JP2002045844A - Water quality simulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water quality simulation system which can shorten the time for simulation. SOLUTION: This water quality simulation system has a data accumulation device 1 which accumulates the water quality data of a sewage disposal plant, a disposal plant specification setting device 2 which sets the disposal plant specifications, such as civil engineering construction, an operating condition setting device 3 which sets operating conditions, a model parameter setting device 4 which sets water quality model parameters, and a simulation calculating device which receives the data from the respective devices and predicts the water quality of the disposal plant to predict the water quality of the disposal plant and is provided with a prediction interval setting device 7 which changes the prediction interval of the simulation, an organic matter deciding device 6 which decides the organic matter data of fermentation products, fermentable and easily biodegradable organic substrates, or the like, from the data of the data accumulation device, and a prediction interval fine segmenting device 71 which segments the prediction intervals of the simulation calculating device when the value by the organic matter deciding device exceeds a reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality simulation apparatus for determining a treatment method when purifying wastewater such as municipal sewage or industrial wastewater by an activated sludge method, an anaerobic / aerobic sludge treatment method, or the like.

[0002]

2. Description of the Related Art It is necessary to determine an operation method of a treatment process such as municipal sewage treatment and industrial wastewater from the operating state of microorganisms, climate and the like. FIG. 3 is a block diagram showing a connection state between a conventional water quality simulation apparatus and its surroundings.
First, the outline of the sewage treatment plant will be described. In the figure, 10 is a first settling tank, 11 is a reaction tank, and 12 is a final settling tank. In a sewage treatment plant, the incoming sewage is
The first sedimentation basin 10, the reaction tank 11, and the final sedimentation basin 12 flow in this order and are treated. The sewage containing pollutants is the first settling basin 1
Then, the sediment that is likely to settle out of the pollutants is settled and separated, and the supernatant water flows out to the reaction tank 11. A part of the sludge from the final settling tank 12 is returned to the reaction tank 11 by a return sludge pump. The reaction tank 11 processes the returned sludge and the supernatant water of the first settling tank 10. In the reaction tank 11, air fed from a blower (not shown) is released by a diffuser pipe in the aeration tank, and pollutants are adsorbed and decomposed by activated sludge and guided to the final sedimentation basin 12. In the final sedimentation basin 12, the activated sludge is settled and separated, the settled sludge is discharged to a sludge treatment system (not shown) by an excess sludge pump (not shown), and the clarified water is treated in a sterilization tank (not shown) as treated water. It is released after passing through. Next, the operation of the water quality simulation apparatus will be described. In FIG. 2, 1 is a data storage device,
2 is a treatment plant specification setting device, 3 is an operation condition setting device, 4 is a model parameter setting device, and 5 is a simulation calculation device. (1) Water quality measurement / analysis data is stored in the data storage device 1. The data storage device 1 provides information necessary for simulating the water quality from the sampling points a, b, c, and d, for example, the concentration of phosphate phosphorus, the concentration of nitrate nitrogen,
It accumulates data on analyzed water quality such as ammonia nitrogen concentration, Total-COD, and soluble COD. (2) The treatment plant civil engineering structure such as the volume of the reaction tank and the pipeline is set by the treatment plant specification setting device 2. (3) For the conditions necessary for operating the treatment plant, such as the return rate, SRT, and DO concentration, the most suitable values for each treatment plant are set by the operation condition setting device 3. (4) Water quality model parameters used for simulation
(Growth rate, decomposition rate, etc.) are set by the model parameter setting device 4. (5) The prediction calculation is performed by the simulation device 5. Of the analysis data stored in the storage device 1, the quality of the water flowing into the inlet of the sewage treatment plant, the value input to the treatment plant specification setting device 2, the value set by the operation condition setting device 3,
The values set by the model parameter setting device 4 are input, and the reaction tank and the quality of the treated water are predicted. There are more than ten formulas used for the prediction calculation. For example, calculation of the fermentation product concentration is performed by using the formula (1).

[0003]

(Equation 1)

However, the meaning of each symbol is as follows. SA (i): Fermentation product concentration (gCOD /
m ³ ) SA (i) _R: Concentration of fermentation product (gN / m ³ ) taking into account the change due to chemical reaction _in the target tank at time i SA (i) _in : Fermentation flowing into the target tank at time i Product concentration (gCOD / m ³ ) SA (i) _out : Fermentation product concentration (gCOD / m ³ ) flowing out of the target tank at time i V: Volume of the target tank (m ³ ) Q _in : Flow into the target tank the amount of _{^{(m 3 / h) Q out}} : the amount flowing out of the target tank (m ³ / h) T: time to flow in or out from the subject tank (h) i: prediction interval for simulation (h) where each Variables are calculated as shown in (2) to (9).

[0005]

(Equation 2)

However, the meaning of each symbol is as follows. SA (i): Fermentation product (gCOD / m ³ ) that grew and decreased in the target tank at the time i. Ρ ₅ : Aerobic growth with SA (gCOD / d). Ρ ₇ : Anoxic growth and denitrification with SA. (gCOD / d) ρ ₈ : Fermentation (gCOD / d) ρ ₁₀ : Storage of polyhydroxyalkanoate (gCOD / d) ρ ₁₅ : Decomposition of polyhydroxyalkanoate (gCOD / d) Input from the data storage device 1 Analytical data S _O2 : dissolved oxygen concentration (gO ₂ / m ³ ) S _NH4 soluble ammonia concentration (gN / m ³ ) S _NO3 : soluble nitrate nitrogen concentration (gN / m ³ ) S _PO4 : inorganic dissolved Phosphoric acid phosphorus concentration (gP / m ³ ) S _ALK : alkalinity (mole HCO3 / m ³ ) S _F : easily decomposable organic matter concentration (gCOD / m ³ ) S _A : Fermentation product concentration (gCOD / m ³ ) X _AUT : nitrifying bacteria concentration (gCOD / m ³ ) X _H : heterotrophic microorganism (gCOD / m ³ ) X _PHA : polyhydroxyalkanoate (gCOD / m ³ ) X _PP : polyphosphoric acid (gP / m ³ ) X _PAO phosphate accumulating organisms (gCOD / m ³⁾ model parameter set Parameters set from the device 4 to, is as follows. u _H : maximum growth rate of substrate (1 / d) η _NO3 : reduction coefficient of nitrate nitrogen concentration by anoxic hydrolysis (-) k _A : fermentation product concentration saturation coefficient (gO ₂ / m ³ ) k _O2 : oxygen saturation coefficient (gO ₂ / m ³ ) k _F : readily degradable substrate growth saturation coefficient (gCOD / m ³ ) k _NO3 : nitrate nitrogen saturation coefficient (gN / m ³ ) In this simulation, nitrite nitrogen and nitrate nitrogen are treated as the same substance. k _NH4 : Ammonia saturation coefficient (gN / m ³ ) k _P : Phosphate phosphoric acid saturation coefficient (gP / m ³ ) k _ALK : Alkaline saturation coefficient (mole HCO3 / m ³ ) k _fe : Fermentation saturation concentration of SF ( gCOD / m ³ ) q _fe : Maximum fermentation rate (1 / d) k _PP : Saturated concentration of polyphosphoric acid (gPP / gPAO) q _PHA : Polyhydroxyalkanoate accumulation rate (gCOD /
(gPAO.d) b _PHA : Decomposition rate of polyhydroxyalkanoate (1 / d) In the simulation calculation device 5, not only the nitrate nitrogen but also the phosphate phosphorus concentration, alkalinity, ammonia nitrogen concentration, etc. Calculated at the same time.

[0007]

However, in the conventional water quality simulation apparatus as described above, fermentation products,
The prediction interval for simulation is usually set to, for example, 1 regardless of the amount of organic substances such as easily decomposable organic substances and the amount of change in water quality.
It was fixed as short as seconds. Therefore, there is a problem that the simulation time becomes long. In addition, there is a problem that it takes a long simulation time even when a large number of reaction vessels are present. Therefore, the present invention has been made in view of such a problem, and it is possible to set the prediction interval of the simulation based on the amount of organic matter in the water quality simulation, the amount of change in the water quality, and to reduce the number of the simulation tanks depending on the state of the reaction tank. Accordingly, an object of the present invention is to provide a water quality simulation device capable of reducing the simulation time.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a data storage device for storing water quality data of a sewage treatment plant consisting of a primary sedimentation site, a reaction tank, a final sedimentation site, and the like. A treatment plant specification setting device that sets treatment plant specifications, an operation condition setting device that sets operation conditions, a model parameter setting device that sets water quality model parameters, and receives data from the devices to predict water quality of the treatment plant A simulation calculation device for predicting the water quality of the treatment plant,
A prediction interval setting device that changes a prediction interval between the data storage device and the simulation calculation device; and determining data of an organic substance such as a fermentation product and a fermentable biodegradable organic substrate from the data of the data storage device. And a prediction interval subdivision device that further divides the prediction interval to perform a simulation when a value obtained by the organic substance determination device exceeds a reference value. The organic matter determination device may include a change amount determination device that determines a change amount of water quality by the simulation calculation device or a concentration determination device that determines the concentration of the organic matter. In addition, a data storage device for storing water quality data of a sewage treatment plant consisting of a first sedimentation site, a reaction tank, and a final sedimentation site, a treatment plant specification setting device for setting a treatment plant specification such as a civil engineering structure, and an operating condition are set. A water quality simulation comprising an operating condition setting device for setting, a model parameter setting device for setting a water quality model parameter, and a simulation calculating device for receiving data from the respective devices and for predicting the water quality of the treatment plant for predicting the water quality of the treatment plant In the apparatus, between the data storage device and the simulation calculation device, a DO determination device that determines DO data of each tank of the reaction tank, and a tank change device that changes a tank of the reaction tank are provided. I have. Further, the tank changing device is provided with the DO
After checking the signal from the judging device, a tank synthesizing device for synthesizing and simulating the tanks or a tank dividing device for dividing and simulating the reaction tank may be provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a first embodiment of the present invention. Figure 1
FIG. 3 is a block diagram of a configuration of a water quality simulation apparatus and a connection status with the periphery thereof. In the figure, reference numeral 6 denotes an organic substance determination device, 7 denotes a prediction interval setting device for setting a prediction interval, and 71 denotes a prediction interval dividing device for further dividing the prediction interval. The organic substance determination device 6 includes a change amount determination device 61 and a concentration determination device 62. The other symbols and a, b, c, and d indicating the sampling points are the same as those described in the section of the related art, and thus description thereof is omitted. Next, the operation of the water quality simulation apparatus will be described. (1) The water quality measurement / analysis data is stored in the data storage device 1 (same as the conventional technology). (2) The treatment plant civil engineering structure is set by the treatment plant specification setting device 2 (same as the conventional technology). (3) The most suitable values for the treatment plant, such as the return rate, SRT, and DO concentration, are set by the operating condition setting device 3 (the same as in the prior art). (4) The parameters of the water quality model, such as the growth rate and decomposition rate, are set by the model parameter setting device 4 (same as the conventional technique). (5) The prediction interval is set by the prediction interval setting device 7. Set the simulation prediction interval to 1 minute. As a result of investigating the effect of the conventional prediction interval and simulation, it was found that the prediction interval is too short because the amount of organic matter is usually small and the amount of change in water quality is small. Here, the prediction interval is set longer than before. (6) The prediction calculation is performed by the simulation calculation device 5. Similar to the conventional technology, the water quality of the reaction tank and the quality of the treated water are predicted based on the output data of each device. The difference from the conventional technology is that the prediction interval of the simulation is subdivided based on the determination of the organic matter and the result. It is. (6a) An organic substance is determined. Organic matter change amount determination device 6
1, fermentation product (SA), fermentable biodegradable organic matter
It is determined whether or not the change amount of the prediction interval of the water quality such as (SF) exceeds the reference value. If it exceeds, the prediction interval subdivision device 71
Send the result to. If not, the process returns to the simulation calculation device 5 to perform the simulation of the next step. The fermentation product (S
A), It is determined whether or not the concentration of fermentable easily biodegradable organic matter (SF) has exceeded a reference value. If it exceeds, the result is transmitted to the prediction interval subdivision device 71. If not,
Returning to the simulation calculation device 5, the simulation of the next step is performed. (6b) Subdivide the prediction interval. Prediction interval subdivision device 71
When the information is received from the organic substance determination device 6, the simulation is performed by further dividing the prediction interval of the simulation. Here, the normal prediction interval of 1 minute was divided into 1/10, and the simulation calculation device 5 re-simulated. As a result of the re-simulation, when the amount of organic matter exceeds the reference value or the amount of change in water quality exceeds the reference value, the simulation is performed again by dividing it by 1/100. With this operation, the movement of the microorganism when the reaction is active can be calculated in detail, so that the simulation can be performed while maintaining the accuracy. As described above, the water quality simulation apparatus can detect the amount of organic matter, the amount of change in water quality, and the like, and set the prediction interval of the simulation. By adding the prediction interval subdivision device described above, the accuracy of the simulation can be maintained, and the prediction interval can be lengthened in the standard state (a state with little change), so that the simulation time can be shortened. (Second Embodiment) FIG. 2 shows a second embodiment of the present invention. FIG.
FIG. 3 is a block diagram of a configuration of a water quality simulation apparatus and a connection status with the periphery thereof. In the figure, 8 is a DO determination device,
Reference numeral 9 denotes a tank changing device, and the synthesizing device 91 and the dividing device 9
Consists of two. Next, the operation of the water quality simulation apparatus will be described. (1) The water quality measurement / analysis data is stored in the data storage device 1 (same as the conventional technology). (2) The treatment plant civil engineering structure is set by the treatment plant specification setting device 2 (same as the conventional technology). (3) The most suitable values for the treatment plant, such as the return rate, SRT, and DO concentration, are set by the operating condition setting device 3 (the same as in the prior art). (4) The parameters of the water quality model, such as the growth rate and decomposition rate, are set by the model parameter setting device 4 (same as the conventional technique). (5) Determine the DO concentration. The DO determination device 8 determines the DO concentration of each reaction tank, and transmits the result to the tank change device 6. (6) Determine tank change. When the DO is 0 mg / l or more, the tank synthesizing unit 61 of the tank changing device 6 issues a command to synthesize the tanks, and synthesizes a tank with a DO of 0 mg / l. DO is 0mg / l
In the above case, the tank performed almost the same reaction, and the DO was 0 mg / l
Since the same applies to the case of, such a combination is possible. The tank is divided by a tank dividing device 62 in order to see the reaction in the tank in detail, such as the front end or the rear end in the tank. (7) The prediction calculation is performed by the simulation calculation device 5 (same as the conventional technology). As described above, in the water quality simulation device, a tank whose reaction is considered to be the same can be synthesized by the tank change device, and the tank can be divided when a detailed reaction of the tank is desired. By adding such a device, the simulation process can be shortened because the reaction process is reduced. By using the simulation of the configuration obtained by adding the above-described first embodiment to the present embodiment, a great effect can be obtained in further shortening the simulation time and improving the accuracy.

[0010]

As described above, according to the present invention, a water quality simulation device for a sewage treatment plant is provided with an organic substance determination device including a prediction interval setting device, a concentration determination device, and a change amount determination device, and a prediction interval subdivision device. Since the water quality simulation can be divided according to the state of microorganisms,
Even if the prediction interval of the simulation is set to one minute, the accuracy of the simulation can be maintained, and the time of the entire simulation can be reduced. In addition, by combining a water quality simulation device with a DO detection device and a tank change device and synthesizing a tank, it took a long time to simulate a large number of tanks and many series of treatment plants, but the reaction process decreased. This has the effect of reducing the simulation time.

[Brief description of the drawings]

FIG. 1 is a block diagram of a water quality simulation apparatus showing a first embodiment of the present invention.

FIG. 2 is a block diagram of a water quality simulation apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a conventional water quality simulation device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 data storage device 7 prediction interval setting device 2 treatment plant specification setting device 71 prediction interval subdivision device 3 operating condition setting device 8 DO judgment device 4 model parameter setting device 9 tank changing device 5 simulation device 91 tank synthesis device 6 organic matter judgment device 92 Tank dividing device 61 Change amount judging device 10 First sedimentation tank 62 Concentration judging device 11 Reaction tank 12 Final sedimentation tank

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuya Hirabayashi 2-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu-shi, Fukuoka F-term (reference) 4D028 CC02 CC12 CE03 5B049 BB00 CC02 CC31 EE03 EE41

Claims (6)

[Claims] 1. A data storage device for storing water quality data of a sewage treatment plant comprising a first sedimentation site, a reaction tank, a final sedimentation site, etc., a treatment plant specification setting device for setting a treatment plant specification such as a civil engineering structure, and an operation An operating condition setting device for setting conditions;
A water quality simulation device comprising: a model parameter setting device for setting a water quality model parameter; and a simulation calculation device for receiving data from each of the devices and for predicting the water quality of the treatment plant for predicting the water quality of the treatment plant. A prediction interval setting device that changes a prediction interval between the simulation calculation device and an organic matter determination device that determines organic matter data such as a fermentation product and a fermentable biodegradable organic substrate from data of the data storage device. And a prediction interval subdivision device that further divides the prediction interval to perform a simulation when a value obtained by the organic substance determination device exceeds a reference value. 2. The water quality simulation device according to claim 1, wherein the organic matter determination device includes a change amount determination device that determines a change amount of water quality by the simulation calculation device. 3. The water quality simulation device according to claim 1, wherein the organic matter determination device includes a concentration determination device that determines a concentration of the organic matter. 4. A data storage device for storing water quality data of a sewage treatment plant comprising a first sedimentation site, a reaction tank, a final sedimentation site, etc., a treatment plant specification setting device for setting a treatment plant specification such as a civil engineering structure, and an operation An operating condition setting device for setting conditions;
A water quality simulation device comprising: a model parameter setting device for setting a water quality model parameter; and a simulation calculation device for receiving data from each of the devices and for predicting the water quality of the treatment plant for predicting the water quality of the treatment plant. A water quality simulation device comprising: a DO determination device that determines DO data of each of the reaction tanks; and a tank change device that changes a tank of the reaction tank between the simulation calculation device and the simulation calculation device. 5. The water quality simulation device according to claim 4, wherein the tank changing device comprises a tank synthesizing device for synthesizing a tank and a tank after checking a signal from the DO determination device. 6. The water quality simulation apparatus according to claim 4, wherein the tank changing device is a tank dividing device that divides and simulates the reaction tank.