JP3802185B2 - Sewage treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewage treatment apparatus, and more particularly, to a sewage treatment apparatus such as a combined treatment septic tank incorporating a dephosphorization treatment apparatus for removing phosphoric acid from sewage mixed with manure wastewater and domestic wastewater.
[0002]
[Prior art]
As this kind of dephosphorization processing apparatus, those disclosed in Japanese Patent Application Laid-Open No. 7-108296 (C02F 3/30) and Japanese Patent Application Laid-Open No. 3-89998 (C02F 3/12, 1/58, 11/00) It has been known.
[0003]
The former is an anaerobic filter bed or sedimentation separation tank, an aeration tank, a sedimentation tank, and a disinfection tank arranged in this order. Is a sewage treatment apparatus which is returned to the anaerobic filter bed tank or the precipitation separation tank.
[0004]
The latter includes a liquid receiving tank such as a flow rate adjusting tank or a sedimentation separation tank, a biological treatment tank, and a sludge concentration tank, and an insoluble phosphate-forming metal and at least one place on the path from the biological treatment tank to the liquid receiving tank. Place a noble metal in a conductive state, or place a pair of insoluble phosphate-forming metals and apply a voltage between them to electrochemically dissolve insoluble phosphate-forming metal ions in the liquid. It is an apparatus that is supplied to remove phosphorus.
[0005]
[Problems to be solved by the invention]
In the former case, if iron is eluted, iron will be consumed, so it is necessary to replenish iron. However, since the sewage treatment equipment (septic tank) is mostly buried outdoors in the ground, go out outdoors to check for the presence of iron and pull the iron electrode from the septic tank to the ground or look inside the septic tank. It has to be troublesome. However, if the inspection is not carried out, the iron as an electrode in the iron dissolving apparatus is lost and phosphoric acid is not removed, so that there is a problem that the septic tank does not fulfill its original purpose of removing phosphorus.
[0006]
In the latter case, since metal ions are dissolved in the liquid from the insoluble phosphate-forming metal on the anode side, it is necessary to replenish the metal, so that there is a problem similar to the former case.
[0007]
However, in both the former and the latter, the iron electrode or insoluble phosphate-forming metal should be drawn from the septic tank to the ground, or the inspection time of the iron electrode or insoluble phosphate-forming metal should be judged without looking into the septic tank. There is no means or member that can be used.
[0008]
The present invention has been made in view of such circumstances, and it is possible to perform stable dissolution of an electrode, and to easily remove the phosphoric acid from which the timing of inspection of the electrode for electrode replacement or maintenance can be easily understood. An object of the present invention is to provide a sewage treatment apparatus.
[0009]
[Means for Solving the Problems]
According to one aspect of the present invention, at least a pair of electrodes to elute iron ions or aluminum ions for removing phosphoric acid in the treated water, from the electrodes of the electrolyzed treated water phosphate ions An ion concentration detection unit for detecting the concentration and a notification unit for notifying the inspection time of the electrode, and when the concentration of phosphate ions detected by the ion concentration detection unit exceeds a predetermined value, the notification unit A sewage treatment apparatus is provided that performs the notification.
[0010]
The electrode elutes iron ions or aluminum ions by electrolysis. These ions react with phosphoric acid in the waste water (orthophosphoric acid), become insoluble phosphorus compounds _{(Fe (OH) X (PO} 4) y or _{(Al (OH) X (PO} 4) y) A current for electrolysis is applied between the electrodes, and a control unit provided as desired controls the amount of ions eluted by controlling the current applied between the electrodes.
[0011]
The pair of electrodes, for example, are both constructed from one of iron and aluminum, or one from one of iron and aluminum and the other from an insoluble metal. In the former case, it is possible to prevent the electrode from being passivated by preventing the ion elution from the electrode by reversing the polarity of the electrode as desired. In the latter case, an electrode composed of one of iron and aluminum is used as an anode, and an electrode composed of an insoluble metal is used as a cathode. Here, as an electrode comprised from the insoluble metal, there exist electrodes, such as silver and platinum, for example.
[0012]
The sewage treatment apparatus is further provided with a characteristic ion concentration detection unit and a notification unit.
[0013]
This ion concentration detection unit detects the concentration of phosphate ion PO ₄ ³⁻ in the treated water that has flowed out as the electrolysis progresses. The ion concentration detection unit includes, for example, a detection tank for storing treated water in which the ions are electrolyzed, and an ion concentration sensor disposed in the detection tank.
[0014]
The detection tank is, for example, for temporarily storing treated water flowing in through an outflow pipe through which treated water flows.
[0015]
As a sensor for detecting the phosphate ion concentration in the treated water, for example, there is a known sensor having an ion sensitive film holding an ion sensitive substance made of a copper complex having a chain diamine as a ligand. Preferably used.
[0016]
The notification unit notifies the electrode replacement time. The notification unit includes, for example, at least one of a visual notification unit and an auditory notification unit. That is, the notification unit includes both or one of a visual notification unit such as an LED lamp and an auditory notification unit such as a buzzer.
[0017]
When the concentration of phosphate ions detected by the ion concentration detection unit exceeds a predetermined value, the control unit instructs the notification unit to perform the notification. That is, when the ion concentration detector detects that the phosphate ion concentration exceeds a predetermined value and the detection result is input to a control unit provided as desired, the control unit notifies the notification unit of the electrode inspection time. An instruction for informing the user is output to notify the user. Elution of ions can be continued by a manager (a contractor, a maintenance manager, etc.) who has been contacted by a user of the sewage treatment apparatus inspecting the electrode and replacing or maintaining it.
[0018]
According to another aspect of the present invention, at least a pair of electrodes for eluting iron ions or aluminum ions for removing phosphoric acid in the treated water, and the concentration of phosphate ions in the treated water electrolyzed from these electrodes An ion concentration detection unit for detecting the electrode, a notification unit for notifying the inspection time of the electrode, and a voltage detection unit for detecting the voltage between the electrodes at the time of electrolysis , the amount of the ions eluted from the electrode In order to make it constant, the interelectrode voltage is increased according to the amount of the ions, the concentration of phosphate ions detected by the ion concentration detector exceeds a predetermined value, and the interelectrode voltage detected by the voltage detector is A sewage treatment apparatus is provided in which a notification unit performs the notification when the reference value is equal to or greater than a reference value.
[0019]
This sewage treatment apparatus is further provided with a characteristic voltage detection unit in addition to the ion concentration detection unit and the notification unit. This voltage detection part detects the voltage between electrodes at the time of electrolysis. That is, as the electrolysis progresses, ions continue to elute from the electrode, and as a result, the surface area of the electrode gradually decreases. At this time, in order to make the eluted ion amount per unit time constant, it is necessary to increase the voltage between the electrodes. When the surface area of the electrode decreases to a certain value, the voltage between the electrodes rises to a considerably high value, which may cause an electric shock, and there is a possibility that a necessary amount of ion elution will not occur. Therefore, by providing a voltage detection unit, when the voltage between the electrodes becomes equal to or higher than the reference value, the inspection time of the electrodes is notified. For example, a voltage sensor connected between both electrodes is used as the voltage detection unit.
[0020]
When the concentration of phosphate ions detected by the ion concentration detection unit exceeds a predetermined value and the voltage between the electrodes detected by the voltage detection unit is equal to or higher than a reference value, the notification unit performs the notification. That is, the ion concentration detection unit detects that the concentration of phosphate ions has exceeded a predetermined value, and based on the detection result, a control unit provided as desired increases the amount of eluted ions per unit time to a predetermined value. When the voltage detection unit detects that the inter-electrode voltage is equal to or higher than the reference value when the inter-electrode voltage is increased, the control unit outputs an instruction to notify the notification unit of the electrode inspection time. By this notification, an administrator who has been contacted by the user of the sewage treatment apparatus inspects the electrode and replaces or maintains it, so that ion elution can be continued.
[0021]
An example of control by the control unit is that when the concentration of phosphate ions detected by the ion concentration detection unit exceeds a predetermined value and the voltage between the electrodes detected by the voltage detection unit is 25 V or more, the notification unit checks the electrode. The control for notifying the time is performed. As described above, when the surface area of the electrode is consumed to a certain value as the constant current electrolysis progresses, the voltage between the electrodes rises to a considerably high value, and there is a risk of electric shock, and the required amount of ions is eluted. May not occur. In view of this, when the phosphate ion concentration exceeds a predetermined value and the inter-electrode voltage becomes 25 V or more, it is considered that these fears occur, and the inspection time of the electrode is notified.
[0022]
According to still another aspect of the present invention, there is provided a sewage treatment apparatus incorporating the various dephosphorization treatment apparatuses. For example, a dephosphorization processing device is arranged in the upper part of the biofilm filtration tank (bacterial tank) of the merged processing septic tank or the next processing water tank (precipitation tank) adjacent to this, and the contaminant removal tank (first) There is provided a combined treatment septic tank configured to remove phosphoric acid from the treated water returned to the anaerobic filter bed tank).
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, two embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to these.
[0024]
Embodiment 1
As shown in FIG. 1, dephosphorization processing apparatuses D ₁ according to one embodiment of the present invention is used incorporated into a small combined treatment septic tank 1 as sewage treatment apparatus with a flow rate adjusting function.
[0025]
The inside of the septic tank 1 is arranged in the order of the sewage purification process from the side of the inflow pipe 2 into which sewage mixed with human wastewater and domestic wastewater flows to the side of the discharge pipe 3 that discharges sewage-treated water to the outside. Accordingly, a tank structure is formed in which a plurality of tanks are partitioned.
[0026]
Reference numeral 4 denotes a contaminant removal tank that is partitioned and formed in the forefront portion on the inflow pipe 2 side. In this foreign matter removal tank 4, the foreign matter which is mixed in human waste water and domestic waste water and cannot be purified is separated and removed.
[0027]
An inflow guide 5 is defined on the inflow pipe 2 side of the contaminant removal tank 4. Between the inflow guide 5 and the inflow pipe 2, a rectangular or cylindrical downflow passage 6 that guides the inflow water toward the lower side of the contaminant removal tank 4 is formed.
[0028]
The contaminant removal tank 4 is provided with an anaerobic filter bed 7 which is a filter bed for anaerobic microorganisms, and anaerobic treatment is performed by causing the anaerobic filter bed 7 to inhabit the microorganisms. The anaerobic filter bed 7 suppresses the sediment from being rolled up by the water flow when inflow water or backwash wastewater flows in temporarily, and flowing out to the next tank as a floating substance, thereby reducing the load on the next tank. Can be lowered.
[0029]
Reference numeral 8 denotes a next anaerobic filter bed tank formed adjacent to the contaminant removal tank 4. In the anaerobic filter bed tank 8, anaerobic treatment is performed by causing the anaerobic filter bed 9 to inhabit anaerobic microorganisms.
[0030]
Reference numeral 10 denotes a next biofilm filtration tank that is formed adjacent to the anaerobic filter bed tank 8. The biofilm filtration tank 10 is provided with an aerobic filter bed 11 which is a filter bed of aerobic microorganisms, and aerobic microorganisms are inhaled in the aerobic filter bed 11 to perform aerobic treatment. ing.
[0031]
Reference numeral 12 denotes a next treated water tank formed adjacent to the biofilm filtration tank 11. In the treated water tank 12, the treated water that has been aerobically treated in the biofilm filtration tank 11, filtered, and transferred is stored stationary.
[0032]
Reference numeral 13 denotes a disinfection tank that is partitioned on the upper portion of the treated water tank 12. The sterilization tank 13 is usually configured to sterilize the supernatant water that has been treated in the treatment water tank 12 and discharge the supernatant water from the discharge pipe 3 to the outside.
[0033]
The contaminant removal tank 4 and the anaerobic filter bed tank 8 are partitioned by a vertical partition 14. An advection port 15 penetrating the partition wall 14 is formed in the upper part of the partition wall 14. The advection port 15 is fitted with a rectangular or cylindrical advection tube 16. The lower end of the advection pipe 16 is located below the anaerobic filter bed 7 of the foreign matter treatment tank 4 and also serves as a cleaning port.
[0034]
The anaerobic filter bed tank 8 and the next biofilm filtration tank 10 are partitioned by an intermediate partition wall 17. An upflow passage 18 is fixedly provided on the anaerobic filter bed 8 side of the intermediate partition wall 17. The sewage that has flowed from the contaminant removal tank 4 through the advection pipe 16 to the anaerobic filter bed tank 8 passes through the anaerobic filter bed 9 in a downward flow, and then rises through the upflow passage 18.
[0035]
A water intake port of a metering pump (not shown) is provided in the upper part of the upflow passage 18. The metering pump transfers a certain amount of sewage from the anaerobic filter bed tank 8 to the biofilm filtration tank 10. That is, the sewage is taken into the metering pump from the water intake and is sent to the next biofilm filtration tank 10 by a certain amount.
[0036]
A certain amount of suspended matter (SS) is trapped in the anaerobic filter bed 9 in the anaerobic filter bed tank 8. The captured SS is gradually anaerobically decomposed to become soluble, or stored as sludge at the bottom of the anaerobic filter bed tank 8. In the anaerobic filter bed 9, organic nitrogen is anaerobically decomposed into ammonia nitrogen.
[0037]
In the vicinity of the bottom of the biofilm filtration tank 10, an air diffuser 22 of the air diffuser 21 is arranged in a horizontal state. The aeration device 21 performs an oxygen supply function for aerobic microorganisms living in the aerobic filter bed 11 of the biofilm filtration tank 10 by blowing air from the aeration tube 22.
[0038]
A filter medium is disposed in the aerobic filter bed 11 in the biofilm filtration tank 10, and microorganisms attached to the filter medium decompose the BOD component or the like, or convert it to SS and trap it on the filter medium. The biofilm filtration tank 10 also has a physical filtration action, and again captures SS. Moreover, in the biofilm filtration tank 10, ammonia nitrogen is changed to nitrate nitrogen by the action of nitrate bacteria and nitrite bacteria that change nitrogen to nitric acid.
[0039]
A partition wall 23 is provided between the biofilm filtration tank 10 and the next treated water tank 12. A communication portion 24 is provided below the partition wall 23. And the biofilm filtration tank 10 and the treated water tank 12 are connected by this communication part 24.
[0040]
In the treated water tank 12, the treated water that has flowed from the biofilm filtration tank 10 through the communication portion 24 is separated into a precipitate and a supernatant water. The bottom of the treated water tank 12 is inclined to return the sediment deposited there to the biofilm filtration tank 10 through the communication part 24.
[0041]
The bottom part of the biofilm filtration tank 10 and the upper part of the contaminant removal tank 4 are communicated with each other by an L-shaped first return pipe 25 composed of a vertical part 25a and a horizontal part 25b. A first air supply pipe 31 a is arranged inside the vertical portion 25 a of the first return pipe 25. The first air supply pipe 31 a is connected to the blower 30 outside the tank constituting the air lift pump 29 via the air lift supply pipe 31. Then, the air supplied from the blower 30 is blown out from the first air supply pipe 31 a so that the sludge accumulated on the bottom of the biofilm filtration tank 10 is sucked into the first return pipe 25 and returned to the contaminant removal tank 4. It has become.
[0042]
On the other hand, the supernatant water of the treated water in the treated water tank 12 is pumped up from the lift pipe 32 by the air blown out from the second air supply pipe 31 b disposed inside the lift pipe 32 and communicating with the air supply pipe 31. The first supply pipe 31a and the second supply pipe 31b can be switched to either one by a switching valve.
[0043]
A circulation path 26 is provided from the upper part of the treated water tank 12 to the upper part of the contaminant removal tank 4 for constantly returning the supernatant water of the treated water. The circulation path 26 is provided with a diversion meter 27, a dephosphorization device D ₁ , and an inlet 28 to the contaminant removal tank in the order of water flow from the treated water tank 12. Then, the supernatant water pumped up from the lift tube 32, diversion metering device 27, after being subjected to a dephosphorylation treatment device D _1, through the circulation path 26 back to the top of the descending flow path 6 of contaminant removal tank 4 It is.
[0044]
The diversion meter 27 is installed in the upper part of the treated water tank 12, and is integrally formed in a rectangular box-shaped bottomed structure from the front and rear plate portions, the left and right side plate portions, and the bottom plate portion. The inside of the box is partitioned into an inflow chamber, a water diversion chamber, and an intermediate chamber between the two.
[0045]
In the inflow chamber, an inflow pipe through which the supernatant water pumped from the lift pipe 32 of the air lift pump 29 flows is installed. The inflow chamber and the intermediate chamber are partitioned by a partition wall formed so that the lower side can be communicated, and the treated water that has flowed into the inflow chamber is diverted and transferred to the intermediate chamber.
[0046]
The diversion chamber is divided into two chambers, a first diversion chamber and a second diversion chamber. The partition wall between the first water diversion chamber and the intermediate chamber has a lower end fixed to the bottom plate and an upper end opened in a V shape. The partition wall between the second water diversion chamber and the intermediate chamber has a lower end fixed to the bottom plate and an upper end opened in a concave shape. And the overflow dam plate which can adjust the open dimension is attached to the partition opened to this concave shape.
[0047]
An outflow pipe for allowing treated water to flow out to the circulation path 26 is connected to the first diversion chamber, and an outflow pipe for letting out treated water to the biofilm filtration tank 10 is connected to the second diversion chamber. Has been. Therefore, the treated water that has flowed into the inflow chamber passes through the intermediate chamber and is divided into a circulation path and a biofilm filtration tank in the two water diversion chambers by adjusting the height of the overflow weir plate.
[0048]
As shown in FIG. 2 in an enlarged manner, the dephosphorization processing device D ₁ includes an elution tank 39, rectangular plate-like iron electrodes 40 and 41 disposed in the elution tank 39, and the electrodes 40 and 41. A DC power supply 42 for applying a current and a control unit 43 are provided. The electrodes 40 and 41 use iron for both the anode and the cathode.
[0049]
In the elution tank 39, treated water as sewage to be treated, which has flowed out from the outflow pipe 37, is stored. The iron electrodes 40 and 41 elute iron ions that react with phosphoric acid by electrolysis. The controller 43 controls the amount of iron ions eluted in the elution tank 39 by controlling the current applied between the electrodes 40 and 41.
[0050]
The elution tank 39 is provided in the upper part of the biofilm filtration tank 10, and is integrally formed in a rectangular box-shaped bottomed structure from the front and back plate portions, the left and right side plate portions, and the bottom plate portion. The front and back plate portions are each provided with an inflow pipe portion and an outflow pipe portion.
[0051]
As shown in FIG. 2, the elution tank 39 has an aeration tube 45 for aerobing the electrodes 40 and 41, and a blower 46 arranged outside the tank for supplying air to the aeration tube 45. It is attached.
[0052]
The dephosphorization processing device D ₁ further includes a characteristic ion concentration detection unit 60 and a notification unit 63.
[0053]
The ion concentration detection unit 60 includes a detection tank 61 that is adjacent to the downstream side of the elution tank 39 in a communication manner, and a phosphate ion concentration sensor 62 disposed in the detection tank 61. The detection tank 61 stores treated water that has been electrolyzed and has flowed out of the elution tank 39. The phosphate ion concentration sensor 62 is immersed in treated water stored in a certain amount in the detection tank 61, and detects the concentration of phosphate ions in the treated water.
[0054]
The phosphate ion concentration sensor 62 includes an ion-sensitive film that holds an ion-sensitive substance made of a copper complex having one kind of chain diamine as a ligand.
[0055]
The notification unit 63 includes an LED lamp as a visual notification unit. The notification unit 63 notifies the inspection timing of the electrodes 40 and 41. That is, when the phosphate ion concentration detected by the phosphate ion concentration sensor 62 exceeds a predetermined value, the control unit 43 instructs the notification unit 63 to perform the notification. That is, when the phosphate ion concentration sensor 62 detects that the phosphate ion concentration exceeds a predetermined value and the detection result is input to the control unit 43, the control unit 43 notifies the notification unit 63 of the electrodes 40 and 41. An instruction to notify the inspection time is output.
[0056]
This will be described in more detail with reference to FIG. The treated water storage volume of the elution tank 39 is 500 milliliters. The flow rate of the treated water flowing into the elution tank 39 is 0.5 liter / minute, and the phosphate ion concentration is 15 mg / liter (5 mg / liter for the total phosphorus concentration TP). When the treated water flows into the elution tank 39, the electrodes 40 and 41 are energized. In normal operation, a current (constant current) is supplied to the electrodes 40 and 41 so that Fe / P = 1.0 to 2.0. In one example, a current of 381 mA is passed when Fe / P = 1.5.
[0057]
In this control, energization is performed for about 2 minutes after normal operation for a certain time (1 to 24 hours, in this example, 12 hours) (determined from the treated water storage capacity of the elution tank 39, the phosphate ion concentration stabilization time, etc.) ) Turn off. During the OFF time, the phosphate ion concentration C ₁ of the treated water stored in the detection tank 61 is measured by the phosphate ion concentration sensor 62.
[0058]
Thereafter, energization of the electrodes 40 and 41 is resumed. The energization current at this time is the same as in normal operation. Then, after about 5 minutes (determined from the treated water storage volume of the elution tank 39, the stable time of the phosphate ion concentration, the reaction time, etc.), the phosphate ion concentration sensor 62 is used to measure the phosphate ion concentration C of the treated water. Measure ₂
[0059]
Next, the control unit 43 compares the values of C ₁ and C ₂ . Then, if the _{(C 1 -C 2) / C} 1 is 0.8 or more, the control unit 43 to perform the normal operation certain period of instruction. On the other hand, if (C ₁ -C ₂ ) / C ₁ is less than 0.8, that is, if the phosphate ion concentration C ₂ after resuming energization exceeds a predetermined value, energization of the electrodes 40 and 41 is performed. Is turned off, and the notification unit 63 is instructed to turn on the LED lamp, thereby notifying that it is time to check the electrodes 40 and 41 (warning display ON).
[0060]
In the elution tank 39, iron ions Fe ²⁺ are dissolved from the electrodes 40 and 41, and oxygen is supplied into the treated water through the aeration tube 45. Fe ²⁺ is oxidized using dissolved oxygen to become Fe ³⁺ and sent to the contaminant removal tank 4, reacts with orthophosphoric acid PO ₄ ^3−, and is hardly soluble iron phosphate Fe (OH ) _X (PO ₄ ) _y . The iron phosphate salt Fe (OH) _x (PO ₄ ) _y aggregates with the SS content present in the contaminant removal tank 4 as a nucleus, becomes a large floc, precipitates, and accumulates at the bottom of the tank.
[0061]
Contaminants containing iron phosphate deposited on the bottom of the contaminant removal tank 4 are periodically (usually once a year) from the portion of the contaminant removal tank 4 where there is no anaerobic filter bed 7. Pumped out at a rate)
[0062]
Embodiment 2
Dephosphorization processing device D ₂ according to another one embodiment of the present invention, like the dephosphorization treatment device D ₁ of the above are incorporated into a small combined treatment septic tank as sewage treatment apparatus with a flow rate adjusting function Used (not shown).
[0063]
As shown in FIG. 4, between the power source 42 and the electrode 40 · 41 in the dephosphorization processing device D _2, distribution voltage sensor 53 in parallel as a voltage detection unit for detecting an inter-electrode voltage during electrolysis Has been. Configuration of other portions of the dephosphorization processing device D ₂ is similar to that of dephosphorization processing apparatus D _1.
[0064]
When the phosphate ion concentration detected by the phosphate ion concentration sensor 62 exceeds a predetermined value and the interelectrode voltage detected by the voltage sensor 53 is equal to or higher than the reference value, the control unit 43 informs the notification unit 63 of the LED lamp. Instruct lighting.
[0065]
This will be described in more detail with reference to FIG. When the treated water flows into the elution tank 39, the electrodes 40 and 41 are energized. In normal operation, a current is supplied so that Fe / P = 1.5. Then, after normal operation for a fixed time (12 hours), the phosphate ion concentration of the treated water stored in the detection tank 61 is measured by the phosphate ion concentration sensor 62.
[0066]
If the measured phosphate ion concentration is less than 1.0 mg / liter, the phosphate ion concentration is measured again after normal operation (standing time) for a fixed time (12 hours).
[0067]
On the other hand, if the measured phosphate ion concentration is 1.0 mg / liter or more, the operation is roughly divided into two. That is, when the ion concentration is 1.0 mg / liter or more and less than 9.0 mg / liter, a current is supplied so that Fe / P = 2.0. On the other hand, when the ion concentration is 9.0 mg / liter or more, a current is supplied so that Fe / P = 1.5 (when the phosphate ion concentration is 15 mg / liter, the current is supplied at 381 mA). .
[0068]
When the voltage between the electrodes detected by the voltage sensor 53 is 25 V (reference value) or more, the control unit 43 instructs the notification unit 63 to turn on the LED lamp, so that the inspection time of the electrodes 40 and 41 is reached. Notify that (warning display is ON). Further, when the phosphate ion concentration of the treated water stored in the detection tank 61 does not vary greatly with time, the phosphate ion concentration even if an electric current is applied so that Fe / P = 1.5 to 2.0, for example. Even when the value does not change compared to the initial value, the inspection time of the electrodes 40 and 41 is reached.
[0069]
【The invention's effect】
According to the first aspect of the present invention, it is possible to stably dissolve the electrode, and to easily know the inspection time of the electrode for electrode replacement or maintenance.
[0070]
According to the second aspect of the present invention, there is an effect that stable electrode dissolution can be performed, and the inspection time of the electrode for electrode replacement or maintenance can be easily determined.
[0071]
According to the invention of claim 3, the effect produced by the invention of claim 1 or 2 can be ensured by a simple and inexpensive member.
[0072]
According to the invention of claim 4, since the notification section is composed of at least one of a visual notification section and an auditory notification section, the effect produced by the invention of claim 1 or 2 is ensured by a simple and inexpensive member. be able to.
[0073]
According to the invention of claim 5, since the reference value of the interelectrode voltage is 25V, in addition to the effect produced by the invention of claim 2, the possibility of electric shock can be prevented.
[Brief description of the drawings]
FIG. 1 is a vertical longitudinal sectional view of a small merged treatment septic tank incorporating a dephosphorization processing apparatus according to one embodiment of the present invention.
2 is an enlarged vertical cross-sectional view of a part of the dephosphorization processing apparatus of FIG. 1;
FIG. 3 is a flowchart for explaining the operation of the dephosphorization processing apparatus of FIG. 1;
FIG. 4 is an enlarged vertical cross-sectional view of a part of a dephosphorization processing apparatus according to another embodiment of the present invention.
FIG. 5 is a flowchart for explaining the operation of the dephosphorization processing apparatus of FIG. 4;
[Explanation of symbols]
39 Elution tank 40 Electrode 41 Electrode 42 Power supply 43 Control unit 53 Voltage sensor (voltage detection unit)
60 Ion Concentration Detection Unit 61 Detection Tank 62 Phosphate Ion Sensor 63 Notification Unit

Claims (5)

At least a pair of electrodes for eluting iron ions or aluminum ions for removing phosphoric acid in the treated water, and an ion concentration detector for detecting the concentration of phosphate ions electrolyzed from these electrodes; And an informing unit for informing the inspection time of the electrode,
The sewage treatment apparatus, wherein the notification unit performs the notification when the concentration of phosphate ions detected by the ion concentration detection unit exceeds a predetermined value. At least a pair of electrodes for eluting iron ions or aluminum ions for removing phosphoric acid in the treated water, and an ion concentration detector for detecting the concentration of phosphate ions electrolyzed from these electrodes; An informing unit for informing the inspection time of the electrode, and a voltage detecting unit for detecting a voltage between the electrodes at the time of electrolysis,
In order to keep the amount of ions eluted from the electrode constant, the interelectrode voltage is increased according to the amount of ions, the concentration of phosphate ions detected by the ion concentration detector exceeds a predetermined value, and the voltage The sewage treatment apparatus, wherein the notification unit performs the notification when the voltage between the electrodes detected by the detection unit is equal to or higher than a reference value.   The sewage treatment apparatus according to claim 1 or 2, wherein the ion concentration detector comprises a detection tank for storing electrolyzed treated water and an ion concentration sensor disposed in the detection tank.   The sewage treatment apparatus according to claim 1 or 2, wherein the notification unit includes at least one of a visual notification unit and an auditory notification unit.   The sewage treatment apparatus according to claim 2, wherein the reference value of the voltage between the electrodes is 25V.

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