KR100404947B1 - device for treatment of sewage and coagulator - Google Patents

Abstract

The tank 1 is composed of a first anaerobic tank (5), a second anaerobic tank (10), a contact vent (14), a treatment tank (19), a disinfection tank (21) and an electrolytic bath (37). It is provided with, and is covered by the manhole (28). The electrolytic cell 37 is equipped with electrodes 41 and 42. Electrolysis of the electrodes 41 and 42 causes metal ions to be supplied to the first anaerobic filter. The electrodes 41 and 42 are attached to the manhole 28.

Description

Sewage treatment device and coagulation sedimentation device {device for treatment of sewage and coagulator}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment apparatus and a flocculation sedimentation apparatus, and more particularly, to a sewage treatment apparatus and a flocculation sedimentation apparatus in which phosphorus components in treated water are precipitated as water-soluble metal salts.

The conventional sewage treatment apparatus includes an electrode, and the metal ions generated by electrolysis of the electrode cause the phosphorus component in the treated water to precipitate as a metal salt that is poorly soluble in water. In such a wastewater treatment apparatus, the electrode was provided in the electrolytic cell. The electrolyzer in the conventional wastewater treatment apparatus is typically shown in FIG.

Referring to Fig. 38, the electrolytic cell 800 is provided with electrodes 801 and 802 provided therein, and an introduction port 803 through which treated water is introduced. The electrodes 801 and 802 are respectively connected to a power supply, and either side is electrolyzed by energizing. The metal ion produced by this electrolysis reacts with the phosphorus component in the treated water introduced from the inlet port 803 to become a metal salt which is poorly soluble in water. The electrolytic cell 800 is provided with a valve 805 at its bottom. By appropriately operating the valve 805, the metal salt is discharged out of the electrolytic cell 800.

However, in the conventional sewage treatment apparatus, there is a problem that the metal salt is not sufficiently discharged from the electrolytic cell 800 and the electrolysis is inhibited by the metal salt.

In the conventional sewage treatment apparatus, the electrolytic cell 800 may be installed in another tank into which the daily waste water is introduced. And the metal salt discharged out of the electrolytic cell 800 precipitated with the sludge settled in the said other tank. When a metal salt precipitates with sludge, recycling of phosphorus from the metal salt becomes difficult. This has been a problem for gowns that have increased demand for phosphorus recycling.

In addition, some conventional flocculation settling devices include a flocculation tank and a flocculation settling tank in order to flocculate and settle the phosphorus component and the like in the treated water as metal salts which are poorly soluble in water. 39, the block diagram for demonstrating the flow of a process in the sewage treatment apparatus containing the conventional flocculation sedimentation apparatus is shown.

Referring to Fig. 39, the wastewater is circulated in the order of the intermediate flow rate adjustment tank 901, the coagulation tank 902, the coagulation sedimentation tank 903, and the sterilization tank 904. The sewage treated in each tank is discharged from the sterilization tank 904.

In the flocculation tank 902, a drug for supplying iron ions or aluminum ions to the effluent is introduced as a flocculant in order to aggregate the predetermined components of the filthy water. By inputting such a drug, it is possible to aggregate and remove the phosphorus component from the sewage, and also lower the biological oxygen demand (BOD) value, the suspended substance (SS) value, and the chemical oxygen demand (COD) value of the sewage. BOD is represented by replacing the amount of organic matter decomposed by the microorganism with the amount of oxygen. SS represents the quantity of the particle | grains etc. which are suspended, and are not dissolved in water. COD is an index indicating the degree of dirt of water in the sea area and the like, and indicates the amount of organic matter that can be oxidized by an oxidizing agent.

After mixing with the flocculant in the flocculation tank 902, the sewage is introduced into the flocculation settling tank 903 together with the prog produced in the flocculation tank 902. The floc introduced from the flocculation tank 902 is settled in the flocculation settling tank 903, and the symbol of the flocculation settlement tank 903 is introduced into the sterilization tank 904, and after disinfection is appropriately discharged.

However, in the flocculation sedimentation apparatus shown in FIG. 39, since the chemical | medical agent injected as a flocculant is an acidic solution, the operation | work for flocculation is dangerous, and in order to flocculate, it is necessary to adjust pH in the flocculation tank 902, and to remove a phosphorus component reliably. It was difficult.

In general, agglomerates of phosphorus compounds in sewage treatment devices and flocculation sedimentation devices are often in the form of fine particles. Also from this point, it was difficult to reliably remove the aggregated phosphorus compound from the treated water.

Summary of the Invention

Therefore, the present invention has been conceived in view of such circumstances, and one of the objects is to provide a sewage treatment apparatus and a flocculation sedimentation apparatus which can reliably remove the phosphorus compound from the treated water.

Another object of the present invention is to recover more phosphorus compounds in a state capable of being recycled.

Further, another object of the present invention is to provide a sewage treatment apparatus and a flocculation sedimentation apparatus which can safely aggregate certain components such as phosphorus in sewage.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the sewage treatment system containing the sewage treatment apparatus which is 1st Embodiment of this invention.

FIG. 2 is a diagram showing a detailed configuration of the electrolytic cell of FIG. 1 and its vicinity.

3 is a view showing the structure of the electrode and the electrode support of FIG.

4 is a view showing a state in which the electrode and the electrode support of FIG. 3 are combined to be mounted on an electrolytic cell.

5 is a perspective view of the electrode support of FIG. 3.

6 is a perspective view of the electrolytic cell of FIG. 1.

FIG. 7 is a view showing an electrode support portion that can support two electrodes and has a notch portion. FIG.

8 is a view showing a state in which the unitized electrode and the electrode support are accommodated in the case.

It is a figure which shows the sewage treatment apparatus which is 2nd Embodiment of this invention.

It is a figure which shows the sewage treatment apparatus which is 3rd Embodiment of this invention.

FIG. 11 is a side view of the membrane and magnet of FIG. 10.

12 is a partial perspective view of the magnet of FIG. 10.

It is a figure which shows the sewage treatment apparatus which is 4th Embodiment of this invention.

It is a figure which shows the sewage treatment apparatus which is 5th Embodiment of this invention.

It is a figure which shows the sewage treatment apparatus which is 6th Embodiment of this invention.

It is a figure which shows the sewage treatment apparatus which is a 7th embodiment of this invention.

FIG. 17 is a view for explaining a mounting mode of a manhole of the electrode of FIG. 16. FIG.

It is a longitudinal cross-sectional view of the sewage treatment system containing the sewage treatment apparatus which is 8th Embodiment of this invention.

19 is a cross-sectional view of the tank shown in FIG. 18.

20 is a perspective view of an electrolytic unit of the sewage treatment system of FIG.

21 is an exploded perspective view of the electrolytic unit of the sewage treatment system of FIG.

It is a longitudinal cross-sectional view of the sewage treatment system containing the sewage treatment apparatus which is 9th Embodiment of this invention.

FIG. 23 is a cross-sectional view of the phosphorus recovery unit of the sewage treatment system of FIG. 22.

24A and 24B are flowcharts showing the flow of processing in the combined purification tank including the flocculation sedimentation apparatus of the tenth and eleventh embodiments of the present invention.

FIG. 25 is a flowchart showing a modification of the process surrounded by the broken lines R in FIGS. 24A and 24B.

It is a figure which shows the external appearance of a part of merger purification tank containing the flocculation settling apparatus of 10th Embodiment of this invention.

FIG. 27 is an exploded perspective view of the electrolytic cell of FIG. 26.

28 is a perspective view of the electrode pair of FIG. 27.

FIG. 29 is an exploded perspective view of the electrode pair of FIG. 27 partially broken; FIG.

FIG. 30 is a partially broken exploded perspective view of the electrode pair of FIG. 28.

FIG. 31 is a partially broken exploded perspective view of the electrode pair of FIG. 28.

Fig. 32 is a front view of a sedimentation measuring instrument used for determining the residence time of sewage in an electrolytic cell according to a tenth embodiment of the present invention.

[Fig. 33] A diagram showing the removal rate of phosphorus in artificial liquid at each depth of the sedimentation measuring instrument of Fig. 32.

FIG. 34 is a diagram showing the removal rate of phosphorus in artificial liquid at each depth of the sedimentation measuring instrument of FIG. 32.

FIG. 35 is a diagram showing the removal rate of phosphorus in artificial liquid at each depth of the sedimentation measuring instrument of FIG. 32.

FIG. 36 is a diagram showing the removal rate of phosphorus in artificial liquid at each depth of the sedimentation measuring instrument of FIG. 32.

Fig. 37 is an exploded perspective view of the electrolytic unit accommodated in the flocculation tank of the eleventh embodiment of the present invention.

38 is a diagram schematically showing an electrolytic cell of a conventional sewage treatment apparatus.

39 is a block diagram for explaining the flow of treatment in a sewage treatment apparatus including a conventional flocculation settling apparatus.

* Description of the symbols for the main parts of the drawings *

Reference numerals 1 tank 2 first partition wall 3 second partition wall

4: third partition wall 5: first anaerobic filter

6 inlet port 7 first anaerobic phase 8 first flow pipe

9: first water inlet 10: second anaerobic phase 11: first anaerobic phase

12. Second advection pipe 13 Second supply port 14 Contact plating tank

16: 1st diffuser 17: 1st blower 18: 1st pump

19: treatment tank 20: communication port 21: disinfection tank

22 sterilizer 23 drain port 24 first conveying pipe

28 manhole 32 ejection device 37 electrolytic cell

40: third diffuser 41, 42: electrode

The sewage treatment apparatus according to an aspect of the present invention is a sewage treatment apparatus for treating sewage, and includes a sewage treatment unit for receiving sewage, and the sewage treatment unit includes adsorption means made of a magnetic member.

According to the present invention, the aggregate of the phosphorus compound generated in the sewage treatment unit can be magnetically adsorbed to the adsorption member.

Therefore, a phosphorus compound can be reliably removed from wastewater.

In addition, the sewage treatment apparatus according to the present invention, the sewage treatment unit is provided with an active sludge housing the activated sludge, and a filter for filtering the treated water in the active sludge, the adsorption means is preferably installed in the vicinity of the filter. .

As a result, aggregates of the phosphorus compound are adsorbed on the adsorption member, and it can be avoided that causes clogging of the filter.

In addition, in the sewage treatment apparatus according to the present invention, the adsorption means is preferably provided integrally with the filter.

Thereby, the aggregate of the phosphorus compound in the vicinity of a filter can be made to adsorb | suck to a adsorption member more reliably. Thereby, clogging of the filter by the aggregate of the phosphorus compound can be more reliably avoided.

In addition, the sewage treatment apparatus according to the present invention further includes an ion supply unit for supplying iron ions or aluminum ions to the sewage treatment unit, and the sewage treatment unit may contain aggregates formed by reacting iron or aluminum ions supplied from the ion supply unit with the treated water. It is preferably provided with a settling tank for settling, and the adsorption means is preferably installed in the settling tank.

Thereby, a phosphorus compound can be made to adsorb | suck to an adsorption member more efficiently. This is because the phosphorus compound in the treated water reacts with the iron ions or aluminum ions to be adsorbed to the adsorption member.

In addition, the sewage treatment apparatus according to the present invention includes an electrode which is immersed in the treated water, an electrode support portion for supporting the electrode without being immersed in the treated water, and a connector for connecting the electrode to a power source. It is preferably installed in.

As a result, the electrical connection between the electrode and the power supply can be prevented from being immersed in the treated water.

In addition, in the sewage treatment apparatus according to the present invention, it is preferable that an electrode support portion is formed with a notch portion to which at least a portion of the electrode can be fitted.

As a result, the fixing position of the electrode is stabilized.

Therefore, since the distribution of the ions supplied from the electrode in the ion supply unit is stabilized, the sewage treatment capability in the sewage treatment apparatus is stabilized.

A sewage treatment apparatus according to another aspect of the present invention includes an electrolytic unit having an electrode, and is a sewage treatment apparatus which deposits phosphorus component in treated water as a metal salt that is poorly soluble in water by electrolyzing an electrode in the electrolytic unit. The unit is further characterized by a case covering only the side of the electrode.

According to the present invention, the metal ion generated by electrolysis of the electrode by covering the case with the case can react with the treated water efficiently. In addition, since the case does not have a bottom surface, the metal salt formed by the reaction between the metal ions and the phosphorus component in the treated water can quickly move to a place away from the electrode.

Therefore, in the sewage treatment apparatus, it is possible to avoid a decrease in the efficiency of the electrolysis reaction of the electrode and the reaction of the metal ions and the phosphorus component in the treated water by the precipitated metal salt. That is, the phosphorus compound can be reliably removed from the sewage treatment apparatus.

In addition, the sewage treatment apparatus according to the present invention, it is preferable that the electrolytic unit further comprises a stirring means for stirring the space surrounded by the case.

As a result, the metal ions generated by the electrolysis of the electrode can be reacted with the treated water more efficiently.

In addition, the sewage treatment apparatus according to the present invention further comprises an anaerobic tank in which anaerobic microorganisms are present, an aerobic tank in which aerobic microorganisms are present, and a precipitation tank for depositing sludge, and the electrolytic unit is an anaerobic tank, an aerobic tank, or a precipitation tank. It is preferable to be installed inside.

Thereby, a sewage treatment apparatus can be made more compact.

A sewage treatment apparatus according to another aspect of the present invention includes an electrolytic unit having an electrode, wherein the sewage treatment apparatus is used to electrolyze an electrode in the electrolytic unit to precipitate phosphorus components in the treated water as metal salts which are poorly soluble in water. It characterized in that it further comprises a recovery unit installed adjacent to the electrolytic unit downstream of the electrolytic unit to selectively recover the.

According to the present invention, the metal salt precipitated in the sewage treatment apparatus can be recovered by the recovery unit. For this reason, it can suppress that the said metal salt mixes with sludge in a sewage treatment apparatus.

Therefore, the precipitated metal salt can be prevented from inhibiting the reaction in the vicinity of the electrode, and the efficiency of recovering the metal salt in a renewable state can be improved. That is, the phosphorus compound can be reliably removed from the sewage treatment apparatus, and the recycling efficiency of phosphorus can be improved.

Moreover, it is preferable that the wastewater treatment apparatus concerning this invention is equipped with the adsorption | suction material for catching a metal salt.

Thereby, a metal salt can be collect | recovered in the state which can be reproduced more reliably.

In addition, the sewage treatment apparatus according to the present invention further includes an inflow tank into which the daily wastewater is introduced, and it is preferable to install an electrolytic unit and a recovery unit in the inflow tank.

As a result, the electrolytic unit and the recovery unit are provided in a tank in which metal salts which are poorly soluble in water precipitated by the sewage treatment apparatus are easily mixed with sludge.

Therefore, the phosphorus component can be efficiently supplied to the electrolytic unit, and the effect of the recovery unit can be sufficiently exhibited.

In addition, the sewage treatment apparatus according to the present invention further comprises an anaerobic tank in which anaerobic microorganisms are present, an aerobic tank in which aerobic microorganisms are present, and a settling tank in which sludge is precipitated, and the electrolytic unit and the recovery unit outside the anaerobic tank, aerobic tank and sedimentation tank, In addition, it is preferable to install so that sewage after treatment in an anaerobic tank, an aerobic tank and a sedimentation tank flows in.

Thereby, mixing with sludge can be suppressed as much as the metal salt insoluble in water precipitated by a sewage treatment apparatus.

In addition, the flocculation sedimentation device according to another aspect of the present invention is the first to introduce the sewage from the first article and the first to introduce the sewage after the nitrogen removal treatment with the metal ions, and to aggregate the precipitate resulting from the reaction, A flocculation sedimentation device comprising a second tank for sedimentation of aggregates in a tank, comprising: an electrolytic cell connected to an upstream side of the first tank, having an electrode, and supplying metal ions to the first tank by electrolyzing the electrode; It is characterized by including.

According to the present invention, metal ions are supplied to Article 1 by electrolysis of an electrode without introducing a dangerous chemical agent used as a conventional flocculant. As a result, pH adjustment is unnecessary at the time of aggregation.

Therefore, the phosphorus component in the sewage can be aggregated safely and reliably in the flocculation sedimentation apparatus.

In the flocculation settling apparatus according to the present invention, the electrolyzer is preferably configured such that the waste water stays for at least 3 minutes.

Thereby, an electrolytic cell can be comprised more compactly.

In addition, the flocculation sedimentation apparatus according to another aspect of the present invention is the first to introduce the sewage from the first article and the first to introduce the sewage after the nitrogen removal treatment with the metal ions, and to aggregate the precipitate resulting from the reaction, An agglomeration sedimentation apparatus comprising a second tank for sedimentation of agglomerates in the first tank, wherein the first tank includes an electrode, and the metal ions are supplied to the first tank by electrolysis of the electrode.

According to the present invention, metal ions are supplied to Article 1 by electrolysis of an electrode without introducing a dangerous chemical agent used as a conventional flocculant. As a result, pH adjustment is unnecessary at the time of aggregation.

Therefore, the phosphorus component in the sewage can be aggregated safely and reliably in the flocculation sedimentation apparatus.

In addition, the coagulation settling apparatus according to the present invention, the electrode is electrolyzed by supplying electric power from a predetermined power source, further comprises a wiring for connecting the electrode and the predetermined power supply, and an electrode support member for supporting the electrode, the electrode It is preferable that the supporting member contains at least a part of the wiring.

Thereby, wiring can be arrange | positioned more compactly and hard to be submerged in water.

(Formal door 1)

These and other objects, features, aspects, and advantages of the present invention will become apparent from the following detailed description of the invention, which is understood in conjunction with the accompanying drawings.

Embodiment of the invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing. The sewage treatment apparatus of each embodiment described below is mainly applied to a large-scale wastewater treatment facility for treating domestic wastewater or factory wastewater. Moreover, according to the sewage treatment apparatus of each embodiment, the coagulation sedimentation process of especially the phosphorus compound contained in domestic wastewater, wastewater of a plating factory, etc. can be performed.

[First Embodiment]

With reference to FIG. 1, the tank 1 is buried underground. Inside the tank 1, the first anaerobic filtration tank (5), the second anaerobic filtration tank (10), which will be described later by the first division wall (2), the second division wall (3), and the third division wall (4), It is divided into a contact vent 14, a treatment tank 19 and a disinfection tank 21. The upper portion of the tank 1 is covered with a plurality of manholes 28.

In the first anaerobic filter tank (5), domestic wastewater flows in through the inlet port (6). The first anaerobic filter 7 is installed in the first anaerobic tank 5. In the first anaerobic filter tank (5), the hardly decomposed miscellaneous material mixed in the introduced domestic wastewater is sedimented and the organic matter in the domestic wastewater is anaerobicly decomposed by the anaerobic microorganisms attached to the first anaerobic filter (7). In the first anaerobic filter tank 5, organic nitrogen in domestic wastewater is anaerobicly decomposed into ammonia nitrogen.

The 1st flow pipe 8 is for supplying the treated water anaerobicly decomposed by the said 1st anaerobic filtration tank 5 to the 2nd anaerobic filtration tank 10 through the 1st water supply port 9. The first water inlet 9 penetrates the upper portion of the first dividing wall 2.

The second anaerobic filtration tank 10 is partitioned from the first anaerobic filtration tank 5 by the first dividing wall 2. The second anaerobic filter 11 is installed in the second anaerobic tank 10. Suspended matter is captured in the second anaerobic phase (11). In addition, organic matter is anaerobicly decomposed by the anaerobic microorganisms in the second anaerobic filter (11), resulting in organic nitrogen. Organic nitrogen is anaerobic to ammonia nitrogen.

The second advection pipe 12 is for supplying the treated water anaerobicly decomposed in the second anaerobic filter tank 10 to the contact vent tank 14 through the second water supply port 13. The second water supply port 13 penetrates through the upper portion of the second dividing wall 3. The blowing device 32 is provided with the blowing port 31 in the 2nd air flow pipe 12, and is connected to the 3rd blower 30. As shown in FIG. The blowing device 32 blows out the air from the blowing port 31 into the second flow pipe 12 by sending air from the third blower 30. Thereby, the water supply of the treated water from the 2nd anaerobic filter tank 10 in the 2nd flow pipe 12 to the contact ventilation tank 14 is accelerated | stimulated.

The treated water anaerobicly treated in the second anaerobic filter tank 10 flows into the contact vent tank 14 through the second advection pipe 12. The contact material 15 provided in the contact vent 14 facilitates the cultivation of aerobic microorganisms. The first diffuser 16 is provided near the bottom of the contact vent 14 and has a plurality of air outlets. The first diffuser 16 is connected to the first blower 17, discharges air supplied from the first blower 17 from the air blower outlet, and maintains the inside of the contact ventilator 14 in an exhaled state. As a result, in the contact venting tank 14, the treated water is aerobicly decomposed by the aerobic microorganisms, and at the same time, ammonia nitrogen is decomposed into nitrate nitrogen by the action of nitrifying bacteria. In general, nitrifying bacteria refers to ammonia-oxidizing bacteria and nitrous oxide bacteria.

The contact film 15 has a biofilm that has grown and gradually increased. And when air is supplied from the 1st blower 17 to the 1st diffuser 16, air will be discharged from the air blower outlet of the 1st diffuser 16, and the biofilm attached to the contact material 15 will peel off. do.

The treatment water tank 19 is partitioned from the contact vent tank 14 by the third dividing wall 4. The third flow pipe 29 is connected to the first pump 18, and the supernatant liquid of the treated water aerobicly decomposed in the contact vent 14 by the operation of the first pump 18 passes through the communication port 20. It is supplied to the process tank 19. The communication port 20 has penetrated the upper part of the 3rd partition wall 4.

The supernatant of the treatment tank 19 flows into the disinfection tank 21. A sterilizer 22 is provided inside the sterilization tank 21. The treated water flowing into the disinfection tank 21 is sterilized by a chemical such as chlorine system provided in the sterilizer 22. Then, the sterilized treated water is drained out of the tank 1 through the drain port 23.

The 1st conveyance tube 24 is a tube which communicates the disinfection tank 19 and the electrolytic cell 37. FIG. The 2nd diffuser 25 is provided in the 1st conveyance pipe 24, is formed with many air outlets, and is connected to the 2nd blower 26. As shown in FIG. The second diffuser 25 discharges air supplied from the second blower 26 from the air blower outlet. Thereby, the predetermined amount of supernatant liquid in the processing tank 19 is absorbed in the 1st conveyance pipe 24, and is conveyed to the electrolytic cell 37. FIG.

The electrodes 41 and 42 are provided in the electrolytic cell 37, and the 3rd diffuser 40 is provided below the said electrodes 41 and 42. As shown in FIG. The third diffuser 40 is provided with a plurality of air blowing ports, and is connected to the fourth blower 39. And the air is sent from the 4th blower 39, and the 3rd diffuser 40 blows air from an air blower outlet, and the film | membrane, such as a passivation film | membrane resulting from the biofilm, the nitrate ion, etc. on the surface of the electrodes 41 and 42, is discharged. Remove And it is preferable that the electrodes 41 and 42 are provided in the vicinity of the wall surface of the electrolytic cell 37 so that removal of the film | membrane by the blowing of the air of the 3rd diffuser 40 can be performed more effectively.

The treated water in the electrolytic cell 37 is discharged to the first anaerobic filter tank 5 through the discharge port 47. And the cover 36 is provided in the discharge port 47 of the electrolytic cell 37. The cover 36 is connected to the floating beads 35. In the vicinity of the lid 36, a water level sensor 48 for detecting the water level of the first anaerobic filter 5 is provided. The electrodes 41, 42, the water level sensor 48, and the fourth blower 39 are connected to the power supply device 38.

The electrodes 41 and 42 are made of iron or aluminum, for example. The power supply device 38 applies a voltage to the electrodes 41 and 42 so that one side is a positive pole and the other side is a negative pole. Here, the electrolytic reactions at the + and-poles when the electrodes 41 and 42 are made of iron are shown.

+ ^{Pole: Fe → Fe 2+ + 2e -} ... (One)

^{Polar: 2H + + 2e - → H} 2 ↑ ... (2)

The divalent iron ions (Fe ²⁺ ) produced by the positive electrode are oxidized by air to form trivalent iron ions (Fe ³⁺ ). On the other hand, when the electrodes 41 and 42 are made of aluminum, the reaction of the negative electrode does not change, and the electrolytic reaction of the positive electrode becomes the following formula (3).

+ ^{Pole: Al → Al 3+ + 3e -} ... (3)

In the present embodiment, the case in which the electrodes 41 and 42 are made of iron is described below, but it is possible to change iron to aluminum at all points except for special cases.

Trivalent iron ions (Fe ³⁺ ) produced by the electrolytic and oxidation reactions of formula (1) are used to aggregate the phosphorus compounds in the treated water sent from the first conveying pipe 24. And the main thing of the reaction formula of the phosphorus compound aggregation using Fe3 ⁺ is shown in Formula (4).

PO ₄ ^3- + Fe ³⁺ → FePO ₄ ↓... (4)

At the bottom of the electrolytic cell 37, a valve 43 for removing aggregates or sludge from the electrolytic cell 37 from the electrolytic cell 37 is formed. By opening the valve 43, the sludge aggregate in the electrolytic cell 37 moves to the first anaerobic filter tank 5.

2 is a diagram showing a detailed configuration of the electrolytic cell 37 and its vicinity. The treated water sent from the first conveyance pipe 24 flows into the inlet port 46 of the electrolytic cell 37 with reference to FIG. 2. The third diffuser 40 is provided near the electrodes 41 and 42. The third diffuser 40 supplies air in the vicinity of the electrodes 41 and 42.

The lid 36 covering the outlet 47 is connected to the floating beads 35. And the lid 35 is a hinge 34 and the lower end is connected to the discharge port 47, and covers the discharge port 47 so that opening and closing is possible. Here, when the lid 36 is in the open state with respect to the water level of the first anaerobic tank 5, the solution in the first anaerobic tank 5 flows into the electrolytic cell 37 through the outlet 47. The water level which does not go is made into the water level 100A, and the water level which flows into the electrolyzer 37 through the discharge port 47 is made into the water level 100B.

When the water level of the first anaerobic filter tank 5 is the water level 100A, since the floating beads 35 are in the position indicated by reference numeral 35A in Fig. 2, the lid 36 opens the outlet 47 indicated by reference numeral 36A. It is in a state. On the other hand, when the water level of the first anaerobic filter tank 5 is the water level 100B, the floating beads 35 are in a state in which the discharge port 47 indicated by reference numeral 35B in FIG. 2 is closed. Therefore, in this embodiment, the scum mixed with the discharge port 47 is covered with the cover 36 and the living waste water flowing from the inlet port 6 when the cover 36 is connected to the floating beads 35 is electrolytic cell 37. It can be more reliably avoided to flow directly into). The above-described water level 100A is configured such that a solution in the first anaerobic tank 5 flows into the electrolytic cell 37, and scum and the like in the solution contain a water level that does not flow into the electrolytic cell 37. Can be.

A control unit (not shown) is formed in the electrolytic cell 37, and the control unit includes opening and closing of the valve 43, a current value flowing through the electrodes 41 and 42, a voltage value between the electrodes 41 and 42, and a third diffuser 40 The amount of air blown out from the NELTA), the polarity of the voltage applied to the electrodes 41 and 42 can be controlled.

The water level sensor 48 is provided to detect that the water level of the first anaerobic tank 5 has reached a predetermined water level. The detection output of the water level sensor 48 is input to the controller. Here, the predetermined water level is, for example, the water level at which the household wastewater flowing in from the inlet 6 flows directly into the electrolytic cell 37. When the water level sensor 48 detects that the predetermined water level has been reached, the control unit can issue a warning by voice or display. Since the control part is comprised in this way, since the inflow amount of the waste water through the inflow port 6 can be adjusted so that the daily wastewater which flows in from the inflow port 6 into the electrolytic cell 37 can not be directly flown in, the scum to the electrolytic cell 37 more reliably. This flow can be avoided. The above-mentioned predetermined water level is such that the solution in the first anaerobic filter tank 5 flows into the electrolytic cell 37, and the scum and the like in the solution may be a water level that does not flow into the electrolytic cell 37.

The human who performs maintenance of the sewage treatment system of this embodiment can judge whether the household wastewater which flows in from the inflow port 6 into the electrolyzer 37 may flow in directly by the said warning. Therefore, when the lid 35 and the floating beads 36 are not provided, it is possible to determine whether scum is deposited near the electrodes 41 and 42 with or without a warning, so that the electrolytic cell 37 is cleaned. The necessity of this can be easily determined.

In addition, the control unit may control to increase the supply amount of air from the third diffuser 40 when the water level sensor 48 detects that the predetermined water level has been reached. Even when scum flows in the vicinity of the electrodes 41 and 42 by the control part performing such control, the scum can be discharged out of the electrolytic cell 37 by increasing the amount of air supplied from the third diffuser 40. This can more reliably avoid accumulation of scum in the vicinity of the electrodes 41 and 42.

That is, in the present embodiment described above, at least one combination of the floating beads 35 and the lid 36 or one side of the water level sensor 48 prevents scum from being deposited near the electrodes 41 and 42. You can do it.

The electrodes 41 and 42 are attached to the electrode support parts 41A and 42A, respectively. The electrode support portions 41A and 42A are located on the upper portions of the electrodes 41 and 42 and are supported by the supporting rods 37A and 37B described below so as not to be immersed in the treated water in the electrolytic cell 37. 3, the structures of the electrodes 41 and 42 and the electrode support parts 41A and 42A are shown. 4, the state in which the electrodes 41 and 42 and the electrode support parts 41A and 42A were combined in order to be mounted on the electrolytic cell 37 is shown.

3 and 4, the upper portions of the electrodes 41 and 42 are screwed to the electrode support portions 41A and 42A, respectively. 41 A of electrode support parts are equipped with the spacer 405 in the surface which should be opposed to 42 A of electrode support parts. The electrode support portion 41A and the electrode support portion 42A are combined and fixed to face each other via the spacer 405, as shown in FIG. By appropriately adjusting the width of the spacer 405, the distance between the electrode 41 and the electrode 42 is adjusted.

Here, the structure of the electrode support part 41A, 42A is demonstrated. 5 is a perspective view of the electrode support portion 41A. 41 A of electrode support parts contain the wiring for connecting the power supply device 38 and the electrode 41 to it. One end of the wiring is the connector 410, and the other end is the connector 411. The electrode 41 is electrically connected to the connector 410 by screwing in the electrode support part 41A. In addition, the connector 411 is electrically connected to the power supply device 38. As a result, the electrode 41 is electrically connected to the power supply device 38 by being screwed onto the electrode support portion 41A. Moreover, the electrode support part 42A also has two connectors similarly to the electrode support part 41A, and contains wiring. The electrode 42 is electrically connected to the power supply device 38 by screwing the electrode support 42A.

Since the electrodes 41 and 42 and the electrode support portions 41A and 42A are configured in this manner, in the sewage treatment system of the present embodiment, the wiring connecting the electrodes 41 and 42 and the power supply device 38 crosses the treated water. Can be avoided. Moreover, the connector which is these connection parts can be prevented from being immersed in the process water and corroding.

6 is a perspective view of the electrolytic cell 37. In the upper part of the electrolytic cell 37, two support bars 37A and 37B are provided at predetermined intervals. The lower ends of the left and right sides of the electrode support portions 41A and 42A are disposed on the support rods 37A and 37B, so that they are disposed on the electrolytic cell 37. That is, in this state, the electrodes 41 and 42 are pinched by the supporting rods 37A and 37B, respectively.

In the electrolytic cell 37, it is supported by one electrode support part so that the position shift of the electrodes 41 and 42 may not occur, and a notch part can be further provided. In FIG. 7, the electrode support part which can support the electrodes 41 and 42 and is provided with the notch part is shown.

The electrode support part 450 is provided with the notch part 451 which can fit the upper part of the electrodes 41 and 42 on both front and back, respectively. The upper portions of the electrodes 41 and 42 are fitted to the notches 451, respectively, and screwed thereto. Thereby, since the position of the electrodes 41 and 42 in the electrolytic cell 37 is fixed more reliably, distribution of iron ion in the electrolytic cell 37 is stabilized. Therefore, in the electrolytic cell 37, the reaction of Formula (4) occurs stably. Thereby, the sewage treatment capability of the sewage treatment apparatus of this embodiment is stabilized. And when the electrode support part 450 is provided on the electrolytic cell 37, the lower surface of the right end 450A and the left end 450B contact the support rods 37A and 37B. Thereby, the electrodes 41 and 42 are pinched by the support bars 37A and 37B in the state provided in the electrolytic cell 37, respectively.

When the electrode support part 450 and the electrodes 41 and 42 are unitized and transported, it is preferable to be accommodated in a case and transported, as shown in FIG. In detail, the unitized electrode support portion 450 and the electrodes 41 and 42 are housed in the case 460 so that the portions of the electrodes 41 and 42 enter the case 460. And when accommodated, the right end 450A and the left end 450B of the electrode support part 450 are screwed to the case 460 by the screws 461 and 462, respectively.

Second Embodiment

Next, a second embodiment of the present invention will be described. The sewage treatment apparatuses of the sixth embodiment from the second embodiment are designed to remove phosphorus compounds in the sewage, and can also be used as a single body. The anaerobic microorganisms, such as anaerobic filtration, It can also be used in combination with the treatment tank to accommodate.

Referring to Fig. 9, the activated sludge tank 61 accommodates the activated sludge and is configured to send wastewater from another apparatus or the like through the inlet port 69. The first diffuser 62 is provided at the bottom of the activated sludge tank 61. The first diffuser 62 is connected to the first blower 65 and discharges air supplied from the first blower 65 from the air blower outlet. As a result, the inside of the activated sludge tank 61 is kept in aerobic state, and the treated water is aerobicly decomposed by aerobic microorganisms, and the ammonia nitrogen is decomposed into nitrate nitrogen by the action of nitriding.

One end of the circulation pipe 63 is inserted into the activated sludge tank 61. The treated water in the activated sludge tank 61 is sent to the electrolytic cell 70 through the circulation pipe 63 by the pump 64. In addition, the symbol of the treated water in the activated sludge tank 61 is sent to the settling tank 67 through the advection pipe 77.

The electrolytic cell 70 is equipped with the electrodes 71 and 72, These can be comprised by iron or aluminum. The electrodes 71 and 72 are connected to the power supply 73 via the wiring 73A, and are supplied with iron ions or aluminum ions to the electrolytic cell 70 by being electrolyzed. And by supplying such metal ions, in the electrolytic cell 70, a phosphorus compound aggregates according to Formula (4) mentioned above, for example. The second diffuser 74 is provided below the electrodes 71 and 72 of the electrolytic cell 70. The second diffuser 74 is connected to the second blower 66 and discharges the air supplied from the second blower 66 to the electrodes 71 and 72 from the air blower outlet. A valve 75 is provided below the second diffuser 74. The valve 75 is provided to be openable and close, and is normally closed. However, the valve 75 is appropriately opened to discharge the sludge and aggregates in the electrolytic cell 70 to the active sludge tank 61.

The activated sludge tank 61 is provided with a magnet 61A. And the aggregate of the phosphorus compound produced in the electrolyzer 70 adsorb | sucks to the magnet 61A. Thereby, in the sewage treatment apparatus in this embodiment, the phosphorus compound in treated water can be removed more reliably. The aggregate of the phosphorus compound is considered to adsorb to the magnet 61A in an oxidized form. In this embodiment, the magnet 61A constitutes a suction means made of a magnetic member.

The electrodes 71 and 72 are supported by the electrode support parts 71A and 72A whose upper part has the same shape as the electrode support parts 41A and 42A similarly to the electrodes 41 and 42 mentioned above.

The electrode support portions 71A and 72A also have two connectors similarly to the electrode support portions 41A and 41B, and each contain a wiring 73A.

Similarly to the electrode support portion 450, the electrode support portions 71A and 72A are also provided with notches that can fit the upper portions of the electrodes 71 and 72, respectively.

In addition, the activated sludge is sent to the electrolytic cell 70 of this embodiment from the activated sludge tank 61 with the treated water. The reaction product according to the above formula (4) aggregates relatively easily around the activated sludge from the activated sludge tank 61, and the individual aggregates become larger. Therefore, since the reaction product according to the above formula (4) easily precipitates as agglomerates, the electrolytic reaction of the electrodes 71 and 72 occurs relatively quickly even when the treatment period in the electrolytic cell 70 reaches a long time. The distance between the electrodes 71 and 72 is preferably 2 cm or more in consideration of the size of the sludge.

On the other hand, in the settling tank 67, the symbol of the treated water sent is discharged through the discharge port 78. On the other hand, sludge 68 is deposited at the bottom of the settling tank 67. The sludge 68 of the settling tank 67 is regularly removed.

According to the sewage treatment apparatus of this embodiment, since the magnet 61A is provided, the removal rate of a high phosphorus compound of about 90 to 95% can be achieved, depending on the scale of the apparatus.

[Third Embodiment]

Next, a third embodiment of the present invention will be described.

Referring to Fig. 10, the active sludge tank 81 accommodates the activated sludge and is configured to send wastewater from another apparatus or the like through the inlet port 89. At the bottom of the activated sludge tank 81, a first diffuser 82 is provided. The first diffuser 82 is connected to the first blower 85 and discharges air supplied from the first blower 85 from the air blower outlet.

One end of the circulation pipe 83 is inserted into the active sludge tank 81, and the treated water in the active sludge tank 81 is sent to the electrolytic cell 90 through the circulation pipe 83 by the pump 84. In the activated sludge tank 81, an advection tube 98 having a membrane 97 at its distal end is provided so that a portion of the membrane 97 is immersed in the active sludge tank 81. The treated water in the activated sludge tank 81 is discharged out of the active sludge tank 81 through the membrane 97 and through the inside of the flow pipe 98 by the pump 87. As the membrane 97, for example, a flat membrane or a hollow fiber membrane having a pore diameter of about 0.05 to 1 m can be used.

The electrolytic cell 90 is equipped with the electrodes 91 and 92, These can be comprised by iron or aluminum. The electrodes 91 and 92 are connected to the power supply device 93, and iron or aluminum ions are supplied to the electrolytic cell 90 by these electrolysis. A second diffuser 94 is provided below the electrodes 91 and 92 of the electrolytic cell 90. The second diffuser 94 is connected to the second blower 86, and the second blower 86 is provided. Air supplied from the air is discharged from the air outlet to the electrodes 91 and 92 in the vicinity. A valve 95 is provided below the second diffuser 94. The valve 95 is provided to be openable and close, and is normally closed. However, the valve 95 is appropriately opened to discharge the sludge and aggregates in the electrolytic cell 90 to the active sludge tank 81. Sludge is deposited at the bottom of the active sludge 81, which is periodically removed.

The electrodes 91 and 92 are supported by the electrode support part (not shown) which the upper part has the same shape as the electrode support parts 41A and 42A similarly to the electrode 41 and 42 mentioned above.

And the film 97 is attached to the magnet 97A. Here, the structures of the film 97 and the magnet 97A will be described in detail. 11 is a side view of the membrane 97 and the magnet 97A.

Referring to Figs. 10 and 11, the magnet 97A has a donut shape. And the film 97 is attached so that the hole of the center of the magnet 97A may be covered from both front and back. 12 is a partial perspective view of magnet 97A. An opening is formed in an upper portion of the magnet 97A, and one end of the advection tube 98 is connected to the opening. That is, in the sewage treatment apparatus of the present embodiment, the treated water reaching up to the vicinity of the magnet 97A is guided into the airflow tube 98 via the membrane 97.

In this embodiment, since the magnet 97A is formed in the vicinity of the film 97, the aggregate of the phosphorous compound is prevented from adsorbing to the magnet 97A and reaches the film 97, so that the blockage of the film 97 can be suppressed. Can be.

This embodiment is considered to have changed the settling tank 67 in the 2nd embodiment to the membrane 97. Thereby, a sewage treatment apparatus can be made more compact.

In the present embodiment, the removal rate of the high phosphorus compound of 90% or more can be achieved by providing the magnet 97A and filtering the treated water by the membrane 97.

In this embodiment described above, the magnet 97A constitutes a suction means made of a magnetic member. In addition, the membrane 97 constitutes a filter for filtering the treated water in the activated sludge tank. In this embodiment, the magnet 97A and the film 97 are integrally formed, but the present invention is not necessarily limited to such a configuration. It is preferable that they are formed integrally, but they are not necessarily formed integrally as long as they are formed near each other.

Fourth Embodiment

Next, a fourth embodiment of the present invention will be described.

Referring to FIG. 13, the active sludge tank 101 is divided into a portion accommodating the active sludge and a portion not accommodating by the separator plate 107. In addition, since the lower side of the separator plate 107 is not connected to the active sludge tank 101, there is a gap, so that the treated water and the sludge can be moved. In addition, the activated sludge tank 101 is configured to send wastewater from another device or the like through the inlet 109. At the bottom of the activated sludge tank 101, a first diffuser 102 is provided. The first diffuser 102 is connected to the first blower 105 and discharges air supplied from the first blower 105 from the air blower outlet.

One end of the circulation pipe 103 is inserted into the activated sludge tank 101. The treated water in the activated sludge tank 101 is sent to the electrolytic cell 110 through the circulation pipe 103 by the pump 104. In addition, the symbol of the treated water in the active sludge tank 101 is discharged out of the active sludge tank 101 through the discharge port 118.

The electrolytic cell 110 is equipped with the electrodes 111 and 112, These can be comprised by iron or aluminum. The electrodes 111 and 112 are connected to the power supply device 113, and iron or aluminum ions are supplied to the electrolytic cell 110 by these electrolysis. The second diffuser 114 is provided below the electrodes 111 and 112 of the electrolytic cell 110. The second diffuser 114 is connected to the second blower 106 and discharges the air supplied from the second blower 106 to the electrodes 111 and 112 from the air blower outlet. The valve 115 is provided below the second diffuser 114. The valve 115 is provided to be openable and close, and is normally closed, but is suitably opened to discharge the sludge or aggregates in the electrolytic cell 110 to the active sludge tank 101.

A magnet 107A is attached to the side of the separator plate 107 on which the active sludge is not received. The aggregate of the phosphorus compound in the aggregate in the electrolytic cell 110 can be efficiently collected by the magnet 107A.

As in this embodiment, by adsorbing and collecting agglomerates of phosphorus compounds on the magnet 107A, the phosphorus compounds in the treated water can be collected in an easily reproducible form. As a result, phosphorus depletion is a serious situation today. In the present invention, it can be said that the sewage treatment apparatus of the present embodiment can contribute to high efficiency of phosphorus regeneration.

The sewage treatment apparatus of the present embodiment described above has a configuration in which a sedimentation tank 67 is provided in the active sludge tank 61 of the sewage treatment apparatus shown in FIG. 9 by providing the separator plate 107.

In addition, according to the sewage treatment apparatus of this embodiment, although the removal rate of a high phosphorus compound of about 90 to 95% can be achieved, depending on the scale of the apparatus.

[Fifth Embodiment]

Next, a fifth embodiment of the present invention will be described.

With reference to FIG. 14, the overall structure of the sewage treatment apparatus in this embodiment is almost the same as that of the sewage treatment apparatus shown in FIG. 9, and the same reference numerals are given to the same components as those in the sewage treatment apparatus shown in FIG. The description is not repeated.

In the sewage treatment apparatus of the present embodiment, the treated water in the activated sludge tank 61 is sent to the electrolytic cell 70 through the circulation pipe 63 by the pump 64. The symbol of the electrolytic cell 70 is sent to the settling tank 67 via the outflow pipe 76. Then, the symbol of the settling tank 67 is discharged out of the wastewater treatment apparatus from the discharge port 78.

A magnet 67A is provided in the outflow pipe 76 in the settling tank 67. Thereby, the aggregate of the phosphorus compound produced in the electrolytic cell 70 can be adsorbed to the magnet 67A more efficiently and in the form separated from another aggregate and sludge. Therefore, it is considered that the sewage treatment apparatus of the present embodiment can contribute to higher efficiency of phosphorus regeneration than the fourth embodiment.

[Sixth Embodiment]

Next, a sixth embodiment of the present invention will be described.

With reference to FIG. 15, the overall structure of the sewage treatment apparatus in this embodiment is almost the same as that of the sewage treatment apparatus shown in FIG. 13, and the same reference numerals are given to the same components as those of the sewage treatment apparatus shown in FIG. The description is not repeated.

In the sewage treatment apparatus of the present embodiment, the active sludge tank 101 is a region accommodating active sludge from the inlet port 109 in order by the separator plates 107, 150, a region accommodating the electrodes 111, 112, and a sludge. 108 is divided into regions for precipitating.

The treated water sent from the inlet 109 is accommodated in the area for receiving sludge in the active sludge 101, and the symbol of the area is sent to the area for receiving the electrodes 111, 112.

The treated water and agglomerates below the area accommodating the electrodes 111, 112 are sent to the area for sedimentation of the sludge 108, with the symbol of the area being discharged out of the active sludge 101 through the outlet 118. do.

And the magnet 150A is provided in the wall surface of the area | region side in which the sludge 108 of the separator plate 150 is settled. Thereby, the aggregate of the phosphorus compound produced | generated in the area | region which accommodates the electrodes 111 and 112 can be made to adsorb | suck to the magnet 150A more efficiently, in the form separated from another aggregate or sludge.

The treated water discharged out of the activated sludge tank 101 is preferably sent to an anaerobic filter tank (a tank containing anaerobic microorganisms) separately installed.

In the active sludge 101, the sidewalls that include the areas for depositing the sludge 108 are angled to make it easier to direct the sludge 108 to the area that receives the sludge.

[Seventh Embodiment]

The sewage treatment apparatus of this embodiment is a sewage treatment apparatus of the type which can integrate a manhole and an electrode. Since the sewage treatment apparatus of this embodiment shown in FIG. 16 changes only the structure of the peripheral part of the manhole 28 and the electrodes 41 and 42 from the sewage treatment apparatus shown in FIG. 1, it is similar to the sewage treatment apparatus shown in FIG. The same reference numerals are given to the components, and the description is not repeated.

Referring to FIG. 16, the upper part of the sewage treatment apparatus is covered with a plurality of manholes 28. The manholes 28 are provided with electrodes 41 and 42 via an insulator 400. Here, with reference to FIG. 17, the mounting aspect of the electrodes 41 and 42 to the insulator 400 is demonstrated.

In the sewage treatment apparatus of this embodiment, the electrodes 41 and 42 are attached to the manhole 28 via the insulator 400. In detail, the electrodes 41 and 42 are mounted to the insulator 400 by screwing or the like. The insulator 400 on which the electrodes 41 and 42 are mounted is attached to the manhole 28 by screwing or the like. The connecting lines 402 are connected to the electrodes 41 and 42, respectively, and are connected to the power supply device 38. Thereby, the worker can take out electrodes 41 and 42 to the ground, without entering into the basement by operating the handle 28A of the manhole 28 from the ground, and removing the manhole 28. As shown in FIG. That is, the maintenance of the electrodes 41 and 42 becomes remarkably easy compared with the wastewater treatment apparatus of other embodiment.

In the sewage treatment apparatus of the present embodiment, the electrodes 41 and 42 are immersed in the treated water, but the insulator 400 is configured not to be immersed in the treated water. In addition, a connecting line having connectors at both ends may be accommodated in the insulator 400, and one end connector may be connected to the power supply device 38, and the other end connector may be connected to the electrode 41 or the electrode 42. In this way, the connection between the electrodes 41 and 42 and the power supply device 38 can be avoided from being submerged in the treated water. That is, it can avoid that the said connection part corrodes.

And when the electrodes 41 and 42 are attached to the manhole 28 like this embodiment, when the position of the electrodes 41 and 42 in a sewage treatment apparatus becomes high compared with the position of the electrode in other embodiment. There is. When the positions of the electrodes 41 and 42 are increased, the electrodes 41 and 42 are not submerged in the treated water, and iron or aluminum ions are not supplied even when a voltage is applied to the electrodes 41 and 42. Therefore, in the present embodiment, it is possible to determine whether the electrodes 41 and 42 are immersed in the treated water by monitoring the voltage values between the electrodes 41 and 42 by the detecting unit 38A. In the sewage treatment apparatus of the present embodiment, when the voltage value between the electrodes 41 and 42 indicates that the electrodes 41 and 42 are not immersed in the treated water, it is preferable that the sewage treatment apparatus is provided with means for notifying the sewage treatment apparatus. .

[Eighth Embodiment]

In the sewage treatment system shown in FIG. 18, the same components as those in the sewage treatment system (see FIG. 1) described in the first embodiment are denoted by the same reference numerals and overlapping descriptions will not be repeated. 19, a part of the member shown in FIG. 18 is omitted.

The sewage treatment system of this embodiment with reference to FIG. 18 and FIG. 19 mainly consists of the tank 200. As shown in FIG. The inside of the tank 200 is first anaerobic filtration tank 5, the second by the first partition wall 2, the second partition wall 3, the third partition wall 4, and the fourth partition wall 20. It is divided into an anaerobic filter tank (10), a contact vent tank (14), a settling tank (19), and a disinfection tank (21). And in the tank 200 of this embodiment, the lower end of the 3rd division wall 4 is used instead of the 3rd airflow pipe 29 and the 1st pump 18 in the tank 1 shown in FIG. It is spaced apart from the bottom of the tank 200. As a result, in the tank 200, the treated water that is aerobicly decomposed in the contact vent 14 is supplied to the treated water tank 19.

The upper end of the first diffuser 16 is connected to the first blower 17. And the lower end of the 1st diffuser 16 is provided so that the inner periphery may be rounded slightly rather than the outer periphery of the bottom face of the contact vent 14 (refer FIG. 19). A plurality of holes (holes 16A: see FIG. 19) are formed on the lower surface side of the first diffuser 16. And when air is sent from the 1st blower 17, this air is discharged | emitted as a bubble from the said hole. Moreover, when a hole is formed in the lower surface side of the 1st diffuser 16, a sludge is less likely to enter inside than when the hole is formed in an upper surface or a side surface.

The lower part of the contact vent 14 is provided with a pump 133. Moreover, the sludge conveyance path 134 is connected to the upper side of the pump 133, and the sludge conveyance path 135 is connected to the upper end of the sludge conveyance path 134 so that it may extend to the left side of the figure. Thereby, the sludge which arose from the contact ventilation tank 14 is sent to the 1st anaerobic filter tank 5.

In the tank 200 of FIG. 18, the settling tank 19 and the 1st anaerobic filter tank 5 are connected through the 1st conveyance pipe 24. As shown in FIG. The 1st conveyance pipe 24 is equipped with the 2nd diffuser 25 inside. The 2nd diffuser 25 is connected to the 2nd blower 26, and the blowing hole for blowing air is formed. Then, the second diffuser 25 blows the air supplied from the second blower 26 from the blowing hole, and passes the treated water in the settling tank 19 through the first conveying pipe 24 to the first anaerobic filter tank 5. To send).

In addition, an electrolytic unit including a case 54 is provided at the upper portion of the contact vent 14. Specifically, the case 54 is a hollow body to which four vertical plates are connected. Electrode pairs 51 and 52 are provided inside the case 54. The electrode pairs 51 and 52 are connected to the power supply 57, respectively. In addition, a third diffuser 53 is provided inside the case 54. The third diffuser 53 is connected to the fourth blower 56.

In the case 54, metal ions such as iron ions and aluminum ions are eluted by the electrolysis (referred to as appropriate electrolysis) reaction in the electrode pairs 51 and 52. As a result, in the contact venting tank 14, the eluted metal ions react with the phosphorus compound in the treated water to form and aggregate a metal salt which is poorly soluble in water. Formula (4) mentioned above is mentioned as an example of reaction of a metal ion and a phosphorus compound.

Next, the structure of the electrolytic unit of this embodiment is demonstrated, referring FIG. 20 and FIG. 20 is a perspective view of an electrolytic unit. 21 is an exploded perspective view of the electrolytic unit.

The case 54 is provided with mounting members 541, 542, 543, and 544 in four places of the upper end. In addition, the case 54 is divided into two spaces whose insides are arranged to the left and right by the separating plate 540. In addition, the third diffuser 53 is introduced into the case 54 from the upper side to the lower side. The third diffuser 53 has a portion extending from the right side to the left side of the lower portion of the case 54.

The electrode pairs 51 and 52 are provided with two electrodes 511, 512, 521, and 522 which face each other. In the electrode pairs 51 and 52, the two opposite electrodes are attached to the electrode supports 510 and 520. In each of the electrode pairs 51 and 52, an electrode is connected to the power source 57 (see FIG. 18) through the connectors 513 and 523.

Both ends of the electrode support 510, 520 are mounted to the mounting members 541, 542, 543, 544, respectively, so that the electrodes 511, 512 are on the right side of the separator plate 540, and the electrodes 521, 522 are separator plates. 540 are respectively provided on the left side. An electrolytic reaction occurs between the electrode 511 and the electrode 512 on the right side of the separator plate 540, and an electrolytic reaction occurs between the electrode 521 and the electrode 522 on the left side of the separator plate 540.

And the 3rd diffuser 53 discharge | releases a bubble, and this bubble collides with the inner wall of the case 54, and convection arises in the case 54. As shown in FIG. As a result, the treated water is efficiently supplied to the vicinity of the electrodes 511, 512, 521, and 522. In this embodiment, the stirring means for stirring the space enclosed by the case by the 3rd diffuser 53 is comprised. Incidentally, the stirring means is not limited to a device for emitting bubbles like the third diffuser 53, and may be a device for mixing water in the case 54 such as a stirrer.

In addition, the metal ion eluted by the electrolytic reaction reacts with the phosphorus compound in the treated water to become a metal salt that is poorly soluble in water. On the other hand, the case 54 is a hollow body as mentioned above. That is, the case 54 has a shape without a bottom. Therefore, the metal salt produced here is quickly guided to the contact vent tank 14 by its own weight.

In this embodiment described above, the electrolytic unit is provided in the contact ventilator 14. The electrolytic unit may be installed in another tank in the tank 200 such as the first anaerobic filter tank 5, the second anaerobic filter tank 10, or the settling tank 19. In this embodiment, the precipitation tank which precipitates sludge by the precipitation tank 19 is comprised. In addition, the electrolytic unit may be provided to be adjacent to the inlet 6 or the drain 23 in addition to the tank 200.

And the circulation flow volume of the tank 200 is 3Q. In addition, Q is the amount of water flowing into the tank 200. That is, in the tank 200, three times the amount of water flowing in is circulated.

In addition, the electrolytic reaction in the electrode pairs 51 and 52 is performed so that the concentration of the iron ions or aluminum ions eluted is 1 to 3 times the molar concentration of phosphorus in the treated water. The electrolytic reaction is controlled such that the concentration of iron ions or aluminum ions is preferably about 1-2 times the molar concentration of phosphorus in the treated water, more preferably about 1.5 times. For this reason, in the electrolytic reaction, the current density at the electrode is controlled to be 0.1 mA / cm 2 or more, and in most cases, controlled to be about 0.3 mA / cm 2.

In this way, by controlling the current density at the electrode, it is thought that the formation of an oxide film or organic deposit on the electrode surface can be prevented and these can be removed. It is because it is thought that iron hydroxide and organic deposit which are considered to generate | occur | produce with the electrode of an anode side can be removed by the hydrogen gas which generate | occur | produces at the cathode side, and the ventilation by the 3rd acid engine 53. Therefore, when the current density in the electrolytic reaction is too low, it is considered that the amount of hydrogen gas generated on the cathode side is low so that the deposit on the anode side cannot be sufficiently removed. And the airflow amount of the 3rd diffuser 53 in an electrolytic unit becomes about 15 L / min.

For example, when the amount of domestic wastewater flowing into the tank 200 in one day is set to 1200L, and the circulation flow rate in each tank in the tank 200 is set to 6000L, the electrodes 511 and 512 and the electrodes 521, The current flowing through 522 is controlled at about 650 mA. The current density at each electrode can be controlled by changing the immersion area of each electrode. In addition, with respect to the electrode 511, the electrode 512, and the electrode 521 and the electrode 522, the space | interval becomes about 25 mm, and the voltage between electrodes is always monitored. In addition, the polarity of each electrode is preferably inverted every predetermined time (for example, 24 hours).

[Ninth Embodiment]

The sewage treatment system shown in FIG. 22 changes the arrangement | positioning of an electrolytic unit from the sewage treatment system shown in FIG. 18, and adds several components. Therefore, in Fig. 22, the same components as in Fig. 18 are denoted by the same reference numerals and overlapping descriptions will not be repeated.

Referring to Fig. 22, an electrolytic unit including electrode pairs 51 and 52 is provided on the upper side of the first anaerobic filter.

In addition, the sedimentation tank 19 is equipped with the 3rd air flow pipe 38 and the pump 39. The treated water in the contact vent 14 flows into the settling tank 19 through the third flow pipe 38. And this flow is accelerated by the pump 39.

The electrode pairs 51 and 52 are arranged in the electrolytic cell 59. The electrolytic cell 59 is connected to the 1st conveyance pipe 24. As a result, the treated water in the settling tank 19 is guided to the electrolytic cell 59 through the first conveying pipe 24.

The electrolytic cell 59 is equipped with the discharge pipe 592 in the upper left part. The symbol of the treated water guided to the electrolyzer 59 flows into the first anaerobic filter tank 5 through the discharge pipe 592.

Moreover, the electrolytic cell 59 is equipped with the discharge port 591 at the bottom. In the first anaerobic filter tank 5, a phosphorus recovery unit 160 is provided below the electrolyzer 59 so as to be adjacent to the electrolyzer 59.

In the electrolytic cell 59, as described in the eighth embodiment, metal ions are generated by the electrolytic reaction in the electrode pairs 51 and 52, and the metal ions react with the treated water to become poorly soluble metal salts. This poorly soluble metal salt is guided to the phosphorus recovery unit 160 through the outlet 591 by its own weight. That is, the poorly soluble metal salt can be selectively recovered by using the phosphorus recovery unit 160.

23 is a sectional view of the phosphorus recovery unit 160. The phosphorus recovery unit 160 includes a main body 164, a network 162 and 163, an airflow tube 161, and an adsorbent 165. The adsorbent 165 is disposed between the net 162 and the net 163 in order to adsorb fine particles in the above poorly soluble metal salt, and is composed of activated carbon or ceramic. The treated water and the metal salt in the electrolytic cell 59 are guided to the main body 164 via the networks 162 and 163. The symbol of the main body 164 is the outside of the main body 164 via the advection pipe 161 and is discharged in the first anaerobic filtration tank 5.

In the present embodiment described above, the phosphorus recovery unit 160 is provided so as to be adjacent to the downstream side of the electrolytic unit. As a result, the poorly soluble metal salt generated in the electrolytic cell 59 collects at the bottom of the main body 164 of the phosphorus recovery unit 160 or is adsorbed by the adsorbent 165. That is, in the sewage treatment system of the present embodiment, it is possible to recover poorly soluble metal salts from mixing with sludge. And since the adsorbent 165 can be collect | recovered even a fine metal salt, the recovery efficiency of a metal salt can be improved.

In this embodiment, the electrolytic unit and the phosphorus recovery unit 160 are provided in the first anaerobic filter tank 5. The electrolytic unit may be installed in another tank in the tank 1, such as the second anaerobic filter tank 10, the contact vent tank 14, or the settling tank 19. In addition, the electrolytic unit may be provided to be adjacent to the inlet 6 or the drain 23 in addition to the tank 200. However, in this embodiment, when the electrolytic unit and the phosphorus recovery unit 160 are installed in the first anaerobic filter tank 5 which is also a contaminant removal tank, the effect of the phosphorus recovery unit 160 is more remarkably. Can exert. This is because it is considered that the case where the electrolytic unit is installed in the first anaerobic filter tank 5 without the phosphorus recovery unit 160 is more difficult to recover a poorly soluble metal salt in a single unit than when the electrolytic unit is installed in another tank under the same conditions.

[Tenth Embodiment]

First, with reference to FIG. 24A, the daily general wastewater is first introduced into the sedimentation separation tank 601. FIG. In the sedimentation tank 601, anaerobic decomposition of sewage is mainly performed.

Sewage in the sedimentation tank 601 is introduced into the rotor plate contact tank 602. In the rotating plate contacting tank 602, aerobic decomposition of wastewater is mainly performed. In the rotating plate contacting tank 602, an aerobic filter used for propagation of aerobic bacteria is rotated.

Sewage in the rotor plate contact tank 602 is introduced into the settling tank 603. The settling tank 603 is provided for separating sludge from the sewage from the liquid. And the sludge which settled in the settling tank 603 is conveyed to the settling separation tank 601 by well-known means.

Sewage in the settling tank 603 is introduced into the intermediate flow rate adjusting tank 604. The intermediate flow rate adjustment tank 604 is provided for adjusting the flow rate of the filthy water introduced into the electrolytic cell 605 described later.

Sewage in the intermediate flow adjustment tank 604 is introduced into the electrolytic cell 605. The electrolytic cell 605 is a tank for generating metal ions for reacting with a predetermined component in the sewage by electrolysis of the electrode. The detailed structure of the electrolytic cell 605 will be described later.

Sewage in the electrolytic cell 605 is introduced into the coagulation tank 606. The agglomeration tank 606 is mainly provided for reacting the metal ions generated in the electrolytic cell 605 with a predetermined component in the sewage to form a floc. In other words, the metal ions and the predetermined components in the sewage react in the flocculation tank 606. For example, when iron ions are eluted by the electrolytic reaction, it is considered that the reaction according to the above formula (4) occurs.

Moreover, in the flocculation tank 606, the floc of the particle | grains (so-called "SS") which are suspended in the presence of metal ions, and is not dissolved in water is also formed. In the flocculation tank 606, it is preferable to stir suitably for prog formation.

Sewage in the flocculation tank 606 is introduced into the flocculation sedimentation tank 607 together with the procs resulting from the reaction. The flocculation settling tank 607 is provided in order to settle the floc which arose in the flocculation tank 606.

Sewage in the coagulation sedimentation tank 607 is introduced into the disinfection tank 608. The disinfection tank 608 is equipped with chemicals such as chlorine. A disinfection tank 608 is provided for disinfecting the sewage by the chemicals. The sewage in the disinfection tank 608 is discharged to a river or the like. Phosphorus exists as phosphoric acid or organic phosphorus in the sewage, but the sewage discharged from the disinfection tank 608 has a total phosphorus concentration of 1 mg / L.

In the treatment shown in FIG. 24B, a flocculation tank 615 is provided in place of the electrolytic cell 605 and the flocculation tank 606 shown in FIG. 24A, and the metal ions are generated in the flocculation tank 615. A predetermined component of is reacted to form a prok.

In addition, in FIG. 24A and FIG. 24B, the sedimentation separation tank 601, the rotating plate contacting tank 602, and the sedimentation tank 603 are enclosed with the broken line R. In FIG. The processing performed within the range surrounded by the broken line R may be changed as shown in FIG. 25.

25, the sewage in the sedimentation separation tank 601 is introduced into the contact vent tank 620. In the contact ventilation tank 620, aerobic decomposition of wastewater is mainly performed by aerobic bacteria. Incidentally, in the contact vent tank 620, unlike the rotating plate contact tank 602 (see Figs. 24A and 24B), the exhalation filter does not rotate.

Sewage in the contact vent tank 620 is introduced into the settling tank 603. In the contact venting tank 620, the sludge biofilm adhered to the aerobic filter and peeled off by aeration is conveyed to the precipitation separating tank 601 and the precipitation tank 603 by known means.

The tenth embodiment of the present invention is shown below as an apparatus for performing the process according to the flowchart shown in FIG. 24A. Incidentally, an apparatus for performing the processing according to the flowchart shown in Fig. 24B will be described later as an eleventh embodiment of the present invention.

The flocculation settling device of the present embodiment includes at least an electrolytic cell 605, a flocculation tank 606, and a flocculation settlement tank 607 shown in FIG. 24A.

Fig. 26 is a view showing the appearance of a part of the merger and purification tank including the flocculation settling device of the present embodiment. Sewage water is introduced into the intermediate flow rate adjustment tank 604 through a pipe 611 from a predetermined water tank. In addition, sewage is introduced into the electrolytic cell 605 from the intermediate flow rate adjustment tank 604 via a pipe 612. In addition, sewage is introduced into the coagulation tank 606 from the electrolytic cell 605 via a pipe 613. In addition, although illustration is abbreviate | omitted, wastewater is introduce | transduced into the flocculation settling tank 607 from the flocculation tank 606 through a predetermined piping. In the coagulation sedimentation apparatus, the residence time of wastewater in each tank is adjusted by adjusting the capacity of each tank, for example.

FIG. 27 is an exploded perspective view of the electrolytic cell 605 of FIG. 26. The electrolytic cell 605 is mainly composed of a case 650, an electrode fixing plate 653, a plurality of electrode pairs 651, and a lid 652.

The case 650 is supported by the case support 600. In addition, the case 650 is provided with a wastewater inflow hole 650A and a wastewater outflow hole 650B on its side surfaces. In the case 650, wastewater flows in from the wastewater inflow hole 650A, and wastewater flows out from the wastewater flowoff hole 650B.

An diffuser 654 is provided inside the case 650. The diffuser 654 introduces air from a predetermined pump external to the case 650. In addition, a small hole is formed in the diffuser 654 as appropriate. As a result, the diffuser 654 can discharge bubbles into the case 650.

The electrode fixing plate 653 and the electrode pair 651 are housed in the case 650. The electrode pair 651 includes a support 710, respectively, on which two plate-shaped electrodes 711, 712 are mounted. In the electrode fixing plate 653, holes 731 to 736 for fitting the electrodes 711 and 712 are formed. In the case 650, the electrodes 711 and 712 are fitted into the holes 731 to 736 so that the support 710 of each electrode pair 651 is in contact with the upper surface of the electrode fixing plate 653. Each electrode pair 651 is provided with the connector 719C for connecting the external power supply of the electrolytic cell 605, and electrodes 711,712.

The cover 652 is covered on the upper surface of the case 650 in which the electrode pair 651 and the electrode fixing plate 653 are accommodated.

One of the electrodes 711, 712 is made of a metal such as iron or aluminum. The electrolytic cell 605 can supply metal ions, such as iron ions or aluminum ions, into the sewage by any electrolysis of the electrodes 711 and 712 in the electrode pairs 651. have. When the electrode pair 651 is housed in the case 650, deposits on the surfaces of the electrodes 711 and 712 are removed by bubbles released from the small holes of the diffuser 654.

Here, the structure of the electrode pair 651 will be described in detail with reference to FIGS. 28 and 29. 28 is a perspective view of the electrode pair 651. 29 is a perspective view when the electrode pair 651 is partially broken.

The electrode pair 651 includes two metal plates of the electrodes 711 and 712. This metal plate consists of iron and aluminum, for example. In addition, the electrode pair 651 includes a support 710. The handle 710A is mounted on the upper portion of the support 710. The cover 713 is attached to the left side of the support 710. In detail, six screw holes are formed in the cover 713, and the cover 713 is mounted on the left side of the support 710 by screwing each screw hole with a predetermined screw. The cover 713 is equipped with electrodes 711 by nuts 711A and 711B. The screw holes include screw holes 713A, 713B (see FIG. 30), 713C, 713D, and 713E. In addition, the predetermined screws include the screws 717A, 717B, 717C, and 717D shown in FIG.

The guide 719D is attached to the upper rear side of the support 710, and the wiring 719 protrudes from the guide 719D toward the upper side of the support 710. The guide 719D is cylindrical in shape, and the wiring 719 is through the inside of the guide 719D. The connector 719C is connected to one end of the wiring 719.

The support 710 and the cover 713 are incorporated in a combination from the portion in front of the guide 719D of the wiring 719 to the other end thereof. The wiring 719 includes a plurality of wirings (including the wiring 719A to be described later). The other end of the wiring 719 is in a state in which terminals such as the terminal 718 (see FIG. 30) described later are attached to each of the plurality of nested wirings.

30 and 31 show partially broken exploded perspective views of the electrode pair 651. In FIG. 31, the wiring 719, the connector 719C, the wiring 719A, and the terminal 718 are omitted for convenience.

30 and 31, electrode fixing jigs 715 and 716 made of iron, stainless steel, or the like are provided between the cover 713 and the support 710. The electrode fixing jig 715,716 is a conductor, and it is preferable that it is comprised from the material which is hard to corrode.

The electrode fixing jig 715 is a plate body on which protrusions 715A and 715B are formed. The projections 715A and 715B are configured to penetrate the holes formed in the cover 713. The electrode 711 is mounted to be electrically connected to the protrusions 715A, 715B by the nuts 711A, 711B.

The terminal 718 is provided between the electrode fixing jig 715 and the electrode fixing jig 716 slightly behind the center of the support 710. The terminal 718 constitutes an end of the wiring 719A. The wiring 719A is one of the plurality of wirings included in the wiring 719.

The terminal 718 is disposed at a position where the electrode fixing jig 715 is attached to the cover 713 and the cover 713 is in contact with the protrusion 715A when the cover 713 is attached to the support 710. As a result, the electrode 711 is electrically connected to the terminal 718 via the protrusion 715A.

In the electrode fixing jig 716, the same projections as those of the projections 715A and 715B are formed. This protrusion projects on the left side of the support 710. A terminal different from the terminal 718 is provided between the electrode fixing jig 715 and the electrode fixing jig 716 slightly ahead of the center of the support 710. The other terminal mentioned here comprises the terminal of the wiring different from the wiring 719A among the plurality of wirings included in the wiring 719. And this other terminal is electrically connected to the projection part formed in the electrode fixing jig 716, and this projection part is connected to the electrode 712. As shown in FIG. Thereby, the said other terminal and the electrode 712 are electrically connected.

Although not shown, an insulator is provided between the electrode fixing jig 715 and the electrode fixing jig 716 between the terminal and the terminal 718. Thereby, the short circuit of the electrode 711 and the electrode 712 in the inside of which the support body 710 and the cover 713 were combined can be reliably avoided.

The electrode fixing jig 715 is screwed to the cover 713 by screws 714A, 714B, and 714C. Moreover, the electrode fixing jig 716 is screwed to the support body 710 by screws 714D, 714E, and 714F.

The packing 710B is provided between the support body 710 and the cover 713 outside the place where the cover 713 is screwed. Moreover, between the support body 710 and the electrode fixing jig 716, the packing 710C is provided outside the place where the electrode fixing jig 716 is screwed. Further, the same packing as the packing 710C is provided between the cover 713 and the electrode fixing jig 715 outside the place where the electrode fixing jig 715 is screwed.

Thereby, when the support body 710 and the cover 713 are combined, the support body 710 and the cover 713 can contain the terminal 718 and the said other terminal so that water may not enter inside.

In the electrolytic cell 605 provided with the electrode pair 651, the above-described metal ions can be supplied. The metal ions supplied from the electrolytic cell 605 are sent to the coagulation tank 606 together with the sewage.

The metal ions generated in the electrolytic cell 605 react with the sewage in the coagulation tank 606. In the coagulation tank 606, metal ions and sewage react to form procs, such as metal salts of phosphorus. This prok is sent to the coagulation sedimentation tank 607 together with the sewage, and settles in this coagulation sedimentation tank 607.

In the present embodiment described above, the first tank 606 is configured to cause the sewage after the nitrogen removal treatment to react with the metal ions by the flocculation tank 606 to agglomerate the precipitate produced by the reaction. In addition, sewage is introduced from the first tank by the flocculation settling tank 607, and a second tank for settling the aggregates in the first tank is configured. Moreover, the electrolytic cell which supplies metal ion to a 1st tank by electrolyzing an electrode by the electrolytic cell 605 is comprised.

In the present embodiment described above, the metal ions reacted with the sewage are supplied by the electrolytic reaction of the electrode. Thereby, there is an advantage that the metal ions can be supplied safely compared to the case where the metal ions are supplied by adding the flocculant to the sewage. Coagulants and pH adjusters added for flocculation are dangerous because they are agents of acids or alkalis.

In addition, compared with the case where a flocculant is added to the sewage, there is no need to adjust the pH of the sewage, which also has the advantage of allowing metal ions and sewage to react more easily.

In addition, compared with the case where a flocculant is added to the sewage, there is an advantage that a space for storing the flocculant is not required.

The electrolytic reaction in the electrode pair 651 is performed so that the concentration of the iron ions or aluminum ions eluted is 1 to 4 times the molar concentration of phosphorus in the treated water. The electrolytic reaction is controlled such that the concentration of iron ions or aluminum ions is preferably about 2.5 to 3.5 times, more preferably about 3.0 times the molar concentration of phosphorus in the treated water. For this reason, the current density at the electrode in the electrolytic reaction is controlled to be 0.1 mA / cm 2 or more, and in most cases, controlled to be about 0.3 mA / cm 2.

In this way, by controlling the current density at the electrode, it is thought that the formation of an oxide film or organic deposit on the electrode surface can be prevented and these can be removed. It is because it is thought that iron hydroxide and organic deposit which are considered to generate | occur | produce with the electrode of an anode side can be removed by the hydrogen gas which generate | occur | produces at the cathode side, and the ventilation by the acid engine 654. Therefore, when the current density in the electrolytic reaction is too low, it is considered that the amount of hydrogen gas generated on the cathode side is low so that the deposit on the anode side cannot be sufficiently removed. Then, the airflow amount of the diffuser 654 in the electrolytic unit is about 15 L / min.

For example, when the amount of daily wastewater flowing into the combined purification tank including the flocculation settling apparatus of the present invention is 10 ton, the current flowing through the electrodes 711 and 712 is controlled to about 12.3 A. Thus, it is considered that the concentration of iron ions or aluminum ions becomes about 3.0 times the molar concentration of phosphorus in the treated water by the electrolytic reaction on the electrode pair 651. The current density at each electrode can be controlled by changing the immersion area of each electrode. In each electrode pair 651, the distance between the electrode 711 and the electrode 712 is about 25 mm, and the voltage between the electrodes is always monitored. In addition, the polarity of each electrode is preferably inverted every predetermined time (for example, 24 hours).

The residence time of the sewage in the coagulation tank 606 is usually 20 minutes or more. In addition, the residence time of the sewage in the coagulation sedimentation tank 607 is usually 3 hours or more.

In addition, in the present embodiment, the residence time of the electrolytic cell 605 is preferably 3 minutes or more. The conditions for this residence time are based on the results of experiments to determine the electrolytic cell residence time. Here, the said experiment is demonstrated.

[Experiment for Determination of Electrolyzer Retention Time]

1) Experiment Method

After the electrolysis of iron was carried out for a predetermined time while aeration in the artificial liquid, the artificial liquid was transferred to a sedimentation measuring instrument (see FIG. 32) to determine the removal rate of phosphorus at various depths of the artificial liquid.

The artificial liquid is a liquid artificially synthesized to have a composition substantially the same as the sewage that is usually introduced into the coagulation tank 615. The composition of the artificial liquid is shown in Table 1.

Concentration of Components in Artificial Fluids Substance Concentration (mg / l) MgSO ₄ ㆍ 7H ₂ O 5 KCl 6 Na ₂ HPO ₄ 12H ₂ O 58 CaCl ₂ 2H ₂ O 6 FeCl ₃ 6H ₂ O One NaNO ₃ 41 NaHCO ₃ 79

In addition, in this experiment, electrolysis of iron in artificial liquid was performed using four 3 L electrolyzers, and ventilating with 3.5 L / min airflow in each electrolyzer. In this electrolysis, the number of moles of iron ions in the artificial liquid was controlled by controlling the amount of current flowing through the electrode. For example, in order to make the number of moles of iron ions in the artificial liquid about 2.5 times and about 3.0 times the number of moles of phosphorus, currents of 1.30 A and 1.55 A flowed through the electrodes in each electrolytic cell.

With reference to FIG. 32, the sedimentation measuring apparatus 700 is cylindrical and mainly consists of the accommodating part 790 which can accommodate a solution.

Moreover, the accommodating part 790 is provided with the solution extraction parts 791-796 which can extract the solution which exists in the various depth of the accommodating part 790 in the side surface. The solution extraction units 791, 792, 793, 794, 795, and 796 can extract solutions at depths of 0.3 m, 0.5 m, 0.7 m, 0.9 m, 1.1 m, and 1.3 m from the water surface, respectively.

2) Experiment result

In Fig. 33, after electrolysis of iron in the electrolytic cell for 3 minutes, the artificial liquid in the electrolytic cell is transferred to the sedimentation measuring apparatus 700, and then rapid stirring (stirring for 10 minutes at 150 rpm) and continuous stirring (at 60 rpm) are performed. The removal rate of phosphorus at various depths of the sedimentation measuring mechanism 700 in the case of 10 minutes of stirring) is shown. In this three-minute electrolysis, the amount of current supplied to the electrode was controlled so that the number of moles of iron ions eluted was 2.5 times the number of moles of phosphorus contained in the artificial liquid.

In FIG. 33, Denotes the removal rate of phosphorus when the settling time of the aggregate in the sedimentation measuring mechanism 700 is 1.5 hours. And in FIG. 33, , Indicates the removal rate of phosphorus when the settling time of the aggregate was 3.0 hours and 4.0 hours, respectively. And also in FIGS. 34-36 shown below , , Represents the removal rate of phosphorus when settling time of the aggregate was 1.5 hours, 3.0 hours, and 4.0 hours, respectively.

Phosphorus removal rate (Rp) was calculated according to the following equation (5) with the initial concentration of phosphorus in artificial liquid as Cs and the phosphorus concentration at each depth in artificial liquid after the settling time being Cd.

Rp = ｛(Cs-Cd) / Cs｝ × 100... (5)

In Fig. 33, the depth at which phosphorus removal rate is measured is each depth that can be extracted from the solution extraction sections 791-796 and a depth of 0.05 m from the water surface (indicated by point P in Fig. 32). 0.05 m is the depth considered to be a symbol part of the sedimentation measuring apparatus 700.

Referring to FIG. 33, the removal rate of phosphorus increases as the shallow portion. When the settling time of the aggregate is 3.0 hours or more, the removal rate of phosphorus becomes 60% or a value close thereto at any depth.

In the merger purification tank, generally, about 20 minutes of diffusion is performed in the flocculation tank, and the settling time in the flocculation precipitation tank is at least 3 hours.

In the present experiment, when the electrolysis time for eluting the same amount of iron ions was shorter than 3 minutes, the removal rate of phosphorus at each depth was set even if the sedimentation time in the sedimentation measuring mechanism 700 was 3 hours or more. The value was considerably lower than that shown in 33. Moreover, even if the above electrolysis was performed for longer than 3 minutes, the removal rate of phosphorus at each depth did not significantly increase with that shown in FIG.

From this, it is considered that the time of electrolysis, that is, the residence time of the sewage in the electrolytic cell 605 of the present embodiment may be 3 minutes or more.

3) Examination of presence or absence of stirring in a coagulation tank

FIG. 34 shows the removal rate of phosphorus at each depth when only stirring (quick stirring and continuous stirring) in the sedimentation measuring mechanism 700 is omitted from the experimental conditions in which the result of FIG. 33 is obtained.

When stirring is omitted with reference to Fig. 34, when the settling time is 4.0 hours, the removal rate of phosphorus is close to 60% at the symbol only. Otherwise, the removal rate of phosphorus is about 40%. In the case of the settling time of 3.0 hours, the removal rate of phosphorus is about 40% from the symbol to about 0.5 m in depth. Otherwise, the removal rate of phosphorus is about 35%. In the case of 1.5 hours of sedimentation, the removal rate of phosphorus is about 40% in the symbol, but about 20% at depths of 0.3 m to 0.7 m, about 15% at depths of 0.9 m and 1.1 m, and at 1.3 m depth The result was that little was removed.

That is, comparing the result shown in FIG. 34 with the result shown in FIG. 33, unless stirring is performed in the sedimentation measuring mechanism 700, phosphorus removal rate will fall remarkably.

From this, it is thought that in the apparatus which forms the metal salt of phosphorus and the proge of SS, ie, the coagulation tank 606 of this embodiment, phosphorus and SS in wastewater can be removed more reliably by stirring.

4) Examination of relationship between forfeiture of phosphorus in filthy water and forfeiture of iron ions to elute by electrolysis

From the experimental conditions in which the results of FIGS. 33 and 34 were obtained in FIGS. 35 and 36, the phosphorus at each depth when the number of moles of iron ions eluted in the electrolytic cell was changed from 2.5 times to 3.0 times the number of moles of phosphorus in the artificial liquid. Indicates the removal rate. That is, the result shown in FIG. 35 is a result when stirring (quick stirring and continuous stirring) was performed in the sedimentation measuring apparatus 700, and the result shown in FIG. 36 is a case where stirring was not performed in the sedimentation measuring apparatus 700. FIG. The result is.

35 and 36, the removal rate of phosphorus is higher than the case in which the artificial liquid is agitated in the sedimentation measuring apparatus 700 as a whole is not stirred.

However, regardless of the presence or absence of agitation in the sedimentation measuring mechanism 700, when the sedimentation time is 3 hours or more, the removal rate of phosphorus in the symbol is about 80%, and elsewhere, about 70%.

From this, when the electrode is electrolyzed so that the number of moles of iron ions becomes 3.0 times the number of moles of phosphorus, it is considered that phosphorus can be removed at a high efficiency of 70 to 80%, with or without agitation in the coagulation bath 606. .

[Eleventh Embodiment]

An eleventh embodiment of the present invention is shown as an apparatus for performing a process according to the flowchart shown in FIG. 24B.

The flocculation settling apparatus of this embodiment includes at least the flocculation tank 615 and flocculation settlement tank 607 shown in FIG. 24B. And compared with the wastewater treatment apparatus of 10th Embodiment, the electrolytic cell 605 shown in FIG. 26 is abbreviate | omitted, the coagulation tank 606 is changed into the coagulation tank 615, and the intermediate | middle flow volume through the piping 12 is carried out. Sewage may be introduced directly into the coagulation tank 615 from the adjustment tank 604.

And the coagulation tank 615 of this embodiment accommodates an electrolytic unit. An electrolytic unit means the unit which supplies a metal ion by electrolysis, and means including the above-mentioned electrode pair 651 (refer FIG. 27-31). Here, the structure of the electrolytic unit accommodated in the coagulation tank 615 is demonstrated, referring FIG. 37 is an exploded perspective view of the electrolytic unit accommodated in the coagulation tank 615.

The electrolytic unit is mainly composed of an electrode pair 651, an electrode fixing member 752, a flange 753, and a case 750.

The case 750 is a hollow body without a bottom. The flange 753 is mounted on the top of the case 750. The electrode fixing member 752 is mounted on the upper surface of the flange 753. In the center of the electrode fixing member 752, an electrode fixing hole 755 is formed. The outer circumferential portion of the electrode fixing hole 755 has a shape in which the end portions of the electrodes 711 and 712 are fitted. In the agglomeration tank 615, the electrode pair 651 fixes the support 710 above the electrode fixing member 752 so that the electrodes 711, 712 are positioned below the electrode fixing member 752. do. In addition, the connector 719C of the electrode pair 651 is suitably connected to a predetermined power source other than the coagulation tank 615.

Metal ions generated in the flocculation tank 615 react with the sewage in the flocculation tank 615. In the coagulation tank 615, metal ions and sewage react to form a metal salt of phosphorus and a prog of SS. This flock is sent to the coagulation sedimentation tank 607 together with sewage, and it aggregates in this coagulation sedimentation tank 607.

In the present embodiment described above, a flocculation tank 615 is configured to cause the sewage after the nitrogen removal treatment to react with the metal ions and to aggregate the precipitates generated in this reaction. In addition, sewage is introduced from the first tank by the flocculation settling tank 607, and a second tank for settling the aggregates in the first tank is configured.

In addition, as described in the tenth embodiment, the residence time of the sewage in the tank in which the electrode is provided is at least 3 minutes. Therefore, in this embodiment, it is preferable that the residence time of the wastewater in the flocculation tank 615 becomes at least 3 minutes.

The disclosed embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown by above-described not description but Claim, and it is intended that the meaning of a claim and equality and all the changes within a range are included.

The present invention can provide a sewage treatment apparatus and a flocculation sedimentation apparatus which can reliably remove a phosphorus compound from treated water.

Moreover, more phosphorus compounds can be collect | recovered in the state which can be recycled.

Further, a sewage treatment apparatus and a flocculation sedimentation apparatus which can safely aggregate certain components such as phosphorus in sewage can be provided.

Claims (17)

Sewage treatment apparatus for treating sewage, Sewage treatment unit for receiving sewage, The sewage treatment unit is provided with an active sludge tank (81) for accommodating activated sludge, an adsorption means (97A) made of a magnetic member, and a filter (97) for filtering the treated water in the active sludge tank, And the suction means (97A) is installed in the vicinity of the filter (97). delete 2. The sewage treatment apparatus according to claim 1, wherein said adsorption means (97A) is formed integrally with said filter (97). According to claim 1 or 3, further comprising an ion supply unit 70 for supplying iron ions or aluminum ions to the sewage treatment unit 61, The sewage treatment part 61 is provided with a precipitation tank 67 for precipitating agglomerates generated by the reaction of the treated water with iron ions or aluminum ions supplied from the ion supply part 70, And said adsorption means (67A) is installed in said settling tank. 5. The ion supply unit (70) according to claim 4, wherein the ion supply unit (70) connects the electrodes (71, 72) immersed in the treated water, electrode support portions (71A, 72A) supporting the electrode without being immersed in the treated water, and the electrode and the power supply. And a wiring 73A for And said wiring (73A) is integrally provided with said electrode support (71A, 72A). 6. The sewage treatment apparatus according to claim 5, wherein the electrode support portion (450) is provided with a notch portion (451) to which the electrode is fitted. Electrolytic units (51 to 54) having electrodes (51, 52), wherein the phosphors in the treated water are poorly soluble in water by electrolyzing the electrodes (51, 52) in the electrolytic units (51 to 54). As a sewage treatment apparatus 200 which precipitates as a metal salt, The electrolytic units (51 to 54) further comprise a case (54) covering only the side surfaces of the electrode. 8. The sewage treatment apparatus according to claim 7, wherein the electrolytic units (51 to 54) further comprise stirring means (53) for stirring the space surrounded by the case. The method according to claim 7 or 8, Anaerobic tanks in which anaerobic microorganisms are present (5, 10), Aerobic tank (14) in which aerobic microorganisms exist, Further comprising a settling tank 19 for settling sludge, The electrolytic units (51 to 54) are installed in the anaerobic tank (5, 10), the aerobic tank (14) or the settling tank (19). An electrolytic unit (51, 52, 59) provided with an electrode, and the electrolytic unit (51, 52, 59) electrolytically decomposes the electrodes (51, 52) so that the phosphorus component in the treated water is insoluble in water. As a sewage treatment apparatus 200 to be precipitated by Further comprising a recovery unit 160 installed adjacent to the electrolytic units 51, 52, 59 downstream of the electrolytic units 51, 52, 59 to selectively recover the metal salts. Sewage treatment unit. 11. The sewage treatment apparatus according to claim 10, wherein the recovery unit (160) includes an adsorbent (165) for trapping the metal salt. The method of claim 10 or 11, It further includes an inflow tank (5) into which the household wastewater flows, And the electrolytic unit (51, 52, 59) and the recovery unit (160) are installed in the inflow tank (5). The method of claim 10 or 11, Anaerobic tanks in which anaerobic microorganisms are present (5, 10), An aerobic tank 14 in which aerobic microorganisms are present, Further comprising a settling tank 19 for settling sludge, The electrolytic unit (51, 52, 59) and the recovery unit 160 in addition to the anaerobic tank (5, 10), the aerobic tank (14) and the settling tank (19), and also the anaerobic tank (5, 10), the aerobic tank (14) and the sewage treatment apparatus, characterized in that it is installed so that the sewage after being treated in the settling tank (19). Sewage after the nitrogen removal treatment is reacted with metal ions and sewage is introduced from Article 1 606 and from the first Article 606 to agglomerate the sediment resulting from the reaction. An agglomeration sedimentation device comprising a second article 607 for sedimentation of agglomerates of An electrolytic cell connected to an upstream side of the first tank 606, including electrodes 711 and 712, and supplying metal ions to the first tank 606 by electrolyzing the electrodes 711 and 712 ( 605, wherein the current density in the electrodes 711 and 712 is at least 0.1 mA / cm ² , The electrodes 711 and 712 are electrolyzed by supplying electric power from a predetermined power source, Wiring for connecting the electrode and the predetermined power source; Further comprising electrode support members (710, 713) for supporting the electrode, And said electrode support member (710, 713) incorporates at least a portion of said wiring (719). 15. An apparatus as claimed in claim 14, wherein said electrolyzer (605) is configured to allow sewage to stay for at least 3 minutes. Sewage after the nitrogen removal treatment is reacted with metal ions and sewage is introduced from Article 1 606 and from the first Article 606 to agglomerate the sediment resulting from the reaction. An agglomeration sedimentation device comprising a second article 607 for sedimentation of agglomerates of The first bath 606 includes electrodes 711 and 712, and supplies metal ions to the first bath 606 by electrolyzing the electrodes 711 and 712, and the electrodes 711 and 712. The current density in is at least 0.1 mA / cm ² , The electrodes 711 and 712 are electrolyzed by being supplied with power from a predetermined power source, Wiring for connecting the electrode and the predetermined power source; Further comprising electrode support members (710, 713) for supporting the electrode, And said electrode support member (710, 713) incorporates at least a portion of said wiring (719). delete