JP7103598B2 - Water treatment control device and water treatment system - Google Patents

Description

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

At sewage treatment plants, sewage is generally treated according to the following procedure. First, solids in the sewage are removed in the sand basin and the first settling basin. The solid content separated in the first settling basin is transferred to sludge treatment as the first settling basin sludge. First, the sedimentation basin effluent removes organic matter, nitrogen, and phosphorus by the action of microorganisms (activated sludge) in the reaction tank. After that, the activated sludge is settled and separated in the final settling basin, and the supernatant water is discharged to the public water area as effluent water. The activated sludge that has settled and separated in the final settling basin is returned to the reaction tank and used again for sewage treatment.
In a combined sewage system that consolidates sewage and rainwater into a sewage treatment plant with the same pipe, in general, sewage that exceeds the maximum planned sewage amount is simply treated by first removing solids in the sedimentation basin and then disinfecting it. After that, it is released into public water areas.

In the simple treatment, the conventional biological treatment is not performed, and the reduction of the environmental load on the discharge destination is an issue. Therefore, for example, Non-Patent Document 1 has been proposed as a method for increasing the amount of biological treatment and reducing the simple treatment discharge flow rate, and it has been confirmed that the discharge pollution load can be reduced while maintaining good treated water quality. There is.
Further, for example, Patent Document 1 describes a sewage treatment system that can correctly determine whether or not direct discharge can be performed by using an existing system and automatically performs operations such as direct discharge. The technology to be used is proposed. In Patent Document 1, the inflow increase status calculation unit that inputs the total pump water pumping amount and the rainfall amount and outputs the increase status of the inflow amount to the dilution status calculation unit of the inflow water by executing fuzzy inference, and the inflow increase. Input the output of the status calculation unit, the dissolved oxygen concentration value, and the air flow rate of the reaction tank to determine the dilution status of the inflow water. It has an inflow water treatment calculation unit composed of a judgment / operation command unit that outputs commands such as start / stop of the discharge pump, but the water treatment system is disclosed.

JP-A-2002-136987

Takahiro Yamamoto et al., Improvement of confluence sewerage using existing facilities in Osaka City, Journal of Environmental System Measurement and Control Society, Vol. 10, No. 2 (2006)

However, in the water treatment system described in Non-Patent Document 1 and the sewage treatment system described in Patent Document 1, the amount that can be accepted into the biological reaction tank is limited to the solid-liquid separation capacity in the final settling basin. In the final sedimentation basin, the sludge sedimentation time becomes shorter as the inflow water volume increases, and the sludge interface rises. Therefore, the inflow water volume must be limited depending on the sludge sedimentation situation. Therefore, if the amount of inflow water is excessively increased prior to the peak of the sewage concentration, for example, the high-concentration sewage may not be sufficiently treated.
Therefore, the present invention provides a water treatment control device capable of ensuring the maximum amount of biological treatment within a range in which sludge outflow can be prevented even when the inflow flow rate and inflow water quality of sewage (water to be treated) fluctuate. Provide a water treatment system.

In order to solve the above problems, the water treatment control device according to the present invention activates at least a reaction tank in which a part or all of the sewage to be treated is treated with active sludge and the outflow water flowing out from the reaction tank. A water treatment control device that controls a water treatment device having a final settling pond that is settled and separated into sludge and treated water. A processable amount calculation unit that calculates an upper limit value of the inflow water amount into the tank and a treatment amount control unit that controls the inflow water amount into the reaction tank are provided, and the treatment amount control unit predicts the inflow water amount / water quality. The amount of water flowing into the reaction tank is controlled based on the output value of the unit and the output value of the processable amount calculation unit, and the processable amount calculation unit is in the reaction tank measured by a sludge concentration meter. Based on the measured value of the active sludge concentration, the upper limit of the inflow water amount into the reaction tank is obtained, and the treatment amount control unit obtains the upper limit of the inflow water amount into the reaction tank and the inflow obtained by the treatable amount calculation unit. It is characterized in that the amount of inflow water into the reaction tank is calculated based on the output value of the water amount / water quality prediction unit .
Further, in the water treatment control device according to the present invention, at least a reaction tank in which a part or all of the sewage to be treated is treated with active sludge, and the effluent flowing out from the reaction tank is treated with active sludge and treated water. It is a water treatment control device that controls a water treatment device having a final settling pond that is settled and separated into a water treatment device. A processable amount calculation unit for calculating the upper limit value of the above and a treatment amount control unit for controlling the inflow water amount to the reaction tank are provided, and the treatment amount control unit has an output value of the inflow water amount / water quality prediction unit. , The amount of water flowing into the reaction tank is controlled based on the output value of the treatable amount calculation unit, and the treatable amount calculation unit measures the active sludge concentration in the reaction tank as measured by the sludge concentration meter. Based on the value and the measured value of the active sludge interface of the final settling pond measured by the sludge interface meter or the SS concentration or turbidity of the treated water by the final settling pond, the upper limit of the amount of inflow water into the reaction tank was obtained. The treatment amount control unit calculates the inflow water amount into the reaction tank based on the upper limit of the inflow water amount into the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. It is characterized by.

Further, in the water treatment system according to the present invention, at least a reaction tank in which a part or all of the sewage to be treated is treated with active sludge, and the effluent flowing out from the reaction tank is settled in the active sludge and the treated water. A water treatment device having a final sedimentation pond to be separated, an inflow water amount / water quality prediction unit that predicts the future flow rate and water quality of sewage, a treatable amount calculation unit that calculates an upper limit value of the inflow water amount into the reaction tank, and the like. A water treatment control device including a treatment amount control unit for controlling the amount of inflow water into the reaction tank is provided, and the treatment amount control unit includes an output value of the inflow water amount / water quality prediction unit and the processable amount. The amount of water flowing into the reaction tank is controlled based on the output value of the calculation unit, and the treatable amount calculation unit is based on the measured value of the active sludge concentration in the reaction tank measured by the sludge concentration meter. The upper limit of the inflow water amount to the reaction tank is obtained , and the treatment amount control unit is based on the upper limit of the inflow water amount to the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. , The feature is to calculate the amount of inflow water into the reaction tank .
Further, in the water treatment system according to the present invention, at least a reaction tank in which a part or all of the sewage to be treated is treated with active sludge, and the effluent flowing out from the reaction tank is settled in the active sludge and the treated water. A water treatment device having a final sedimentation pond to be separated, an inflow water amount / water quality prediction unit that predicts the future flow rate and water quality of sewage, a treatable amount calculation unit that calculates an upper limit value of the inflow water amount into the reaction tank, and the like. A water treatment control device including a treatment amount control unit for controlling the amount of inflow water into the reaction tank is provided, and the treatment amount control unit includes an output value of the inflow water amount / water quality prediction unit and the processable amount. The amount of water flowing into the reaction tank is controlled based on the output value of the calculation unit, and the treatable amount calculation unit controls the measured value of the active sludge concentration in the reaction tank measured by the sludge concentration meter and the sludge interface. Based on the measured value of the active sludge interface of the final settling pond measured by the meter or the SS concentration or turbidity of the treated water by the final settling pond, the upper limit of the inflow water amount to the reaction tank is obtained, and the treatment amount control unit It is characterized in that the amount of inflow water into the reaction tank is calculated based on the upper limit of the amount of inflow water into the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit.

According to the present invention, a water treatment control device capable of ensuring the maximum amount of biological treatment within a range in which sludge outflow can be prevented even when the inflow flow rate and inflow water quality of sewage (water to be treated) fluctuate. It becomes possible to provide a water treatment system.
Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

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 water treatment control device shown in FIG. It is a flow rate control flow chart of the amount of inflow water into an aerobic tank (reaction tank) by the water treatment control apparatus shown in FIG. It is a schematic overall block diagram of the water treatment system of Example 2 which concerns on another Example of this invention. It is a functional block diagram of the water treatment control device shown in FIG. It is a flow rate control flow chart of the amount of inflow water into an aerobic tank (reaction tank) by the water treatment control apparatus shown in FIG.

In the present specification, the description will be made on the assumption that the inflow flow rate and the inflow water quality of the sewage (water to be treated) fluctuate due to rainfall, but the present specification is not necessarily limited to this. Not limited to rainfall, for example, even in a water treatment apparatus having a final sedimentation basin in which the sedimentation separation performance due to gravity sedimentation is not efficient, the inflow flow rate and the inflow water quality of sewage (water to be treated) may fluctuate.
Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic overall configuration diagram of the water treatment system of Example 1 according to an embodiment of the present invention. In FIG. 1, the solid line shows the piping and the dotted line shows the signal line. The water treatment system 1 according to the present embodiment is a water treatment device 2 for removing sewage (treated water) such as domestic wastewater or industrial wastewater by using activated sludge in the standard activated sludge method, and water. A processing control device 3 is provided.

(Configuration of water treatment device 2)
As shown in FIG. 1, the water treatment apparatus 2 includes a first settling basin 4, an aerobic tank (reaction tank) 5, and a final settling basin 6 in this order from the inflow side of the sewage 100 to be treated. As shown in FIG. 1, the aerobic tank (reaction tank) 5 is provided in four stages or in series with four tanks. In the following, a case where four aerobic tanks (reaction tanks) 5 are provided in series is shown as an example, but the number of tanks is not limited to this and is appropriately set.

For example, sewage 100, which is water to be treated, flows into the first settling basin 4 from a sand basin (not shown), and the solid content contained in the sewage 100 is settled and separated in the first settling basin 4 by gravity sedimentation. A part of the supernatant water due to the sedimentation separation flows into the aerobic tank (reaction tank) 5 as the aerobic tank inflow water 101 through the movable weir 14. The remaining supernatant water is discharged as a simple treated effluent 103 through a process such as disinfection.
The first flow meter 10 installed in the flow path of the sewage 100 to the first settling basin 4 (installed on the upstream side of the first settling basin 4) measures the flow rate of the sewage 100 flowing into the first settling basin 4. do. The measured flow rate of the sewage 100 is output to the water treatment control device 3 described later via the signal line. Further, the UV total 11 installed in the flow path of the sewage 100 to the first settling basin 4 (installed on the upstream side of the first settling basin 4) is an organic substance of the sewage (treated water) 100 that first flows into the settling basin 4. Measure the concentration. The measured organic matter concentration of the sewage 100 is output to the water treatment control device 3 described later via the signal line. Further, although not shown, a rain gauge for measuring the amount of rainfall in the treatment area is installed, and the rainfall information such as the amount of rainfall measured by the rain gauge is output to the water treatment control device 3 described later via a signal line. It is desirable to have a configuration that does.

Further, in the aerobic tank (reaction tank) 5 on the most upstream side (first stage), the aerobic tank inflow water 101 that first flows in from the settling pond 4 via the movable weir 14 and the returned sludge 105 flow into the aerobic tank (reaction tank) 5 and are activated. Organic matter is oxidized by aerobic dependent vegetative bacteria in sludge. Further, an air diffuser 7 is installed in the aerobic tank (reaction tank) 5. A blower 8 is connected to the air diffuser 7 to supply air. The second flow meter 12 installed in the flow path of the aerobic tank (reaction tank) 5 from the first settling basin 4 measures the flow rate of the aerobic tank inflow water 101. The measured flow rate of the aerobic tank inflow water 101 is output to the water treatment control device 3 described later via the signal line. Further, a sludge concentration meter 13 is installed in the aerobic tank (reaction tank) 5 on the downstream side in the aerobic tank (reaction tank) 5, in other words, in the final stage aerobic tank (reaction tank) 5, and in the aerobic tank (reaction tank) 5. Measure the activated sludge concentration of. The measured activated sludge concentration in the aerobic tank (reaction tank) 5 is output to the water treatment control device 3 described later via the signal line.

The final sedimentation basin 6 is a facility for sedimentation and separation of the supernatant liquid and activated sludge by gravity sedimentation. The supernatant liquid after sedimentation separation is discharged to the outside of the system as treated water 104. Further, a part of the activated sludge 102 settled and separated is returned to the aerobic tank (reaction tank) 5 by the return pump 9 as the return sludge 105, and is again subjected to a series of biological treatments. Although not shown, the other part of the activated sludge 102 that has been settled and separated is transferred to sludge treatment as surplus sludge by a surplus sludge pump (not shown).

(Configuration of water treatment control device 3)
FIG. 2 is a functional block diagram of the water treatment control device 3 shown in FIG. As shown in FIG. 2, the water treatment control device 3 includes a rainfall information acquisition unit 20, an inflow water amount / water quality prediction unit 21, a treatable amount calculation unit 22, a treatment amount control unit 23, a measured value acquisition unit 24, and a sewage flow time. It includes a change database 25, a rainfall-inflow water amount correlation database 26, a sewage organic substance concentration time change database 27, a communication I / F28, an input I / F29 and an output I / F30, which are connected to each other via an internal bus 33. Has been done. Further, the input I / F 29 is connected to the input unit 31, and is input via the input unit 31. The upper limit of the flow rate of the aerobic tank inflow water 101 per unit time based on the facility conditions and the like, and the sludge in the final settling basin 6. Incorporate the upper limit of the interface. The output I / F 28 is connected to the display unit 32, and the display unit 32 displays desired information on the screen, for example, various set values or rainfall information in the processing area as needed. Although not shown, the water treatment control device 3 also has a function of controlling the blower 8 in order to control the amount of aerated air supplied to the aerobic tank (reaction tank) 5 via the air diffuser 7. There is. In this embodiment, the case where the water treatment control device 3 has the rainfall information acquisition unit 20 will be described as an example.

The sewage flow rate time change database 25 stores past actual data. For example, the flow rate of sewage 100 according to the time zone on a daily basis, or the flow rate of sewage 100 seasonally on a yearly basis, for example. The time changes of are stored in association with each other.
In addition, the rainfall-inflow water amount correlation database 26 shows the relationship between the rainfall information such as the rainfall amount in the treatment area measured by the rain gauge in the past and the inflow water amount of the sewage 100 (the inflow water amount to the water treatment device 2). It is stored in association with each other. A rainfall radar may be used instead of the rain gauge.
The organic matter concentration time change database 27 of the sewage stores the time change of the organic matter concentration of the sewage 100.

The measurement value acquisition unit 24 first measures the flow rate of the sewage 100 measured by the first flow meter 10 installed on the upstream side of the settling basin 4, and the organic matter of the sewage 100 measured by the UV meter 11 as a water quality meter. The concentration is acquired via the communication I / F 28 and the internal bus 33. In addition, the measurement value acquisition unit 24 initially measures the flow rate of the aerobic tank inflow water 101 measured by the second flow meter 12 installed in the flow path of the aerobic tank (reaction tank) 5 from the sedimentation pond 4. Rainfall information such as the measured value of the active sludge concentration in the aerobic tank (reaction tank) 5 measured by the sludge concentration meter 13 and the rainfall measured by the rain gauge is transmitted via the communication I / F28 and the internal bus 33. get. The measurement value acquisition unit 24 performs a process such as noise reduction on the acquired flow rate measurement value of the sewage 100 and the organic matter concentration of the sewage 100, and the inflow water amount / water quality prediction unit 21 and the processing amount via the internal bus 33. Transfer to the control unit 23. Further, the measurement value acquisition unit 24 can process the acquired flow rate measurement value of the aerobic tank inflow water 101 with the inflow water amount / water quality prediction unit 21 via the internal bus 33, for example, by performing a process such as noise reduction. Transfer to the quantity calculation unit 22. Similarly, the measured value acquisition unit 24 applies a process such as noise removal to the acquired measured value of the activated sludge concentration in the aerobic tank (reaction tank) 5, and the amount that can be processed via the internal bath 33. In addition to transferring to the calculation unit 22, rainfall information such as the acquired rainfall amount is transferred to the rainfall information acquisition unit 20.

The inflow water amount / water quality prediction unit 21 is a flow rate measurement value (measured flow rate of the sewage 100) of the sewage 100 measured by the first flow meter 10 transferred from the measurement value acquisition unit 24 and a rainfall information acquisition unit 20. The future flow rate of sewage 100 is predicted based on rainfall information such as the amount of rainfall in the treatment area. Further, the inflow water amount / water quality prediction unit 21 is used to measure the flow rate of the sewage 100 (measured flow rate of the sewage 100) measured by the first flow meter 10 transferred from the measurement value acquisition unit 24, and UV as a water quality meter. The future organic concentration of the sewage 100 is predicted based on the organic matter concentration of the sewage 100 measured by the total 11 and the rainfall information such as the amount of rainfall in the treatment area from the rainfall information acquisition unit 20.

The processable amount calculation unit 22 is based on the measured value of the activated sludge concentration in the aerobic tank (reaction tank) 5 measured by the sludge concentration meter 13 transferred from the measurement value acquisition unit 24, and the biological treatment amount in a predetermined time. That is, the upper limit of the flow rate of the aerobic tank inflow water 101 is calculated.

The processing amount control unit 23 has a predetermined time according to the current and future flow rate and water quality of the sewage 100 within the range of the flow rate upper limit of the aerobic tank inflow water 101 calculated by the processable amount calculation unit 22. The flow rate set value of the aerobic tank inflow water 101 at each time is calculated and compared with the flow rate measurement value of the aerobic tank inflow water 101 transferred from the measurement value acquisition unit 24 by the second flow meter 12.

The movable weir 14 is initially installed in the flow path from the settling basin 4 to the aerobic tank (reaction tank) 5, and is electrically connected to the processing amount control unit 23 via a signal line. The movable weir 14 controls the weir height so that the flow rate measurement value of the aerobic tank inflow water 101 by the second flow meter 12 becomes equal to the value calculated by the processing amount control unit 23. In other words, the processing amount control unit 23 sets the flow rate set value of the aerobic tank inflow water 101 at each time within the predetermined time calculated above and the flow rate measurement value of the aerobic tank inflow water 101 by the second flow meter 12. The control amount of the weir height is transmitted to the movable weir 14 via the output I / F 30 so that Here, the weir height of the movable weir 14 is adjusted (controlled) automatically or manually.

Next, the method of predicting the flow rate of the sewage 100 in the inflow water amount / water quality prediction unit 21 will be outlined. First, the inflow water amount / water quality prediction unit 21 acquires the flow rate measurement value of the sewage 100 (measured flow rate of the sewage 100) measured by the first flow meter 10 transferred from the measurement value acquisition unit 24 as described above. At the same time, the sewage flow rate time change database 25 is accessed via the internal bus 33, and the future of sewage excluding rainwater is based on the time change of the flow rate of the sewage 100 as the past actual data stored in the sewage flow rate time change database 25. Predict the flow rate of. At the same time, the inflow water amount / water quality prediction unit 21 acquires rainfall information such as the amount of rainfall in the treatment area by the rainfall information acquisition unit 20, and accesses the rainfall amount-inflow water amount correlation database 26 via the internal bus 33. Then, based on the relationship between the rainfall information such as the rainfall in the treatment area measured by the rain gauge 13 in the past and the inflow of sewage stored in the rainfall-inflow correlation database 26, the future inflow of rainwater Predict. Then, the inflow water amount / water quality prediction unit 21 totals the predicted future sewage 100 flow rate and the future rainwater inflow amount, and predicts the sewage 100 flow rate.

In addition, the method for predicting the water quality of the sewage 100 in the inflow water amount / water quality prediction unit 21 will be outlined. First, the inflow water amount / water quality prediction unit 21 acquires the organic substance concentration of the sewage 100 measured by the UV meter 11 as a water quality meter transferred from the measurement value acquisition unit 24 as described above, and also via the internal bus 33. Access the organic substance concentration time change database 27 of the sewage, and predict the future organic substance concentration of the sewage excluding rainwater based on the organic substance concentration time change of the sewage 100 stored in the organic substance concentration time change database 27 of the sewage. Then, the inflow water amount / water quality prediction unit 21 predicts the organic matter concentration of the future sewage 100 in consideration of the dilution effect from the sewage flow rate prediction value excluding rainwater and the rainwater inflow amount prediction value.

The above-mentioned rainfall information acquisition unit 20, inflow water amount / water quality prediction unit 21, processable amount calculation unit 22, processing amount control unit 23, and measurement value acquisition unit 24 include, for example, a processor such as a CPU (not shown) and various programs. It is realized by a storage device such as a ROM to store, a RAM to temporarily store data of the calculation process, and an external storage device, and a processor such as a CPU reads and executes various programs stored in the ROM, and the execution result is used. A certain calculation result is stored in a RAM or an external storage device.

(Operation of water treatment control device 3)
Next, the operation of the water treatment control device 3, that is, the flow rate control method of the aerobic tank inflow water 101 into the aerobic tank (reaction tank) 5 will be described.
FIG. 3 is a flow rate control flow chart of the amount of inflow water into the aerobic tank (reaction tank) 5 by the water treatment control device 3 shown in FIG. As shown in FIG. 3, in step S101, the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101 per unit time and the activated sludge interface upper limit (Hup) in the final settling basin 6 are input to the input unit 31 based on the facility conditions and the like. Set via.

Next, in step S102, the processable amount calculation unit 22 measures the sludge concentration (X (t)) in the aerobic tank (reaction tank) 5 by the sludge concentration meter 13 via the internal bus 33. Obtain from 24.
In step S103, the processable amount calculation unit 22 integrates the aerobic tank inflow water 101 in a predetermined period based on the sludge concentration (X (t)) in the aerobic tank (reaction tank) 5 acquired in step S102. The upper limit of the flow rate (Qt_all_up (t)) is calculated (the upper limit of the flow rate of the aerobic tank inflow water 101 is calculated).

In step S104, the inflow water amount / water quality prediction unit 21 determines the flow rate measurement value (Qin (t)) of the sewage 100 measured by the first flow meter 10 transferred from the measurement value acquisition unit 24, and the UV meter as a water quality meter. Rainfall information such as the organic substance concentration (Cin (t)) of the sewage 100 measured by 11 and the amount of rainfall in the treatment area from the rainfall information acquisition unit 20 is acquired.
In step S105, the inflow water amount / water quality prediction unit 21 determines the future flow rate of the sewage 100 (Qin (t + n · Δt)) based on the flow rate measurement value (Qin (t)) of the sewage 100 and the rainfall information acquired in step S104. ) Predict. Further, the inflow water amount / water quality prediction unit 21 determines the organic matter concentration (Cin (t + n · Δt)) of the future sewage 100 based on the organic matter concentration (Cin (t)) of the sewage 100 and the rainfall information acquired in step S104. Predict.

In step S106, the processing amount control unit 23 sets the integrated flow rate upper limit Qt_all_up (t) of the aerobic tank inflow water 101 in the predetermined period calculated by the processingable amount calculation unit 22 in the above-mentioned step S103, and the above-mentioned step. Based on the organic matter concentration (Cin (t + n · Δt)) which is the water quality of the future sewage 100 calculated by the inflow water amount / water quality prediction unit 21 in S105, the flow rate set value of the aerobic tank inflow water 101 at each time ( Qt (t + n · Δt)) is calculated.
In step S107, the processing amount control unit 23 determines the flow rate set value (Qt (t + n · Δt)) of the aerobic tank inflow water 101 at each time calculated in step S106, and per unit time set in step S101. It is compared with the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101. As a result of comparison, if the flow rate set value (Qt (t + n · Δt)) of the aerobic tank inflow water 101 at each time is smaller than the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101 per unit time, the process proceeds to step S108. .. On the other hand, as a result of comparison, when the flow rate set value (Qt (t + n · Δt)) of the aerobic tank inflow water 101 at each time is equal to or greater than the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101 per unit time, step S109. Proceed to.

In step S108, the processing amount control unit 23 sets the aerobic tank inflow water 101 at time t + n · Δt as the flow rate set value (Qt (t + n · Δt)) of the aerobic tank inflow water 101 calculated in step S106, and steps. Return to S102.
In step S109, the processing amount control unit 23 sets the aerobic tank inflow water 101 at time t + n · Δt as the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101 per unit time, and returns to step S102.

Here, the integrated flow rate upper limit (Qt_all_up (t)) of the aerobic tank inflow water 101 in the predetermined period in step S103, and the flow rate set value of the aerobic tank inflow water 101 at each time in step S106 (Qt (t + n. The calculation method of Δt)) will be outlined. The method shown below is an example and is not necessarily limited to this.
First, using the following formula (1), the activated sludge interface upper limit Hup (m) is subtracted from the effective water depth Hs (m) to calculate at least the water depth ΔHmin (m) to be settled.

Next, the initial activated sludge concentration X (t) (mg / L) and the average value Xav (t) (mg / L) of the activated sludge concentration when settling to the activated sludge interface upper limit Hup (m) are as follows. Calculated by equation (2).

Then, the average value vav (t) (m / min) of the activated sludge sedimentation rate, which is a function of the activated sludge concentration, is calculated by the following formula (3).

From the calculated values of equations (1) and (3) and the volume V (m ³ ) of the final settling pond 6, the upper limit of the flow rate at which the active sludge interface is Hup (m) or less at the outflow part from the final settling pond 6 Quant (t) (m ³ / min) is calculated by the following formula (4), and further, the integrated flow rate upper limit (Qt_all_up (t)) (Qt_all_up (t)) of the aerobic tank inflow water 101 in a predetermined period (N · Δt) ( m ³ ) is calculated by the following formula (5). Here, the predetermined period (N · Δt) is appropriately set, for example, 30 minutes or 1 hour. Taking the case of rainfall as an example, for example, the time when the rainfall information is acquired by the rainfall information acquisition unit 20 is used as a trigger to calculate every 5 minutes or every 10 minutes for up to 1 hour.

The above equation (4) is a modification of V / Cup (t) = ΔHmin / vav (t), and V / Cup (t) on the left side is a horizontal condition (retention in the final settling basin 6). (Represents time), and ΔHmin / vav (t) on the right side is a vertical condition (represents the time required to sink by ΔHmin).

In step S106 described above, the flow rate set value (Qt (t + n · Δt)) of the aerobic tank inflow water 101 at each time is calculated according to the following formula (6).

Generally, the amount of inflow water into the aerobic tank (reaction tank) 5 is set to be equal to or less than the planned amount of water, or the operation manager sets the amount of water based on the activated sludge sedimentation condition in the final sedimentation basin 6. In this embodiment, the flow rate of the activated sludge inflow water 101 in the aerobic tank is maximized within the range where the activated sludge interface in the final settling basin 6 is below the upper limit, thereby suppressing the outflow of activated sludge and the simple treatment discharge water 103. The amount of water can be reduced. Further, by setting the flow rate of the aerobic tank inflow water 101 according to the water quality of the sewage 100, it is possible to reduce the discharge pollution load by selectively treating more high-concentration sewage.
In this embodiment, the water treatment apparatus 1 to which the standard activated sludge method has been introduced has been described as an example. However, for example, the anaerobic aerobic activated sludge method, the circulating nitrification denitrification method, etc. Any treatment method using sludge can be applied in the same manner.

In this embodiment, the first flow meter 10 and the UV meter 11 are installed upstream of the first settling basin 4, but may be installed between the first settling basin 4 and the aerobic tank (reaction tank) 5. .. For example, the first flow meter 10 may be installed between the first settling basin 4 and the flow path branch point of the simple treated effluent 103, and the flow rate of the effluent from the first settling basin 4 may be measured. Similarly, the UV meter 11 may be initially installed downstream of the settling basin 4 to measure the organic matter concentration of the aerobic tank inflow water 101 or the simple treated effluent 103.

In this embodiment, the UV meter 11 is used as the water quality meter, but instead of this, any device such as a COD meter that can estimate and measure the concentration of organic matter may be used. Further, in this embodiment, the water quality of the sewage 100 is organic, but nitrogen, phosphorus, or the like may be used. For example, an ammonia meter may be used as the water quality meter.

In this embodiment, the second flow meter 12 was first installed in the flow path of the settling basin 4 or the aerobic tank (reaction tank) 5, but it is not always necessary to install the second flow meter 12 in the sewage 100 by the first flow meter 10. The flow rate of the aerobic tank inflow water 101 may be estimated from the flow rate measurement value and the weir height of the movable weir 14.

In this embodiment, the movable weir 14 was first installed in the flow path of the aerobic tank (reaction tank) 5 from the settling basin 4 to control the flow rate of the aerobic tank inflow water 101, but instead of this, it is movable. The weir 14 may be installed in the flow path of the simple treatment discharge water 103 to control the flow rate of the simple treatment discharge water 103. In this case, the flow rate of the simple treatment discharge water 103 is a value obtained by subtracting the sludge withdrawal amount at the first settling basin 4 and the flow rate of the aerobic tank inflow water 101 calculated by the formula (6) from the flow rate of the sewage 100. .. In this embodiment, the flow rate set value of the aerobic tank inflow water 101 was calculated in step S108 or step S109, but after that, a step to compare with the flow rate measurement value of the sewage 100 is added, and the flow rate measurement value of the sewage 100 is added. If is larger, the set value calculated in step S108 or step S109 may be used, and if the flow rate measurement value of the sewage 100 is smaller, the flow rate measurement value of the sewage 100 may be used as the set value.

As described above, according to the present embodiment, even when the inflow flow rate and the inflow water quality of sewage (water to be treated) fluctuate, water that can secure the maximum amount of biological treatment within a range that can prevent sludge outflow. It becomes possible to provide a treatment control device and a water treatment system.
Further, according to this embodiment, it is possible to reduce the amount of simply treated effluent while suppressing the outflow of activated sludge.
Further, according to this embodiment, it is possible to reduce the discharge pollution load by selectively treating more high-concentration sewage with biological treatment.

FIG. 4 is a schematic overall configuration diagram of the water treatment system of the second embodiment according to another embodiment of the present invention, and FIG. 5 is a functional block diagram of the water treatment control device shown in FIG. In Example 1 described above, the upper limit of the flow rate of the aerobic tank inflow water 101 is set to Up (t) by the above formula (4) using the measured values of the sludge concentration meter 13 installed in the aerobic tank (reaction tank) 5. It was configured to be calculated. On the other hand, in the present embodiment, in addition to the configuration of the first embodiment, the sludge interface meter 15 is installed in the final settling basin 6 and the water treatment control device 3a further has the sludge sedimentation evaluation unit 34. Different from. The same components as in the first embodiment are designated by the same reference numerals, and a part of the description overlapping with the first embodiment will be omitted below.

As shown in FIG. 4, the water treatment system 1a according to the present embodiment removes organic substances and the like from domestic wastewater or sewage (treated water) such as industrial wastewater by using activated sludge in the standard activated sludge method. A water treatment device 2a and a water treatment control device 3a are provided.
The water treatment device 2a includes a sludge interface meter 15 installed in the final settling basin 6. Other configurations are the same as those in the first embodiment described above, and the description thereof will be omitted. The sludge interface meter 15 is installed on the downstream side in the final settling basin 6, and the measured value of the activated sludge interface in the final settling basin 6 measured by the sludge interface meter 15 is controlled by water treatment via a signal line. It is output to the device 3a.

As shown in FIG. 5, the water treatment control device 3a includes a rainfall information acquisition unit 20, an inflow water amount / water quality prediction unit 21, a treatable amount calculation unit 22, a treatment amount control unit 23, a sludge sedimentation evaluation unit 34, and measurement value acquisition. Part 24, sewage flow rate time change database 25, rainfall-inflow water amount correlation database 26, sewage organic substance concentration time change database 27, communication I / F28, input I / F29 and output I / F30, which are mutually internal. It is connected via the bus 33. Further, the input I / F 29 is connected to the input unit 31, and is input via the input unit 31. The upper limit of the flow rate of the aerobic tank inflow water 101 per unit time based on the facility conditions and the like, and the sludge in the final settling basin 6. Incorporate the upper limit of the interface. The output I / F 28 is connected to the display unit 32, and the display unit 32 displays desired information on the screen, for example, various set values or rainfall information in the processing area as needed. Although not shown, the water treatment control device 3 also has a function of controlling the blower 8 in order to control the amount of aerated air supplied to the aerobic tank (reaction tank) 5 via the air diffuser 7. There is. In this embodiment, the case where the water treatment control device 3 has the rainfall information acquisition unit 20 will be described as an example.

The measured value of the activated sludge interface in the final settling basin 6 measured by the sludge interface meter 15 is transferred to the measured value acquisition unit 24 via the communication I / F 28 and the internal bus 33. The measured value acquisition unit 24 performs a process such as noise removal on the acquired measured value of the activated sludge interface in the final sedimentation basin 6 and transfers it to the sludge sedimentation evaluation unit 34 via the internal bus 33.
The sludge sedimentation evaluation unit 34 sets the upper limit of the activated sludge interface in the final sedimentation basin 6 set in advance and the activated sludge interface in the final sedimentation basin 6 measured by the sludge interface meter 15 transferred from the measurement value acquisition unit 24. Compare with the measured value.
Further, the processable amount calculation unit 22 is the measured value of the activated sludge concentration in the aerobic tank (reaction tank) 5 measured by the sludge concentration meter 13 transferred from the measured value acquisition unit 24, and the measured value acquisition unit 24. Based on the measured value of the activated sludge interface in the final sedimentation pond 6 measured by the sludge interface meter 15 transferred from the above, the amount of biological treatment in a predetermined time by the above formula (6), that is, the aerobic tank inflow water 101. Calculate the upper limit of the flow rate.

The above-mentioned rainfall information acquisition unit 20, inflow water amount / water quality prediction unit 21, processable amount calculation unit 22, processing amount control unit 23, sludge sedimentation evaluation unit 34, and measurement value acquisition unit 24 are, for example, CPUs (not shown) or the like. It is realized by a storage device such as a CPU, a ROM that stores various programs, a RAM that temporarily stores data of the calculation process, and an external storage device, and a processor such as a CPU reads various programs stored in the ROM. It is executed and the calculation result which is the execution result is stored in the RAM or the external storage device.

Next, the operation of the water treatment control device 3a, that is, the flow rate control method of the aerobic tank inflow water 101 into the aerobic tank (reaction tank) 5 will be described.
FIG. 6 is a flow rate control flow chart of the amount of inflow water into the aerobic tank (reaction tank 5) by the water treatment control device 3a shown in FIG. As shown in FIG. 6, in S201, the flow rate upper limit (Qt_up) of the aerobic tank inflow water 101 per unit time, the activated sludge interface upper limit (Hup) in the final settling basin 6 are set by the input unit 31 based on the facility conditions and the like. Set through.

Next, in step S202, the sludge sedimentation evaluation unit 34 obtains the measured value (H (t)) of the activated sludge interface in the final sedimentation basin 6 by the sludge interface meter 15 via the internal bus 33. Get from.
In step S203, the sludge sedimentation evaluation unit 34 was set with the measured value (H (t)) of the activated sludge interface in the final sedimentation basin 6 by the sludge interface meter 15 acquired in step S202 and in step S201. Compare with the activated sludge interface upper limit (Hup) in the final settling basin 6. As a result of comparison, if the measured value (H (t)) of the activated sludge interface in the final settling basin 6 by the sludge interface meter 15 is smaller than the activated sludge interface upper limit (Hup) in the final settling basin 6, the process proceeds to step S204. On the other hand, as a result of comparison, when the measured value (H (t)) of the activated sludge interface in the final settling basin 6 by the sludge interface meter 15 is equal to or higher than the upper limit (Hup) of the activated sludge interface in the final settling basin 6, step S205. Proceed to.

In step S205, the processing amount control unit 23 fixes the upper limit of the flow rate of the aerobic tank inflow water 101 to a predetermined value (Qt_up_tp) set in advance such as the planned water amount, and returns to step S202.
Since steps S204 and steps S206 to S212 are the same as steps S102 to S109 shown in FIG. 3 in the above-described first embodiment, description thereof will be omitted here.

With the above configuration, the activated sludge settling condition in the final settling basin 6 is monitored, and the upper limit of the flow rate of the aerobic tank inflow water 101 is calculated to more reliably suppress the activated sludge outflow from the final settling basin 6. It becomes possible.
In this embodiment, the sludge interface meter 16 is installed in order to measure the activated sludge interface in the final sedimentation basin 6, but the present invention is not limited to this. For example, instead of the sludge interface meter 16, a SS concentration meter or a turbidity meter that can measure or estimate the active sludge concentration of the treated water 104 may be used, and in these cases, the installation position is the final sedimentation pond 6. It may be anywhere in the flow path of the treated water 104.

As described above, according to the present embodiment, in addition to the effect of the first embodiment, it is possible to more reliably suppress the outflow of activated sludge from the final settling basin 6.

The present invention is not limited to the above-described examples, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

1,1a ... Water treatment system 2,2a ... Water treatment device 3,3a ... Water treatment control device 4 ... First settling basin 5 ... Aerobic tank (reaction tank)
6 ... Final settling pond 7 ... Air diffuser 8 ... Blower 9 ... Return pump 10 ... First flow meter 11 ... UV meter 12 ... Second flow meter 13 ... Sewage concentration meter 14 ... Movable dam 15 ... Sewage interface meter 20 ... Rainfall Information acquisition unit 21 ... Inflow water amount / water quality prediction unit 22 ... Processable amount calculation unit 23 ... Processing amount control unit 24 ... Measurement value acquisition unit 25 ... Sewage flow rate time change database 26 ... Rainfall-inflow water amount correlation database 27 ... Sewage Organic substance concentration time change database 28 ... Communication I / F
29 ... Input I / F
30 ... Output I / F
31 ... Input unit 32 ... Display unit 33 ... Internal bus 34 ... Sewage sludge sedimentation evaluation unit 100 ... Sewage 101 ... Aerobic tank inflow water 102 ... Activated sludge 103 ... Simple treated discharge water 104 ... Treated water 105 ... Return sludge

Claims (6)

Water having at least a reaction tank in which part or all of the sewage to be treated is treated with active sludge, and a final sedimentation pond in which the effluent flowing out of the reaction tank is settled and separated into active sludge and treated water. A water treatment control device that controls the treatment device.
Inflow water volume / water quality prediction unit that predicts future sewage flow rate and water quality,
A processable amount calculation unit that calculates the upper limit of the amount of water flowing into the reaction tank,
A processing amount control unit for controlling the amount of water flowing into the reaction vessel is provided.
The processing amount control unit controls the inflow water amount into the reaction tank based on the output value of the inflow water amount / water quality prediction unit and the output value of the processable amount calculation unit .
The processable amount calculation unit obtains an upper limit of the amount of water flowing into the reaction tank based on the measured value of the activated sludge concentration in the reaction tank measured by the sludge densitometer.
The treatment amount control unit calculates the inflow water amount into the reaction tank based on the upper limit of the inflow water amount to the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. A water treatment control device characterized by the fact that. Water having at least a reaction tank in which part or all of the sewage to be treated is treated with active sludge, and a final sedimentation pond in which the effluent flowing out of the reaction tank is settled and separated into active sludge and treated water. A water treatment control device that controls the treatment device.
Inflow water volume / water quality prediction unit that predicts future sewage flow rate and water quality,
A processable amount calculation unit that calculates the upper limit of the amount of water flowing into the reaction tank,
A processing amount control unit for controlling the amount of water flowing into the reaction vessel is provided.
The processing amount control unit controls the inflow water amount into the reaction tank based on the output value of the inflow water amount / water quality prediction unit and the output value of the processable amount calculation unit.
The processable amount calculation unit is the measured value of the active sludge concentration in the reaction tank measured by the sludge concentration meter, the measured value of the active sludge interface of the final sedimentation pond measured by the sludge interface meter, or the final sedimentation pond. Based on the SS concentration or turbidity of the treated water, the upper limit of the amount of water flowing into the reaction tank was determined.
The treatment amount control unit calculates the inflow water amount into the reaction tank based on the upper limit of the inflow water amount to the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. A water treatment control device characterized by the fact that. In the water treatment control device according to claim 1 or 2.
Equipped with a rainfall information acquisition unit that acquires rainfall information including the amount of rainfall in the treatment area.
The inflow water volume / water quality prediction unit
The future sewage flow rate is predicted based on the sewage flow measurement value and the rainfall information by the flow meter, and the future sewage flow rate is predicted based on the sewage water quality measurement value and the flow rate measurement value and the rainfall information by the water quality meter. A water treatment control device characterized by predicting the quality of sewage . A water treatment apparatus having at least a reaction tank for treating a part or all of the sewage to be treated with activated sludge, and a final settling pond for separating the effluent flowing out of the reaction tank into activated sludge and treated water. ,
Inflow water amount / water quality prediction unit that predicts future sewage flow rate and water quality, processable amount calculation unit that calculates the upper limit of inflow water amount to the reaction tank, and processing amount that controls the inflow water amount to the reaction tank. A water treatment control device including a control unit,
The processing amount control unit controls the inflow water amount into the reaction tank based on the output value of the inflow water amount / water quality prediction unit and the output value of the processable amount calculation unit.
The processable amount calculation unit obtains an upper limit of the amount of water flowing into the reaction tank based on the measured value of the activated sludge concentration in the reaction tank measured by the sludge densitometer .
The treatment amount control unit calculates the inflow water amount into the reaction tank based on the upper limit of the inflow water amount to the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. A water treatment system characterized by this. A water treatment apparatus having at least a reaction tank for treating a part or all of the sewage to be treated with activated sludge, and a final settling pond for separating the effluent flowing out of the reaction tank into activated sludge and treated water. ,
Inflow water amount / water quality prediction unit that predicts future sewage flow rate and water quality, processable amount calculation unit that calculates the upper limit of inflow water amount to the reaction tank, and processing amount that controls the inflow water amount to the reaction tank. A water treatment control device including a control unit,
The processing amount control unit controls the inflow water amount into the reaction tank based on the output value of the inflow water amount / water quality prediction unit and the output value of the processable amount calculation unit.
The processable amount calculation unit is the measured value of the active sludge concentration in the reaction tank measured by the sludge concentration meter, the measured value of the active sludge interface of the final sedimentation pond measured by the sludge interface meter, or the final sedimentation pond. Based on the SS concentration or turbidity of the treated water, the upper limit of the amount of water flowing into the reaction tank was determined.
The treatment amount control unit calculates the inflow water amount into the reaction tank based on the upper limit of the inflow water amount to the reaction tank and the output value of the inflow water amount / water quality prediction unit obtained by the treatable amount calculation unit. A water treatment system characterized by that. In the water treatment system according to claim 4 or 5 .
The water treatment device includes a flow meter for measuring the flow rate of the sewage and a water quality meter for measuring the water quality of the sewage.
The water treatment control device has a rainfall information acquisition unit that acquires rainfall information including the amount of rainfall in the treatment area.
The inflow water amount / water quality prediction unit predicts the future sewage flow rate based on the sewage flow rate measurement value by the flow meter and the rainfall information, and also determines the sewage water quality measurement value and the flow rate measurement value by the water quality meter. A water treatment system characterized by predicting the water quality of the future sewage based on rainfall information .

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