WO2017006988A1 - Wastewater treatment control unit and wastewater treatment system - Google Patents

Abstract

A wastewater treatment control unit of an embodiment has a target value acquisition unit, a predicted value acquisition unit, and an air volume control unit. On the basis of an initial value for at least one of trans membrane pressure and membrane filter resistance for a separation membrane for filtering activated sludge, the target value acquisition unit acquires a target value for at least one of the trans membrane pressure and membrane filter resistance after measurement of the initial values. The predicted value acquisition unit acquires a predicted value for at least one of the trans membrane pressure and membrane filter resistance after measurement of the initial values on the basis of measured values related to clogging of the separation membrane. The air volume control unit controls the air volume for air supplied toward the separation membrane from an air diffuser on the basis of the target value acquired by the target value acquisition unit and the predicted value acquired by the predicted value acquisition unit.

Description

Waste water treatment control device and waste water treatment system

Embodiments of the present invention relate to a wastewater treatment control device and a wastewater treatment system.

Dirty water flowing through the sewer pipe is supplied to the aeration tank through the screen, the sand basin, and the first sedimentation basin. Organic substances in sewage are decomposed into carbon dioxide and water by heterotrophic bacteria that are a kind of microorganisms contained in activated sludge in the aeration tank. In addition, the ammonia component in the sewage is decomposed into nitric acid and water by nitrifying bacteria (nitrite bacteria and nitrate bacteria) which are a kind of microorganisms contained in the activated sludge in the aeration tank. Through these degradation reactions, heterotrophic bacteria and nitrifying bacteria each grow.

The treated water after organic substances and ammonia in the sewage are decomposed and removed is separated from the activated sludge by a separation membrane placed in the aeration tank. Solid components in the activated sludge cannot pass through the separation membrane, and only treated water passes through the separation membrane. The treated water that has passed through the separation membrane is discharged from the aeration tank.

As the treated water is discharged by the separation membrane, microorganisms contained in the activated sludge, macromolecular compounds such as EPS (Extracellular-Polymeric Substance) that are metabolites of microorganisms, inorganic substances, etc., enter the treated-water passage of the separation membrane. Get in. Thereby, clogging of the separation membrane occurs gradually. In order to detect this clogging state, the membrane pressure difference (TMP: Trans Membrane Pressure) is the difference between the upstream (primary) water pressure and the downstream (secondary) water pressure of the separation membrane when the treated water is discharged. Is measured.

¡When clogging of the separation membrane occurs, the membrane differential pressure required to obtain the same treated water discharge flow rate gradually increases. In order to suppress clogging of the separation membrane, an aeration unit for air-cleaning the separation membrane is provided in the aeration tank below the separation membrane. In the technique of Patent Document 1, the amount of air supplied from the air diffuser is adjusted by PID (Proportional-Integral-Derivative) control based on the difference value between the target value of the membrane differential pressure and the actual measurement value. Note that the target value of the membrane differential pressure is set to a value that increases linearly with the passage of time.

However, the membrane differential pressure has a small change at the initial stage of use of the separation membrane, and tends to increase rapidly when the membrane differential pressure exceeds a predetermined value (for example, 10 [kPa]). For this reason, if the target value of the membrane differential pressure is set to a value that increases linearly with the passage of time, the actual membrane differential pressure may deviate greatly from the target value. If the difference between the actual membrane pressure difference and the target value is large, there is a possibility that the amount of air supplied to the separation membrane cannot be calculated appropriately.

JP 2013-202471 A

The problem to be solved by the present invention is to provide a wastewater treatment control device and a wastewater treatment system capable of reducing the difference between the actual membrane differential pressure of the separation membrane and the target value of the membrane differential pressure.

The wastewater treatment control apparatus of the embodiment has a target value acquisition unit, a predicted value acquisition unit, and an air volume control unit. The target value acquisition unit is based on at least one of the initial value of the membrane differential pressure and membrane filtration resistance of the separation membrane that filters activated sludge, and the target value of the membrane differential pressure and membrane filtration resistance after the measurement of the initial value Get at least one of The predicted value acquisition unit acquires at least one of the predicted value of the membrane differential pressure and the membrane filtration resistance after the measurement value is measured based on the measured value related to the clogging of the separation membrane. The air volume control unit is configured to control the amount of air supplied from the aeration unit toward the separation membrane based on the target value acquired by the target value acquisition unit and the predicted value acquired by the predicted value acquisition unit. Control airflow.

The figure which shows the sewage treatment system 10 of 1st Embodiment. The figure which shows the process implemented in the aeration tank 400 of 1st Embodiment. 1 is a block diagram of a sewage treatment system 10 according to a first embodiment. The figure which shows the relationship between the film differential pressure | voltage and time in 1st Embodiment. The flowchart which shows the process of the target value acquisition part 451 in 1st Embodiment. The flowchart which shows the process of the predicted value acquisition part 453 in 1st Embodiment. The flowchart which shows the process of the air volume control part 452 in 1st Embodiment. The block diagram of the sewage treatment system 10 of 4th Embodiment. The figure which shows the process implemented in the aeration tank 400 of 5th Embodiment. The block diagram of the sewage treatment system 10 of 6th Embodiment. The figure for demonstrating operation | movement of the blower control part 417 in 6th Embodiment. The figure which shows the specific example of a control mode determination table. The flowchart which shows the process of the air volume control part 452 in 8th Embodiment.

Hereinafter, the wastewater treatment control device and the wastewater treatment system of the embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a sewage treatment system 10 as a wastewater treatment system according to the first embodiment. The sewage treatment system 10 includes a screen 100, a sand basin 200, an initial sedimentation basin 300, an aeration tank 400, and a treatment water tank 500.

The screen 100 removes large garbage (hair, toilet paper, etc.), pebbles, etc. from the sewage flowing into the sewage treatment system 10. Sewage discharged through the screen 100 flows into the sand basin 200.

The earth and sand that could not be removed by the screen 100 and the floating matter having a specific gravity larger than that of water are submerged in the bottom of the sand basin 200. Sediment or the like that sinks to the bottom of the sand basin 200 is removed by a dust remover. The sewage discharged from the sand basin 200 without being removed by the dust remover first flows into the sedimentation basin 300.

Sediment that could not be removed by the sedimentation basin 200, such as sludge, having a specific gravity greater than that of water, is first submerged in the bottom of the sedimentation basin 300. The sludge or the like that first sinks to the bottom of the sedimentation basin 300 is collected and removed by a scraper. The sewage discharged from the sedimentation basin 300 without being removed by the scraper first flows into the aeration tank 400.

Air is blown into the activated sludge in the aeration tank 400. As a result, organic matter and ammonia in the sewage are decomposed and removed. The treated water in the activated sludge is discharged using a separation membrane. Details of the biochemical treatment performed in the aeration tank 400 will be described later with reference to FIG.

The sewage discharged through the separation membrane flows into the treated water tank 500.

In the treated water tank 500, a disinfectant such as sodium hypochlorite is introduced as necessary. Thereby, pathogenic bacteria such as Escherichia coli are sterilized. The treated water sterilized in the treated water tank 500 is discharged into a river or the sea. The above is the overall processing flow of the sewage treatment system 10.

FIG. 2 is a diagram illustrating a process performed in the aeration tank 400 according to the first embodiment. The sewage discharged from the sedimentation basin 300 first flows into the aeration tank 400 through the flow path 401. In the aeration tank 400, activated sludge in which aerobic microorganisms (heterotrophic bacteria, nitrifying bacteria, etc.) are activated is stored.

The blower 402 supplies air into the pipe 403. The aeration unit 404 is an aeration apparatus that supplies the air that has passed through the pipe 403 to the activated sludge in the aeration tank 400. Thereby, the bubbles 405 are released into the activated sludge in the aeration tank 400. The flow meter 406 measures the air volume of air supplied from the blower 402.

Organic substances in the sewage are decomposed by heterotrophic bacteria in the aeration tank 400. Specifically, when the organic substance is glucose, as shown in the following chemical formula (1), the organic substance (C ₆ H ₁₂ O ₆ ) is oxygen (O) contained in the air supplied from the aeration unit 404. ₂ ) and is decomposed into carbon dioxide (CO ₂ ) and water (H ₂ O).

The ammonia component in the sewage is decomposed by nitrifying bacteria (nitrite bacteria and nitrate bacteria) in the aeration tank 400. Specifically, as shown in the following chemical formula (2), ammonium ions (NH ₄ ⁺ ) react with oxygen (O ₂ ) contained in the air supplied from the aeration unit 404 to form nitrate ions (NO ₃ ^- ), Hydrogen ions (H ⁺ ), and water (H ₂ O).

The separation membrane 407 is soaked in the sewage in the aeration tank 400. The separation membrane 407 is a porous flat membrane provided with a plurality of permeation channels having an average pore diameter of 0.4 [μm], for example. The size of the microorganisms contained in the activated sludge is about 1 [μm] (bacteria) to several tens [μm] (protozoa, etc.). For this reason, microorganisms contained in the activated sludge cannot pass through the separation membrane 407, and only clear treated water passes through the separation membrane 407. The treated water that has passed through the separation membrane 407 flows through the pipe 409 when the suction pump 408 is driven.

The pipe 409 is provided with a pressure gauge 410 and a flow meter 411. Based on the measured value of the pressure gauge 410, the membrane differential pressure of the separation membrane 407 can be calculated. The flow meter 411 measures the flow rate of treated water flowing through the pipe 409.

The blower 412 supplies air into the pipe 413. The air diffuser 414 is an air diffuser that supplies air from the pipe 413 toward the separation membrane 407. Thereby, the bubbles 415 are released into the activated sludge in the aeration tank 400. The air diffuser 414 discharges the bubbles 415 toward the separation membrane 407, whereby the surface of the separation membrane 407 is cleaned. Thereby, clogging of the separation membrane 407 is suppressed. The flow meter 416 measures the air volume of air supplied from the blower 412.

In addition, when the membrane differential pressure of the separation membrane 407 reaches a preset upper limit value, the separation membrane 407 is cleaned with a chemical solution. Specifically, the inflow sewage into the aeration tank 400 is temporarily stopped. Thereafter, the separation membrane 407 is cleaned by injecting a chemical solution such as sodium hypochlorite or oxalic acid from the downstream side (secondary side) of the separation membrane 407. When the cleaning of the separation membrane 407 is completed, the membrane differential pressure of the separation membrane 407 is restored to near the initial value. The separation membrane 407 cleaned with the chemical solution is used again in the aeration tank 400.

FIG. 3 is a block diagram of the sewage treatment system 10 of the first embodiment. The sewage treatment system 10 includes a control device 450. The control device 450 includes a processor such as a CPU (Central Processing 等 Unit) and a memory that stores a program executed by the processor.

The control device 450 implements the functions of the target value acquisition unit 451, the air volume control unit 452, and the predicted value acquisition unit 453 by executing a program stored in the memory. Note that the target value acquisition unit 451, the air volume control unit 452, and the predicted value acquisition unit 453 may be hardware such as LSI (Large Scale Integration) or ASIC (Application Specific Specific Integrated Circuit).

First, the processing of the target value acquisition unit 451 will be described. The target value acquisition unit 451 calculates the target value TMPref (t) of the membrane differential pressure TMP (t) of the separation membrane 407 as a function of t by solving the differential equation of the following formula (3). Note that t represents time.

Here, the blockage index k is a parameter representing the degree of blockage of the separation membrane 407. The occlusion index k is a positive value. When k = 1, the solution of Equation (3) is a function that increases the film differential pressure TMP (t) exponentially. On the other hand, when k> 1, the value of the film differential pressure TMP (t) becomes a function that diverges infinitely in a certain finite time.

The occlusion index k is set to any value of k = 1, 1.5, and 2 by judging the degree of progression of occlusion of the separation membrane 407. For example, k = 1 is set for intermediate blockage, k = 1.5 for standard blockage, and k = 2 for complete blockage.

When k = 1 is set, the target value acquisition unit 451 calculates the parameter A in Expression (3) based on Expression (4) below. Here, TMP ₀ is an initial value of the membrane differential pressure TMP (t), L is a maintenance cycle, and TMPlim is an upper limit value of the membrane differential pressure TMP (t). The initial value TMP ₀ is measured by the pressure gauge 410. Further, the operator uses the input unit 460 such as a mouse or a keyboard to input the closing index k, the maintenance cycle L, and the upper limit value TMPlim.

When set with k> 1, the target value acquisition unit 451 calculates the parameter A in Expression (3) based on Expression (5) below.

FIG. 4 is a diagram showing the relationship between the film differential pressure and time in the first embodiment. As shown in FIG. 4, the initial value TMP ₀ is the membrane differential pressure at the timing (T ₀ ) immediately after the separation membrane 407 is washed with the chemical solution. The maintenance cycle L is a cycle in which the separation membrane 407 is maintained (chemical solution cleaning). Specifically, the maintenance cycle L is the time from the timing (T ₀ ) immediately after the chemical cleaning of the separation membrane 407 to the next chemical cleaning timing (Tlim). The maintenance cycle L is set to 30 days, for example. The upper limit value TMPlim is set to 20 [kPa], for example.

The pressure gauge 410 measures the initial value TMP ₀ of the membrane differential pressure at the timing (T ₀ ) when the filtration operation after the separation membrane 407 is washed with the chemical solution is resumed. The pressure gauge 410 transmits the measured initial value TMP ₀ to the target value acquisition unit 451 of the control device 450. On the other hand, the operator inputs the closing index k, the maintenance cycle L, and the upper limit value TMPlim using the input unit 460 such as a mouse or a keyboard. The input unit 460 transmits the input blocking index k, the maintenance cycle L, and the upper limit value TMPlim to the target value acquisition unit 451 of the control device 450.

The target value acquisition unit 451 calculates the parameter A using Equation (4) or Equation (5) based on the received initial value TMP ₀ , blockage index k, maintenance cycle L, and upper limit value TMPlim. The target value acquisition unit 451 calculates the target value TMPref (t) of the membrane differential pressure TMP (t) of the separation membrane 407 by solving the differential equation of Formula (3) using the calculated parameter A and the blockage index k. calculate.

The target value acquisition unit 451 uses the parameter A and the blocking index k based on Lp smaller than the maintenance cycle L and membrane pressure TMPmax smaller than the upper limit value TMPlim instead of the maintenance cycle L and the upper limit value TMPlim. May be calculated simultaneously.

For example, when the membrane differential pressure TMP (t) reaches 10 [kPa], it may be difficult to suppress an increase in the membrane differential pressure TMP (t) even if the air volume of the blower 412 is increased. In this case, the target value acquisition unit 451 may calculate TMPmax (10 [kPa]) instead of the upper limit value TMPlim (20 [kPa]). Further, the target value acquisition unit 451 may set a time Lp (20 days) until the membrane differential pressure TMP (t) reaches 10 [kPa] instead of the maintenance cycle L (30 days). As a result, the optimum parameter A and the blockage index k can be calculated simultaneously using the equations (3) to (5). On the other hand, in this method, it is difficult to obtain analytical solutions such as Equations (4) and (5), and therefore parameter A and blockage index k are calculated by numerical search.

Specifically, for example, the value of k can be searched for by the following procedure.
(STEP1)
Assuming that k = 1, the target value acquisition unit 451 sets A (= A1) in Equation (4) for the combination of (L and TMPlim) and A (=) in Equation (4) for the combination of (Lp and TMPmax). A2) is calculated, and it is checked whether A1 = A2. When A1 = A2, k = 1. If A1 ≠ A2, proceed to STEP2.

(STEP2)
The target value acquisition unit 451 solves the simultaneous equations of Equation (5) for the combination of (L and TMPlim) and the combination of (Lp and TMPmax). As a search method, an appropriate search algorithm such as a Newton method can be used. As another method, for example, the target value acquisition unit 451 gradually increases k from k = 1 + α (a small amount of α> 0) to calculate A1 and A2 for Equation (5), respectively, and | A1 A method such as finding k that satisfies −A2 | <ε (ε: allowable error) is adopted.

As another k setting method, when a prediction model of formulas (9) and (10) to be described later is constructed, k that most closely matches the past actual data is obtained by searching, and the value is calculated by formula. It can also be adopted as k of the target curve of the target value acquisition unit 451 of (3) to (5).

Next, processing of the predicted value acquisition unit 453 will be described. The predicted value acquisition unit 453 calculates the predicted value TMPhat (t) of the membrane differential pressure TMP (t) of the separation membrane 407 as a function of t by solving the following mathematical formula (6).

Here, the flux J (t) is the amount of treated water that passes through the separation membrane 407 per unit area per unit time at time t. Specifically, the predicted value acquisition unit 453 calculates the flux J (t) by dividing the flow rate Q ₁ (t) measured by the flow meter 411 by the membrane area Ma of the separation membrane 407.

The above equation (6) is obtained by eliminating R (t) from the following equations (7) and (8) and defining the coefficient of TMP (t) ^k as Am (t). Where μ is the viscosity coefficient, J (t) is the flux, R (t) is the membrane filtration resistance, k is the blockage index (k = 1, 1.5, 2), and f (X) is the membrane filtration resistance. It is a factor to make. Usually, f (X) is proportional to the flux J (t) or proportional to the water quality concentration c × flux J (t).

On the other hand, when the value of the flux J (t) is controlled to be constant, the above formula (6) is expressed by the following formula (9). Expression (9) is an expression in which the parameter A in Expression (3) is replaced with the parameter Am (t).

The parameters Am (t) included in the prediction models of Equation (6) and Equation (9) are, as shown in Equation (10), coefficient a ₁ , coefficient a ₂ , flux X ₁ (t), and air volume X. ₂ Calculated based on (t). Here, the predicted value acquisition unit 453 uses the aforementioned flux J (t) as the flux X ₁ (t). Further, the predicted value acquisition unit 453 uses the air volume Q ₂ (t) received from the flow meter 416 as the air volume X ₂ (t).

In Formula (10), X ₂ (t) is the air volume supplied from the blower 412, but X ₂ (t) may be the air magnification of the air supplied from the blower 412. The air magnification means the ratio of the amount of air sent to the aeration tank 400 to the amount of sewage flowing into the aeration tank 400.

The predicted value acquisition unit 453 calculates the parameter Am (t) using Equation (10) based on the flux X ₁ (t) (= J (t)) and the air volume X ₂ (t) (= Q ₂ (t)). Is calculated. The predicted value acquisition unit 453 solves the differential equation of Equation (6) using the calculated parameter Am (t), the flux J (t), and the blockage index k, whereby the membrane pressure difference TMP ( The predicted value TMPhat (t) of t) is calculated.

Next, processing of the air volume control unit 452 will be described. The air volume control unit 452 controls the air volume of the blower 412 based on the target value TMPref (t) calculated by the target value acquisition unit 451 and the predicted value TMPhat (t) calculated by the predicted value acquisition unit 453. . This point will be described in detail below.

The air volume control unit 452 calculates a difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t) based on Expression (11).

Next, the air volume control unit 452 performs PI (Proportional-Integral) control on the blower 412 using the calculated difference E (t). Specifically, the air volume control unit 452 calculates the operation amount u (t) of the blower 412 based on Expression (12). Kp is a proportional gain in PI control. Ki is an integral gain in PI control. Tnow is the current time. Tp is the elapsed time from the current time Tnow. For example, Tp is set to 1 day (24 hours).

As shown in FIG. 4, the target value TMPref (t) of the membrane differential pressure is indicated by a thick solid line. The actually measured value TPMact (t) of the membrane differential pressure is indicated by a thin solid line. The predicted value TMPhat (t) of the film differential pressure after the current time Tnow is indicated by a broken line.

At the current time Tnow, the target value of the membrane differential pressure and the actual measured value of the membrane differential pressure are both equal to TMPnow. However, a difference E (t) is generated between the target value TMP ₁ and the predicted value TMP ₂ at time Tnext after Tp has elapsed from the current time Tnow. Therefore, the air volume control unit 452 calculates the operation amount u (t) of the blower 412 based on the difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t). Since the air volume control unit 452 controls the blower 412 using two parameters (proportional gain Kp and integral gain Ki), parameter adjustment can be performed easily and simply.

Although the air volume control unit 452 performs PI control, PID (Proportional-Integral-Derivative) control may be performed. In this case, since the air volume control unit 452 calculates the operation amount u (t) of the blower 412 in consideration of the differential value of the difference E (t), more stable control can be performed.

FIG. 5 is a flowchart showing the processing of the target value acquisition unit 451 in the first embodiment. This flowchart is executed by the target value acquisition unit 451 when the filtration operation is resumed after the separation membrane 407 is cleaned with the chemical solution.

First, the target value acquisition unit 451 receives the initial value TMP ₀ of the membrane differential pressure from the pressure gauge 410 (step S10). Next, the target value acquisition unit 451 determines whether or not the closing index k, the upper limit value TMPlim, and the maintenance cycle L are input by the operator (step S11). The operator inputs these values using the input unit 460.

When the closing index k, the upper limit value TMPlim, and the maintenance cycle L are input by the operator (step S11: YES), the target value acquisition unit 451 determines the parameter A based on the above-described equation (4) or equation (5). Is calculated (step S12). Thereafter, the target value acquisition unit 451 calculates the target value TMPref (t) of the film differential pressure by solving the differential equation of the above-described mathematical expression (3) (step S13). The target value acquisition unit 451 stores the calculated target value TMPref (t) in the memory in the control device 450, and ends the processing according to this flowchart.

FIG. 6 is a flowchart showing the processing of the predicted value acquisition unit 453 in the first embodiment. First, the predicted value acquisition unit 453 receives the treated water flow rate Q ₁ (t) from the flow meter 411 (step S20). Next, the predicted value acquisition unit 453 receives the air volume Q ₂ (t) of the blower 412 from the flow meter 416 (step S21).

The predicted value acquisition unit 453 calculates the flux J (t) by dividing the flow rate Q ₁ (t) by the membrane area Ma of the separation membrane 407 (step S22). Thereafter, the predicted value acquisition unit 453 calculates the parameter Am (t) based on the above mathematical formula (10) (step S23). Here, the flux X ₁ (t) in Equation (10) is the flux J (t), and the air volume X ₂ (t) is the air volume Q ₂ (t) received in step S21.

Next, the predicted value acquisition unit 453 calculates the predicted value TMPhat (t) of the membrane differential pressure by solving the differential equation of the above formula (6) (step S24). The predicted value acquisition unit 453 stores the calculated predicted value TMPhat (t) in the memory in the control device 450, and ends the processing according to this flowchart.

FIG. 7 is a flowchart showing processing of the air volume control unit 452 in the first embodiment. First, the air volume control unit 452 reads the target value TMPref (t) calculated by the target value acquisition unit 451 in step S13 of FIG. 5 from the memory in the control device 450 (step S30). Next, the air volume control unit 452 reads the predicted value TMPhat (t) calculated by the predicted value acquisition unit 453 in step S24 of FIG. 6 from the memory in the control device 450 (step S31).

Next, the air volume control unit 452 calculates a difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t) based on the above equation (11) (step S32). The air volume control unit 452 calculates the operation amount u (t) of the blower 412 based on the above equation (12) using the calculated difference E (t) (step S33). The air volume control unit 452 controls the air volume of the blower 412 based on the calculated operation amount u (t) (step S34). When the adjustment of the air volume is completed, the air volume control unit 452 ends the process according to this flowchart.

As described above, the air volume control unit 452 supplies the air supplied from the air diffuser 414 toward the separation membrane 407 based on the difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t). To control the airflow. Thereby, the difference between the actual membrane differential pressure of the separation membrane 407 and the target value TMPref (t) can be reduced, and the amount of air supplied to the separation membrane 407 can be calculated appropriately.

In addition, the aeration tank 400 may be a biological treatment tank structure for carrying out A2O (Anaerobic Anoxic Oxic) in which a separation membrane 407 is installed. Specifically, the biological treatment tank has an anaerobic region in which neither oxygen (O ₂ ) nor bound oxygen (NO ₃ etc.) exists, an anoxic region in which oxygen does not exist but bound oxygen exists, and oxygen exists. You may divide | segment into Qi region. This allows biological nitrogen and phosphorus removal.

In addition, in the present embodiment, a separation membrane 407 may be installed in a biological treatment tank structure for carrying out an AO (Anaerobic Oxic) method, a circulating nitrification denitrification method, and a flocculant addition method.

(Second Embodiment)
In the first embodiment, the air volume control unit 452 performs PI control or PID control. On the other hand, in the second embodiment, the air volume control unit 452 performs rule-based control. Specifically, the air volume control unit 452 controls the air volume of air supplied by the blower 412 in a stepwise manner with reference to the table TB. A change value Δu (t) of the operation amount of the blower 412 is set in the table TB.

For example, when the predicted value TMPhat (t) is smaller than the target value TMPref (t) of the film differential pressure TMP (t), the air volume control unit 452 needs to reduce the air volume of the blower 412.
For this reason, when the predicted value TMPhat (t) is smaller than the target value TMPref (t) of the membrane pressure difference TMP (t), the change value Δu (t) set in the table TB is a negative value.

On the other hand, when the predicted value TMPhat (t) is larger than the target value TMPref (t) of the film differential pressure TMP (t), the air volume control unit 452 needs to increase the air volume of the blower 412. For this reason, when the predicted value TMPhat (t) is larger than the target value TMPref (t) of the membrane pressure difference TMP (t), the change value Δu (t) set in the table TB is a positive value.

The table TB is set so that the change value Δu (t) of the operation amount of the blower 412 becomes larger as the difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t) is larger. The According to such rule-based control, even an operator with little experience and knowledge about control can easily adjust control parameters.
Even when the present embodiment is adopted, the air volume determined by the rule-based control is not maintained at a constant value for a predetermined control period, but the average value during the control period becomes the determined air volume. Thus, the blower 412 can be controlled in a vibration manner with a shorter period.

(Third embodiment)
In the first and second embodiments, the air volume control unit 452 performs PI control, PID control, or rule-based control. On the other hand, in the third embodiment, the air volume control unit 452 performs extreme value control. The extreme value control is a control for expressing efficiency, profit, loss, etc. imposed on the system as one evaluation function and maintaining the value of the evaluation function at the maximum or minimum.

In this embodiment, the air volume control unit 452 performs extreme value control using the evaluation function EV shown in Expression (13). Tnow is the current time, and Tp is the elapsed time from the current time Tnow. For example, Tp is set to 1 day (24 hours).

As shown in Equation (13), the evaluation function EV is the sum of squares of prediction errors from the current time Tnow to the time point when Tp has elapsed. The air volume control unit 452 performs extreme value control so as to minimize the evaluation function EV. The extreme value control is control for searching for the optimum operation amount so that the evaluation function is minimized while increasing or decreasing the operation amount (the air volume of the blower 412) in a predetermined cycle. Therefore, the air volume control unit 452 automatically searches for the optimum air volume of the blower 412 while increasing or decreasing the air volume of the blower 412 at a predetermined cycle.

According to this embodiment, the air volume control unit 452 can calculate the evaluation function EV using one integrator. For this reason, the air volume control unit 452 can be realized using a simple controller such as a PLC controller.
Even in the case of adopting the present embodiment, the air volume determined by the extreme value control is not maintained at a constant value during a predetermined control period, but the average value during the control period becomes the determined air volume. Thus, the blower 412 can be controlled in a vibration manner with a shorter period.

(Fourth embodiment)
In the first embodiment, the predicted value acquisition unit 453 calculates the parameter Am (t) based on the flux X1 (t) and the air volume X2 (t), as shown in Equation (10). On the other hand, in the fourth embodiment, the predicted value acquisition unit 453 uses not only the flux X ₁ (t) and the air volume X ₂ (t) but also the measured values other than these to further improve the parameter Am (t). Calculate well.

FIG. 8 is a block diagram of the sewage treatment system 10 of the fourth embodiment. As shown in FIG. 8, the thermometer 417 is connected to the air volume control unit 452. The thermometer 417 is a sensor for measuring the water temperature Te (t) in the aeration tank 400. The thermometer 417 transmits the measured water temperature Te (t) to the air volume control unit 452.

As shown in the equation (14), the parameters Am (t) included in the prediction models of the equations (6) and (9) include coefficients a ₁ to a ₃ , a flux X ₁ (t), and an air volume X ₂ ( t) and the water temperature X ₃ (t). The water temperature X ₃ (t) is the water temperature Te (t) in the aeration tank 400 measured by the thermometer 417.

For example, in summer when the water temperature is high, microorganisms are likely to adhere to the separation membrane 407. Further, in winter when the water temperature is low, microorganisms hardly adhere to the separation membrane 407. Therefore, even when the clogging state of the separation membrane 407 changes due to the water temperature, the parameter Am (t) can be calculated with high accuracy.
For this reason, the difference between the target value TMPref (t) of the membrane differential pressure and the predicted value TMPhat (t) of the membrane differential pressure can be further reduced.

Further, the predicted value acquisition unit 453 may calculate the parameter Am (t) based on Expression (15) in order to calculate the parameter Am (t) more accurately. Here, n is an integer of 4 or more. _{Further, a} 1 ~ a _n is a _{coefficient, X 1 (t) ~ X} n (t) is a plurality of measurement values relating to the clogging of the separation membrane 407.

The predicted value acquisition unit 453 generates time series data for a predetermined period from the past operation data of the variable TMP predicted as the variables X ₁ (t) to X _n (t) that cause clogging of the separation membrane. And apply one of the coefficients a ₁ to a by applying one of the least square method, partial least square method, total least square method, generalized least square method, regularized least square method, support vector regression, and fit vector regression _n is determined.

The plurality of measured values X ₁ (t) to X _n (t) include various measured values in addition to the flux X ₁ (t), the air volume X ₂ (t), and the water temperature X ₃ (t). For example, the plurality of measured values X ₁ (t) to X _n (t) are at least one of MLSS (Mixed Liquor Suspended Solid) concentration, auxiliary air diffusion amount, coagulant injection amount, circulation pump flow rate, and return pump flow rate. May be included. In addition, a plurality of measured values X ₁ (t) to X _n (t) are the dissolved oxygen concentration of wastewater or treated water, ORP (Oxidation-Reduction Potential), pH, EEM (Excitation Emission Matrix), absorbance, BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), TOC (Total Organic Carbon), at least one of ammonia concentration, nitric acid concentration, phosphoric acid concentration, total nitrogen concentration, total phosphorus concentration, soluble COD concentration, and soluble BOD concentration May be included. Further, the plurality of measurement values X ₁ (t) to X _n (t) may include a composite variable obtained by performing four arithmetic operations on variables representing these measurement values.

As described above, the predicted value acquisition unit 453 provides various measured values as well as the flux X ₁ (t) of the treated water flowing through the pipe 409 and the air volume X ₂ (t) of the air supplied by the blower 412. The predicted value TMPhat (t) of the membrane differential pressure is calculated using this. As a result, the actual membrane differential pressure of the separation membrane 407 can be made closer to the target value TMPref (t), and the amount of air supplied to the separation membrane can be calculated appropriately.

(Fifth embodiment)
In the first embodiment, as shown in FIG. 2, a separation membrane unit in which the separation membrane 407 and the diffuser 414 are integrated is used. On the other hand, in the fifth embodiment, an example in which the separation membrane 407 is used alone will be described.

FIG. 9 is a diagram showing processing performed in the aeration tank 400 of the fifth embodiment. As shown in FIG. 9, the aeration tank 400 of the present embodiment does not include the blower 412, the pipe 413, the air diffuser 414, and the flow meter 416.

The separation membrane 407 is washed with air supplied from the aeration unit 404. Therefore, the predicted value acquisition unit 453 calculates the predicted value TMPhat (t) based on the flow meter 406 instead of the flow meter 416. The air volume control unit 452 controls the air volume of the blower 402 instead of the blower 412.

As described above, in the present embodiment, the blower 412, the pipe 413, the aeration unit 414, and the flow meter 416 are not arranged in the aeration tank 400, and air for the aeration unit 404 to clean the separation membrane 407 is used. It was decided to supply. Thereby, cost reduction of the sewage treatment system 10 can be achieved.

(Sixth embodiment)
In the first embodiment, the air volume control unit 452 performs PI control or PID control. On the other hand, in the sixth embodiment, the sewage treatment system 10 newly includes a blower control unit 417 that calculates the operation amount V (t) based on the operation amount u (t) calculated by the air volume control unit 452. The blower control unit 417 (aeration control unit) controls the blower 412.

Here, the outline of the sixth embodiment will be described. Normally, in the air volume control, the operation amount of a predetermined air volume is calculated by PI or PID calculation, and the valve and the rotation speed of the blower 412 are operated by another PI control so as to supply the air volume by the calculated air volume operation amount. Cascade control is performed (see, for example, FIG. 10). At this time, in the normal PI or PID control, the operation amount u (t) of the air volume calculated by the air volume control calculation by the PI (D) control of the upper (air volume control unit 452 in FIG. 10) is lower (in FIG. 10). The control target value for the PI (D) control of the blower control unit 417) is maintained at a constant value during the control cycle (Tc_up) of the upper control. However, in cleaning and aeration control for suppressing fouling, increasing the air flow change (dispersion) increases the shearing force applied to the membrane surface, which may be preferable for suppressing fouling. Therefore, in the sixth embodiment, the operation amount u (t) of the air volume is changed in a vibration manner in a cycle shorter than the upper control cycle (Tc_up), and the operation amount V ( Control is performed so that t) coincides with the operation amount u (t) of the air volume calculated by the higher-level PI (D) control. The operation amount V (t) of the air volume is vibrated at a period equal to or higher than the lower control period (Tc_cn), and the amplitude of the vibration is determined according to the load on the blower 412. By performing such control, fouling can be more efficiently suppressed. Details will be described below.

FIG. 10 is a block diagram of the sewage treatment system 10 of the sixth embodiment. As shown in FIG. 6, the configuration differs from that shown in FIG. 3 in that the sewage treatment system 10 is provided with a blower control unit 417. Since other configurations are the same as those in FIG. 3, the blower control unit 417 will be described. Note that the blower control unit 417 may be provided in the control device 450.
The blower control unit 417 controls the blower 412 based on the operation amount u (t) calculated by the air volume control unit 452. A specific operation of the blower control unit 417 will be described with reference to FIG.

FIG. 11 is a diagram for explaining the operation of the blower control unit 417 in the sixth embodiment.
In FIG. 11, T1 represents the control period of the air volume control unit 452, and a1 represents the manipulated variable u (t). Here, a1 is the operation amount u (t) calculated by the air volume control unit 452 using the above equation (12). That is, the operation amount u (t) is calculated at the control cycle T1. Therefore, the blower control unit 417 calculates an operation amount V (t) in which the operation amount of the average air volume matches the operation amount u (t) during the control period T1 based on the operation amount u (t). At this time, the blower control unit 417 manipulates the operation amount V (t) so as to vibrate at a cycle shorter than the control cycle T1 of the air volume control unit 452 and the control cycle T2 of the operation end (valve, rotation speed) of the blower 412. Is calculated. The manipulated variable V (t) is a2 in FIG. Although FIG. 11 shows a configuration in which control is performed at a constant control cycle T2, the blower control unit 417 may perform control at irregular control cycles. Further, the blower control unit 417 calculates that the manipulated variable V (t) is different in the period equal to or greater than the control period T2 if the manipulated variable of the average air volume matches the manipulated variable u (t) during the control period T1. Alternatively, it may be calculated so that a part thereof is different.

According to the present embodiment, the operation amount is not constant within the control period of the air volume control unit 452, is less than the control period of the air volume control unit 452, and the operation end (valve, rotation speed) of the blower 412 that performs air volume control. Control is performed by oscillating at a cycle equal to or greater than the control cycle Tc_cn. Therefore, fouling can be suppressed more efficiently.

(Seventh embodiment)
In the first embodiment, the air volume control unit 452 performs PI control on the blower 412 using the difference E (t) calculated based on the above equation (11). On the other hand, in the seventh embodiment, the air volume control unit 452 controls the blower 412 by operating in a control mode determined according to the absolute value error and the current control mode of the air volume control unit 452. In the seventh embodiment, the air volume control unit 452 has a normal control mode and a constant air volume control mode. The normal control mode is a mode in which the blower 412 is controlled with the operation amount u (t) calculated by the above equation (12) as in the first embodiment. The constant air volume control mode is a mode in which the blower 412 is controlled with the operation volume of the air volume fixed. The operation amount used in the constant air volume control mode may be set in advance.

The air volume control unit 452 in the seventh embodiment determines a control mode based on the control mode determination table shown in FIG. 12, and operates in the determined control mode. FIG. 12 is a diagram illustrating a specific example of the control mode determination table. As shown in FIG. 12, information on the control mode for each combination of the magnitude of the absolute value error and the current control mode is registered in the control mode determination table. For example, in the control mode determination table shown in FIG. 12, when the absolute value error is greater than or equal to the threshold value TH1 (absolute value error ≧ TH1) and the current control mode is the normal control mode, switching to the constant air volume control mode is performed. Is represented. That is, in this case, the air volume control unit 452 determines its own control mode as the constant air volume control mode, and performs control by switching the control mode. Further, it is shown that the constant air volume control mode is maintained when the absolute value error is equal to or greater than the threshold value TH1 (absolute value error ≧ TH1) and the current control mode is the constant air volume control mode. That is, in this case, the air volume control unit 452 determines its own control mode as the constant air volume control mode, and performs control while maintaining the control mode.

Here, the absolute stationary error is an absolute value error between the target value TMPref (t) obtained from the target value obtaining unit 451 and the predicted value TMPhat (t) obtained from the predicted value obtaining unit 453. In the present embodiment, the normal variation range of the error around the target value is represented by, for example, standard deviation σ, the threshold value TH1 is TH1 = k × σ (a set value of about k = 2 to 4), and the threshold value TH2 is TH2 = k ′. Xσ (k ′ <k) is preferable. In addition, the operation amount u (t) of the fixed air amount in the constant air amount control mode is set to a value that is somewhat higher, assuming a safe side when the input changes suddenly and a large amount of cleaning air is required. It is preferable.

According to the present embodiment, the air volume control unit 452 determines the control mode according to the absolute value error and the current control mode, and performs control in the determined control mode. Therefore, it can respond according to the situation.

In this embodiment, when it is desired to perform control more finely than the above, the constant air volume control is divided into an air volume constant control having a value higher than the set value and an air volume constant control having a value lower than the set value. The air volume control unit 452 may be configured to determine the control mode according to the above conditions. An example will be described. In the control mode determination table shown in FIG. 12, the absolute value error is greater than or equal to the threshold value TH1 (absolute value error ≧ TH1), the current control mode is the normal control mode, and the absolute value error is the target value TMPref (t). If the air flow control unit 452 shifts excessively in the downward direction, the air flow control unit 452 switches to the air flow constant control mode having a value lower than the set value after separately diagnosing and confirming that the individual sensor of the input variable is not an abnormal value. In the control mode determination table shown in FIG. 12, the absolute value error is greater than or equal to the threshold value TH1 (absolute value error ≧ TH1), the current control mode is the normal control mode, and the absolute value error is the target value TMPref (t ) Or the individual sensor of the input variable has an abnormal value, the air volume control unit 452 switches to the air volume constant control mode having a value higher than the set value.

(Eighth embodiment)
In the first embodiment, the blower 412 is controlled, but in many MBR processes, the air volume control (auxiliary aeration control) by the blower 402 for performing biological treatment and the air volume control for cleaning the MBR process film ( The operation of the air volume control unit 452 in each of the above embodiments corresponds to the operation of the cleaning aeration control. The main purpose of the cleaning aeration is to clean the membrane, but the cleaning aeration also serves as an oxygen supply for performing the biological treatment, and the supply of oxygen necessary for the biological treatment is often insufficient only with the amount of the cleaning air. Therefore, supplemental aeration compensates for oxygen supply shortage. In each of the above embodiments, the purpose is to supply the cleaning air volume that is the minimum necessary from the viewpoint of membrane cleaning. However, when the air volume required for the film cleaning is extremely small, it is sufficient to perform biological treatment with only auxiliary aeration. Oxygen supply may not be possible.

On the other hand, the eighth embodiment addresses the above problem. In the eighth embodiment, the air volume control unit 452 calculates a difference value of the operation amount of the air volume based on a plurality of control methods, and controls the air volume using any of the calculated difference values. Here, as a plurality of control methods, there are a normal control method and a density maintenance control method. The normal control method is a method of calculating the operation amount u (t) by the above equation (12) as in the first embodiment. The concentration maintenance control method is a method of calculating the operation amount by the same calculation method as that of auxiliary aeration in order to maintain the DO concentration target value.

The amount of oxygen required for biological treatment is usually managed by the dissolved oxygen concentration (DO concentration). In some cases, the quality of treated water, for example, ammonia concentration may be used for management. However, even in that case, the DO concentration is often controlled in terms of the DO concentration necessary to maintain the predetermined ammonia concentration, but in this embodiment, the required oxygen amount is the DO concentration or ammonia concentration. It is assumed that it is managed by some kind of index. The DO concentration is measured by a sensor (not shown). Here, for simplification of explanation, a case where the required acid amount is managed by DO concentration will be described as an example as a method adopted by many processing facilities. At this time, the DO concentration target value is given by the operator, and the blower 402 corresponding to the auxiliary aeration is controlled by the PI (D) control or the like.

If the cleaning air volume becomes extremely small, even if the maximum air volume of the blower 402 is supplied, the target value of a given DO concentration of the blower 402 that performs auxiliary aeration may not be maintained. The actual DO concentration falls below the DO concentration target value. Therefore, when the DO concentration target value-DO concentration exceeds a predetermined threshold value, the air volume control unit 452 is in a control mode (DO mode) that maintains the DO concentration, which is a mode different from the normal operation mode (normal control mode). Control mode). This control can be easily realized by normal PI (D) control. By having such a mode switching for cleaning and aeration control, it is possible to always ensure an oxygen supply amount necessary for biological treatment.

On the other hand, when the cleaning aeration control is switched from the normal control mode to the DO control mode, the timing for returning from the DO control mode to the normal control mode is also important. This is because, if the cleaning aeration control is controlled for the purpose of supplying the oxygen amount necessary for biological treatment, a rapid increase in the membrane differential pressure is allowed depending on conditions. For that purpose, the air volume control unit 452 calculates the cleaning aeration control in the normal control mode in parallel when operating in the DO control mode, and the operation amount of the air volume calculated thereby is the DO control mode. When the operation amount of the air volume calculated when operating is reduced, the air volume necessary for the original film cleaning can be supplied by returning to the normal control mode.

In order to realize the above series of functions with simple logic, two types of control methods are used: the normal control method and the same control method as the auxiliary aeration (for example, the DO control method) for the amount of air flow in the cleaning aeration control. And then follow the flowchart of FIG. Specific processing will be described using a flowchart. FIG. 13 is a flowchart showing the processing of the air volume control unit 452 in the eighth embodiment. It is assumed that the DO target value and the DO measurement value are input to the control device 450 at the start of the processing in FIG.

The air volume control unit 452 calculates the operation amount QB1 of the cleaning air volume by the normal control method, and calculates a difference value ΔQB1 from the previously determined operation amount of the air volume (step S60). Here, the operation amount QB1 of the cleaning air amount corresponds to the operation amount u calculated by the above equation (12). Next, the air volume control unit 452 calculates the operation amount QB2 of the cleaning air volume by the same method as the auxiliary aeration, and calculates a difference value ΔQB2 from the previously determined operation amount of the air volume (step S61). Thereafter, the air volume control unit 452 determines whether or not the blower 412 has the maximum output and the difference value between the DO target value and the DO measurement value is equal to or greater than a threshold value (step S62). When the blower 412 has the maximum output and the difference value between the DO target value and the DO measurement value is greater than or equal to the threshold (step S62: YES), the air volume control unit 452 calculates ΔQB = MAX (ΔQB1, ΔQB2) (step S62). S63). The air volume control unit 452 then adds the calculated ΔQB to the previously determined air volume operation amount to determine the current cleaning air volume operation amount (step S64). The air volume control unit 452 controls the blower 412 based on the determined operation amount of the cleaning air volume.
On the other hand, if the blower 412 is not at the maximum output, or if the difference value between the DO target value and the DO measurement value is less than the threshold (step S62: NO), the air volume control unit 452 sets ΔQB to ΔQB1 (step S65). . Thereafter, the air volume control unit 452 executes the process of step S64.

According to this embodiment, even when the amount of air necessary for membrane cleaning is extremely small, it is possible to ensure the supply of oxygen necessary for biological treatment.

In addition, in order to suppress frequent switching between the two types of control methods, there is a restriction on the cycle for switching the control mode, and the difference from the previous cleaning aeration amount is calculated instead of a method for directly calculating the cleaning aeration air volume. Needless to say, it is preferable to adopt the method (speed type control).
In the present embodiment, the configuration in which the process of step S63 is executed when the blower 412 has the maximum output and the difference value between the DO target value and the DO measurement value is greater than or equal to the threshold value is shown. If the blower 412 has the maximum output, the difference value between the DO target value and the DO measurement value is greater than or equal to the threshold value, and continues for a predetermined time (for example, about 10 minutes to several tens of minutes), step S63 is performed. You may be comprised so that a process may be performed.

According to at least one embodiment described above, air supplied from the air diffuser 414 toward the separation membrane 407 based on the difference E (t) between the target value TMPref (t) and the predicted value TMPhat (t). By having the air volume control unit 452 that controls the air volume of air, the difference between the actual membrane differential pressure of the separation membrane 407 and the target value TMPref (t) can be reduced.

It should be noted that all of the TMP membrane differential pressure described in this specification may be replaced with membrane filtration resistance. Although membrane filtration resistance cannot generally be measured directly, it is known that it is represented by the formula (16) as a general formula.

In Equation (16), TMP is a membrane differential pressure [kPa], μ is a viscosity coefficient [kPa / d], J is a flux [m / d], R is a membrane filtration resistance [1 / m], and P is a power constant. is there. By transforming Equation (16), Equation (17) is obtained. The controller 450 calculates the membrane filtration resistance R based on the mathematical formula (17).

The power constant P is usually an adjustment parameter set between 1 and 2. The control device 450 functioning as a flux calculating unit calculates the flux J by dividing the value of the flow meter 411 (the amount of membrane filtered water) by the membrane area. Since continuous measurement is possible, assuming that the viscosity coefficient μ is constant, a value obtained by dividing the membrane differential pressure TMP by the power of the flux J corresponds to the membrane filtration resistance R.

That is, as shown in Equation (18), the control device 450 functioning as a membrane filtration resistance calculation unit calculates the membrane filtration resistance R based on the measured values of the membrane differential pressure TMP and the flux J.
In Equation (18), B is a constant.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

Claims (16)

1. Acquire at least one of the target value of the membrane differential pressure and membrane filtration resistance after the measurement of the initial value based on at least one of the membrane differential pressure and membrane filtration resistance of the separation membrane that filters activated sludge A target value acquisition unit to
   Based on a measurement value related to clogging of the separation membrane, a predicted value acquisition unit that acquires at least one of the predicted values of the membrane differential pressure and membrane filtration resistance after the measurement value is measured;
   An air volume that controls an air volume of air supplied from the air diffuser toward the separation membrane based on the target value acquired by the target value acquiring unit and the predicted value acquired by the predicted value acquiring unit. A control unit;
   A wastewater treatment control device.
2. The target value acquisition unit includes one of the initial value TMP ₀ of the membrane differential pressure and the membrane filtration resistance, one of the membrane differential pressure and / or the upper limit value TMPlim of the membrane filtration resistance, a maintenance cycle L, and a clogging index. calculating a parameter A based on k, and calculating at least one of the target values of the TMP (t) of the membrane differential pressure and membrane filtration resistance based on Equation (1),
   

   

   The wastewater treatment control apparatus according to claim 1.
3. When k = 1, the target value acquisition unit calculates the parameter A based on Equation (2),
   

   

   When k> 1, the target value acquisition unit calculates the parameter A based on Equation (3).
   

   

   The wastewater treatment control apparatus according to claim 2.
4. The predicted value acquisition unit calculates a parameter Am (t) based on a measurement value related to the clogging of the separation membrane, and calculates the calculated parameter Am (t) and the flux J of the treated water filtered by the separation membrane. (T) and the blockage index k are used to calculate at least one of the predicted values of the membrane differential pressure and the membrane filtration resistance TMP (t) based on Equation (4).
   

   

   The wastewater treatment control apparatus according to claim 1.
5. The predicted value acquisition unit uses a number n of measured values related to clogging of the separation membrane, a plurality of measured values X1 (t) to Xn (t) related to clogging of the separation membrane, and coefficients a1 to an Calculating the parameter Am (t) based on (5),
   

   

   The wastewater treatment control apparatus according to claim 4.
6. The plurality of measured values related to the clogging of the separation membrane include a flux of the treated water and an air volume or an air magnification of air supplied from the diffuser toward the separation membrane.
   The wastewater treatment control apparatus according to claim 5.
7. The plurality of measured values related to the clogging of the separation membrane are further the water temperature, MLSS concentration, auxiliary air diffusion amount, coagulant injection amount, circulation pump flow rate, return pump flow rate, dissolved oxygen concentration of the sewage or dissolved water of the treated water. Variables representing oxygen concentration, ORP, pH, EEM, absorbance, BOD, COD, TOC, ammonia concentration, nitric acid concentration, phosphoric acid concentration, total nitrogen concentration, total phosphorus concentration, soluble COD concentration, and soluble BOD concentration, And at least one of at least one synthetic variable obtained by arithmetically calculating at least a plurality of these variables.
   The wastewater treatment control apparatus according to claim 6.
8. The predicted value acquisition unit is based on a plurality of measured values related to the clogging of the separation membrane, based on least square method, partial least square method, total least square method, generalized least square method, regularized least square method, support vector regression The coefficients a1 to an are calculated using any one of fit vector regression.
   The wastewater treatment control apparatus according to claim 5.
9. The air volume control unit performs any one of PI control, PID control, rule-based control, or extreme value control based on the difference between the target value and the predicted value, thereby removing the separation membrane from the diffusion unit. To control the air volume of air supplied toward
   The wastewater treatment control apparatus according to claim 1.
10. Manipulation of the air volume supplied from the air diffuser to the separation membrane based on the air volume manipulated air supplied from the air diffuser to the separation membrane calculated by the air volume controller It further includes an aeration control unit that newly calculates the amount,
    The air diffusion control unit calculates an operation amount so as to vary the operation amount in a cycle shorter than the control cycle during a control cycle in which the operation amount of the air flow rate obtained from the air volume control unit is calculated.
    The wastewater treatment control apparatus according to claim 1.
11. The wastewater treatment control according to claim 10, wherein the air diffusion control unit calculates an operation amount so that an operation amount of an average air volume during the control period coincides with an operation amount of an air volume obtained from the air volume control unit. apparatus.
12. The air volume control unit is configured to fix the air volume operation amount in a first mode in which the air diffuser is controlled with the air volume operation amount obtained based on the target value and the predicted value. And a second mode for controlling the air diffuser, and performing control in either the first mode or the second mode according to a predetermined condition.
    The wastewater treatment control apparatus according to claim 1.
13. The air volume control unit is a method for supplying oxygen necessary for biological treatment, and a difference value between an operation amount of the air volume and an operation volume of the previous air volume obtained based on the target value and the predicted value. On the basis of the operation amount of the air flow rate obtained based on the difference between the operation amount of the air flow and the operation amount of the previous air flow, the larger difference value of the difference values at the time of the maximum output of the air diffuser is the value of the previous air flow rate. Add to the operation amount to control the air volume.
    The wastewater treatment control apparatus according to claim 1.
14. A separation membrane for filtering sewage,
    An air diffuser for supplying air toward the separation membrane;
    A membrane differential pressure measuring unit for measuring a membrane differential pressure of the separation membrane;
    Based on the initial value of the membrane differential pressure measured by the membrane differential pressure measurement unit, a target value acquisition unit that acquires a target value of the membrane differential pressure after the measurement of the initial value;
    Based on a measurement value related to clogging of the separation membrane, a predicted value acquisition unit that acquires a predicted value of the membrane differential pressure after the measurement of the measurement value;
    Based on the target value acquired by the target value acquisition unit and the predicted value acquired by the predicted value acquisition unit, an air volume control unit that controls the air volume of air supplied by the air diffuser,
    Equipped with a wastewater treatment system.
15. A separation membrane for filtering sewage,
    An air diffuser for supplying air toward the separation membrane;
    A membrane differential pressure measuring unit for measuring a membrane differential pressure of the separation membrane;
    A flow meter for measuring the amount of membrane filtration water;
    A flux calculation unit for calculating the flux by dividing the amount of membrane filtrate by the membrane area;
    Based on the membrane differential pressure measured by the membrane differential pressure measurement unit and the flux calculated by the flux calculation unit, a membrane filtration resistance calculation unit that calculates membrane filtration resistance;
    Based on the initial value of the membrane filtration resistance calculated by the membrane filtration resistance calculation unit, a target value acquisition unit that acquires a target value of the membrane filtration resistance after the measurement of the initial value;
    Based on a measurement value related to clogging of the separation membrane, a predicted value acquisition unit that acquires a predicted value of the membrane filtration resistance after the measurement value is measured, and
    Based on the target value acquired by the target value acquisition unit and the predicted value acquired by the predicted value acquisition unit, an air volume control unit that controls the air volume of air supplied by the air diffuser,
    Equipped with a wastewater treatment system.
16. The membrane filtration resistance calculation unit is configured to multiply the membrane differential pressure measured by the membrane differential pressure measurement unit by a constant to a value obtained by dividing the membrane differential pressure by the power of the flux calculated by the flux calculation unit. The waste water treatment system according to claim 15, wherein

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