Water treatment system using division supply of influent to anoxic tank and method for operating the same

Abstract

According to the present invention, there is provided an anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on anaerobic effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on anaerobic effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank that selectively operates under one of aerobic conditions and anoxic tank conditions for the aerobic effluent discharged from the aerobic tank; a membrane tank equipped with a membrane filtration device that filters and treats the intermittent aeration tank effluent discharged from the intermittent aeration tank; a treated water EC sensor that measures the electrical conductivity of the treated water discharged from the membrane filtration device; a degassing tank that lowers the dissolved oxygen concentration of the membrane tank effluent discharged from the membrane tank and removes nitrogen and phosphorus; and a water to be treated split injection unit that split-injects the water to be treated into the anoxic tank. A water treatment system is provided that includes a control unit that controls the operation of a split injection unit for the water to be treated using the measured value of the treated water EC measured by the treated water EC sensor.

Description

Technology Field

[0001] The present invention relates to water treatment technology, and more specifically, to a technology that improves nitrogen removal performance and phosphorus removal performance by splitting and injecting influent water. Background Technology

[0002] As a technology related to the present invention, Korean Patent Publication No. 10-2024-0060438 describes a configuration in which, in a wastewater treatment facility equipped with an anoxic tank, an anaerobic tank, an aerobic tank, an alternating reaction tank, a membrane tank, and a degassing tank, the divided injection of influent water into the degassing tank is controlled by comparing the dissolved oxygen concentration in the degassing tank with a set dissolved oxygen concentration, and the supply of a coagulant for treating phosphorus is controlled by comparing the total phosphorus concentration in the treated water with a set total phosphorus concentration, thereby improving phosphorus removal efficiency. In the aforementioned prior art document, a NO3-N sensor for measuring nitrate nitrogen (NO3-N) in the treated water is provided, and NO3 - -N sensors can result in inaccurate measurements due to factors such as suspended solids and turbidity in wastewater, and since they are expensive, they are disadvantageous in terms of maintenance; therefore, technology is required to improve this. Prior art literature

[0003] Republic of Korea Published Patent Application No. 10-2024-0060438 (May 8, 2024) The problem to be solved

[0004] The objective of the present invention is to provide a water treatment system and a method of operating the same that improves nitrogen removal performance and phosphorus removal performance by splitting the influent water into an anaerobic tank. means of solving the problem

[0005] To achieve the above-mentioned objective of the present invention, according to one aspect of the present invention, therein comprises: an anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on anoxic tank effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on anoxic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank selectively operated under one of aerobic conditions and anoxic tank conditions for aerobic tank effluent discharged from the aerobic tank; a membrane tank equipped with a membrane filtration device for filtering and treating intermittent aeration tank effluent discharged from the intermittent aeration tank; a treated water EC sensor for measuring the electrical conductivity of the treated water discharged from the membrane filtration device; and a degassing tank for lowering the dissolved oxygen concentration of membrane tank effluent discharged from the membrane tank and removing nitrogen and phosphorus. A water treatment system is provided comprising: a divided injection unit for dividing and injecting the water to be treated into the anaerobic tank; and a control unit for controlling the operation of the divided injection unit for the water to be treated using the measured value of the treated water EC measured by the treated water EC sensor.

[0006] delete

[0007] To achieve the above-mentioned objective of the present invention, according to another aspect of the present invention, therein comprises: an anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on anoxic tank effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on anoxic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank selectively operated under one of aerobic conditions and anoxic tank conditions for aerobic tank effluent discharged from the aerobic tank; an intermittent aeration tank blower for supplying air to the intermittent aeration tank; a membrane tank equipped with a membrane filtration device for filtering and treating intermittent aeration tank effluent discharged from the intermittent aeration tank; a treated water EC sensor for measuring the electrical conductivity (EC) of the treated water discharged from the membrane filtration device; and a A method of operating a water treatment system comprising: a degassing tank for lowering the dissolved oxygen concentration of the effluent from a membrane tank and removing nitrogen and phosphorus; a divided injection unit for dividing and injecting the water to be treated into an anoxic tank; and a control unit for controlling the operation of the divided injection unit for the water to be treated, wherein the control unit confirms the measured value of the treated water EC measured by the treated water EC sensor; a nitrate nitrogen concentration estimation step in which the control unit estimates the nitrate nitrogen concentration of the treated water using the measured value of the treated water EC and calculates an estimated value of the treated water nitrate nitrogen concentration; an organic matter requirement calculation step in which the control unit calculates the optimal organic matter requirement for removing nitrate nitrogen from the treated water according to the estimated value of the treated water nitrate nitrogen concentration; and an influent distribution amount calculation step in which the control unit calculates the injection amount of the water to be treated according to the optimal organic matter requirement.A method of operating a water treatment system is provided, comprising an influent water injection step in which the control unit controls the operation of the water split injection unit so that the water to be treated is injected into the anoxic tank according to the injection amount of the water to be treated, and the nitrate nitrogen concentration estimation step is performed by the control unit calculating the nitrate nitrogen concentration estimation value using the EC measurement value of the treated water based on the correlation between the nitrate nitrogen and the electrical conductivity of the treated water.

[0008] To achieve the above-mentioned objective of the present invention, according to another aspect of the present invention, therein comprises: an anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on anoxic tank effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on anoxic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank selectively operated under one of aerobic conditions and anoxic tank conditions for aerobic tank effluent discharged from the aerobic tank; an intermittent aeration tank blower for supplying air to the intermittent aeration tank; a membrane tank equipped with a membrane filtration device for filtering and treating intermittent aeration tank effluent discharged from the intermittent aeration tank; and a degassing tank for lowering the dissolved oxygen concentration and removing nitrogen and phosphorus from membrane tank effluent discharged from the membrane tank. A water treatment system is provided, comprising: a water split injection unit for splitting and injecting the water to be treated into the anoxic tank, the anaerobic tank, and the degassing tank; an internal return unit for returning the degassing tank effluent discharged from the degassing tank to the anoxic tank, the intermittent aeration tank, and the membrane tank; and a control unit for controlling the operation of the intermittent aeration tank blower, the water split injection unit, and the internal return unit. Effects of the invention

[0009] According to the present invention, all the objectives of the present invention described above can be achieved. Specifically, since the nitrate nitrogen in the treated water is estimated from the EC measurement value of the treated water measured by an EC sensor based on the correlation between nitrate nitrogen and electrical conductivity, even if a nitrate nitrogen sensor is not provided or a problem occurs with the nitrate nitrogen measuring system, organic matter is efficiently supplied to the anoxic tank by injecting the influent water according to the EC measurement value of the treated water, thereby maximizing the utilization of organic matter in the influent water in the anaerobic tank downstream of the anoxic tank, and thus the phosphorus removal performance can be improved by maximizing phosphorus release efficiency. Brief explanation of the drawing

[0010] FIG. 1 is a block diagram schematically illustrating the overall configuration of a water treatment system according to one embodiment of the present invention. FIG. 2 is a flowchart schematically explaining the operation method of a water treatment system according to one embodiment of the present invention. FIG. 3 is a block diagram schematically illustrating the overall configuration of a water treatment system according to another embodiment of the present invention. Specific details for implementing the invention

[0011] Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] FIG. 1 is a block diagram schematically illustrating the overall configuration of a water treatment system according to one embodiment of the present invention. Referring to FIG. 1, a water treatment system (200) according to one embodiment of the present invention comprises: a screen device (105) for removing foreign substances such as impurities from raw water (W0) to be treated; a pretreatment device (110) for removing fibers such as hair from water to be treated (W01) discharged from the screen device (105); a flow rate adjustment tank (115) for storing water to be treated (W02) discharged from the pretreatment device (110) and adjusting the flow rate to discharge it; an anoxic tank (120) for performing denitrification on water to be treated (W1) discharged from the flow rate adjustment tank (115); an anaerobic tank (125) for releasing phosphorus from an anaerobic tank effluent (W2) discharged from the anoxic tank (120); an aerobic tank (130) for performing nitrification and excessive phosphorus uptake on anaerobic tank effluent (W3) discharged from the anaerobic tank (125); and to the aerobic tank (130). An aerobic tank blower (132) that supplies air, an intermittent aeration tank (135) that is selectively operated under one of aerobic and anaerobic conditions for the aerobic tank effluent (W4) discharged from the aerobic tank (130), an intermittent aeration tank blower (137) that supplies air to the intermittent aeration tank (135), a membrane tank (140) that produces treated water (W6) by performing membrane filtration on the intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135), a membrane tank blower (143) that supplies air to the membrane tank (140), a degassing tank (145) that lowers the dissolved oxygen concentration of the membrane tank effluent (W7) discharged from the membrane tank (140) and removes nitrogen and phosphorus, an external carbon source tank (148) that injects organic matter insufficient for removing nitrogen and phosphorus into the degassing tank (145), and A treatment target water split injection unit (150) that splits and injects the treatment target water (W1) discharged from the flow rate adjustment tank (115) into an anoxic tank (120), an anaerobic tank (125), and a degassing tank (145), andIt includes an internal return unit (155) that returns degassing tank effluent (W8) discharged from a degassing tank (145) to an intermittent aeration tank (135) and a membrane tank (140), a sludge return unit (155a) that returns degassing tank effluent (W8) discharged from a degassing tank (145) to an anoxic tank (120), a chemical supply unit (165) that supplies chemicals to an aerobic tank (130), a treated water EC sensor (179) that measures the electrical conductivity (EC) of the treated water (W6), and a control unit (190) that controls the operation of a divided injection unit (150) to control the divided injection amount of the treated water (W1) to the anoxic tank (120).

[0013] The screen device (105) removes foreign substances, such as impurities, from the raw water (W0) to be treated. Since the screen device (105) includes the configuration of a screen device commonly used in the field of water treatment technology, a detailed description thereof is omitted here. The water to be treated (W01) discharged from the screen device (105) flows into the pretreatment device (110).

[0014] The pretreatment device (110) removes hair-like fibers from the water to be treated (W01) discharged from the screen device (105). The water to be treated (W02) discharged from the pretreatment device (110) flows into the flow rate adjustment tank (115).

[0015] The flow rate adjustment tank (115) stores the water to be treated (W02) discharged from the pretreatment device (110) and discharges it at a suitable flow rate corresponding to the treatment capacity of the water treatment system (100). The water to be treated (W1) discharged from the flow rate adjustment tank (115) is divided and injected into the anoxic tank (120), anaerobic tank (125), and degassing tank (145) by the water to be treated split injection unit (150).

[0016] In the anoxic tank (120), denitrification is performed on the water to be treated (W1) discharged from the flow rate adjustment tank (115). In the anoxic tank (120), the water to be treated (W1), which is discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150), and the return water (W8), which is returned from the degassing tank (145) by the internal return unit (155), are introduced. The amount of water to be treated (W1) divided and injected into the anoxic tank (120) is controlled by the control unit (190) of the water to be treated split injection unit (150) so that only the optimal amount required for denitrification is injected. In the anoxic tank (120), denitrification microorganisms release nitrogen gas through denitrification using organic matter contained in the water to be treated (W1) and the return water (W8) under anoxic conditions. The denitrifying microorganisms of the anaerobic tank (120) convert nitrate nitrogen or nitrite nitrogen into nitrogen gas by consuming nitrate nitrogen or nitrite nitrogen as electron acceptors, and consume organic matter as electron donors for denitrification. The anaerobic tank effluent (W2) discharged from the anaerobic tank (120) flows into the anaerobic tank (125).

[0017] In the anaerobic tank (125), phosphorus release occurs from the anaerobic tank effluent (W2) discharged from the anoxic tank (120). The anaerobic tank (125) receives the anaerobic tank effluent (W2) discharged from the anoxic tank (120) and the water to be treated (W1) discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150). In the anaerobic tank (125), phosphorus-accumulating microorganisms consume organic matter contained in the anoxic tank effluent (W2) under anaerobic conditions to form storage substances such as PHB (Polyhydroxybutyrates) or PHA (Polyhydroxyalkanates). The phosphorus-accumulating microorganisms release phosphorus contained in ATP (Adenosine Triphosphate) or polyphosphate to obtain the energy required for the formation of the storage substances. The anaerobic tank wastewater (W3) discharged from the anaerobic tank (125) flows into the aerobic tank (130). Since only the optimal amount of water to be treated (W1) is injected into the anoxic tank (120) for denitrification, the organic matter in the water to be treated (W1) in the anaerobic tank (125) can be utilized to the maximum extent, and accordingly, the phosphorus release efficiency is maximized, thereby improving the phosphorus removal performance.

[0018] In the aerobic tank (130), nitrification and excessive phosphorus intake of the anaerobic tank effluent (W3) discharged from the anaerobic tank (125) take place. The anaerobic tank effluent (W3) discharged from the anaerobic tank (125) flows into the aerobic tank (130). In the aerobic tank (130), phosphorus-accumulating microorganisms oxidize phosphorus within their bodies under aerobic conditions and excessively consume the phosphorus contained in the anaerobic tank effluent (W3), and nitrifying microorganisms oxidize the nitrogen contained in the anaerobic tank effluent (W3) and convert it into nitrate nitrogen. The aerobic tank (130) receives oxygen from the aerobic tank blower (132). Although not illustrated, the aerobic tank (130) is equipped with an air diffuser. The aerobic tank effluent (W4) discharged from the aerobic tank (130) flows into the intermittent aeration tank (135). In the aeration tank (130), a chemical is supplied by the supply unit (165) for the treatment of phosphorus (P).

[0019] The aeration tank blower (132) supplies air to the diffuser provided in the aeration tank (130) through the aeration tank air supply line (133). The operation of the aeration tank blower (132) is controlled by the control unit (190).

[0020] The intermittent aeration tank (135) is selectively operated under one of two conditions: aerobic conditions and anaerobic conditions, for the aerobic tank discharge water (W4) discharged from the aerobic tank (130). The aerobic tank discharge water (W4) discharged from the aerobic tank (130) and the return water (W8) returned from the degassing tank (145) by the internal return unit (155) are introduced into the intermittent aeration tank (135). Although not illustrated, the intermittent aeration tank (135) is equipped with an air diffuser. When air is supplied through the air diffuser (not illustrated) provided in the intermittent aeration tank (135), the intermittent aeration tank (135) functions as an aerobic tank, and when air is not supplied through the air diffuser (not illustrated) provided in the intermittent aeration tank (135), the intermittent aeration tank (135) functions as an anaerobic tank. The function of the intermittent aeration tank (135) depends on the operating state of the intermittent aeration tank blower (137). The intermittent aeration tank discharge water (W5) discharged from the intermittent aeration tank (135) flows into the membrane tank (140).

[0021] The intermittent aeration tank blower (137) supplies air to the diffuser provided in the intermittent aeration tank (135) through the intermittent aeration tank air supply line (138). The operation of the intermittent aeration tank blower (137) is controlled by the control unit (190).

[0022] The membrane tank (140) produces treated water (W6) by performing membrane filtration on the intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135). The intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135) and the return water (W8) returned from the degassing tank (145) by the internal return unit (155) are introduced into the membrane tank (140). The membrane tank (140) receives air from the membrane tank blower (143). The membrane tank (140) is equipped with a membrane filtration device (142) that filters and treats the intermittent aeration tank effluent (W5). The membrane filtration device (142) discharges the treated water (W6) as effluent. Since the membrane filtration device (142) includes a commonly used configuration, a detailed description thereof is omitted here. The membrane tank discharge water (W7) discharged from the membrane tank (140) flows into the degassing tank (190).

[0023] The membrane blower (143) supplies air to the membrane (140). The operation of the membrane blower (143) is controlled by the control unit (190).

[0024] The degassing tank (145) lowers the dissolved oxygen concentration of the membrane tank effluent (W7) discharged from the membrane tank (140) and removes nitrogen and phosphorus. Accordingly, the DO concentration of the return water (W8) discharged from the degassing tank (145) and flowing into the anoxic tank (120) is lowered, thereby improving the denitrification effect in the anoxic tank (120) and the phosphorus release effect in the anaerobic tank (150). The membrane tank effluent (W7) discharged from the membrane tank (140) and the water to be treated (W1) discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150) are introduced into the degassing tank (145). The degassing tank effluent (W8) discharged from the degassing tank (145) is returned to the intermittent aeration tank (135) and the membrane tank (140) by the internal return unit (155), and returned to the anoxic tank (120) by the sludge return unit (155a). The degassing tank (145) receives organic matter from the external carbon source tank (148). The degassing performance of the degassing tank (145) is improved by the organic matter contained in the water to be treated (W1) which is divided and injected into the degassing tank (145) by the water to be treated divided injection unit (150) and the organic matter supplied to the degassing tank (145) from the external carbon source tank (148).

[0025] The external carbon source (148) injects organic matter, which is insufficient for the removal of nitrogen and phosphorus, into the degassing tank (145). The operation of the external carbon source (148) is controlled by the control unit (190).

[0026] The treatment target water split injection unit (150) splits and injects the treatment target water (W1) discharged from the flow rate adjustment tank (115) into an anoxic tank (120), an anaerobic tank (125), and a degassing tank (145). The treatment target water split injection unit (150) is equipped with an injection pump (151) that transports the treatment target water (W1) discharged from the flow rate adjustment tank (115), an anoxic tank injection control valve (152) that controls the injection of the treatment target water (W1) into the anoxic tank (120), an anaerobic tank injection control valve (153) that controls the injection of the treatment target water (W1) into the anaerobic tank (125), and a degassing tank injection control valve (154) that controls the injection of the treatment target water (W1) into the degassing tank (120).

[0027] The injection pump (151) transfers the water to be treated (W1) discharged from the flow rate adjustment tank (115) through the main injection line (150a).

[0028] An anaerobic tank injection control valve (152) is installed in an anaerobic tank injection line (150b) that branches off from the main injection line (150a) and communicates with the anaerobic tank (120), thereby controlling the injection of the water to be treated (W1) into the anaerobic tank (120). The ON / OFF operation of the anaerobic tank injection control valve (152) is controlled by the control unit (190).

[0029] The anaerobic tank injection control valve (153) is installed in the anaerobic tank injection line (150c), which branches off from the main injection line (150a) and communicates with the anaerobic tank (125), to control the injection of the water to be treated (W1) into the anaerobic tank (125). The ON / OFF operation of the anaerobic tank injection control valve (153) is controlled by the control unit (190).

[0030] The degassing tank injection control valve (154) is installed in the degassing tank injection line (150d), which branches off from the main injection line (150a) and communicates with the degassing tank (145), thereby controlling the injection of the water to be treated (W1) into the degassing tank (145). The ON / OFF operation of the degassing tank injection control valve (154) is controlled by the control unit (190).

[0031] The internal return unit (155) returns the degassed tank discharge water (W8) discharged from the degassed tank (145) to the intermittent aeration tank (135) and the membrane tank (140), respectively. The internal return unit (155) is equipped with an internal return pump (156) for transporting the degassed tank discharge water (W8) discharged from the degassed tank (145), an intermittent aeration tank return control valve (158) for controlling the return of the degassed tank discharge water (W8) to the intermittent aeration tank (135), and a membrane tank return control valve (159) for controlling the return of the degassed tank discharge water (W8) to the membrane tank (140).

[0032] The internal return pump (156) transfers the degassing tank wastewater (W8) discharged from the degassing tank (145) to the intermittent aeration tank (135) and the membrane tank (140) through the internal return line (157).

[0033] The intermittent aeration tank return control valve (158) is installed in the internal return line (157) to control the injection of degassing tank discharge water (W8) into the intermittent aeration tank (135). The ON / OFF operation of the intermittent aeration tank return control valve (158) is controlled by the control unit (190).

[0034] The membrane tank return control valve (159) is installed in the internal return line (157) to control the return of the degassing tank discharge water (W8) to the membrane tank (140). The ON / OFF operation of the membrane tank return control valve (159) is controlled by the control unit (190).

[0035] The sludge return unit (155a) returns the degassing tank effluent (W8) discharged from the degassing tank (145) to the anoxic tank (120). The sludge return unit (155a) is equipped with a sludge return pump (156a) that transports the degassing tank effluent (W8) discharged from the degassing tank (145), and an anoxic tank return control valve (158a) that controls the return of the degassing tank effluent (W8) to the anoxic tank (120).

[0036] The sludge return pump (156a) transfers the degassing tank effluent (W8) discharged from the degassing tank (145) to the anoxic tank (120) through the sludge return line (155b).

[0037] The anoxic tank return control valve (158a) is installed in the sludge return line (155b) to control the return of the degassing tank effluent (W8) to the anoxic tank (120). The ON / OFF operation of the anoxic tank return control valve (158a) is controlled by the control unit (190).

[0038] The chemical supply unit (165) supplies a chemical for treating phosphorus (P) to the aerobic tank (130). The chemical supply unit (165) is equipped with a chemical storage tank (166) in which a coagulant, which is a chemical for treating phosphorus (P), is stored, and a line mixer (167) that mixes the chemical with the return water (W8) flowing into the aerobic tank (130). The chemical supply unit (165) supplies the chemical according to the total phosphorus (TP) concentration of the treated water (W6). The operation of the chemical supply unit (165) is controlled by the control unit (190).

[0039] The chemical storage tank (166) stores a coagulant, which is a chemical for treating phosphorus (P). The coagulant stored in the chemical storage tank (166) is supplied to the line mixer (167).

[0040] The line mixer (167) mixes the coagulant supplied from the chemical storage tank (166) with the return water (W8) flowing into the aerobic tank (130).

[0041] The treated water EC sensor (179) measures the electrical conductivity (EC) of the treated water (W6) in real time. The EC of the treated water (W6) measured by the treated water EC sensor (179) is transmitted to the control unit (190) and used to control the operation of the divided injection unit (150) for the treated water.

[0042] delete

[0043] The control unit (190) controls the treatment target water split injection unit (150) to regulate the amount of treatment target water (W1), which is the inflow water, that is split and injected into the anaerobic tank (120). To control the operation of the treatment target water split injection unit (150), the control unit (190) uses the electrical conductivity (EC) of the treatment water (W6) measured by the treatment water EC sensor (179). The specific operation control of the treatment target water split injection unit (150) by the control unit (190) is explained in detail with reference to the flowchart shown in FIG. 2.

[0044] FIG. 2 is a flowchart schematically illustrating a method of operating a water treatment system according to one embodiment of the present invention. The method of operating a water treatment system illustrated in FIG. 2 is a method of operating a water treatment system (100) illustrated in FIG. 1. Referring to FIG. 2 together with FIG. 1, the method of operating a water treatment system according to an embodiment of the present invention comprises: a step of verifying a treated water EC value (S120) in which a control unit (190) verifies a treated water EC value measured by a treated water EC sensor (179); a step of estimating a nitrate nitrogen concentration (S130) in which the control unit (190) estimates the nitrate nitrogen concentration of the treated water (W6) using the treated water EC value verified through the step of verifying the treated water EC value (S120) based on the correlation between nitrate nitrogen and EC, and calculates an estimated value of the treated water nitrate nitrogen concentration; and a step of calculating an organic matter requirement (S140) in which the control unit (190) calculates an optimal organic matter requirement for removing nitrate nitrogen in the treated water according to the estimated value of the treated water nitrate nitrogen concentration estimated through the step of estimating the nitrate nitrogen concentration (S130). The control unit (190) includes an influent water distribution amount calculation step (S150) in which the control unit (190) calculates the amount of water to be injected from the water to be treated (W1) into the anoxic tank (120), and an influent water injection step (S160) in which the control unit (190) controls the water to be treated split injection unit (150) so that the water to be treated (W1) is injected into the anoxic tank (120) according to the injection amount calculated in the influent water distribution amount calculation step (S150).

[0045] delete

[0046] In the step of verifying the treated water EC value (S120), the treated water EC value is verified. The step of verifying the treated water EC value (S120) is performed by the control unit (190) verifying the treated water EC value measured by the treated water EC sensor (179). The treated water EC value verified in the step of verifying the treated water EC value (S120) is used in the step of estimating the nitrate nitrogen concentration (S130).

[0047] In the nitrate nitrogen concentration estimation step (S130), an estimated value of the nitrate nitrogen concentration in the treated water is calculated. In the nitrate nitrogen concentration estimation step (S130), the control unit (190) calculates the nitrate nitrogen (NO3 - Based on the correlation between -N) and EC, the process is performed by estimating the nitrate nitrogen concentration of the treated water (W6) using the treated water EC measurement value confirmed through the treated water EC measurement value confirmation step (S120) and calculating the estimated value of the treated water nitrate nitrogen concentration. The estimated value of the treated water nitrate nitrogen concentration calculated through the nitrate nitrogen concentration estimation step (S130) is used in the organic matter requirement calculation step (S140).

[0048] In the organic matter requirement calculation step (S140), the optimal organic matter requirement for removing nitrate nitrogen in the treated water (W6) is calculated. The organic matter requirement calculation step (S140) is performed by the control unit (190) calculating the optimal organic matter requirement for removing nitrate nitrogen in the treated water according to the estimated value of the nitrate nitrogen concentration in the treated water estimated through the nitrate nitrogen concentration estimation step (S130). The optimal organic matter requirement calculated in the organic matter requirement calculation step (S140) is used in the influent water distribution amount calculation step (S150).

[0049] In the influent distribution amount calculation step (S150), the amount to be injected from the water to be treated (W1) into the anoxic tank (120) is calculated. The influent distribution amount calculation step (S150) is performed by the control unit (190) calculating the amount of water to be treated according to the optimal organic matter requirement calculated in the organic matter requirement calculation step (S140). The influent injection step (S160) is performed according to the amount of water to be treated calculated in the influent distribution amount calculation step (S150).

[0050] In the influent water injection step (S160), the water to be treated (W1) is injected into the anoxic tank (120). The influent water injection step (S160) is performed by the control unit (190) controlling the operation of the water to be treated split injection unit (150) so that the water to be treated (W1) is injected into the anoxic tank (120) according to the amount of water to be treated calculated in the influent water distribution amount calculation step (S150). In the influent water injection step (S160), the injection pump (151) is operated and the anoxic injection control valve (152) is opened so that the water to be treated (W1) is injected into the anoxic tank (120) according to the amount of water to be treated calculated in the influent water distribution amount calculation step (S150).

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[0053] delete

[0054] The embodiments of FIGS. 1 and 2 are advantageous in terms of maintenance because they determine whether to recirculate internally by estimating the nitrate nitrogen level of the treated water using an EC sensor without using a nitrate nitrogen sensor.

[0055] FIG. 3 is a block diagram schematically illustrating the overall configuration of a water treatment system according to another embodiment of the present invention. Referring to FIG. 3, a water treatment system (300) according to another embodiment of the present invention comprises: a screen device (105) for removing foreign substances such as impurities from raw water (W0) to be treated; a pretreatment device (110) for removing fibers such as hair from water to be treated (W01) discharged from the screen device (105); a flow rate adjustment tank (115) for storing water to be treated (W02) discharged from the pretreatment device (110) and discharging it by adjusting the flow rate; an anoxic tank (120) for performing denitrification on water to be treated (W1) discharged from the flow rate adjustment tank (115); an anaerobic tank (125) for releasing phosphorus from an anaerobic tank effluent (W2) discharged from the anoxic tank (120); an aerobic tank (130) for performing nitrification and excessive phosphorus uptake on anaerobic tank effluent (W3) discharged from the anaerobic tank (125); and to the aerobic tank (130). An aerobic tank blower (132) that supplies air, an intermittent aeration tank (135) that is selectively operated under one of aerobic and anaerobic conditions for the aerobic tank effluent (W4) discharged from the aerobic tank (130), an intermittent aeration tank blower (137) that supplies air to the intermittent aeration tank (135), a membrane tank (140) that produces treated water (W6) by performing membrane filtration on the intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135), a membrane tank blower (143) that supplies air to the membrane tank (140), a degassing tank (145) that lowers the dissolved oxygen concentration of the membrane tank effluent (W7) discharged from the membrane tank (140) and removes nitrogen and phosphorus, an external carbon source tank (148) that injects organic matter insufficient for removing nitrogen and phosphorus into the degassing tank (145), and A treatment target water split injection unit (150) that splits and injects the treatment target water (W1) discharged from the flow rate adjustment tank (115) into an anoxic tank (120), an anaerobic tank (125), and a degassing tank (145), andAn internal return unit (155) that returns degassing tank effluent (W8) discharged from a degassing tank (145) to an intermittent aeration tank (135) and a membrane tank (140), a sludge return unit (155a) that returns degassing tank effluent (W8) discharged from a degassing tank (145) to an anoxic tank (120), an influent water EC sensor (171) that measures the electrical conductivity (EC) of the influent water to be treated (W1), an anoxic tank pH sensor (172) that measures the pH of the anoxic tank (120), an anoxic tank ORP sensor (173) that measures the oxidation-reduction potential (ORP) of the anoxic tank (120), a chemical supply unit (165) that supplies chemicals to an aerobic tank (130), and a device that measures the pH in the anaerobic tank (125). An anaerobic tank pH sensor (174), an anaerobic tank ORP sensor (175) for measuring the ORP of the anaerobic tank (125), a DO sensor (176) for measuring the dissolved oxygen (DO) of the intermittent aeration tank (135), an intermittent tank pH sensor (177) for measuring the pH of the intermittent aeration tank (135), an intermittent aeration tank ORP sensor (178) for measuring the ORP of the intermittent aeration tank (135), a treated water EC sensor (179) for measuring the electrical conductivity (EC) of the treated water (W6), a treated water pH sensor (180) for measuring the pH of the treated water (W6), a treated water ORP sensor (181) for measuring the ORP of the treated water (W6), and ammoniacal nitrogen (NH4, + An ammonia nitrogen sensor (182) for measuring the amount of -N), and nitrate nitrogen (NO3) of the treated water (W6). - A nitrate nitrogen sensor (183) for measuring the amount of -N) and phosphate phosphorus (PO4) of the treated water (W6). 3-It includes a phosphate sensor (184) for measuring the amount of -P), a degassing tank pH sensor (185) for measuring the pH in the degassing tank (145), a degassing tank ORP sensor (186) for measuring the ORP of the degassing tank (145), and a control unit (190) for controlling the operation of the intermittent aeration tank blower (137), controlling the operation of the treatment target water split injection unit (150) and the external carbon source tank (148) to control the supply of organic matter to the degassing tank (145), controlling the operation of the internal return unit (155) to control the internal return from the degassing tank (145) to the intermittent aeration tank (135), and controlling the operation of the treatment target water split injection unit (150) to control the split injection amount of the treatment target water (W1) to the anoxic tank (120).

[0056] The screen device (105) removes foreign substances, such as impurities, from the raw water (W0) to be treated. Since the screen device (105) includes the configuration of a screen device commonly used in the field of water treatment technology, a detailed description thereof is omitted here. The water to be treated (W01) discharged from the screen device (105) flows into the pretreatment device (110).

[0057] The pretreatment device (110) removes hair-like fibers from the water to be treated (W01) discharged from the screen device (105). The water to be treated (W02) discharged from the pretreatment device (110) flows into the flow rate adjustment tank (115).

[0058] The flow rate adjustment tank (115) stores the water to be treated (W02) discharged from the pretreatment device (110) and discharges it at a suitable flow rate corresponding to the treatment capacity of the water treatment system (100). The water to be treated (W1) discharged from the flow rate adjustment tank (115) is divided and injected into the anoxic tank (120), the anaerobic tank (125), and the degassing tank (145) by the water to be treated split injection unit (150). Although not illustrated, the water treatment system (100) additionally includes an influent C / N ratio measuring unit that measures the C / N ratio (ratio of organic matter to nitrogen) of the water to be treated (W1), and the measured influent C / N ratio is transmitted to the control unit (190) and used to control the supply of organic matter to the degassing tank (145).

[0059] In the anoxic tank (120), denitrification is performed on the water to be treated (W1) discharged from the flow rate adjustment tank (115). In the anoxic tank (120), the water to be treated (W1), which is discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150), and the return water (W8), which is returned from the degassing tank (145) by the internal return unit (155), are introduced. The amount of water to be treated (W1) divided and injected into the anoxic tank (120) is controlled by the control unit (190) of the water to be treated split injection unit (150) so that only the optimal amount required for denitrification is injected. In the anoxic tank (120), denitrification microorganisms release nitrogen gas using the organic matter contained in the water to be treated (W1) and the return water (W8) under anoxic conditions. The denitrifying microorganisms of the anaerobic tank (120) convert nitrate nitrogen and nitrite nitrogen into nitrogen gas by consuming oxygen contained in nitrate nitrogen or nitrite nitrogen as an electron acceptor, and consume organic matter as an electron donor for denitrification. The anaerobic tank effluent (W2) discharged from the anaerobic tank (120) flows into the anaerobic tank (125).

[0060] In the anaerobic tank (125), phosphorus release occurs from the anaerobic tank effluent (W2) discharged from the anoxic tank (120). The anaerobic tank (125) receives the anaerobic tank effluent (W2) discharged from the anoxic tank (120) and the water to be treated (W1) discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150). In the anaerobic tank (125), phosphorus-accumulating microorganisms consume organic matter contained in the anoxic tank effluent (W2) under anaerobic conditions to form storage substances such as PHB (Polyhydroxybutyrates) or PHA (Polyhydroxyalkanates). The phosphorus-accumulating microorganisms release phosphorus contained in ATP (Adenosine Triphosphate) or polyphosphate to obtain the energy required for the formation of the storage substances. The anaerobic tank effluent (W3) discharged from the anaerobic tank (125) flows into the aerobic tank (130). The pH of the anaerobic tank (125) is measured in real time by the anaerobic tank pH sensor (174). Since only the optimal amount of water to be treated (W1) is injected into the anoxic tank (120) for denitrification, the organic matter in the water to be treated (W1) in the anaerobic tank (125) can be utilized to the maximum extent, and accordingly, the phosphorus release efficiency is maximized, thereby improving the phosphorus removal performance.

[0061] In the aerobic tank (130), nitrification and excessive phosphorus intake of the anaerobic tank effluent (W3) discharged from the anaerobic tank (125) take place. The anaerobic tank effluent (W3) discharged from the anaerobic tank (125) flows into the aerobic tank (130). In the aerobic tank (130), phosphorus-accumulating microorganisms oxidize phosphorus within their bodies under aerobic conditions and excessively consume the phosphorus contained in the anaerobic tank effluent (W3), and nitrifying microorganisms oxidize the nitrogen contained in the anaerobic tank effluent (W3) and convert it into nitrate nitrogen. The aerobic tank (130) receives oxygen from the aerobic tank blower (132). Although not illustrated, the aerobic tank (130) is equipped with an air diffuser. The aerobic tank effluent (W4) discharged from the aerobic tank (130) flows into the intermittent aeration tank (135). In the aeration tank (130), a chemical is supplied by the supply unit (165) for the treatment of phosphorus (P).

[0062] The aeration tank blower (132) supplies air to the diffuser provided in the aeration tank (130) through the aeration tank air supply line (133). The operation of the aeration tank blower (132) is controlled by the control unit (190).

[0063] The intermittent aeration tank (135) is selectively operated under one of two conditions: aerobic conditions and anaerobic conditions, for the aerobic tank discharge water (W4) discharged from the aerobic tank (130). The aerobic tank discharge water (W4) discharged from the aerobic tank (130) and the return water (W8) returned from the degassing tank (145) by the internal return unit (155) are introduced into the intermittent aeration tank (135). Although not illustrated, the intermittent aeration tank (135) is equipped with an air diffuser. When air is supplied through the air diffuser (not illustrated) provided in the intermittent aeration tank (135), the intermittent aeration tank (135) functions as an aerobic tank, and when air is not supplied through the air diffuser (not illustrated) provided in the intermittent aeration tank (135), the intermittent aeration tank (135) functions as an anaerobic tank. The function of the intermittent aeration tank (135) depends on the operating state of the intermittent aeration tank blower (137). The intermittent aeration tank discharge water (W5) discharged from the intermittent aeration tank (135) flows into the membrane tank (140).

[0064] The intermittent aeration tank blower (137) supplies air to the diffuser provided in the intermittent aeration tank (135) through the intermittent aeration tank air supply line (138). The operation of the intermittent aeration tank blower (137) is controlled by the control unit (190).

[0065] The membrane tank (140) produces treated water (W6) by performing membrane filtration on the intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135). The intermittent aeration tank effluent (W5) discharged from the intermittent aeration tank (135) and the return water (W8) returned from the degassing tank (145) by the internal return unit (155) are introduced into the membrane tank (140). The membrane tank (140) receives air from the membrane tank blower (143). The membrane tank (140) is equipped with a membrane filtration device (142) that filters and treats the intermittent aeration tank effluent (W5). The membrane filtration device (142) discharges the treated water (W6) as effluent. The pH of the treated water (W6) is measured in real time by the treated water pH sensor (180), and the ammoniacal nitrogen (NH4) of the treated water (W6) +-N) is measured in real time by an ammonia nitrogen sensor (182), and the nitrate nitrogen (NO3) of the treated water (W6) is measured. - -N) is measured in real time by the nitrate nitrogen sensor (183). Since the membrane filtration device (142) includes a commonly used configuration, a detailed description thereof is omitted here. The membrane tank discharge water (W7) discharged from the membrane tank (140) flows into the degassing tank (190).

[0066] The membrane blower (143) supplies air to the membrane (140). The operation of the membrane blower (143) is controlled by the control unit (190).

[0067] The degassing tank (145) lowers the dissolved oxygen concentration of the membrane tank effluent (W7) discharged from the membrane tank (140). Accordingly, the DO concentration of the return water (W8) discharged from the degassing tank (145) and flowing into the anoxic tank (120) is lowered, thereby improving the denitrification effect in the anoxic tank (120) and the phosphorus release effect in the anaerobic tank (150). The membrane tank effluent (W7) discharged from the membrane tank (140) and the water to be treated (W1) discharged from the flow rate adjustment tank (115) and divided and injected by the water to be treated split injection unit (150) are introduced into the degassing tank (145). The degassing tank effluent (W8) discharged from the degassing tank (145) is returned to the intermittent aeration tank (135) and the membrane tank (140) by the internal return unit (155), and returned to the anoxic tank (120) by the sludge return unit (155a). The degassing tank (145) receives organic matter from the external carbon source tank (148). The degassing performance of the degassing tank (145) is improved by the organic matter contained in the water to be treated (W1) which is divided and injected into the degassing tank (145) by the water to be treated divided injection unit (150) and the organic matter supplied to the degassing tank (145) from the external carbon source tank (148).

[0068] The external carbon source (148) injects organic matter, which is insufficient for the removal of nitrogen and phosphorus, into the degassing tank (145). The operation of the external carbon source (148) is controlled by the control unit (190).

[0069] The treatment target water split injection unit (150) splits and injects the treatment target water (W1) discharged from the flow rate adjustment tank (115) into an anoxic tank (120), an anaerobic tank (125), and a degassing tank (145). The treatment target water split injection unit (150) is equipped with an injection pump (151) that transports the treatment target water (W1) discharged from the flow rate adjustment tank (115), an anoxic tank injection control valve (152) that controls the injection of the treatment target water (W1) into the anoxic tank (120), an anaerobic tank injection control valve (153) that controls the injection of the treatment target water (W1) into the anaerobic tank (125), and a degassing tank injection control valve (154) that controls the injection of the treatment target water (W1) into the degassing tank (120).

[0070] The injection pump (151) transfers the water to be treated (W1) discharged from the flow rate adjustment tank (115) through the main injection line (150a).

[0071] An anaerobic tank injection control valve (152) is installed in an anaerobic tank injection line (150b) that branches off from the main injection line (150a) and communicates with the anaerobic tank (120), thereby controlling the injection of the water to be treated (W1) into the anaerobic tank (120). The ON / OFF operation of the anaerobic tank injection control valve (152) is controlled by the control unit (190).

[0072] The anaerobic tank injection control valve (153) is installed in the anaerobic tank injection line (150c), which branches off from the main injection line (150a) and communicates with the anaerobic tank (125), to control the injection of the water to be treated (W1) into the anaerobic tank (125). The ON / OFF operation of the anaerobic tank injection control valve (153) is controlled by the control unit (190).

[0073] The degassing tank injection control valve (154) is installed in the degassing tank injection line (150d), which branches off from the main injection line (150a) and communicates with the degassing tank (145), thereby controlling the injection of the water to be treated (W1) into the degassing tank (145). The ON / OFF operation of the degassing tank injection control valve (154) is controlled by the control unit (190).

[0074] The internal return unit (155) returns the degassed tank discharge water (W8) discharged from the degassed tank (145) to the intermittent aeration tank (135) and the membrane tank (140), respectively. The internal return unit (155) is equipped with an internal return pump (156) for transporting the degassed tank discharge water (W8) discharged from the degassed tank (145), an intermittent aeration tank return control valve (158) for controlling the return of the degassed tank discharge water (W8) to the intermittent aeration tank (135), and a membrane tank return control valve (159) for controlling the return of the degassed tank discharge water (W8) to the membrane tank (140).

[0075] The internal return pump (156) transfers the degassing tank wastewater (W8) discharged from the degassing tank (145) to the intermittent aeration tank (135) and the membrane tank (140) through the internal return line (157).

[0076] The intermittent aeration tank return control valve (158) is installed in the internal return line (157) to control the injection of degassing tank discharge water (W8) into the intermittent aeration tank (135). The ON / OFF operation of the intermittent aeration tank return control valve (158) is controlled by the control unit (190).

[0077] The membrane tank return control valve (159) is installed in the internal return line (157) to control the return of the degassing tank discharge water (W8) to the membrane tank (140). The ON / OFF operation of the membrane tank return control valve (159) is controlled by the control unit (190).

[0078] The sludge return unit (155a) returns the degassing tank effluent (W8) discharged from the degassing tank (145) to the anoxic tank (120). The sludge return unit (155a) is equipped with a sludge return pump (156a) that transports the degassing tank effluent (W8) discharged from the degassing tank (145), and an anoxic tank return control valve (158a) that controls the return of the degassing tank effluent (W8) to the anoxic tank (120).

[0079] The sludge return pump (156a) transfers the degassing tank effluent (W8) discharged from the degassing tank (145) to the anoxic tank (120) through the sludge return line (155b).

[0080] The anoxic tank return control valve (158a) is installed in the sludge return line (155b) to control the return of the degassing tank effluent (W8) to the anoxic tank (120). The ON / OFF operation of the anoxic tank return control valve (158a) is controlled by the control unit (190).

[0081] The chemical supply unit (165) supplies a chemical for treating phosphorus (P) to the aerobic tank (130). The chemical supply unit (165) is equipped with a chemical storage tank (166) in which a coagulant, which is a chemical for treating phosphorus (P), is stored, and a line mixer (167) that mixes the chemical with the return water (W8) flowing into the aerobic tank (130). The chemical supply unit (165) supplies the chemical according to the total phosphorus (TP) concentration of the treated water (W6). The operation of the chemical supply unit (165) is controlled by the control unit (190).

[0082] The chemical storage tank (166) stores a coagulant, which is a chemical for treating phosphorus (P). The coagulant stored in the chemical storage tank (166) is supplied to the line mixer (167).

[0083] The line mixer (167) mixes the coagulant supplied from the chemical storage tank (166) with the return water (W8) flowing into the aerobic tank (130).

[0084] The influent water EC sensor (171) measures the electrical conductivity (EC) of the influent water (W1) to be treated. The EC of the influent water measured by the influent water EC sensor (171) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the influent water EC sensor (171) is not an essential sensor in the water treatment system (300), it may be omitted, and this is also within the scope of the present invention.

[0085] The anaerobic tank pH sensor (172) measures the pH of the anaerobic tank (120). The pH value of the anaerobic tank (120) measured by the anaerobic tank pH sensor (172) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the anaerobic tank pH sensor (172) is not an essential sensor in the water treatment system (300), it may be omitted, and this is also within the scope of the present invention.

[0086] The anaerobic tank ORP sensor (173) measures the oxidation-reduction potential (ORP) of the anaerobic tank (120). The ORP measurement value of the anaerobic tank (120) measured by the anaerobic tank ORP sensor (173) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the anaerobic tank ORP sensor (173) is not an essential sensor in the water treatment system (300), it may be omitted, and this is also within the scope of the present invention.

[0087] The anaerobic tank pH sensor (174) measures the pH in the anaerobic tank (125) in real time. The pH value of the anaerobic tank (125) measured by the anaerobic tank pH sensor (174) is transmitted to the control unit (190) and used for aeration control of the intermittent aeration tank (135).

[0088] The anaerobic tank ORP sensor (175) measures the ORP of the anaerobic tank (125). The ORP measurement value of the anaerobic tank (125) measured by the anaerobic tank ORP sensor (175) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the anaerobic tank ORP sensor (175) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0089] The DO sensor (176) measures dissolved oxygen (DO) in real time in the intermittent aeration tank (135). The DO measurement value of the intermittent aeration tank (135) measured by the DO sensor (176) is transmitted to the control unit (190) and used for aeration control of the intermittent aeration tank (135).

[0090] The intermittent tank pH sensor (177) measures the pH in the intermittent aeration tank (135). The pH value of the intermittent tank (135) measured by the intermittent tank pH sensor (177) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the intermittent tank pH sensor (177) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0091] The intermittent aeration tank ORP sensor (178) measures the ORP of the intermittent aeration tank (135). The ORP measurement value of the intermittent aeration tank (135) measured by the intermittent aeration tank ORP sensor (178) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the intermittent aeration tank ORP sensor (178) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0092] The treated water EC sensor (179) measures the electrical conductivity (EC) of the treated water (W6) in real time. The EC of the treated water (W6) measured by the treated water EC sensor (179) is transmitted to the control unit (190) and used to control the operation of the treated water split injection unit (150) and the external carbon source (148), and to control the operation of the internal return unit (155).

[0093] The treated water pH sensor (180) measures the pH of the treated water (W6) in real time. The pH value of the treated water (W6) measured by the treated water pH sensor (180) is transmitted to the control unit (190) and used for aeration control of the intermittent aeration tank (135).

[0094] The treated water ORP sensor (181) measures the ORP of the treated water (W6). The ORP measurement value of the treated water (W6) measured by the treated water ORP sensor (181) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the treated water ORP sensor (181) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0095] The ammonia nitrogen sensor (182) is ammonia nitrogen (NH4) contained in the treated water (W6). + The amount of -N) is measured in real time. The amount of ammonia nitrogen (NH4) of the treated water (W6) measured by the ammonia nitrogen sensor (182). + -N) The measured value is transmitted to the control unit (190) and used for aeration control of the intermittent aeration tank (135). The ammonia nitrogen sensor (182) is not an essential sensor in the water treatment system (300) and may be omitted, which is within the scope of the present invention.

[0096] The nitrate nitrogen sensor (183) detects nitrate nitrogen (NO3) contained in the treated water (W6). - The amount of -N) is measured in real time. The nitrate nitrogen (NO3) of the treated water (W6) measured by the nitrate nitrogen sensor (183)- -N) The measured value is transmitted to the control unit (190) and used to control the operation of the water split injection unit (150) and the internal return unit (155). The nitrate nitrogen sensor (183) is not an essential sensor in the water treatment system (300) and may be omitted, which is within the scope of the present invention.

[0097] The phosphate phosphorus sensor (184) is a phosphate phosphorus (PO4) contained in the treated water (W6). 3- Measure the amount of -P). The amount of phosphate phosphorus (PO4) of the treated water (W6) measured by the phosphate phosphorus sensor (184). 3- -P) The measured value is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the phosphate sensor (184) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0098] The degassing tank pH sensor (185) measures the pH in the degassing tank (145). The pH value of the degassing tank (145) measured by the degassing tank pH sensor (185) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the degassing tank pH sensor (185) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0099] The degassing tank ORP sensor (186) measures the ORP of the degassing tank (145). The ORP measurement value of the degassing tank (145) measured by the degassing tank ORP sensor (186) is transmitted to the control unit (190) and used for the operation control of the water treatment system (300). Since the degassing tank ORP sensor (186) is not an essential sensor in the water treatment system (300), it may be omitted and falls within the scope of the present invention.

[0100] Under the first operating condition of the water treatment system (300), the control unit (190) controls the aeration operation of the intermittent aeration tank (135) using the anaerobic tank pH value measured by the anaerobic tank pH sensor (174), the treated water pH value measured by the treated water pH sensor (180), the intermittent aeration tank DO value measured by the DO sensor (176), and the ammonia nitrogen value of the treated water (W6) measured by the ammonia nitrogen sensor (182). Under the first operating condition of the water treatment system (300), the control unit (190) uses the correlation between the degree of oxidation of ammonia nitrogen and the amount of change in the pH value to determine the ammonia nitrogen (NH4) of the treated water from the anaerobic tank pH value and the treated water pH value. + The operation of the intermittent aeration tank blower (137) is controlled by estimating the -N concentration.

[0101] In the second operating condition of the water treatment system (300), the control unit (190) controls the operation of the water split injection unit (150) and the external carbon source tank (148) to supply organic matter to the degassing tank (145). To control the operation of the water split injection unit (150) and the external carbon source tank (148), the control unit (190) uses the electrical conductivity (EC) of the treated water (W6) measured by the treated water EC sensor (179) and the nitrate nitrogen (NO3) of the treated water (W6) measured by the nitrate nitrogen sensor (183). - -N) Uses the measured value. In the second operating condition of the water treatment system (300), the control unit (190) uses the measured EC value of the treated water based on the correlation between the nitrate nitrogen and the electrical conductivity of the treated water (W6) to control the operation of the divided injection unit (150) of the treated water.

[0102] In the third operating condition of the water treatment system (300), the control unit (190) controls the operation of the internal return unit (155) to control the internal return from the degassing tank (145) to the intermittent aeration tank (135). To control the operation of the internal return unit (155), the control unit (190) uses the electrical conductivity (EC) of the treated water (W6) measured by the treated water EC sensor (179) and the nitrate nitrogen (NO3) of the treated water (W6) measured by the nitrate nitrogen sensor (183). - -N) Uses the measured value. In the third operating condition of the water treatment system (300), the control unit (190) uses the treated water EC measured value based on the correlation between the nitrate nitrogen and the electrical conductivity of the treated water (W6) to control the operation of the internal return unit (155).

[0103] In the fourth operating condition of the water treatment system (300), the control unit (190) controls the treatment target water split injection unit (150) to regulate the amount of influent water (W1) that is split and injected into the anoxic tank (120). To control the operation of the treatment target water split injection unit (150), the control unit (190) uses the electrical conductivity (EC) of the treatment water (W6) measured by the treatment water EC sensor (179) and the nitrate nitrogen (NO3) of the treatment water (W6) measured by the nitrate nitrogen sensor (183). - -N) Use the measured value. The fourth operating condition of the water treatment system (300) is as described with reference to FIG. 2 and FIG. 4.

[0104] Although the present invention has been described through the above embodiments, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will understand that such modifications and changes are also within the scope of the present invention. Explanation of the symbols

[0105] 200: Water Treatment System 105: Screen Device 110: Pretreatment Device 115: Flow Equalizer 120: Anoxic Tank 125: Anaerobic Tank 130: Aerobic Tank 135: Intermittent Aeration Tank 137: Intermittent Aeration Tank Blower 140: Membrane Tank 145: Degassing Tank 148: External Carbon Source Tank 150: Water to be Treated Split Injection Unit 151: Injection Pump 152: Anoxic Tank Injection Control Valve 155: Internal Recirculation Unit 174: Anaerobic Tank pH Sensor 176: DO Sensor 179: Treated Water EC Sensor 180: Treated Water pH Sensor 182: Ammonia Nitrogen Sensor 183: Nitrate Nitrogen Sensor 190: Control Unit 300: Water Treatment System

Claims

Claim 1 An anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on the water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on the anaerobic tank effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on the anaerobic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank selectively operated under one of aerobic and anoxic conditions for the aerobic tank effluent discharged from the aerobic tank; a membrane tank equipped with a membrane filtration device that filters and treats the intermittent aeration tank effluent discharged from the intermittent aeration tank; a treated water EC sensor for measuring the electrical conductivity of the treated water discharged from the membrane filtration device; a degassing tank that lowers the dissolved oxygen concentration of the membrane tank effluent discharged from the membrane tank and removes nitrogen and phosphorus; and a tank for dividing and injecting the water to be treated into the anoxic tank, the anaerobic tank, and the degassing tank. A water treatment system comprising: a split injection unit for water to be treated; and a control unit that controls the operation of the split injection unit for water to be treated using a measured value of the treated water EC measured by the treated water EC sensor, wherein the control unit uses the measured value of the treated water EC based on the correlation between the nitrate nitrogen and the electrical conductivity of the treated water to control the operation of the split injection unit for water to be treated. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 An anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on the water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on the anaerobic tank effluent discharged from the anoxic tank under anaerobic conditions; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on the anaerobic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank that selectively operates under one of aerobic and anoxic conditions for the aerobic tank effluent discharged from the aerobic tank; an intermittent aeration tank blower that supplies air to the intermittent aeration tank; a membrane tank equipped with a membrane filtration device that filters and treats the intermittent aeration tank effluent discharged from the intermittent aeration tank; a treated water EC sensor that measures the electrical conductivity (EC) of the treated water discharged from the membrane filtration device; and lowering the dissolved oxygen concentration of the membrane tank effluent discharged from the membrane tank and nitrogen and phosphorus A method of operating a water treatment system comprising: a degassing tank for removal; a divided injection unit for dividing and injecting the water to be treated into the anoxic tank, the anaerobic tank, and the degassing tank; and a control unit for controlling the operation of the divided injection unit for the water to be treated, wherein the control unit confirms the measured value of the treated water EC measured by the treated water EC sensor; a nitrate nitrogen concentration estimation step in which the control unit estimates the nitrate nitrogen concentration of the treated water using the measured value of the treated water EC and calculates an estimated value of the treated water nitrate nitrogen concentration; an organic matter requirement calculation step in which the control unit calculates an optimal organic matter requirement for removing nitrate nitrogen from the treated water according to the estimated value of the treated water nitrate nitrogen concentration; and an influent distribution amount calculation step in which the control unit calculates the injection amount of the water to be treated according to the optimal organic matter requirement.A method of operating a water treatment system, comprising: an influent injection step in which the control unit controls the operation of the divided injection unit for the water to be treated so that the water to be treated is injected into the anoxic tank according to the injection amount of the water to be treated; and a nitrate nitrogen concentration estimation step in which the control unit calculates the nitrate nitrogen concentration estimation value using the EC measurement value of the treated water based on the correlation between the nitrate nitrogen and electrical conductivity of the treated water. Claim 6 An anoxic tank in which nitrogen removal by denitrifying microorganisms is performed on the water to be treated under anoxic conditions; an anaerobic tank in which phosphorus release by phosphorus-accumulating microorganisms is performed on the anaerobic tank effluent discharged from the anoxic tank under anaerobic conditions; an anaerobic tank pH sensor for measuring the pH of the anaerobic tank; an aerobic tank in which phosphorus over-uptake by phosphorus-accumulating microorganisms and nitrogen oxidation by nitrifying microorganisms are performed on the anaerobic tank effluent discharged from the anaerobic tank under aerobic conditions; an intermittent aeration tank that selectively operates under one of aerobic and anoxic conditions for the aerobic tank effluent discharged from the aerobic tank; an intermittent aeration tank blower for supplying air to the intermittent aeration tank; a DO sensor for measuring dissolved oxygen in the intermittent aeration tank; a membrane tank equipped with a membrane filtration device for filtering and treating the intermittent aeration tank effluent discharged from the intermittent aeration tank; an EC sensor for measuring the electrical conductivity of the treated water discharged from the membrane filtration device; and the pH of the treated water A water treatment system comprising: a pH sensor for measuring treated water; a degassing tank for lowering the dissolved oxygen concentration of the effluent from the membrane tank and removing nitrogen and phosphorus; a divided injection unit for dividing and injecting the treated water into the anoxic tank, the anaerobic tank, and the degassing tank; an internal return unit for returning the degassing tank effluent discharged from the degassing tank to the anoxic tank, the intermittent aeration tank, and the membrane tank; and a control unit for controlling the operation of the intermittent aeration tank blower, the divided injection unit for treated water, and the internal return unit, wherein the intermittent aeration tank blower is controlled using the anaerobic tank pH value measured by the anaerobic tank pH sensor, the treated water pH value measured by the treated water pH sensor, and the intermittent aeration tank DO concentration measured by the DO sensor, and the divided injection unit for treated water and the internal return unit are controlled using the treated water EC value measured by the treated water EC sensor. Claim 7 delete Claim 8 In claim 6, an influent EC sensor for measuring the EC of the water to be treated; an anoxic tank pH sensor for measuring the pH of the anoxic tank; an anoxic tank ORP sensor for measuring the oxidation-reduction potential (ORP) of the anoxic tank; an anaerobic tank ORP sensor for measuring the ORP of the anaerobic tank; an intermittent tank pH sensor for measuring the pH of the intermittent aeration tank; an intermittent aeration tank ORP sensor for measuring the ORP of the intermittent aeration tank; a treated water ORP sensor for measuring the ORP of the treated water; and ammoniacal nitrogen (NH4) contained in the treated water + An ammonia nitrogen sensor for measuring (-N); nitrate nitrogen (NO3) contained in the treated water. - A nitrate nitrogen sensor for measuring -N; phosphate phosphorus (PO4) contained in the treated water 3- A water treatment system further comprising: a phosphate sensor for measuring -P; a degassing tank pH sensor for measuring the pH of the degassing tank; and a degassing tank ORP sensor for measuring the ORP of the degassing tank.

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