JPH057397U - Contact aeration sewage treatment equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To enable efficient removal of BOD and phosphorus with a single contact aeration tank. [Constitution] BOD of relatively large area in contact aeration tank
The BOD is removed by passing a downward flow of 2 to 3 cm / sec through the metal contact material, and 10 to 20 is applied to the iron contact material having a relatively small area
Phosphorus is removed through an upflow of cm / sec.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to a contact aeration sewage treatment device for a septic tank, and in particular, a ferrous material is used for a flow path between contact materials. The present invention relates to a contact aeration sewage treatment device in which the

[0002]

[Prior art]

  In the contact aeration tank of the septic tank, the treatment liquid (sewage) in it is repeatedly contacted with the contact material. Then, the processing liquid is purified.

[0003]   As shown in FIG. 5, the contact materials 3 are arranged in the contact aeration tank 1, and the contact aeration is seen in a cross section. A flow path 5 is provided between the contact materials 3 so that an upward flow of the processing liquid is formed in the approximate center of the tank 1. Kick

[0004]   An air supply pipe 11 is arranged in the flow path 5, and an air diffusion pipe 13 connected to the lower part of the air supply pipe 11 Air is discharged from the (diffuser) to generate an upward flow in the processing liquid, and the processing liquid is circulated. Make a ring.

[0005]   The processing liquid that has risen in the flow path is dispersed from the upper end of the flow path 5 to the surface of the contact material 3 and contacted. It descends through the material. The processing liquid descending through between the contact materials is the lower end portion of the contact material 3. Exits, is drawn to the diffuser 13, and is re-engaged in the updraft. . In this way, a circulating flow repeatedly passing between the contact materials is formed in the contact aeration tank 1, The BOD in the treated water is removed by the microbial film formed on the surface of No. 3.

[0006]   The flow velocity of the downward flow passing between the contact materials was approximately 2 to 3 cm / sec. On the other hand, phosphorus in wastewater using electrochemical iron corrosion by oxygen concentration battery on iron surface Removal (JP-A 61-268397, JP-A 62-250997, JP-A 1-38) 197) was developed and the stirring flow velocity on the surface of the iron contact material was set within the range of 10 to 20 cm / sec. Is recommended for maintaining electrochemical iron corrosion by oxygen concentration batteries. (JP-A 1-218683). When phosphorus is removed by iron contact material, treated water is The iron contact material is arranged so as to descend the iron contact material (Japanese Patent Laid-Open No. 63-31598). , JP 62-10099, and JP 61-178092). The rising flow of treated water is It is made in a separate flow path by an air diffuser or the like.

[0007]   In addition, for biological denitrification method using suspended microorganisms (activated sludge) and utilization of iron contact material Simultaneous Removal of Nitrogen and Phosphorus Combined with the Dephosphorization Method No. 12, pp. 25-33) was developed, the denitrification rate was improved when iron contact materials were used. It is also said that the settling property of activated sludge is improved.

[0008]

[Problems to be solved by the device]

  However, in general, after removing BOD, phosphorus removal and denitrification are performed, and In order to operate the plant efficiently and functionally, the microorganisms in the contact aeration sewage treatment equipment Functional combination of BOD removal treatment with membrane and dephosphorization treatment with iron placed in the flow path There is no suggestion in the prior art to do so.

[0009]   In addition, the surface of the iron material easily forms an electrochemical passivation region depending on the water quality conditions. Therefore, the elution of iron ions from the iron material may be substantially stopped. There are drawbacks. Furthermore, even if sludge adheres to the iron material surface, elution of iron ions is prevented. .

[0010]   Therefore, the purpose of the present invention is to perform a BOD removal treatment by a microbial film attached to the contact material. A contact aeration sewage treatment device that can functionally perform dephosphorization treatment with iron material installed in the flow path Is to provide.

[0011]   Further, an object of the present invention is to stably elute iron ions from the iron material arranged in the flow path. A contact aeration sewage treatment apparatus is provided.

[0012]

[Means for Solving the Problems]   The contact aeration sewage treatment apparatus of the present invention comprises a contact aeration tank for containing a treatment liquid and the contact aeration. Circulating flow that creates a circulating flow of the processing liquid in the contact aeration tank with the contact material placed in the tank Contact exposure having a generator and a flow path for forming the circulating flow together with a contact material In the gas treatment device, an iron material is arranged in the flow passage, and the flow velocity of the treatment liquid in the flow passage is It is characterized in that it is set to 10 to 20 cm / sec.

[0013]   The flow path can be formed vertically or horizontally. And the circulating flow generator is , An aerator, an air diffuser, a stirrer, or a rotor.

[0014]

[Action]

  The contact aeration sewage treatment device of the present invention uses the circulating flow of the treatment liquid in the contact aeration tank. By utilizing it, electrochemical iron corrosion by the oxygen concentration battery is generated on the surface of the iron material arranged in the flow path. In order to maintain a suitable corrosion state while preventing the iron ions from being excessively eluted The required treatment liquid flow rate within the range of 10 to 20 cm / sec is obtained, and the microbial membrane is The adhered contact material can obtain a reaction surface with a relatively low flow rate for BOD removal. . The treatment liquid flow rate is used to expand or reduce the flow passage area of the circulation flow or to generate the circulation flow. It can be controlled by adjusting the air diffuser, stirring device or rotor.

[0015]

【Example】

  FIG. 1 shows a contact aeration tank 1 of an embodiment to which the present invention is applied. Exposure to the contact aeration tank 1 The processing liquid to be gas-processed flows in, and the contact material (filter material and Arranged so that the flow path 5 is formed in the central part of the contact aeration tank 1 when viewed in cross section. Has been done. The contact material 3 generally has a plate shape, a granular shape, a lump shape, or a honeycomb shape. It is arranged in a body shape.

[0016]   The flow path 5 is separated from the contact material 3 by the support wall 7 of the contact material 3 and It extends along a groove. An aerator 19 is arranged above the flow path 5.

[0017]   An aerator 19 is arranged above the flow path 5 to raise the processing liquid in the flow path 5. At the same time, air is mixed into the processing liquid that has risen in the flow path 5, and the processing liquid is placed on the contact material 3. Disperse.

[0018]   Further, in this embodiment, the iron material 15 is arranged in the flow path 5. Iron material 15 Any substance that is corroded by physical fluid and releases iron ions Good. However, an iron material such as mild steel, which is easily corroded, is preferable, and gray iron or the like can also be used. Further, the shape of the iron material 15 is not limited as long as it does not significantly impede the flow of the processing liquid. It may be one. For example, steel plates, steel frames, steel pipes, reinforcing bars, scrap iron, cutting chips, lathe scraps, and staples. Either can be used. Arrange the iron material 15 so that it is in wide contact with the flow of the processing liquid. It can have any shape if it exists. For example, by fixing an iron material in a cylindrical member, the flow path 5 In the car, scrap iron such as steel cans are stored in the car member, Attached or fixed one is inserted into the flow path 5, or thin plates or iron pipes are assembled to form the flow path. 5 may be provided. However, the iron material 15 is removable for cleaning the flow path 5. It is desirable to put it.

[0019]   In the operation of this embodiment, the treatment liquid is put in the contact aeration tank 1 and the aerator 19 is used. When the operation is performed, the processing liquid is distributed by the aerator 19. Was distributed The treatment liquid is dispersed on the surface of the contact material 3 and descends through the space between the contact materials 3. Also, The processing liquid in the passage 5 rises, and an ascending flow occurs in the passage. Descended through contact material 3 The treatment liquid is discharged from the lower end portion of the contact material 3 and is re-engaged in the upward flow in the flow path 5. . In this way, a circulating flow that repeatedly passes between the flow path and the contact material is generated in the contact aeration tank 1. Wear.

[0020]   In this embodiment, this circulating flow is used for wastewater treatment without waste. I.e. processing When the liquid descends between the contact materials, the surface of the contact material 3 to which the microbial film is attached is activated. Biological BOD removal using sludge is performed. The descending flow velocity of the processing liquid between the contact materials is 2-3 cm / sec. On the other hand, when the processing liquid rises in the flow path 5 in which the iron material is arranged In addition, the iron ions eluted due to the corrosion of the iron material surface combine with the phosphate ions in the wastewater, It becomes a sparingly soluble iron phosphate, and phosphorus is removed. At this time, the surface of the iron material 15 The stirring flow rate, that is, the flow rate of the processing liquid in the channel 5 is set within the range of 10 to 20 cm / sec. And then deposited on the surface of the iron material 15 by the reaction of iron ions with phosphoric acid in the wastewater. Passivation that promotes delamination of soft mud-like adhered coatings and reduces the corrosion rate of iron The DO concentration is adjusted so as not to enter the range. The flow rate of this processing liquid is The cross-sectional area of the contact member 3 and the cross-sectional area of the contact member 3 are roughly determined by the ratio. It is precisely controlled by the supply of air.

[0021]   When the support wall 7 is made of iron, electrochemical iron corrosion occurs on the surface of the support wall 7, It goes without saying that iron ions are eluted. Therefore, insert the iron material 15 into the flow path 5. Even if it does not exist, phosphorus can be removed using the iron support wall 7. But the support wall 7 It is not preferable to elute such a structure because it affects the life of the structure.

[0022]   BOD removal by the contact material 3 is generally performed under aerobic conditions, but contact aeration By intermittently keeping the tank 1 anaerobic, BOD removal is limited. However, it is possible to make conditions suitable for denitrification by suspended microorganisms.

[0023]   FIG. 2 shows a contact aeration tank 1 of another embodiment to which the present invention is applied. In this embodiment, An air diffuser 9 is arranged in the flow path 5 instead of the aerator 19 in the embodiment of FIG. Has been done.

[0024]   The air diffuser 9 includes an air supply pipe 11 extending vertically in the flow path 5, and a lower end of the air supply pipe 11. And an air diffuser 13 extending laterally. Air diffuser A large number of holes are formed in 13 so that air can be discharged from there.

[0025]   During the operation of this embodiment, the treatment liquid is put in the contact aeration tank 1 and the diffusing pipe 13 is emptied. Supply the energy. Then, the air discharged from the air diffuser 13 rises in the flow path 5, An upward flow of the processing liquid is generated by the so-called air lift effect. Going up in the channel 5 The treated liquid is dispersed from the upper end of the flow path 5 to the surface of the contact material 3 and descends between the contact materials. It The processing liquid descending through between the contact materials comes out from the lower end portion of the contact material 3, and the diffusing pipe 1 It is brought to the place of 3 and is again involved in the upflow. Thus, contact aeration tank 1 A circulating flow that repeatedly passes between the flow path and the contact material is formed therein. BO by this circulating flow D removal and the like are the same as in the first embodiment.

[0026]   In FIG. 3, the air supply pipe 11 of the air diffuser 9 is different from the center of the aeration tank of the first embodiment, unlike the aeration tank. 1 shows an embodiment in which the air diffuser 13 is arranged near the wall of the No. 1 and the air diffuser 13 is arranged below the contact member 3. In the present embodiment, the treatment liquid rises in the contact material 3 and descends in the flow path 5, and thus the descending flow. Contacts the iron material 15. The operation of this embodiment is essentially the same as that of the embodiment of FIGS. Is done in the same way.

[0027]   FIG. 4 shows an oxidation ditch 21 to which the present invention is applied as an example. Oxy An iron material 31 is arranged on a part of the foundation ditch 21. The processing liquid is the rotor At 27, oxygen is supplied and a circulating stream is formed.

[0028]   In this example, the flow rate of the processing liquid in the ditch was compared with an average of around 30 cm / sec. Since it is relatively large, the iron material arrangement portion 25 is used as the enlarged flow path 29, and the flow velocity in this area is set to 10 The efficiency of phosphorus removal by the iron material 31 is maintained by dropping it to a range of -20 cm / sec.

[0029]   The operation of this embodiment is performed essentially in the same manner as the embodiment of FIGS.

[0030]

[Effect of device]

  Since the present invention is configured as described above, the treatment in the existing contact aeration tank is performed. BOD in sewage is attached to the microbial membrane at a relatively low flow rate by utilizing the circulation flow of the physical fluid. The phosphorus in the sewage removed by the contact material layer was placed in the flow path with a relatively high flow velocity. It is removed by combining with iron ions eluted by corrosion of the material, and it is functional and In addition, the treatment with the microbial membrane and the treatment with the iron material can be performed. Also, BO in a single tank Since D removal and phosphorus removal are performed, the installation area of the device can be narrowed.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an embodiment of a contact aeration tank to which the present invention is applied.

FIG. 2 is a schematic vertical sectional view of another embodiment of the contact aeration tank to which the present invention is applied.

FIG. 3 is a schematic vertical sectional view of another embodiment of the contact aeration tank to which the present invention is applied.

FIG. 4 is a schematic vertical sectional view of another embodiment of the contact aeration tank to which the present invention is applied.

FIG. 5 is a schematic vertical sectional view of a conventional contact aeration tank.

[Explanation of symbols]

1 Contact aeration tank 3 contact materials 5 channels 9 Air diffuser 11 Air pipe 13 Air diffuser (diffuser) 15 Iron material 19 aerator 21 Oxidation Ditch 23 Precipitation part 25 Contact material 29 Expansion channel 31 Iron

Claims (3)

[Scope of utility model registration request] 1. A contact aeration tank for containing a treatment liquid, a contact material arranged in the contact aeration tank, a circulation flow generator for generating a circulation flow of the treatment liquid in the contact aeration tank, and the contact material together with the contact material. In a contact aeration processing apparatus having a flow path for forming a circulating flow, an iron material is arranged in the flow path, and the flow rate of the processing liquid in the flow path is 10 to 20 cm / sec. Characteristic contact aeration sewage treatment equipment. 2. The flow passage is vertical, and the circulation flow generation device for generating an upward flow in the flow passage is an aerator, a circulation device or an air diffuser arranged above or below the flow passage. The contact aeration sewage treatment apparatus according to claim 2. 3. The contact aeration sewage treatment apparatus according to claim 1, wherein the flow passage is horizontal and the treatment liquid is formed so as to flow laterally in the flow passage.