KR20050009678A - Computing process apparatus for information on water quality - Google Patents

Abstract

PURPOSE: A device for processing water quality information operation of a water quality simulation is provided to offer a construction structure, an aeration condition, a measuring device, and an operation condition of a proper biological reactor reflecting a microbial model and satisfying a target processing water condition by defining a microorganism concentration and an inactive sludge concentration. CONSTITUTION: A simulator(20) comprises a data setting device(30), a microorganism concentration operation device(40), a model operation device(50), a data editing means(60), a coefficient setting device(65), an input/output device(70), and a database(90). The data setting device inputs data needed for simulation through a keyboard(71) or a mouse(72) and displays it to a monitor(73). An inflow condition setting means(31) sets a volume, the concentration, and a temperature of the inflow waste water. The construction structure setting means(32) sets an effective width/length/depth of the biological reactor and a final settling tank, and sets reactor division and pipeline of the biological reactor.

Description

Water quality information processing unit {COMPUTING PROCESS APPARATUS FOR INFORMATION ON WATER QUALITY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality information processing apparatus, and more particularly, to a water quality information processing apparatus suitable for simulating water quality in order to support the design and operation of an activated sludge process.

Sewage, such as sewage and plant drainage, is purified by a group of microorganisms called activated sludge, and this treatment is called an activated sludge process. The currently operated sewage treatment plant is mainly activated sludge process, and employs a standard activated sludge method whose main purpose is to remove organic matter. In the standard activated sludge method, organic matter in the influent sewage is ingested or oxidatively decomposed into activated sludge in a biological reactor, and the supernatant is discharged by sedimenting activated sludge in the final settling basin installed in the rear stage.

In recent years, the introduction of advanced treatment systems for removing these nutrients from sewage treatment plants is being regulated under the total amount of nitrogen and phosphorus in closed waters. Advanced treatment methods for removing nitrogen and phosphorus from sewage are largely divided into physicochemical and biological methods. Biological methods are being introduced into sewage treatment plants because they can be constructed by adapting existing standard activated sludge methods. Since the standard activated sludge method supplies air to the entire biological reactor, the biological reactor is always in an aerobic state in which dissolved oxygen is present. On the other hand, advanced sewage treatment using biological nitrogen and phosphorus removal mechanisms is a method of realizing phosphorus removal and nitrogen removal in combination with an aerobic state by creating an anaerobic state in which dissolved oxygen does not exist in a biological reactor.

Biological nitrogen removal consists of a nitrogenization process in an aerobic state and a denitrification process in an anoxic state. Generally, the bacterium that carries out the nitrification reaction is called nitrifying bacteria or autotrophic bacterium (hereinafter referred to as autotrophic bacterium), and the bacterium which performs denitrification reaction is referred to as denitrifying bacterium or other nutrient bacterium (hereinafter referred to as taconutrient) have. Biological removal is a treatment method that removes phosphorus from sewage using an anaerobic phosphorus release process and an aerobic phosphorus excess intake process. Thus, the bacteria which have the ability to ingest excess phosphorus are generally called phosphorus accumulation bacteria.

Such advanced sewage treatment is performed by appropriately maintaining the reproductive environment of other nutrients, autotrophs, and phosphorus accumulators related to organic matter, nitrogen, and phosphorus removal. In addition, the reproductive environment of various microorganisms in activated sludge is greatly dependent on the inflow conditions and operating conditions, and the design and maintenance of the treatment facility is more complicated than the standard activated sludge method.

However, until now, there is no way to calculate and present the complex reaction process of organic matter, nitrogen and phosphorus, and the design and operation of the sewage advanced treatment have depended on experience and sense. As a result, an unpredictable situation arises regarding influent sewage quality and quantity, biological reactor composition, and operating conditions that have not been experienced, and there is a problem in that measures are taken every time.

On the other hand, a method of modeling a biological reaction and evaluating the characteristics of the activated sludge process by numerical simulation has been proposed. As an example of the model of the biological reaction, the activated sludge model ASM No. 1 (1986), No. 2 (1995), No. 2d (1998), No. 3 (1999) published by the International Water Association (IWA) abroad. Is proposed. Currently, activated sludge models No. 2 (hereinafter referred to as ASM-No. 2) and No. 2d (hereinafter referred to as ASM-No. 2d) are most commonly used as nitrogen and phosphorus removal models. However, these activated sludge models are structures in which biological reactions are mathematically described and do not provide simulation soft wafers. Moreover, the method of calculating water quality by the sewage treatment process simulator using a biological model is proposed like Unexamined-Japanese-Patent No. 2000-167585 and 2002-1370.

[Patent Document 1]

Japanese Patent Publication No. 2000-167585

[Patent Document 2]

Japanese Patent Publication No. 2002-1370

Among the prior art, activated sludge models ASM-No.2 and ASM-No.2d published by the International Water Association (IWA) show reaction processes such as nitrification, denitrification, phosphorus release, phosphorus intake, organic matter decomposition, cell growth and autolysis. The reaction rate of is calculated by the concentrations of other nutrients, autotrophs, and phosphorus accumulation bacteria, respectively. Therefore, in order to accurately calculate the reaction rate of the above reaction process, it is necessary to grasp the concentrations of other nutrients, autotrophs, and phosphorus accumulating bacteria in activated sludge. In the activated sludge model of the International Water Association, the concentrations of other nutrients, autotrophs, and phosphorus accumulators are expressed using COD (chemical oxygen demand; CODcr), respiration rate, or reaction rate by potassium dichromate. The unit is gCOD / m 3. However, in order to measure the respiratory rate and reaction rate, not only special devices and techniques are required, but also various pretreatments for suppressing other reactions are required, and thus there is a problem that cannot be easily performed in the treatment plant. In addition, said pretreatment is the process of suppressing a nitrification reaction, for example, when measuring the respiration rate of a nutrient.

On the other hand, daily sludge management in a sewage treatment plant is performed by the sludge concentration (MLSS) (unit: mg / L) in a reaction tank. The reason is that the MLSS can be easily obtained by manual analysis or an automatic measuring instrument. Manual analysis of MLSS is routinely performed because it is a simple method of filtering a mixed solution of a reaction tank with a filter paper, drying the solid material remaining on the filter paper, and measuring the weight of the solid material. In addition, many processing plants perform continuous measurement by the MLSS system with the improvement of the performance of the MLSS automatic measuring instrument. In sewage treatment plants, for example, management indicators such as SRT (solid retention time; unit: day), A-SRT (aerobic solids retention time; unit: day), SVI (sludge capacity indicator; unit: ml / gSS) All are based on MLSS. In addition, SRT means the average residence time until activated sludge is removed as excess sludge, and SVI is represented by the number of ml of capacity occupied by 1 g of sludge based on SV30 (sludge capacity: unit:%). Say what you did. Said SV30 [%] represents the amount of sludge settled after putting the liquid mixture in a biological reaction tank into the 1 liter measuring cylinder, and standing still for 30 minutes. The sludge settling situation in the final settling basin is controlled by SV30, or SVI. The larger the SVI, the worse the sludge settling, and the non-settling sludge flows out of the machine along with the treated water. SVI is an important indicator and its definition is shown in Equation 1.

[Equation 1]

SVI [ml / gSS] = SV30 [%] × 0.01 × 1000 [ml] / (MLSS [mg / L] × 1 [L] × 0.001)

However, if the concentrations of other nutrients, autotrophs, and phosphorus accumulators are expressed as gCOD / ㎥, as in the activated sludge model of the International Water Association, MLSS [mg / L] cannot be calculated. For example, SVI cannot be presented for calculation.

In addition, at low water temperature, in order to increase the holding time of the autotrophic bacteria in the system, it is necessary to increase the A-SRT, and to do so, it is necessary to increase the MLSS. On the other hand, if the MLSS is increased, the amount of air is increased, so it is desirable to keep it low from the viewpoint of energy saving. To properly manage these conflicting conditions, it is necessary to find the lowest MLSS that can maintain the A-SRT. In addition, MLSS is used not only for the maintenance of the treatment process but also as a design factor of the reaction tank capacity. As such, for activated sludge processes, MLSS is an essential indicator. As described above, although it is very important to express activated sludge in MLSS, there is a problem that cannot be expressed in the activated sludge model of the International Water Association.

In addition, in the conventional sewage treatment simulator, MLSS cannot be expressed in order to treat microbial concentration as gCOD / m 3 as in the activated sludge model of the International Water Association, and the above problems cannot be solved.

Thus, an object of the present invention is to overcome the problems of the prior art, to define the microbial concentration and inert solids concentration in the sludge based on MLSS to reflect in the biological model, civil structure of a suitable biological reaction tank to satisfy the target treated water conditions, To support aeration, instrumentation and operating conditions.

1 is a block diagram showing one embodiment of a simulation system of an activated sludge process of the present invention.

Figure 2 is an embodiment showing a means for calculating the autotrophic bacteria concentration of the present invention.

3 is an embodiment showing a means for calculating the phosphorus accumulating bacteria concentration of the present invention.

4 illustrates an embodiment representing means for computing a biological model of the present invention.

5 is a flowchart showing a simulation procedure according to an embodiment of the present invention.

6 is a screen example for setting the MLSS of the present invention.

Fig. 7 is a screen example showing a coefficient setting device of the present invention.

8 is an embodiment showing the sludge settling velocity of the present invention.

9 is an example showing the calculation result of the sludge concentration according to the present invention.

10 is an example showing the calculation result of the sludge mass according to the present invention.

11 is an embodiment showing maintenance according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: biological reactor

2: final sedimentation basin

3: influent

4: conveying pump

5: conveying sludge pipe

6: surplus pump

7: surplus sludge pipe

8: circulation pump

9: circulating sludge pipe

10: discharge pipe

11: blower

12: pipeline

13: air blower

14: on-off valve

16: dissolved oxygen concentration (DO) system

17: MLSS system

20: simulator

30: data setting device

31: inflow condition setting means

32: civil structure setting means

33: operating condition setting means

34: MLSS initial value setting means

35: inert solid concentration setting means

36: SVI setting means

40: microbial concentration calculation device

41: microbial concentration calculation means

42: means for calculating autotrophic concentration

43: means for calculating the concentration of phosphorus accumulator

44: means for calculating taga nutrient concentration

50: model computing device

51: biological model calculation means

52: transportation model calculation means

53: dissolved oxygen model calculation means

60: data editing means

65: coefficient setting device

70: input / output device

71: keyboard

72: mouse

73: monitor

80 plant input means

90: database

In order to achieve the above object, the present invention is configured to have a means for inputting the sludge concentration information in the reaction tank, and a means for calculating the microbial concentration information and inert solid concentration information based on the sludge concentration information.

Or, it is a simulation system of an activated sludge process that performs water quality simulation in order to support the design and operation of an activated sludge process, and includes inflow condition setting means for setting the quantity and quality of the influent, the size of the treatment process and the division of the biological reactor. Calculating civil structure setting means to set, means for setting MLSS, means for setting the inert solid concentration in the MLSS, means for calculating the microbial concentration from the MLSS and the inert solid concentration, and autotrophic bacteria concentration in the MLSS. Means for calculating the concentration of phosphorus accumulating bacteria in the MLSS, means for calculating the value of other nutrients in the MLSS, operating condition setting means for the treatment process, and SVI setting means for inputting the sludge settling index of the final settling basin; The water quality and sludge concentrations of the bioreactor, the final settling basin and the returned sludge A model calculating means, a database for storing the water quality data and the sludge concentration calculated by the model calculating means, data editing means for extracting the water quality data and the sludge concentration from the database, and data display means. It features.

Further, the microbial concentration calculating means is characterized by having a means for calculating the microbial concentration on the basis of the difference between the MLSS and the inert solid concentration.

In addition, the autotrophic bacteria concentration calculating means is characterized by having a means for calculating the autotrophic bacteria concentration using the A-SRT.

The phosphorus accumulation bacterium concentration calculating means has a means for calculating the phosphorus accumulation bacterium concentration using the phosphorus concentration in the MLSS, the phosphorus concentration in the inert solids, and the phosphorus concentration in the microorganism.

In addition, the means for calculating the value of the nutrient concentration of the nutrient is characterized in that it has a means for calculating the value of the nutrient value on the basis of the difference between the concentration of microorganisms, the concentration of autotrophic bacteria and the concentration of phosphorus accumulation bacteria.

The model calculating means is characterized by having a biological model calculating means for calculating a biological reaction, a transport model calculating means for calculating a fluid, and a dissolved oxygen model calculating means for calculating the dissolved oxygen supply capability of the aeration device.

In addition, the biological model calculation means is characterized in that it has a means for calculating the time change of the MLSS.

The transport model calculation means may include means for expressing the sludge settling velocity of the final settling basin using the SVI set as the SVI setting means, and means for calculating the conveyed sludge concentration and the excess sludge concentration.

Further, the data editing means is a reaction tank sludge mass, conveyed sludge mass, excess sludge mass per unit time by using the MLSS calculated by the biological model calculating means and the conveyed sludge concentration and the excess sludge concentration calculated by the transport model calculating means. And means for calculating SRT.

In reference to the effects of the above constitution, the suspended solids in the mixed solution consist of microorganisms that perform bioreaction and inert solids that do not participate in the bioreaction. Therefore, by using the MLSS representing the active sludge concentration of the reaction tank, it is possible to calculate the treated water quality by defining the concentrations of other nutrients, autotrophs, and phosphorus accumulators, as well as the MLSS, the return sludge concentration and the excess sludge concentration after the reaction. It can be calculated. In addition, the conveyed sludge mass and the excess sludge mass per unit time can be calculated using the conveyed sludge concentration and the excess sludge concentration. In addition, SRT or A-SRT can be calculated using MLSS, reactor volume and excess sludge mass per unit time.

In addition, it is possible to support the maintenance of the process by presenting MLSS that can satisfy the treated water quality when the inflow quantity, inflow water quality, season, and operating conditions change.

As described above, not only the water quality of the effluent is calculated as in the prior art, but also the MLSS is calculated as in the present invention, so that the matching of civil, mechanical, instrumentation, and sludge conditions can be presented, and the removal performance of contaminants can be improved. It is possible to easily perform the optimum design and the optimum operation.

1 is an embodiment in which the present invention is applied to the simulation of an activated sludge process.

In Fig. 1, three anaerobic tanks 1 of anaerobic tank 1a, anoxic tank 1b, and aerobic tank 1c and an anaerobic-oxygen-aerobic method circulating from an aerobic tank 1c to anoxic tank 1b will be described. . Inflow sewage is sedimentary (not shown) from the sediment, sediment, dust and large solids after sedimentation, and then enters the initial settling (not shown). In the initial settling basin, the solids are sedimented and removed, and the supernatant liquid containing organic matter, ammonia nitrogen, phosphorus, etc. is transferred as the inflow water 3 into the bioreactor 1. The inflow water 3 from the initial settling basin and the conveying sludge (active sludge) from the conveying sludge tube 5 are introduced into the bioreactor 1 and stirring and mixing are performed. On the other hand, air is blown into the bioreactor 1 from the blower 11 via the air supply pipe 12 and the air supply device 13. In the biological reaction tank 1, the sludge is circulated from the aerobic tank 1c to the anoxic tank 1b via the circulation sludge pipe 9 by the circulation pump 8. Here, in the anaerobic tank 1a, dissolved oxygen (DO) and nitrogen nitrate (NO ₃ ) do not exist together, and the phosphorus (PO ₄ -P) release reaction proceeds.

In the anaerobic tank 1a, activated sludge hydrolyzes phosphorus stored in the body and releases it into sewage. At the same time, activated sludge adsorbs organic matter and is stored in cells. By this biological reaction, phosphorus is increased in the anaerobic tank 1a and organic matter is reduced.

The anaerobic tank 1b flows in the mixed water of the sewage and conveyed sludge which flowed out from the anaerobic tank 1a, and the circulating water from the aerobic tank 1c, and is stirred and mixed in a mechanical stirring facility (not shown). In the oxygen-free tank 1b, nitrogen nitrate (NO ₃ ) is circulated from the aerobic tank 1c, and the environment is free of dissolved oxygen. Nitrogen nitrate is reduced and released into the atmosphere as nitrogen gas (N ₂ ). This is called denitrification.

At the bottom of the exhalation tank 1c, an air feeding device (the above device) 13 is provided, and the air blown from the blower 11 through the air supply pipe (air pipe) 12 is the air feeding device (aerator device) 13 Is aerated, and the oxygen is supplied while stirring the mixed liquid consisting of sewage and activated sludge in the aeration tank 1c. The opening / closing valve 14 provided in the air supply pipe (air pipe) 12 adjusts the air volume to the exhalation tank. The blower 11 is operated by a control system for blowing the air volume set in advance, or a control system for blowing air so that the value of the dissolved oxygen concentration (DO) system 16 installed in the aerobic tank 1c is maintained at a predetermined value. The fouling substance of the mixed liquid in the aerobic tank 1c is processed by the action of activated sludge activated by oxygen supply. For example, activated sludge adsorbs organic matter and absorbs oxygen in the supplied air to oxidize and decompose organic matter to carbon dioxide gas and water. In addition, phosphorus is stored in the cells in activated sludge under aerobic conditions and consumed more than released from the anaerobic tank 1a to reduce the concentration in the influent sewage. In addition, ammonia nitrogen is oxidized to nitrate nitrogen. These are called nitrogenization reactions. In addition, some of contaminants such as organic matter, phosphorus and ammonia nitrogen are used for the growth of activated sludge. The MLSS system 17 is used for sludge management by measuring the concentration of the mixed liquid in the biological reaction tank.

Such treated water after the biological reaction is led to the final settling basin 2. In the final sedimentation basin (2), the activated sludge is gravity sedimented to chlorine sterilize the supernatant and then discharged by the discharge pipe (10). A part of the settling sludge of the final settling basin 2 is transferred to the bioreactor 1 by the conveying sludge tube 5 by the conveying pump 4, and the remaining sludge is surplus sludge tube 7 by the surplus pump 6. Is discharged out of the system. The conveying pump 4 is operated by control of the amount of conveying sludge or control of the ratio of the amount of conveyed sludge and the amount of inflow sewage. The circulation pump 8 is operated by control of the amount of circulating liquid or control of the ratio of the amount of circulating liquid and the amount of inflow sewage. The surplus pump 6 is operated by control of the amount of excess sludge or control of the amount of excess flow and inflow of sewage.

The configuration of the simulator 20 for the anaerobic-anaerobic-expiration method described above will be described with reference to FIG. 1.

The simulator 20 includes a data setting device 30 and a microbial concentration calculating device 40 (wherein microbial concentration information indicates information substantially equivalent to microbial concentration, including microbial concentration), and model calculation. The apparatus 50 is comprised from the apparatus 50, the data editing means 60, the coefficient setting apparatus 65, the input / output apparatus 70, and the database 90. As shown in FIG. Here, the example applied to the design of a plant is demonstrated. The data setting device 30 inputs data necessary for the simulation by using the keyboard 71 or the mouse 72 to be displayed on the monitor 73. The inflow condition setting means 31 sets the inflow effluent amount, the concentration of the inflow water quality, and the water temperature. Here, the water quality is, for example, organic matter (reversely decomposable and hardly decomposable), ammonia nitrogen, total nitrogen, phosphorus, suspended solids concentration, alkalinity, dissolved oxygen, nitrogen nitrate, and the like. The data may be 24-hour actual data of the plant input by the plant input means 80, may be 24-hour data created by a daily average value and a 24-hour variation pattern, or may be constant through 24 hours. The civil engineering structure setting means 32 sets the dimensional data of the effective width, the effective length and the effective depth of the biological reaction tank and the final settling basin, the coarse division setting of the biological reaction tank, and the pipe setting. Said piping setting sets the installation situation of the circulation sludge pipe 9, the air supply pipe (air pipe) 12, and the conveying sludge pipe 5 of this embodiment, for example. The operating condition setting means 33 includes the amount of blowing air from the blower 11 to the biological reaction tank 1, the amount of circulating sludge from the aerobic tank 1c to the anoxic tank 1b, the amount of conveyed sludge from the settling basin 2 to the anaerobic tank 1a, and the surplus Set operating conditions such as sludge amount.

The MLSS initial value setting means 34 sets the bioreactor MLSS measured by manual analysis or MLSS system (wherein sludge concentration information indicates information substantially equivalent to sludge concentration, including sludge concentration). .

The inert solid concentration setting means 35 sets the inert solid concentration which does not participate in the biological reaction in the MLSS (wherein the inert solid concentration information is substantially equivalent to the inert solid concentration, including the inert solid concentration). Information). In a conventional activated sludge process, this inert solid is mainly a product of inorganic matter in the influent and microorganism self-decomposition, but in the case of an activated sludge process in which chemicals such as a flocculant are added, salts generated by a chemical reaction also become an inert solid. . Since it is known that about 10% of inert solids are produced during the self-decomposition of microorganisms, the concentration of the inert solids may be defined with reference to this, or the results obtained from the analysis and experiment of real data may be set. As an example of the inert solid concentration setting means 35, an example of calculating the inert solid concentration in a process in which a flocculant (for example, aluminum sulfate, PAC) containing aluminum is added to Equation 2 is shown.

[Equation 2]

Inert Solid Concentration [mg / L]

= FAl [gAl / gSS] × fss_Al [gSS / gAl] × MLSS [mg / L]

However, fAl: Al content per SS, fss_Al: solids generated per Al

Al content per SS (solid amount of sludge solids) may refer to a sludge analysis value, and may be set to the analytical curve obtained from the injection rate of a flocculant. The amount of solids generated per Al (fss_Al) varies depending on the type of flocculant, and may be referred to a literature value, or may be an actual value obtained in an experiment. In addition, flocculants generally used in sewage treatment plants include aluminum (Al) and iron (Fe) salts. Although the example using the coagulant containing aluminum (Al) was shown in the Example of Formula 2, it can be set similarly also when using a coagulant containing iron, such as a ferrous sulfate solution and a ferric chloride solution.

The SVI setting means 36 sets the SVI measured by manual analysis.

The simulation condition set by such a data setting apparatus 30 is stored in the database 90. In addition, the setting contents are displayed on the monitor 73 by graphics or the like.

The microbial concentration calculating device 40 is based on the simulation conditions of the database 90, microbial concentration calculating means 41, autotrophic bacterium concentration calculating means 42, phosphorus accumulation bacterium concentration calculating means 43 and The initial value of the concentration of the microorganisms involved in the biological reaction is calculated by using the tagase nutrient concentration calculating means 44, and the result is stored in the database 90.

The microbial concentration calculating means 41 performs microbial concentration setting for performing a biological reaction in the MLSS using the MLSS set by the MLSS initial value setting means 34 and the inert solid concentration set by the inert solid concentration setting means 35. The microbial concentration can be obtained by equation (3).

[Equation 3]

Microbial Concentration [mg / L] = MLSS [mg / L] -Inert Solid Concentration [mg / L]

The autotrophic bacterium concentration calculating means 42 calculates the autotrophic bacterium concentration in Formula 4 using the microbial concentration obtained in Formula 3, for example.

[Equation 4]

Autotrophic Concentration [mg / L]

= (A-SRT results / θ _XA ) × ø [gSS / gSS] × microbial concentration [mg / L]

Ø: maximum autotrophic amount of microbial sugar [gSS / gSS]

θ _XA : A-SRT [day] required for nitrogenization

In addition, the A-SRT required for the nitrification of self-nutrient bacteria θ _XA is well calculated in Equation 5 based on the sewerage facilities planning and design guidelines, it may be determined experimentally.

[Equation 5]

θ _XA = δ × 20.6 × exp (-0.0627 × T)

Where T is the water temperature [° C]

δ: correction factor for fluctuations in influent T-N

Next, the operational flow of the autotrophic bacterium concentration calculating means 42 will be described with reference to FIG.

2 is an embodiment of the operational flow of the autotrophic bacteria concentration calculating means 42. In step S1, A-SRT required for nitrification is calculated using the water temperature set by the inflow condition setting means 31 and Formula 5. In step S2, the A-SRT is based on the MLSS obtained by the MLSS initial value setting means 34, the reaction tank volume obtained by the civil engineering structure setting means 32, and the amount of excess sludge obtained by the operating condition setting means 33. Calculate the performance value of. In step S3, the autotrophic bacteria concentration is calculated in Equation 4 using the microbial concentration obtained in Equation 3, the A-SRT required for the nitrification obtained in Step S1, and the A-SRT results obtained in Step S2.

1, the phosphorus accumulating bacteria concentration calculating means 43 will be described.

Phosphorus accumulator concentration calculating means 43 sets the phosphorus accumulator concentration using the phosphorus concentration contained in MLSS, the inert solid concentration obtained by Equation 2, and the microbial concentration obtained by Equation 3, for example. To calculate. An example is shown in Formula 6.

[Equation 6]

Phosphorus accumulation bacterium concentration [mg / L]

= (Sp [mgP / L] -Bp [mgP / L] -Ip [mgP / L]) / fpp [gP / gSS]

However, fpp: Polyphosphoric acid content of phosphorus accumulating bacteria [gP / gSS]

In addition, in Formula 6, Sp, Bp, and Ip can be defined by Formula 7, Formula 8, and Formula 9, respectively.

[Equation 7]

Sp [mgP / L] = MLSS [mg / L] × fsp [gP / gSS]

[Equation 8]

Bp [mgP / L] = microbial concentration [mg / L] × fxp [gP / gSS]

[Equation 9]

Ip [mgP / L] = inert solid concentration [mg / L] × fip [gP / gSS]

However, fsp: P content per MLSS

fxp: P content of microbial sugar

fip: P content per inert solid

fsp, fxp, fip and fpp may refer to a literature value, and may use the experience value acquired by experiment. Of course, their values differ depending on the activated sludge process.

32, the calculation flow of the phosphorus accumulation bacterium concentration calculating means 43 will be described.

3 is a diagram showing one embodiment of the calculation flow of the phosphorus accumulation bacterium concentration calculating means 43. As shown in FIG. In step S11, the phosphorus concentration contained in MLSS is calculated by Equation 7 using the MLSS obtained by the MLSS initial value setting means 34. In step S12, the phosphorus concentration contained in the microorganism is calculated in Equation 8 using the microorganism concentration obtained in Equation 3. In step S13, the phosphorus concentration contained in an inert solid is calculated by Formula 9 using the inert solid concentration obtained in Formula 2. In step S14, the phosphorus accumulation bacteria are made using the phosphorus concentration contained in the MLSS obtained in step S11, the phosphorus concentration contained in the microorganism obtained in step S12, and the phosphorus concentration contained in the inert solid obtained in step S13. The concentration is calculated in Equation 6.

Here, returning to FIG. 1 again, the tagase nutrient concentration calculating means 44 will be described.

The taga nutrient concentration calculating means 44 of FIG. 1 is, for example, using a microorganism concentration obtained in Equation 3, an autotrophic bacterium concentration obtained in Equation 4, and a phosphorus accumulation bacterium concentration obtained in Equation 6, for example. Calculate nutrient concentrations. An example is shown in Formula 10.

[Equation 10]

Taga nutrient concentration [mg / L] = microorganism concentration [mg / L]

-Autotrophic bacteria concentration [mg / L]-phosphorus accumulation bacteria concentration [mg / L]

In this way, the simulation conditions calculated from the microorganism concentration calculation device 40 are stored in the database 90. The content of the calculation is displayed on the monitor 73 by a graphic or the like.

The model calculation device 50 uses the biological model calculation means 51, the transport model calculation means 52, and the dissolved oxygen model calculation means 53 based on the simulation conditions of the database 90. The water quality, sludge concentration and flow rate of the final settling basin, return sludge and excess sludge are calculated and the results are stored in the database 90.

The biological model calculating means 51 calculates the water quality and the MLSS which are changed by the biological reaction model. Known models such as ASM-No. 2 and ASM-No. 2d published by the International Water Association may be applied to these biological reaction models, or models created from chemical reaction equations or models obtained experimentally may be applied. Here, the reaction rate of the multivalent nutrient growth of ASM-No. 2 is shown in equation (11).

[1]

However, S ₀₂ : dissolved oxygen [gO ₂ / m], S _F : easily decomposed organic substance [gCOD / ㎥], S _A : fermentation product (acetic acid) [gCOD / ㎥], S _NH4 : ammonia nitrogen [gN / ㎥], S _NO3 : Nitrogen Nitrate [gN / ㎥], S _PO4 : Soluble Phosphorus [gP / ㎥], S _ALK : Alkalinity [gCOD / ㎥], X _H : Taga nutrient [gCOD / ㎥], μ _H : maximum growth rate [1 / d], K _O2 : S _O2 saturation coefficient [gO ₂ / ㎥], K _F : S _F saturation coefficient [gCOD / ㎥], K _NH4 : S _NH4 saturation coefficient [gN / ㎥], K _PO4 : Saturation coefficient of S _PO4 [gP / ㎥], K _ALK : Saturation coefficient of S _ALK [gCOD / ㎥]

As described in the present invention, the activated sludge model of the International Water Association treats microbial concentrations as gCOD / m 3. Thus, for example, the value of the value of the nutrients [mg / L] obtained in Eq. In state, it is not applicable to Xh of Equation 11.

Next, an embodiment of the biological model calculating means 51 of the present invention will be described with reference to FIG. 4 shows an example in which the microbial concentration [mg / L] of the present invention is applied to ASM-No. In step S21, the autotrophic bacterium concentration [mg / L] obtained in Equation 4, the phosphorus accumulation bacterium concentration [mg / L] obtained in Equation 6, and the value of the other nutrient concentration [mg / L] obtained in Equation 10 are determined. The unit is converted from mg / L to gCOD / m 3. An example of converting the unit of mg / L into gCOD / m 3 is shown in Equation 12.

[Equation 12]

S _M [gCOD / m 3] = S [mg / L] × θ [gCOD / g]

Where S _M , S: microbial concentration, and

In addition, the unit conversion value (theta) changes with microorganisms, may refer to a literature value, and may use each experimental data.

In step 22, the water value and microbial concentrations were obtained by applying the value of taga nutrients [gCOD / ㎥], autologous bacteria concentration [gCOD / ㎥], and phosphorus accumulation bacteria [gCOD / ㎥] obtained in step 21 to ASM-No.2. Calculate the change in the concentration of degradable solids in gCOD / m 3. The above-mentioned degradable solids are solid materials produced upon self-decomposition of microorganisms.

In step 23, the unit of the post-reacting value of other nutrients [gCOD / m], the autotrophic concentration after the reaction, the phosphorus accumulation concentration after the reaction, and the degradable solids concentration after the reaction are determined from gCOD / m3. Convert to mg / L. An example of converting a unit of gCOD / m 3 to mg / L is shown in Equation 13.

[Equation 13]

S [mg / L] = S _M [gCOD / m 3] / θ [gCOD / g]

In step 24, the post-reaction value tagase nutrient concentration [mg / L], the autotrophic bacteria concentration [mg / L] after the reaction, the phosphorus accumulation bacterium concentration [mg / L] after the reaction, and the full amount after the reaction MLSS after the reaction is calculated from Equation 14 using the dissolved solids concentration [mg / L].

[Equation 14]

MLSS [mg / L] after the reaction = value of the value of the value of the value of the value of the value of the nutrient value [mg / L] after the reaction

+ Autotrophic bacteria concentration [mg / L] after reaction

+ Phosphorus accumulation bacterium concentration after reaction [mg / L]

+ Degradable solid concentration after reaction [mg / L]

+ Concentration of inert solid material before the reaction [mg / L]

In this way, the concentration change of the MLSS can be calculated by the biological model calculating means 51. In addition, the biological model calculation means 51 can be applied not only to the biological reaction tank but also to the final settling basin, whereby the sludge concentration change of the final settling basin due to the biological reaction can be calculated.

Here, the transportation model calculation means 52 will be described again with reference to FIG.

The transport model calculation means 52 of FIG. 1 calculates the varying water quality and sludge concentration on the basis of the fluid of the inflow sewage amount, the conveyed sludge amount, the excess sludge amount, and the circulating sludge amount. In the final settling basin, the sludge sedimentation rate is expressed using the SVI obtained by the microbial concentration calculating device (SVI setting means) 40, and the change in the sludge concentration of the sedimented sludge is calculated.

The dissolved oxygen model calculating means 53 calculates the dissolved oxygen supplied to the aerobic tank 1c from the blowing amount, for example, using the concept of the overall oxygen transfer capacity coefficient.

The calculation results of these model computing devices 50 are stored in the database 90.

The coefficient setting device 65 inputs, for example, the coefficient data required for the microbial concentration calculation device 40 and the coefficient data required for the biological model calculation means 51 using the keyboard 71 or the mouse 72. Is displayed on the monitor 73. The coefficient data required for the above-mentioned microorganism concentration calculation device 40 is, for example, fss_Al in Expression 2, fpp in Expression 6, and the like, and the coefficient data required for the biological model calculating means 51 is, for example, in Expression 11; μ _H , K _O2 , K _NH1 and the like.

The data editing means 60 edits the data stored in the database 90 in the form of a bar graph, a trend graph, a calculation result list, a removal rate, a material balance, and the like, and outputs the data to the monitor 73.

Next, Fig. 5 is a flowchart of one embodiment showing the operation of the simulation of the present invention. In step S31, the inflow condition setting means 31 sets the inflow quantity, inflow water quality (organic matter, ammonia nitrogen, phosphorus, SS, alkalinity, etc.) and the water temperature. In step S32, the civil engineering structure setting means 32 performs the dimensions of the biological reaction tank and the final settling basin, rough division of the biological reaction tank, and pipe setting. In step S33, the operation condition setting means 33 controls the blower 11's control conditions (air flow amount, DO target), the control conditions of the transfer pump 4 (conveyance sludge amount, target value of transfer rate, timer drawing), surplus pump ( 6) control conditions (amount of excess sludge, target value of surplus rate, timer drawing) and control conditions (circulation sludge amount, target value of circulation rate) of the circulation pump 8 are set. In step S34, the MLSS initial value setting means 34 sets the initial value of the MLSS. In step S35, the inert solid concentration is set using Equation 2. In step S36, the SVI setting means 36 sets the SVI. In step S37, the initial value of the microorganism concentration is set using Equation 3. In step S38, the autotrophic bacteria concentration initial value is calculated using Equation 4. In step S39, phosphorus accumulation bacterium concentration initial value is computed using Formula (6). In step S40, the value of the other nutrient bacterium concentration initial value is set using Equation 10. In step S41, the units of the autotrophic bacterium concentration, the phosphorus accumulation bacterium concentration, and the tagalife bacterium concentration set in steps 37, 38, and 39 are converted from mg / L to gCOD / m 3 according to the equation (12).

Based on the above condition setting, a simulation is performed in step S42, and organic substance and nitrogen; Calculate the concentration of phosphorus, microorganisms, and degradable solids. In step S43, among the calculation results of step S42, the unit of autotrophic bacteria concentration, phosphorus accumulation bacterium concentration, tagalife bacteria concentration, and degradable solids concentration is converted from gCOD / m 3 to mg / L by equation (13). In step S44, the change of MLSS, conveyed sludge concentration, and excess sludge concentration is calculated using Formula 14.

6 shows an example of the setting screen of steps S34, S35, S36 of the embodiment of FIG.

7 shows an embodiment of the coefficient setting device 65. 7 shows an example of a screen for setting coefficient data required for calculation of the phosphorus accumulation bacterium concentration in equation (6). In Example Step 39 of FIG. 5, the phosphorus accumulation bacterium concentration is calculated by Equation 6 using the coefficient data of Example FIG.

Fig. 8 shows an embodiment showing the sludge settling rate of the final settling basin using the SVI input from the microbial concentration calculating device (SVI setting means) 40. The smaller the SVI, the larger the sedimentation rate of the sludge. On the contrary, the larger the SVI, the smaller the sedimentation rate of the sludge. As such, by expressing the sedimentation rate of the sludge using SVI, the sludge concentration of the sedimentation sludge of the final settling basin can be expressed, and the return sludge concentration and the excess sludge concentration can be calculated.

FIG. 9 shows an embodiment of a 24h trend graph of conveyed sludge concentration calculated in the embodiment step 44 of FIG. As such, the sludge concentration (including microorganisms and inert solids) that is constantly changing can be calculated.

10 shows an embodiment of the data editing means 60. As shown in FIG. FIG. 10 shows an example in which the sludge mass per unit time is calculated using the reactor effluent MLSS, the return sludge concentration and the excess sludge concentration obtained in the example of FIG. 5. The sludge mass per unit time is obtained by equation (15).

[Equation 15]

Sludge Mass [kg / h] = Sludge Concentration [mg / L] × Flow Rate [㎥ / h]

In addition, although the sludge mass per 1h was shown in the Example of Formula 15, the sludge mass per day can also be calculated similarly. As shown in the example of Fig. 10, in the bioreactor and the final sedimentation basin, the respective sludge resins can be taken to calculate the SRT and A-SRT, and maintenance by SRT and A-SRT becomes possible. In addition, SRT is obtained by equation (16).

[Equation 16]

SRT [day] = (MLSS [mg / L] × reactor volume [m 3])

÷ (Excess sludge concentration [mg / L] × surplus [㎥ / h] × 24 [h / day])

11 shows an embodiment of maintenance according to the present invention. Fig. 11 shows an example of the result of simulation by reducing the amount of excess sludge. Reducing the amount of excess sludge increases the MLSS with elapsed time, and the effluent T-N decreases with increasing MLSS. Fig. 11 shows an example in which the discharged water T-N can satisfy 10 mg / L when tSS reaches 300 mg / L after t hours. The maintenance according to the present invention manipulates the amount of excess sludge to maintain MLSS in the reaction vessel at 2300 mg / L based on the result of FIG. 11, for example. As such, when the inflow amount, the inflow water quality, the operating conditions or the water temperature change, an MLSS that can satisfy the treated water quality as shown in FIG. 11 may be proposed and reflected in the maintenance of the treatment process.

The above simulations can be carried out by changing the civil engineering structure, instrumentation equipment, sludge specifications, and operating conditions of the process to understand the water quality and sludge variations in the process. As a result, it is possible to easily grasp where the civil structure and the operating conditions are to be improved in order for the entire process to achieve the optimum removal performance.

Thus, not only can the treated water quality be calculated, but also the MLSS, the conveyed sludge concentration and the excess sludge concentration after the reaction can be calculated. In addition, the conveyed sludge mass and the excess sludge mass per unit time can be calculated using the conveyed sludge concentration and the excess sludge concentration. In addition, SRT or A-SRT can be calculated using MLSS, reactor volume and excess sludge mass per unit time. In addition, it is possible to support the maintenance of the process by presenting MLSS that can satisfy the treated water quality when the inflow quantity, inflow water quality, season, and operating conditions change.

Therefore, the optimization of the sludge concentration conditions and operation can be achieved by suggesting the matching of civil machinery, instrumentation, and sludge conditions. Therefore, the simulation is performed in combination with the operating conditions such as inflow conditions, aeration, conveyance, surplus, and the like. The removal performance of phosphorus can be raised easily.

As described above, according to the present invention, it becomes possible to support a civil engineering structure, aeration condition, instrumentation, operating conditions, and the like of an appropriate biological reaction tank that satisfies the target treated water condition.

Claims (10)

In the water quality information processing processor for simulating the process of sewage treatment, And a means for inputting sludge concentration information in the reactor and means for calculating microbial concentration information and inert solid concentration information based on the sludge concentration information. The water quality information processing apparatus according to claim 1, further comprising means for calculating microbial concentration information based on a relative difference between sludge concentration information and inert solid concentration information. The water quality information processing apparatus according to claim 1, further comprising means for calculating the autotrophic bacteria concentration using the aerobic solid residence time. The water quality information processing apparatus according to claim 1, further comprising means for calculating phosphorus accumulation bacteria concentration using phosphorus concentration in sludge, phosphorus concentration in inert solids, and phosphorus concentration in microorganisms. The water quality information processing apparatus according to claim 1, further comprising a means for subtracting the autotrophic bacteria concentration and the phosphorus accumulation bacteria concentration from the microbial concentration and calculating the value of the nutrients. The water quality information calculation device according to claim 1, further comprising: a biological model calculation means for calculating a biological reaction, a transport model calculation means for calculating a fluid, and a dissolved oxygen model calculation means for calculating a dissolved oxygen supply capability of the aeration device. Processing unit. The water quality information processing apparatus according to claim 6, wherein said biological model calculating means has means for calculating a time change of sludge concentration information. 8. A sludge settling index of the final settling basin according to claim 6 or 7, further comprising an SVI setting means for setting the sludge settling index of the final settling basin, wherein the transport model calculation means uses the sludge settling index set to the SVI setter. And a means for calculating, and means for calculating the conveyed sludge concentration and the excess sludge concentration. The reaction tank sludge mass, the conveyed sludge mass, and the excess sludge mass according to claim 8, wherein the sludge concentration information calculated by the biological model calculating means and the conveyed sludge concentration and the excess sludge concentration calculated by the transport model calculating means are used. And means for calculating a solids residence time. In the simulation method for simulating the sewage treatment process in the water quality information processing unit, The water quality information processing unit converts the units of autotrophic bacteria concentration, phosphorus accumulation bacteria concentration and tagalife bacteria concentration, and executes the simulation, and the autotrophic bacteria concentration, tagalife bacteria concentration, and phosphorus accumulation bacteria calculated in the simulation are calculated. Convert the unit of the concentration and the concentration of the degradable solids, which is the concentration of the solid substance produced during the self-decomposition of the microorganism, to determine the inert solids concentration, the calculated autotrophic bacteria concentration, the value of the nutrients, the phosphorus accumulation bacteria concentration and the degradable solids concentration. The sludge concentration is calculated by adding to the simulation method.