JPH10249387A - Sewage treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the easy execution of the maintenance of an ion supplying means by disposing an elution device for supplying the sewage in a treating vessel by eluting iron ions or aluminum ions from iron materials or aluminum to an opening for inspection in the treating vessel installed in the upper part of the treating vessel. SOLUTION: Miscellaneous household effluent flows from an inflow port 6 into a first anaerobic section 5 where the effluent is subjected to an anaerobic decomposition treatment. The effluent is then subjected to the similar treatment in a second anaerobic section 19 as well. The treated water obtd. in such a manner is sent to an aerobic section 23 where the water is subjected to an aerobic decomposition treatment. The sludge deposited on the bottom of the aerobic section 23 is returned together with the sludge in a setting section 29 of a post stage via a first return pipe 34 to the anaerobic section 5. Part of the treated water is returned via a third return pipe 46 to an elution tank 8. The elution tank 8 is arranged in the lower part of an opening 50 for inspection. The iron ions elated from an electrode 11 react with the orthogophoric acid existing in the elution tank 8 and are flocculated as a water- insoluble phosphorus compd. which is then successively returned from a discharge port 9 to the anaerobic section 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sewage treatment apparatus for purifying sewage, and more particularly to a sewage treatment apparatus for removing phosphorus from sewage.

[0002]

2. Description of the Related Art A sewage treatment apparatus of this type is known, for example, from Japanese Patent Application Laid-Open No. 7-108296 (C02F 3/30). Conventionally, as a method for removing phosphorus from sewage, an iron supply means for supplying iron ions to sewage or an elution device for eluting iron ions reacts iron ions supplied to the sewage with phosphorus in the sewage to convert the phosphorus into water There has been known a method of removing phosphorus by coagulation and precipitation as an insoluble phosphorus compound.

[0003] The sewage treatment apparatus described in the above publication is
The treated water in the aerobic tank has a fibrous or flocculent electrode,
Form a return route to return to the anaerobic tank via an elution device that elutes iron ions, react iron ions eluted in the return route and in the anaerobic tank with phosphorus in sewage, and aggregate phosphorus as a water-insoluble phosphorus compound , Precipitates and removes phosphorus from the treated water.

However, despite the necessity of maintenance such as replacement of electrodes due to elution of iron ions,
No consideration was given to the disposition of the elution device, and maintenance workability such as electrode replacement was poor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a sewage treatment apparatus capable of easily maintaining ion supply means for supplying iron ions or aluminum ions to sewage. That is the task.

[0006]

A first means for solving the above problems is to provide a processing tank having an anaerobic part, an aerobic part, and a sedimentation part, and to inspect the inside of the processing tank provided on the upper part of the processing tank. And an ion supply means for supplying iron ions or aluminum ions to sewage in the treatment tank is provided near the inspection opening. Features.

In the first means, it is preferable that the inspection opening and the ion supply means are provided above the anaerobic section.

In the first means, it is preferable that an opening for supplying ions is formed on an upper surface of the ion supply means, and the opening is provided above sewage in the treatment tank.

A fourth means for solving the above problems is as follows.
Anaerobic part, a treatment tank having an aerobic part and a sedimentation part, and an elution device that elutes iron ions or aluminum ions from iron material or aluminum and supplies the wastewater in the treatment tank,
An inspection opening in the processing tank provided at the top of the processing tank,
A lid for opening and closing the inspection opening, and the elution device is disposed near the inspection opening.

[0010] A fifth means for solving the above problems is as follows.
A treatment tank having an anaerobic part, an aerobic part and a sedimentation part, an elution device for eluting iron ions or aluminum ions from the iron material or aluminum, and a return for returning wastewater in the treatment tank to the treatment tank via the elution device Means, an inspection opening in the processing tank provided at the upper portion of the processing tank, and a lid for opening and closing the inspection opening, and the elution device is disposed near the inspection opening. It is characterized by.

In the fourth means or the fifth means, it is preferable that the inspection opening and the elution tank are provided above the anaerobic part.

In the fourth means or the fifth means, it is preferable that an opening for supplying an iron material or aluminum is formed on an upper surface of the elution device, and the opening is provided above the wastewater in the treatment tank. .

In the above-mentioned fourth means or the fifth means, the eluting device has an electrode made of iron or aluminum, is provided with a means for detecting the opening and closing of the lid, and outputs the output of the lid opening detecting means. It is preferable to provide control means for shutting off the power supply to the electrode when the lid is opened based on this.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail below based on a sewage treatment apparatus shown in FIGS.

Reference numeral 1 denotes a treatment tank buried underground. The processing tank 1 has a first partition 2, a second partition 3, and a third partition 4, which form a first anaerobic section 5, a second anaerobic section 19,
It is divided into an aerobic part 23, a sedimentation part 29 and a disinfection part 31.

Reference numeral 5 denotes a first anaerobic section having an inlet 6 into which household wastewater flows, and reference numeral 7 denotes a first anaerobic filter bed provided in the first anaerobic section 5, which flows into the first anaerobic section 5. In addition to sedimentation and separation of hardly decomposable contaminants mixed in the waste water, the organic substances are anaerobically decomposed by the anaerobic microorganisms attached to the first anaerobic filter bed 7. It also anaerobically decomposes organic nitrogen into ammonia nitrogen.

Reference numeral 8 denotes a rectangular box-shaped elution tank disposed above the sewage in the first anaerobic section 5 and facing a first inspection opening 50 described later. 9. Reference numeral 10 denotes an electrode cover formed of a transparent insulator that has an electrode 11 made of an iron material disposed in the elution tank 8 and that closes the elution tank 8.

Reference numeral 12 is controlled by a control circuit 58 described later.
The power supply device supplies a constant DC current between the electrodes 11. By applying a DC constant current supplied from a power supply 12 between the electrodes 11, iron ions are eluted from the electrodes 11 and the elution tank 8
Supply iron ions inside. Reference numeral 13 denotes a vent provided in the upper part of the elution tank 8 for discharging hydrogen gas generated by electrolysis of the electrode 11 to the outside of the elution tank 8. The elution device 14 is composed of the elution tank 8, the electrode 11, and the power supply device 12.

Reference numeral 15 denotes a first air diffuser disposed between the electrodes 11 at the bottom of the elution tank 8, which forms a number of air outlets and is connected to the first blower 16. By discharging the supplied air from the air outlet, the electrode 11 is washed to prevent sludge from adhering, and the divalent iron ions eluted from the electrode 11 react with orthophosphoric acid.
Oxidizes to monovalent iron ions.

Reference numeral 17 denotes a first anaerobic part 5 disposed in the first anaerobic part 5.
The treated water decomposed anaerobically in the first anaerobic section 5 is supplied to a second anaerobic section 19 to be described later through a first water supply port 18 penetrating the upper portion of the first partition wall 2 by an advection pipe.

Reference numeral 19 denotes a first anaerobic section 5 formed by the first partition wall 2.
The second anaerobic section 20 is a second anaerobic filter bed disposed in the second anaerobic section 19, and the second anaerobic filter bed 20 captures suspended matter and removes organic matter by anaerobic microorganisms. It anaerobically decomposes organic nitrogen into ammonia nitrogen while anaerobically decomposing.

Reference numeral 21 denotes a second anaerobic part 19
The treated water decomposed anaerobically in the second anaerobic section 19 is supplied to the aerobic section 23 to be described later through the second water supply port 22 penetrating the upper part of the second partition wall 3 by the advection pipe. Reference numeral 23 denotes an aerobic section defined by the second partition wall 3 as a second anaerobic section 19,
The anaerobic treated water flows in through the second advection pipe 21. Reference numeral 24 denotes a contact material provided in the aerobic part 23, which promotes the culture of aerobic microorganisms.

Numeral 25 denotes a second air diffuser disposed at the bottom of the aerobic part 23, which forms a number of air outlets and is connected to the second blower 26 to supply air supplied from the second blower 26. The air is discharged from the air outlet to maintain the inside of the aerobic part 23 in an aerobic state, and the treated water is aerobically decomposed by aerobic microorganisms,
Ammonia nitrogen is decomposed into nitrate or nitrite nitrogen by the action of nitrate or nitrite.

Reference numeral 27 denotes a third air diffuser disposed below the contact member 24 and having a large number of air outlets.
Is connected to The air supply from the second blower 26 can be switched to either the second diffuser 25 or the third diffuser 27 by a first solenoid valve 28 controlled by a control circuit 58 described later.

The first solenoid valve 28 normally switches to the second air diffuser 25 and discharges the air supplied from the second blower 26 from the air outlet of the second air diffuser 25 to clean the inside of the aerobic part 23. When the contact material 24 is washed, the air supply from the second blower 26 is switched to the third diffuser 27 and the third diffuser 27 is maintained.
The air is released from the air outlet of the biofilm, and the biofilm that has adhered to the contact material 24 and multiplied and gradually thickened is peeled off.

Reference numeral 29 denotes a sedimentation section partitioned by the third partition wall 4 from the aerobic section 23. The sedimentation section 29 is provided at the bottom of the third partition wall 4 and flows in from a communication port 30 for communicating the aerobic section 23 and the sedimentation section 29. Then, the treated water aerobically decomposed in the aerobic part 23 is separated into a precipitate and a supernatant. Further, in order to return the sediment deposited on the bottom of the sedimentation section 29 from the communication port 30 to the aerobic part 23, the bottom of the sedimentation part 29 is aerobic part.
It is inclined to the 23 side.

Reference numeral 31 denotes a disinfecting section provided above the settling section 29,
The supernatant separated in the precipitation section 29 flows in. Numeral 32 denotes a sterilizer provided in the disinfection unit 31. The disinfection unit 32 is provided by a chlorine-based chemical or the like provided in the sterilizer 32.
Disinfect the treated water that has flowed into the facility. Reference numeral 33 denotes a drain port communicating with the disinfecting section 32, which drains the treated water disinfected in the disinfecting section 32 out of the treatment tank 1.

Reference numeral 34 denotes a first return pipe which communicates the bottom of the aerobic section 23 with the upper part of the first anaerobic section 5. Reference numeral 35 denotes a fourth air diffuser disposed in the first return pipe 34 at the bottom of the aerobic part 23, which forms a number of air outlets and is connected to the third blower 36;
By discharging the air supplied from the third blower 36 from the air outlet, the sludge deposited on the bottom of the aerobic part 23 and the sediment returned to the aerobic part 23 from the sedimentation part 29 are transferred to the first return pipe. The air is sucked into 34 and returned to the first anaerobic section 5.

Reference numeral 37 denotes a second return pipe which communicates the upper part of the sedimentation section 29 with an inflow chamber 41 of a water dividing and measuring apparatus 40 described later. Reference numeral 38 denotes a fifth air diffuser provided in the second return pipe 37, which forms a number of air outlets and is connected to the third blower 36. The air supply from the third blower 36 can be switched to either the fourth diffuser 35 or the fifth diffuser 38 by a second solenoid valve 39 controlled by a control circuit 58 described later.

The second solenoid valve 39 normally switches to the fifth air diffuser 38 and discharges the air supplied from the third blower 36 from the air outlet of the fifth air diffuser 38 to thereby settle the sedimentation section 29.
The supernatant liquid inside is sucked into the second return pipe 37, and is transferred to the inflow chamber 41 of the water distribution measuring device 40 described later.

After cleaning the contact material 24, the air supply from the third blower 36 is switched to the fourth air diffuser 35, and the air is discharged from the air outlet of the fourth air diffuser 35, whereby the aerobic part 23 is released. The treated water flows through the first return pipe 34 into the first anaerobic bed tank 5. The sludge deposited at the bottom of the aerobic part 23 and the sediment returned to the aerobic part 23 from the sedimentation part
It is sucked into the return pipe 34 and returned to the first anaerobic bed tank 5.

Numeral 40 denotes a rectangular box-shaped water measuring device arranged above the sedimentation section 29, which adjusts the amount of the supernatant liquid transferred by the second return pipe 37 to the elution tank 8 to a predetermined amount. I can do it. The water measuring device 40 is a second return pipe.
An inflow chamber 41 connected to the inflow chamber 37, and an intermediate chamber 43 partitioned by a partition wall 42 having an opening communicating the inflow chamber 41 with the lower side.
And a first water separation chamber 44 and a second water separation chamber 45 into which the treated water in the intermediate chamber 43 flows.

The first water separation chamber 44 includes an elution tank 8 and a third return pipe.
In addition to communicating with the intermediate chamber 43, the upper part of the wall is communicated with the intermediate chamber 43 by a notch 47 having a V-shaped opening. The second water diversion chamber 45 communicates with the upper part of the aerobic part 23 by a pipe 48, and communicates with the intermediate chamber 43 by an opening formed at an upper part of an overflow weir plate 49 whose height can be adjusted.

The height of the overflow weir plate 49 is adjusted to adjust the overflow weir plate 49.
The size of the opening formed in the upper part of the
By setting the amount of treated water to be returned to the aerobic section 23, the amount of treated water flowing into the elution tank 8 from the first water separation chamber 44 can be adjusted.

Reference numeral 50 denotes a first inspection opening provided at a position facing the first anaerobic section 5, the second anaerobic section 19, and the elution tank 8 of the elution device 14 above the first partition wall 2, and 51 denotes the first inspection opening. A reed switch provided in the inspection opening 50 detects an open / closed state of a first lid 52 described later. Reference numeral 52 denotes a first lid for closing the first inspection opening 50 so as to be openable and closable, and reference numeral 53 denotes a magnet provided on the first lid 52 for turning on and off the reed switch 51. The first lid 52 is positioned such that the magnet 53 of the first lid 52 always faces the reed switch 51.
The lid 52 is positioned by positioning means (not shown).

The first lid 52 opens and closes when the sludge deposited on the bottoms of the first anaerobic section 5 and the second anaerobic section 19 is eliminated and the electrode 11 of the elution device 14 is maintained.
When the first lid 52 is opened, the reed switch 51 is turned off. Based on this signal, the control circuit 58 stops the power supply device 12 and activates the power supply device 12 when the first lid 52 is attached.

Reference numeral 54 denotes a second inspection opening provided at a position facing the aerobic portion 23, and reference numeral 55 denotes a second lid which closes the second inspection opening 54 so that it can be opened and closed. Reference numeral 56 denotes a third inspection opening provided at a position facing the sterilization device 32, and reference numeral 57 denotes a third lid that closes the third inspection opening 56 so as to be openable and closable. It opens and closes when refilling.

Reference numeral 58 denotes the first blower 16 and the second blower 2
6, a control circuit for controlling the third blower 36, the power supply device 12, the first solenoid valve 28, the second solenoid valve 39, and the like.

Thus, the household wastewater discharged from the house flows into the first anaerobic section 5 through the inlet 6. The first anaerobic filter bed 7 disposed in the first anaerobic section 5 removes relatively coarse solids and contaminants such as toilet paper in household wastewater, and removes them in each treatment tank flowing in later. Preliminary treatment for smooth treatment is performed, and at the same time, the removed solids, contaminants, and sewage passing through the first anaerobic filter bed 7 are anaerobically decomposed by the action of anaerobic microorganisms, and the BOD is reduced. Sludge generated by the decomposition of the sewage accumulates at the bottom of the first anaerobic section 5. It also anaerobically decomposes organic nitrogen into ammonia nitrogen.

The treated water decomposed anaerobically in the first anaerobic section 5 by the new domestic wastewater flowing into the first anaerobic bed tank 7 flows from the first water supply port 18 of the first advection pipe 17 to the second anaerobic section 19. Inflow. The treated water that has flowed into the second anaerobic section 19 is
Anaerobically decomposes organic matter by the action of anaerobic microorganisms
D is reduced, and the sludge generated by the decomposition of the sewage accumulates at the bottom of the second anaerobic section 19. It also anaerobically decomposes organic nitrogen into ammonia nitrogen.

The treated water anaerobically decomposed in the second anaerobic filter bed 20 by the new treated water flowing into the second anaerobic section 19 is supplied to the second advection pipe.
The air flows into the aerobic part 23 from the second water supply port 22 of the air conditioner 21. The treated water that has flowed into the aerobic part 23 is stirred by the air supplied from the second blower 26 being discharged from the air outlet of the second air diffuser 25.

Further, oxygen is dissolved in the treated water, and the treated water is aerobicly decomposed by the action of a large number of aerobic microorganisms attached to the surface of the contact material 24, and organic phosphates and the like are decomposed into orthophosphoric acid, and ammonia Decomposes nitrogen into nitrate and nitrite nitrogen. Further, the sludge generated by the decomposition of the sewage accumulates on the bottom of the aerobic part 23.

The freshly treated water flowing into the aerobic part 23 causes the treated water aerobicly decomposed by the action of the aerobic microorganisms attached to the contact material 24 to pass through the communication port 30 at the bottom of the aerobic part 23 to the sedimentation part.
Flow into 29. The treated water flowing into the sedimentation section 29 is
While rising inside, the sedimentable substance settles and is returned from the communication port 30 to the aerobic part 23, and the supernatant liquid flows into the disinfecting part 31. The supernatant liquid flowing into the disinfecting section 31 is disinfected by a disinfecting device 32 equipped with a chlorine-based chemical and kills bacteria such as pathogenic bacteria,
The water is drained out of the treatment tank 1 through the drain 33.

The air supplied from the third blower 36 is
By discharging from the air outlet of the diffuser 38, the sedimentation section
The supernatant liquid in 29 flows into the inflow chamber 41 of the water separation measuring device 40,
The water is rectified in the intermediate chamber 43 and flows into the first water diversion chamber 44 and the second water diversion chamber 45.

The height of the overflow weir plate 49 is adjusted, and the second water diversion chamber 45 is adjusted.
By changing the size of the opening formed above the overflow weir plate 49 that communicates with the intermediate chamber 43, the amount of water returned from the second water diversion chamber 45 to the aerobic part 23 is determined. The amount of treated water flowing into the elution tank 8 from the water chamber 44 can be adjusted to a predetermined amount.

The treated water that has flowed into the elution tank 8 from the first water separation chamber 44 via the third return pipe 46 receives the iron eluted from the electrode 11 by applying a DC constant current between the electrodes 11 made of iron material. Ions are supplied. The eluted iron ions react with the orthophosphoric acid present in the elution tank 8, aggregate and precipitate as a water-insoluble phosphorus compound, and are returned from the outlet 9 to the first anaerobic section 5. The iron ions in the treated water returned to the first anaerobic section 5 react with orthophosphoric acid present in the first anaerobic section 5 and aggregate and precipitate as a water-insoluble phosphorus compound.

The nitrate or nitrite nitrogen in the treated water returned to the first anaerobic section 5 is reduced by the denitrifying bacteria present in the first anaerobic section 5 in a large amount, and diffused into the air as nitrogen gas. Removed.

The treated water returned from the elution tank 8 to the first anaerobic section 5 is supplied not from the aerobic section 23 where the dissolved oxygen concentration is extremely high but from the sedimentation section 29. Even if the treated water is returned to the first anaerobic section 5, anaerobic treatment can be performed with little influence on anaerobic microorganisms.

Since the biofilm formed by the aerobic microorganisms attached to the contact material 24 grows and gradually thickens, the control circuit 58 controls the first solenoid valve 28 periodically to prevent clogging. The air supply from the second blower 26 is switched to the third air diffuser 27, and air is released from the air outlet of the third air diffuser 27 to peel off the biofilm.

When the supply of air from the third air diffuser 27 is completed, the separated biofilm is deposited on the bottom of the aerobic part 23. However, the control circuit 58 controls the second solenoid valve 39 to transmit the air from the third blower 36. By switching the air supply to the fourth air diffuser 35 and discharging the air from the air outlet of the fourth air diffuser 35, the treated water in the aerobic part 23 is supplied to the first anaerobic part 5 via the first return pipe. Flows into. With this flow, the sludge deposited on the bottom of the aerobic section 23 and the sediment returned from the sedimentation section 29 to the aerobic section 23 are returned to the first anaerobic section 5 via the first return pipe 34.

The elution tank 8 of the elution device 14 has a first inspection opening 50.
The elution device can be inspected when the first lid 52 is opened and the sludge accumulated in the first anaerobic section 5 and the second anaerobic section 19 is removed by suction. Further, when the first lid 52 is opened, the control circuit 58 stops only the power supply device 12 and the devices other than the power supply device 12 are continuously operated. Therefore, the operation of the sewage treatment device and the sewage treatment status are confirmed. And prevent electric shock during maintenance of the dissolution apparatus.

Further, the discharge port 9 is disposed at the bottom of the elution tank 8, and when the third blower 36 is stopped, all the treated water flowing into the elution tank 8 is discharged from the discharge port 9 to the first anaerobic section. Since the electrode 11 is returned to the terminal 5 and the electrode 11 is exposed, the state of the electrode 11 can be easily confirmed through the transparent electrode cover 10 without touching the electrode 11. Furthermore, since the water-insoluble phosphorus compound that has aggregated and precipitated in the elution tank 8 is returned to the first anaerobic section 5 from the discharge port 9, the sludge treatment in the elution tank 8 does not need to be performed.

In the embodiment of the present invention, when the electrode 11 made of an iron material is immersed in the treatment water in the elution tank 8 for a long time, an oxide film is generated on the electrode surface, and the electrode 11 is in a passivated state. The elution of ions gradually decreases, and the dephosphorization performance decreases.

Therefore, it is preferable that a constant DC current is applied between a pair of electrodes made of an iron material, and the polarity of the current is changed every predetermined time. An oxide film is formed on the surface of the iron material on the anode side when used for a long period of time, but the surface of the iron material on the cathode side is cleaned by hydrogen gas generated from the iron material on the cathode side, and no oxide film is formed. Therefore, the elution of iron ions can be maintained substantially constant by changing the polarity at a time interval until an oxide film is formed on the iron material surface on the anode side and the elution of iron ions is reduced, and the phosphorus removal performance can be maintained. Can be kept constant.

In this configuration, since both electrodes are made of an iron material, iron ions are always eluted from the iron material serving as the anode side electrode and supplied to the treated water, so that the dephosphorization performance is always maintained at a constant state. can do.

It is also possible to adopt a configuration in which an iron material is used at least on the anode side of the electrode, a DC constant current is applied between both electrodes, and the applied current is increased in a pulsed manner at predetermined time intervals. In this configuration, by increasing the applied current in a pulsed manner, the oxide film generated on the surface of the iron material on the anode side can be peeled off, and the elution of iron ions is kept almost constant, and the dephosphorization performance is kept constant. Can be maintained.

Further, a configuration may be adopted in which a DC constant current is applied between a pair of electrodes made of an iron material, the polarity of the current is changed every predetermined time, and the applied current is increased in a pulsed manner. If the time required for the polarity change is long, an oxide film is formed on the iron material surface on the anode side, and by changing the polarity, the oxide film can be washed and removed with a hydrogen gas. Some time is required until the oxide film is peeled off, and the electric resistance until the oxide film is peeled off is large, which may increase power consumption.

Accordingly, the oxide film on the surface of the iron material converted from the anode to the cathode can be removed in a short time by increasing the applied current in a pulsed manner as described above, and an increase in power consumption can be prevented.

In the embodiment of the present invention, an iron material is used for both electrodes as an electrode for applying a DC constant current to elute iron ions. However, an iron material is used for the anode electrode, and a titanium electrode is used for the cathode electrode. Alternatively, a configuration using an insoluble material such as platinum or platinum may be used.

In the embodiment of the present invention, an iron material is used for both electrodes as an electrode for applying a DC constant current to elute iron ions. However, a structure using aluminum may be used.

Further, in the embodiment of the present invention, the elution tank 8 of the elution device 14 is disposed so as to face the first inspection opening 50. However, the elution tank 8 is disposed in the second inspection opening 54 or the third inspection opening 56. The elution tank 8 of the elution device 14 may be arranged so as to face.

[0062]

According to the first aspect of the present invention, the inspection and repair of the ion supply means can be easily performed only by opening the lid, and effects such as easy maintenance can be obtained. .

According to the configuration of the second aspect of the present invention, when sludge treatment of the anaerobic section is performed, inspection and repair of the ion supply means can be performed, and effects such as easy maintenance can be obtained. .

According to the configuration of the third aspect of the present invention, it is possible to easily supply ions to the ion supply means simply by opening the lid, and to achieve effects such as easy maintenance.

According to the configuration of the fourth aspect of the present invention, the inspection and repair of the dissolution apparatus can be easily performed only by opening the lid, and effects such as easy maintenance can be obtained.

According to the configuration of the fifth aspect of the present invention, the inspection and repair of the dissolution apparatus can be easily performed only by opening the lid, and effects such as easy maintenance can be obtained.

According to the configuration of claim 6 of the present invention, when sludge treatment of the anaerobic part, the elution device can be inspected and repaired, and effects such as easy maintenance can be obtained.

According to the configuration of claim 7 of the present invention, it is possible to easily perform electrode replacement simply by opening the lid, and to achieve effects such as easy maintenance.

According to the eighth aspect of the present invention, since the power of the dissolution apparatus is turned off just by opening the lid, it is possible to prevent electric shock at the time of inspection and repair.

[Brief description of the drawings]

FIG. 1 is a sectional view of a sewage treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view as viewed from another direction.

FIG. 3 is an enlarged sectional view of the elution device.

FIG. 4 is a perspective view of the same water measuring device.

[Explanation of symbols]

 1 Treatment tank 5 First anaerobic part (anaerobic part) 23 Aerobic part 29 Sedimentation part 50 First inspection opening 52 First lid 54 Second inspection opening 55 Second lid 56 Third inspection opening 57 Third Lid 58 Control circuit (control means)

Claims (8)

[Claims] 1. A processing tank having an anaerobic part, an aerobic part, and a sedimentation part, an opening for inspection in a processing tank provided at an upper part of the processing tank, and a lid for closing the opening for opening and closing freely. With
A sewage treatment apparatus, wherein an ion supply means for supplying iron ions or aluminum ions to sewage in the treatment tank is provided near the inspection opening. 2. The sewage treatment apparatus according to claim 1, wherein the inspection opening and the ion supply means are provided above the anaerobic section. 3. The sewage treatment apparatus according to claim 1, wherein an opening for supplying ions is formed on an upper surface of the ion supply means, and the opening is provided above sewage in the treatment tank. . 4. A treatment tank having an anaerobic part, an aerobic part, and a sedimentation part, an elution device that elutes iron ions or aluminum ions from iron material or aluminum and supplies it to sewage in the treatment tank, and an upper part of the treatment tank. A sewage treatment apparatus, comprising: an inspection opening in a treatment tank provided in the water tank; and a lid for opening and closing the inspection opening, and the dissolving device is disposed near the inspection opening. . 5. A treatment tank having an anaerobic part, an aerobic part, and a sedimentation part, an elution device for eluting iron ions or aluminum ions from the iron material or aluminum, and treating wastewater in the treatment tank via the elution device. A return means for returning to the tank, an inspection opening in the processing tank provided at the upper part of the processing tank, and a lid for opening and closing the inspection opening freely,
A sewage treatment apparatus, wherein the dissolution device is disposed near the inspection opening. 6. The sewage treatment apparatus according to claim 4, wherein the inspection opening and the elution tank are provided above the anaerobic section. 7. An opening for supplying an iron material or aluminum is formed on an upper surface of the elution device, and the opening is provided above sewage in the treatment tank.
Or the sewage treatment apparatus according to claim 5. 8. The elution device has an electrode made of iron or aluminum, is provided with means for detecting opening and closing of the lid, and supplies power to the electrode when the lid is opened based on an output of the lid opening detecting means. The sewage treatment apparatus according to claim 4 or 5, further comprising control means for shutting off the water.