JP2000015279A - Continuous method for treating drainage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To respond to the change of the quantity of inflow in advance by a method in which the quantity of introduced drainage is measured continuously, accumulated values of the measuring results of every time, day, month, and year are calculated, the variation quantities of every period are averaged and converted into a pattern, and the obtained variation pattern is used to control each process of drainage treatment. SOLUTION: In a continuous method for treating drainage whose inflow quantity changes, the inflow quantity is measured by a flow meter, the results of every period such as time, day, and others are accumulated and stored in a personal computer and others. The accumulated values are averaged every given period and stored as an inflow pattern. By the stored pattern, control values of every minute, hour, and day are output to be used to control each process of drainage treatment. For example, a variation pattern is used to control the extraction quantity of sludge from a sludge circulation tank 7 to a sludge concentration tank 11. The quantity of sludge to be extracted is determined by the total quantity per day of the inflow quantity converted into a pattern, the operation times of a sludge extraction pump 25 and others are determined, and sludge is extracted from the sludge circulation tank 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating sewage, and more particularly to a method for continuously treating sewage with fluctuations in flow such as sewage, agricultural settlement drainage, combined clarification tanks, and factory drainage.

[0002]

2. Description of the Related Art Conventionally, the treatment of sewage such as sewage and industrial wastewater is controlled by setting a constant numerical value based on an average treatment amount for one day or a longer period regardless of inflow load fluctuation. Alternatively, the inflow load is measured by a flow meter, and the flow is controlled by a value that eventually follows the inflow amount. In the control by the average constant numerical value, for the fluctuation of the inflow amount in each period, the processing conditions, the fluctuation value of the chemical injection amount and the like can not be fully controlled,
The effect of fluctuations in the amount of inflow appeared in the treated water, resulting in deterioration of water quality. In addition, by measuring the inflow load with a flow meter and controlling the amount immediately following the flow, it is not possible to grasp the subsequent fluctuations and daily trends. , Can not control.

Conventionally, the amount of excess sludge withdrawn is conventionally determined by the change in MLSS in an aeration tank or the amount of sludge in a concentration tank or a concentrated sludge storage tank for a certain period of time. However, in the case of sewage with relatively uniform inflow water quality, fluctuations in the amount of inflow caused changes in the amount of surplus sludge generated, and it was not possible to cope with such changes. Also,
Conventionally, in treating organic sewage such as sewage, the odor emitted by the organic sewage itself and the odor caused by the anaerobic decomposition of sludge generated in the treatment system during the stagnation are caused. The occurrence of odor was observed, and the odor generated in each tank was considerably strong, resulting in deterioration of the working environment. Therefore, as an odor prevention measure, it is necessary to prevent and deodorize odors from sewage and sludge in a liquid state while treating organic sewage such as sewage. Needed to be properly controlled.

[0004]

SUMMARY OF THE INVENTION In view of the above prior art, the present invention makes it possible to pattern fluctuations in daily inflows, predict fluctuations in inflows, and respond to fluctuations in inflows in advance. It is another object of the present invention to provide a method for continuously treating wastewater that can be finely controlled.

[0005]

In order to solve the above problems, the present invention provides a method for continuously treating sewage having a variable amount of inflow, by continuously measuring the amount of sewage flowing into a treatment step, Calculate the integrated value of the measured result every hour, day, month, and year, average and pattern the fluctuation amount for each period, and use the obtained fluctuation pattern for control of each process of sewage treatment. It is a continuous treatment method of sewage which is a feature. In the processing method, using the obtained fluctuation pattern, predicting a predicted amount of fluctuation in inflow of sewage in advance, and using the predicted value to control processing steps that need to be controlled to follow the fluctuation amount. Can be.

Further, the fluctuation pattern obtained by the present invention is:
It can be used as follows. (1) Using the batch activated sludge method for treating sewage in fixed amounts, predict the total amount of sewage inflow that is expected by averaging in advance for the day and calculate the number of times of operation of the batch tank on the day based on the estimated amount. Control. (2) Predict the total daily sewage inflow that is expected to be averaged in advance and used in the biological treatment process for the day, and control the water supply to the biological treatment process at a constant rate throughout the day based on the predicted value. I do. (3) The chemical injection amount is controlled based on a sewage inflow amount time variation pattern which is used for wastewater treatment in which the amount of chemical injection is changed according to the amount of inflow of wastewater.

(4) Predict the total amount of inflow of sewage per day which is used for biological treatment of sewage and averaged in advance on the day, and controls the amount of excess sludge withdrawn on that day based on the predicted amount. The amount of concentrated sludge withdrawn in the sludge concentration step is controlled according to the expected daily amount of inflow of wastewater and / or the amount of excess sludge withdrawn, and the operation time of the dehydrator is controlled based on the amount of concentrated sludge withdrawn. . (5) The humus used for biological treatment of sewage, which predicts the inflow of sewage according to the time variation pattern of inflow of sewage predicted in advance, and treats the separated sludge returned to the sewage inflow section based on the predicted amount. The amount of the separation liquid and / or sludge containing the quality is controlled.

[0008]

Next, the processing method of the present invention will be described in detail. First, the patterning procedure will be described. (1) The inflow rate is measured by an inflow flow meter, and the measured inflow rate is integrated for a period such as minutes, hours, or days, and stored by a personal computer or the like. (2) The above integrated value is averaged at regular intervals and stored as an inflow pattern. (3) A control value for each minute, hour, and day is output based on the stored pattern, and is used for controlling the amount of chemical injection and the like. (4) By storing inflow fluctuations for one year, a unique day pattern is separately stored. (5) The special day indicates an increase or decrease in the inflow of sewage, factory drainage, and the like at the tray, at the end of the year, and at the beginning of the year. (6) Using the pattern of the unique day for control, predicting and controlling the fluctuation of the inflow amount.

Next, a specific patterning method and a method of using the created pattern will be described. 1) The hardware configuration is one of the following. (1) Sequencer + touch panel (2) Personal computer 2) Basic functions (1) This device is common to all water treatment facilities. (2) Store the integrated amount of inflow of sewage as follows (flow rate logging function). a. Daily fluctuation (fluctuation every hour) Data amount 24 data x 365 days b. Weekly fluctuation (fluctuation every day and every day of the week) Data amount 7 pieces × 52 weeks c. Annual fluctuation (monthly fluctuation) Data volume 1 piece x December d. Annual total data volume 1 piece x 1 year e. The minimum data unit to be stored and stored is an hourly integrated flow rate. 1 year = 1 hour x 24 hours x 365 days = 8760 unit data

(3) The integrated value is calculated by one of the following (integrating function). Basically, it is assumed that the integration is within the a-type. a. Electromagnetic flow meter of the flow pulses (one pulse =? M ³⁾ Type integrates internally. b. Input the hourly integrated flow rate from the external integrator. (4) Average pattern of flow rate fluctuation (learning function) a. Daily fluctuation (1 week pattern) The daily fluctuation is patterned by averaging the flow rate integrated value for each hour in the immediately preceding week. (In this case, the day of the week is not considered.) B. Daily variation (4 week pattern) The daily variation for each day of the week is patterned by averaging the flow rate integrated value for each hour of the immediately preceding 4 weeks for each day of the week. c. Weekly Fluctuation (4 Week Pattern) The flow rate integrated value change for each day of the week is patterned by averaging the flow rate integrated value for each day of the last 4 weeks for each day of the week.

(5) Output of flow rate fluctuation pattern (external control function) a. Output contents (The accumulated storage flow value shown below indicates the pattern processed.) Output by (storage time flow integrated value x proportional set value) Example of use Separation liquid such as control of chemical injection amount based on raw water flow rate Output based on the determination of the amount (Output based on the integrated value of the stored daily flow rate x Proportional set value) Example of use) Calculate and output the amount of extra sludge withdrawal per day based on the amount of raw water inflow per day. Output the basis for determining the amount of batch sludge withdrawal and withdrawal time Example of alarm setting output based on output of dehydrator operation time determination (accumulated storage flow rate) Example of application to waiting (judgment of operation start such as batch) Example of alarm setting output based on (accumulated storage flow rate) 1 Judgment of the number of operations, such as batches, based on the amount of Nihara water inflow The adjustment of the outflow of the flow control pump (to minimize daily load fluctuations in the water treatment system)

(6) Manual Input of Flow Fluctuation Pattern The flow fluctuation pattern can be set manually. (7) Preservation of fixed flow fluctuation pattern and its output a. The fixed flow fluctuation pattern includes sewer characteristics, sightseeing characteristics,
Classify according to life pattern characteristics and the like. b. The above-mentioned classification characteristics are selected, and an output based on the initial fixed flow rate fluctuation pattern is performed. c. After the processing station flow rate data is stored and the flow rate fluctuation pattern of the processing station is confirmed, the control output shifts from the fixed flow rate fluctuation pattern to the recognized flow rate fluctuation pattern. (8) Unique discharge fluctuation pattern (Bon, living, sightseeing season,
Storage of special weekends and holidays and output by them a. The day when the specific flow rate variation pattern is used is manually set in advance. b. Set a unique date using the calendar.

Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a flowchart illustrating the processing method of the present invention. In FIG. 1, W indicates a sewage treatment system, C indicates a sludge treatment system, and the sewage treatment system W includes a pretreatment step 1, a flow control tank 2, an anaerobic filter tank 3, a contact aeration tank 4, a sedimentation tank 5, It has a disinfection tank 9, and the sludge treatment system C includes a sludge receiving tank 6, a sludge circulation tank 7, a sludge contact tank 8, a separation liquid tank 10, and a sludge concentration tank 1.
1 and a sludge storage tank 12, and 25 and 26 indicate pumps. The organic sewage 16 is introduced into the pretreatment step 1 while measuring the amount of inflow, and is mixed with a separation liquid and / or sludge 21 described below to remove coarse substances, remove sand and the like, and perform pretreatment such as aeration. After performing, it is introduced into the flow control tank 2.

From the flow control tank 2, a certain amount of sewage flows into an anaerobic filter tank 3 for biofilm treatment under anaerobic conditions, and is mixed with treated water 20 returned from a contact aeration tank 4 at the subsequent stage. , Is partially denitrified, flows into the contact aeration tank 4, and is aerobically biologically treated. Part of the treated water in the contact aeration tank 4 is 20
Is returned to the anaerobic filter tank 3 and the remainder is introduced into the sedimentation tank 5. The treated water separated in the sedimentation tank 5 is disinfected in the disinfection tank 9 and discharged 17. On the other hand, the sludge 19 settled in the settling tank 5 is introduced into the sludge receiving tank 6 together with the sludge 18 withdrawn from the anaerobic filter bed tank 3. The sludge introduced into the sludge receiving tank 6 is sent out to a sludge circulating tank 7, and the sludge is circulated between the sludge circulating tank 7 and the sludge contact tank 8, and is brought into contact with the filler containing humus in the sludge contact tank 8. A part of the sludge in the sludge circulation tank 7 flows out to the separation liquid tank 10, and the other part is introduced into the sludge concentration tank 11 to concentrate the sludge, and then stored in the sludge storage tank 12.

Here, the sludge circulation tank 7 to the sludge concentration tank 11
The amount of sludge drawn out can be determined using the variation pattern described above. The sludge withdrawal amount is determined based on the total daily amount of the patterned inflow amount, and the operation time of the sludge withdrawal pump 25 and the like is determined, whereby the sludge is withdrawn from the sludge circulation tank 7. In the case where the extracted excess sludge is directly dewatered, the operation time of the dehydrator is determined. The sludge that has flowed into the separation liquid tank 10 is settled and separated from the sludge and returned to the pretreatment step 1 together with a separation liquid containing humus, which is a supernatant liquid, or as it is without separation, or together with the separated sludge. The return 21 to the pretreatment step 1 can be performed by controlling the operation time or the number of rotations of the return pump 26 for the separated liquid and / or sludge using the above-mentioned fluctuation pattern of the inflow amount.

FIG. 2 shows another flow configuration diagram of the processing method of the present invention. In FIG. 2, the difference from FIG. 1 lies only in the sewage treatment system W, and there is no difference in the return of the sludge treatment system C and the separated liquid and / or sludge. In FIG. 2, the sewage treatment system W
Biological treatment process is performed in batch tanks 22a and 22b,
The introduction of sewage from the flow control tank 2 to the batch tank is performed in time series to the plurality of batch tanks 22a and 22b, and the batch tanks 22a and 22b are
Sludges 23a and 23b separated from 2b are respectively introduced into sludge receiving tank 6, and sludge treatment is performed in the same manner as in FIG. on the other hand,
The supernatant water in the batch tank flows into the watering pump tank 24 as treated water, and then is introduced into the disinfecting tank 9 where it is discharged 17 after disinfection. The batch tank can be used in only one tank.
2b and 23b are not required.

FIG. 3 shows a controller configuration diagram using the inflow pattern. The inflow amount signal 37 is input to the personal computer 31 by an analog or pulse signal,
Calculation processing is stored. A control output based on the stored data is output from the personal computer 31 to the sequencer 33, and the sequencer 33 outputs an operation control signal for each device based on the output. Thereafter, the power control panels 35 and 36 receive the output of the sequencer 33 and operate the respective devices. If the amount of stored data is small, the personal computer 31
It is also possible to impose the function of. The data control information is displayed on the touch panel display unit 32, and necessary manual input set values and the like are input from the touch panel display unit 32. Automatic conditions, alarm signals, and the like 38 are input to the personal computer 31 or the sequencer 33 and used for the operation control.

[0018]

According to the present invention, the following effects can be obtained. (1) Fluctuation of the inflow amount is predicted, and a response to the fluctuation of the inflow amount can be taken in advance. (2) It is possible to respond finely to fluctuations in the amount of inflow, and to prevent deterioration of water quality. (3) By storing and using a specific inflow pattern in advance, it is possible to cope with a fluctuation of a specific inflow amount which is not seen in daily fluctuation. (4) By using a fluctuation pattern for controlling the amount of excess sludge withdrawn, fluctuations in inflow load can be appropriately managed, and deterioration of water quality can be prevented and maintenance can be easily performed. (5) By using a fluctuation pattern for controlling the return amount of the separation liquid containing humus and / or sludge to the wastewater receiving tank,
Odor can be prevented constantly and stably.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a processing method according to the present invention.

FIG. 2 is a flowchart showing another example of the processing method of the present invention.

FIG. 3 is a configuration diagram of a controller using an inflow pattern.

[Explanation of symbols]

1: Pretreatment step, 2: Anaerobic filter bed tank, 3: Contact aeration tank,
4: sedimentation tank, 5: disinfection tank, 6: sludge receiving tank, 7: sludge circulation tank, 8: sludge contact tank, 9: disinfection tank, 10: separation liquid tank, 1
1: Sludge thickening tank, 12: Sludge storage tank, 16: Sewage, 1
7: treated water, 22a, 22b: batch tank, 25, 26: pump, 31: personal computer, 32: touch panel display, 33: sequencer, 34: manual input control value, 35: power control panel, 36: power control Panel, 37: Inflow signal, 38: Automatic input control value C: Sludge treatment system W: Sewage treatment system

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tokuaki Itoi 1-10-14, Hamamatsucho, Minato-ku, Tokyo Within the Japan Association of Agricultural Village Drainage (72) Inventor Kazuhiro Shinoka 1-chome, Hamamatsucho, Minato-ku, Tokyo No. 10-14 Japan Association of Agricultural Village Drainage Association (72) Inventor Takayuki Kada 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Akira Ichihara, Asahi-cho, Ota-ku, Tokyo No. 11 F term in EBARA CORPORATION (Reference) 4D028 AA03 AC00 BB01 BC01 BE08 CA00 CA11 CA12 CB03 CC01 CD08

Claims (9)

[Claims] In a method for continuously treating sewage having a variable inflow, the amount of sewage flowing into a treatment step is continuously measured, and the measured result is integrated into an hourly, daily, monthly, and yearly integrated value. A continuous sewage treatment method comprising calculating, averaging and patterning the amount of change in each period, and using the obtained change pattern for controlling each process of sewage treatment. 2. Using the obtained fluctuation pattern, predict a predicted fluctuation amount of inflow of sewage in advance, and use the predicted value to control a processing step which needs to be controlled to follow the fluctuation amount. The continuous treatment method for sewage according to claim 1, wherein: 3. Using the obtained fluctuation pattern in a batch activated sludge method for treating sewage in fixed amounts, predicting the total amount of sewage inflow that is expected to be averaged in advance for the day and predicting the estimated amount. The continuous treatment method for sewage according to claim 1, wherein the number of operations of the batch tank on the day is controlled based on the following. 4. The obtained fluctuation pattern is used in a biological treatment process for sewage to predict the total amount of daily sewage inflow that is predicted and averaged in advance for that day, and the biological treatment process is performed throughout the day based on the predicted value. The continuous treatment method for sewage water according to claim 1, wherein the sewage water is controlled to be supplied at a constant amount. 5. The method according to claim 1, wherein the obtained fluctuation pattern is used for treating wastewater in which a chemical injection amount is changed in accordance with a wastewater inflow amount.
2. The continuous treatment method for sewage according to claim 1, wherein the chemical injection amount is controlled based on a sewage inflow amount time variation pattern that is predicted in advance. 6. The obtained fluctuation pattern is used for biological treatment of sewage water, and the average amount of sewage inflow is predicted by averaging in advance on the day to predict the total amount of sewage inflow per day based on the predicted amount. 2. The method for continuously treating wastewater according to claim 1, wherein 7. The expected daily sewage inflow and / or
7. The method for continuously treating wastewater according to claim 6, wherein the amount of concentrated sludge withdrawn in the sludge concentration step is controlled according to the amount of excess sludge withdrawn. 8. The continuous treatment method for sewage according to claim 6, wherein the operation time of the dehydrator is controlled based on the amount of concentrated sludge to be withdrawn. 9. The obtained fluctuation pattern is used for biological treatment of sewage, and the inflow of sewage is predicted based on a time fluctuation pattern of the inflow of sewage predicted in advance, and the sewage inflow is estimated based on the predicted amount. The continuous treatment method for sewage water according to claim 1, wherein a return amount of a separated liquid and / or sludge containing humus obtained by treating the separated sludge returned to the section is controlled.