CN1286221A

CN1286221A - Sewage treating device

Info

Publication number: CN1286221A
Application number: CN00123839A
Authority: CN
Inventors: 森泉雅贵; 近藤文刚; 野吕拓哉
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 1999-08-25
Filing date: 2000-08-22
Publication date: 2001-03-07
Anticipated expiration: 2020-08-22
Also published as: KR100421515B1; CN1142893C; DE10040417A1; KR20010049876A

Abstract

Disclosed is an air-dispersed pipe 271 with electrode 260 with lift side, underside and right side covered. End of the air-dispersed pipe 271 is U-shape, top left end of the air-dispersed pipe 271 connects to pump. Cover 277 is installed on top right end of the air-dispersed pipe 271. A plurality of holes 271A is formed under the air-dispersed pipe 271. So that, when the pump supplies air, the air-dispersed pipe 271 discharges gas bubble from holes 271A. When the electrode 260 electrolyzes, the gas bubble eliminates capsule on the electrode 260. The electrode 260 and the air-dispersed pipe 271 are fixed on the supporting body 261. The air-dispersed pipe 271 could be demounted from the pump 256.

Description

Sewage treatment device

The present invention relates to a sewage treatment apparatus, and more particularly to a sewage treatment apparatus for precipitating a phosphorus component in treated water as a sparingly water-solublemetal salt.

In a conventional sewage treatment apparatus, an electrode is provided, and a phosphorus component in treated water is precipitated as a sparingly water-soluble metal salt by using metal ions generated by electrolysis of the electrode.

In fig. 28, a plate electrode 901 is mounted on a support 901a at the upper part thereof. Fig. 29 is a perspective view of the support shown in fig. 28.

Wiring is embedded in the side surface of the support 901 a.

Terminals

910 and 911 are connected to both ends of the wiring. The terminal 911 is connected to a power supply for supplying electric power to the electrode 901. The terminal 910 is exposed to the side surface of the support 901a and can be connected to the electrode 901.

As shown in fig. 28, when the electrode 901 is mounted on the support 901a, the terminal 910 is covered with the electrode 901.

However, since the treated water may enter the gap between the holder 901a and the electrode 901, the terminal 910 may be corroded.

When the terminal 910 is corroded, it adheres to the electrode 901, and therefore, the electrode 901 is troublesome to replace.

In addition, when the terminal 910 is corroded, an obstacle is generated when power is supplied to the electrode 901. However, since it is difficult to replace the terminal 910, which is a part of the wiring, in the conventional sewage treatment apparatus, the electrolytic efficiency of the electrode 901 is lowered due to corrosion of the terminal 910.

Further, the conventional sewage treatment apparatus is provided with a tubular member which generates bubbles in the vicinity of the electrode 901, and a coating film generated on the surface of the electrode 901 is removed by the bubbles generated by the tubular member at the time of electrolysis of the electrode 901.

However, suspended matter contained in the sewage sometimes enters the inside of the tubular member, and in this case, sufficient bubbles cannot be generated. In this case, the film formed on the surface of the electrode 901 cannot be sufficiently removed, and the electrolytic efficiency of the electrode 901 is lowered.

In the sewage treatment apparatus, if the electrolysis efficiency of the electrode 901 is lowered, the phosphorus component in the sewage cannot be sufficiently removed.

Further, there are some conventional sewage treatment apparatuses that are disposed underground. This type of sewage treatment plant is usually inspected and repaired by opening the manhole cover and extending the worker's handle into the ground.

However, when the inspection and maintenance are performed underground, the inspection and maintenance may not be performed carefully. In a sewage treatment apparatus, if inspection and maintenance cannot be performed carefully, sewage treatment capability cannot be sufficiently exhibited. This also makes it difficult to reliably remove the coagulated phosphorus compound from the treated water.

Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a sewage treatment apparatus capable of reliably removing phosphorus compounds from treated water.

A sewage treatment apparatus of the present invention is installed underground for treating sewage, and includes a sewage treatment section for receiving sewage and an ion supply section for supplying iron ions or aluminum ions to the sewage treatment section, wherein the ion supply section includes an electrode attached to a manhole cover.

In this way, the electrode can be moved to the ground by moving the manhole cover to the ground, and therefore, the maintenance of the electrode can be easily and reliably performed.

Therefore, in the sewage treatment apparatus, the phosphorus compound generated by the electrolytic reaction of the electrode can be surely removed.

Further, the sewage treatment apparatus of the present invention is preferably provided with a detection means capable of detecting whether or not the electrode is immersed in the treatment water.

Thus, the electrodes can be prevented from being not immersed in the treatment water.

Therefore, by mounting the electrode on the manhole cover, the above-described expected problems can be avoided.

Another sewage treatment apparatus of the present invention comprises an electrode for electrolyzing an electrode by supplying electric power from a predetermined power supply to the electrode; the electrode support device is characterized by further comprising an electrode support member for supporting the electrode, a wire for connecting the electrode with a predetermined power supply, a terminal provided at the end of the wire on the side of the electrode, and a connecting member which is attached to the electrode support member, is detachable from the electrode support member, and electrically connects the terminal and the electrode; the terminal is housed in the electrode support member and does not contact the outside of the electrode support member.

According to the present invention, the terminal attached to the wiring is incorporated without contacting the outside of the electrode support member, and is connected to the electrode through the connection member. That is, in the sewage treatment apparatus,the terminals are prevented from being exposed, and the terminals are directly connected to the electrodes by detachable connection members instead of the terminals.

Therefore, terminal corrosion can be prevented. Thus, it is possible to avoid the inhibition of the supply of electric power to the electrode due to the corrosion of the terminal. In addition, the sewage treatment apparatus is continuously used, and in case the connection member is corroded, the replacement thereof is easy.

Further, in the sewage treatment apparatus according to the present invention, it is preferable that at least a part of the wiring is incorporated in the electrode support member.

Thus, the wiring can be arranged compactly and without being easily immersed in water.

Further, according to the sewage treatment apparatus of the present invention, the electrode support member may support a plurality of electrodes, and preferably, the electrode support member includes an insulator disposed between 1 electrode among the plurality of electrodes and another electrode.

Thus, the electrodes can be supported compactly by the electrode support member while preventing short-circuiting.

Another sewage treatment apparatus according to the present invention includes an electrode for electrolyzing the electrode, and a tube having a hole formed therein, the tube being detachably connected to a predetermined pump, and bubbles being discharged to the vicinity of the electrode through the hole.

According to the present invention, the surface of the electrode is cleaned by the bubbles discharged from the tube, and the tube can be detached from the pump, so that the tube can be easily cleaned.

Therefore, in the sewage treatment apparatus, the electrode surface canbe continuously cleaned with the bubbles discharged from the pipe.

Further, the sewage treatment apparatus of the present invention preferably includes an electrode support member for supporting the electrode and the pipe.

In this way, when the electrode is repaired or replaced, the tube supported by the electrode support unit can be removed from the pump together with the electrode and cleaned.

Therefore, the maintenance work is easy in the sewage treatment apparatus.

In addition, in the sewage treatment apparatus of the present invention, when the electrode is supplied with electric power from a predetermined power supply, electrolysis is generated; further comprises a wiring for connecting a predetermined power source to the electrode, and an electrode supporting member for supporting the electrode; preferably, the electrode support member has at least a part of the wiring incorporated therein.

Further, the sewage treatment apparatus of the present invention is characterized by further comprising: an anaerobic tank into which sewage is introduced and in which anaerobic microorganisms are present, an aerobic tank into which sewage is introduced and in which aerobic microorganisms are present, and a settling tank into which sewage is introduced and in which sludge is settled; the electrodes are immersed in the sewage inside the anaerobic tank, aerobic tank or settling tank.

In this way, in the sewage treatment apparatus, the metal ions generated by the electrolysis of the electrodes agglomerate phosphorus as precipitates. That is, in the sewage treatment apparatus, it is not necessary to provide a separate coagulation tank.

The sewage treatment apparatus of the present invention further includes an electrolytic bath for introducing only sewage and electrolyzing the electrode, wherein the electrode is immersed in the sewage in the electrolytic bath.

In this way, in the sewage treatment apparatus, the metal ions generated by the electrolysis of the electrodes agglomerate phosphorus as precipitates. That is, in the sewage treatment apparatus, it is not necessary to provide a separate coagulation tank. Since only the sewage is introduced into the electrolytic cell, the inhibition of the electrolysis of the electrodes by sludge or the like can be prevented.

The above and other objects, features and advantages of the present invention will be more fully understood from the following description with reference to the accompanying drawings.

FIG. 1 is a view showing a sewage treatment system including a sewage treatment apparatus according to a first embodiment of the present invention.

FIG. 2 is a view showing the detailed structure of the electrolytic cell and its vicinity shown in FIG. 1.

Fig. 3 is a view showing the structure of the electrode and the electrode support portion in fig. 1.

FIG. 4 is a view showing the electrode and the electrode support part of FIG. 3 in a combined state for mounting in an electrolytic cell.

Fig. 5 is a perspective view of the electrode support in fig. 3.

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

Fig. 7 is a view showing an electrode support portion having a cutout portion for supporting two electrodes.

Fig. 8 is a view showing a state where the assembled electrode and electrode support portion are housed in a case.

FIG. 9 is a view showing a sewage treatment apparatus according to a second embodiment of the present invention.

FIG. 10 is a view showing a sewage treatment apparatus according to a third embodiment of the present invention.

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

Fig. 12 is a partial perspective view of the magnet of fig. 10.

FIG. 13 is a view showing a sewage treatment apparatus according to a fourth embodiment of the present invention.

FIG. 14 is a view showing a sewage treatment apparatus according to a fifth embodiment of the present invention.

FIG. 15 is a view showing a sewage treatment apparatus according to a sixth embodiment of the present invention.

FIG. 16 is a view showing a sewage treatment apparatus according to a seventh embodiment of the present invention.

Fig. 17 is a view illustrating a state in which the electrode of fig. 16 is installed on a manhole cover.

FIG. 18 is a vertical sectional view showing a sewage treatment system including a sewage treatment apparatus according to an eighth embodiment of the present invention.

Figure 19 is a cross-sectional view of the groove shown in figure 18.

Fig. 20 is a perspective view of the counter electrode in fig. 18.

Fig. 21 is a partially cut-away exploded perspective view of the counter electrode in fig. 18.

Fig. 22 is a partially cut-away exploded perspective view of a part of the counter electrode in fig. 20.

Fig. 23 is a partially cut-away exploded perspective view of a part of the counter electrode in fig. 20.

FIGS. 24A and 24B are views showing electrodes and members arranged around the electrodes in an electrolysis cell according to a ninth embodiment of the present invention.

FIG. 25 is a view schematically showing an electrolysis cell according to a ninth embodiment of the present invention.

FIG. 26 is a view illustrating a state in which the electrode shown in FIG. 24A is mounted on a support.

FIGS. 27A and 27B are views showing modifications of the electrode and the members disposed around the electrode in the electrolysis cell according to the ninth embodiment of the present invention.

FIG. 28 is a perspective view of an electrode attached to a support in a conventional sewage treatment apparatus.

Fig. 29 is a perspective view of the support in fig. 28.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The sewage treatment apparatuses of the embodiments described below are mainly used in large-scale sewage treatment facilities for treating domestic sewage and factory sewage, but may also be used in medium-and small-scale sewage treatment facilities such as a domestic combined septic tank. Further, the sewage treatment apparatuses of the respective examples can perform coagulation sedimentation treatment of phosphorus compounds contained in domestic wastewater, wastewater from plating plants, and the like.

First embodiment

As shown in fig. 1, the tank 1 is buried underground. The tank 1 is divided into a first anaerobic filter bed tank 5, a second anaerobic filter bed tank 10, a contact aeration tank 14, a treatment water tank 19, and a disinfection tank 21 by a first partition wall 2, a second partition wall 3, and a third partition wall 4. The upper part of the tank 1 is covered by a number of manhole covers 28.

The domestic wastewater flows into the first anaerobic filter bed tank 5 through the inflow port 6. The first anaerobic filter bed 7 is disposed in the first anaerobic filter bed tank 5. In the first anaerobic filter bed tank 5, the hardly decomposable foreign matter mixed in the inflowing domestic wastewater is precipitated and separated, and the organic matter in the domestic wastewater is anaerobically decomposed by the anaerobic microorganisms attached to the first anaerobic filter bed 7. In addition, in the first anaerobic filter bed tank 5, organic nitrogen in the domestic wastewater is anaerobically decomposed by ammoniacal nitrogen.

The first transfer pipe 8 supplies the treated water anaerobically decomposed in the first anaerobic filter bed tank 5 to the second anaerobic filter bed tank 10 through the first water supply port 9. The first water supply port 9 penetrates the upper portion of the first partition wall 2.

The second anaerobic filter bed tank 10 is separated from the first anaerobic filter bed tank 5 by means of a first partition wall 2. The second anaerobic filter bed 11 is disposed in the second anaerobic filter bed tank 10. The floating matter is captured by the second anaerobic filter bed 11. In addition, the organic matter is anaerobically decomposed by the anaerobic microorganisms in the second anaerobic filter bed 11, and as a result, organic nitrogen is generated. Organic nitrogen is anaerobically decomposed by ammoniacal nitrogen.

The second transfer pipe 12 supplies the treated water anaerobically decomposed in the second anaerobic filter bed tank 10 to the contact aeration tank 14 through the second water supply port 13. The second water supply port 13penetrates the upper portion of the second partition wall 3. The discharge port 31 of the discharge device 32 is disposed in the second draft tube 12, and the discharge device 32 is connected to the third blower 30. Air is sent from the third blower 30 to the ejector 32, and the ejector 32 blows the air from the outlet 31 into the second flow duct 12. Thus, the supply of the treated water from the second anaerobic filter bed tank 10 to the contact aeration tank 14 in the second transfer pipe 12 is facilitated.

The treated water after being anaerobically treated in the second anaerobic filter bed tank 10 flows into the contact aeration tank 14 through the second transfer pipe 12. The contact material 15 provided in the contact aeration tank 14 promotes the culture of aerobic microorganisms. The first air diffusion pipe 16 is disposed near the bottom of the contact aeration tank 14 and has a plurality of air blow-out ports. The first air-diffusing pipe 16 is connected to the first blower 17, and discharges air supplied from the first blower 17 from the air outlet to maintain the interior of the contact aeration tank 14 in an air-conditioned state. In this way, in the contact aeration tank 14, the treated water is aerobically decomposed by the aerobic microorganisms, and at the same time, the ammonium nitrogen is decomposed into nitrate nitrogen by the action of the nitrifying bacteria. The nitrifying bacteria are generally referred to as ammonia oxidizing bacteria and nitrifying bacteria.

A biofilm adheres to the contact material 15, and the biofilm grows and grows larger. When air is supplied from the first blower 17 to the first air-diffusing duct 16, the air is discharged from the air outlet of the first air-diffusing duct 16, and the biofilm attached to the contact material 15 is peeled off.

The treatment tank 19 is separated from the contact aeration tank 14 by a third partition wall 4. The third transfer pipe 29 is connected to the first pump 18, and the supernatant of the treated water decomposed by aerobic decomposition in the contact aeration tank 14 is supplied to the treated water tank 19 through the communication port 20 by the operation of the first pump 18. The communication port 20 penetrates the upper portion of the third partition wall 4.

The supernatant of the treated water tank 19 flows into the sterilizing tank 21. A sterilizer 22 is provided inside the sterilizing tank 21. The treated water flowing into the disinfecting tank 19 is disinfected by chemicals such as chlorine contained in the disinfecting apparatus 22. The sterilized treated water is discharged out of the tank 1 through the water discharge port 23.

The first return pipe 24 is a pipe for communicating the treatment tank 19 with the electrolytic bath 37. The second air-dispersing pipe 25 is disposed in the first return pipe 24, forms a plurality of air outlets, and is connected to the second blower 26. The second air-diffusing duct 25 discharges the air supplied from the second blower 26 from the air outlet. Thus, a predetermined amount of the supernatant in the treatment tank 19 is sucked into the first return pipe 24 and transferred to the electrolytic bath 37.

Electrodes

41 and 42 are disposed in the electrolytic bath 37. A third air diffusing pipe 40 is disposed below the

electrodes

41 and 42. The third air-dispersing duct 40 is formed with a plurality of air blowing ports and is connected to the fourth blower 39. When air is sent from the fourth blower 39, the third air-diffusing duct 40 blows out the air from the air-blowing port, and removes a film such as a non-moving film due to a biofilm, nitrate ions, or the like on the surfaces of the

electrodes

41 and 42. Further, the

electrodes

41 and 42 are preferably provided near the wall surface of the electrolytic bath 37, so that the film can be removed more effectively by the air blown out from the third air diffuser 40.

The treated water in the electrolytic bath 37 is discharged to the first anaerobic filter bed tank 5 through the discharge port 47. A cover 36 is provided at a discharge port 47 of the electrolytic bath 37. The cover 36 is connected to the float 35. In the vicinity of the lid 36, a water level sensor 48 for detecting the water level of the first anaerobic filter bed tank 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, 42 are made of, for example, iron or aluminum. One of the

electrodes

41 and 42 is a positive electrode, and the other is a negative electrode, and the power supply device 38 supplies a voltage to the

electrodes

41 and 42. Next, electrolytic reactions in the + pole and the-pole when the

electrodes

41 and 42 are made of iron will be described.

+ pole: …(1)

-a pole: …(2)

in addition, 2-valent iron ion (Fe) generated at the + pole²⁺) Oxidized by air to become 3-valent iron ions (Fe)³⁺). When the

electrodes

41 and 42 are made of aluminum, the negative electrode reaction is not changed, and the positive electrode electrolysis reaction is expressed by the following formula (3).

+ pole: …(3)

in the present embodiment, a case where the

electrodes

41 and 42 are made of iron will be described below, and iron may be changed to aluminum in all aspects except for the specific description.

Iron ion (Fe) of valence 3 generated by the electrolytic reaction and oxidation reaction of the formula (1)³⁺) The phosphorus compounds in the treated water from the first return pipe 24 are condensed. In addition, Fe is used³⁺The main contents of the coagulation reaction formula of the phosphorus compound (4) are shown in the following formula.

…(4)

A valve 43 is formed at the bottom of the electrolytic bath 37, and the valve 43 is used for removing the condensate, sludge, and the like inside the electrolytic bath 37 from the electrolytic bath 37. When the valve 43 is opened, sludge, aggregates, and the like in the electrolytic bath 37 move to the first anaerobic filter bed tank 5.

FIG. 2 is a view showing the structure of the electrolytic bath 37 and its vicinity. As shown in FIG. 2, the treated water fed from the first return pipe 24 flows into the inlet 46 of the electrolytic bath 37. A third air diffusing pipe 40 is provided near the

electrodes

41 and 42. The third air dispersing pipe 40 supplies air to the vicinity of the

electrodes

41, 42.

A cover 36 covering the discharge port 47 is connected to the float 3. The lower end of the lid 36 is connected to the outlet 47 with a hinge 34, so that the lid 36 can open and close the outlet 47. When the lid 36 is opened, the water level of the solution in the first anaerobic filter bed tank 5 is assumed to be 100A, which is the water level of the solution not flowing into the electrolytic bath 37 through the

drain

47, and 100B, which is the water level of the solution flowing into the electrolytic bath 37 through the drain 47.

When the water level of the first anaerobic filter bed tank 5 is 100A, the float 35 is positioned at 35A in fig. 2, and therefore the cover 36 is in a state of opening the drain port 47 as indicated by 36A. When the water level of the first anaerobic filter bed tank 5 is 100B, the float 35 is positioned at 35B in fig. 2, and the cover 36 is in a state of closing the drain port 47 as indicated by 36B. Therefore, in the present embodiment, the discharge port 47 is covered with the cover 36, and the cover 36 is connected to the float 35, so that the sludge mixed in the domestic wastewater flowing in from the inflow port 6 does not directly flow into the electrolytic bath 37. The water level 100A also includes: that is, although the solution in the first anaerobic filter bed tank 5 flows into the electrolytic bath 37, the sludge and the like in the solution do not flow into the water level in the electrolytic bath 37.

The electrolytic bath 37 is provided with a control unit, not shown, which controls the opening and closing of the valve 43, the value of the current flowing through the

electrodes

41 and 42, the voltage value between the

electrodes

41 and 42, the amount of air blown out from the third air diffuser 40, the polarity of the voltage applied to the

electrodes

41 and 42, and the like.

The water level sensor 48 is provided for detecting whether the water level of the first anaerobic filter bed tank 5 has reached a predetermined water level. The detection output of the water level sensor 48 is input to the control unit. The predetermined water level here means, for example, a water level at which the domestic wastewater flowing in through the inlet 6 directly flows into the electrolytic bath 37. When the water level sensor 48 detects that the predetermined water level has been reached, the control section may issue a warning by sound, display, or the like. With the control unit thus configured, the inflow amount of the wastewater passing through the inflow port 6 can be adjusted, so that the domestic wastewater flowing in from the inflow port 6 does not directly flow into the electrolytic bath 37, and the dross can be more reliably prevented from flowing into the electrolytic bath 37. In addition, the above-mentioned predetermined water level may be a water level: that is, although the solution in the first anaerobic filter bed tank 5 flows into the electrolytic bath, the sludge and the like in the solution do not flow into the water level in the electrolytic bath 37.

The worker who performs maintenance of the sewage treatment system of the present embodiment can determine whether the domestic wastewater flowing in from the inflow port 6 directly flows into the electrolytic bath 37 or not, based on the presence or absence of the warning. Therefore, in the case where the lid 36 and the float ball 35 are not provided, it is possible to judge whether or not the dross is deposited in the vicinity of the

electrodes

41 and 42 based on the presence or absence of the warning, and therefore, it is possible to easily judge whether or not the electrolytic bath 37 needs to be cleaned.

In addition, when the water level sensor 48 detects that the water level reaches the predetermined water level, the control unit may increase the air supply amount of the third air dispersing pipe 40. By controlling the above by the controller, even if the dross flows into the vicinity of the

electrodes

41 and 42, the amount of air in the third air diffusing pipe 40 is increased, and therefore the dross can be discharged to the outside of the electrolytic bath 37. Thus, the accumulation of dross near the

electrodes

41, 42 can be reliably avoided.

That is, in the above embodiment, by providing at least one of the assembly of the float 35 and the cover 36 and the water level sensor 48, deposition of the dross near the

electrodes

41 and 42 can be prevented.

The

electrodes

41, 42 are attached to the

electrode support portions

41A, 42A, respectively. The

electrode support portions

41A and 42A are positioned above

theelectrodes

41 and 42, and are supported by

support rods

37A and 37B, which will be described later, so as not to be immersed in the treatment water in the electrolytic bath 37. Fig. 3 shows the structure of the

electrodes

41, 42 and the electrode supports 41A, 42A. Fig. 4 shows a state in which the

electrodes

41 and 42 and the electrode supports 41A and 42A are assembled to be attached to the electrolytic bath 37.

As shown in fig. 3 and 4, the

electrodes

41 and 42 are screwed to the

electrode support portions

41A and 42A, respectively, at their upper portions. A spacer 405 is attached to a surface of the electrode support 41A facing the electrode support 42A. As shown in fig. 4, the electrode support portion 41A and the electrode support portion 42A are combined and fixed to each other by spacers 405. By appropriately adjusting the width of the spacer 405, the distance between the electrode 41 and the electrode 42 can be adjusted.

Next, the structure of the

electrode support portions

41A and 42A will be described. Fig. 5 is a perspective view of the electrode support portion 41A. The electrode support 41A includes wiring for connecting the power supply device 38 and the electrode 41. One end of the wiring is a connector 410 and the other end is a connector 411. The electrode 41 is screwed to the electrode support 41A and electrically connected to the connector 410. The connector 411 is electrically connected to the power supply device 38. Thus, the electrode 41 is screwed to the electrode support 41A, and is electrically connected to the power supply device 38. The electrode support portion 42A also includes the wiring of the two connectors, similarly to the electrode support portion 41A. The electrode 42 is screwed to the electrode support portion 42A, and is electrically connectable to the power supply device 38.

Since the

electrodes

41 and 42 and the electrode supporting portions 41Aand 42A are configured in this manner, in the sewage treatment system of the present embodiment, the wires connecting the

electrodes

41 and 42 and the power supply device 38 can be prevented from lying in the treated water. In addition, the connector, which is the connection part, is prevented from being corroded by being immersed in the processing water.

FIG. 6 is a perspective view of the electrolytic bath 37. 2

support rods

37A and 37B are provided at predetermined intervals on the upper part of the electrolytic bath 37. The

electrode support portions

41A and 42A are provided on the electrolytic bath 37 with their right and left lower ends disposed on the

support rods

37A and 37B. That is, in this state, the

electrodes

41 and 42 are sandwiched by the

support rods

37A and 37B, respectively.

In the electrolytic bath 37, in order to avoid the positional deviation of the

electrodes

41 and 42, the electrodes may be supported by 1 electrode support part provided with a notch. Fig. 7 shows an electrode support portion having a cutout portion for supporting the

electrodes

41 and 42.

The electrode support 450 has notches 451 formed on both front and rear surfaces thereof, into which the upper portions of the

electrodes

41 and 42 can be fitted, respectively. The upper portions of the

electrodes

41 and 42 are fitted into the notches 451 and screwed together. Thus, the positions of the

electrodes

41 and 42 in the electrolytic bath 37 are more reliably fixed, and the iron ion distribution in the electrolytic bath 37 is stabilized. Therefore, the reaction of formula (4) can be stably caused in the electrolytic bath 37. Thus, the sewage treatment apparatus of the present embodiment is stable in sewage treatment capability. When the electrode support 450 is set in the electrolytic bath 37, the lower surfaces of the right end 450A and the left end 450B contact the

support rods

37A and 37B. Thus, the

electrodes

41 and 42 are sandwiched by the

support rods

37A and 37B, respectively, in the state of being disposed in the electrolytic bath 37.

When the electrode support 450 and the

electrodes

41 and 42 are assembled and transported, they are preferably stored in a cassette and transported, as shown in fig. 8. Specifically, when the assembled electrode support 450 and the

electrodes

41 and 42 are housed in the case 460, the portions of the

electrodes

41 and 42 are housed in the case 460. When stored, the right end 450A and the left end 450B of the electrode support 450 are screwed to the case 460 by screws 461 and 462, respectively.

Second embodiment

The second embodiment of the present invention is explained below. The sewage treatment apparatuses according to the second to sixth embodiments are mainly used for removing phosphorus compounds in sewage, and may be used alone or in combination with a treatment tank containing anaerobic microorganisms, such as an anaerobic filter bed tank.

As shown in fig. 9, the activated sludge tank 61 contains activated sludge, and sewage is fed from another device or the like through an inflow port 69. The first air diffusing pipe 62 is disposed at the bottom of the activated sludge tank 61. The first air-diffusing duct 62 is connected to the first blower 65, and discharges the air supplied from the first blower 65 from the air outlet. Thus, the activated sludge tank 61 is kept in an aerobic state, and the treated water is subjected to aerobic decomposition by aerobic microorganisms, and ammoniacal nitrogen is decomposed into nitrate nitrogen by nitrification.

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 bath 70 through the circulation pipe 63 by the pump 64. Further, the supernatant of the treated water in the activated sludge tank 61 is sent to the precipitation tank 67 through the flow shift pipe 77.

The electrolytic cell 70 is provided with

electrodes

71, 72, which may be made of iron or aluminum. The

electrodes

71 and 72 are connected to a power supply device 73 via a wire 73A, and iron ions or aluminum ions are supplied to the electrolytic bath 70 by electrolysis. When these metal ions are supplied, the phosphorus compound is condensed in the electrolytic bath 70, for example, according to the above formula (4). A second air diffusing pipe 74 is disposed below the

electrodes

71, 72 of the electrolytic bath 70. The second air dispersing pipe 74 is connected to the second blower 66. Air supplied from second blower 66 is discharged from the air outlet to the vicinity of

electrodes

71 and 72. A valve 75 is provided below the second air dispersing pipe 74. The valve 75 is openable and closable, and normally closed, and is appropriately opened when sludge or aggregate in the electrolytic bath 70 is to be discharged to the activated sludge tank 61.

The activated sludge tank 61 is provided with a magnet 61A. The aggregates of the phosphorus compounds generated in the electrolytic bath 70 are adsorbed by the magnet 61A. Thus, the sewage treatment apparatus of the present embodiment can remove the phosphorus compounds in the treated water more reliably. The aggregates of the phosphorus compounds are adsorbed on the magnet 61A in an oxidized form. In the present embodiment, the magnet 61A constitutes an attracting mechanism formed of a magnetic member.

Like the

electrodes

41 and 42, the

electrodes

71 and 72 are supported at their upper portions by electrode supports 71A and 72A, and the electrode supports 71A and 72A have the same shape as the electrode supports 41A and 42A.

Similarly to the

electrode support portions

41A and 42A, the

electrode support portions

71A and 72A also enclose the wiring 73A having two connectors, respectively.

Similarly to electrode support portion 450,

electrode support portions

71A and 72A are also formed with cutouts into which the upper portions of

electrodes

71 and 72 can be fitted, respectively.

The activated sludge is fed from the activated sludge tank 61 into the electrolytic bath 70 of this example together with the treated water. The reaction product of the above formula (4) is relatively easily aggregated around the activated sludge from the activated sludge tank 61, and each aggregate becomes large. Therefore, the reaction product of the above formula (4) is easily precipitated as an aggregate, and the electrolytic reaction of the

electrodes

71, 72 is relatively fast even for a long period of time during the treatment in the electrolytic bath 70. The distance between the

electrodes

71 and 72 is preferably 2cm or more in consideration of the size of sludge.

In the sedimentation tank 67, the supernatant of the sent treatment water is discharged through the discharge port 78. Sludge 68 accumulates at the bottom of the settling tank 67. Sludge 68 from the settling tank 67 is periodically removed.

According to the sewage treatment apparatus of the present embodiment, since the magnet 61A is provided, the removal rate of the phosphorus compound is as high as about 90 to 95%, although the removal rate varies depending on the scale of the apparatus.

Third embodiment

The third embodiment of the present invention is explained below.

As shown in fig. 10, activated sludge is contained in the activated sludge tank 81, and sewage is fed from another apparatus through the inflow port 89. A first air diffusing pipe 82 is disposed at the bottom of the activatedsludge tank 81. The first air-dispersing duct 82 is connected to the first blower 85, and discharges air supplied from the first blower 85 from the air outlet.

One end of the circulation pipe 83 is inserted into the activated sludge tank 81, and the treated water in the activated sludge tank 81 is sent to the electrolytic bath 90 through the circulation pipe 83 by means of the pump 84. A flow transfer pipe 98 having a membrane 97 at its tip is disposed in the activated sludge tank 81, and a part of the membrane 97 is immersed in the activated sludge tank 81. The treated water in the activated sludge tank 81 is discharged to the outside of the activated sludge tank 81 through the membrane 97 by the pump 87 via the flow-through pipe 98. The membrane 97 may be, for example, a flat membrane or a hollow fiber membrane having a pore diameter of about 0.05 to 1 μm.

The electrolytic cell 90 is provided with

electrodes

91, 92, which may be made of iron or aluminum. The

electrodes

91 and 92 are connected to a power supply 93, and iron ions or aluminum ions are supplied to the electrolytic cell 90 by electrolysis of the electrodes. A second air diffusion pipe 94 is disposed below the

electrodes

91, 92 of the electrolytic cell 90. The second air dispersing pipe 94 is connected to the second blower 86. The air supplied from second blower 86 is discharged from the air outlet to the vicinity of

electrodes

91 and 92. A valve 95 is provided below the second air dispersing pipe 94. The valve 95 is openable and closable, and normally closed, and is appropriately opened when sludge or aggregate in the electrolytic bath 90 is to be discharged to the activated sludge tank 81. Sludge is accumulated in the bottom of the activated sludge tank 81, and the sludge is periodically removed.

The

electrodes

91 and 92 are supported at their upper portions by electrode support portions (not shown) having thesame shape as the

electrode support portions

41A and 42A, similarly to the

electrodes

41 and 42 described above.

The film 97 is mounted on the magnet 97A. The structure of the film 97 and the magnet 97A will be described in detail below. Fig. 11 is a side view of the film 97 and the magnet 97A.

As shown in fig. 10 and 11, the magnet 97A has a ring shape. The film 97 covers the central hole of the magnet 97A from both the front and back sides. Fig. 12 is a partial perspective view of the magnet 97A. An opening is formed in the upper portion of the magnet 97A, and one end of the flow shift pipe 98 is connected to the opening. That is, in the sewage treatment apparatus of the present embodiment, the treated water coming near the magnet 97A is introduced into the flow pipe 98 through the membrane 97.

In this embodiment, the magnet 97A is provided in the vicinity of the film 97, so that the aggregates of the phosphorus compound are adsorbed to the magnet 97A, and the adhesion to the film 97 is suppressed, whereby clogging of the film 97 can be suppressed.

In this embodiment, the precipitation tank 67 in the second embodiment is changed to the membrane 97, so that the sewage treatment apparatus can be further downsized.

In addition, in this example, since the magnet 97A is provided and the treated water is filtered by the membrane 97, the removal rate of the phosphorus compound can be as high as 90% or more.

In the present embodiment described above, the magnet 97A constitutes an attracting means formed of a magnetic member. The membrane 97 constitutes a filter for filtering the treated water in the activated sludge tank. In the present embodiment, the magnet 97A and the film 97 are integrated, but the present invention is not limited to such a configuration. It is naturally preferable to form them integrally, but they are not necessarily formed integrally as long as they are provided close to each other.

Fourth embodiment

The fourth embodiment of the present invention is explained below.

As shown in fig. 13, the activated sludge tank 101 is partitioned into a portion containing activated sludge and a portion not containing activated sludge by a partition plate 107. The partition plate 107 is not connected to the activated sludge tank 101 below, and a gap is formed, so that the treated water and the sludge can move. The sewage is fed into the activated sludge tank 101 through an inflow port 109 from another apparatus or the like. A first air diffusing pipe 102 is disposed at the bottom of the activated sludge tank 101. The first air-diffusing duct 102 is connected to the first blower 105, and discharges air supplied from the first blower 105 from the air 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 bath 110 through the circulation pipe 103 by the pump 104. The supernatant of the treated water in the activated sludge tank 101 is discharged to the outside of the activated sludge tank 101 through the discharge port 118.

The cell 110 is provided with electrodes 111, 112, which may be made of iron or aluminium. The electrodes 111 and 112 are connected to a power supply 113, and iron ions or aluminum ions are supplied to the electrolytic cell 110 by electrolysis of the electrodes. A second air diffusion pipe 114 is disposed below the electrodes 111, 112 of the electrolytic bath 110. The second air dispersing pipe 114 is connected to the second blower 106. The air supplied from second blower 106 is discharged from the air outlet to the vicinity of electrodes 111 and 112. A valve 115 is provided below the second air dispersing pipe 114. The valve 115 is openable and closable, and normally closed, and is appropriately opened when sludge or aggregate in the electrolytic bath 110 is to be discharged to the activated sludge tank 101.

A magnet 107A is attached to the surface of the partition plate 107 on the side not containing activated sludge. The aggregates of the phosphorus compounds in the aggregates in the electrolytic bath 110 can be efficiently collected by the magnet 107A.

As in this example, the phosphorus compound aggregates are adsorbed and collected by the magnet 107A, and the phosphorus compound in the treated water can be collected in a form that can be easily regenerated. Thus, the sewage treatment apparatus of the present embodiment can realize high efficiency of phosphorus regeneration at the present day when phosphorus resources are gradually depleted.

In the sewage treatment apparatus of the present embodiment described above, the partition plate 107 is provided, and the sedimentation tank 67 is provided in the activated sludge tank 61 of the sewage treatment apparatus shown in FIG. 9.

According to the sewage treatment apparatus of the present embodiment, the removal rate of the phosphorus compound can be as high as about 90 to 95%, although the removal rate varies depending on the scale of the apparatus.

Fifth embodiment

The fifth embodiment of the present invention is explained below.

As shown in FIG. 14, the entire structure of the sewage treatment apparatus of the present embodiment is substantially the same as that of the sewage treatment apparatus shown in FIG. 9, and therefore, the same components as those of the sewage treatment apparatus shown in FIG. 9 are denoted by the same reference numerals, and the description thereof will beomitted.

In the sewage treatment apparatus of this embodiment, the treated water in the activated sludge tank 61 is sent to the electrolytic bath 70 through the circulation pipe 63 by the pump 64. The supernatant of the electrolytic bath 70 is sent to the precipitation bath 67 through the outflow pipe 76. The supernatant in the precipitation tank 67 is discharged from the sewage treatment apparatus through the discharge port 78.

A magnet 67A is provided on the outflow pipe 76 in the precipitation tank 67. Thus, the aggregates of the phosphorus compounds generated in the electrolytic bath 70 can be adsorbed by the magnet 67A more efficiently and in a form separated from other aggregates or sludge. Therefore, the sewage treatment apparatus of the present embodiment can improve the regeneration efficiency of phosphorus more than the fourth embodiment.

Sixth embodiment

The sixth embodiment of the present invention is explained below.

As shown in FIG. 15, the entire structure of the sewage treatment apparatus of the present embodiment is substantially the same as that of the sewage treatment apparatus shown in FIG. 13, and therefore, the same components as those of the sewage treatment apparatus shown in FIG. 13 are denoted by the same reference numerals, and the description thereof will be omitted.

In the sewage treatment apparatus of the present embodiment, from the inlet 109, the activated sludge tank 101 is partitioned into a region for containing activated sludge, a region for containing the electrodes 111 and 112, and a region for precipitating sludge 108 in this order by the partition plates 107 and 150.

The treated water fed from the inlet 109 is contained in a region containing sludge in the activated sludge tank 101, and the supernatant in this region is fed to a region containing the electrodes 111 and 112.

The treated water and the aggregates below the region where the electrodes 111 and 112 are housed are sent to a region where the sludge 108 is precipitated, and the supernatant in this region is discharged out of the activated sludge tank 101 through the discharge port 118.

The partition plate 150 has a magnet 150A on the wall surface on the side of the sludge 108 sedimentation region. As a result, the phosphorus compound aggregates generated in the region where the electrodes 111 and 112 are accommodated are adsorbed by the magnet 150A more efficiently and in a form separated from other aggregates or sludge.

The treated water discharged to the outside of the activated sludge tank 101 is preferably sent to an anaerobic filter bed tank (tank for housing anaerobic microorganisms) provided separately.

The activated sludge tank 101 includes a side wall inclined to a region where the sludge 108 is settled, so that the sludge 108 can be easily sent to the region where the activated sludge is accommodated.

Seventh embodiment

The sewage treatment apparatus of the present example is a sewage treatment apparatus in which a manhole cover and an electrode are integrated. The sewage treatment apparatus of the present embodiment shown in FIG. 16 is the sewage treatment apparatus shown in FIG. 1, in which only the structures of the manhole cover 28 and the peripheral portions of the

electrodes

41 and 42 are changed. Therefore, the same components as those of the sewage treatment apparatus shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

As shown in fig. 16, the upper portion of the sewage treatment apparatus is covered with a plurality of manhole covers 28.The

electrodes

41 and 42 are attached to the manhole cover 28 through an insulator 400. Next, a state in which the

electrodes

41 and 42 are mounted on the insulator 400 will be described with reference to fig. 17.

In the sewage treatment apparatus of the present embodiment, the

electrodes

41 and 42 are attached to the manhole cover 28 through the insulator 400. Specifically, the

electrodes

41 and 42 are attached to the insulator 400 with screws or the like. The insulator 400 to which the

electrodes

41 and 42 are attached is attached to the manhole cover 28 with screws or the like. The

electrodes

41 and 42 are connected to a connection line 402, respectively, and are connected to the power supply device 38. Thus, the worker can take out the

electrodes

41, 41 to the ground by simply operating the handle 28A of the manhole cover 28 from the ground and removing the manhole cover 28 without entering the ground. That is, the maintenance of the

electrodes

41, 42 is much easier compared to the sewage treatment apparatus of the other embodiments.

In the sewage treatment apparatus of the present embodiment, the

electrodes

41 and 42 are immersed in the treatment water, but the insulator 400 is not immersed in the treatment water. Further, a connection wire having connectors at both ends is housed in the insulator 400, the connector at one end is connected to the power supply device 38, and the connector at the other end is connected to the electrode 41 or the electrode 42. Thus, the connection portions of the

electrodes

41, 42 and the power supply device 38 can be prevented from being immersed in the treatment water. That is, corrosion of the connection portion can be avoided.

In addition, as described in the present embodiment, when the

electrodes

41 and 42 are attached to the manhole cover 28, the positions of the

electrodes

41 and 42 in the sewage treatment apparatus may be higher than those inthe other embodiments. When the

electrodes

41 and 42 are positioned high, the

electrodes

41 and 42 are not immersed in the treatment water, and iron ions or aluminum ions are not supplied even when a voltage is applied to the

electrodes

41 and 42. Therefore, in the present embodiment, the voltage value between the

electrodes

41 and 42 is monitored by the detection unit 38A, and it can be determined whether or not the

electrodes

41 and 42 are immersed in the treatment water. In the sewage treatment apparatus of the present embodiment, it is preferable to provide a notification means for notifying that the voltage between the

electrodes

41 and 42 is a value when the

electrodes

41 and 42 are not immersed in the treated water.

Eighth embodiment

In the sewage treatment system shown in fig. 18, the same components as those in the sewage treatment system described in the first embodiment (see fig. 1) are denoted by the same reference numerals, and the description thereof will not be repeated. In fig. 19, some of the components shown in fig. 18 are omitted.

As shown in fig. 18 and 19, the sewage treatment system of the present embodiment is mainly constituted by a tank 200. The tank 200 is internally divided by a first partition wall 2, a second partition wall 3, a third partition wall 4 and a fourth partition wall 20 into a first anaerobic filter bed tank 5, a second anaerobic filter bed tank 10, a contact aeration tank 14, a settling tank 19 and a disinfection tank 21. In the tank 200 of this embodiment, the third transfer pipe 29 and the first pump 18 in the tank 1 shown in fig. 1 are not provided, but the lower end of the third partition wall 4 is separated from the bottom of the tank 200. Thus, the treated water decomposed in the contact aeration tank 14 in the tank 200 is supplied to the treated water tank 19.

The upper end of the first air dispersing pipe 16 is connected with a first blower 17. The lower end of the first air diffusing pipe 16 is provided so as to surround the inner side of the outer periphery of the bottom surface of the contact aeration tank 14 as described later (see fig. 19). A plurality of holes (holes 16 a: see fig. 19) are formed at the lower face side of the first air diffusing pipe 16. When air is fed from the first blower 17, the air is discharged from the holes as bubbles. Holes are formed at the lower side of the first air diffusing pipe 16, and sludge is less likely to enter the inside thereof than holes are formed at the upper or side thereof.

The contact aeration tank 14 is provided with a pump 133 at its lower portion. A sludge return line 134 is connected to the upper side of the pump 133, and a sludge return pipe 135 extending to the left side of the figure is connected to the upper end of the sludge return line 134. Thus, the sludge produced in the contact aeration tank 14 is sent to the first anaerobic filter bed tank 5.

In the tank 200 of FIG. 18, the settling tank 19 is connected to the first anaerobic filter bed tank 5 through the first return pipe 24. The first return pipe 24 is provided with a second air diffusing pipe 25 in the inside thereof. The second air diffusing pipe 25 is connected to a second blower 26, and forms a blowing hole for blowing air. The second air diffusing pipe 25 blows air supplied from the second blower 26 out of the blowing holes, and feeds the treated water in the settling tank 19 to the first anaerobic filter bed tank 5 through the first return pipe 24.

An electrolytic cell including a cassette 54 is provided above the contact aeration tank 14. Specifically, the box 54 is a hollow body formed by connecting 4 vertical plate bodies. The counter electrodes 51 and 52 are provided inside the case 54. The counter electrodes 51 and 52 are connected to a power supply 57. A third air diffusing pipe 53 is provided inside the case 54. The third air dispersing pipe 53 is connected to a fourth blower 56.

In the case 54, metal ions such as iron ions and aluminum ions are eluted by an electrolysis reaction (simply referred to as electrolysis) of the counter electrodes 51 and 52. Thus, in the contact aeration tank 14, the eluted metal ions react with the phosphorus compound in the treated water to produce a water-insoluble metal salt, which is then coagulated. An example of the reaction between the metal ion and the phosphorus compound is shown in the above formula (4).

Next, the structure of the counter electrode 51 will be described in detail with reference to fig. 20 and 21. Fig. 20 is a perspective view of the counter electrode 51. Fig. 21 is a partially cut-away perspective view of the counter electrode 51.

The counter electrode 51 includes two metal plates of the electrodes 711 and 712. The metal plate is made of, for example, iron or aluminum. The counter electrode 51 includes a support 710. A handle 710A is attached to an upper portion of the support 710. A cover 713 is attached to the left side surface of the support 710. Specifically, the cover 713 is attached to the left side surface of the support body 710 by forming 6 screw holes in the cover 713 and screwing predetermined screws into the screw holes. The electrode 711 is attached to the cover 713 with nuts 711A and 711B. The threaded holes include threaded

holes

713A, 713B (see fig. 22), 713C, 713D, 713E. The predetermined screws include

screws

717A, 717B, 717C, and 717D shown in fig. 22.

A guide 719D is attached to the upper rear portion of the support 710, and the wiring 719 extends upward from the guide 719D toward the support 710. The guide 719D is cylindrical, and the wire 719 passes through the inside of the guide 719D. One end of the wiring 719 is connected to a connector 719C.

The wiring 719 is embedded in the assembly of the support 710 and the cover 713 from the front (lower) portion of the guide 719D to the other end. The wiring 719 includes a plurality of wirings (including wiring 719A described later) therein. At the other end of the wiring 719, terminals such as a terminal 718 (see fig. 22) described later are mounted on each of the plurality of wires enclosed therein.

Fig. 22 and 23 are partially cut-away exploded perspective views showing a part of the counter electrode 51. In fig. 23, the wiring 719, the connector 719C, the wiring 719A, and the terminal 718 are not shown for clarity.

As shown in fig. 22 and 23,

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 jigs

715 and 716 are conductive members, and are preferably made of a material that is not easily corroded.

The electrode fixing jig 715 is a plate body formed with protrusions 715A and 715B. The protrusions 715A, 715B may penetrate holes formed in the cover 713. The electrode 711 is attached to the protrusions 715A and 715B via nuts 711A and 711B, and is electrically connected to the protrusions 715A and 715B.

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

When the electrode fixing jig 715 is attached to the cover 713 and the cover 713 is attached to the support 710, the terminal 718 is disposed at a position where it contacts the protrusion 715. Thus, the electrode 711 is electrically connected to the terminal 718 through the protrusion 715A.

The electrode fixing jig 716 also has protrusions similar to the protrusions 715A and 715B. The protruding portion protrudes from the left side surface of the support body 710. Further, a terminal different from the terminal 718 is provided between the electrode fixing jig 715 and the electrode fixing jig 716 slightly in front of the center of the support body 710. The other terminal described here constitutes an end of a wire other than the wire 719A among the plurality of wires included in the wire 719. The other terminal is electrically connected to a protrusion formed on the electrode fixing jig 716, and the protrusion is connected to the electrode 712. Thus, the other terminal is electrically connected to the electrode 712.

An insulator (not shown) is provided between the electrode fixing jig 715 and the electrode fixing jig 716, and between the terminal and the terminal 718. Thus, the electrode 711 and the electrode 712 can be surely prevented from being short-circuited in the assembly of the support 710 and the cover 713.

The electrode fixing clamp 715 is screwed to the housing 713 by

screws

714A, 714B, and 714C. The electrode fixing jig 716 is screwed to the support body 710 by

screws

714D, 714E, and 714F.

A gasket 710B is provided between the support 710 and the cover 713 outside the position where the cover 713 is screwed. A gasket 710C is provided between the support 710 and the electrode fixing jig 716, outside the position where the electrode fixing jig 716 is screwed. Further, a gasket similar to the gasket 710C is provided between the cover 713 and the electrode fixing jig 715 outside the position where the electrode fixing jig 715 is screwed.

Thus, when the support 710 and the cover 713 are combined, the terminals 718 and the other terminals are housed in the support 710 and the cover 713 without water entering the inside.

Ninth embodiment

FIG. 24A is a left side view of the electrodes and the members disposed around the electrodes in the electrolysis cell of the ninth embodiment. Fig. 24B is a plan view of the respective components.

The upper end of the electrode 260 is mounted on the support 261. A pressing plate 263 is provided inside the support 261, and the pressing plate 263 presses the front and rear of the upper end of the electrode 260.

Terminals

267, 268 are embedded in the pressing plate 263.

A handle 262 is attached to an upper portion of the support 261.

One end of the wiring 278 is connected to a predetermined power supply. The wiring 278 is incorporated in the handle 262, the support 261, and the pressing plate 263. The other end of the wire 278 is connected to the terminal 267. The electrode 260 is electrically connected to the terminal 267 inside the support 261, and thus the electrode 260 is electrically connected to the predetermined power supply.

A gasket 264 is provided between the support 261 and the electrode 260, and the gasket 264 is in contact with the lower end of the pressure plate 263. The gasket 264 covers the outer periphery of the electrode 260. In this way, ingress of contaminated water into the interior of the support 261, i.e. the space in which the

terminals

267, 268 are located, is avoided.

An air diffuser 271 is provided so as to cover the left, lower, and right sides of the electrode 260. The end of the air-dispersing pipe 271 is U-shaped, and the left upper end thereof is connected to the pump 256. A cover 277 is attached to the upper right end of the air-dispersing pipe 271.

A plurality of holes 271A are formed under the air-dispersing pipe 271. Thus, when air is supplied from the fourth blower 56, the air-diffusing pipe 271 discharges air bubbles from the hole 271A. When power is supplied to the electrode 260, or another electrode for electrolysis, the bubbles remove the film formed on the surface of the electrode 260. The air-dispersing pipe 271 is also fixed to the support body 261.

Fixing members 272 to 276 for fixing the electrode 260 to the air-diffusing pipe 271 are attached to the air-diffusing pipe 271.

FIG. 25 is a schematic view of an electrolytic cell in this example. As shown in fig. 25, the air dispersing pipe 271 is connected to the fourth blower 256 through a pipe connector 361 and an air supply pipe 360. In this embodiment, the air dispersing pipe 271 is detachable from the fourth blower 256 by rotating the pipe connector 361.

In the electrolysis unit of this embodiment, since the air-diffusing pipe 271 can be detached from the fourth blower 256, the air-diffusing pipe 271 can be cleaned. Thus, it is possible to avoid that a sufficient amount of bubbles cannot be discharged from the hole 271A due to the hole 271A being clogged with sludge. Therefore, in this embodiment, the removal of the surface film of the electrode 260 is not affected by the clogging of the hole 271A.

The electrode 260 is immersed in the treatment water W in the electrolytic bath 270. Further, a mechanism (not shown) for discharging the precipitates generated by the electrolysis of the electrodes 260 and the like out of the electrolytic bath 270 is provided in the electrolytic bath 270.

Fixing tools 270A and 270B for fixing the support 261 to the electrolytic cell 270 are attached to the electrolytic cell 270. In the present invention, the air-diffusing pipe 271 need only be detachable from the blower 256 (may be detachably attached), and the air-diffusing pipe 271 need not necessarily be fixed to the support 261.

Next, a state in which the electrode 260 is mounted on the support 261 will be described with reference to fig. 26. Fig. 26 partially shows the left side of each member shown in fig. 24A and 24B. The electrode 260 is fitted into the support body 261 and the air-diffusing pipe 271 from the rear and attached to a position shown by a chain line P. The electrode 260 is fixed to the support body with a predetermined screw or the like.

Holes

260A and 261A for inserting the screws are formed in the electrode 260 and the support 261, respectively.

In the above-described embodiment, 1 electrode is supported by the support 261. The electrolysis reaction is usually caused by two electrodes. Therefore, it is also considered to support two electrodes with 1 support 261. Fig. 27A and 27B show, as a modification of the present embodiment, the electrodes in the electrolysis cell and the members arranged around the electrodes when the support 261 supports two electrodes. Fig. 27A is a left side view of these components, and fig. 27B is a plan view of these components.

Electrodes 260 and 160 are mounted on support 261. The support 261 is provided with a pressing plate 363 for pressing the front and rear of the upper end of the electrode 360, in addition to the components shown in fig. 24A and 24B. Terminals (including a terminal 368) corresponding to the

terminals

267 and 268 are housed in the pressure plate 363. The terminals electrically connect the electrodes 360 to the wiring 378. Further, a handle 262 is attached to an upper portion of the support 261. The depth of the support 261 and the handle 262 is about twice as large as that of the support shown in fig. 24A and 24B.

An insulator 300 is fitted into the depth direction intermediate portions of the support 261 and the handle 262. Thus, electrical connection between the

terminals

267, 268 and the terminal connected to the electrode360 can be prevented. In addition, one end of the wiring 378 is connected to a predetermined power source. The insulator 300 is fixed by a screw 311 embedded in the handle 262.

A packing 364 (corresponding to the packing 264) is provided to be connected to the lower end of the pressure plate 363. The gasket 364 partially covers the outer circumference of the electrode 360. This prevents the entry of contaminated water into the interior of the support 261, i.e., into the space where the terminal connected to the electrode 360 is located.

The air diffuser tube 371 covers the left, lower and right sides of the electrode 360. The air diffuser tube 371 is connected to the pump 256. The air diffuser tube 371 has a plurality of holes formed in the lower surface thereof, and is detachable from the pump 256, similarly to the air diffuser tube 271. Further, the air diffuser 371 is also provided with members (including fixing members 372 to 374) for fixing the electrode 360, similarly to the air diffuser 271.

In the electrolysis unit of this embodiment, the entire electrolytic bath 270 is immersed in the water in the first anaerobic filter bed tank 5, the second anaerobic filter bed tank 10, the contact aeration tank 14, or the precipitation tank 19 in the tank 1 shown in fig. 1 or fig. 18, and the metal ions are supplied to the sewage in each tank.

The above embodiments are illustrative in all respects and not restrictive. Any equivalent variations within the scope of protection are within the scope of the invention.

Claims

1. A sewage treatment apparatus installed underground for treating sewage, comprising a sewage treatment section (5) for storing sewage and an ion supply section (37) for supplying iron ions or aluminum ions to the sewage treatment section (5), wherein the ion supply section (37) is provided with electrodes (41, 42) attached to a manhole cover.

2. The sewage treatment apparatus according to claim 1, further comprising a detecting means (38A) for detecting whether or not the electrodes (41, 42) are immersed in the treatment water.

3. A sewage treatment device comprising an electrode (711) which is electrolyzed by supplying electric power from a predetermined power supply to the electrode (711); characterized by also comprising

Electrode support members (710, 713) for supporting the electrode (711);

a wiring (719) for connecting the electrode (711) and the predetermined power supply;

a terminal (718) provided at the end of the electrode side of the wiring (719);

a connecting member (715) which is attached to the electrode support member, is detachable from the electrode support member, and electrically connects the terminal and the electrode;

the terminal 718 is incorporated in the electrode support member 710, 713 and does not contact the outside of the electrode support member 710, 713.

4. The sewage treatment apparatus according to claim 3, wherein at least a part of the wiring (719) is incorporated in the electrode supporting member (710, 713).

5. The wastewater treatment apparatus according to claim 3 or 4, wherein said electrode support member (261, 262) supports a plurality of electrodes (260, 360), and an insulator (300) is provided between 1 of said plurality of electrodes and another electrode.

6. A sewage treatment apparatus comprising an electrode (260) for electrolyzing the electrode, characterized by further comprising a tube (271), wherein a hole (271A) is formed in the tube (271), the tube is detachably connected to a predetermined pump, and bubbles are discharged to the vicinity of the electrode through the hole.

7. The sewage treatment apparatus according to claim 6, further comprising electrode support members (261, 262) for supporting said electrodes (260) and said pipes (271).

8. The wastewater treatment apparatus according to claim 6 or 7, wherein the electrode (260) is electrolyzed when supplied with electric power from a predetermined power source; also comprises

A wiring (278) for connecting the predetermined power source to the electrode (260);

electrode supporting members (261, 262) for supporting the electrodes;

the electrode support member has at least a part of the wiring incorporated therein.

9. The wastewater treatment apparatus according to any of claims 1 to 8, further comprising

Anaerobic tanks (5, 10) for introducing sewage and containing anaerobic microorganisms;

an aerobic tank (14) into which sewage is introduced and in which aerobic microorganisms are present;

a settling tank (19) for introducing sewage and settling sludge;

the electrode (260) is immersed in the sewage in the anaerobic tank, the aerobic tank, or the precipitation tank.

10. The wastewater treatment apparatus according to any of claims 1 to 8, further comprising an electrolytic bath (270) for electrolyzing said electrode (260) by introducing only wastewater, wherein said electrode is immersed in wastewater in said electrolytic bath.