JP2011230069A - Aeration operation control system and aeration operation control method for sewage treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the operation of an aeration blower so that the activity of microorganisms in an aeration tank is optimum according to the circumstances of domestic waste water.SOLUTION: A water temperature sensor 240 detects a water temperature of sewage in an aeration tank 160. A pH sensor 480 detects pH of treated water which has been cleaned by microorganisms. By making an operation ratio setting part 340 set, in a ratio pattern storage part 360, an operation ratio that is a ratio of a stopping time to an operation time in intermittently operating an aeration blower 220, based on the detected water temperature and pH; the intermittent operation of the aeration blower 220 is controlled according to the pH value and water temperature of treated water that are results of many factors, such as the circumstances of domestic waste water including quantity of sewage flowing into the aeration tank 160, chemical properties and water temperature and the activity of microorganisms decomposing organisms included in sewage.

Description

  The present invention relates to an aeration operation control system and an aeration operation control method for a sewage treatment apparatus, and is particularly suitable for application to a sewage treatment apparatus that purifies sewage using microorganisms in an aeration tank.

  2. Description of the Related Art Conventionally, a sewage treatment apparatus that purifies sewage using microorganisms in an aeration tank has been provided. In this type of sewage treatment apparatus, sewage is purified by allowing microorganisms to digest organic matter contained in the sewage after flowing into the aeration tank. Moreover, in order to activate microorganisms, it is comprised so that oxygen may be sent in an aeration tank by an aeration blower (blower) (for example, refer patent document 1, 2).

  Generally, the amount of sewage flowing into the aeration tank varies with time. For example, in ordinary households and business establishments, wastewater often flows into the aeration tank during daily activities, and wastewater flows into the aeration tank, but there is almost no inflow into the aeration tank at midnight. Moreover, the temperature of the wastewater discharged | emitted also changes and the activity degree of microorganisms also changes according to it. On the other hand, in many sewage treatment apparatuses, the aeration blower is operated continuously for 24 hours. For this reason, in some situations, excessive aeration may occur.

  If too much oxygen is sent to the aeration tank due to excessive aeration, the activity of microorganisms becomes too active, and the pH is excessively lowered by nitrification (action by microorganisms that produce nitrous acid and nitric acid from ammonia). As a result, the treated water discharged from the sewage treatment apparatus is acidic. In order to solve this problem, there is a method of intermittently operating the aeration blower with a timer, but there is a problem that fine control cannot be performed according to the situation of domestic wastewater.

  On the other hand, in the technique described in Patent Document 1, a temperature sensor that detects the temperature in the septic tank body is provided in the septic tank body, and a predetermined control temperature is set in advance. And when the temperature in the septic tank body with respect to the control temperature is high, the total amount of air sent to the reaction tank during aeration is reduced, and when the temperature in the septic tank body with respect to the control temperature is low, the total amount of air to be sent to the reaction tank during aeration is increased. Like to do.

  In the technique described in Patent Document 2, the water temperature of the aeration and stirring tank is measured, and the intermittent operation of the aeration and stirring tank is controlled according to an appropriate operation pattern corresponding to the water temperature. In the technique described in Patent Document 2, the dissolved oxygen (DO) in the aeration stirring tank is measured, and the air volume according to the dissolved oxygen volume is determined to control the air volume of the aeration blower.

JP 2000-589 A Japanese Patent Laid-Open No. 2002-224687

  However, in the operation control of the aeration blower based on the measurement result of the water temperature and the dissolved oxygen amount, there is a problem that the optimum aeration amount cannot always be controlled. The activity of microorganisms varies not only with the temperature of sewage and the amount of dissolved oxygen, but also with the amount of organic substances contained in the sewage and other complex factors. For this reason, it is difficult to control the amount of aeration so that the activity of the microorganism is optimized even if the water temperature and the amount of dissolved oxygen, which are only some parameters for grasping the activity status of the microorganism, are measured.

  The present invention has been made to solve such problems, and can control the operation of the aeration blower so that the activity of microorganisms in the aeration tank is optimized in accordance with the situation of domestic wastewater. The purpose is to do.

  In order to solve the above problems, in the present invention, the temperature of sewage in the aeration tank is detected by a temperature sensor, the pH of treated water purified by microorganisms is detected by a pH sensor, and the detected water temperature and Based on the pH, an operation ratio that is a ratio of a stop time and an operation time when the aeration blower is intermittently operated is set.

  The pH value of the treated water detected in the present invention configured as described above is the amount of sewage flowing into the aeration tank, the chemical nature, the situation of domestic wastewater such as the water temperature, and the organic matter contained in the sewage. This value reflects many factors, such as the degree of activity of microorganisms. According to the present invention, the pH of the treated water having such a property is detected, and the intermittent operation of the aeration blower is controlled according to the pH value and the water temperature. It is possible to control the operation of the aeration blower so that the activity of microorganisms in the inside becomes optimal.

It is a block diagram which shows the structural example of the aeration control system by 1st Embodiment. It is a figure which shows the example of the various information used in the aeration control system by 1st Embodiment. It is a flowchart which shows the operation example of the aeration control system by 1st Embodiment. It is a flowchart which shows the operation example of the detection process by 1st Embodiment. It is a flowchart which shows the operation example of the driving | running ratio calculation process by 1st Embodiment. It is a flowchart which shows the operation example of the control processing by 1st Embodiment. It is a block diagram which shows the structural example of the aeration control system by 2nd Embodiment. It is a flowchart which shows the operation example of the detection process by 2nd Embodiment. It is a flowchart which shows the operation example of the driving | running ratio calculation process by 2nd Embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of an aeration control system 100 according to the first embodiment. In FIG. 1, 120 is a sewage treatment apparatus that purifies sewage using microorganisms. An anaerobic filter bed tank (first chamber) 140, an anaerobic filter bed tank (second chamber) 150, an aeration tank 160, a precipitation tank. A tank 170 and a disinfection tank 180 are provided.

  The anaerobic filter bed (first room) 140 removes suspended matter in sewage, such as human waste from flush toilets and waste water from kitchens and baths (life drainage), and anaerobic filter bed tank (first room). (1 chamber) Anaerobic microorganisms (microorganisms that can survive in a place where oxygen is not present) attached to a filter medium (not shown) provided inside 140 decomposes organic matter in the sewage. The sewage treated in the anaerobic filter bed tank (first chamber) 140 flows into the anaerobic filter bed tank (second chamber) 150.

  In the anaerobic filter bed tank (second chamber) 150, the sewage flowing from the anaerobic filter bed tank (first chamber) 140 is the same as the processing performed in the anaerobic filter bed tank (first chamber) 140. The process is performed again. The sewage treated in the anaerobic filter bed tank (second chamber) 150 flows into the aeration tank 160.

  In the aeration tank 160, the sewage flowing from the anaerobic filter bed tank (second chamber) 150 is in the aeration tank 160 while the air is sufficiently fed from the aeration blower 220 that sends air into the aeration tank 160. Circulates, and a process (purification process) that decomposes organic matter by aerobic microorganisms (microorganisms that can survive only in the presence of oxygen) attached to a contact material (not shown) provided inside the aeration tank 160 Done. Further, in the aeration tank 160, a process (reverse cleaning process) in which aerobic microorganisms excessively attached to the contact material are separated using air sent from the aeration blower 220 is performed in a predetermined time zone (for example, 10 to 10 in the midnight time zone). 20 minutes).

  The purified water that has been purified in the aeration tank 160 flows into the settling tank 170. In the sedimentation tank 170, the microbial mass (sludge) of the purified treated water flowing from the aeration tank 160 sinks, and the supernatant water is sent to the disinfection tank 180 as treated water. In the disinfection tank 180, the treated water flowing from the settling tank 170 is sterilized and disinfected with a chlorine agent, and discharged as sanitary safe water.

  The aeration blower 220 is controlled by the blower operation control unit 460 because aerobic microorganisms require a large amount of oxygen to decompose organic matter in the sewage during the purification process performed in the aeration tank 160. A predetermined amount of air (for example, 45 [liter / min]) is intermittently sent into the tank 160. In addition, when the aeration blower 220 performs the reverse cleaning process on the aeration tank 160, the aeration blower 220 sends air of a predetermined air volume into the aeration tank 160 in a non-intermittent manner under the control of the blower operation control unit 460.

  A temperature sensor 240 is disposed in the aeration tank 160 in order to detect the temperature of sewage in the aeration tank 160. Reference numeral 260 denotes a temperature detection unit that detects the temperature of sewage in the aeration tank 160 with reference to the output value of the temperature sensor 240 every predetermined time (for example, 10 minutes). Then, the temperature detection unit 260 sequentially stores the detected water temperature in the temperature memory 280.

  A water temperature moving average calculation unit 300 calculates a moving average value (hereinafter referred to as a water temperature moving average value) over a predetermined time (for example, 24 hours) nearest to the water temperature stored in the temperature memory 280. Then, the water temperature moving average calculation unit 300 causes the temperature memory 280 to store water temperature information indicating the calculated water temperature moving average value. That is, the water temperature moving average calculating unit 300 calculates a water temperature moving average value and updates and stores it in the temperature memory 280 every time the water temperature is detected by the temperature detecting unit 260 every 10 minutes.

  Reference numeral 320 denotes a pH input receiving unit that receives an input of the pH of the treated water in the disinfection tank 180 through a user operation on an operation unit (not shown). In this embodiment, a maintenance / inspector of the sewage treatment apparatus 120 manually adjusts the pH of the treated water in the disinfection tank 180 using the portable pH sensor 480 at the timing of maintenance / inspection (for example, once / February). Detect with. Then, the maintenance inspection company inputs the detected pH through the operation unit. When pH input is received, pH input receiving unit 320 outputs pH information indicating the pH to operation ratio updating unit 400 of operation ratio setting unit 340.

  The operation ratio setting unit 340 stops the aeration blower 220 based on the water temperature moving average value indicated by the water temperature information output from the water temperature moving average calculating unit 300 and the pH accepted by the pH input accepting unit 320. Set the operation ratio, which is the ratio of time to operating time. In order to perform the operation ratio setting process, the operation ratio setting unit 340 includes a ratio pattern storage unit 360, an increase / decrease pattern storage unit 380, and an operation ratio update unit 400.

  The ratio pattern storage unit 360 stores a ratio pattern table that represents an operation ratio according to the temperature of sewage in the aeration tank 160. FIG. 2A is a diagram illustrating an example of a ratio pattern table according to the present embodiment. As shown in FIG. 2 (a), according to the temperature of sewage in the aeration tank 160 (for example, 5 to 45 ° C.), the operation ratio C that is the ratio of the stop time to the whole (for example, 30 minutes) is stored. The In the ratio pattern table shown in FIG. 2A, the initial value of the operation ratio C corresponding to each water temperature is 0 [%] (indicating continuous operation). The value of the operation ratio C is updated by the operation ratio update unit 400 at the timing when the input is accepted.

  The increase / decrease pattern storage unit 380 stores an increase / decrease pattern table that represents an increase / decrease value ΔC of the operation ratio according to the temperature of the sewage in the aeration tank 160 and the pH of the treated water in the disinfection tank 180. FIG. 2B is a diagram illustrating an example of an increase / decrease pattern table according to the present embodiment. As shown in FIG. 2 (b), even if the pH of the treated water is the same, the increase / decrease value of the operation ratio depends on whether the sewage water temperature in the aeration tank 160 belongs to the low water temperature region, the middle water temperature region, or the high water temperature region. ΔC varies (except for neutrality at pH = 7).

  For example, when the pH value is greater than 7 (when the treated water is alkaline), the increase / decrease value ΔC is a negative value. This is because it is necessary to increase the operating time of the aeration blower 220 by reducing the operation ratio in order to lower the pH by promoting the activation of the aerobic microorganism. Further, the absolute value of the increase / decrease value ΔC is increased as the pH value is increased. This is because the larger the pH value, the lower the pH by further promoting the activation of the aerobic microorganisms, and therefore it is necessary to increase the operating time of the aeration blower 220 by lowering the operation ratio.

  Further, the absolute value of the increase / decrease value ΔC in the low water temperature region and the middle water temperature region is made larger than that in the high water temperature region. This is to make it easier to activate the aerobic microorganisms in the aeration tank 160 by lowering the operation ratio and increasing the operation time of the aeration blower 220 as the temperature of the treated water in the aeration tank 160 is lower. .

  Further, when the pH value is less than 7 (when the treated water is acidic), the increase / decrease value ΔC is a positive value. This is because it is necessary to increase the operation ratio and increase the stop time of the aeration blower 220 in order to increase the pH by suppressing the activation of the aerobic microorganisms. In addition, the absolute value of the increase / decrease value ΔC is increased as the pH value is decreased. This is because, as the pH value is smaller, the pH is raised by further suppressing the activation of the aerobic microorganisms, so it is necessary to increase the operation ratio and increase the stop time of the aeration blower 220.

  Further, the absolute value of the increase / decrease value ΔC is increased in the order of the low water temperature region, the middle water temperature region, and the high water temperature region. This is because the higher the temperature of the treated water in the aeration tank 160, the higher the operation ratio and the longer the stop time of the aeration blower 220, thereby making it difficult to activate the aerobic microorganisms in the aeration tank 160. .

  When the pH value is 7 (when the treated water is neutral), the increase / decrease value is 0 in any of the “low water temperature region”, “medium water temperature region”, and “high water temperature region”. This is because the pH that is said to be most appropriate within the reference value of the discharged water (pH = 5.8 to 8.6) is 7, and control for deliberately changing the pH is unnecessary.

  The operation ratio update unit 400 stores the water temperature moving average value indicated by the water temperature information stored in the temperature memory 280 and the increase / decrease value ΔC corresponding to the pH indicated by the pH information output from the pH input reception unit 320. Obtained by referring to part 380. Then, the operation ratio update unit 400 refers to the ratio pattern table of the ratio pattern storage unit 360 and sets the value of the operation ratio C corresponding to the current (latest) water temperature stored in the temperature memory 280 as the operation. The value of the ratio C and the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 are updated to a value C + ΔC (hereinafter referred to as an addition value).

  Here, when the added value is larger than 90, the operation ratio update unit 400 updates the value of the operation ratio C to 90. This is because aerobic microorganisms in the aeration tank 160 cannot survive unless the operating time of the aeration blower 220 is secured to some extent. If the added value is smaller than 0, the operation ratio update unit 400 updates the value of the operation ratio C to 0.

  Further, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is a positive value, the operation ratio update unit 400 refers to the ratio pattern storage unit 360 and stores the current value stored in the temperature memory 280. The operation ratio C corresponding to each water temperature higher than the water temperature is updated to the same value as the operation ratio value (updated value) corresponding to the current water temperature. For example, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is +5, when the current water temperature is 20 [° C.], each water temperature (21 to 45 [° C.]) higher than the current water temperature is set. The corresponding operation ratio C value is updated to the operation ratio value corresponding to the current water temperature.

  By performing such an update process, when the increase / decrease value ΔC is a positive value (that is, when it is desired to increase the pH by suppressing the activation of the aerobic microorganism), the activation of the aerobic microorganism proceeds. It takes control to raise pH in a wide range of water temperature, and the time required to neutralize treated water can be shortened.

  Further, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is a negative value, the operation ratio update unit 400 refers to the ratio pattern storage unit 360 and stores the current value stored in the temperature memory 280. The value of the operation ratio C corresponding to each water temperature lower than the water temperature is updated to the value (updated value) of the operation ratio corresponding to the current water temperature. For example, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is −5, when the current water temperature is 35 [° C.], each water temperature lower than the current water temperature (5-34 [° C.]). The value of the operation ratio C corresponding to is updated to the value of the operation ratio corresponding to the current water temperature.

  By performing such an update process, when the increase / decrease value ΔC is a negative value (that is, when it is desired to lower the pH by promoting the activation of the aerobic microorganism), the activation of the aerobic microorganism is suppressed. It takes control to lower the pH in a wide range of water temperature, and the time required to neutralize the treated water can be shortened.

  Reference numeral 420 denotes a reverse cleaning time information storage unit that stores reverse cleaning time information indicating a time zone in which the reverse cleaning process should be performed on the aeration tank 160. Reference numeral 440 denotes a timer, which starts counting every predetermined time (for example, 30 minutes), and then sets a timeout time set by the blower operation control unit 460 based on the ratio pattern table of the ratio pattern storage unit 360 and the current water temperature. When it elapses, it times out and the count ends.

The blower operation control unit 460 stores the operation ratio C corresponding to the current water temperature stored in the temperature memory 280 in the ratio pattern storage unit 360 when the current time is not included in the time zone for performing the reverse cleaning process. The aeration blower 220 is intermittently operated according to the acquired operation ratio C. Specifically, the blower operation control unit 460 uses the timer 440 to stop the operation of the aeration blower 220 for each predetermined time by the stop time obtained by the following equation (1), and then from the predetermined time to the stop time. Control is performed to operate the aeration blower 220 for the operating time obtained by subtracting.
Stop time = predetermined time (30 minutes) * (operation ratio according to current water temperature / 100) (Equation 1)

  In addition, the blower operation control unit 460 performs control to operate the aeration blower 220 in order to perform the reverse cleaning process of the aeration tank 160 when the current time is included in the time zone in which the reverse cleaning process is to be performed.

  Next, the operation of the aeration control system 100 according to the first embodiment will be described. FIG. 3 is a flowchart showing an operation example of the aeration control system 100 according to the first embodiment. Each process shown in FIG. 3 is repeatedly performed until the aeration control system 100 stops after the aeration control system 100 is activated. As shown in FIG. 3, the operation of the aeration control system 100 is roughly divided into a detection process (step S100), an operation ratio calculation process (step S120), and a control process (step S140).

  First, details of the detection process (step S100) of FIG. 3 will be described. FIG. 4 is a flowchart illustrating an operation example of detection processing of the aeration control system 100 according to the first embodiment. First, the temperature detection unit 260 refers to an internal clock (not shown) and determines whether or not a predetermined time (for example, 10 minutes) has elapsed (step S200). If temperature detection unit 260 determines that the predetermined time has not elapsed (NO in step S200), aeration control system 100 ends the process in FIG.

  On the other hand, when temperature detection unit 260 determines that the predetermined time has elapsed (YES in step S200), temperature detection unit 260 refers to the output value of temperature sensor 240 to determine the temperature of sewage in aeration tank 160. It detects (step S210). Then, the temperature detection unit 260 stores the detected water temperature in the temperature memory 280.

  Next, the water temperature moving average calculation unit 300 calculates a moving average value over a predetermined time (for example, 24 hours) of the water temperature stored in the temperature memory 280 (step S220). Then, the water temperature moving average calculation unit 300 stores water temperature information indicating the value of the calculated water temperature moving average value in the temperature memory 280. Thereafter, the aeration control system 100 ends the process in FIG.

  Next, details of the operation ratio calculation process (step S120) of FIG. 3 will be described. FIG. 5 is a flowchart illustrating an operation example of the operation ratio calculation process in the aeration control system 100 according to the first embodiment. First, the pH input receiving unit 320 determines whether or not the input of the pH of the treated water in the disinfection tank 180 has been received through a user operation on the operation unit (not shown) (step S300). If the pH input receiving unit 320 determines that the pH input is not received (NO in step S300), the aeration control system 100 ends the process in FIG.

  On the other hand, when pH input receiving unit 320 determines that the input of pH has been received (YES in step S300), pH input receiving unit 320 provides pH information indicating the pH that has been input to the operation of operation ratio setting unit 340. The data is output to the ratio update unit 400. Next, the operation ratio update unit 400 calculates the water temperature moving average value indicated by the water temperature information stored in the temperature memory 280 and the increase / decrease value ΔC corresponding to the pH indicated by the pH information output from the pH input reception unit 320. The increase / decrease pattern storage unit 380 is referred to obtain (step S310).

  Next, the operation ratio update unit 400 acquires the value of the operation ratio C corresponding to the current water temperature stored in the temperature memory 280 by referring to the ratio pattern storage unit 360, and the value of the operation ratio C The increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is added (step S320). Next, the operation ratio update unit 400 determines whether or not the addition value (C + ΔC) obtained in step S320 is greater than 90 [%] (step S330).

  If the operation ratio update unit 400 determines that the added value is greater than 90 [%] (YES in step S330), the operation ratio update unit 400 sets the value of the operation ratio C corresponding to the current water temperature to 90. [%] Is updated (step S340). Thereafter, the process proceeds to step S380. On the other hand, when operation ratio update unit 400 determines that the addition value is not greater than 90 [%] (NO in step S330), operation ratio update unit 400 determines whether or not the addition value is less than 0 [%]. (Step S350).

  If the operation ratio update unit 400 determines that the added value is smaller than 0 [%] (YES in step S350), the operation ratio update unit 400 sets the value of the operation ratio C corresponding to the current water temperature to 0. [%] Is updated (step S360). Thereafter, the process proceeds to step S380. On the other hand, when operation ratio update unit 400 determines that the added value is not smaller than 0 [%] (NO in step S350), operation ratio update unit 400 sets the value of operation ratio C to that of operation ratio C. The value is updated to a value C + ΔC obtained by adding the value and the increase / decrease value ΔC. Thereafter, the process proceeds to step S380.

  In step S380, the operation ratio update unit 400 determines whether or not the increase / decrease value ΔC acquired in step S310 is a positive value. If operation ratio update unit 400 determines that increase / decrease value ΔC is a positive value (YES in step S380), operation ratio update unit 400 refers to temperature memory 280 to acquire the current water temperature. The value of the operation ratio C corresponding to each water temperature higher than the current water temperature in the ratio pattern table of the ratio pattern storage unit 360 is the operation ratio corresponding to the current water temperature updated in any of steps S340, S360, and S370. The value is updated to the same value (step S390). Thereafter, the aeration control system 100 ends the process in FIG.

  On the other hand, when operation ratio update unit 400 determines that increase / decrease value ΔC is not a positive value (NO in step S380), operation ratio update unit 400 determines that increase / decrease value ΔC acquired in step S310 is a negative value. It is determined whether or not there is (step S400). If the operation ratio update unit 400 determines that the increase / decrease value ΔC is not a negative value (that is, the increase / decrease value ΔC is 0) (NO in step S390), the aeration control system 100 performs the process in FIG. finish.

  On the other hand, when operation ratio update unit 400 determines that increase / decrease value ΔC is a negative value (YES in step S400), operation ratio update unit 400 refers to temperature memory 280 to acquire the current water temperature. In the ratio pattern table of the ratio pattern storage unit 360, the value of the operation ratio C corresponding to each water temperature lower than the current water temperature is set to the operation ratio corresponding to the current water temperature updated in any of steps S340, S360, and S370. The value is updated to the same value as (step S410). Thereafter, the aeration control system 100 ends the process in FIG.

  Next, details of the control process (step S140) of FIG. 3 will be described. FIG. 6 is a flowchart showing an operation example of control processing in the aeration control system 100 according to the first embodiment. First, the blower operation control unit 460 refers to the back cleaning time information stored in the back cleaning time information storage unit 420, and the current time indicated by an internal clock (not shown) is a time zone in which the back cleaning process is to be performed. (Step S500).

  If the blower operation control unit 460 determines that the current time is not included in the time zone for performing the reverse cleaning process (NO in step S500), the blower operation control unit 460 determines that the current time is a midnight time zone ( For example, it is determined whether it is included in 0 to 6 [hours]) (step S510). If the blower operation control unit 460 determines that the current time is not included in the midnight time zone (NO in step S510), the process transitions to step S550.

  On the other hand, when the blower operation control unit 460 determines that the current time is included in the midnight time zone (YES in step S510), the blower operation control unit 460 refers to the ratio pattern storage unit 360 and refers to the temperature memory 280. The operation ratio C corresponding to the current water temperature stored in is acquired. Then, the value of the operation ratio C is multiplied by a predetermined value (a value greater than 1, for example, 1.5) (step S520). Here, increasing the value of the operation ratio C by multiplying by a predetermined value (that is, lengthening the stop time of the aeration blower 220) is that there is almost no inflow of sewage into the aeration tank 160 in the midnight time zone. This is because the necessity for promoting the activation of the aerobic microorganisms in the tank 160 is small.

  Next, the blower operation control unit 460 determines whether or not the value of the operation ratio C after multiplication in Step S520 is greater than 90 [%] (Step S530). If the blower operation control unit 460 determines that the value of the operation ratio C is not greater than 90 [%] (NO in step S530), the process proceeds to step S550. That is, the blower operation control unit 460 employs the value of the operation ratio C multiplied by 1.5.

  On the other hand, if the blower operation control unit 460 determines that the value of the operation ratio C is greater than 90 [%] (YES in step S530), the blower operation control unit 460 sets the value of the operation ratio C to 90 [%]. (Step S540). Thereafter, the process proceeds to step S550.

  In step S550, the blower operation control unit 460 refers to the internal clock and determines whether or not a predetermined time (for example, 30 minutes) has passed since the previous count operation of the timer 440 was started. If the blower operation control unit 460 determines that the predetermined time has elapsed (YES in step S550), the blower operation control unit 460 sets the time-out time (= 30 * (C / 100) [minute]) to the timer 440. ) Is set to start the counting operation (step S560). Then, the blower operation control unit 460 stops the operation of the aeration blower 220 (step S570). Thereafter, the aeration control system 100 ends the process in FIG.

  On the other hand, if the blower operation control unit 460 determines that the predetermined time has not elapsed (NO in step S550), the blower operation control unit 460 confirms the operation state of the timer 440 and whether the timer 440 has timed out. It is determined whether or not (step S610). If the blower operation control unit 460 determines that the timer 440 has not timed out (NO in step S610), the aeration control system 100 ends the process in FIG.

  On the other hand, when the blower operation control unit 460 determines that the timer 440 has timed out (YES in step S610), since the stop time of the aeration blower 220 has ended, the blower operation control unit 460 starts the operation of the aeration blower 220. (Step S620). Thereafter, the aeration control system 100 ends the process in FIG.

  When the blower operation control unit 460 determines that the current time is included in the time zone for performing the reverse cleaning process (YES in step S500), the blower operation control unit 460 confirms the operation state of the timer 440. Then, it is determined whether or not the timer 440 is counting (step S580). If the timer 440 is not counting (that is, the aeration blower 220 is operating) and the blower operation control unit 460 determines (NO in step S580), the aeration control system 100 performs the processing in FIG. finish. That is, the operating state of the aeration blower 220 is maintained as it is.

  On the other hand, when the blower operation control unit 460 determines that the timer 440 is counting (that is, the aeration blower 220 is stopped) (YES in step S580), the blower operation control unit 460 determines the timer 440. Is stopped (step S590). Then, the blower operation control unit 460 starts the operation of the aeration blower 220 (step S600). Thereafter, the aeration control system 100 ends the process in FIG.

  As described above in detail, in the first embodiment, the temperature sensor 240 detects the water temperature of sewage in the aeration tank 160 and the pH sensor 480 detects the pH of treated water that has been purified by microorganisms. Based on the detected water temperature and pH, the operation ratio C, which is the ratio between the stop time and the operation time when the aeration blower 220 is operated intermittently, is set based on the detected water temperature and pH.

  According to the first embodiment configured as above, in addition to the situation of domestic wastewater such as the amount of sewage flowing into the aeration tank 160, chemical properties, and water temperature, the degree of activity of microorganisms that decompose organic substances contained in the sewage Since the intermittent operation of the aeration blower 220 is controlled according to the pH value and water temperature reflecting many factors, the activity of microorganisms in the aeration tank 160 is optimized according to the situation of domestic wastewater. The operation of the aeration blower 220 can be controlled.

  In the first embodiment, an increase / decrease value ΔC corresponding to the water temperature detected by the temperature sensor 240 and the pH detected by the pH sensor 480 is acquired with reference to the increase / decrease pattern table, and the acquired increase / decrease value ΔC is obtained. Based on this, the value of the operation ratio C in the ratio pattern table is updated. In this way, since the increase / decrease value ΔC used to update the value of the operation ratio C can be easily obtained by referring to the increase / decrease pattern table, the value of the operation ratio C is detected after the water temperature and pH are detected. Can be updated in a short time.

  In the first embodiment, not only the value of the operation ratio C corresponding to the current water temperature but also the increase / decrease value ΔC is equal to or higher than the current water temperature or lower than the current water temperature depending on whether the increase / decrease value ΔC is a positive value or a negative value. All values of the operation ratio C corresponding to the water temperature are updated. In this way, when the increase / decrease value ΔC is a positive value (that is, when it is desired to raise the pH by suppressing the activation of the aerobic microorganisms), the water temperature of a wide range that the activation of the aerobic microorganisms proceeds. Control to raise pH in the range is applied, and the time required to neutralize the treated water can be shortened. In addition, when the increase / decrease value ΔC is a negative value (that is, when it is desired to lower the pH by promoting the activation of the aerobic microorganism), the pH is adjusted within a wide water temperature range in which the activation of the aerobic microorganism is suppressed. Lowering control is required, and the time required to neutralize the treated water can be shortened.

  In the first embodiment, the example in which the moving average value of the water temperature detected over 24 hours and the increase / decrease value ΔC corresponding to the current pH are acquired from the increase / decrease pattern table is described, but the present invention is not limited to this. . For example, the increase / decrease value ΔC corresponding to the current water temperature and the current pH may be acquired from the increase / decrease pattern. In this case, the temperature sensor may be the one brought by the user (maintenance / inspection contractor) at the time of inspection.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram illustrating a configuration example of the aeration control system 100 according to the second embodiment. As shown in FIG. 7, the aeration control system 100 does not include the pH input receiving unit 320 and the pH sensor 480 of FIG. The aeration control system 100 further includes a pH sensor 500, a pH detection unit 520, a pH memory 540, and a pH moving average calculation unit 560. Further, the aeration control system 100 includes an operation ratio update unit 400 ′ instead of the operation ratio update unit 400 of FIG. In FIG. 7, those given the same reference numerals as those shown in FIG. 1 have the same functions, and therefore redundant description is omitted here.

  The pH sensor 500 is disposed in the disinfection tank 180 in order to detect the pH of the treated water that has been purified by microorganisms. Similarly to the temperature detection unit 260, the pH detection unit 520 detects the pH of the treated water in the disinfection tank 180 with reference to the output value of the pH sensor 500 every predetermined time (for example, 10 minutes). Then, the pH detection unit 520 sequentially stores the detected pH in the pH memory 540.

  The pH moving average calculation unit 560 calculates a moving average value (hereinafter referred to as a pH moving average value) over a predetermined time (for example, 24 hours) nearest to the pH stored in the pH memory 540. Then, the pH moving average calculating unit 560 stores pH information indicating the calculated pH moving average value in the pH memory 540. That is, the pH moving average calculating unit 560 calculates a pH moving average value and updates and stores it in the pH memory 540 every time pH is detected by the pH detecting unit 520 every 10 minutes.

  The operation ratio update unit 400 ′ has a water temperature moving average value indicated by the water temperature information stored in the temperature memory 280 and a pH moving average value indicated by the pH information stored in the pH memory 540 every predetermined time (24 hours). The increase / decrease value ΔC corresponding to the reference is acquired with reference to the increase / decrease pattern storage unit 380. Then, the operation ratio update unit 400 ′ updates the ratio pattern table of the ratio pattern storage unit 360 in the same manner as the operation ratio update unit 400.

  Next, the operation of the aeration control system 100 according to the second embodiment will be described. Also in the second embodiment, the operation of the aeration control system 100 is roughly divided into a detection process (step S100), an operation ratio calculation process (step S120), and a control process (step S140) as shown in FIG. .

  FIG. 8 is a flowchart showing an operation example of the detection process (step S100) of the aeration control system 100 according to the second embodiment. First, the temperature detector 260 refers to an internal clock (not shown) and determines whether or not a predetermined time (for example, 10 minutes) has elapsed (step S700). If temperature detection unit 260 determines that the predetermined time has not elapsed (NO in step S700), aeration control system 100 ends the process in FIG.

  On the other hand, when temperature detection unit 260 determines that the predetermined time has elapsed (YES in step S700), temperature detection unit 260 refers to the output value of temperature sensor 240 and determines the temperature of sewage in aeration tank 160. Detection is performed (step S710). Then, the temperature detection unit 260 stores the detected water temperature in the temperature memory 280.

  Next, the water temperature moving average calculation unit 300 calculates a moving average value over a predetermined time (for example, 24 hours) of the water temperature stored in the temperature memory 280 (step S720). Then, the water temperature moving average calculation unit 300 stores water temperature information indicating the value of the calculated water temperature moving average value in the temperature memory 280.

  Next, the pH detection unit 520 detects the pH of the treated water in the disinfection tank 180 with reference to the output value of the pH sensor 500 (step S730). Then, the pH detection unit 520 stores the detected pH in the pH memory 540.

  Next, the pH moving average calculator 560 calculates a moving average value over a predetermined time (for example, 24 hours) of the pH stored in the pH memory 540 (step S740). Then, the pH moving average calculating unit 560 stores pH information indicating the calculated pH moving average value in the pH memory 540. Thereafter, the aeration control system 100 ends the process in FIG.

  Next, the operation ratio calculation process (step S120) in FIG. 3 will be described. FIG. 9 is a flowchart illustrating an operation example of the operation ratio calculation process in the aeration control system 100 according to the second embodiment. First, the operation ratio updating unit 400 ′ refers to the value of the internal clock and determines whether or not a predetermined time (for example, 24 hours) has elapsed (step S800). If the operation ratio update unit 400 ′ determines that the predetermined time has not elapsed (NO in step S800), the aeration control system 100 ends the process in FIG.

  On the other hand, when operation ratio update unit 400 ′ determines that the predetermined time has elapsed (YES in step S800), operation ratio update unit 400 ′ uses the water temperature moving average indicated by the water temperature information stored in temperature memory 280. The increase / decrease value ΔC corresponding to the value and the pH moving average value indicated by the pH information stored in the pH memory 540 is acquired with reference to the increase / decrease pattern storage unit 380 (step S810). The subsequent processing is the same as steps S310 to S410 in FIG. In addition, since the control processing (step S140) of the aeration control system 100 according to the second embodiment is also exactly the same as that of the first embodiment, illustration and description thereof are omitted.

  As described in detail above, in the second embodiment, the temperature sensor 240 detects the temperature of sewage in the aeration tank 160, and the pH sensor 500 detects the pH of treated water that has been purified by microorganisms. The operation ratio is set every predetermined time (24 hours) based on the detected water temperature and pH.

  According to the second embodiment configured as described above, since the intermittent operation of the aeration blower 220 is controlled in accordance with the automatically detected pH and water temperature, the maintenance inspection company detects and inputs the pH. Compared with the embodiment, it is possible to reduce the work load of the maintenance inspection company. In addition, since the operation ratio C is updated every predetermined time (24 hours), it is shorter than the first embodiment in which the operation ratio C is updated at the timing of maintenance inspection (for example, once / February). Thus, the operation of the aeration blower 220 can be controlled so that the activity of microorganisms in the aeration tank 160 is optimized in response to changes in pH and water temperature in a short period of time.

  In the second embodiment, the example in which the increase / decrease value ΔC corresponding to the water temperature moving average value and the pH moving average value is acquired from the increase / decrease pattern table is described, but the present invention is not limited to this. For example, you may make it acquire the increase / decrease value (DELTA) C according to the present water temperature and pH moving average value from an increase / decrease pattern table.

  In the first and second embodiments, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is a positive value, the operation corresponding to each water temperature higher than the current water temperature in the ratio pattern table. Although the example which updates all the values of the ratio C according to the update value of the operation ratio C corresponding to the present water temperature was demonstrated, this invention is not limited to this. For example, the value of the operation ratio C corresponding to each water temperature higher than the current water temperature may be updated to a value obtained by adding the increase / decrease value ΔC to the value of each operation ratio C.

  In the first and second embodiments, when the increase / decrease value ΔC acquired with reference to the increase / decrease pattern storage unit 380 is a negative value, the operation corresponding to each water temperature lower than the current water temperature in the ratio pattern table. Although the example which updates the value of the ratio C according to the update value of the operation ratio C corresponding to the present water temperature was demonstrated, this invention is not limited to this. For example, the value of the operation ratio C corresponding to each water temperature lower than the current water temperature may be updated to a value obtained by adding the increase / decrease value ΔC to the value of each operation ratio C.

  Moreover, although the said 1st and 2nd embodiment demonstrated the example which makes the driving | running ratio C the ratio of the stop time with respect to the whole (for example, 30 minutes), this invention is not limited to this. For example, the operation ratio C may be the ratio of the operation time to the whole.

  Moreover, although the said 1st and 2nd embodiment demonstrated the example which represents the driving | running ratio C by the ratio [%] of the stop time with respect to the whole, this invention is not limited to this. For example, the operation ratio C may be directly expressed as a stop time [minute].

  Further, the interval value (10 minutes) for detecting the water temperature and pH shown in the first and second embodiments, and the time value (24) that defines the range of detection data used when calculating the moving average value. Time) and the value of the time (30 minutes) during which the aeration blower 220 is intermittently operated are merely examples, and may be appropriately variably set according to the operation method of the aeration control system 100.

  In the first and second embodiments, the anaerobic filter bed tank is composed of two chambers (anaerobic filter bed tank (first chamber) 140 and anaerobic filter bed tank (second chamber) 150). However, the present invention is not limited to this. For example, you may make it comprise an anaerobic filter bed tank only by one room (anaerobic filter bed tank (1st chamber) 140).

  In addition, each of the first and second embodiments described above is merely an example of a specific example for carrying out the present invention, and the technical scope of the present invention should not be interpreted in a limited manner. It will not be. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

DESCRIPTION OF SYMBOLS 100 Aeration control system 120 Sewage treatment apparatus 160 Aeration tank 220 Aeration blower 240 Temperature sensor 340 Operation ratio setting part 360 Ratio pattern memory | storage part 380 Increase / decrease pattern memory | storage part 400,400 'Operation ratio update part 460 Blower operation control part 480,500 pH sensor

Claims (4)

An aeration operation control system that controls the operation of an aeration blower that sends air into the aeration tank in a sewage treatment apparatus that purifies sewage using microorganisms in the aeration tank,
Based on the water temperature detected by the temperature sensor that detects the temperature of the sewage in the aeration tank, and the pH detected by the pH sensor that detects the pH of the treated water purified by the microorganisms, the aeration blower An operation ratio setting unit for setting an operation ratio that is a ratio of the stop time and the operation time;
An aeration operation control system for a sewage treatment apparatus, comprising: a blower operation control unit that intermittently operates the aeration blower according to the operation ratio set by the operation ratio setting unit. The operation ratio setting unit is a ratio pattern storage unit that stores a ratio pattern representing the operation ratio according to the temperature of sewage in the aeration tank,
An increase / decrease pattern storage unit for storing an increase / decrease pattern representing an increase / decrease value of the operation ratio according to the temperature of sewage in the aeration tank and the pH of the treated water;
An increase / decrease value corresponding to the water temperature detected by the temperature sensor and the pH detected by the pH sensor is acquired with reference to the increase / decrease pattern, and the value of the operation ratio in the ratio pattern based on the acquired increase / decrease value. And an operation ratio update unit for updating
The blower operation control unit acquires the operation ratio according to the water temperature detected by the temperature sensor with reference to the ratio pattern, and intermittently operates the aeration blower according to the acquired operation ratio. The aeration operation control system of the sewage treatment apparatus according to claim 1. When the increase / decrease value acquired with reference to the increase / decrease pattern is a positive value, the operation ratio update unit sets all the values of the operation ratio corresponding to the water temperature equal to or higher than the current water temperature detected by the temperature sensor. When the increase / decrease value updated based on the increase / decrease value and obtained by referring to the increase / decrease pattern is a negative value, all the operation ratio values corresponding to the water temperature below the current water temperature detected by the temperature sensor are all The aeration operation control system for a sewage treatment apparatus according to claim 2, wherein the aeration operation control system is updated based on the increase / decrease value. An aeration operation control method for controlling the operation of an aeration blower that sends air into the aeration tank in a sewage treatment apparatus that purifies sewage using microorganisms in the aeration tank,
A first step of determining whether or not a trigger for updating an operation ratio that is a ratio of a stop time and an operation time of the aeration blower has occurred;
When it is determined that the trigger has occurred, the operation ratio setting unit detects the water temperature detected by the temperature sensor that detects the water temperature of the sewage in the aeration tank, and the pH of the treated water that has been purified by the microorganisms. A second step of setting an operation ratio that is a ratio of the stop time and the operation time of the aeration blower based on the pH detected by the pH sensor;
And a third step of controlling the blower operation control unit to intermittently operate the aeration blower according to the operation ratio set in the second step. .

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