WO2017056696A1

WO2017056696A1 - Water treatment system

Info

Publication number: WO2017056696A1
Application number: PCT/JP2016/072712
Authority: WO
Inventors: 佳記西田; 一郎山野井; 剛武本; 信幸中村
Original assignee: 株式会社日立製作所
Priority date: 2015-09-28
Filing date: 2016-08-03
Publication date: 2017-04-06
Also published as: CN108025935B; JP6499952B2; CN108025935A; JP2017064568A

Abstract

This water treatment system 1 is provided with: a water treatment apparatus 2 which is equipped with multiple trains comprising reaction tanks (4-1, 4-2), including an aerobic tank, and air diffusing parts (6-1, 6-2), and which has dissolved oxygen (DO) meters installed in all of the multiple trains, flow meters (11-1, 11-2) for measuring the flow rates of to-be-treated water flowing into the respective trains, a water quality meter 10 installed in the aerobic tank 4-1 disposed in one of the trains, and a blower 7; and an air volume control part 3 that controls the volume of air to be fed to the respective trains. The air volume control unit 3 controls the volume of air to be fed to the aforementioned one train on the basis of a measurement by the water quality meter 10, and, at the same time, controls the volume of air to be fed to the other train(s) on the basis of DO concentration measurements and the flow rate of the to-be-treated water flowing into at least one of the one train and the other train(s).

Description

Water treatment system

The present invention relates to a water treatment system that includes a water treatment device using activated sludge and controls the water treatment device.

In water treatment plants (water treatment devices) including sewage treatment plants, various water treatment processes have been introduced to remove environmental pollutants. The standard activated sludge method, which is a general treatment method, mainly targets removal of organic substances. In recent years, advanced treatment aimed at removing nitrogen (particularly ammonia nitrogen) and phosphorus has been promoted in order to further reduce the environmental burden.
Organic substances, ammoniacal nitrogen (NH ₄ -N), and phosphorus are mainly removed in an aerobic state in which dissolved oxygen (hereinafter referred to as DO) is present. For example, ammonia nitrogen is removed by a reaction (nitrification) that oxidizes to nitrate nitrogen (NO ₃ -N) by nitrifying bacteria in an aerobic state. For this reason, in sewage treatment, sufficient oxygen supply (aeration) is required to realize an appropriate quality of treated water, but from the viewpoint of energy saving, it is also required to suppress excessive aeration and reduce power consumption.
Various aeration control methods have been proposed for the purpose of stably achieving a desired treated water quality and reducing power consumption. For example, constant air volume control that controls the aeration air volume constant, air magnification control that controls based on the ratio of the aeration air volume to the inflow sewage flow rate, DO control that controls based on the DO concentration (dissolved oxygen concentration) of the aerobic tank, etc. Has been. In recent years, there has been an increasing trend to implement ammonia control using an ammonia meter that has improved accuracy and controlling based on the measured ammoniacal nitrogen concentration. Since ammonia nitrogen, which is a processing target, is measured, followability to the processing target value is improved as compared with conventional DO control and the like, and a more appropriate control of the aeration air volume becomes possible.

The number of ammonia meters installed at the sewage treatment plant is small, and it is often necessary to purchase a new ammonia meter, resulting in maintenance work such as calibration and new consumables costs. Therefore, in order to reduce the number of instruments installed, a method has been proposed in which the installation of instruments is limited to the representative series, and the control target in the series where no instrument is installed is set based on the control objective in the representative series. ing. For example, in Patent Document 1, an ammonia meter is installed in only one system, and a dissolved oxygen concentration meter (DO meter) is installed in all systems, and in a system in which an ammonia meter is installed, the air volume is based on the measured value of the ammonia meter. In the other series, the air volume is controlled so that the DO concentration is equivalent to that in the series where the ammonia meter is installed.

Japanese Patent No. 4131955

In Patent Document 1, an ammonia meter is installed, and the air volume is controlled so that the DO concentration of the series in which the air volume is controlled based on the measurement value of the ammonia gauge and the other series are equal. However, the amount of treatment by microorganisms varies depending on the treatment time (residence time: also referred to as HRT). For this reason, even if the series has the same DO concentration, if the processing time (residence time) differs depending on conditions such as the inflow flow rate to each series, the processing amount varies depending on the series. There is a possibility that the effect of control by the measuring instrument (ammonia meter) installed in the plant cannot be obtained sufficiently.
Therefore, the present invention corrects the setting of the aeration air volume in the other multiple series based on the DO concentration in the representative series where the water quality meter is installed, based on the inflow flow rate of the treated water to each series, so An object of the present invention is to provide a water treatment system that can optimally control the amount of treated water or the amount of aeration air.

In order to solve the above problems, the water treatment system of the present invention includes a reaction tank including at least an aerobic tank and a plurality of systems having a diffuser provided in the aerobic tank, and is installed in all the plurality of systems. A dissolved oxygen concentration meter that measures the dissolved oxygen concentration in the aerobic tank, a flow meter that measures the flow rate of the water to be treated flowing into the reaction tank of each series, or a flow rate estimation unit that estimates the flow rate of the treated water A water treatment device having a water quality meter installed in the aerobic tank of one series, and a blower for supplying air to the aeration section of each series, and from the blower to the aeration section of each series An air volume control unit for controlling the air volume of the supplied air, and the air volume control unit controls the air volume to one series in which the water quality meter is installed based on the measurement value of the water quality meter, and At least one of one sequence and the other sequence Based on the measured value of the existing oxygen concentration, the inflow flow rate of the treated water of one series where the water quality meter of the one series is installed, and the inflow flow rate of the treated water of at least one series of the other series, Controlling the air volume to at least one of the other sequences.

According to the present invention, based on the dissolved oxygen concentration (DO concentration) in the representative series where the water quality meter is installed, the setting of the aeration air volume in the other multiple series is corrected based on the inflow rate of the water to be treated into each series. Thus, it is possible to provide a water treatment system that can optimally control the treatment amount or aeration air amount for the water to be treated in each series.

Issues, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic whole block diagram of the water treatment system of Example 1 which concerns on one Example of this invention. It is a functional block diagram of the air volume control part shown in FIG. It is a processing flow figure of the target air volume calculating part which comprises the air volume control part shown in FIG. It is a processing flow figure of the dissolved oxygen concentration (DO density | concentration) target value calculating part which comprises the air volume control part shown in FIG. It is a processing flow figure of the air volume valve opening calculating part which comprises the air volume control part shown in FIG. It is a schematic whole block diagram of the water treatment system of Example 2 which concerns on the other Example of this invention. It is a functional block diagram of the air volume control part shown in FIG. It is a processing flow figure of the 1st target air volume calculating part which constitutes the air volume control part shown in FIG. It is a processing flow figure of the 2nd target air volume calculating part which constitutes the air volume control part shown in FIG. It is a processing flow figure of the air volume valve opening calculating part which comprises the air volume control part shown in FIG. It is a processing flowchart of the 2nd target air volume calculating part which comprises the air volume control part of Example 3 which concerns on the other Example of this invention. It is a process flow figure of the air volume valve opening calculating part 33 which comprises the air volume control part of Example 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, the schematic whole block diagram of the water treatment system of Example 1 which concerns on one Example of this invention is shown. In FIG. 1, the solid line indicates piping, and the dotted line indicates a signal line. The water treatment system 1 which concerns on a present Example is the water treatment apparatus 2 which removes organic substance and ammonia nitrogen using sewage (treated water), such as domestic waste water or industrial wastewater, in a standard activated sludge method. And the air volume control part 3 is provided.
(Water treatment equipment)
As shown in FIG. 1, the water treatment apparatus 2 includes a series 1 composed of an aerobic tank (reaction tank) 4-1 and a final sedimentation tank 5-1 in order from the inflow side of sewage to be treated. Similarly, in order from the inflow side of sewage to be treated water, a series 2 comprising an aerobic tank (reaction tank) 4-2 and a final sedimentation tank 5-2 is provided, and series 1 and series 2 are activated sludge. The same treatment method using, that is, a standard activated sludge method is used. Further, the aerobic tank (reaction tank) 4-1 in the series 1 is provided with a plurality of air diffusers 6-1 and the aerobic tank (reaction tank) 4-2 in the series 2 is provided with a plurality of air diffusers 6-1. -2 is provided.
The sewage which is the treated water flows into the aerobic tank (reaction tank) 4-1 of the series 1 through the inflow pipe 14 and the series 1 inflow pipe 14-1 branched from the inflow pipe 14, and the return pump 9 -1 is installed, the return sludge flows from the final sedimentation basin 5-1 through the series 1 return sludge pipe 17-1, and ammonia nitrogen (NH ₄ -N) is nitrated by the nitrifying bacteria in the activated sludge. Nitrification is performed to oxidize to nitrogen (NO ₃ —N). In addition, organic matter oxidation by aerobic heterotrophic bacteria is performed.
Similarly, the sewage water to be treated flows into the aerobic tank (reaction tank) 4-2 of the series 2 through the inflow pipe 14 and the series 2 inflow pipe 14-2 branched from the inflow pipe 14. Return sludge flows from the final sedimentation basin 5-2 through the series 2 return sludge pipe 17-2 where the return pump 9-2 is installed, and ammonia nitrogen (NH ₄ -N) is produced by nitrifying bacteria in the activated sludge. Nitrification is performed to oxidize nitrile to nitrate nitrogen (NO ₃ —N). In addition, organic matter oxidation by aerobic heterotrophic bacteria is performed.

The final sedimentation basin 5-1 of series 1 and the final sedimentation basin 5-2 of series 2 are facilities for settling and separating the supernatant liquid and the activated sludges 16-1 and 16-2 by gravity sedimentation. The supernatant liquid after settling and separation is discharged out of the system as treated water through the series 1 outflow pipe 15-1 and the series 2 outflow pipe 15-2, respectively.
The final sedimentation tank 5-1 and the final sedimentation tank 5-2 are provided with sludge scrapers (not shown) that scrape the activated sludges 16-1 and 16-2 that settle on the bottom surface. The sludge scraper has a plurality of flights attached to the chain at predetermined intervals, at both ends of the drive shaft to which the rotational force is transmitted by the drive device installed on the water surface of the final sedimentation tanks 5-1 and 5-2. The drive sprocket wheel provided, the driven sprocket wheel provided at both ends of the intermediate shaft disposed downstream of the drive sprocket wheel, the downstream of the driven sprocket wheel provided at both ends of the intermediate shaft, and the final settling basin 5 -1,5-2 Driven sprocket wheels provided at both ends of the tail shaft and near the bottom surfaces of the final sedimentation tanks 5-1 and 5-2 and provided at both ends of the tail shaft A driven sprocket wheel is provided at both ends of the head shaft disposed on the upstream side of the driven sprocket wheel. A chain to which a plurality of flights are attached at predetermined intervals is stretched in parallel with these drive sprocket wheel and driven sprocket wheel, and is circulated by a drive device. The flight has a flat plate shape that is attached at predetermined intervals so as to cross the chain stretched in parallel with the two strips. When the chain moves along the direction from the downstream side to the upstream side of the final sedimentation tanks 5-1 and 5-2, the bottom surface of the final sedimentation tanks 5-1 and 5-2 is caused by the flight attached to the chain. The activated sludges 16-1 and 16-2 that settle on the sludge are raked into the sludge pit. The activated sludges 16-1 and 16-2 raked into the sludge pits are returned by the return pumps 9-1 and 9-2 through the series 1 return sludge pipe 17-1 and the series 2 return sludge pipe 17-2, respectively. Then, it is returned to the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 and again subjected to a series of biological treatments.

As shown in FIG. 1, the plurality of air diffusers 6-1 provided in the aerobic tank (reaction tank) 4-1 in the series 1 are connected via the series 1 aeration pipe 18-1 and the air volume valve 8-1. Air is supplied to the aerobic tank (reaction tank) 4-1, connected to the blower 7. Similarly, the plurality of aeration units 6-2 provided in the aerobic tank (reaction tank) 4-2 in the series 2 are connected to the blower 7 via the series 2 aeration pipe 18-2 and the air volume valve 8-2. The air is supplied to the aerobic tank (reaction tank) 4-2. A series 1 air distribution pipe 18-1 connecting the air diffuser 6-1 and the air flow valve 8-1, and an air flow meter 13-1 is installed on the air flow valve 8-1 side. The air volume measurement value of the air flowing through the series 1 aeration pipe 18-1 measured by the above is output to the air volume control unit 3 through a signal line.
In addition, a flow meter 11-1 is installed in the series 1 inflow pipe 14-1 which branches from the inflow pipe 14 and is connected to the series 1 aerobic tank (reaction tank) 4-1, and is measured by the flow meter 11-1. The measured value of the inflow flow rate of the sewage that is the treated water flowing into the aerobic tank (reaction tank) 4-1 is output to the air volume control unit 3 through the signal line. Similarly, a flow meter 11-2 is installed in the series 2 inflow pipe 14-2 that branches from the inflow pipe 14 and is connected to the series 2 aerobic tank (reaction tank) 4-2. The measured value of the inflow flow rate of sewage that is treated water flowing into the measured aerobic tank (reaction tank) 4-2 is output to the air volume control unit 3 through a signal line. Here, the flow meter 11-1 and the flow meter 11-2 also function as a flow rate estimation unit. The aerobic tank (reaction tank) 4-1 in series 1 is provided with an ammonia meter 10 and a dissolved oxygen concentration meter (DO meter) 12-1 as water quality meters, and the ammonia nitrogen concentration measured by the ammonia meter 10 The measured value of the dissolved oxygen concentration (DO concentration) measured by the dissolved oxygen concentration meter (DO meter) 12-1 is output to the air volume control unit 3 through a signal line. Further, a dissolved oxygen concentration meter (DO meter) 12-2 is installed in the aerobic tank (reaction tank) 4-2 in series 2, and the dissolved oxygen concentration measured by the dissolved oxygen concentration meter (DO meter) 12-2. The measured value of the concentration (DO concentration) is output to the air volume control unit 3 via the signal line.
(Air volume control unit)
FIG. 2 is a functional block diagram of the air volume control unit 3 shown in FIG. As shown in FIG. 2, the air volume control unit 3 stores a target air volume calculating unit 31, a DO concentration target value calculating unit 32, an air volume valve opening calculating unit 33, a measured value acquiring unit 34, and at least various calculation formulas described in detail later. Storage section 35, input I / F 36, and output I / F 37, which are connected to each other via an internal bus 38. A target air volume calculation unit 31 for calculating a target air volume of air that flows through the series 1 air distribution pipe 18-1 and is supplied from the air diffuser 6-1 to the aerobic tank (reaction tank) 4-1 of the series 1; The DO concentration target value calculation unit 32 for calculating the target value of the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-2, and the blower 7 and the series 1 aeration unit 6-1 The opening command value to the air flow valve 8-1 installed in the series 1 air distribution pipe 18-1 and the series 2 air diffusion pipe 18-2 connecting the blower 7 and the series 2 air diffusion section 6-2. The air flow valve opening calculation unit 33 for calculating the opening command value for the air flow valve 8-2 installed in the PC is, for example, a processor such as a CPU (not shown), a ROM storing various programs, and data of calculation processes temporarily. Is realized by a storage device such as a RAM and an external storage device, and a processor such as a CPU By reading and executing the various programs stored in the OM, it stores the result of calculation execution result RAM or the external storage device. Note that the calculation result or calculation process data may be stored in the storage unit 35 instead of the RAM.

As shown in FIG. 2, the input I / F 36 includes a measured value of ammonia nitrogen concentration measured by an ammonia meter 10 installed in a series 1 aerobic tank (reaction tank) 4-1, a flow meter (series 1). ) Measured value of the inflow flow rate of sewage that is the treated water flowing into the aerobic tank (reaction tank) 4-1 measured by 11-1, an aerobic tank measured by the flow meter (series 2) 11-2 (Reaction tank) Measured value of the inflow flow rate of sewage to be treated into 4-2, dissolved oxygen concentration meter (DO meter) 12- installed in the aerobic tank (reaction tank) 4-1 of series 1 Measured value of dissolved oxygen concentration (DO concentration) measured by 1 and dissolved oxygen concentration meter (DO meter) 12-2 installed in aerobic tank (reaction tank) 4-2 of series 2 Measured value of dissolved oxygen concentration (DO concentration) measured by concentration (DO meter), and series 1 aeration pipe The air volume meter 13-1 installed at 8-1 to enter the air volume measurement value measured. In FIG. 2, the measurement values from the respective measuring instruments are shown as signal wirings superimposed on one signal line, but this is shown in this way for the convenience of description of the drawings. Are signal wirings input in parallel to the input I / F 36 via signal lines provided for the respective measuring instruments.
The output I / F 37 outputs the opening command value to the air flow valve 8-1 installed in the series 1 air distribution pipe 18-1, and the air flow valve 8 installed in the system 2 air distribution pipe 18-2. Output the opening command value to -2. The details of the target air volume calculation unit 31, the DO concentration target value calculation unit 32, the air volume valve opening calculation unit 33, and the measurement value acquisition unit 34 will be described later.

Next, the outline | summary of operation | movement of the water treatment system 1, ie, the water treatment apparatus 2, and the air volume control part 3, is demonstrated below.
First, the flow meter 11-1 that also functions as a flow rate estimation unit has an inflow of sewage that is treated water flowing into the aerobic tank (reaction tank) 4-1 of the series 1 through the series 1 inflow pipe 14-1. The flow meter 11-2 that measures the flow rate and also functions as a flow rate estimation unit similarly flows into the aerobic tank (reaction tank) 4-2 of the series 2 via the series 2 inflow piping 14-2. Measure the inflow of sewage, which is water. The dissolved oxygen concentration meter (DO meter) 12-1 installed in the series 1 aerobic tank (reaction tank) 4-1 is used to calculate the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-1. The dissolved oxygen concentration meter (DO meter) 12-2, which is measured and installed in the series 2 aerobic tank (reaction tank) 4-2, is used for the dissolved oxygen concentration (DO) in the aerobic tank (reaction tank) 4-2. Concentration).
The air volume control unit 3 is configured so that the ammonia nitrogen concentration in the aerobic tank (reaction tank) 4-1 measured by the ammonia meter 10 as a water quality meter installed in the series 1 aerobic tank (reaction tank) 4-1. Based on the measured value, the target air volume for series 1 is obtained and set. For series 2, the air volume control unit 3 performs sewage treatment water flowing into the series 1 aerobic tank (reaction tank) 4-1 measured by the flow meter 11-1 and the flow meter 11-2, respectively. Inflow rate, inflow rate of sewage that is treated water flowing into a series 2 aerobic tank (reaction tank) 4-2, and a series 1 aerobic measured by a dissolved oxygen concentration meter (DO meter) 12-1. Based on the dissolved oxygen concentration (DO concentration) in the tank 4-1, the target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 is obtained and set.

Next, the outline of the air volume control for the series 1 and the series 2 will be described. The air volume control unit 3 selects the series air flow according to the difference between the air volume measurement value measured by the air volume meter 13-1 installed in the series 1 air diffusion pipe 18-1 and the target air volume to the set series 1 described above. The opening degree of the air volume valve 8-1 installed in the one air diffusion pipe 18-1 is controlled. For series 2, the air volume control unit 3 performs the aerobic tank (reaction) measured by the dissolved oxygen concentration meter (DO meter) 12-2 installed in the aerobic tank (reaction tank) 4-2 of the series 2. Tank) The measured value of the dissolved oxygen concentration (DO concentration) in 4-2 and the target value of the dissolved oxygen concentration (DO concentration) in the set series 2 aerobic tank (reaction tank) 4-2 described above. Based on the difference, the opening degree of the air volume valve 8-2 installed in the series 2 aeration pipe 18-2 is controlled.
A method for setting the target air volume for the series 1 in the air volume controller 3 will be described below. The air volume control unit 3 performs feedback control so that the ammonia nitrogen concentration in the series 1 aerobic tank (reaction tank) 4-1 measured by the ammonia meter 10 approaches a desired ammonia nitrogen concentration target value. Sets the target air volume for series 1. The setting of the target air volume for the series 1 follows the following formulas (1) and (2).

Here, QB 1 — _set (t) [m ³ / min]: target air volume setting value for series 1 at time t, NH ₄ (t) [mg−N / L]: aerobic tank of series 1 at time t ( (Reaction tank) 4-1 ammonia nitrogen concentration in NH ₄ , NH _4tgt [mg-N / L]: ammonia nitrogen concentration target value, Δt [min]: data collection interval (sampling interval), K _P [m ³ (gas ) · M ³ (water) / (g−N · min)]: proportional gain, T _i [min]: integration time.

The method for setting the target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 by the air flow control unit 3 will be described below. The amount of decrease in ammonia nitrogen concentration due to nitrification is the product of nitrification rate and treatment time (residence time: HRT). The nitrification rate is a function of the dissolved oxygen concentration (DO concentration) as shown in the following formula (3). When the dissolved oxygen concentration (DO concentration) is high, the nitrification rate increases. Therefore, if the inflow flow rate of sewage, which is the water to be treated, is large and the treatment time (residence time: HRT) is shortened, it is considered necessary to increase the dissolved oxygen concentration (DO concentration) and increase the nitrification rate. Therefore, in the air volume control unit 3, the aerobic tank (reaction tank) 4-1 measured by the dissolved oxygen concentration meter (DO meter) 12-1 installed in the series 1 aerobic tank (reaction tank) 4-1. The dissolved oxygen concentration (DO concentration) was measured by the flow meter 11-1 installed in the series 1 inflow piping 14-1 and the flow meter 11-2 installed in the series 2 inflow piping 14-2, respectively. Measured value of inflow of sewage that is treated water to series 1 aerobic tank (reaction tank) 4-1, sewage that is treated water to series 2 aerobic tank (reaction tank) 4-2 The target value of dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-2 of the series 2 is obtained and set so as to correct the difference in the measured value of the inflow amount. The target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 is set according to the following equation (3). *

_{Here, DO 2_set (t) [mg} / L]: aerobic tank in sequence 2 at time t the concentration of dissolved oxygen (reaction tank) in 4-2 (DO concentration) the target _{value, DO 1 (t) [mg} / L]: dissolved oxygen concentration (DO concentration) in series 1 aerobic tank (reaction tank) 4-1 at time t, Q in — _i (t) [m ³ / min]: series i aerobic tank at time t The inflow flow rate (i = 1 or 2) of sewage to be treated water into the (reaction tank), β, m [−]: coefficient.

Further, the air volume control unit 3 sets the opening degree of the air volume valve 8-1 installed in the series 1 air diffuser 18-1 and the air volume valve 8-2 installed in the series 2 air diffuser 18-2 as follows. Control is performed based on the equations (4) to (6). The opening degree of the air volume valve 8-1 is controlled so that the air volume to the series 1 approaches the set value of the target air volume to the series 1 set by the air volume control unit 3. The opening degree of the air volume valve 8-2 is that the dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 is set in the series 2 aerobic tank (reaction tank). ) Control so that the dissolved oxygen concentration (DO concentration) in 4-2 approaches the target value. *

Here, VO _i (t) [-]: Opening degree of air volume valve 8-i at time t (i = 1 or 2), QB ₁ (t) [m ³ / min]: To series 1 at time t _Airflow measurement value, QB 1 — _set (t) [m ³ / min]: target _airflow setting value for series 1 at time t, DO ₂ (t) [mg / L]: series 2 aerobic tank (reaction at time t) measured value of the dissolved oxygen concentration in the bath) in 4-2 (DO _{concentration), DO 2_set (t) [} mg / L]: aerobic tank in sequence 2 at time t (dissolved oxygen concentration in the reaction vessel) in 4-2 (DO concentration) the target value, Δt [min]: data collection interval (sampling _{^{interval), K P_1 [min / m}} 3]: proportional gain on the sequence _{1, K P_2 [L / mg} ]: proportional gain in sequence 2 , T I — _i [min]: integration time in series i (i = 1 or 2).

As described above, in this example, based on the measured value of the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) of the series in which the air volume control using a water quality meter (for example, an ammonia meter) is executed. In addition, the dissolved oxygen in the aerobic tank (reaction tank) of the above other series based on the difference in the flow rate of sewage that is the treated water to the series where the water quality meter is installed and the other series where the water quality meter is not installed Set the density (DO density) target value. Thereby, it can suppress that the amount of processing and the amount of aeration air become insufficient or excessive depending on the series, and a desired treated water quality can be secured stably.

Below, the detail of the process by the target air volume calculating part 31, the DO density | concentration target calculating part 32, and the air volume valve opening degree calculating part 33 which comprise the air volume control part 3 is demonstrated.
(Target air volume calculation unit)
FIG. 3 is a process flow diagram of the target air volume calculation unit 31 constituting the air volume control unit 3.
As shown in FIG. 3, the measured value of the ammoniacal nitrogen concentration NH ₄ (t) at time t, measured by the ammonia meter 10 installed in the aerobic tank (reaction tank) 4-1 of the series 1, is The data is taken into the measurement value acquisition unit 34 (FIG. 2) via the input I / F 36 and the internal bus 38. The measurement value acquisition unit 34 transfers the measured value of the ammonia nitrogen concentration NH ₄ (t) at the time t taken to the target air volume calculation unit 31 via the internal bus 38. Thereby, the target air volume calculation unit 31 acquires the measured value of the ammonia nitrogen concentration NH ₄ (t) at the time t in the series 1 aerobic tank (reaction tank) 4-1 (step S11).
Subsequently, in step S12, the target air volume calculation unit 31 accesses the storage unit 35 via the internal bus 38, and reads the ammonia nitrogen concentration target value NH _4tgt (series 1) stored in advance in the storage unit 35. .

The target air volume calculating unit 31 calculates the difference between the measured value of the ammonia nitrogen concentration NH ₄ (t) at time t acquired in step S11 and the ammonia nitrogen concentration target value NH _4tgt read from the storage unit 35 in step S12. e (t) is calculated (step S13). Here, the difference e (t) can be obtained by executing the arithmetic expression (2) described above. As described above, the expression (2) is stored in the storage unit 35 in advance, and the target air volume calculation unit 31 reads and executes the expression (2) that is the calculation expression. Instead of this, equation (2) may be incorporated in advance as a program and stored in a ROM (not shown).
In step S14, the target air volume calculating unit 31 calculates the target air volume to the series 1 aerobic tank (reaction tank) 4-1 based on the difference e (t) calculated in step S13, that is, the series 1 aeration pipe. 18-1 is calculated by calculating the above-mentioned equation (1). Similarly to the above, Expression (1) may be stored in the storage unit 35 in advance, or Expression (1) may be incorporated as a program and stored in a ROM (not shown).
In step S 15, the target air volume calculation unit 31 stores the calculated target air volume to the series 1 aerobic tank (reaction tank) 4-1 in a predetermined storage area of the storage unit 35 via the internal bus 38. Instead of step S15, the calculated target air volume to the aerobic tank (reaction tank) 4-1 of the series 1 may be transferred to the air volume valve opening calculation unit 33 described later via the internal bus 38. good.
(DO concentration target value calculator)
FIG. 4 is a process flow diagram of the DO concentration target value calculation unit 32 constituting the air volume control unit 3.
As shown in FIG. 4, a series 1 aerobic tank at time t measured by a dissolved oxygen concentration meter (DO meter) 12-1 installed in a series 1 aerobic tank (reaction tank) 4-1. The measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) in the (reaction tank) 4-1 is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) in the series 1 aerobic tank (reaction tank) 4-1 at the time t taken via the internal bus 38. Transfer to the DO concentration target value calculator 32. Thereby, the DO concentration target value calculation unit 32 acquires the measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) at the time t in the series 1 aerobic tank (reaction tank) 4-1 (Step S1). S21).

Subsequently, in step S22, the water to be treated that flows into the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the flow meter 11-1 installed in the series 1 inflow piping 14-1. The measured value of the inflow flow rate Q in — ₁ (t) of the sewage is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₁ (t) of sewage that is the treated water flowing into the series 1 aerobic tank (reaction tank) 4-1 at the time t taken in, to the internal bus 38. And transferred to the DO concentration target value calculation unit 32. Thereby, the DO concentration target value calculation unit 32 acquires a measured value of the inflow flow rate Q in — ₁ (t) of sewage (treated water) to the series 1 at time t.
In step S23, sewage that is treated water flowing into the series 2 aerobic tank (reaction tank) 4-2 at time t, measured by the flow meter 11-2 installed in the series 2 inflow piping 14-2. The measured value of the inflow flow rate Q in — ₂ (t) is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₂ (t) of the sewage that is the treated water flowing into the series 2 aerobic tank (reaction tank) 4-2 at the time t taken in the internal bus 38. And transferred to the DO concentration target value calculation unit 32. Thereby, the DO concentration target value calculation unit 32 acquires a measured value of the inflow flow rate Q in — ₂ (t) of sewage (treated water) to the series 2 at time t. Note that steps S21 to S23 may be executed in parallel.

In step S24, the DO concentration target value calculator 32 calculates the dissolved oxygen concentration (DO concentration) DO ₁ (t) at time t in the series 1 aerobic tank (reaction tank) 4-1 acquired in step S21. Measured value, measured value of inflow flow rate Q in — ₁ (t) of sewage (treated water) to series 1 at time t acquired in step S22, and sewage to series 2 at time t acquired in step S23 ( Based on the measured value of the inflow flow rate Q in — ₂ (t) of the water to be treated, a target value of dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-2 of the series 2 is calculated. Here, the DO concentration target value calculation unit 32 calculates the dissolved oxygen concentration (DO concentration) target value in the series 2 aerobic tank (reaction tank) 4-2 by calculating the above equation (3). To do. Equation (3) may be stored in advance in the storage unit 35, or equation (3) may be incorporated as a program and stored in a ROM (not shown).
In step S25, the DO concentration target value calculation unit 32 stores the calculated dissolved oxygen concentration (DO concentration) target value in the series 2 aerobic tank (reaction tank) 4-2 via the internal bus 38. Stored in a predetermined storage area. Instead of step S25, the calculated dissolved oxygen concentration (DO concentration) target value in the aerobic tank (reaction tank) 4-2 of the series 2 is supplied to an air flow valve opening degree calculation unit described later via the internal bus 38. Alternatively, the data may be transferred to 33.
(Airflow valve opening calculator)
FIG. 5 is a process flow diagram of the air volume valve opening calculation unit 33 constituting the air volume control unit 3.
As shown in FIG. 5, the airflow valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38 and is stored in the storage unit 35 in the series 1 aerobic tank (reaction tank) 4-1. The target air volume QB 1 — _set (t) is read (step S31). Here, the target air volume QB _{1_set} (t) to the series 1 aerobic tank (reaction tank) 4-1 stored in the storage unit 35 is the target air volume calculated by the target air volume calculating unit 31 (see FIG. 3).
In step S32, the air volume measurement value QB ₁ (QB ₁ ) to the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the air volume meter 13-1 installed in the series 1 air diffusion pipe 18-1. t), that is, the air volume measurement value at the time t flowing through the series 1 aeration pipe 18-1 is taken into the measurement value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the air volume measurement value QB ₁ (t) to the aerobic tank (reaction tank) 4-1 of the series 1 at the time t taken into the air volume opening degree calculation unit 33 via the internal bus 38. Forward. As a result, the air volume opening calculation unit 33 acquires the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t.

In step S33, the air volume valve opening calculator 33 calculates the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t obtained in step S32, and step S31. The difference e ₁ (t) from the target air volume QB _{1 — set} (t) to the aerobic tank (reaction tank) 4-1 of the series 1 obtained in _step ( ₁ ) is calculated. Here, the difference e ₁ (t) is calculated by the above-described equation (5) being executed by the air flow valve opening degree calculation unit 33.
In step S34, the series 2 aerobic tank (reaction tank) at time t, measured by a dissolved oxygen concentration meter (DO meter) 12-2 installed in the series 2 aerobic tank (reaction tank) 4-2. ) The measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) in 4-2 is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the series 2 aerobic tank (reaction tank) 4-2 at the time t taken through the internal bus 38. Transfer to the air flow valve opening calculator 33. Thereby, the air quantity valve opening calculating unit 33 acquires the measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the series 2 aerobic tank at time t.

In step S35, the air volume valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and stores in the series 2 aerobic tank (reaction tank) 4-2 at time t stored in the storage unit 35. The dissolved oxygen concentration (DO concentration) target value DO 2 — _set (t) is read out. Here, the dissolved oxygen concentration (DO concentration) target value DO _{2_set} (t) in the series 2 aerobic tank (reaction tank) 4-2 at time t, which is stored in the storage unit 35, is the DO concentration target described above. It is a dissolved oxygen concentration (DO concentration) target value (FIG. 4) calculated by the value calculation unit 32.
In step S36, the air volume valve opening calculator 33 calculates the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the series 2 aerobic tank at time t acquired in step S34, and step S35. The difference e ₂ (t) from the dissolved oxygen concentration (DO concentration) target value DO _{2 — set} (t) in the series 2 aerobic tank (reaction tank) 4-2 at time t obtained in _step (b) is calculated. Here, the difference e ₂ (t) is calculated by the above-described equation (6) being executed by the air flow valve opening degree calculation unit 33.

In step 37, the air volume valve opening calculator 33 calculates the opening degree measured value VO ₁ (t) at the time t of the air volume valve 8-1 installed in the series 1 aeration pipe 18-1, and the series 2 aeration pipe. The opening measurement value VO ₂ (t) at the time t of the air flow valve 8-2 installed in 18-2 is taken in via the input I / F 36, the measurement value acquisition unit 34, and the internal bus 38.

At step S38, the opening degree measurement value _VO 1 of Kazeryouben 8-1 series 1 taken at step S37 (t), opening the measurement value _VO 2 of Kazeryouben 8-2 series 2 (t), step Based on the difference e ₁ (t) obtained in S33 and the difference e ₂ (t) obtained in step S36, the air flow valve opening calculator 33 opens the opening of the series 1 air flow valve 8-1. And the opening degree of the air volume valve 8-2 of the series 2 is calculated. Here, the opening degree of the series 1 air volume valve 8-1 and the opening degree of the series 2 air volume valve 8-2 are calculated by the above-described equation (4) being executed by the air volume valve opening degree calculation unit 33. .
In step S39, the air volume valve opening calculator 33 uses the opening of the series 1 air volume valve 8-1 and the opening of the series 2 air volume valve 8-2 calculated in step S38 as command values, respectively. It outputs to the air volume valve 8-1 of the series 1 and the air volume valve 8-2 of the series 2 via the bus 38 and the output I / F 37.

As described above, a water quality meter (for example, an ammonia meter) is used by operating the target air volume calculation unit 31, the DO concentration target value calculation unit 32, and the air volume valve opening calculation unit 33 that constitute the air volume control unit 3. Based on the measured value of dissolved oxygen concentration (DO concentration) of series 1 that is executing the air flow control, sewage that is treated water to series 1 where the water quality meter is installed and other series 2 where the water quality meter is not installed Based on the difference in the inflow rate, the dissolved oxygen concentration (DO concentration) target value of the other series 2 is set. An air volume valve 8-1 that adjusts the aeration air volume to the series 1 based on at least the difference between the set target value of the dissolved oxygen concentration (DO density) of the series 2 and the dissolved oxygen concentration (DO density) of the series 2; By controlling the opening of the air volume valve 8-2 that adjusts the aeration air flow to the series 2, it is possible to suppress the processing amount and the aeration air volume from being insufficient or excessive depending on the series, and to stably provide the desired treated water quality. It can be secured.

In the present embodiment, the water treatment apparatus 2 using the standard activated sludge method has been described as an example. However, the present invention is not limited to this, and an aerobic tank such as an anaerobic aerobic activated sludge method or a circulating nitrification denitrification method is used. Any other processing method can be applied in the same manner. Moreover, in this example, in order to make the explanation easy to understand, an ammonia meter as a water quality meter and a dissolved oxygen concentration meter (DO meter) are installed in an aerobic tank (reaction tank), and a dissolved oxygen concentration meter ( (DO meter) only in the aerobic tank (reaction tank) and the two lines with the line 2 are targeted, but even in the water treatment apparatus having three lines or more, if the treatment method in each line is the same Can be applied as well.

In this embodiment, the flow meter 11-1 is installed in the series 1 inflow piping 14-1 and the flow meter 11-2 is installed in the series 2 inflow piping 14-2. It is not necessary to install a flow meter for each series. For example, one flow meter is installed upstream from a branch point for each series (a branch point branching from the inflow pipe 14 to each series), and an inflow flow rate of sewage that is treated water flowing into the inflow pipe 14 is measured. The flow rate of each series may be calculated based on a preset distribution ratio. Furthermore, it is good also as a structure which prepares the database which stores the past inflow flow volume actual data which is a to-be-processed water which flows into each series, without installing a flowmeter, and estimates the flow volume of each series. In this case, the component that estimates the flow rate of each series is referred to as a flow rate control unit. In the following, unless otherwise specified, the flow meter can be replaced with a flow rate estimation unit.

In this embodiment, the air flow to the series 1 and the series 2 is controlled by the air volume valve 8-1 and the air volume valve 8-2, respectively. However, in the case of the blower 7 capable of air volume control such as inlet vane control, the blower is also combined. 7 may be controlled, and when the blower 7 is installed for each series, the air quantity to the series 1 and the series 2 may be controlled only by the blower 7.
In the present embodiment, the case where the ammonia meter 10 is used as the water quality meter is assumed assuming application to nitrification control. However, for example, the present invention is also applicable to a system that performs control related to organic matter removal, nitrogen removal, or phosphorus removal. Is possible. In this case, as a water quality meter, nitrate nitrogen concentration, total nitrogen concentration, phosphoric acid phosphorus concentration, total phosphorus concentration, BOD (Biochemical Oxygen Demand), COD _Mn (oxygen demand by potassium permanganate), COD _Cr (nichrome) A measuring instrument that measures the organic substance concentration such as oxygen demand by potassium acid) or TOC (Total Organic Carbon) may be used.

In this embodiment, the ammonia meter 10 is installed in the series 1 aerobic tank (reaction tank) 4-1, and the target air volume for the series 1 is set in a feedback manner. Does not matter. For example, an ammonia meter 10 is installed upstream of a series 1 aerobic tank (reaction tank) 4-1, and the ammonia nitrogen concentration of the sewage that is the treated water flowing into the aerobic tank (reaction tank) 4-1. It is good also as a structure which measures and sets the target air volume to the series 1 in feedforward based on the measured ammoniacal nitrogen concentration. The ammonia meter 10 may be installed downstream of the aerobic tank (reaction tank) 4-1.
In the present embodiment, the target air volume for the series 1 is set based on the measured value of the ammonia nitrogen concentration measured by the ammonia meter 10, but the present invention is not limited to this. For example, based on the measurement value of the ammonia nitrogen concentration measured by the ammonia meter 10, the target value of dissolved oxygen concentration (DO concentration) in the series 1 aerobic tank (reaction tank) 4-1 is set, and the dissolved The air volume is controlled based on the difference between the target value of oxygen concentration (DO concentration) and the measured value of the dissolved oxygen concentration meter (DO meter) 12-1 installed in the aerobic tank (reaction tank) 4-1. good. In this case, it is not always necessary to install the ammonia meter 10 in the aerobic tank (reaction tank) 4-1, for example, ammonia removal performance and dissolved oxygen in the aerobic tank (reaction tank) 4-1. Prepare a database that stores the relationship of concentration (DO concentration) in advance based on past performance data. By referring to this database, dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-1 It is good also as a structure which sets a target value.

In the present embodiment, the dissolved oxygen concentration (DO concentration) target value in the series 2 aerobic tank (reaction tank) 4-2 and the series 2 aerobic tank (reaction tank) 4-2 are installed. However, the present invention is not limited to this. For example, in the same manner as the anemometer 13-1 installed in the series 1 aeration pipe 18-1, an anemometer is installed in the series 2 aeration pipe 18-2, and a series 2 aerobic tank (reaction tank) 4- 2 based on the difference between the target air volume set so as to satisfy the target value of dissolved oxygen concentration (DO concentration) in 2 and the air volume measured by the anemometer installed in the series 2 aeration pipe 18-2. You may comprise so that the opening degree of may be controlled.
In the present embodiment, as shown in FIG. 4, the DO concentration target calculation unit 32 performs the dissolved oxygen concentration (DO concentration) DO ₁ in the series 1 aerobic tank (reaction tank) 4-1 at time t. With respect to the measured value of (t), the measured value of the sewage (treated water) inflow rate Q in — ₁ (t) to series 1 at time t and the inflow rate Q of sewage (treated water) to series 2 at time t. _Target of dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-2 of series 2 by multiplying the function related to the inflow rate ratio by the measured value of _{in_2} (t) (the above-mentioned formula (3)) Although the configuration is such that the value is calculated and set, the present invention is not limited to this. For example, measurement of the sewage inflow rate _{Q IN_2} of the sewage into the system 2 in the measurement value and the time t of the inlet flow _{Q IN_1} of (water to be treated) (t) (treated water) (t) to the system 1 at time t Other functions relating to the value may be used, for example, the measured value of the inflow flow rate Q in — ₁ (t) of the sewage (treated water) to the series 1 at the time t and the sewage (treated) to the series 2 at the time t. You may multiply the function which _{concerns on} the difference of the measured value of inflow flow rate _{Qin_2} (t) of water. Further, the sewage (treated water) to the series 1 at the time t with respect to the measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) in the series 1 aerobic tank (reaction tank) 4-1 at the time t. ) Inflow rate Q in — ₁ (t) and a function relating to the measured value of inflow rate Q in — ₂ (t) of sewage (treated water) to series 2 at time t. The target value of dissolved oxygen concentration (DO concentration) in the tank (reaction tank) 4-2 may be calculated and set.

Further, since the nitrification rate is generally expressed by the following formula (7), the dissolved oxygen concentration in the series 2 aerobic tank (reaction tank) 4-2 is calculated by the arithmetic expression shown in the following formula (8). (DO concentration) A target value may be calculated and set.

Here, μ [mg−N / L / h]: nitrification rate, DO [mg / L]: DO concentration, α, K [−]: coefficient.

_{Here, DO 2_set (t) [mg} / L]: aerobic tank in sequence 2 at time t the concentration of dissolved oxygen (reaction tank) in 4-2 (DO concentration) the target _{value, DO 1 (t) [mg} / L]: DO concentration in series 1 aerobic tank (reaction tank) 4-1 at time t, Q in — _i (t) [m ³ / min]: To series i aerobic tank (reaction tank) at time t Sewage inflow (i = 1 or 2), α _i, K _i [−]: coefficient (i = 1 or 2).

In this embodiment, in the above equation (3), the measured value of the inflow flow rate Q in — ₁ (t) of the sewage (treated water) to the series 1 at the time t and the sewage (treated) to the series 2 at the time t. The measured value of the inflow flow rate Q in — ₂ (t) of water) is used to calculate and set the target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2. In addition to this, a flow meter is installed in the series 1 return sludge pipe 17-1 and the series 2 return sludge pipe 17-2, and the sewage to the series 1 at the time t as shown in the following equation (9) The _sum of the measured value of the inflow flow rate Q in — ₁ (t) of the water) and the flow rate of the return sludge flowing through the series 1 return sludge pipe 17-1, and the sewage (treated water) to the series 2 at time t flows through the measured value and sequence 2 return sludge pipe 17-2 inlet flow _{Q in_2} (t) Based on a function related to the ratio to the total flow rate of the sludge sent, the target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 may be calculated and set. . In addition, when the activated sludge mixed liquid is circulated, such as a circulation nitrification denitrification method, the circulation flow rate may be added to the flow rate term.

Here, Q _r — i [m ³ / h]: the flow rate of return sludge (i = 1 or 2) flowing through the series i return sludge piping 17-i.

In the present embodiment, in the above-described equation (3), the difference in only the inflow flow rate of sewage that is treated water flowing into each series is considered. However, MLSS (Mixed Liquid Suspended Solids) in the aerobic tank of each series is considered. Calculate and set the target value of dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2, taking into account differences in concentration (concentration of suspended solids or activated sludge suspended solids) May be. For example, an MLSS meter is installed in a series 1 aerobic tank (reaction tank) 4-1 and a series 2 aerobic tank (reaction tank) 4-2, and the above-described formula (10) is used. You may add the term regarding MLSS density | concentration to Formula (3). *

Here, MLSSi [mg / L]: MLSS concentration (i = 1 or 2) in the aerobic tank (reaction tank) 4-i of series i, β ′, n [−]: coefficient.

In the above equation (8), the coefficient α _i may be MLSSi [mg / L]: MLSS concentration (i = 1 or 2) in the series i aerobic tank (reaction tank) 4-i.
Further, in this embodiment, in the above-described equation (3), the measured value of the inflow flow rate Q in — ₁ (t) of sewage (treated water) to the series 1 at time t and the sewage (covered to the series 2 at time t). The measured value of the inflow flow rate Q in — ₂ (t) of the treated water), that is, the instantaneous value of the inflow rate of the sewage (treated water) flowing into the series 1 and the series 2, and the aerobic tank of the series 2 (reaction tank) ) Although the 4-2 dissolved oxygen concentration (DO concentration) target value is calculated and set, the average value of the inflow flow rate of sewage (treated water) for an arbitrary period may be used instead. . In addition, in the above formulas (8), (9), and (10), the measured value of the inflow flow rate of sewage (treated water) flowing into each series, the flow rate of return sludge flowing through the return sludge piping of each series Similarly, an average value of an arbitrary period may be used for the measured value of MLSS and the measured value of the MLSS concentration in the aerobic tank (reaction tank) of each series.

As described above, according to the present embodiment, the setting of the aeration air volume in the other multiple series is corrected based on the inflow rate of the treated water to each series based on the DO concentration in the representative series where the water quality meter is installed. Thus, it is possible to provide a water treatment system that can optimally control the treatment amount or aeration air amount for the water to be treated in each series.
More specifically, based on the measured value of the dissolved oxygen concentration (DO concentration) of the series in which the air volume control using a water quality meter (for example, ammonia meter) is executed, the water quality meter and the series in which the water quality meter is installed By setting the target value of dissolved oxygen concentration (DO concentration) for the other series based on the difference in the inflow flow rate of sewage, which is the treated water to other series where no meter is installed, the treatment amount and aeration are set according to the series. It is possible to suppress the air volume from becoming insufficient or excessive, and to secure a desired treated water quality stably.

FIG. 6 shows a schematic overall configuration diagram of a water treatment system of Example 2 according to another embodiment of the present invention, and FIG. 7 shows a functional block diagram of the air volume control unit shown in FIG. In the water treatment system of the present embodiment, the point having the air flow meter 13-2 installed in the series 2 aeration pipe 18-2 constituting the water treatment apparatus 2, and the air flow control unit 3a are the target in the first embodiment. Instead of the air volume calculation unit 31 and the DO concentration target value calculation unit 32, the first embodiment differs from the first embodiment in that it includes a first target air volume calculation unit 31a and a second target calculation unit 31b. The same components as those in the first embodiment are denoted by the same reference numerals, and the description overlapping with that in the first embodiment is omitted below.

As shown in FIG. 6, the water treatment apparatus 2 of the present embodiment is a series 2 sprayer that connects a diffuser 6-2 and a blower 7 provided in an aerobic tank (reaction tank) 4-2 in the series 2, respectively. An air flow meter 13-2 installed in the air pipe 18-2 is provided. Note that an air volume valve 8-2 is installed in the series 2 air diffusion pipe 18-2, and the air flow meter 13-2 is installed on the air volume valve 8-2 side of the series 2 air diffusion pipe 18-2. Has been. The flow rate of the air flowing from the blower 7 through the air flow valve 8-2 through the system 2 aeration pipe 18-2 measured by the air flow meter 13-2, that is, the air flow measurement value to the system 2 is a signal. It is output to the air volume control unit 3a via the line. About others, it is the same as that of the water treatment apparatus 2 of Example 1. FIG.

As shown in FIG. 7, the air volume control unit 3a of the present embodiment includes a first target air volume calculating unit 31a, a second target air volume calculating unit 31b, an air volume valve opening calculating unit 33, a measurement value acquiring unit 34, and at least details later. A storage unit 35 for storing various arithmetic expressions, an input I / F 36 and an output I / F 37 are connected to each other via an internal bus 38. A first target air volume calculator 31a that calculates the target air volume of air that flows through the series 1 air diffuser 18-1 and is supplied from the air diffuser 6-1 to the aerobic tank (reaction tank) 4-1 of the system 1; A second target air volume calculation unit 31b that calculates a target air volume of air that flows through the series 2 air distribution pipe 18-2 and is supplied from the air diffusion unit 6-2 to the aerobic tank (reaction tank) 4-2 of the system 2; And the opening command value to the air flow valve 8-1 installed in the series 1 air distribution pipe 18-1 connecting the blower 7 and the series 1 air diffuser 6-1 and the air blow of the blower 7 and the series 2 An air flow valve opening calculation unit 33 for calculating an opening command value for the air flow valve 8-2 installed in the series 2 aeration pipe 18-2 connected to the unit 6-2 is, for example, a CPU or the like (not shown). In a storage device such as a processor, a ROM for storing various programs, a RAM for temporarily storing calculation process data, and an external storage device Together they are realized by reading and executing the various programs by the processor such as a CPU is stored in the ROM, and stores the calculation result as an execution result RAM or the external storage device. Note that the calculation result or calculation process data may be stored in the storage unit 35 instead of the RAM.

As shown in FIG. 7, the input I / F 36 includes a measured value of ammonia nitrogen concentration measured by an ammonia meter 10 installed in a series 1 aerobic tank (reaction tank) 4-1, a flow meter (series 1). ) Measured value of the inflow flow rate of sewage that is the treated water flowing into the aerobic tank (reaction tank) 4-1 measured by 11-1, an aerobic tank measured by the flow meter (series 2) 11-2 (Reaction tank) Measured value of the inflow flow rate of sewage to be treated into 4-2, dissolved oxygen concentration meter (DO meter) 12- installed in the aerobic tank (reaction tank) 4-1 of series 1 Measured value of dissolved oxygen concentration (DO concentration) measured by 1 and dissolved oxygen concentration meter (DO meter) 12-2 installed in aerobic tank (reaction tank) 4-2 of series 2 Measured value of dissolved oxygen concentration (DO concentration) measured by concentration (DO meter) and series 1 aeration The air volume meter 13-1 installed at 18-1 entering the air volume measurement value measured.

The output I / F 37 outputs the opening command value to the air flow valve 8-1 installed in the series 1 air distribution pipe 18-1, and the air flow valve 8 installed in the system 2 air distribution pipe 18-2. Output the opening command value to -2. The details of the first target air volume calculator 31a, the second target air volume calculator 31b, the air volume valve opening calculator 33, and the measured value acquisition unit 34 will be described later.

Next, the outline | summary of operation | movement of the water treatment system 1, ie, the water treatment apparatus 2, and the air volume control part 3a is demonstrated below.
The air volume control unit 3a obtains the target air volume to the series 1 based on the measured value of the ammonia nitrogen concentration in the series 1 aerobic tank (reaction tank) 4-1 measured by the ammonia meter 10 as a water quality meter. Set. The setting method follows the above formulas (1) and (2). For series 2, the air volume control unit 3a first determines the dissolved oxygen concentration (DO concentration) in the series 2 aerobic tank (reaction tank) 4-2 according to the following formulas (11) and (12). The target air volume for series 2 is calculated so as to be the same as that of one aerobic tank (reaction tank) 4-1. As described above, if the flow rate of sewage (treated water) into the aerobic tank (reaction tank) differs for each series, there is a possibility that a difference occurs in the removal amount of ammonia nitrogen. Therefore, the flow meter 11-1 installed in the series 1 inflow pipe 14-1 and the flow meter 11 installed in the series 2 inflow pipe 14-2 with respect to the target air volume calculated by the expressions (11) and (12). -2 respectively, the inflow rate of sewage (treated water) flowing into the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2. The target air volume after correction to the series 2 is obtained and set by multiplying the coefficient for correcting the difference from the inflow rate of sewage (treated water). The target air volume setting formula after correction to series 2 is shown in formula (13).

QB 2 — _DO (t) [m ³ / min]: dissolved oxygen in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 at time t Target air volume to series 2 with similar concentrations (DO concentrations), QB 2 — _set (t) [m ³ / min]: Target air volume set value to series 2 at time t, DOi (t) [mg / L ]: Measurement value (i = 1 or 2) of dissolved oxygen concentration (DO concentration) in aerobic tank (reaction tank) 4-i of series i at time t, Δt [min]: data collection interval, K _P [ m ³ (gas) · m ³ (water) / (g · min)]: proportional gain, T _i [min]: integration time.

Here, Q in — _i (t) [m ³ / min]: the inflow flow rate of sewage (i = 1 or 2) to the aerobic tank (reaction tank) of series i at time t, γ, p [-]: Coefficient.

Further, the air volume control unit 3a determines the opening degree of the air volume valve 8-1 installed in the series 1 aeration pipe 18-1 and the air volume valve 8-2 installed in the series 2 aeration pipe 18-2. It controls based on Formula (4) and Formula (5). The opening degree of the air volume valve 8-1 is controlled so that the air volume to the series 1 approaches the set value of the target air volume to the series 1 set by the air volume control unit 3a. Further, the opening degree of the air volume valve 8-2 is controlled so that the air volume to the series 2 approaches the set value of the target air volume to the series 2 set by the air volume control unit 3a.
As described above, in this embodiment, based on the measured value of the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) of the series executing the air volume control using the water quality meter (for example, the ammonia meter). Compensate for the flow rate to the other series where the calculated water quality meter is not installed based on the difference in the inflow rate of the sewage that is the treated water to the series where the water quality meter is installed and the other series where the water quality meter is not installed Therefore, it is possible to realize appropriate air volume control to other systems where no water quality meter is installed.

Below, the detail of the process by the 1st target air volume calculating part 31a, the 2nd target air volume calculating part 31b, and the air volume valve opening degree calculating part 33 which comprises the air volume control part 3a is demonstrated.
(First target air volume calculation unit)
FIG. 8 is a process flow diagram of the first target air volume calculation unit 31a constituting the air volume control unit 3a.
As shown in FIG. 8, the processing flow of the first target air volume calculating unit 31a is the same as the processing flow of the target air volume calculating unit 31 in the first embodiment.
As shown in FIG. 8, in step S11, the ammoniacal nitrogen concentration NH ₄ (t) at time t, measured by the ammonia meter 10 installed in the series 1 aerobic tank (reaction tank) 4-1, was measured. The measurement value is taken into the measurement value acquisition unit 34 (FIG. 7) via the input I / F 36 and the internal bus 38. The measurement value acquisition unit 34 transfers the measured value of the ammonia nitrogen concentration NH ₄ (t) at the time t taken to the target air volume calculation unit 31 via the internal bus 38. As a result, the first target air volume calculating unit 31a acquires the measured value of the ammonia nitrogen concentration NH ₄ (t) at time t in the series 1 aerobic tank (reaction tank) 4-1.

Subsequently, in step S12, the first target air volume calculation unit 31a accesses the storage unit 35 via the internal bus 38, and is stored in advance in the storage unit 35 as an ammoniacal nitrogen concentration target value NH _4tgt (series 1). Is read.
The first target air volume calculating unit 31a obtains the measured value of the ammonia nitrogen concentration NH ₄ (t) at time t acquired in step S11 and the ammonia nitrogen concentration target value NH _4tgt read from the storage unit 35 in step S12. Difference e (t) is calculated (step S13). Here, the difference e (t) can be obtained by executing the arithmetic expression (2) described above. As described above, the expression (2) is stored in the storage unit 35 in advance, and the target air volume calculation unit 31 reads and executes the expression (2) that is the calculation expression. Instead of this, equation (2) may be incorporated in advance as a program and stored in a ROM (not shown).
In step S14, the first target air volume calculation unit 31a, based on the difference e (t) calculated in step S13, sets the target air volume to the series 1 aerobic tank (reaction tank) 4-1, that is, the series 1 dispersion. The target value of the air volume to be passed through the air pipe 18-1 is calculated by calculating the above equation (1). Similarly to the above, Expression (1) may be stored in the storage unit 35 in advance, or Expression (1) may be incorporated as a program and stored in a ROM (not shown).
In step S15, the first target air volume calculation unit 31a stores the calculated target air volume to the series 1 aerobic tank (reaction tank) 4-1 in a predetermined storage area of the storage unit 35 via the internal bus 38. To do. Instead of step S15, the calculated target air volume to the aerobic tank (reaction tank) 4-1 of the series 1 may be transferred to the air volume valve opening calculation unit 33 described later via the internal bus 38. good.
(Second target air volume calculation unit)
FIG. 9 is a process flow diagram of the second target air volume calculation unit 31b constituting the air volume control unit 3a.
As shown in FIG. 9, a series 1 aerobic tank at time t measured by a dissolved oxygen concentration meter (DO meter) 12-1 installed in a series 1 aerobic tank (reaction tank) 4-1. The measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) in the (reaction tank) 4-1 is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) in the series 1 aerobic tank (reaction tank) 4-1 at the time t taken via the internal bus 38. It transfers to the 2nd target air volume calculating part 31b. As a result, the second target air volume calculation unit 31b acquires the measured value of the dissolved oxygen concentration (DO concentration) DO ₁ (t) at time t in the series 1 aerobic tank (reaction tank) 4-1 (step S1). S41).

Subsequently, in step S42, a series 2 aerobic tank at time t measured by a dissolved oxygen concentration meter (DO meter) 12-2 installed in the series 2 aerobic tank (reaction tank) 4-2. The measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the (reaction tank) 4-2 is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the series 2 aerobic tank (reaction tank) 4-2 at the time t taken through the internal bus 38. It transfers to the 2nd target air volume calculating part 31b. As a result, the second target air volume calculating unit 31b acquires the measured value of the dissolved oxygen concentration (DO concentration) DO ₂ (t) at time t in the series 2 aerobic tank (reaction tank) 4-2.
In step S43, the second target air volume calculation unit 31b obtains the dissolved oxygen concentration (DO concentration) DO ₂ (t) in the series 2 aerobic tank (reaction tank) 4-2 at time t acquired in step 42. And the difference e () between the measured value of dissolved oxygen concentration (DO concentration) DO ₁ (t) at time t in the series 1 aerobic tank (reaction tank) 4-1 acquired in step S41. t) is calculated. Here, the difference e (t) is calculated by the second target air volume calculation unit 31b executing the above-described equation (12).

Next, the second target air volume calculation unit 31b accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35 in advance, the series 2 aerobic tank (reaction tank) 4-2 at time t. The target air volume setting value QB _{2 —} set (t) is read (step S44).
In step S45, the second target air volume calculation unit 31b calculates the difference e (t) calculated in step S43 and the series 2 aerobic tank (reaction tank) at time t read from the storage unit 35 in step S44. 4-2 _dissolved in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 at time t based on the target _airflow setting value QB _{2_set} (t) A target air volume QB _{2_DO} (t) for series 2 is calculated so that the oxygen concentration (DO concentration) is the same. Here, a series 2 in which dissolved oxygen concentrations (DO concentrations) in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 become similar at time t. The target air volume QB _{2_DO} (t) is calculated when the second target air volume calculating unit 31b executes the above-described equation (11).

Subsequently, the sewage (treated water) flowing into the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the flow meter 11-1 installed in the series 1 inflow pipe 14-1. The measured value of the inflow flow rate Q in — ₁ (t) is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₁ (t) of the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1 at the time t taken, Is transferred to the second target air volume calculation unit 31b. Thereby, the 2nd target air volume calculating part 31b acquires the measured value of the inflow flow rate _{Qin_1} (t) of the sewage (treated water) to the series 1 in the time t (step S46).
In step S47, sewage (treated water) flowing into the series 2 aerobic tank (reaction tank) 4-2 at time t, measured by the flow meter 11-2 installed in the series 2 inflow pipe 14-2. The measured value of the inflow flow rate Q in — ₂ (t) is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₂ (t) of the sewage (treated water) flowing into the series 2 aerobic tank (reaction tank) 4-2 at the time t taken in the internal bus Is transferred to the second target air volume calculation unit 31b. Thereby, the 2nd target air volume calculating part 31b acquires the measured value of the inflow flow rate _{Qin_2} (t) of the sewage (treated water) to the series 2 in the time t.

In step S48, the second target air volume calculating unit 31b performs the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 at the time t calculated in step S45. Target air volume QB _{2_DO} (t) to series 2 such that the dissolved oxygen concentration (DO concentration) in the inside becomes the same, the inflow flow rate of sewage (treated water) to series 1 at time t acquired in step S46 _{Based on} the measured value of Q in — ₁ (t) and the measured value of the inflow flow rate Q in — ₂ (t) of sewage (treated water) to the series 2 at time t acquired in step S47, the aerobic tank of series 2 (Reaction tank) Calculate the target air volume (after correction) to 4-2. Here, the target air volume (after correction) to the series 2 aerobic tank (reaction tank) 4-2 is calculated by the second target air volume calculating unit 31b executing the above-described equation (13). As a result, the target air volume for series 2 calculated in step S45 is corrected based on the difference in the inflow flow rate of sewage (treated water) flowing into series 1 and series 2, and the corrected value becomes series 2. Obtained as the target air volume (after correction).
In step S49, the second target air volume calculation unit 31b stores the calculated target air volume to the aerobic tank (reaction tank) 4-2 in the series 2 in the storage unit 35 via the internal bus 38. Store in the area. In place of step S49, the calculated target air volume to the aerobic tank (reaction tank) 4-2 of the series 2 may be transferred to the air volume valve opening calculator 33 described later via the internal bus 38. good.
Moreover, you may comprise so that step S41 and step S42 and step S46 and step S47 may be performed in parallel, respectively.
(Airflow valve opening calculator)
FIG. 10 is a process flow diagram of the air flow valve opening calculation unit 33 constituting the air flow control unit 3a.
As shown in FIG. 10, the air flow valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35, a series 1 aerobic tank (reaction tank) at time t. The target air volume QB _{1_set} (t) to 4-1 is read (step S51). Here, the target air volume QB _{1_set} (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t stored in the storage unit 35 is calculated by the first target air volume calculating unit 31a. The target air volume (FIG. 8).
In step S52, the air volume measurement value QB ₁ (indicated in the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the air volume meter 13-1 installed in the series 1 aeration pipe 18-1. t), that is, the air volume measurement value at the time t flowing through the series 1 aeration pipe 18-1 is taken into the measurement value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the air volume measurement value QB ₁ (t) to the aerobic tank (reaction tank) 4-1 of the series 1 at the time t taken into the air volume opening degree calculation unit 33 via the internal bus 38. Forward. As a result, the air volume opening calculation unit 33 acquires the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t.

In step S53, the air volume valve opening calculator 33 calculates the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t obtained in step S52, and step S51. The difference e ₁ (t) from the target air volume QB _{1 — set} (t) to the aerobic tank (reaction tank) 4-1 of the series 1 obtained in _step ( ₁ ) is calculated. Here, the difference e ₁ (t) is calculated by the above-described equation (5) being executed by the air flow valve opening degree calculation unit 33.
In step S54, the air volume valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35. The series 2 aerobic tank (reaction tank) 4-2 at time t is stored. The target air volume QB 2 — _set (t) is read out. Where it is stored in the storage unit 35, aerobic tank sequence 2 at time t target airflow _{QB 2_Set} to (reaction tank) 4-2 (t) is calculated by the second target air amount calculation unit 31b of the above The corrected target air volume (FIG. 9).
In step S55, the air flow measurement value QB ₂ (measured by the air flow meter 13-2 installed in the system 2 aeration pipe 18-2 to the system 2 aerobic tank (reaction tank) 4-2 at time t ( t), that is, the air volume measurement value at the time t flowing through the series 2 aeration pipe 18-2 is taken into the measurement value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measurement value acquisition unit 34 sends the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at the time t taken to the air volume opening calculation unit 33 via the internal bus 38. Forward. As a result, the air volume opening calculation unit 33 acquires the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t.

In step S56, the air volume valve opening calculator 33 calculates the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t acquired in step S55, and step S54. The difference e ₁ ′ (t) from the target air volume QB 2 — _set (t) to the aerobic tank (reaction tank) 4-2 in the series 2 at time t obtained in (5) is calculated. Here, the difference e ₁ ′ (t) is obtained by replacing QB ₁ (t) with QB ₂ (t) and QB _{1_set} (t) with QB _{2_set} (t) in the above equation (5), and the air flow valve opening degree. It is calculated by the calculation unit 33 executing.
In step S57, the air volume valve opening calculator 33 calculates the opening degree measured value VO ₁ (t) at the time t of the air volume valve 8-1 installed in the series 1 aeration pipe 18-1, and the series 2 aeration pipe. The opening measurement value VO ₂ (t) at the time t of the air flow valve 8-2 installed in 18-2 is taken in via the input I / F 36, the measurement value acquisition unit 34, and the internal bus 38.

At step S58, the opening degree measurement value _VO 1 of Kazeryouben 8-1 series 1 taken at step S57 (t), opening the measurement value _VO 2 of Kazeryouben 8-2 series 2 (t), step Based on the difference e ₁ (t) obtained in S53 and the difference e ₁ ′ (t) obtained in step S56, the air volume valve opening calculator 33 opens the series 1 air volume valves 8-1. And the opening degree of the air volume valve 8-2 of the series 2 are calculated. Here, the opening degree of the series 1 air volume valve 8-1 and the opening degree of the series 2 air volume valve 8-2 are changed by replacing e ₂ (t) with e ₁ ′ (t) in the above equation (4). It is calculated by the air volume valve opening calculation unit 33 executing.
In step S59, the air volume valve opening calculator 33 uses the opening of the series 1 air volume valve 8-1 and the opening of the series 2 air volume valve 8-2 calculated in step S58 as command values, respectively. The air is output to the series 1 air volume valve 8-1 and the series 2 air volume valve 8-2 via the bus 38 and the output I / F 37.

As described above, a water quality meter (for example, an ammonia meter) is operated by operating the first target air volume calculating unit 31a, the second target air volume calculating unit 31b, and the air volume valve opening degree calculating unit 33 that constitute the air volume control unit 3a. Based on the measured value of the dissolved oxygen concentration (DO concentration) of the series 1 performing the used air volume control, the target air volume to the other series 2 where no water quality meter is installed is calculated. Multiply the calculated target air volume for series 2 by a coefficient that corrects the difference in the inflow rate of sewage (treated water) flowing into series 1 where the water quality meter is installed and other series 2 where the water quality meter is not installed. Thus, the target air volume for the corrected series 2 is obtained. Based on the corrected target air volume for series 2, the opening degree of the air volume valve 8-1 for adjusting the aeration air volume for series 1 and the air volume valve 8-2 for adjusting the aeration air volume for series 2 is controlled. Thus, it is possible to realize appropriate air volume control to the other series 2 in which no water quality meter is installed.

In this embodiment, the dissolved oxygen concentration (DO concentration) in the series 1 aerobic tank (reaction tank) 4-1 and in the series 2 aerobic tank (reaction tank) 4-2 is equal. Although the target air volume to is calculated using Expression (11), the present invention is not limited to this. For example, the dissolved oxygen concentration (DO concentration) in the series 1 aerobic tank (reaction tank) 4-1 is multiplied by or added with a correction coefficient, and the series 2 aerobic tank (reaction tank). A configuration may be adopted in which the target air volume for series 2 is calculated so that the dissolved oxygen concentration (DO concentration) in 4-2 becomes equal.

In this embodiment, the dissolved oxygen concentration (DO concentration) in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 is equal. The flow rate of the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1 and the aerobic tank (reaction tank) 4-2 of the series 2 with respect to the target air volume to The target air volume to the corrected series 2 is obtained and set by multiplying the function related to the flow rate ratio of the inflow flow rate of sewage (treated water), but is not limited thereto. The flow rate of sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1 and the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-2 of the series 2 Other functions related to the inflow rate may be used. For example, the inflow rate of sewage (treated water) flowing into the series 1 aerobic tank (reaction tank) 4-1, and the series 2 aerobic tank (reaction tank) 4 -2 may be multiplied by a function related to the difference in the inflow rate of the sewage (treated water) flowing into -2. Furthermore, the target air volume to the series 2 such that the dissolved oxygen concentration (DO concentration) in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2 becomes equal. In contrast, the flow rate of the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1 and the sewage (treated) that flows into the aerobic tank (reaction tank) 4-2 of the series 2 The target air volume to the corrected series 2 may be obtained and set by adding a function related to the inflow flow rate of water.
In the present embodiment, the flow rate of the sewage (treated water) flowing into the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) in the above equation (13). ) The target air volume to the corrected series 2 was obtained and set using the inflow flow rate of sewage (treated water) flowing into 4-2, but the return sludge flow rate and / or the circulating flow rate of the activated sludge mixed liquid was set. The flow rate of sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1, respectively, and the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-2 of the series 2 May be added to the inflow flow rate.

According to the present embodiment, each series is corrected by correcting the setting of the aeration air volume in other series based on the DO concentration in the representative series where the water quality meter is installed based on the inflow flow rate of the water to be treated to each series. Therefore, it is possible to realize a water treatment system that can optimally control the amount of a water to be treated or the amount of aeration air.
Furthermore, specifically, based on the measured value of the dissolved oxygen concentration (DO concentration) of the series in which the air volume control using a water quality meter (for example, an ammonia meter) is executed, the flow to other series where the water quality meter is not installed. Calculate the target air volume. Multiplying the calculated target airflow to another series by a coefficient that corrects the difference in the inflow rate of sewage (treated water) that flows into the series where the water quality meter is installed and the other series where the water quality meter is not installed Thus, the target air volume to the other series 2 after correction is obtained. An air volume valve 8 that adjusts the aeration air volume to the series where the water quality meter is installed and an air volume valve that adjusts the aeration air volume to other series where the water quality meter is not installed based on the corrected target air volume to the other series By controlling the opening degree, it is possible to realize appropriate air volume control to other systems where no water quality meter is installed.

FIG. 11 shows a process flow diagram of the second target air volume calculation unit constituting the air volume control unit of the third embodiment according to another embodiment of the present invention, and FIG. 12 shows the air volume control unit of the third embodiment. The processing flow figure of an airflow valve opening calculating part is shown. In addition, the structure of the water treatment apparatus which concerns on a present Example is the same as the structure of FIG. 6 shown in the above-mentioned Example 2. FIG. Moreover, the structure of the air volume control part of a present Example is the same as the functional block diagram of FIG. 7 shown in the above-mentioned Example 2. FIG. In the present embodiment, in addition to the target air volume after correction to the series 2 shown in the second embodiment, the target air volume to the series 2 is obtained based on the target air volume to the series 1 shown in the first embodiment or the second embodiment. The embodiment is configured such that the target air volume for the series 2 thus obtained is compared with the corrected target air volume for the series 2, and any one of the target air volumes that are large is used as the target air volume for the series 2. 1 and different from Example 2. Below, the description which overlaps with Example 1 or Example 2 is abbreviate | omitted.

In the present embodiment, the air volume control unit 3a (FIG. 7) performs the aerobic tank (reaction tank) 4 of the series 2 based on the target air volume to the aerobic tank (reaction tank) 4-1 of the series 1 shown in FIG. The target air volume to -2 is also calculated. The amount of air necessary for water treatment is affected by the inflow rate of sewage to be treated and the performance of the diffuser. Therefore, in order to make the processing performance similar to that of the system 1 in the system 2, it is desirable to correct the difference in the flow rate of the sewage (treated water) and the performance of the air diffuser and set the target air volume. Formula (14) shows a target air volume setting formula for series 2 based on the target air volume for series 1. *

Here, QB 2 — _air (t) [m ³ / min]: Series 2 aerobic tank (reaction tank) 4-based on the target air volume to the series 1 aerobic tank (reaction tank) 4-1 at time t 4 _{Qb 1_set} (t) [m ³ / min]: target air flow set value to the aerobic tank (reaction tank) 4-1 of series 1 at time t, Q in — _i (t ) [M ³ / min]: Inflow flow rate of sewage to the aerobic tank (reaction tank) of series i at time t (i = 1 or 2), δ [−]: related to air diffusion efficiency Coefficient, q [−]: Coefficient.

Next, the air volume control unit 3a corrects the target air volume to the series 2 based on the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) 4-1 of the series 1 in the above equation (13), That is, the target air volume (after correction) to the series 2 aerobic tank (reaction tank) 4-2 obtained in step 48 of FIG. 9 and the series 1 aerobic tank (reaction tank) in equation (14). Compare the target air volume (air volume calculation value) to the aerobic tank (reaction tank) 4-2 in the series 2 based on the target air volume to the 4-1 and select a larger target air volume as the target air volume to the series 2 Set.
Further, the air volume control unit 3a determines the opening degree of the air volume valve 8-1 installed in the series 1 aeration pipe 18-1 and the air volume valve 8-2 installed in the series 2 aeration pipe 18-2. It controls based on Formula (4) and Formula (5). The opening degree of the air volume valve 8-1 is controlled so that the air volume to the series 1 approaches the set value of the target air volume to the series 1 set by the air volume control unit 3a. Further, the opening degree of the air volume valve 8-2 is controlled so that the air volume to the series 2 approaches the set value of the target air volume to the series 2 set by the air volume control unit 3a.

Thus, in this example, the method based on the dissolved oxygen concentration (DO concentration) in the aerobic tank (reaction tank) of the series that performs air volume control using a water quality meter (for example, an ammonia meter), The target air volume is calculated for the other series where the water quality meter is not installed by the two methods based on the target air volume for the aerobic tank (reaction tank) where the water quality meter is installed. By selecting a safer target air volume from the viewpoint of processing performance among the target air volumes, the quality of the treated water can be kept good.

Below, the detail of the process by the 1st target air volume calculating part 31a, the 2nd target air volume calculating part 31b, and the air volume valve opening degree calculating part 33 which comprises the air volume control part 3a is demonstrated.
(First target air volume calculation unit)
Similarly to the second embodiment, the first target air volume calculation unit 31a executes steps S11 to S15 shown in FIG. 8 and calculates the target air volume to the aerobic tank (reaction tank) 4-1 of the series 1.
(Second target air volume calculation unit)
FIG. 11 is a process flow diagram of the second target air volume calculation unit 31b constituting the air volume control unit 3a.
As shown in FIG. 11, the second target air volume calculation unit 31 b accesses the storage unit 35 via the internal bus 38 and is stored in the storage unit 35, the series 1 aerobic tank (reaction tank) at time t. The target air volume setting value QB _{1 —} set (t) to 4-1 is read (step S61).
Subsequently, the sewage (treated water) flowing into the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the flow meter 11-1 installed in the series 1 inflow pipe 14-1. The measured value of the inflow flow rate Q in — ₁ (t) is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₁ (t) of the sewage (treated water) flowing into the aerobic tank (reaction tank) 4-1 of the series 1 at the time t taken, Is transferred to the second target air volume calculation unit 31b. Thereby, the 2nd target air volume calculating part 31b acquires the measured value of the inflow flow rate _{Qin_1} (t) of the sewage (treated water) to the series 1 in the time t (step S62).

In step S63, sewage (treated water) flowing into the series 2 aerobic tank (reaction tank) 4-2 at time t, measured by the flow meter 11-2 installed in the series 2 inflow pipe 14-2. The measured value of the inflow flow rate Q in — ₂ (t) is taken into the measured value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 uses the measured value of the inflow flow rate Q in — ₂ (t) of the sewage (treated water) flowing into the series 2 aerobic tank (reaction tank) 4-2 at the time t taken in the internal bus Is transferred to the second target air volume calculation unit 31b. Thereby, the 2nd target air volume calculating part 31b acquires the measured value of the inflow flow rate _{Qin_2} (t) of the sewage (treated water) to the series 2 in the time t.

In step S64, the second target air volume calculation unit 31b sets the target air volume setting value QB _{1_set} (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t acquired in step S61, step S62. The measured value of the inflow flow rate Q in — ₁ (t) of the sewage (treated water) to the series 1 at time t acquired at time t and the sewage (treated) to the series 2 at time t obtained in step S63 Based on the measured value of the inflow flow rate Q in — ₂ (t) of water, the target air volume QB 2 — _air (t) to the series 2 aerobic tank (reaction tank) 4-2 is calculated. Here, the target air volume QB _{2_air} (t) to the series 2 aerobic tank (reaction tank) 4-2 is calculated by the second target air volume calculating unit 31b executing the above-described equation (14).
In step S65, the second target air volume calculation unit 31b sends the calculated target air volume (air volume calculation value) QB _{2_air} (t) to the aerobic tank (reaction tank) 4-2 of the series 2 via the internal bus 38. The data is stored in a predetermined storage area of the storage unit 35. In place of step S65, the calculated target air volume (air volume calculation value) QB _{2 —} air (t) to the aerobic tank (reaction tank) 4-2 of the series 2 is _opened via the internal bus 38 to be described later. It is good also as a structure transferred to the degree calculating part 33. FIG. Moreover, you may comprise so that it may perform in step S62 and step S63 in parallel.

Similarly to the second embodiment, the second target air volume calculation unit 31b executes Steps S41 to S49 shown in FIG. 9 and supplies the calculated series 2 to the aerobic tank (reaction tank) 4-2. The corrected target air volume is stored in a predetermined storage area of the storage unit 35 via the internal bus 38.
(Airflow valve opening calculator)
FIG. 12 is a process flow diagram of the air flow valve opening calculation unit 33 constituting the air flow control unit 3a.
As shown in FIG. 12, the air flow valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35, the series 1 aerobic tank (reaction tank) at time t. The target air volume QB _{1_set} (t) to 4-1 is read (step S71). Here, the target air volume QB _{1_set} (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t stored in the storage unit 35 is calculated by the first target air volume calculating unit 31a. The target air volume (FIG. 8).
In step S72, the air volume measurement value QB ₁ (indicated in the series 1 aerobic tank (reaction tank) 4-1 at time t, measured by the air volume meter 13-1 installed in the series 1 air diffusion pipe 18-1. t), that is, the air volume measurement value at the time t flowing through the series 1 aeration pipe 18-1 is taken into the measurement value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measured value acquisition unit 34 sends the air volume measurement value QB ₁ (t) to the aerobic tank (reaction tank) 4-1 of the series 1 at the time t taken into the air volume opening degree calculation unit 33 via the internal bus 38. Forward. As a result, the air volume opening calculation unit 33 acquires the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t.

In step S73, the air volume valve opening calculator 33 calculates the air volume measurement value QB ₁ (t) to the series 1 aerobic tank (reaction tank) 4-1 at time t obtained in step S72, and step S71. The difference e ₁ (t) from the target air volume QB _{1 — set} (t) to the aerobic tank (reaction tank) 4-1 of the series 1 obtained in _step ( ₁ ) is calculated. Here, the difference e ₁ (t) is calculated by the above-described equation (5) being executed by the air flow valve opening degree calculation unit 33.
In step S74, the air volume valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35, the series 2 aerobic tank (reaction tank) 4-2 at time t. The target air volume QB _{2_set} (t) after correction to is read. Here, the corrected target air volume QB _{2_set} (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t stored in the storage unit 35 is the above-described second target air volume calculating unit 31b. Is the corrected target air volume (FIG. 9).
In step S75, the air volume valve opening calculation unit 33 accesses the storage unit 35 via the internal bus 38, and is stored in the storage unit 35, the series 2 aerobic tank (reaction tank) 4-2 at time t. The target air volume (air volume calculation value) QB _{2 —} air (t) is read. Here, the target air volume (air volume calculation value) QB _{2_air} (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t stored in the storage unit 35 is the second target air volume calculation described above. The part 31b is the calculated target air volume (air volume calculation value) (FIG. 11).
In step S76, the air volume valve opening calculator 33 calculates the corrected target air volume QB _{2_set} (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t read in step S74. Then, the target air volume (air volume calculation value) QB _{2 —} air (t) to the aerobic tank (reaction tank) 4-2 in the series 2 at time t read in step S75 is compared. As a result of the comparison, one of the corrected target air volume QB 2 — _set (t) and target air volume (air volume calculation value) QB _{2 —} air (t) that has a larger air volume is selected.

In step S77, the air flow measurement value QB ₂ (to the series 2 aerobic tank (reaction tank) 4-2 at time t, measured by the air flow meter 13-2 installed in the series 2 aeration pipe 18-2 ( t), that is, the air volume measurement value at the time t flowing through the series 2 aeration pipe 18-2 is taken into the measurement value acquisition unit 34 via the input I / F 36 and the internal bus 38. The measurement value acquisition unit 34 sends the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at the time t taken to the air volume opening calculation unit 33 via the internal bus 38. Forward. As a result, the air volume opening calculation unit 33 acquires the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t.

In step S78, the air volume valve opening calculator 33 calculates the air volume measurement value QB ₂ (t) to the series 2 aerobic tank (reaction tank) 4-2 at time t acquired in step S77, and step S76. The difference e ₁ ′ (t) between the target air volume QB 2 — _set (t) after correction to the series 2 selected in step 1 or the target air volume (air volume calculation value) QB _{2 —} air (t) to the series 2 is calculated. Here, the difference e ₁ ′ (t) is equal to QB ₁ (t) in QB ₂ (t) and QB _{1_set} (t) in QB _{2_set} (t) or QB _{2_air} (t) in the above equation (5). It is calculated by the replacement and the air volume valve opening calculation unit 33 executing.

In step S79, the air volume valve opening calculator 33 calculates the opening degree measured value VO ₁ (t) at the time t of the air volume valve 8-1 installed in the series 1 aeration pipe 18-1, and the series 2 aeration pipe. The opening measurement value VO ₂ (t) at the time t of the air flow valve 8-2 installed in 18-2 is taken in via the input I / F 36, the measurement value acquisition unit 34, and the internal bus 38.
In step S80, the opening degree measurement value _VO 1 of Kazeryouben 8-1 series 1 taken at step S79 (t), opening the measurement value _VO 2 of Kazeryouben 8-2 series 2 (t), step Based on the difference e ₁ (t) obtained in S73 and the difference e ₁ ′ (t) obtained in step S78, the air flow valve opening calculation unit 33 opens the air flow valve 8-1 in the series 1. And the opening degree of the air volume valve 8-2 of the series 2 are calculated. Here, the opening degree of the series 1 air volume valve 8-1 and the opening degree of the series 2 air volume valve 8-2 are changed by replacing e ₂ (t) with e ₁ ′ (t) in the above equation (4). It is calculated by the air volume valve opening calculation unit 33 executing.
In step S81, the air volume valve opening calculator 33 uses the opening of the series 1 air volume valve 8-1 and the opening of the series 2 air volume valve 8-2 calculated in step S80 as command values, respectively. The air is output to the series 1 air volume valve 8-1 and the series 2 air volume valve 8-2 via the bus 38 and the output I / F 37.

As described above, a water quality meter (for example, an ammonia meter) is operated by operating the first target air volume calculating unit 31a, the second target air volume calculating unit 31b, and the air volume valve opening degree calculating unit 33 that constitute the air volume control unit 3a. A method based on the measured value of the dissolved oxygen concentration (DO concentration) of the series 1 executing the air volume control used, and a method based on the target air volume to the aerobic tank (reaction tank) of the series 1 where the water quality meter is installed Using the two methods, the target air volume for the other series 2 where the water quality meter is not installed is obtained, and among the obtained target air volumes for the other series 2, the target air volume on the safer side is determined from the viewpoint of processing performance. By selecting, the quality of treated water can be kept good.

In the present embodiment, in Formula (14), in consideration of the difference in the inflow flow rate and aeration efficiency into the sewage (treated water) aerobic tank (reaction tank) for each series, the target for the series 2 Although the air volume is set, it is not necessarily limited to this. For example, an aeration liquid suspension concentration meter (MLSS meter) as a microbial concentration meter is installed in the series 1 aerobic tank (reaction tank) 4-1 and the series 2 aerobic tank (reaction tank) 4-2. The target air volume for series 2 may be set by a setting formula that takes into account the difference in MLSS concentration.
In this embodiment, the coefficient related to the air diffusion efficiency is a fixed value, but a value calculated using the relationship between the air volume and the dissolved oxygen concentration (DO concentration) may be used.

According to the present embodiment, each series is corrected by correcting the setting of the aeration air volume in other series based on the DO concentration in the representative series where the water quality meter is installed based on the inflow flow rate of the water to be treated to each series. Therefore, it is possible to realize a water treatment system that can optimally control the amount of a water to be treated or the amount of aeration air.
Furthermore, specifically, a method based on a measured value of dissolved oxygen concentration (DO concentration) in a series in which air volume control using a water quality meter (for example, an ammonia meter) is executed, and a series in which the water quality meter is installed Using the two methods based on the target airflow to the aerobic tank (reaction tank), obtain the target airflow to the other series where the water quality meter is not installed, and out of the calculated target airflow to the other series By selecting a safer target air volume from the viewpoint of processing performance, it is possible to maintain good quality of the treated water.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 1 ... Water treatment system 2 ...

Water treatment apparatus

3, 3a ... Air volume control part 4-1, 4-2 ... Aerobic tank (reaction tank)
5-1, 5-2 ... Final sedimentation tanks 6-1, 6-2 ... Air diffuser 7 ... Blowers 8-1, 8-2 ... Air flow valves 9-1, 9-2 ... Return pump 10 ... Ammonia meters 11-1, 11-2 ... Flow meters 12-1, 12-2 ... Dissolved oxygen concentration meter (DO meter)
13-1, 13-2 ... Air flow meter 14 ... Inflow piping 14-1 ... Series 1 inflow piping 14-2 ... Series 2 inflow piping 15-1 ... Series 1 outflow piping 15- 2 ... Series 2 outflow piping 16-1, 16-2 ... Activated sludge 17-1 ... Series 1 return sludge piping 17-2 ... Series 2 return sludge piping 18-1 ... Series 1 Aeration pipe 18-2... Series 2 aeration pipe 31... Target air volume calculation unit 31a... First target air volume calculation unit (series 1)
31b ... second target air volume calculation unit (series 2)
32 ... DO concentration target value calculation unit 33 ... Air flow valve opening calculation unit 34 ... Measurement value acquisition unit 35 ... Storage unit 36 ... Input I / F
37 ... Output I / F
38 ... Internal bus

Claims

A plurality of systems having at least a reaction tank including an aerobic tank and a diffuser provided in the aerobic tank; and a dissolved oxygen concentration for measuring a dissolved oxygen concentration of the aerobic tank installed in all of the plurality of systems A flow meter for measuring the flow rate of water to be treated flowing into the reaction tanks of each series or a flow rate estimation unit for estimating the flow rate of the treated water, and the water quality installed in the aerobic tank of one series A water treatment device having a meter and a blower for supplying air to the air diffuser of each series;
An air volume control unit for controlling the air volume of air supplied from the blower to each series of air diffusers,
The air volume control unit
While controlling the air volume to one series where the water quality meter is installed based on the measurement value of the water quality meter,
Of the one series and the other series, at least one of the dissolved oxygen concentration measurement values, the inflow flow rate of the water to be treated of one series where the water quality meter of the one series is installed, and the other series A water treatment system characterized by controlling an air volume to at least one of the other series based on an inflow rate of water to be treated of at least one series.
The water treatment system according to claim 1,
The air volume control unit
A target air volume calculating unit for obtaining a target air volume to the one series based on the measurement value of the water quality meter;
Based on the measured dissolved oxygen concentration value of the one series and the inflow rate of the treated water, and the inflow rate of the treated water of at least one series of the other series, at least one series of the other series A dissolved oxygen concentration target value calculation unit for obtaining a dissolved oxygen concentration target value;
A water treatment characterized by controlling the air volume to at least one of the other series based on the dissolved oxygen concentration target value and the dissolved oxygen concentration measurement value of at least one of the other series system.
The water treatment system according to claim 1,
The air volume control unit
A first target air volume calculating unit for obtaining a target air volume for the one series based on the measurement value of the water quality meter;
Finding the target air volume to at least one of the other series in which the dissolved oxygen concentration measurement value of at least one of the one series and the other series is the same, and obtaining the other series Based on the target air volume to at least one of the series and the inflow flow rate of the treated water of at least one of the one series and the other series, the target to at least one of the other series A second target air volume calculation unit for correcting the air volume,
The water treatment system characterized by controlling the air volume to at least one of the other systems based on the target air volume corrected by the second target air volume computing unit.
The water treatment system according to claim 1,
The air volume control unit
A first target air volume calculating unit for obtaining a target air volume for the one series based on the measurement value of the water quality meter;
The dissolved oxygen concentration measurement value of the one series and the inflow flow rate of the water to be treated and the dissolved oxygen concentration target value of at least one series of the other series are obtained, and at least one of the obtained other series is obtained. Based on the dissolved oxygen concentration target value of the series and the dissolved oxygen concentration measurement value, and obtaining a target air volume to at least one of the other series,
At least one of the other series based on the target air volume to the one series by the first target air volume calculating unit and the inflow flow rate of the water to be treated of at least one of the one series and the other series. A second target air volume calculation unit for obtaining a target air volume calculation value for one series,
A water treatment system that controls the air volume of at least one of the other series based on one of the target air volume to at least one of the other series and the target air volume calculation value. .
The water treatment system according to claim 1,
The air volume control unit
A first target air volume calculating unit for obtaining a target air volume for the one series based on the measurement value of the water quality meter;
Finding the target air volume to at least one of the other series in which the dissolved oxygen concentration measurement value of at least one of the one series and the other series is the same, and obtaining the other series After correction to at least one of the other series based on the target air volume to at least one of the series and the inflow flow rate of the treated water of at least one of the one series and the other series While calculating the target air volume of
The target air volume to the other series based on the target air volume to the one series by the first target air volume calculating unit and the inflow flow rate of the treated water of at least one of the one series and the other series A second target air volume calculating unit for calculating a calculated value,
A water treatment system, wherein the air volume of at least one of the other series is controlled based on one of the corrected target air volume and the target air volume calculation value.
The water treatment system according to claim 2,
The water treatment device includes an air flow meter installed in an air diffuser pipe connecting the air diffuser of the one series and the blower,
The air volume control unit
The difference between the target air volume to the one series by the target air volume calculator and the air volume measurement value by the anemometer, and the dissolved oxygen concentration of at least one of the other series by the dissolved oxygen concentration target value calculator A water treatment system that controls an air volume to at least one of the other series based on a difference between a target value and a measured value of the dissolved oxygen concentration.
The water treatment system according to claim 3,
The water treatment apparatus includes: a first air flow meter installed in a first aeration pipe connecting the one series of air diffusers and the blower; and at least one series of air diffusers of the other series And a second air flow meter installed in a second aeration pipe connecting the blower,
The air volume control unit
To at least one of the difference between the target air volume to the one series by the first target air volume calculation unit and the air volume measurement value by the first air flow meter and the other series by the second target air volume calculation unit A water treatment system that controls the air volume to at least one of the other series based on the difference between the corrected target air quantity and the air quantity measurement value obtained by the second anemometer.
The water treatment system according to claim 4,
The water treatment apparatus includes: a first air flow meter installed in a first aeration pipe connecting the one series of air diffusers and the blower; and at least one series of air diffusers of the other series And a second air flow meter installed in a second aeration pipe connecting the blower,
The air volume control unit
To at least one of the difference between the target air volume to the one series by the first target air volume calculation unit and the air volume measurement value by the first air flow meter and the other series by the second target air volume calculation unit A water treatment system that controls the air volume to at least one of the other series based on the target air volume or the difference between the target air volume calculation value and the air volume measurement value obtained by the second anemometer .
The water treatment system according to claim 5,
The water treatment apparatus includes: a first air flow meter installed in a first aeration pipe connecting the one series of air diffusers and the blower; and at least one series of air diffusers of the other series And a second air flow meter installed in a second aeration pipe connecting the blower,
The air volume control unit
The difference between the target air volume to the one series by the first target air volume calculator and the air volume measurement value by the first air volume meter, the corrected target air volume by the second target air volume calculator, or the target air volume calculation A water treatment system for controlling an air volume to at least one of the other series based on a difference between a value and an air quantity measured by the second anemometer.
In the water treatment system according to any one of claims 6 to 9,
The water quality meter is any one of ammonia nitrogen concentration, nitrate nitrogen concentration, total nitrogen concentration, phosphoric acid phosphorus concentration, total phosphorus concentration, biochemical oxygen demand, chemical oxygen demand, and total organic carbon. Water treatment system characterized by being a measuring instrument that measures water.
In the water treatment system according to any one of claims 6 to 9,
Installed in the reaction tanks of all series, equipped with an activated sludge suspended solids concentration meter that measures the activated sludge suspended solids concentration in the reaction tank,
The air volume control unit
While controlling the air volume to one series where the water quality meter is installed based on the measurement value of the water quality meter,
Measurement values of the water quality meter, all series of dissolved oxygen concentration measurement values and activated sludge suspended matter concentration measurement values, the inflow flow rate of the treated water of the one series, and the inflow of treated water of the other series A water treatment system that controls an air volume to the other series based on a flow rate.