprising a selective circulation mixing unit (5b) that circulates a portion of the mixture inside the inflow homogenization tank (5) to mitigate local deviations in flow rate, COD, SS, viscosity, and turbidity, and to reduce the occurrence of non-uniformity of properties caused by sedimentation or concentration.

[0048] (3) In the above (1), the artificial intelligence control unit (300) is,

[0049] A properties sensing unit (310) that collects sensing information from sensors installed in an influent properties homogenization tank (5), an anaerobic tank (10), an anoxic tank (20), an aerobic reaction tank (30), a membrane separation unit (40), and a treated water tank (50);

[0050] A process state judgment unit (320) that determines the current process state of each processing tank based on data collected from the above-mentioned shape sensing unit (310);

[0051] A load prediction unit (330) that calculates the expected load to be introduced into the aerobic reaction tank (30) at the rear;

[0052] A stirring condition calculation unit (340) that calculates the rotational speed of the stirrer (100) and the inclination angle of the blade (120) based on information collected from sensors installed in the aerobic reaction tank (30) and the membrane separation unit (40);

[0053] A mixing non-uniformity prediction unit (350) that predicts the possibility of mixing non-uniformity based on information received from a sensor installed in an aerobic reactor (30);

[0054] A process interlocking control unit (360) that controls the operating conditions of an anaerobic tank (10), an anoxic tank (20), an aerobic reactor (30), a membrane separation unit (40), and a treated water tank (50) in an interlocking manner;

[0055] A control signal output unit (370) that outputs the control value calculated by the process linkage control unit (360) and the stirring condition calculation unit (340);

[0056] and an operation data learning unit (380) that updates the operation conditions and process control values ​​of the stirrer (100) by storing and learning the information collected by the above-mentioned shape sensing unit (310), the result of determining the current process state in the process state judgment unit (320), the value calculated in the stirring condition calculation unit (340), and the prediction result in the mixing non-uniformity prediction unit (350);

[0057] An A2 / O-based membrane bioreaction wastewater treatment system characterized by including

[0058] (4) In the above (1),

[0059] The above rotational shaft (110) is composed of a plurality of unit shafts (111) interconnected in series, and

[0060] The above operating shaft (132) is formed by connecting a plurality of unit shafts (132a) in series, and

[0061] The above blade original positioning part (128) includes a torsion spring, and one end of the torsion spring is fixed to the blade shaft (122), and the other end is fixed to the first blade (124) or the second blade (126), characterized in that it is an A2 / O-based membrane bioreaction wastewater treatment system. Effects of the invention

[0063] According to the present invention, by applying a stirrer with an adjustable blade angle, the flow direction and stirring intensity inside the treatment tank can be controlled according to the operating conditions of the wastewater, thereby improving mixing uniformity and reducing the occurrence of local stagnation areas.

[0064] In addition, according to the present invention, by including a structure in which the blade folds and returns according to fluid resistance, it is possible to maintain a stable flow state in response to changes in wastewater viscosity, and to improve mixing efficiency while mitigating excessive flow bias.

[0065] In addition, according to the present invention, since a plurality of blade pieces can each be individually folded and returned, responsiveness to changes in the flow state of wastewater can be improved, and the mixing stability inside the treatment tank can be enhanced. Brief explanation of the drawing

[0066] Figure 1 is an overall configuration diagram of an A2 / O-based membrane bioreaction wastewater treatment system according to the present invention. Figure 2 is an overall configuration diagram of a stirrer according to an embodiment of the present invention. FIG. 3 is a detailed structural diagram of a blade and a blade shaft according to an embodiment of the present invention. FIG. 4 is a structural diagram of a rotation axis and an angle adjustment unit according to an embodiment of the present invention. FIG. 5 is an operating state diagram of a foldable blade according to an embodiment of the present invention. FIG. 6 is a structural diagram of a foldable blade and blade piece according to an embodiment of the present invention. Specific details for implementing the invention

[0067] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0068] Throughout the specification, when a part is described as "comprising" or "including" a component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, the term "...part" as used in the specification refers to a unit that performs at least one function or operation. Additionally, "one (a or an)," "one," "the," and similar related terms may be used in the context describing the invention (particularly in the context of the following claims) to include both singular and plural forms, unless otherwise indicated in the specification or clearly contradicted by the context.

[0069] In describing the embodiments of the present invention, specific descriptions of known functions or configurations will be omitted if it is determined that such detailed descriptions could unnecessarily obscure the essence of the invention. Furthermore, the terms described below are defined in consideration of their functions in the embodiments of the present invention, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification.

[0070] FIG. 1 illustrates the overall configuration of an A2 / O-based membrane bioreaction wastewater treatment system including a variable flow agitator according to one embodiment of the present invention.

[0071] The A2 / O-based membrane bioreaction wastewater treatment system according to the present invention may be configured to include an anaerobic tank (10), an anoxic tank (20), an aerobic reaction tank (30), a membrane separation unit (40), a treated water tank (50), and an artificial intelligence control unit (300) in order to remove organic matter and nitrogen and phosphorus components from the influent wastewater.

[0072] The above anaerobic tank (10) is configured to perform pretreatment of organic matter and phosphorus components contained in the influent wastewater, and is configured to improve the biological phosphorus removal efficiency in subsequent processes by inducing the activation of phosphorus-releasing microorganisms under anaerobic conditions. The influent wastewater may be transferred to an anoxic tank (20) after remaining in the above anaerobic tank (10) for a certain period of time.

[0073] Preferably, an embodiment of the present invention includes an inflow homogenization tank (5) upstream of the anaerobic tank (10).

[0074] The above-mentioned influent homogenization tank (5) is a pretreatment configuration for supplying the influent wastewater to the anaerobic tank (10) after mitigating deviations in flow rate, SS, viscosity, and organic matter concentration, and may include an influent detection sensor (5a) and a selective circulation mixing unit (5b) inside. The influent detection sensor (5a) measures the viscosity, turbidity, and SS concentration of the influent wastewater, and the measured values ​​are transmitted to an artificial intelligence control unit (300) and can be used as preliminary input values ​​for controlling the rotation speed and blade angle of the stirrer (100) installed in the aerobic reactor (30). Accordingly, fluctuations in the influent load are not corrected only by post-control of the stirrer (100), but are predicted and buffered in advance during the pretreatment stage, thereby improving the mixing stability and sludge concentration uniformity of the aerobic reactor (30).

[0075] The above-mentioned selective circulation mixing unit (5b) can be configured to circulate a portion of the mixture inside the inflow homogenization tank (5) to mitigate local deviations in flow rate, COD, SS, viscosity, and turbidity, and to reduce the occurrence of non-uniformity in properties caused by sedimentation or concentration.

[0076] To this end, the selective circulation mixing unit (5b) may include a circulation pump, circulation piping, control valve, and a plurality of discharge nozzles for sucking the internal mixture of the inflow homogenization tank (5) and re-discharging it back into the inflow homogenization tank (5). The plurality of discharge nozzles may be arranged to face different heights or different directions of the inflow homogenization tank (5) to mitigate local deviations in COD, SS, viscosity, and turbidity of the inflow wastewater and to reduce the occurrence of sedimentation or stagnation areas. Additionally, the selective circulation mixing unit (5b) may be configured to be selectively driven or to have the circulation amount variably controlled when the change in viscosity, SS, turbidity, or flow rate measured by the substance detection sensor (5a) is greater than or equal to a reference value, thereby mitigating load fluctuations of the downstream aerobic reaction tank (30).

[0077] In an embodiment of the present invention, the raw water flowing into the anaerobic tank (10) is wastewater that has passed through the homogenization tank (5) for influent characteristics, and may have characteristics such as COD 150 to 600 mg / L, BOD (Biochemical Oxygen Demand, hereinafter BOD) 80 to 350 mg / L, SS 80 to 400 mg / L, total nitrogen (TN) 20 to 80 mg / L, and total phosphorus (TP) 3 to 15 mg / L. The anaerobic tank (10) may be operated so that the dissolved oxygen (DO) is maintained at 0.2 mg / L or less, and the oxidation-reduction potential (ORP) may be maintained in the range of -100 to -300 mV. In addition, the hydraulic retention time of the above anaerobic tank (10) can be set to 0.5 to 2.5 hours, and the activity of phosphorus-releasing microorganisms can be induced under these conditions to improve the phosphorus removal efficiency in the subsequent process.

[0078] The above-mentioned anaerobic tank (20) is configured to denitrify nitrate nitrogen and is configured to perform a denitrification reaction using internally recirculated nitrification mixture and incoming organic matter. The above-mentioned anaerobic tank (20) is maintained at a low dissolved oxygen concentration, and nitrate nitrogen can be reduced to nitrogen gas and removed. The mixture that has passed through the above-mentioned anaerobic tank (20) can be supplied to an aerobic reaction tank (30).

[0079] The above-mentioned anoxic tank (20) may be configured to receive a mixture discharged from the above-mentioned anaerobic tank (10) and a nitrification mixture that is internally recirculated from the aerobic reaction tank (30) or membrane separation unit (40). The influent mixture of the above-mentioned anoxic tank (20) may have a nitrate nitrogen (NO3-N) of 5 to 40 mg / L and a COD of 80 to 400 mg / L, and the dissolved oxygen (DO) may be maintained at 0.5 mg / L or less, preferably 0.1 to 0.3 mg / L. The oxidation-reduction potential (ORP) of the above-mentioned anoxic tank (20) may be maintained in the range of -50 to -200 mV, the hydraulic retention time may be set to 1 to 4 hours, and the internal recirculation ratio may be set in the range of 100 to 400% relative to the influent flow rate.

[0080] The above-mentioned aerobic reactor (30) is a core bioreactor that performs organic matter oxidation and ammoniacal nitrogen nitrification, and is configured to perform aeration and stirring while the activated sludge and wastewater are mixed.

[0081] A stirrer (100) according to the present invention, as shown in FIG. 2, is installed inside the aerobic reaction tank (30), and the stirrer (100) forms a mixed flow inside the treatment tank to improve the uniformity of mixing of the mixed liquid.

[0082] In particular, the above-described stirrer (100) is configured such that the inclination angle of the blade (120) can be adjusted according to changes in the viscosity of the wastewater, MLSS (activated sludge suspended solids, hereinafter MLSS) concentration, and flow rate, thereby reducing local dead zones inside the treatment tank and mitigating sludge concentration deviations. In addition, the blade (120) is configured to maintain a stable mixing state under various operating conditions by performing folding and return movements according to fluid resistance.

[0083] The above aerobic reactor (30) is configured to receive the mixed liquid discharged from the above anoxic tank (20) and to perform organic oxidation and nitrification of ammoniacal nitrogen. The mixed liquid of the above aerobic reactor (30) can be maintained in the range of MLSS 4,000 to 12,000 mg / L and MLVSS (activated sludge suspended volatile solids, hereinafter MLVSS) 2,500 to 8,000 mg / L, and the dissolved oxygen (DO) can be maintained in the range of 1.0 to 4.0 mg / L, the pH in the range of 6.5 to 8.5, and the water temperature in the range of 15 to 35℃. In addition, the hydraulic retention time of the aerobic reactor (30) can be set to 3 to 10 hours, and the sludge retention time can be set to 10 to 40 days, and the stirrer (100) can be operated to adjust the rotational speed and blade inclination angle according to the viscosity of the mixed liquid of 1 to 20 mPa·s and the flow rate fluctuation.

[0084] The above membrane separation unit (40) is configured to separate treated water and activated sludge from the mixed liquid supplied from the above aerobic reactor (30), and is configured to perform solid-liquid separation using a membrane module. The above membrane separation unit (40) is configured to suppress the outflow of suspended solids and microbial flocs and to produce high-quality treated water.

[0085] The membrane separation unit (40) is configured to receive the mixed liquid from the aerobic reactor (30) and perform solid-liquid separation, and may include a microfiltration membrane or an ultrafiltration membrane. The membrane pore size of the membrane separation unit (40) may be in the range of 0.01 to 0.4 μm, the membrane filtration flux may be operated in the range of 5 to 30 LMH, and the transmembrane pressure (TMP) may be maintained in the range of 5 to 60 kPa. In addition, the membrane separation unit (40) may perform periodic suction-stop operation or backwash operation, and may be operated, for example, by suctioning for 5 to 15 minutes and stopping for 0.5 to 2 minutes.

[0086] The above-mentioned treatment tank (50) is configured to store the treated water that has passed through the membrane separation unit (40), and is configured to discharge the treated water to the outside or supply it to a reuse process. If necessary, a sensor for measuring the quality of the treated water may be additionally installed in the above-mentioned treatment tank (50).

[0087] The above-mentioned treatment tank (50) is configured to store treated water that has passed through the membrane separation unit (40), and the treated water may have a water quality such as, for example, BOD 5 mg / L or less, SS 5 mg / L or less, COD 20 mg / L or less, total nitrogen (TN) 10 to 20 mg / L or less, and total phosphorus (TP) 0.2 to 2.0 mg / L or less. The above-mentioned treatment tank (50) may be configured to maintain the pH of the treated water in the range of 6.0 to 8.5, and, if necessary, a sensor may be installed to monitor residual turbidity, electrical conductivity, and whether the discharge water quality standards are met. The treated water stored in the above-mentioned treatment tank (50) may be discharged or supplied as washing water, landscaping water, or process reuse water.

[0088] The artificial intelligence control unit (300) is configured to control the operating state of the agitator (100) according to changes in the characteristics of the wastewater, and is configured to collect and analyze operating state information such as COD, SS, viscosity, flow rate, and MLSS concentration of the wastewater in real time. The artificial intelligence control unit (300) can be configured to maintain the mixing state inside the treatment tank in an optimal state by controlling the rotational speed and blade inclination angle of the agitator (100) according to the analysis results.

[0089] The artificial intelligence control unit (300) above is configured to analyze the operating status of the A2 / O-based membrane bioreaction wastewater treatment system according to the present invention and to control the operating conditions of the anaerobic tank (10), anoxic tank (20), aerobic reaction tank (30), membrane separation unit (40), treatment tank (50), and stirrer (100) in conjunction with each other.

[0090] Preferably, the artificial intelligence control unit (300) may include a shape sensing unit (310), a process state judgment unit (320), a load prediction unit (330), a stirring condition calculation unit (340), a mixing non-uniformity prediction unit (350), a process linkage control unit (360), a control signal output unit (370), and an operation data learning unit (380).

[0091] The above-mentioned properties sensing unit (310) is configured to collect sensing information including water quality and operating status of each treatment stage by being connected to sensors installed in the influent properties homogenization tank (5), anaerobic tank (10), anoxic tank (20), aerobic reaction tank (30), membrane separation unit (40), and treatment tank (50). The above-mentioned properties sensing unit (310) can collect COD, BOD, SS, turbidity, viscosity, flow rate, pH, water temperature, total nitrogen, total phosphorus, dissolved oxygen, redox potential, MLSS, MLVSS, and transmembrane differential pressure of the influent wastewater in real time or periodically. At this time, the viscosity, SS, and flow rate information measured in the influent properties homogenization tank (5) can be used as preliminary input values ​​for controlling the stirrer (100) of the downstream aerobic reaction tank (30).

[0092] The process state judgment unit (320) is configured to determine the current process state of each treatment tank using data collected from the characteristics sensing unit (310). For example, the process state judgment unit (320) can determine whether the dissolved oxygen and redox potential of the anaerobic tank (10) are in a state suitable for biological phosphorus release, determine the denitrification reaction state based on the nitrate nitrogen concentration and ORP of the anoxic tank (20), and determine the mixing and aeration state required for organic matter oxidation and nitrification reactions using DO, MLSS, and viscosity information of the aerobic reaction tank (30). In addition, the process state judgment unit (320) can determine whether the entire process is operating stably by analyzing the transmembrane pressure increase rate of the membrane separation unit (40) and the water quality of the treated water tank (50).

[0093] The load prediction unit (330) is configured to predict the pollution load and flow load to be introduced into the downstream process based on past and present data collected from the inflow homogenization tank (5) and each treatment tank. The load prediction unit (330) can calculate the expected organic load, nitrogen load, and viscosity change to be reached in the aerobic reaction tank (30) by using the hourly change patterns of the inflow flow rate, COD, SS, viscosity, and total nitrogen concentration. Accordingly, the load prediction unit (330) can provide the predicted value to the subsequent control unit so that the rotational speed of the stirrer (100) and the blade inclination angle adjustment are performed in advance when an increase in load is expected.

[0094] The above stirring condition calculation unit (340) is configured to calculate the driving conditions of the stirrer (100) based on the mixing state of the aerobic reactor (30), viscosity, MLSS concentration, DO concentration, and transmembrane differential pressure information of the membrane separation unit (40). The above stirring condition calculation unit (340) can set the rotational speed of the stirrer (100), the inclination angle of the blade (120), and the amount of movement of the operating shaft (132) as control variables. For example, if the mixing non-uniformity increases due to an increase in MLSS concentration or viscosity, the stirring condition calculation unit (340) can calculate control conditions to increase the rotational speed and increase the inclination angle of the blade (120) by moving the operating shaft (132) through the control drive unit (133).

[0095] The above mixing non-uniformity prediction unit (350) is configured to predict the possibility of mixing non-uniformity based on information regarding the MLSS concentration deviation, viscosity, turbidity, and stirring state of the aerobic reactor (30). The above mixing non-uniformity prediction unit (350) can determine that there is a high possibility of a local stagnation area being formed inside the treatment tank if the MLSS deviation measured at multiple points inside the reactor is greater than or equal to a reference value, or if an increase in viscosity and a decrease in flow rate occur simultaneously.

[0096] In addition, the above mixing non-uniformity prediction unit (350) can predict the possibility of deterioration of the mixing state by analyzing the rotation speed, blade inclination angle, and mixing uniformity index of the stirrer (100) together, and if the mixing non-uniformity increases above a reference value, it can transmit a control request to the stirring condition calculation unit (340) and the process linkage control unit (360).

[0097] Accordingly, the process interlocking control unit (360) can control the rotation speed of the stirrer (100) or adjust the angle of inclination of the blade (120) to improve the uniformity of mixing inside the treatment tank.

[0098] The above process interlocking control unit (360) is configured to control the operating conditions of the anaerobic tank (10), anoxic tank (20), aerobic reactor (30), membrane separation unit (40), and treated water tank (50) in an interlocking manner. The above process interlocking control unit (360) can adjust the inflow rate or internal circulation rate when the ORP of the anaerobic tank (10) deviates from the set range, and can adjust the internal return rate from the aerobic reactor (30) to the anoxic tank (20) when the denitrification efficiency of the anoxic tank (20) decreases.

[0099] In addition, if the DO of the aerobic reactor (30) is lower than the target value or the risk of non-uniform mixing increases, the rotation speed and blade inclination angle of the stirrer (100) can be adjusted, and at the same time, the suction operation cycle of the membrane separation unit (40) can be adjusted.

[0100] The above control signal output unit (370) is configured to transmit the control value determined by the process linkage control unit (360) and the stirring condition calculation unit (340) to the actual driving device. The above control signal output unit (370) outputs a rotational speed control signal to the motor driving unit of the stirrer (100) and outputs a movement control signal for the operating shaft (132) to the control driving unit (133). In addition, the control signal output unit (370) is connected to an internal return pump (not shown), an aeration device (not shown), a suction pump (not shown) of the membrane separation unit (40), and a treated water discharge valve (not shown) so that the operating conditions of each device are adjusted according to the process state.

[0101] The above-mentioned operation data learning unit (380) is configured to store and learn the operation data collected from the above-mentioned properties sensing unit (310), the judgment result of the process state judgment unit (320), the control value of the stirring condition calculation unit (340), and the prediction result of the mixing non-uniformity prediction unit (350), thereby updating the optimal operation conditions and process control values ​​of the stirrer (100). The above-mentioned operation data learning unit (380) learns the correlation between changes in inflow load, driving conditions of the stirrer (100), changes in transmembrane differential pressure, and the quality of the treated water, and subsequently calculates the optimal stirring conditions and process operation conditions under the same or similar inflow conditions. Accordingly, the present invention can improve the mixing uniformity and sludge concentration stability of the aerobic reactor (30) as the operating time accumulates.

[0102] In an embodiment of the present invention, the process state judgment unit (320) may calculate a process state index P to quantitatively determine the operating state of each treatment tank. For example, the process state index P may be calculated by assigning weights to the normalized values ​​of the inflow COD, SS, viscosity, MLSS, DO deviation, and ORP deviation, and may be defined by the following formula.

[0103]

[0104] Here is the normalized COD value, is the normalized SS value, is the normalized viscosity value, is the normalized MLSS value, is the deviation value from the target DO, represents the deviation value from the target ORP, and inside represents the weight of each item. The process state judgment unit (320) can determine that the process state index P is above a reference value and is in a high load or unstable operating state.

[0105] The load prediction unit (330) uses inflow characteristic data from the current time and past time to predict the change in inflow load over time, and the predicted load value It can be calculated. For example, the above prediction load value is the current inflow load , immediate inflow load , rate of change in flow rate and viscosity change rate It can be calculated using the following formula.

[0106]

[0107] Here means the COD load or nitrogen load at the current point in time, and inside is a prediction coefficient corrected by the driving data learning unit (380). The load prediction unit (330) can generate a control value to preemptively increase the stirring intensity and aeration conditions of the aerobic reactor (30) when the predicted load value is greater than or equal to the reference value.

[0108] The above stirring condition calculation unit (340) can calculate the rotational speed N and blade inclination angle θ of the stirrer (100) according to the mixing state of the aerobic reactor (30). For example, the above stirring condition calculation unit (340) can calculate control variables so that the following objective function J is minimized.

[0109]

[0110] Here, H represents mixing uniformity, F represents mixing non-uniformity, E represents energy consumption index, and T represents the deviation from the target DO, and inside represents the weight of each item. The stirring condition calculation unit (340) calculates the rotational speed N and blade inclination angle that minimize the objective function J. A combination of can be selected and set as the driving conditions of the stirrer (100).

[0111] The above mixing non-uniformity prediction unit (350) can calculate the mixing non-uniformity F to quantitatively evaluate the mixing state of the aerobic reactor (30). In one embodiment, the mixing non-uniformity F can be defined by the following equation.

[0112]

[0113] Here, ΔMLSS represents the MLSS concentration deviation value measured at multiple locations of the aerobic reactor (30), and is the normalized viscosity value of the mixture, is the normalized turbidity value, is the optimal blade inclination angle under current viscosity, MLSS, and flow rate conditions, represents the deviation from the target inclination angle, N represents the rotational speed of the stirrer (100), and H represents the mixing uniformity index calculated based on the MLSS deviation at multiple points inside the aerobic reactor (30). Also, inside represents a weighting coefficient to reflect the influence of each variable.

[0114] The above mixing non-uniformity prediction unit (350) may determine that there is a high possibility that a sludge concentration deviation or a local stagnation area will be formed inside the treatment tank when the mixing non-uniformity F increases above a reference value. Accordingly, the above process linkage control unit (360) may increase the rotational speed N of the agitator (100) or the inclination angle of the blade (120) optimal slope angle It can be controlled to improve the uniformity of mixing inside the treatment tank by adjusting it to be close to [the value].

[0115] The above process linkage control unit (360) has an internal return ratio based on the status value of each processing tank. , sludge return rate , aeration amount , stirrer rotation speed N and blade inclination angle It can be controlled in conjunction. For example, if the nitrate nitrogen concentration of the anaerobic tank (20) is above a reference value, the internal recirculation ratio Increase the amount of aeration, and if the DO of the aerobic reactor (30) is lower than the target value, the amount of aeration It increases, and if the mixing non-uniformity F is above the reference value, the blade inclination angle It can be controlled to increase the adjustment and rotational speed N.

[0116] The above-mentioned driving data learning unit (380) can correct the weights of each algorithm using the difference between the actual processing result and the predicted result. For example, the driving data learning unit (380) predicts the processing number COD (COD pred ), predicted TMP(predicted membrane differential pressure, TMP pred ) and predicted DO(DO pred The loss function using the error between ) and the actual measured value (meas) It is possible to calculate and update each weight so that the above loss function is reduced.

[0117]

[0118] In the above formula, the subscript 'pred' is used to denote a predicted value, and 'meas' is used to denote a measured value. Accordingly, the artificial intelligence control unit (300) can repeatedly learn the correlation between the change in the characteristics of the influent wastewater, the operating conditions of the agitator (100), the membrane fouling state of the membrane separation unit (40), and the water quality of the treated water, and calculate an optimal process control value under the same or similar operating conditions.

[0119] A portion of the mixture treated inside the aerobic reactor (30) can be recirculated to the anoxic tank (20) through an internal return line, thereby improving the denitrification efficiency of nitrate nitrogen. Additionally, a portion of the activated sludge can be configured to be recirculated to the anaerobic tank (10) or the aerobic reactor (30) through a sludge return line.

[0120] Hereinafter, the contents of the present invention will be described in detail with respect to the stirrer (100) installed inside the aerobic reaction tank (30).

[0121] As shown in FIG. 2, the above-mentioned stirrer (100) is a device installed inside the aerobic reaction tank (30) to receive rotational force and stir a mixture of wastewater and activated sludge, and includes a rotating shaft (110) that transmits rotational force by a rotary drive unit (140) and a plurality of blades (120) coupled to the rotating shaft (110) to form a fluid flow.

[0122] The above-mentioned stirrer (100) is configured to improve the uniformity of mixing of the mixture by forming a mixing flow inside the aerobic reaction tank (30) through rotation. Accordingly, the above-mentioned stirrer (100) can perform the function of reducing the variation in activated sludge concentration inside the aerobic reaction tank (30) and reducing the occurrence of stagnant areas inside the treatment tank.

[0123] As shown in FIGS. 2 and 3, each of the above blades (120) has a blade shaft (122) as its central axis, and the blade shaft (122) is installed to be rotatable on a rotation axis (110).

[0124] Preferably, the blade shaft (122) is installed in the center of the blade (120) and can be rotatably supported with respect to the rotation axis (110) by a bearing. Accordingly, the blade (120) rotates as a whole by the rotation of the rotation axis (110), while the angle of inclination can be adjusted around the blade shaft (122).

[0125] The above-described stirrer (100) further includes an angle adjustment unit (130) that adjusts the inclination angle of the blade (120) by rotating the blade shaft (122). The angle adjustment unit (130) may include an operating space (131), an operating shaft (132), an adjustment drive unit (133), a driven gear (134), a drive block (135), and a rack gear (136).

[0126] The above operating space (131) is formed inside the rotation shaft (110), and the rotation shaft (110) may have a plurality of unit shafts (111) of a certain length connected in series, and in this case, the operating space (131) formed inside each unit shaft (111) may be formed to be in communication with each other.

[0127] The above operating shaft (132) is installed to be movable along the operating space (131) and may be formed as a single unit or may be formed by connecting a plurality of unit shafts (132a) having a certain length in series. The upper end of the above operating shaft (132) may be formed to protrude upward from the rotation axis (110), and the control drive unit (133) is installed adjacent to the upper end of the rotation axis (110) and configured to move the above operating shaft (132) in the longitudinal direction (or vertical direction) of the operating space (131).

[0128] The above-mentioned driven gear (134) is installed at the end of the blade shaft (122) of each blade (120) and can be positioned within the operating space (131) of the rotation axis (110). The above-mentioned driving block (135) is coupled to the operating shaft (132) and moves together with the operating shaft (132), and can be positioned at a location corresponding to each blade (120) installed on the rotation axis (110).

[0129] In the above-mentioned drive block (135), block protrusions (135a) are formed protruding on both sides relative to the driven gear (134), and a rack gear (136) that meshes with the driven gear (134) is formed on the block protrusions (135a).

[0130] As in one embodiment illustrated in FIG. 3, when a plurality of blades (120) are installed radially with respect to a rotation axis (110), a plurality of block protrusions (135a) corresponding to each blade (120) may be formed on the outer circumference of the drive block (135), and a rack gear (136) formed on each block protrusion (135a) may mesh with a corresponding driven gear (134). Accordingly, the inclination angle of the plurality of blades (120) can be adjusted simultaneously or in conjunction by the movement of a single operating shaft (132).

[0131] When examining the operating state of the angle adjustment unit (130) as shown in FIG. 4, when the operating shaft (132) moves along the operating space (131) by the adjustment drive unit (133), the drive block (135) coupled to the operating shaft (132) moves together. At this time, the rack gear (136) of the drive block (135) moves linearly, and the driven gear (134) meshed with the rack gear (136) rotates, and the blade shaft (122) rotates according to the rotation of the driven gear (134), thereby the inclination angle of the blade (120). The stirring direction and stirring intensity of the fluid can be adjusted according to changes in the viscosity, MLSS concentration, flow rate of the wastewater or the viscosity, MLSS concentration, and flow rate of the wastewater.

[0132] In addition, the blade (120) may be configured to variably form a flow state in response to changes in fluid resistance by means of a folding structure of the first blade (124) and the second blade (126). Accordingly, a stable mixing state can be maintained even when changes in the viscosity of wastewater or the flow velocity of the mixed liquid occur, and the formation of local stagnation areas can be reduced.

[0133] Each of the above blades (120) may include a first blade (124), a second blade (126), and a blade original position portion (128), as shown in FIGS. 3 and 5. The first blade (124) and the second blade (126) may be positioned on both sides relative to the blade shaft (122) and may be formed to be foldable according to fluid resistance.

[0134] The above blade original position part (128) is an elastic configuration and performs the function of returning the folded first blade (124) and second blade (126) to an unfolded state (or restoring the position by restoring force).

[0135] Here, the blade return portion (128) uses a torsion spring as shown in FIG. 3 in one embodiment, and one end of the torsion spring is fixed to the blade shaft (122) and the other end is fixed to the first blade (124) or the second blade (126), and is returned to its original position by a force that returns it to its original state after being folded according to the degree of fluid resistance.

[0136] That is, the first blade (124) and the second blade (126) can repeat folding and returning operations based on the blade shaft (122) according to the flow velocity, viscosity, and sludge concentration of the wastewater when the stirrer (100) rotates. Since the flow state inside the treatment tank can be formed more diversely through this folding and returning operation, it can contribute to improving the uniformity of mixing inside the aerobic reaction tank (30) and reducing localized sludge deposition.

[0137] Additionally, as illustrated in FIG. 6, the first blade (124) and the second blade (126) may be composed of a plurality of first blade segments (125) and second blade segments (127). Each of the plurality of first blade segments (125) and second blade segments (127) is formed to be individually foldable and can be returned to its original state by the blade original position part (128). Accordingly, instead of the entire blade being deformed uniformly, individual folding and return can be performed for each part where fluid resistance acts significantly, thereby improving responsiveness to changes in wastewater characteristics.

[0138] In this way, the stirrer (100) of the present invention can variably form a mixed flow inside a treatment tank by means of a combination of a rotating shaft (110), a blade (120), an angle adjustment part (130), a first blade (124), a second blade (126), and a first blade piece (125) and a second blade piece (127). Accordingly, the present invention can improve the uniformity of mixing inside an aerobic reaction tank (30) and reduce sludge concentration variation and the occurrence of local stagnation areas.

[0139] Hereinafter, the operating conditions and treatment results of an A2 / O-based membrane bioreaction wastewater treatment system including a variable flow agitator according to an embodiment of the present invention are described in more detail. However, the following embodiments are merely examples to aid in understanding the present invention, and the scope of the present invention is not limited thereto.

[0140] [Example]

[0141] In this embodiment, an A2 / O-based membrane bioreactor wastewater treatment system was operated on an influent wastewater mixed with domestic sewage and some high-concentration organic wastewater. The influent wastewater was set to have a COD of 420 mg / L, a BOD of 230 mg / L, an SS of 260 mg / L, a total nitrogen (TN) of 48 mg / L, and a total phosphorus (TP) of 7.2 mg / L.

[0142] First, the influent wastewater was supplied to the influent homogenization tank (5), and in the influent homogenization tank (5), slow mixing was performed for 40 minutes at a stirring speed of 45 rpm. During this process, the flow rate and concentration deviation of the wastewater were mitigated, and changes in viscosity 6.5 mPa·s, turbidity 185 NTU, and SS concentration were measured in real time through the characteristic detection sensor (5a).

[0143] Subsequently, the wastewater was supplied to an anaerobic tank (10), and the anaerobic tank (10) was operated under conditions of dissolved oxygen (DO) 0.1 mg / L or less, ORP -220 mV, and hydraulic retention time (HRT) 1.5 hours. In the anaerobic tank (10), the activation of phosphorus-releasing microorganisms was induced to improve the biological phosphorus removal efficiency in subsequent processes.

[0144] The mixture that passed through the above anaerobic tank (10) was transferred to an anoxic tank (20), and the anoxic tank (20) was operated under conditions of dissolved oxygen (DO) 0.2 mg / L, ORP -120 mV, and hydraulic retention time (HRT) 2.5 hours. In addition, the internal recirculation ratio was set to 250% of the inflow rate to ensure that the denitrification reaction of nitrate nitrogen proceeds smoothly.

[0145] The mixture that passed through the above-mentioned anoxic tank (20) was supplied to the aerobic reactor (30). The above-mentioned aerobic reactor (30) was operated under conditions of MLSS 8,500 mg / L, MLVSS 5,900 mg / L, dissolved oxygen (DO) 2.3 mg / L, pH 7.1, and water temperature 24℃. In addition, the hydraulic retention time (HRT) was maintained at 6 hours and the sludge retention time (SRT) at 25 days.

[0146] A stirrer (100) according to the present invention is installed inside the above-mentioned aerobic reactor (30), and the rotational speed of the stirrer (100) is basically set to 120 rpm. In addition, the artificial intelligence control unit (300) is configured to variably control the rotational speed in the range of 90 to 180 rpm according to changes in the viscosity and MLSS concentration of the mixed liquid. The basic inclination angle of the blade (120) is set to 32°, and is set to increase up to a maximum of 48° when the viscosity increases.

[0147] In particular, the first blade (124) and the second blade (126) of the above-mentioned stirrer (100) are manufactured to consist of a plurality of blade pieces (125, 127) and are configured to be partially folded according to fluid resistance when the viscosity of the mixed liquid increases, thereby mitigating excessive flow bias while maintaining a stable mixing state.

[0148] The above membrane separation unit (40) used an ultrafiltration membrane with a pore size of 0.08 μm, and was operated under conditions of a membrane filtration flux of 18 LMH and a transmembrane pressure difference (TMP) of 24 kPa. In addition, the membrane separation unit (40) repeated a 10-minute suction followed by a 1-minute stop operation to maintain a stable membrane filtration state.

[0149] As a result, it was confirmed that the A2 / O-based membrane bioreaction wastewater treatment system according to the present embodiment improved the efficiency of organic matter removal and nitrogen and phosphorus removal, improved mixing uniformity, and reduced sludge concentration variation and stagnation zones.

[0150] Changes in influent and treated water quality division Inflow water treated water COD (mg / L) 420 14 BOD (mg / L) 230 3 SS (mg / L) 260 2 Total Nitrogen (TN) (mg / L) 48 9 Total Phosphorus (TP) (mg / L) 7.2 0.4 Turbidity (NTU) 185 0.9

[0151] In addition, in this embodiment, to compare the variable mixing control effect according to the variable flow control of the stirrer (100), the operation results were compared with a comparative example in which a fixed-blade stirrer was applied.

[0152] In the comparative example, instead of the stirrer (100) of the present invention, a general propeller-type stirrer with a fixed blade angle was installed in the aerobic reactor (30) and operated under the same conditions. The stirrer of the comparative example did not include a blade angle adjustment function or a foldable blade structure, and the rotational speed was fixed at 120 rpm. In addition, the influent water characteristics, aeration conditions, MLSS concentration, hydraulic retention time (HRT), and membrane separation conditions were maintained identically to the embodiment of the present invention. The mixing uniformity index was calculated based on the MLSS deviation at multiple points inside the reactor.

[0153] Comparison of operating performance based on stirrer structure division Examples of the present invention Comparative example Mixing uniformity index 0.93 0.74 Sludge concentration deviation Very low height Frequency of occurrence of stagnation areas Very low height Stirring stability excellence commonly Responsiveness to viscosity changes excellence lowness

[0154] From the above results, it was confirmed that the stirrer (100) according to the present invention is effective in actively responding to changes in the viscosity and load of the mixed liquid to improve the mixing uniformity of the aerobic reactor (30) and to reduce the variation in sludge concentration and the occurrence of stagnant areas.

[0155] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0156] 5 : Inflow Characteristic Homogenization Tank 5a : Characteristic Detection Sensor 5b : Selective Circulation Mixing Unit 10 : Anaerobic Tank 20 : Anoxic Tank 30 : Aerobic Reactor 40 : Membrane Separation Unit 50 : Treatment Tank 100 : Stirrer 110 : Rotating Shaft 120 : Blade 122 : Blade Shaft 124 : First Blade 125 : First Blade Segment 126 : Second Blade 127 : Second Blade Segment 128 : Blade Return Unit 130 : Angle Adjustment Unit 131 : Operating Space 132 : Operating Shaft 133 : Control Drive Unit 134 : Driven Gear 135 : Drive Block 135a : Block Protrusion 136 : Rack Gear 300 : Artificial Intelligence Control Unit 310 : Characteristic Sensing Unit 320 : Process State Judgment Unit 330 : Load Prediction Unit 340 : Stirring Condition Calculation Unit 350 : Mixing Non-uniformity Prediction Unit 360 : Process Interlock Control Unit 370 : Control Signal Output Unit 380 : Operation Data Learning Unit

Claims

Claim 1 A2 / O-based membrane bioreaction wastewater treatment system for removing organic matter and nitrogen / phosphorus components contained in influent wastewater, comprising: an anaerobic tank (10) for performing pretreatment of organic matter and phosphorus components contained in influent wastewater; an anoxic tank (20) for performing a denitrification reaction on a mixture that has passed through the anaerobic tank (10); an aerobic reactor (30) equipped with an internal stirrer (100) and for performing organic matter oxidation and nitrification reactions on a mixture that has passed through the anoxic tank (20); a membrane separation unit (40) for separating treated water and activated sludge from the mixture of the aerobic reactor (30); and a treated water tank (50) for storing the treated water that has passed through the membrane separation unit (40). It includes an artificial intelligence control unit (300) that controls the operating state of the stirrer (100) according to changes in the characteristics of the wastewater, and the stirrer (100) comprises: a rotating shaft (110) that transmits rotational force; and a plurality of blades (120) coupled to the rotating shaft (110) to form a fluid flow. and a rotary drive unit (140) for rotating a plurality of blades by rotating the rotary shaft (110); wherein the blade (120) has a blade shaft (122) as a central axis, and the blade shaft (122) is installed to be rotatable with respect to the rotary shaft (110); and the stirrer (100) includes an angle adjustment unit (130) for adjusting the inclination angle of the blade (120), wherein the angle adjustment unit (130) comprises: an operating space (131) formed inside the rotary shaft (110); an operating shaft (132) installed to be movable along the operating space (131); an adjustment drive unit (133) for moving the operating shaft (132) in the longitudinal direction of the operating space; a driven gear (134) installed at the end of the blade shaft (122) to rotate the blade shaft; a drive block (135) coupled to the operating shaft (132) and moving together; and the A rack gear (136) formed in the drive block (135) to mesh with the driven gear (134);The apparatus includes, wherein the blade (120) comprises: a first blade (124) and a second blade (126) formed to be foldable and arranged on both sides relative to the blade shaft (122); and a blade return section (128) for returning the folded first blade (124) and second blade (126) to an unfolded state; wherein the first blade (124) and the second blade (126) are each composed of a first blade section (125) and a second blade section (127) that are segmented into multiple parts and individually formed to be foldable, and the apparatus includes an inflow homogenization tank (5) at the front end of the anaerobic tank (10), wherein the inflow homogenization tank (5) comprises a composition detection sensor (5a) for measuring the viscosity, turbidity, and SS concentration of the inflow wastewater, and a component that circulates a portion of the mixed liquid inside the inflow homogenization tank (5) to measure the flow rate, COD, SS, viscosity, and turbidity An A2 / O-based membrane bioreaction wastewater treatment system characterized by including a selective circulation mixing unit (5b) that mitigates local deviations and reduces the occurrence of non-uniformity of properties due to sedimentation or concentration. Claim 2 delete Claim 3 delete Claim 4 delete

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