JP3481678B2 - Operation control method for intermittent aeration type activated sludge water treatment equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method in an intermittent aeration type activated sludge water treatment apparatus for treating sewage / wastewater, and more specifically, to an aeration in an intermittent aeration treatment step. The present invention relates to an operation control method that enables an appropriate water purification treatment by selecting an appropriate operation pattern from a plurality of operation patterns that define the number of times of aeration stop and the respective times, so-called aeration operation patterns.

[0002]

2. Description of the Related Art FIG. 74 shows, for example, JP-A-60-150.
It is a block diagram which shows the conventional intermittent aeration type activated sludge method water treatment apparatus described in Japanese Patent No.894. This equipment consists of a single treatment tank, in which the inflowing wastewater is mixed with the activated sludge and intermittently aerated, and the precipitation which separates the activated sludge from the treated water after the intermittent aeration step is completed. The sewage is treated by sequentially repeating the treatment step and the discharge step of discharging the treated water obtained as the supernatant water from the treatment tank after the completion of the precipitation treatment step. In the figure, 1 is a treatment tank, 2 is an aeration blower, 3 is a dissolved oxygen concentration meter, 4 is an air diffuser, 5 is a computer, and 6 is a valve attached to a pipe f. Further, a is a pipe for introducing sewage into the treatment tank 1, b, c and d are signal lines, e is a pipe for supplying air from the aeration blower 2 to the air diffuser 4, and f is for discharging the treated water after purification. It is piping.

FIG. 75 is an explanatory view showing a so-called aeration operation pattern in which the number of times of repeating aeration and aeration stop in the intermittent aeration process of this apparatus and the respective times are defined.

The operation of this device will be described below. In this device, the inflowing sewage is introduced into the treatment tank 1 through the pipe a and mixed with the activated sludge by the air supplied from the air diffuser 4. In the intermittent aeration treatment process in which aeration and agitation (stopping aeration) are repeated, the aeration blower 2 is intermittently operated to purify the sewage, and in the precipitation treatment process, the aeration blower 2 is stopped to separate the activated sludge and the treated water. To separate. In the discharge step, the valve 6 is opened and the treated water is discharged through the pipe f. When the discharging step is completed, the intermittent aeration processing step and the precipitation processing step are repeated, and the sewage is treated once.

As shown in FIG. 75, in the intermittent aeration process, aeration stop for 45 minutes and aeration for 15 minutes are alternately repeated four times. Also, during the aeration time, as shown in FIG. 74, the dissolved oxygen concentration in the treatment tank 1 is measured by the dissolved oxygen concentration meter 3, and the computer 5 rotates the aeration blower 2 so that this value becomes 2 mg / liter. Control the number.

[0006]

Problems to be Solved by the Invention JP-A-60-1508
As described in Japanese Patent Laid-Open No. 94, the number of repetitions of aeration and aeration stop in the intermittent aeration treatment step and each time are "correspondingly determined by the property of sewage". However, in the conventional method, it is not clear how to specifically determine this, and the experience and can of the maintenance manager of the device had to be relied upon. In the intermittent aeration type activated sludge method water treatment device installed in the fluctuating general sewerage facility, it was difficult to always ensure good water quality.

The present invention has been made to solve the above problems, and in the intermittent aeration process of the intermittent aeration type activated sludge method water treatment device, the number of repetitions of the aeration time and the aeration stop time and each time are set. It is an object of the present invention to obtain an operation control method of an intermittent aeration type activated sludge method water treatment device which can appropriately remove polluted components in wastewater and perform good water purification treatment by setting appropriately.

[0008]

An operation control method of an intermittent aeration type activated sludge method water treatment device according to the present invention is configured as follows.

According to a first aspect of the present invention, there is provided an operation control method for an intermittent aeration type activated sludge method water treatment device, wherein at least two or more operation patterns defining aeration and aeration in the intermittent aeration process are at least aerated. Based on the total time, the number of repetitions of the aeration process, and the length of each aeration process, a pattern with a high aeration effect, for example, a pattern with a high number of repetitions of aeration and aeration stop, a pattern with a low aeration effect, for example, aeration and aeration stop Prioritize the pattern with a small number of repetitions, and treat water quality or plant values, for example, the actual aerobic time when the dissolved oxygen concentration exceeds a predetermined value in the intermittent aeration process, or the dissolved oxygen. The actual anaerobic time when the concentration is below a predetermined value, or the concentration of nitrate nitrogen and concentration of ammonia nitrogen in the treated water Calculate the treatment index of the treated water by a predetermined calculation formula, compare the calculated value with the target value of the predetermined treatment index, and the amount of aeration to be input is insufficient depending on the magnitude of the comparison result. If it is detected that the aeration operation pattern is higher than the currently used aeration operation pattern, on the contrary, if it is detected that the aeration amount to be input is excessive, the aeration operation pattern currently used Change the aeration operation pattern according to a predetermined order to select a pattern with a lower aeration effect
However, the dissolved oxygen concentration in the aeration tank during the intermittent aeration process
Time higher and lower than predetermined dissolved oxygen concentration standard value
The cumulative time ratio of time is used as the processing index .

[0010]

[0011]

[0012]

The operation control method of the intermittent aeration type activated sludge method water treatment device according to claim 2 of the present invention is an intermittent aeration process treatment.
At least two or more defined aeration and cessation of aeration
Operation pattern, at least total aeration time, aeration process
The number of repetitions and the length of each aeration treatment time
High aspiration patterns, such as repeated aeration and deaeration.
A pattern that has a low aeration effect due to a pattern that has many rebounds
A small number of repetitions of aeration and aeration stop
Prioritize the patterns in advance, and
Runt value, for example, the dissolved oxygen concentration in the intermittent aeration process
Substantial aerobic time exceeding a predetermined value, or
Is the actual dissolved oxygen concentration divided by a predetermined value
Anaerobic time, or nitrate nitrogen concentration in treated water and
According to a predetermined calculation formula based on the ammonia nitrogen concentration, etc.
Calculate the treatment index of the treated water and set the calculated value in advance.
This comparison result is compared with the target value of the processing index obtained above.
The amount of aeration to be input depends on the size of the fruit.
If detected, than the aeration operation pattern currently used
Aeration amount selected by selecting a pattern with high aeration effect
Aeration currently used when it is detected that
Select a pattern that has a lower aeration effect than the driving pattern
Change the aeration operation pattern according to a predetermined order
However, the treatment index is the difference between the cumulative time of the dissolved oxygen concentration in the aeration tank in the intermittent aeration treatment step and the cumulative time of the dissolved oxygen concentration higher and lower than the predetermined dissolved oxygen concentration reference value.

[0014]

[0015]

The operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to claim 3 of the present invention, in the operation control method of the intermittent aeration type activated sludge process water treatment apparatus of claim 1, wherein the integration time ratio The target value of the treatment index is set within the range of 1/10 to 10 times the ratio of the denitrification rate of activated sludge to the nitrification rate.

The operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to claim 4 of the present invention, in the operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to claim 2, the difference in integration time The target value of the processing index is set in the range of -1 hour to 1 hour.

The operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to a fifth aspect of the invention, according claim 1
In the operation control method of the intermittent aeration type activated sludge method water treatment device according to any one of the items 4 to 4 , a predetermined dissolved oxygen concentration reference value is set to a range of 0 to ₂ mg-O ₂ / liter. .

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

According to the operation control method of the intermittent aeration type activated sludge method water treatment device according to the first aspect of the present invention, a plurality of aeration operation patterns are prioritized in descending order of aeration effect, and the treated water quality etc. Since the aeration effect is changed according to the order of the aeration effect according to the change in the treatment index, it is possible to secure an appropriate aeration time and aeration stop time even when the amount and properties of the inflowing wastewater fluctuate, and it is stable. Therefore, good treated water quality can be obtained. In addition, in the intermittent aeration process
Dissolved oxygen with a predetermined dissolved oxygen concentration in the aeration tank in
The cumulative time ratio between the time higher than the concentration reference value and the time lower than the concentration reference value is
It is used as a processing index.

[0025]

[0026]

[0027]

According to the operation control method of the intermittent aeration type activated sludge method water treatment device according to the second aspect of the present invention, the dissolved oxygen concentration in the aeration tank in the intermittent aeration treatment step is more than the predetermined dissolved oxygen concentration reference value. The difference between the integrated times of the high time and the low time is used as the processing index.

[0029]

[0030]

According to the operation control method of the intermittent aeration type activated sludge method water treatment device according to the third aspect of the present invention, the target value of the treatment index of the integrated time ratio is the ratio of the denitrification rate and the nitrification rate of the activated sludge. It is set in the range of 1/10 to 10 times.

According to the operation control method of the intermittent aeration type activated sludge method water treatment device according to the fourth aspect of the present invention, the target value of the treatment index of the difference of the integrated time is set in the range of -1 hour to 1 hour. To be done.

According to the operation control method of the intermittent aeration type activated sludge method water treatment device according to claim 5 of the present invention, the predetermined dissolved oxygen concentration reference value is set within the range of 0 to ₂ mg-O ₂ / liter. To be done.

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[Examples] For many years, the inventors of the present invention have used a computer based on a kinetic model as an operation control method for efficiently removing nitrogen and the like in an intermittent aeration type activated sludge method water treatment device to stably perform good water purification treatment. We have repeated the simulation and examined it. As a result, the inventors found some rules useful for appropriately setting the number of times of repeating aeration and aeration stop in the intermittent aeration process in the intermittent aeration type activated sludge method water treatment device and each time, and the present invention. I thought about it.
First, the dynamic model used in the computer simulation will be described below.

The kinetic model of the organic substance removal reaction is expressed by the equation 1. This is the “Real-Time Control of Activated Slu
Stenstr as described in dge Prosess "(ASCE (EE), 1979)
It is based on the om model.

[0041]

[Equation 1]

Here, r *: production rate [mg / liter h] Y *: yield K *: half-saturation constant XT: MLVSS concentration (index of effective concentration of activated sludge)
[Mg / liter] XS: Accumulation partial concentration of MLVSS [mg / liter] XA: Active partial concentration of MLVSS [mg / liter] XI: Inactive partial concentration of MLVSS [mg / liter] fs: XS / XT fs ^M : Maximum value of fs S: Organic matter concentration [mg / liter] _RT : Transfer coefficient [h ^-1 ] R _XA : Maximum specific growth rate [h ^-1 ] R _XI : Maximum specific mortality rate [h ^-1 ].

The kinetic model of the nitrification reaction is expressed by Equation 2. This is also the “Real-Time Control of Activated Slu
Stenstr as described in dge Prosess "(ASCE (EE), 1979)
It is based on the om model.

[0044]

[Equation 2]

Here, XNS: concentration of Nitrosomonas [mg / liter] XNB: concentration of Nitrobacter [mg / liter] DO: dissolved oxygen concentration [mg / liter] μ * (DO): specific growth rate function by Monod [h ^-1 ] μ * M: maximum specific growth rate [h ^-1 ] D *: specific mortality rate [h ^-1 ] r _S *: substrate production rate by nitrification reaction [mg / liter h] r _H *: organic matter removal reaction Substrate production rate [mg
/ Liter h].

Further, the kinetic model of the denitrification reaction is expressed by Equation 3. This is based on “Water Treatment Engineering” (Gihodo Publishing, 1976) and “Biological Denitrification” (Dep. Of Sanitary
Engineering Technical Univ. Of Denmark, 1972).

[0047]

[Equation 3]

[0048] Here, r _D *: velocity generator according denitrifying reaction [mg / l h] R _HN: Biosynthesis type denitrification rate constant [h ^-1] R _SN: endogenous type denitrification rate constant [h ^{- 1} ]

The balance of the dissolved oxygen concentration is expressed by equation 4.

[0050]

[Equation 4]

Here, r _HDO : Oxygen consumption rate [mg / liter h] by removal of organic substances r _NDO : Oxygen consumption rate [mg / liter h] by nitrification r _DO : Oxygen transfer rate [mg / liter h] K _La : Overall oxygen transfer capacity coefficient [h ^-1 ] DOs: Saturated dissolved oxygen concentration [mg / liter].

The kinetic parameters were set as shown in Table 1.

[0053]

[Table 1]

Next, some useful laws discovered by this computer simulation and on which the present invention is based will be described.

The first is "the ratio of the time during which dissolved oxygen remains in the intermittent aeration step, so-called substantial aerobic time, to the time during which dissolved oxygen disappears, so-called substantial anaerobic time. However, when the ratio of the denitrification rate of the activated sludge to the nitrification rate matches, the total nitrogen concentration in the treatment tank becomes minimum ”(hereinafter referred to as the first law). The background of discovering this law will be described below.

The inventors set operating conditions as shown in Table 2 in order to investigate the relationship between the aeration operation pattern and the treated water quality, and performed computer simulations based on the above dynamic model for 30 kinds of aeration operation patterns. went.

[0057]

[Table 2]

FIG. 1 is a diagram showing 30 kinds of aeration operation patterns applied, where the scale on the horizontal axis indicates time, the black areas indicate the aeration time, and the white areas indicate the aeration stop time. Show.

FIG. 2 is a diagram showing the results of the above simulation, in which the horizontal axis represents the time during which the dissolved oxygen remained in the intermittent aeration step, the so-called substantial aerobic time, and the dissolved oxygen disappeared. The ratio of time to the so-called substantial anaerobic time is shown, and the vertical axis shows the sum of the ammonia nitrogen concentration and the nitrate nitrogen concentration at the start of the discharge step, that is, the total nitrogen concentration (mg / liter), and plots it. The number added below a certain point corresponds to the number of the aeration operation pattern. From this figure, it can be seen that there is an optimum value for the ratio of the substantial aerobic time and the substantial anaerobic time, and the aeration operation patterns of Nos. 1, 18, 21, and 25 are substantially equal to each other. Nitrogen removal was good because the ratio of aerobic time to substantial anaerobic time was close to this optimal value.

In order to explain this result, consideration was made in the following discussion.

Paying attention to the balance of the amount of ammonia nitrogen and the amount of nitrate nitrogen in the treatment tank, S ₁ : the amount of ammonia nitrogen at the end of the intermittent aeration process [m
g] S ₂ : Amount of nitrate nitrogen at the end of the intermittent aeration process [mg] L: Amount of ammonia nitrogen flowing into the intermittent aeration process [mg] L ': Amount of ammonia nitrogen carried over from the previous cycle [mg] ] K _N : Nitrification rate [mg / h] k _D : Denitrification rate [mg / h] T: Intermittent aeration treatment process time [h] e: When the aerobic time ratio is satisfied, Equation 5 is established.

[0062]

[Equation 5]

By taking the sum of Equation 5, Equation 6 is established.

[0064]

[Equation 6]

However, since S2 does not take a negative value, an inequality such as Equation 7 holds.

[0066]

[Equation 7]

Applying Equation 7 to Equation 6, e = k _D / (k <sub>N
+ K D), 1-e</sub> = time k _N / a _{(k N + k D),} S 1 + S 2 takes a minimum value _{L '+ L-k N k} D T / (k N + k D). At this time, S ₁ = L ′ + L−k _N k _D T / (k _N + k _D ), S ₂ =
It is 0. That is, when the ratio of aerobic time to anaerobic time matches the ratio of denitrification rate and nitrification rate of activated sludge,
The total nitrogen concentration in the treatment tank is minimal.

The second rule is that "the nitrogen removal rate is good when the ammonia nitrogen concentration and the nitrate nitrogen concentration in the treated water remain to the same extent" (hereinafter referred to as the second law).
Is. The background of discovering this law will be described below.

FIG. 3 is a diagram in which the simulation results of FIG. 2 are summarized again. The horizontal axis shows the difference (mg / liter) between the ammonia nitrogen concentration and the nitrate nitrogen concentration at the start of the discharging process, and the vertical axis. Is the sum of both, that is, the total nitrogen concentration (m
g / liter). According to this figure, the total nitrogen concentration becomes the smallest when all the nitrate nitrogen disappears and a small amount of ammonia nitrogen remains as described above. However, ammoniacal nitrogen is more toxic than nitrate nitrogen, so the above treatment is not always optimal.
However, even if the concentration of ammonia nitrogen and the concentration of nitrate nitrogen remain at the same level, the total nitrogen concentration is quite low, and it can be said that nitrogen removal is performed well. When the concentration and the concentration of nitrate nitrogen remain to the same extent, the nitrogen removal rate is good. "

The third is a law (hereinafter, referred to as a third law) that "the aeration effect is higher as the number of repetitions of aeration and aeration stop is higher." The background of discovering this law will be described below.

In FIG. 4, the operating conditions are set as shown in Table 2,
When the same total aeration time (4 hours per treatment step) is equally divided into 13 times (a) and (d), and when equally divided into 8 times (b)
It is a simulation result which shows the difference in the treated water quality of (e), and when equally divided into 4 times (c) and (f). In FIGS. 4A to 4C, the horizontal axis represents time (hour), the vertical axis represents nitrogen concentration (mg / liter), the solid line represents changes in the ammoniacal nitrogen concentration, and the broken line represents the nitrate nitrogen concentration. Shows changes. In addition, in (d) to (f) of FIG.
The horizontal axis is time (hour), the vertical axis is dissolved oxygen concentration (mg /
Liter). The black and white band under each graph shows the aeration operation pattern. The black areas indicate aeration time, and the white areas indicate aeration stop time. In these figures, in the case of 13 times (a), the ammonia nitrogen concentration is suppressed to the lowest. That is, it can be said that the greater the number of repetitions of aeration and stop of aeration, the longer the remaining time of the dissolved oxygen concentration and the higher the aeration effect. Needless to say, "high aeration effect" means that the remaining time of dissolved oxygen concentration is long and aerobic reaction, for example, nitrification reaction proceeds well, and water quality is not always good. Absent. For example,
If nitrification proceeds too much, the nitrogen content in the sewage will remain in the form of nitrate nitrogen.

The fourth rule is that "the aeration operation pattern has a stronger tendency to gradually decrease with the elapsed time of the intermittent aeration process, the higher the aeration effect" (referred to as the fourth law).
Is. The background of discovering this law will be described below.

In FIG. 5, the conditions are set as shown in Table 2, and the same total aeration time (4 hours per treatment step) is distributed so as to gradually decrease with the elapsed time of the intermittent aeration step and to increase gradually. It is a simulation result which shows the difference in the treated water quality in the case of doing. When the aeration time is gradually reduced, the ammonia nitrogen concentration is slightly lower and the nitrate nitrogen concentration is higher. This tendency was also confirmed in other simulation results. In the intermittent aeration type activated sludge method water treatment device, when the water level rises with the inflow of sewage,
Since the dissolved oxygen concentration increases as the transfer efficiency increases, it can be said that the aeration effect is higher when the aeration time is longer at the beginning of the intermittent aeration process.

Examples of the present invention will be described below with reference to Examples 1 to 47. Here, Examples 1 to 10 show the concentration of nitrate nitrogen and the concentration of ammonia nitrogen in treated water. It shows an example of changing the pattern of aeration operation using the difference as a processing index. In addition, Example 1
1 shows an example in which the aeration operation pattern is changed using the ratio of the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water as the treatment index. In addition, from Example 12 to Example 16, the aeration operation pattern was set using the cumulative time ratio of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher and lower than the predetermined dissolved oxygen concentration reference value as the treatment index. It shows an example of changing the. In addition, Example 17 shows an example in which the difference between the high time integration time and the low time integration time is used as a processing index, and the aeration operation pattern is changed so that this value becomes small. In addition, from Example 18 to Example 32, Example 1 to Example 1
In the configurations up to 1, the aeration effect is ranked in descending order of the total aeration processing time, and various aeration operation patterns are shown. In addition, Example 33
From Example to Example 39, in the configurations of Example 1 to Example 11, various aeration operation patterns are performed in order of increasing aeration effect in the descending order of the number of repetitions of aeration and aeration stop in the intermittent aeration treatment process. This is an example of. In addition, in Example 40 and Example 41,
Example In the configurations of Example 1 to Example 11, the operation pattern in which the aeration processing time in the intermittent aeration processing step is gradually reduced with the elapse of the processing time is set as the order of high aeration effect, and an example of the aeration operation pattern Is shown. In addition, in Example 42, in the configurations of Example 1 to Example 11, the operation pattern in which the aeration stop time in the intermittent aeration process step is gradually increased with the elapse of the processing time is set as the order of high aeration effect. It is an example of an operation pattern.

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 6 is a block diagram showing the intermittent aeration type activated sludge method water treatment device according to the first embodiment, and FIG. 7 is a flowchart showing the processing steps from data collection to control according to the operation control method of the first embodiment. Is. In this Example 1, the treatment index is the difference between the concentration of nitrate nitrogen and the concentration of ammonia nitrogen in the treated water.

In FIG. 6, 7 is a nitrate nitrogen concentration meter for measuring the concentration of nitrate nitrogen in the treated water, 8 is an ammonia nitrogen concentration meter for measuring the concentration of ammonia nitrogen in the treated water, and a pipe It is attached to f. Reference numeral 9 is a calculator for calculating the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water. 7a and 8a are signal lines, which are a nitrate nitrogen concentration meter 7 and an ammonia nitrogen concentration meter 8 respectively.
And the calculator 9 are connected to each other. Reference numeral 10 is a comparison calculator for comparing the calculated value of the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water with a predetermined target value, which is connected to the calculator 9 by a signal line 9a. Reference numeral 11 is a setting device for setting a target value of the difference between the concentration of nitrate nitrogen and the concentration of ammonia nitrogen in the treated water.
It is connected to 0. Reference numeral 17 denotes an input / output circuit, which is connected to the comparison calculator 10 via a signal line 10a. Reference numeral 12 is a display device for displaying the judgment result of the comparison arithmetic unit 10 to the operation manager of the device, and is connected to the input / output circuit 17 through the signal line 12a. Reference numeral 13 is a storage circuit in which a plurality of aeration patterns are ranked and stored in the order of aeration effect, and is connected to the input / output circuit 17 by a signal line 13a. Reference numeral 14 is a setting device for setting an aeration pattern in the memory circuit 13, which is connected to the memory circuit 13 by a signal line 14a. 1
5, the operation manager of the device selects the aeration operation pattern to be actually operated from the plurality of aeration operation patterns,
It is a setting device for setting and is connected to the input / output circuit 17 by the signal line 15a. 16 turns on the aeration blower 2 according to the aeration operation pattern set by the setting device 15.
This is a controller for turning off, and is connected to the input / output circuit 17 by the signal line 17a and the aeration blower 2 by the signal line 16a.

Next, the operation will be described. The difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water is calculated by the calculator 9. The value of the concentration of nitrate nitrogen in the treated water necessary for this calculation is output through the signal line 7a as the output of the nitrate nitrogen concentration meter 7, and the value of the concentration of ammonia nitrogen in the treated water is calculated by the ammonia nitrogen concentration meter 8 Signal line 8 as the output of
It is obtained via a. Further, the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water and the predetermined target value are compared by the comparison calculator 10. The difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water necessary for this comparison calculation is obtained as the output of the calculator 9 via the signal line 9a. The target value to be compared is obtained as the output of the setter 11 via the signal line 11a. In the comparison computing unit 10, if the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water is smaller than the target value, it should shift to a pattern having a higher aeration effect than the aeration operation pattern currently used. to decide. On the other hand, if the calculated value is larger than the target value, it is determined that the aeration operation pattern should be shifted to a pattern having a lower aeration effect than the currently used aeration operation pattern. The determination result is supplied to the display device 12 via the signal line 10a, the input / output circuit 17, and the signal line 12a, and is displayed to the device operation manager. The device operation manager selects one from the plurality of aeration operation patterns stored in the memory circuit 13 with reference to the judgment result of the comparison arithmetic unit 10 displayed on the display device 12, and sets the setting device. Set to 15. The set aeration operation pattern is transmitted to the controller 16 via the signal line 15a, the input / output circuit 17, and the signal line 17a.
The controller 16 controls the aeration blower via the signal line 16a based on the setting result.

Next, details of the data processing of the first embodiment will be described with reference to the flowchart of FIG. Although FIG. 6 shows an example in which the target value is set to one and the aeration operation pattern is changed, it is also effective to provide two target values of the upper limit value and the lower limit value as in FIG. 7.

When the intermittent aeration process is completed, the nitrate nitrogen concentration in the treated water is measured by the nitrate nitrogen concentration meter 7 in step 1s, and the ammonia nitrogen concentration in the treated water is measured by the ammonia nitrogen concentration meter 8 in step 2s. . next,
In step 3s, the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water is calculated by the calculator 9. In step 4s, it is determined whether or not the difference between the nitrate nitrogen concentration in the treated water and the calculated value of the ammonia nitrogen concentration in the treated water is larger than a predetermined target value (upper limit value). In step 5s, it is determined whether the difference between the nitrate nitrogen concentration in the treated water and the calculated value of the ammonia nitrogen concentration in the treated water is smaller than a predetermined target value (lower limit value). Here, when the target value 1 compared in step 4s and the target value 2 compared in step 5s match, the operation is the same as that of the embodiment of FIG.

In step 4s, if the difference between the calculated values of the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water is larger than the target value 1, the comparison calculator 10 determines that the aeration effect is higher than the aeration operation pattern currently used. It is judged that the pattern should be shifted to a lower pattern (step 6s), and the judgment result is displayed on the display device 12. When neither of the conditions of step 4s and step 5s is met, the comparison calculator 10 judges that the aeration operation pattern currently used may be kept, and displays the judgment result on the display device 12 (step 8s). In step 5s, if the difference between the nitrate nitrogen concentration in the treated water and the calculated value of the ammonia nitrogen concentration is smaller than the target value,
The comparison calculator 10 judges that the pattern should be changed to a pattern having a higher aeration effect than the currently used aeration operation pattern (step 7s), and the judgment result is displayed on the display device 12. In step 9s, the operation manager of the apparatus looks at the determination result displayed on the display device 12, selects the aeration operation pattern to be actually operated from the plurality of aeration operation patterns stored in the storage circuit 13, Set in the setting device 15.

FIG. 8 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG. It is the result of the simulation using the parameters shown in FIG. FIG. 10 shows aeration operation patterns stored in the storage circuit 13. These are the patterns in which the aeration processing time and the aeration stopping time per one time do not change during the intermittent aeration process, and the aeration and the aeration stopping time are maintained without changing the predetermined aeration processing time per one time. The number of repetitions was changed and three types were prepared, and the aeration effect was ranked in descending order of the number of repetitions of aeration and aeration stop, that is, in the order of increasing total aeration time in the intermittent aeration process. The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern with a high aeration effect is -2 mg.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern with a low aeration effect was set to 2 mg / liter.

In FIG. 8A, the time (day) is plotted on the horizontal axis and the nitrogen concentration (mg / liter) is plotted on the vertical axis, with the ammonia nitrogen concentration (solid line) and the nitric acid concentration in the treatment tank 1 immediately before the start of the discharging step. It is a graph which shows nitrogen concentration (broken line). Figure 8 (b)
FIG. 4 is a graph showing changes in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. According to this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced. .

Example 2. FIG. 11 is a block diagram showing an intermittent aeration type activated sludge method water treatment device according to a second embodiment of the present invention, and FIG. 12 shows a processing step from data collection to control according to an operation control method of this embodiment. It is a flowchart. In Example 2, the values of the ammonia nitrogen concentration and the nitrate nitrogen concentration in the treated water were measured by manual analysis and set by the operation manager of the apparatus, and an expensive automatic measuring instrument was used. Even if it does not have, the effect similar to Example 1 is acquired.

In FIG. 11, 18 is a setter for setting the concentration of nitrate nitrogen in the treated water, and 19 is a setter for setting the concentration of ammonia nitrogen in the treated water. It is connected.

Next, the operation will be described. In this embodiment, the nitrate nitrogen concentration value and the ammonia nitrogen concentration value in the treated water are set in the setter 18 and the setter 19 by the operation manager of the apparatus, respectively. These values are sent to the calculator 9 via the signal line 18a and the signal line 19a, and the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water is obtained.

Next, details of the data processing of the second embodiment will be described based on the flowchart of FIG.

When the intermittent aeration process is completed, the concentration of nitrate nitrogen in the treated water is changed to Step 18s in Step 17s.
The ammonia nitrogen concentration in the treated water is set in the setting device 17 and the installation device 18, respectively. These steps 17s,
18s are steps 1s and 18s in the process of FIG.
Instead of 2s, steps 3s to 9s are the same as those in the first embodiment shown in FIG.

In addition to the effects of the first embodiment, the second embodiment does not require the nitrate nitrogen concentration meter 7 and the ammonia nitrogen concentration meter 8, and therefore has the effect that the structure of the device is simple and the cost is low.

Example 3. FIG. 13 is a block diagram showing an intermittent aeration type activated sludge method water treatment device according to a third embodiment of the present invention, and FIG. 14 shows a processing step from data collection to control according to an operation control method of this embodiment. It is a flowchart. In this Example 3, the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water are calculated from the dissolved oxygen concentration in the treatment tank, the inflow rate of the sewage and the amount of the sewage accumulated in the treatment tank. The same effect as in Example 1 can be obtained without using an expensive nitrate nitrogen concentration meter and ammonia nitrogen concentration meter.

In FIG. 13, 20 is a dissolved oxygen concentration meter for measuring the dissolved oxygen concentration in the treatment tank, 21 is a flow meter attached to the pipe a for measuring the inflow rate of sewage, and 22 is the treatment tank. It is a water level gauge that measures the water level inside.

Reference numeral 23 is a calculator for calculating the amount of ammonia nitrogen decomposed, that is, the amount of nitrate nitrogen produced, which is connected to the dissolved oxygen concentration meter 20 via a signal line 20a. Reference numeral 24 is a setting device for setting a coefficient for calculating the amount of ammonia nitrogen decomposition, that is, the amount of nitrate nitrogen production.
It is connected to the calculator 24 at a.

Reference numeral 25 denotes a calculator for calculating the amount of nitrate nitrogen decomposition, which is connected to the dissolved oxygen concentration meter 20 via a signal line 20b. Reference numeral 26 is a setter for setting a coefficient for calculating the amount of nitrate nitrogen decomposition, and is connected to the calculator 25 by a signal line 26a.

Reference numeral 27 is a computing unit for computing the amount of inflowing ammoniacal nitrogen, which is connected to the flowmeter 21 via a signal line 21a. Reference numeral 28 is a setting device for setting the concentration of inflowing ammoniacal nitrogen.
Connected with.

Reference numeral 29 is a calculator for calculating the amount of sewage accumulated in the treatment tank, which is connected to the water level gauge 22 via the signal line 22a.
Connected with.

Reference numeral 30 is an arithmetic unit for calculating the concentration of ammonia nitrogen in the treated water. The arithmetic unit 2 is connected to the signal line 27a.
7 and the signal line 23a, and the signal line 29a and the calculator 29, respectively.

Reference numeral 31 is an arithmetic unit for calculating the concentration of nitrate nitrogen in the treated water. The arithmetic unit 23 is connected to the signal line 23b.
The signal line 25a is connected to the calculator 25, and the signal line 29b is connected to the calculator 29.

Further, 30a and 31a are signal lines,
The arithmetic unit 30, the arithmetic unit 31, and the arithmetic unit 9 are connected to each other.

Next, the operation will be described. The ammonia nitrogen amount NH4in flowing in per unit time is calculated by, for example, Equation 8.1, and the inflow flow rate Q of sewage per unit time
It is obtained by multiplying in by the inflowing ammoniacal nitrogen concentration Cin. The ammonia nitrogen amount ΣNH4in flowing in during one cycle of the intermittent aeration process is the ammonia nitrogen amount NH4in flowing in per unit time.
Is calculated over one cycle of the intermittent aeration process. The calculation and integration are performed by the calculator 27. The inflow flow rate Qin is the flowmeter 21.
The inflowing ammoniacal nitrogen concentration Cin is obtained as the output of the setting device 28 through the signal line 21a, and the inflowing ammonia nitrogen concentration Cin is obtained as the output of the setting device 28 through the signal line 28a.

Ammonia nitrogen decomposition amount per unit time, that is, nitrate nitrogen generation amount per unit time NH4
rem is obtained by applying the dissolved oxygen concentration DOr in the processing tank 1 to, for example, equation 8.2. Further, the amount of ammonia nitrogen decomposed during one cycle of the intermittent aeration process, that is, the amount of nitrate nitrogen produced ΣNH4rem during one cycle of the intermittent aeration process, is the amount of decomposed ammonia nitrogen per unit time, that is, the amount of nitrate per unit time. It is determined by integrating the nitrogen production amount NH4rem over one cycle of the intermittent aeration process. The calculation and integration are performed by the calculator 23. The dissolved oxygen concentration DOr in the processing tank 1 is obtained as an output of the dissolved oxygen concentration meter 20 via the signal line 20a.

NO3 decomposing amount of nitrate nitrogen per unit time NO3
rem is obtained by applying the dissolved oxygen concentration DOr in the processing tank 1 to, for example, the equation 8.3. Degradation of nitrate nitrogen in one cycle of intermittent aeration process ΣNO3rem
Is calculated by integrating the nitrate nitrogen decomposition amount NO3rem per unit time over one cycle of the intermittent aeration treatment process. The calculation and integration are performed by the calculator 25. The dissolved oxygen concentration DO in the processing tank 1
r is obtained as an output of the dissolved oxygen concentration meter 20 via the signal line 20b.

Sewage amount Vr accumulated in the treatment tank 1
Is calculated by multiplying the water level Hr of the treatment tank 1 by the bottom area Ar of the treatment tank 1 in the arithmetic unit 29, for example, according to equation 8.4. The water level Hr of the treatment tank 1 is obtained as an output of the water level gauge 22 via the signal line 22a.

Ammoniacal nitrogen concentration in treated water NH4o
ut is obtained by calculating the balance of ammonia nitrogen by the calculator 30 by, for example, the formula 8.5. In the formula 8.5, NH4b is the amount of ammonia nitrogen carried over from the previous intermittent aeration process, the ammonia nitrogen concentration NH4out in the treated water at the end of the previous intermittent aeration process and the inside of the treatment tank 1 at the end of the discharge process. It can be simply obtained by multiplying it by the sewage amount Vr accumulated in. ΣNH4in is a value obtained by integrating the ammonia nitrogen amount NH4in flowing in per unit time over one cycle of the intermittent aeration treatment process, and is obtained as an output of the calculator 27 via the signal line 27a. ΣNH4rem
Is a value obtained by integrating the amount of ammonia nitrogen decomposed per unit time, that is, the amount of nitrate nitrogen produced per unit time NH4rem over one cycle of the intermittent aeration process, and is output via the signal line 23a as the output of the calculator 23. Obtained. The sewage amount Vr accumulated in the treatment tank 1 is obtained as an output of the calculator 29 via the signal line 29a.

Nitrate nitrogen concentration in treated water NO3out
Is calculated by calculating the balance of nitrate nitrogen by the calculator 31, for example, by the formula 8.6. NO3
b is the amount of nitrate nitrogen carried over from the previous intermittent aeration process, the concentration of nitrate nitrogen NO3out in the treated water at the end of the previous intermittent aeration process and the treatment tank 1 at the end of the discharge process.
It can be simply obtained by multiplying it by the sewage amount Vr accumulated inside. ΣNH4rem is a value obtained by integrating the amount of ammonia nitrogen decomposed per unit time, that is, the amount of nitrate nitrogen produced per unit time NH4rem over one cycle of the intermittent aeration process, and the signal line 23b is output as the output of the calculator 23. Obtained through. ΣNO3rem
Is a value obtained by integrating the amount of nitrate nitrogen decomposition NO3rem per unit time over one cycle of the intermittent aeration process, and is obtained as the output of the calculator 25 via the signal line 25a. The sewage amount Vr accumulated in the treatment tank 1 is
The output of the arithmetic unit 29 is obtained via the signal line 29b.

The difference between the concentration of nitrate nitrogen and the concentration of ammonia nitrogen in the treated water is calculated by the calculator 9. The value of the nitrate nitrogen concentration in the treated water is obtained as the output of the calculator 31 via the signal line 31a, and the value of the ammonia nitrogen concentration in the treated water is obtained as the output of the calculator 30 via the signal line 30a. .

[0105]

[Equation 8]

In the above formula 8, NH4in is the amount of ammonia nitrogen flowing in per unit time, Qin is the inflow rate of sewage per unit time, Cin is the concentration of inflowing ammoniacal nitrogen, and NH4rem is the ammoniacal amount per unit time. Nitrogen decomposition amount, that is, nitrate nitrogen generation amount per unit time, DOr is the dissolved oxygen concentration in the treatment tank 1, NO3
rem is the amount of nitrate nitrogen decomposition per unit time, Vr is the amount of sewage accumulated in the treatment tank 1, Hr is the water level of the treatment tank 1, Ar is the bottom area of the treatment tank 1, and NH4out is ammoniacal in the treated water. Nitrogen concentration, NH4b is the amount of ammonia nitrogen carried over from the previous intermittent aeration process, ΣNH4
in is the amount of ammonia nitrogen flowing in per unit time N
A value obtained by integrating H4in over one cycle of the intermittent aeration treatment process, ΣNH4rem is an ammonia nitrogen decomposition amount per unit time, that is, a nitrate nitrogen production amount per unit time NH4rem is integrated over one cycle of the intermittent aeration treatment process. Value, NO3out is the concentration of nitrate nitrogen in the treated water, NO3b is the amount of nitrate nitrogen carried over from the previous intermittent aeration process, ΣNO3rem is the amount of nitrate nitrogen decomposed per unit time NO3rem during one cycle of the intermittent aeration process Value accumulated over k1, k
2, k3 and k4 are constants. Regarding these constants, literature values may be used, or values obtained by parameter estimation experiments may be used.

Further, the equations 8.1 to 8.6 are not limited to these, and for example, the equation 8.2 is like the equation 9.1, and the equation 8.3 is like the equation 9.2. It can also be calculated with a simple formula.

[0108]

[Equation 9]

Here, k5 and k6 are constants. Regarding these constants, literature values may be used, or values obtained by parameter estimation experiments may be used.

Next, details of the data processing of the third embodiment will be described based on the flowchart shown in FIG.

When the intermittent aeration process starts, step 2
The dissolved oxygen concentration meter 19 measures the dissolved oxygen concentration DOr in the treatment tank 1 at 0 s, the flow meter 20 measures the sewage inflow rate Qin per unit time at step 21 s, and the step 22 s.
Then, the water level Hr of the treatment tank 1 is continuously measured by the water level meter 21.

In step 23s, for example, by multiplying the water level Hr of the treatment tank 1 by the bottom area Ar of the treatment tank 1 according to the equation 8.4, the sewage amount Vr accumulated in the treatment tank 1 is calculated.
Ask for. In step 24s, for example, by multiplying the inflow flow rate Qin of sewage per unit time by the inflowing ammoniacal nitrogen concentration Cin by the formula 8.1, the ammoniacal nitrogen amount NH4in flowing in per unit time is obtained, and this is used in the intermittent aeration process step. Accumulate over one cycle (calculation of ΣNH4in). In addition, during aeration, in step 25 s, for example, the amount of ammonia nitrogen decomposed per unit time, that is, the amount of nitrate nitrogen produced per unit time NH4rem is obtained by, for example, Equation 8.2, and this is calculated during one cycle of the intermittent aeration process. (ΣNH
4 rem calculation). During aeration stop, in step 26s,
For example, the nitrate nitrogen decomposition amount NO3rem per unit time is calculated by the equation 8.3, and this is integrated over one cycle of the intermittent aeration process (calculation of ΣNO3rem).

When the intermittent aeration process is completed, step 27
s, for example, by the equation 8.6, the sewage amount Vr accumulated in the treatment tank 1 obtained in step 23s, step 25s
ΣNH4rem obtained in step ΣN obtained in step 26s
N3 concentration in treated water using O3rem NO3o
ask for ut. Further, in step 28s, for example, by the formula 8.5, the sewage amount Vr accumulated in the treatment tank 1 obtained in step 23s, and ΣNH4i obtained in step 24s.
n, the ammoniacal nitrogen concentration NH4out in the treated water is obtained using ΣNH4rem obtained in step 25s.
Then, in step 3s, the nitrate nitrogen concentration N in the treated water is increased.
O3out and ammonia nitrogen concentration in treated water NH4o
Find the difference from ut. Hereinafter, steps 3s to 9s are the same as those in FIG. 7 shown in the first embodiment.

In the third embodiment, in addition to the effects of the first embodiment, the nitrate nitrogen concentration meter 7 and the ammonia nitrogen meter 8 are not required, so that the structure of the apparatus can be inexpensive.

Example 4. FIG. 15 is a block diagram showing an intermittent aeration type activated sludge method water treatment device according to a fourth embodiment of the present invention, and FIG. 16 shows a processing step from data collection to control according to the operation control method of this embodiment. It is a flowchart. In this Example 4, the concentration of nitrate nitrogen in the treated water is calculated by calculating the concentration of ammonia nitrogen in the treated water from the concentration of dissolved oxygen in the treatment tank and the inflow rate of sewage. The same effect as that of the first embodiment can be obtained by using a measuring instrument (the water level meter 22 is not used) which is smaller than that of the third embodiment without using the nitrogen concentration meter.

In FIG. 15, reference numeral 32 is a calculator for calculating the amount of sewage accumulated in the treatment tank.
It is connected to the flow meter 21 at 1b. The computing unit 32 is a computing unit 30 for computing the ammoniacal nitrogen concentration in the treated water via the signal line 32a, and the computing unit 31 for computing the nitrate nitrogen concentration in the treated water via the signal line 32b.
And are connected respectively.

Next, the operation will be described. In the fourth embodiment, the sewage amount Vr accumulated in the treatment tank is obtained by the arithmetic unit 32, for example, by integrating the inflow flow rate Qin of sewage per unit time from the start of the intermittent aeration treatment process according to Equation 10. To be V0 is the amount of sewage accumulated in the treatment tank 1 at the start of the intermittent aeration treatment process. Normal,
Since the treated water is discharged to a fixed fixed water level, V0
May be set in the calculator 32 with the residual water amount at this time as a constant value. Sewage inflow rate Qi per unit time
n is obtained as an output of the flow meter 21 via the signal line 21b.

The sewage amount Vr accumulated in the treatment tank, which is the calculation result, is calculated by the calculator 30 for calculating the ammonia nitrogen concentration in the treated water via the signal line 32a.
Further, it is sent to the calculator 31 for calculating the nitrate nitrogen concentration in the treated water via the signal line 32b.

[0119]

[Equation 10]

Note that Vr is the amount of sewage accumulated in the treatment tank 1, and ΣQin is the inflow rate Q of sewage per unit time.
In, the cumulative amount from the start of the intermittent aeration treatment process, V0 is the amount of sewage accumulated in the treatment tank 1 at the start of the intermittent aeration treatment process.

Next, details of the data processing of the fourth embodiment will be described based on the flowchart shown in FIG. In this flowchart, step 22s shown in FIG. 14 is omitted, and step 23s of FIG.
All are the same as in FIG. 14 except that they are changed to 3's.

When the intermittent aeration process starts, step 2
The dissolved oxygen concentration meter 20 measures the dissolved oxygen concentration DOr in the treatment tank 1 at 0 s, and the flow meter 21 measures the inflow flow rate Qin of sewage per unit time at step 21 s. In step 23s, for example, the inflow flow rate Qin of sewage per unit time is integrated from the start of the intermittent aeration treatment process by the formula 10 (calculation of the sewage amount Vr accumulated in the treatment tank 1).

In addition to the effects of the third embodiment, the fourth embodiment does not require the water level gauge 22, which has the effect of simplifying the structure of the apparatus.

Example 5. FIG. 17 is a block diagram showing an intermittent aeration type activated sludge method water treatment device according to a fifth embodiment of the present invention, and FIG. 18 relates to an operation control method of the fifth embodiment and shows processing steps from data collection to control. It is a flowchart shown. In this Example 5, the concentration of nitrate nitrogen in the treated water is calculated from the concentration of dissolved oxygen in the treatment tank and the water level in the treatment tank, and an expensive nitrate nitrogen concentration meter and ammonia are used. An effect similar to that of the first embodiment can be obtained by using a measuring instrument (no flow meter 21 is used) which is smaller than that of the third embodiment without using the nitrogen concentration meter.

In FIG. 17, reference numeral 33 is a calculator for calculating the inflow rate of sewage per unit time, which is connected to the water level gauge 22 via a signal line 22b. The calculator 33 is connected to the calculator 27 for calculating the concentration of ammonia nitrogen flowing in via the signal line 33a.

Next, the operation will be described. In this embodiment, the inflow flow rate Qin of the sewage per unit time is calculated by the calculator 33, for example, from the equation 11 as the amount of increase in the water level per unit time {Hr (t + Δt) −Hr (t)} in the treatment tank. It is obtained by multiplying the base area Ar by 1. The water level Hr (t) of the treatment tank 1 is obtained as the output of the water level gauge 22 by solving the signal line 22b.

The inflow flow rate Qin of sewage per unit time, which is the calculation result, is sent to the calculator 27 for calculating the concentration of inflowing ammoniacal nitrogen through the signal line 33a.

[0128]

[Equation 11]

Note that Qin is the inflow rate of sewage per unit time, Hr (t) is the water level of the processing tank 1 at an arbitrary time t, Δt is the unit time, and Ar is the bottom area of the processing tank 1.

Next, the details of the data processing of the fifth embodiment will be described based on the flowchart shown in FIG. In this flowchart, step 21s shown in FIG. 14 is omitted, and step 29s for calculating the inflow flow rate by calculation is provided instead.

When the intermittent aeration process starts, step 2
The dissolved oxygen concentration meter 20 measures the dissolved oxygen concentration DOr in the treatment tank 1 at 0 s, and the water level meter 22 measures the water level in the treatment tank 1 at step 22 s. In step 29s, the amount of rise of the water level per unit time {Hr (t
By multiplying + Δt) −Hr (t)} by the bottom area Ar of the processing tank 1, the inflow flow rate Qin of sewage per unit time
Is calculated.

In this embodiment, in addition to the effects of the third embodiment,
Since the flow meter 21 is not required, there is an effect that the structure of the device is simplified.

Example 6. FIG. 19 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to a sixth embodiment of the present invention, and FIG. 20 shows a processing step from data collection to control according to an operation control method of this embodiment. It is a flowchart. This example calculates the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water without using any of the nitrate nitrogen concentration meter, the ammonia nitrogen concentration meter, the dissolved oxygen concentration meter, the flow meter and the water level meter. The measuring instruments (dissolved oxygen concentration meter 2)
0, the flow meter 21 and the water level meter 22 are not used), the effect similar to that of the first embodiment can be obtained.

In FIG. 19, reference numeral 35 is a setting device for setting the inflow flow rate of sewage per unit time. The setting device 35 is for calculating the ammonia nitrogen concentration flowing in through the signal line 35a, and the signal line 35a. In 35b, it is connected to a calculator 32 for calculating the amount of sewage accumulated in the treatment tank.

Reference numeral 36 is an integrator for integrating the amount of ammonia nitrogen decomposed, that is, the amount of nitrate nitrogen produced. The signal line 36a is an arithmetic unit 30 for calculating the ammonia nitrogen concentration in the treated water and the signal line 36b. With a calculator 31 for calculating the concentration of nitrate nitrogen in the treated water with the signal line 24
It is connected to a setter 24 for setting a constant for accumulating the amount of ammonia nitrogen decomposed, that is, the amount of nitrate nitrogen produced.

Reference numeral 37 is an integrator for integrating the amount of nitrate nitrogen decomposition, which is an arithmetic unit 31 for calculating the concentration of nitrate nitrogen in the treated water on the signal line 37a, and a nitrate nitrogen decomposer on the signal line 25a. Each is connected to a setter 25 for setting a constant for accumulating the quantity. In addition, the integrator 36 and the integrator 37 are connected to the aeration blower 2 by the signal lines 2a and 2b.
Connected with.

Next, the operation will be described. In Example 6, the ammonia nitrogen decomposition amount in one cycle of the intermittent aeration treatment process, that is, the nitrate nitrogen decomposition amount ΣNH4rem in one cycle of the intermittent aeration treatment process was calculated by the integrator 36 as the ammonia nitrogen decomposition per unit time. The amount, that is, the amount of nitrate nitrogen produced per unit time NH4rem is calculated by integrating over one cycle of the intermittent aeration treatment process. However, this integration is performed only during the aeration time, and signals for initialization, interruption, etc. of the integration are provided on the signal line 2.
It is obtained from the blower 2 via a. Further, the ammonia nitrogen decomposition amount per unit time, that is, the nitrate nitrogen decomposition amount NH4rem per unit time is obtained as an output of the setter 24 via the signal line 24a.

The nitrate nitrogen decomposition amount ΣNO3rem during one cycle of the intermittent aeration treatment process is obtained by integrating the nitrate nitrogen decomposition amount NO3rem per unit time in one cycle of the intermittent aeration treatment process in one cycle. . However, this integration is performed only during the aeration stop time, and signals for initialization, interruption, etc. of the integration are provided on the signal line 2b.
It is obtained from the blower 2 via. The nitrate nitrogen decomposition amount NO3rem per unit time is obtained as an output of the setting device 26 via the signal line 26a.

The inflow flow rate Qin of sewage per unit time is set in the setter 35. This value is sent to the calculator 27 for calculating the concentration of ammonia nitrogen inflowing through the signal line 35a. Further, the sewage amount Vr accumulated in the treatment tank is obtained by the computing unit 32, for example, by integrating the inflow flow rate Qin of the sewage per unit time from the start of the intermittent aeration treatment process by the formula 10. The inflow flow rate Qin of sewage per unit time is obtained as an output of the setting device 35 via the signal line 35b.

Details of the data processing will be described below with reference to the flowchart shown in FIG. In this flowchart, steps 20s to 26s shown in FIG. 14 are replaced with steps 33s to 36s, and the other steps are the same as those in FIG.

When the intermittent aeration process starts, step 12s
Then, for example, the inflow flow rate Qin of the sewage per unit time is integrated from the start of the intermittent aeration processing step (integration of Vr) according to Expression 10. In step 13s, for example, by multiplying the inflowing flow rate Qin of sewage per unit time by the inflowing ammoniacal nitrogen concentration Cin according to Equation 8.1, the ammoniacal nitrogen amount NH4in flowing in per unit time is obtained, and this is used in the intermittent aeration process step. Accumulate over 1 cycle (accumulation of ΣNH4in). Also, during aeration, in step 14s, the amount of ammonia nitrogen decomposition per unit time,
That is, the amount of decomposed nitrate nitrogen per unit time NH4re
Integrate m (integration of ΣNH4rem). While the aeration is stopped, the nitrate nitrogen decomposition amount NO3rem per unit time is integrated in step 15s (ΣNO3rem integration).

In addition to the effects of the third embodiment, the sixth embodiment does not require any of the dissolved oxygen concentration meter 20, the flow meter 21, and the water level meter 22, and thus has the effect of simplifying the structure of the apparatus. .

Example 7. In Example 6, the dissolved oxygen concentration meter, the flow meter, and the water level gauge were not used, and the ammonia nitrogen concentration and the nitrate nitrogen concentration were obtained by the estimation calculation. However, as Example 7, any one measuring instrument was used. It is needless to say that the calculation can be performed by using it, and even in this case, in addition to the effect of the third embodiment, there is an effect that the configuration of the device becomes simpler.

Example 8. In Examples 6 and 7, the case where the inflowing ammoniacal nitrogen concentration or the inflowing sewage amount is set, and the case where both of them are set are shown, but as Example 8, one average value is set. Instead of this, a plurality of times and corresponding values may be set, that is, a pattern of the inflow ammoniacal nitrogen concentration or the inflow sewage amount may be set. Play. The device configuration of the embodiment in this case is the same as that of FIG. 19, and the setting device 35 may be set with a plurality of times and corresponding values as a pattern.

Example 9. In Examples 1 to 8, an example in which the aeration operation pattern is changed using a value obtained by subtracting the ammonia nitrogen concentration from the nitrate nitrogen concentration in the treated water as a treatment index has been shown. The aeration operation pattern may be changed using a value obtained by subtracting the concentration of volatile nitrogen as a processing index, and in this case as well, Examples 1 to 8 are used.
Has the same effect as.

Example 10. In place of the nitrate nitrogen concentration used in the above example, the nitrification nitrogen concentration, that is, the sum of the nitrite nitrogen concentration and the nitrate nitrogen concentration may be used in Example 10, and in this case also, the same as in the above example. Produce an effect.

Example 11. In Examples 1 to 10, an example was shown in which the aeration operation pattern was changed using the difference between the nitrate nitrogen concentration and the ammonia nitrogen concentration in the treated water as the treatment index. However, the second law “treatment” discovered by the inventors was used. The nitrogen removal rate is good when the amounts of ammonia nitrogen and nitrate nitrogen in the water remain to the same extent. "Says that the treatment index is the ratio of the nitrate nitrogen concentration to the ammonia nitrogen concentration in the treated water. However, it is clear that the same effects as those of Examples 1 to 10 are obtained. In this case, as Example 11, Examples 1 to
A device similar to that shown in FIG.
1, FIG. 13, FIG. 15, FIG. 17, and FIG. 19 may be almost the same. In these figures, the calculator 9 calculates the ratio of the ammonia nitrogen concentration and the nitrate nitrogen concentration in the treated water,
The comparison calculator 10 may be used for comparison with a management target value (for example, a value in the range of 0.1 to 10) of the ratio set by the setter 11. Further, the details of the data processing are almost the same as those in FIGS. 7, 12, 14, 16, 18, and 20, and the ratio of the ammoniacal nitrogen to the nitrate nitrogen in the treated water is calculated in step 3s. And perform step 4
The upper limit value and the lower limit value may be compared at s and 5 s, respectively. At this time, it goes without saying that either the value obtained by dividing the nitrate nitrogen concentration in the treated water by the ammonia nitrogen or the value obtained by dividing the nitrate nitrogen concentration by the ammonia nitrogen concentration may be used.

Example 12. 21 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to the twelfth embodiment, and FIG. 22 is a flow chart showing processing steps from data collection to control according to the operation control method of this embodiment. . In Example 12, the processing time is the cumulative time ratio of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher than the predetermined dissolved oxygen concentration reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value.

In FIG. 21, 38 is a counter for counting the time when the dissolved oxygen concentration is higher than a predetermined reference value, and is connected to the dissolved oxygen concentration meter 20 via a signal line 20a. Reference numeral 39 is a setting device for setting a reference value of the dissolved oxygen concentration, which is connected to the counter 38 by a signal line 39a. A counter 40 counts the time when the dissolved oxygen concentration is lower than a predetermined reference value, and is connected to the dissolved oxygen concentration meter 20 via a signal line 20b. Reference numeral 41 is a setting device for setting the reference value of the dissolved oxygen concentration, and the signal line 41
It is connected to the counter 40 at a. Reference numeral 42 denotes an arithmetic unit for calculating an integrated time ratio between a time when the dissolved oxygen concentration is higher than a predetermined reference value and a time when the dissolved oxygen concentration is lower than the predetermined reference value. The counter 38 is provided by the signal line 38a and the signal line 40a.
And the counter 40, respectively. Reference numeral 43 denotes a comparison calculator that compares a calculated value of an integrated time ratio between a time when the dissolved oxygen concentration is higher than a predetermined reference value and a time when the dissolved oxygen concentration is lower than the predetermined reference value with a predetermined target value. 42a is connected to the calculator 42. Reference numeral 44 denotes a setter that sets a target value of an integrated time ratio between a time when the dissolved oxygen concentration is higher than a predetermined reference value and a time when the dissolved oxygen concentration is lower than the predetermined reference value, and is connected to the comparison calculator 43 by a signal line 44a. ing. The comparison calculator 43 is connected to the input / output circuit 17 via a signal line 43a.

Next, the operation will be described. The arithmetic unit 42 calculates the integrated time ratio ratio of the time when the dissolved oxygen concentration is higher than the predetermined reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value. When the dissolved oxygen concentration required for this calculation is higher than a predetermined reference value, the signal line 38a is output as the output of the counter 38.
The time when the dissolved oxygen concentration is lower than a predetermined reference value is obtained as the output of the counter 40 through the signal line 40a. To compare the calculated value of the cumulative time ratio with the target value,
If the calculated value is larger than the target value, it is judged that it is necessary to shift to a pattern having a lower aeration effect than the currently used aeration operation pattern, and the calculated value is the target. If it is smaller than the value, it is judged that the pattern should be shifted to a pattern having a higher aeration effect than the currently used aeration operation pattern.

Next, the details of the data processing of the twelfth embodiment will be described.
This will be described based on the flowchart of data processing from data collection to control shown in FIG.

When the intermittent aeration process starts, step 30s
Then, the dissolved oxygen concentration meter 20 measures the dissolved oxygen concentration in the processing tank 1. In step 31s, the time during which the dissolved oxygen concentration in the processing tank 1 is higher than a predetermined reference value is set in step 32s.
Then, the time when the dissolved oxygen concentration in the treatment tank 1 is lower than a predetermined reference value is counted.

When the intermittent aeration process is completed, step 33
At s, the calculator 42 calculates the integrated time ratio between the time when the dissolved oxygen concentration in the processing tank 1 is higher than the predetermined reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value. In step 34s,
It is determined whether or not the calculated value of the integrated time ratio is larger than the target value. In step 35s, it is determined whether or not the calculated value of the integrated time ratio is smaller than the target value.

In step 34s, if the calculated value of the integrated time ratio is larger than the target value, the comparison calculator 43 judges that the aeration operation pattern should be lower than the currently used aeration operation pattern. Display the judgment result 12
To display. If the calculated value of the integrated time ratio is smaller than the target value in step 35s, the comparison calculator 43 judges that the aeration effect pattern should be shifted to a pattern having a higher aeration effect than the currently used aeration operation pattern, and the judgment result is determined. Display device 12
To display. Steps 6s to 9s are the same as in FIG.

21 and 22, an example in which the reference values for counting the substantial aerobic time and the anaerobic time can be separately set is shown, but the same values may be set. Also,
Although FIG. 21 shows the case where there is one target value for determining the change of the aeration operation pattern, as shown in FIG.
Two lower limit target values may be provided. That is, the target value of the cumulative time ratio when shifting to the pattern having a high aeration effect may be different from the target value of the cumulative time ratio when shifting to the pattern having a low aeration effect.

FIG. 23 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. The aeration operation pattern used what was shown in FIG. The standard value of dissolved oxygen concentration is 0.5 mg /
It was liter.

As described in "Study on denitrification characteristics of oxidation ditch by intermittent aeration system" (20th Annual Conference on Water Pollution Society, 1986), nitrification rate of activated sludge is generally 0. 0013 (1 / h),
It is said that the denitrification rate is about 0.002 (1 / h). That is, the ratio between the denitrification rate and the nitrification rate was 1.54.
Therefore, referring to this value, the target value of the cumulative time ratio when shifting to a pattern having a high aeration effect is 1, and the target value of the cumulative time ratio when shifting to a pattern having a low aeration effect is 1.7. Was set.

FIG. 23A shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 23
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. According to this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced. .

Example 13 In Example 12, the aeration operation pattern was changed using a value obtained by dividing the integrated time of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher than the predetermined dissolved oxygen concentration reference value by the integrated time of the low time as a processing index. However, as the thirteenth embodiment, the aeration operation pattern may be changed using the value obtained by dividing the low time integration time by the high time integration time as the processing index. The same effect as in Example 12 is obtained.

Example 14 Examples 12 and 13 show examples in which the aeration operation pattern is changed using the cumulative time ratio of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher than the predetermined dissolved oxygen concentration reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value. However, in view of the circumstances leading to the discovery of the above-mentioned first law, a value obtained by dividing the integrated time of the time when the dissolved oxygen concentration is higher than the reference value by the time of the intermittent aeration treatment process or the value thereof as Example 14. The aeration operation pattern may be changed using the reciprocal number as the processing index, and even in this case, the same effect as that of the twelfth and thirteenth embodiments can be obtained. In this case, as the device, the signal lines 20b, 41a, 4 of FIG.
0a, the counter 40 becomes unnecessary, and the arithmetic unit 42 may divide the integrated time of the time when the dissolved oxygen concentration obtained from the signal line 38a is higher than the reference value and the time of the entire intermittent aeration process.

Example 15. Examples 12 and 13 show examples in which the aeration operation pattern is changed using the cumulative time ratio of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher than the predetermined dissolved oxygen concentration reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value. However, in view of the circumstances leading to the discovery of the above-mentioned first law, as Example 15, a value obtained by dividing the integrated time of the time when the dissolved oxygen concentration is lower than the reference value by the time of the entire intermittent aeration process or Even if the aeration operation pattern is changed using the reciprocal number as the processing index, the same effect as in the twelfth and thirteenth embodiments is obtained. In this case, the device shown in FIG.
The signal lines 20a, 39a, 38a and the counter 38 are unnecessary, and the arithmetic unit 42 divides the integrated time of the dissolved oxygen concentration obtained from the signal line 40a lower than the reference value and the time of the entire intermittent aeration process. I'm fine.

Example 16. In Examples 12 to 15, attention was paid to the dissolved oxygen concentration in the intermittent aeration treatment step, but in Example 16, this was included in consideration of the possibility that the denitrification reaction could occur in part or all of the precipitation treatment step. The dissolved oxygen concentration may be measured within the time.

Example 17 Examples 12 to 16 show examples in which the aeration operation pattern is changed using the cumulative time ratio of the time when the dissolved oxygen concentration in the aeration tank in the intermittent aeration treatment step is higher than the predetermined dissolved oxygen concentration reference value and the time when the dissolved oxygen concentration is lower than the predetermined reference value. However, as shown in the twelfth embodiment, it is better to set the target value of this processing index in the vicinity of 1. Therefore, as a seventeenth embodiment, the difference between the high time integration time and the low time integration time is calculated as the processing index. As an alternative, the aeration operation pattern may be changed so that this value becomes very small, and even in this case, the same effects as those of the twelfth and thirteenth embodiments are obtained. In this case, as a concrete example, the same as those of the twelfth to sixteenth embodiments are conceivable, and the device configuration may be almost the same as that of FIG.
In 2, the difference between the substantial aerobic time and the anaerobic time is calculated, and in the comparison calculator 43, the difference is compared with the management target value of the difference set by the setter 44 (for example, the value in the range of -1 hour to 1 hour). Will be done. The details of the data processing are also the same as in FIG. 22, and the difference between the substantial aerobic time and the anaerobic time may be calculated in step 33s. At this time, it goes without saying that either a value obtained by subtracting the integration time of the low time from the integration time of the high time or a value obtained by subtracting the integration time of the high time from the integration time of the low time may be used.

Example 18. FIG. 24 shows Embodiment 1 of the present invention
Aerated operation patterns 1B to 3B according to No. 8
Which are stored in the storage circuit 13. In this Example 18, the aeration operation pattern in which the aeration processing time and the aeration stopping time per one time are unchanged through the intermittent aeration processing step was performed without changing the predetermined number of times of repeating aeration and aeration stop, Three types are prepared by changing the aeration treatment time for each time, and the aeration effect is ranked in order from the longest aeration treatment time per time, that is, the longest total aeration treatment time in the intermittent aeration process. In addition, from Example 18 to Example 4 described later.
The configurations shown in the first to eleventh embodiments can be applied to the device configurations according to the second to tenth embodiments.

FIG. 25 shows the effects of applying the operation control method according to the eighteenth embodiment to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 18, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 25A shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 25
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 18, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 19. FIG. 26 is a first embodiment of the present invention.
9 a prioritized aeration operation patterns 1C to 3C
Which are stored in the storage circuit 13. In this Example 19, the aeration operation pattern in which the aeration processing time and the aeration stopping time per one time are unchanged through the intermittent aeration processing process is used. In order to match with, the aeration time and the number of repetitions of aeration and aeration stop for each time are changed to prepare three types, and the aeration and aeration stop times are arranged in descending order of the number of aeration and aeration stop. The aeration effect is ranked in descending order of total length.

FIG. 27 shows the effects of applying the operation control method according to the nineteenth embodiment to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 19, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern has a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 27A shows time (day) on the horizontal axis.
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 27
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 19, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 20. FIG. 28 shows the second embodiment of the present invention.
0-ranked aeration operation patterns 1D to 3D
Which are stored in the storage circuit 13. In this Example 20, the aeration processing time per operation is unchanged throughout the intermittent aeration processing step, but the aeration operation pattern in which the aeration stop time gradually increases with the elapse of the processing time Three types of aeration and aeration stop repetitions are prepared without changing the treatment time. The aeration effect is in descending order of the number of aeration and aeration stop repetitions, that is, in the order of the total aeration treatment time in the intermittent aeration process. Has a high ranking.

FIG. 29 shows the effects of applying the operation control method according to this Example 20 to the inflow flow rate of sewage that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 20, the target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

In FIG. 29A, time (day) is plotted on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 29
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 20, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 21. FIG. 30 shows a second embodiment of the present invention.
Aerated operation patterns 1E to 3E according to No. 1
Which are stored in the storage circuit 13. In this Example 21, the aeration processing time per operation is unchanged through the intermittent aeration processing step, but the aeration operation time is such that the aeration stop time gradually increases as the processing time elapses. Without changing the number of repetitions, prepare three types by changing the aeration processing time per time, in order of increasing aeration processing time per time.
That is, the aeration effect is ranked in order of increasing total aeration processing time in the intermittent aeration processing step.

FIG. 31 shows the effect of applying the operation control method according to this embodiment to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. Also in this Example 21, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a low aeration effect was set to 2 mg / liter.

In FIG. 31 (a), the time (day) is plotted on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 31
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. In this Example 21 as well, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 22. 32 shows a second embodiment of the present invention.
Aerated operation patterns 1F to 3F related to No. 2
Which are stored in the storage circuit 13. In this Example 22, although the aeration processing time per operation is unchanged throughout the intermittent aeration processing step, the aeration operation pattern is such that the aeration stop time gradually increases as the processing time elapses, and the number of repetitions of aeration and aeration stop increases and decreases. Three types of aeration time and number of repetitions of aeration and aeration stop are prepared so that the total increase and decrease of the aeration processing time are consistent.
That is, the aeration effect is ranked in order of increasing total aeration processing time in the intermittent aeration processing step.

FIG. 33 shows the effects of applying the operation control method according to the twenty-second embodiment to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 22, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

In FIG. 33 (a), the time (day) is plotted on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 33
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 22, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 23. FIG. 34 shows a second embodiment of the present invention.
Aerated operation patterns 1G to 3G according to No. 3
Which are stored in the storage circuit 13. In this Example 23, the aeration stop time per operation is unchanged throughout the intermittent aeration process, but the aeration operation pattern is set in advance so that the aeration process time gradually decreases with the elapse of the processing time. Without changing the number of repetitions, prepare 3 types by changing the aeration processing time of each time,
The aeration effect is ranked in descending order of total aeration treatment time.

FIG. 35 shows the effect obtained when the operation control method according to the twenty-third embodiment is applied to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 23, the target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 35 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Fig. 35
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 24. FIG. 36 shows the second embodiment of the present invention.
Aerated operation patterns 1H to 3H according to No. 4
Which are stored in the storage circuit 13. In this Example 24, although the aeration stop time per operation is unchanged throughout the intermittent aeration process, the aeration operation pattern is set such that the aeration process time is gradually reduced with the lapse of the processing time, and the number of repetitions of aeration and aeration stop is increased and decreased. The aeration process time and the number of repetitions of aeration and aeration stop are changed to prepare three types so that the total increase and decrease of the aeration process time coincides with each other. The aeration effect is ranked in order of increasing total aeration processing time in the process.

FIG. 37 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. Also in this example, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a high aeration effect is -2 mg.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern with a low aeration effect was set to 2 mg / liter.

FIG. 37 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 37
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 24, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 25. 38 shows a second embodiment of the present invention.
Aerated operation patterns 1I to 3I according to No. 5
Which are stored in the storage circuit 13. In the twenty-fifth embodiment, the aeration process time is gradually reduced through the intermittent aeration process step, and the aeration stop time is gradually increased with the elapse of the process time. The aeration treatment time of each time is changed without changing the number of repetitions of, and three types are prepared, and the aeration effect is ranked in descending order of the total aeration treatment time.

FIG. 39 shows the effect obtained when the operation control method according to the twenty-fifth embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 25, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 39 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 39
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 26. FIG. 40 shows the second embodiment of the present invention.
Aerated operation patterns 1J to 3J according to No. 6
Which are stored in the storage circuit 13. In this example, through the intermittent aeration process, the aeration treatment time gradually decreases with the passage of the treatment time, and the aeration stop time gradually increases with the passage of the treatment time. In order to match the total increase / decrease in the aeration processing time, prepare three types by changing the aeration processing time and the number of repetitions of aeration and aeration stop at each time.
That is, the aeration effect is ranked in order of increasing total aeration processing time in the intermittent aeration processing step.

FIG. 41 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. Also in this example, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a high aeration effect is -2 mg.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern with a low aeration effect was set to 2 mg / liter.

FIG. 41A shows time (day) on the horizontal axis.
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 41
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 27. FIG. 42 shows the second embodiment of the present invention.
Aerated operation patterns 1K to 3K according to No. 7
Which are stored in the storage circuit 13. In this Example 27, the aeration operation pattern in which the aeration processing time and the aeration stop time change with the passage of the processing time through the intermittent aeration process is performed without changing the predetermined number of repetitions of aeration and aeration stop. Three types of aeration treatment time and aeration stop time are prepared so that the total aeration treatment time becomes longer as the pattern has a tendency to gradually decrease, and the aeration treatment time gradually increases as the treatment time elapses. From the pattern to the pattern in which the aeration treatment time gradually decreases with the lapse of the treatment time, that is, the aeration effect is ranked high in the descending order of the total aeration treatment time in the intermittent aeration treatment process.

FIG. 43 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. Also in this example, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a high aeration effect is -2 mg.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern with a low aeration effect was set to 2 mg / liter.

FIG. 43 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 43
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 27, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 28. FIG. 44 shows the second embodiment of the present invention.
8 related to aeration operation patterns 1L to 3L
Which are stored in the storage circuit 13. In this Example 28, the aeration operation pattern in which the aeration treatment time and the aeration stop time change with the passage of the treatment time through the intermittent aeration treatment process, the aeration and the aeration stop are repeated as the pattern having a strong tendency to gradually decrease the aeration treatment time. Three types of aeration treatment time and aeration stop time are prepared so that the total number of times and aeration treatment time increase, and the aeration treatment time is processed from the pattern in which the aeration treatment time gradually increases as the treatment time elapses. Higher aeration effects are ranked in order of a pattern that gradually decreases with the passage of time, that is, in the order of longer total aeration time in the intermittent aeration process.

FIG. 45 shows the effects of applying the operation control method according to the twenty-eighth embodiment to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 28, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 45A shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 45
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 28, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 29. FIG. 46 shows the second embodiment of the present invention.
9 a prioritized aeration operation pattern 1M to 3M
Which are stored in the storage circuit 13. In this example, the aeration stop time per change does not change during the intermittent aeration process, but the aeration operation pattern is such that the aeration process time changes with the elapse of the treatment time, and the aeration and aeration stop that are set in advance are repeated. Without changing the number of times, three types of aeration processing time are prepared by changing the aeration processing time each time so that the total aeration processing time becomes longer as the pattern has a strong tendency to gradually decrease the aeration processing time, and the aeration processing time gradually increases as the processing time passes. From such a pattern to a pattern in which the aeration treatment time gradually decreases as the treatment time elapses, that is, the aeration effect is highly ranked in the descending order of the total aeration treatment time in the intermittent aeration treatment process.

FIG. 47 shows the effect obtained when the operation control method according to the twenty-ninth embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 29, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 47 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 47
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 29, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 30. 48 shows a third embodiment of the present invention.
0-ranked aeration operation patterns 1N to 3N
Which are stored in the storage circuit 13. In this Example 30, the aeration stop time per change does not change throughout the intermittent aeration process, but the aeration operation pattern in which the aeration process time changes with the elapse of the processing time has a strong tendency to gradually decrease the aeration process time. The aeration process time is changed so that the total number of aeration and aeration stop repetitions and the aeration process time increase, and three types are prepared. The aeration effect is ranked high in order of a pattern in which the time gradually decreases as the processing time elapses, that is, in the order of increasing total aeration processing time in the intermittent aeration processing step.

FIG. 49 shows the effects of applying the operation control method according to this Example 30 to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 30, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect was −2 mg / liter, and a pattern having a low aeration effect was shifted. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 49 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 49
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this example, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 31. FIG. 50 shows the third embodiment of the present invention.
Aerated operation patterns 1O to 3O according to No. 1
Which are stored in the storage circuit 13. In this Example 31, the aeration processing time per operation is unchanged throughout the intermittent aeration processing step, but the aeration operation pattern is set so that the aeration stop time changes with the passage of the processing time. The number of repetitions is not changed, and three types are prepared by changing the aeration stop time for each time so that the total aeration process time becomes longer as the pattern has a tendency to gradually increase the aeration stop time, and the aeration stop time gradually decreases as the processing time elapses. From such a pattern to a pattern in which the aeration treatment time gradually increases as the treatment time elapses, that is, the aeration effect is highly ranked in the descending order of the total aeration treatment time in the intermittent aeration treatment process.

FIG. 51 shows the effects of applying the operation control method according to this Example 31 to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 31, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 51A shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 51
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 31, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 32. FIG. 52 shows the third embodiment of the present invention.
Aerated operation patterns 1P to 3P related to No. 2
Which are stored in the storage circuit 13. In this Example 32, the aeration processing time per operation is unchanged throughout the intermittent aeration processing step, but the aeration operation pattern in which the aeration stop time changes with the lapse of the processing time is a pattern with a strong tendency to gradually increase the aeration stop time. Aeration treatment is repeated from the number of repetitions of aeration and aeration to increase the total aeration treatment time. The aeration effect is highly ranked in order of a pattern in which the time gradually increases with the lapse of the processing time, that is, in the order of the total of the aeration processing times in the intermittent aeration processing step being long.

FIG. 53 shows the effect obtained when the operation control method according to the thirty-second embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 32, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern has a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

In FIG. 53 (a), the time (day) is plotted on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Fig. 53
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 32, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 33. 54 is a third embodiment of the present invention.
Aerated operation patterns 1Q to 3Q according to No. 3
Which are stored in the storage circuit 13. In this Example 33, the aeration operation pattern in which the aeration processing time and the aeration stop time per one time are unchanged through the intermittent aeration processing step is performed once without changing the total of the predetermined aeration processing times. Aeration treatment time, aeration, and number of times of aeration stop are changed to prepare three types.
The aeration effect is ranked higher in descending order of the number of repetitions of aeration stop.

FIG. 55 shows the effect obtained when the operation control method according to the embodiment 33 is applied to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 33, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 55 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 55
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 33, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 34. FIG. 56 shows prioritized aeration operation patterns 1R to 3 according to another embodiment of the sixth invention.
R is shown, and these are stored in the storage circuit 13. In this Example 34, the aeration processing time per operation is unchanged throughout the intermittent aeration processing process, but the aeration operation time is such that the aeration stop time gradually increases with the lapse of the processing time. Without changing
Three types of aeration treatment time and the number of repetitions of aeration and aeration stop are prepared, and three types of aeration and aeration stop are ordered in descending order of aeration effect.

FIG. 57 shows the effect obtained when the operation control method according to the 34th embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 34, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 57 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Fig. 57
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 34, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 35. FIG. 58 shows a third embodiment of the present invention.
Aerated operation patterns 1S to 3S according to No. 5
Which are stored in the storage circuit 13. In this Example 35, the aeration stop time per operation is unchanged through the intermittent aeration process, but the aeration operation time is gradually reduced with the lapse of the processing time. Without changing
Three types are prepared by changing the aeration processing time and the number of repetitions of aeration and aeration stop at each time, and the aeration effect is ranked in descending order of the number of repetitions of aeration and aeration stop.

FIG. 59 shows the effects of applying the operation control method according to this Example 35 to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 35, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 59 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 59.
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 35, it can be understood that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 36. FIG. 60 shows a third embodiment of the present invention.
Aerated operation patterns 1T to 3T according to No. 6
Which are stored in the storage circuit 13. In this Example 36, the aeration treatment time is gradually reduced through the intermittent aeration treatment step with the passage of the treatment time, and the aeration stop time is gradually increased with the passage of the treatment time. Without changing the total, three different types of aeration treatment time and the number of repetitions of aeration and aeration stop are prepared, and the aeration effect is ranked in descending order of the number of repetitions of aeration and aeration stop.

FIG. 61 shows the effect obtained when the operation control method according to this embodiment is applied to the sewage inflow rate that fluctuates as shown in FIG.
It is the result of simulation using the parameters shown in Table 1 and Table 2. Also in this Example 36, the target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water at the time of shifting to the pattern having a high aeration effect is −2.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a low aeration effect was set to 2 mg / liter.

FIG. 61 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 61
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 36, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 37. FIG. 62 shows a third embodiment of the present invention.
No. 7, ranked aeration operation patterns 1U to 3U
Which are stored in the storage circuit 13. In this Example 37, the aeration operation pattern in which the aeration processing time and the aeration stop time change with the lapse of the processing time through the intermittent aeration processing step does not change the total aeration processing time set in advance, and the aeration processing time is changed. The aeration process time and the aeration stop time of each time are changed so that three types are prepared so that the number of repetitions of the aeration and the aeration stop increases, and the aeration process time gradually increases as the treatment time elapses. From the pattern to the pattern in which the aeration processing time gradually decreases with the elapse of the processing time, that is, the aeration effect is highly ranked in the descending order of the number of repetitions of aeration and aeration stop.

FIG. 63 shows the effect of applying the operation control method according to the embodiment 37 to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this example, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a low aeration effect was set to 2 mg / liter.

In FIG. 63 (a), the time (day) is plotted on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Fig. 63
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 37, it can be seen that the aeration operation pattern is automatically changed with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 38. 64 shows a third embodiment of the present invention.
Aerated operation pattern 1V to 3V according to No. 8
Which are stored in the storage circuit 13. In this Example 38, the aeration stop time per operation is unchanged throughout the intermittent aeration process, but the aeration operation pattern is such that the aeration process time changes with the elapse of the process time. The aeration process time is gradually changed and the aeration process time is gradually increased with the lapse of the processing time. From such a pattern to a pattern in which the aeration processing time gradually decreases as the processing time elapses, that is, the aeration effect is highly ranked in the descending order of the number of repetitions of aeration and aeration.

FIG. 65 shows the effects of applying the operation control method according to this embodiment 38 to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 38, the target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 65 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. Figure 65
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 38, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 39. 66 shows a third embodiment of the present invention.
9 a prioritized aeration operation pattern 1W to 3W
Which are stored in the storage circuit 13. In this example, the aeration treatment time per one invariant throughout the intermittent aeration treatment process, the aeration operation pattern such that the aeration stop time changes with the passage of the treatment time Without changing the aeration stop time, three types are prepared by changing the aeration stop time each time so that the number of repetitions of aeration and aeration stop increases as the pattern has a strong tendency to gradually increase, and the aeration stop time gradually decreases as the processing time elapses. From such a pattern to a pattern in which the aeration processing time gradually increases as the processing time elapses,
That is, the aeration effect is ranked higher in descending order of the number of repetitions of aeration and aeration stop.

FIG. 67 shows the effects of applying the operation control method according to the embodiment 39 to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 39, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 67 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 67
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 39, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 40. 68 is a fourth embodiment of the present invention.
0-ranked aeration operation patterns 1X to 3X
Which are stored in the storage circuit 13. In Example 40, the aeration operation pattern and the aeration operation time in which the aeration operation time and the aeration stop time change with the lapse of the processing time are set to the predetermined aeration, the number of repetitions of the aeration stop, and the aeration processing time. Without changing the total, prepare three different types by gradually changing the aeration time.
The aeration effect is ranked in order from the pattern in which the aeration processing time gradually increases with the elapse of the processing time to the pattern in which the aeration processing time gradually decreases with the elapse of the processing time.

FIG. 69 shows the effects of applying the operation control method according to this embodiment 40 to the sewage inflow rate that fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 40, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 69 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 69
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 40, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 41. FIG. 70 shows a prioritized aeration operation pattern 1Y to 3 according to another embodiment of the seventh invention.
It indicates Y, and these are stored in the storage circuit 13. In this Example 41, the aeration stop time per operation is constant throughout the intermittent aeration process, but the aeration operation pattern is such that the aeration process time changes with the elapse of the processing time. The number of repetitions and the total of the aeration treatment time are not changed, and three types are prepared by changing the aeration time gradually and gradually. From the pattern that the aeration treatment time gradually increases with the passage of the treatment time, the aeration treatment time with the passage of the treatment time The aeration effect is ranked in order of decreasing pattern.

FIG. 71 shows the effects of applying the operation control method according to this Embodiment 41 to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this Example 41, the target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water at the time of shifting to the pattern having a high aeration effect is -2 mg / liter, and the pattern shifts to a pattern having a low aeration effect. The target value of the difference between the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water was set to 2 mg / liter.

FIG. 71 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 71
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 41, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 42. 72 shows a fourth embodiment of the present invention.
Aerated operation patterns 1Z to 3Z according to No. 2
Which are stored in the storage circuit 13. In this Example 42, although the aeration processing time per operation is unchanged throughout the intermittent aeration processing step, the aeration operation pattern in which the aeration stop time changes with the passage of the processing time is set in advance for aeration and aeration stop. The number of repetitions and the total aeration processing time are not changed, and three types are prepared by changing the gradual increase / decrease of the aeration stop time. From the pattern that the aeration stop time gradually decreases as the processing time elapses, the aeration processing time elapses. The aeration effect is ranked in order of increasing pattern.

FIG. 73 shows the effect of applying the operation control method according to the embodiment 42 to the sewage inflow rate which fluctuates as shown in FIG. It is the result of simulation using the parameters shown in Table 2. Also in this example, the target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to the pattern having a high aeration effect is −2.
The target value of the difference between the concentration of nitrate nitrogen in the treated water and the concentration of ammonia nitrogen in the treated water at the time of shifting to a pattern having a low aeration effect was set to 2 mg / liter.

FIG. 73 (a) shows time (day) on the horizontal axis,
3 is a graph showing the concentration of ammonia nitrogen (solid line) and the concentration of nitrate nitrogen (broken line) in the treatment tank 1 immediately before the start of the discharging step, with the nitrogen concentration (mg / liter) as the vertical axis. FIG. 73
(B) is a graph showing a change in the selected aeration operation pattern with time (day) as the horizontal axis and the number of the aeration operation pattern as the vertical axis. Also in this Example 42, it can be seen that the aeration operation pattern automatically changes with respect to the fluctuation of the inflow flow rate of the sewage, and the nitrate nitrogen concentration in the treated water and the ammonia nitrogen concentration in the treated water are well reduced.

Example 43. In the above-mentioned Examples 1 to 42, the operation schedule of aeration and aeration stop in the intermittent aeration process step is set according to the elapsed time after the start of the process, but it is set according to the integrated amount of sewage flowing in after the start of the process. Also, the same effect as that of the above-described embodiment is obtained.

Example 44. In the above-mentioned Examples 1 to 43, the aeration operation pattern was defined for the case where the sewage almost uniformly flows in during the intermittent aeration treatment process, but the aeration treatment time and the aeration stop time may be adjusted appropriately according to the inflow situation of the sewage. In this case, in addition to the effect of the above-mentioned embodiment, there is an effect that the quality of treated water can be controlled more finely.

Example 45. In the above-mentioned Examples 1 to 44, the system for displaying the selection result of the aeration operation pattern to the operation manager of the intermittent aeration type activated sludge method water treatment device was constructed.
If the output signal of the selection result is directly input to the controller of the aeration blower, in addition to the effects of the above embodiment, there is an effect that the burden on the operation manager can be further reduced.

Example 46. In the above-described Examples 1 to 45, the time continuous analog type is used, but even if the time discontinuous analog type or digital type is used, the same effect as the above example can be obtained.

Example 47. In the above Examples 1 to 46, the case of removing nitrogen was described, but other contaminants,
For example, it can be applied to remove organic substances or phosphorus.

[0244]

The operation control method of the intermittent aeration type activated sludge method water treatment device according to the first aspect of the present invention provides at least two or more operation patterns which define aeration and aeration in the intermittent aeration process. Based on at least the total aeration time, the number of repetitions of the aeration process, and the length of each aeration process,
Prioritize from the pattern with high aeration effect to the pattern with low aeration effect, and process water quality or plant value,
For example, the actual aerobic time when the dissolved oxygen concentration exceeds a predetermined value in the intermittent aeration treatment process, or the substantial anaerobic time when the dissolved oxygen concentration is less than the predetermined value,
Alternatively, the treatment index of the treated water is calculated by a predetermined arithmetic expression from the concentration of nitrate nitrogen and the concentration of ammonia nitrogen in the treated water, and the calculated value is compared with the predetermined target value of the treatment index. , When it is detected that the amount of aeration to be input is insufficient depending on the magnitude of this comparison result, a pattern with a higher aeration effect than the currently used aeration operation pattern is selected, and the amount of aeration to be input is excessive. When this is detected, the aeration operation pattern is changed according to a predetermined order so that a pattern with a lower aeration effect than the currently used aeration operation pattern is selected , and intermittent exposure is performed.
The dissolved oxygen concentration in the aeration tank in the gas treatment process is set in advance.
Of time above and below the dissolved oxygen concentration standard value
Since the time ratio is used as the treatment index , the aeration treatment time and the aeration stop time can be appropriately set,
The effect that the pollutant component in the wastewater can be satisfactorily removed and a good water purification treatment can be realized is achieved.

[0245]

[0246]

[0247]

The operation control method of the intermittent aeration type activated sludge method water treatment device according to claim 2 of the present invention is the intermittent aeration process treatment.
At least two or more defined aeration and cessation of aeration
Operation pattern, at least total aeration time, aeration process
The number of repetitions and the length of each aeration treatment time
Predict from patterns with high aspiration effects to patterns with low aeration effects
Prioritized, treated water quality or plant value, eg
For example, the dissolved oxygen concentration is set in advance in the intermittent aeration process.
The actual aerobic time exceeding the specified value or the dissolved oxygen concentration
The actual anaerobic time when the degree is less than the predetermined value,
Or Nitrate Concentration and Ammonia Nitrogen in Treated Water
The treated water is calculated according to a predetermined calculation formula based on the elementary concentration.
The processing index is calculated, and the calculated value is set in the predetermined processing.
The comparison result with the target value of the
When it detects that the amount of aeration to be input is insufficient
Has a higher aeration effect than the aeration operation pattern currently used.
Select an appropriate pattern and, on the contrary, input an excessive amount of aeration.
If this is detected, the aeration operation pattern currently used
Aeration rate should be selected to select a pattern with a lower aeration effect than
The transfer pattern is changed according to a predetermined order, and the difference between the accumulated time of the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is higher and lower than the predetermined dissolved oxygen concentration reference value is used as the treatment index. Therefore, the aeration processing time and aeration stop time can be set appropriately,
The effect that the pollutant component in the wastewater can be satisfactorily removed and a good water purification treatment can be realized is achieved.

[0249]

[0250]

The operation control method of the intermittent aeration type activated sludge method water treatment device according to claim 3 of the present invention is the operation control method of the intermittent aeration type activated sludge method water treatment device according to claim 1 , wherein Since the target value of the treatment index is set in the range of 1/10 to 10 times the ratio of the denitrification rate of activated sludge to the nitrification rate, the aeration treatment time and aeration stop time can be set appropriately, and the sewage The effect of being able to satisfactorily remove the pollutant components therein and realize a favorable water purification treatment is achieved.

[0252] Operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to claim 4 of the present invention, in the operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to claim 2, the difference in integration time Since the target value of the treatment index is set in the range of -1 hour to 1 hour, the aeration treatment time and the aeration stop time can be appropriately set, and the pollutant components in the wastewater can be removed well and the aeration treatment time can be improved. The effect that water purification processing can be realized is achieved.

[0253] Operation control method of the intermittent aeration type activated sludge process water treatment apparatus according to a fifth aspect of the invention, according claim 1
In the operation control method of the intermittent aeration type activated sludge method water treatment device according to any one of the items up to item 4 , the predetermined dissolved oxygen concentration reference value is set to a range of 0 to ₂ mg-O ₂ / liter. Further, it is possible to appropriately set the aeration treatment time and the aeration stop time, and it is possible to satisfactorily remove the pollutant components in the wastewater and realize a good water purification treatment.

[0254]

[0255]

[0256]

[0257]

[0258]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an aeration operation pattern used in a computer simulation that has led to the discovery of the first law of the present invention.

FIG. 2 is a graph showing the result of computer simulation that led to the discovery of the first law of the present invention.

FIG. 3 is a graph showing the results of computer simulation that led to the discovery of the second law of the present invention.

FIG. 4 is a graph showing the results of computer simulation that led to the discovery of the third law of the present invention.

FIG. 5 is a graph showing the results of computer simulation that led to the discovery of the fourth law of the present invention.

FIG. 6 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to Example 1 of the present invention.

FIG. 7 is a flowchart showing the processing steps of the operation control method of the intermittent aeration type activated sludge method water treatment device according to the first embodiment of the present invention.

FIG. 8 is a graph showing a computer simulation result of an operation control method of the intermittent aeration type activated sludge method water treatment device according to Example 1 of the present invention.

FIG. 9 is a graph showing fluctuations in the inflow rate of sewage used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to an example of the present invention.

FIG. 10 is an explanatory diagram showing an aeration operation pattern used for a computer simulation of an operation control method of the intermittent aeration type activated sludge method water treatment device according to the first embodiment of the present invention.

FIG. 11 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to a second embodiment of the present invention.

FIG. 12 is a flowchart showing processing steps of an operation control method for an intermittent aeration type activated sludge method water treatment apparatus according to Example 2 of the present invention.

FIG. 13 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to Example 3 of the present invention.

FIG. 14 is a flow chart showing processing steps of an operation control method of an intermittent aeration type activated sludge method water treatment apparatus according to Example 3 of the present invention.

FIG. 15 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to Example 4 of the present invention.

FIG. 16 is a flowchart showing processing steps of an operation control method for an intermittent aeration type activated sludge method water treatment apparatus according to Example 4 of the present invention.

FIG. 17 is a block diagram showing an intermittent aeration type activated sludge method water treatment device according to a fifth embodiment of the present invention.

FIG. 18 is a flowchart showing the processing steps of the operation control method for the intermittent aeration type activated sludge method water treatment device according to the fifth embodiment of the present invention.

FIG. 19 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to Example 6 of the present invention.

FIG. 20 is a flowchart showing processing steps of an operation control method for an intermittent aeration type activated sludge method water treatment apparatus according to Example 6 of the present invention.

FIG. 21 is a configuration diagram showing an intermittent aeration type activated sludge method water treatment device according to a twelfth embodiment of the present invention.

FIG. 22 is a flowchart showing processing steps of an operation control method for an intermittent aeration type activated sludge method water treatment apparatus according to Example 12 of the present invention.

FIG. 23 is a graph showing a computer simulation result of an operation control method of an intermittent aeration type activated sludge method water treatment device according to Example 12 of the present invention.

FIG. 24 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to Example 18 of the present invention.

FIG. 25 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 18 of the present invention.

FIG. 26 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to Example 19 of the present invention.

FIG. 27 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 19 of the present invention.

FIG. 28 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a twentieth embodiment of the present invention.

FIG. 29 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 20 of the present invention.

FIG. 30 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a twenty-first embodiment of the present invention.

FIG. 31 is a graph showing a computer simulation result of an operation control method of the intermittent aeration type activated sludge method water treatment device according to Example 21 of the present invention.

FIG. 32 is an explanatory diagram showing an aeration operation pattern used for a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a twenty second embodiment of the present invention.

FIG. 33 is a graph showing a computer simulation result of an operation control method of the intermittent aeration type activated sludge method water treatment device according to Example 22 of the present invention.

FIG. 34 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a twenty-third embodiment of the present invention.

FIG. 35 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 23 of the present invention.

FIG. 36 is an explanatory diagram showing an aeration operation pattern used for a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a twenty-fourth embodiment of the present invention.

FIG. 37 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 24 of the present invention.

FIG. 38 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a twenty-fifth embodiment of the present invention.

FIG. 39 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 25 of the present invention.

FIG. 40 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a twenty-sixth embodiment of the present invention.

FIG. 41 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 26 of the present invention.

FIG. 42 is an explanatory diagram showing an aeration operation pattern used for a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a twenty-seventh embodiment of the present invention.

FIG. 43 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 27 of the present invention.

FIG. 44 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a twenty-eighth embodiment of the present invention.

FIG. 45 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 28 of the present invention.

FIG. 46 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to Example 29 of the present invention.

FIG. 47 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 29 of the present invention.

FIG. 48 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a thirtieth embodiment of the present invention.

FIG. 49 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 30 of the present invention.

FIG. 50 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a thirty-first embodiment of the present invention.

FIG. 51 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 31 of the present invention.

FIG. 52 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a thirty-second embodiment of the present invention.

FIG. 53 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 32 of the present invention.

FIG. 54 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a thirty-third embodiment of the present invention.

FIG. 55 is a graph showing a computer simulation result of an operation control method of the intermittent aeration type activated sludge method water treatment device according to Example 33 of the present invention.

FIG. 56 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a thirty-fourth embodiment of the present invention.

FIG. 57 is a graph showing a computer simulation result of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a thirty-fourth embodiment of the present invention.

FIG. 58 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a thirty-fifth embodiment of the present invention.

FIG. 59 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 35 of the present invention.

FIG. 60 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of an intermittent aeration type activated sludge method water treatment device according to a thirty-sixth embodiment of the present invention.

FIG. 61 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 36 of the present invention.

FIG. 62 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 37 of the present invention.

FIG. 63 is a graph showing a computer simulation result of an operation control method for an intermittent aeration type activated sludge method water treatment device according to Example 37 of the present invention.

FIG. 64 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to an example 38 of the present invention.

FIG. 65 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 38 of the present invention.

FIG. 66 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a 39th embodiment of the present invention.

FIG. 67 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 39 of the present invention.

FIG. 68 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to a fortieth embodiment of the present invention.

FIG. 69 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to the fortieth embodiment of the present invention.

FIG. 70 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method of the intermittent aeration type activated sludge method water treatment device according to the example 41 of the present invention.

71 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 41 of the present invention. FIG.

FIG. 72 is an explanatory diagram showing an aeration operation pattern used in a computer simulation of an operation control method for an intermittent aeration type activated sludge method water treatment device according to Example 42 of the present invention.

FIG. 73 is a graph showing a computer simulation result of an operation control method for the intermittent aeration type activated sludge method water treatment device according to Example 42 of the present invention.

FIG. 74 is a configuration diagram showing a conventional intermittent aeration type activated sludge method water treatment device.

FIG. 75 is an explanatory diagram showing a method of operating a conventional intermittent aeration type activated sludge method water treatment device.

[Explanation of symbols]

1 treatment tank, 2 aeration blower, 4 air diffuser, 7 nitrate nitrogen concentration meter, 8 ammonia nitrogen concentration meter, 9, 2
3, 25, 27, 32, 33 arithmetic unit, 10 comparison arithmetic unit, 11, 14, 15, 18, 19, 24, 28, 3
5, 39 setting device, 12 display device, 13 memory circuit,
16 controller, 17 input / output circuit, a, e, f
Piping, 7a, 8a, 9a, 10a, 11a, 12a, 1
3a, 14a, 15a, 16a, 17a signal line, 20
Dissolved oxygen concentration meter, 21 flow meter, 22 water level meter, 3
6, 37 accumulator, 38, 40 counter.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahiro Shimaoka Inventor Masahiro Wadazaki-cho 1-2-2, Kobe Hyogo-ku Kobe Mitsubishi Electric Co., Ltd. (56) Reference JP-A-5-309389 (JP, A) JP-A-2-284697 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C02F 3/12-3/34

Claims (5)

(57) [Claims] 1. At least two or more operation patterns defining aeration and aeration stop in the intermittent aeration process, based on at least the total aeration time, the number of times of the aeration process, and the length of each aeration process, Preliminarily rank in descending order of aeration effect, compare the treatment index obtained from the treated water quality or plant value by a predetermined arithmetic expression, and the predetermined target value of the treatment index, and compare the results. The operation pattern is changed according to the ranking according to the size of the above, and the dissolved oxygen concentration in the aeration tank in the intermittent aeration process is
Time higher and lower than predetermined dissolved oxygen concentration standard value
An operation control method of an intermittent aeration type activated sludge method water treatment device, characterized in that an integrated time ratio of time is used as the treatment index . 2.Aeration and aeration stop in the intermittent aeration process
Stop at least two driving patterns
Total at least aeration time, number of aeration process repetitions, each exposure
Based on the length of air treatment time, predict in descending order of aeration effect.
Therefore, prioritize, Predetermined arithmetic expression from treated water quality or plant value
And the processing index determined by
Comparing with the target value of the physical index, The driving pattern is ranked according to the magnitude of this comparison result.
Change according to The dissolved oxygen concentration in the aeration tank in the intermittent aeration process is
Time higher and lower than predetermined dissolved oxygen concentration standard value
TemporalThe difference between the integrated times is used as the processing index.
DoOperation control method for intermittent aeration type activated sludge water treatment equipment. 3. The target value of the processing index of the cumulative time ratio is utilized.
1/10 to 10 times the ratio of denitrification rate and nitrification rate of activated sludge
The operation control method of the intermittent aeration type activated sludge method water treatment apparatus characterized by setting to a range . 4. A target value of the processing index for the difference in integrated time
-Contract characterized by setting in the range of 1 hour to 1 hour
EQUATION 2 The operation control method of the intermittent aeration type activated sludge method water treatment equipment. 5. A predetermined dissolved oxygen concentration standard value is set to 0.
It is characterized in that it is set in the range of up to 2 mg / liter.
An operation control method for an intermittent aeration type activated sludge method water treatment device according to any one of claims 1 to 4 .