WO2004048282A1

WO2004048282A1 - Biological treatment method and biological treatment device

Info

Publication number: WO2004048282A1
Application number: PCT/JP2003/015156
Authority: WO
Inventors: Yuichi Fuchu; Hiroshi Sakuma; Noriko Ikeda; Hitomi Suzuki
Original assignee: Ebara Corporation
Priority date: 2002-11-27
Filing date: 2003-11-27
Publication date: 2004-06-10
Also published as: AU2003284461A1

Abstract

A biological treatment method and a biological treatment device, the method comprising the steps of vertically moving a cloth-like material (8) in a water tank (2) for treating sewage (1) to perform the agitation and biological treatment of the sewage (1). A part of the cloth-like material (8) is led into the air to supply oxygen into the water tank (2), the biological treatment of the sewage (1) is performed by using a sheet-like three-dimensional network structure (27), the agitation and biological treatment of the sewage (1) are performed by vertically moving the three-dimensional network structure (27) in the sewage (1), a part of the three-dimensional network structure (27) is continuously or intermittently led into the air, the air taken in the three-dimensional network structure (27) is temporarily discharged into the sewage (1) and/or the sewage (1) taken in the three-dimensional network structure (27) is discharged into the air. The biological treatment device comprises the water tank (2) for treating the sewage (1) and the cloth-like material (8) installed so as to vertically move in the water tank (2).

Description

Description Biological treatment method and biological treatment equipment Technical field

The present invention relates to a biological treatment method and a biological treatment device for treating sewage, and in particular, to transfer sewage such as sewage, organic wastewater, inorganic wastewater containing nitrogen, highly polluted river water, and lake water. Use biofilm floor! / The present invention relates to a biological treatment method and a biological treatment device for treating. Background art

As a method of biologically treating organic wastewater, a method called a rotating disk method is known. With the rotating disk method, multiple disks are rotated while the lower half is immersed in wastewater to form a biofilm on the surface of the disk, and the organisms in the wastewater are decomposed in the presence of oxygen Things. This method enables simultaneous agitation of wastewater as a liquid to be treated and biofilm treatment, and is a technology that has been widely used in Japan since about 30 years ago.

On the other hand, the most widespread method is the activated sludge method. The reaction tank used for this activated sludge method is also called an aeration tank. In the activated sludge method, biological treatment is generally performed by diffusing air into the sewage to agitate and supply oxygen to the sewage to promote metabolism of the activated sludge. The conventional activated sludge method is a method called a standard method, which mainly removes BOD (Biochemical Oxygen Demand) and SS (Suspended solid). However, in recent years, the necessity of removing eutrophic salts has increased, and a method called advanced treatment has been used to remove nitrogen and phosphorus in addition to BOD and SS. In the case of the standard method, the biological reaction time is generally 6 to 8 hours, but in the case of the advanced treatment method, the biological reaction time is about twice as long as that of the standard method. In this case, it is common to add a reaction tank to shorten the processing time, but if there is no site area, a microorganism-adhered carrier may be charged into the reaction tank.

In the rotating disk method, the biofilm is too thick on the disk, causing torque overrun. In some cases, the space between the discs is buried with microorganisms, and proper agitation cannot be achieved. Furthermore, if a rotating disk is to be attached to an existing reactor, the depth of the reactor cannot be fully utilized, which is not reasonable.

On the other hand, the activated sludge method poses a problem especially when the function is upgraded from the standard method to the advanced treatment method. Adding more reactors not only requires a lot of land area, but also has the disadvantage of huge construction costs. In addition, in the method of charging the microorganism-adhering carrier, the microorganism-adhering carrier must be flowed through the entire reaction tank, and the outflow of the microorganism-adhering carrier from the reaction tank must be prevented. For this purpose, it is indispensable to pay careful attention to equipment, such as appropriately combining a stirrer and a screen (filter). Disclosure of the invention

The present invention has been made in view of the above conventional technology, and can drastically solve the clogging of the conventional rotating disk method, and can effectively use the existing reaction tank as it is, and It is an object of the present invention to provide a biological treatment method and a biological treatment device capable of performing a stable treatment without installing a special stirrer and a screen when the function is upgraded from the conventional method to the advanced treatment method.

In order to solve the above-described problems, one embodiment of the present invention is a biological treatment method characterized by moving a cloth material up and down in a water tank for treating wastewater to perform agitation and biological treatment of the wastewater. is there.

In a preferred aspect of the present invention, a part of the cloth material is led into the air, whereby oxygen is supplied into the water tank.

Another embodiment of the present invention is a biological treatment apparatus including: a water tank for treating sewage; and a cloth-like material provided to move up and down in the water tank.

Another embodiment of the present invention is a biological treatment method for biologically treating wastewater, wherein the biological treatment is performed using a sheet-like three-dimensional network structure.

Another embodiment of the present invention is a biological treatment method for biologically treating sewage, wherein a sheet-like three-dimensional network structure is moved up and down in the sewage to perform sewage agitation and biological treatment. Biological treatment method.

In a preferred aspect of the present invention, a part of the three-dimensional network structure is continuously or intermittently formed. It is characterized by being guided into the air.

In a preferred aspect of the present invention, the air taken into the three-dimensional network structure is discharged in sewage.

In a preferred aspect of the present invention, the wastewater taken into the three-dimensional network structure is discharged in the air.

Another embodiment of the present invention is a biological treatment apparatus including a water tank for treating sewage, and a sheet-like three-dimensional mesh structure installed to move up and down in the water tank. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram showing a biological treatment apparatus according to a first embodiment of the present invention.

FIG. 2A is a schematic plan view showing the biological treatment apparatus used in Example 1.

FIG. 2B is a schematic front view of the biological treatment apparatus shown in FIG. 2A.

FIG. 2C is a sectional view taken along the line II-II of FIG. 2A.

FIG. 3A is a schematic plan view showing the biological treatment apparatus used in Example 2.

FIG. 3B is a schematic front view of the biological treatment apparatus shown in FIG. 3A.

FIG. 4 is a schematic diagram showing a biological treatment apparatus according to a second embodiment of the present invention.

FIG. 5 is a partially enlarged view showing a three-dimensional network structure incorporated in the biological treatment apparatus shown in FIG.

6A to 6C are configuration diagrams showing processed products of the three-dimensional network structure.

FIG. 7 is a perspective view showing a moving mechanism of the three-dimensional network structure.

8A and 8B are partial enlarged views for explaining the attachment of the three-dimensional network structure of FIG. 7 to a roller.

FIG. 8C is a side view showing the three-dimensional network structure attached to the roller.

FIG. 9 is a schematic view showing another example of the biological treatment device according to the second embodiment of the present invention.

FIG. 10 is a schematic view showing another example of the moving mechanism to which the three-dimensional network structure is attached. FIG. 11A is a schematic plan view showing the biological treatment apparatus used in the third embodiment.

FIG. 11B is a schematic front view showing the biological treatment apparatus shown in FIG. 11A.

FIG. 11A is a cross-sectional view taken along line XI-XI of FIG. 11A. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a biological treatment apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a biological treatment apparatus according to a first embodiment of the present invention. In FIG. 1, raw water 1 as sewage (water to be treated) is introduced into a biological reaction tank (water tank) 2. The sludge 4 settled in the sedimentation tank 3 returns to the biological reaction tank 2 as return sludge 5, and the activated sludge 6 is present in the biological reaction tank 2. Activated sludge 6 consisting of returned sludge 5 can be omitted if necessary. Further, rollers 7a and 7b and a biofilm bed (cloth material) 8 are attached to the biological reaction tank 2 as shown in the drawing. That is, the rollers 7a and 7b are arranged parallel to each other, one roller 7a is located in the air, and the other roller 7b is located in the liquid (raw water 1). The biofilm bed 8 is attached to rollers 7a and 7b, and the biofilm bed 8 moves up and down according to the rotation of the rollers 7a and 7b. The biofilm bed 8 is preferably a cloth material such as a woven fabric or a nonwoven fabric, which is resistant to water and is resistant to bending, and may be a fabric material processed so that a biofilm is easily attached thereto. As a processing method of the cloth material, the weaving method of the cloth material itself may be devised, and long hair may be planted on the cloth material, or a contact material used in a contact oxidation device may be planted. .

The nonwoven fabric may be a synthetic fiber such as vinylon, polyester, rayon, or polypropylene, and in some cases, a glass fiber, and is not particularly limited.

As the woven fabric, a nonwoven fabric such as synthetic fibers such as polypropylene, polyester, nylon, and polyvinylidene chloride is suitable. However, woven fabrics are not limited to this. If the biofilm bed has water absorption, not only is the power required to move the biofilm bed excessively necessary, but it also causes the biofilm bed to extend and drip, which is undesirable.

When the biofilm bed 8 moves up and down, a biofilm is formed on the surface of the biofilm bed 8. In addition, when the biofilm bed 8 moves in the vertical direction, oxygen in the atmosphere can be taken into the liquid in the biological reaction tank 2 when the biofilm bed 8 is submerged in the liquid from an air state. Even after submersion in the liquid, the liquid itself can be stirred by moving the biofilm bed 8, and activated sludge 6 and biological Since the microorganisms separated from the membrane bed 8 can be sufficiently mixed, they can be guided to the sedimentation tank 3 without sedimentation in the biological reaction tank 2. In this way, biofilm treatment (biological treatment) is performed.

The excessive adhesion of the biofilm, which has been a problem with the rotating disk method, is a problem because the excessively attached biofilm is peeled off by the deflection of the biofilm bed 8 between the rollers 7a and 7b. Hateful. When the biofilm is firmly attached to the biofilm bed 8, a scraping mechanism 12 for scraping the biofilm from the biofilm bed 8 may be provided. If you do not want to dissolve oxygen in the liquid as in the case of an anaerobic tank or anoxic tank, all rollers 7a and 7b may be submerged.

Hereinafter, the present invention will be described specifically with reference to examples.

[Example 1]: Example of BOD-SS removal

2A to 2C show an example of the biological treatment apparatus used in the first embodiment. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is a cross-sectional view taken along the line II-II of FIG. 2A. In this example, two sets of biofilm bed moving units 9 are used. As shown in FIG. 2C, the biofilm bed transfer hood 9 includes a plurality of rollers 7a located in the air and a plurality of rollers 7b located in the liquid. The roller 7b is connected by a single biofilm bed 8.

The biofilm bed moving unit 9 has a configuration in which one biofilm bed 8 and a plurality of rollers 7a and 7b are combined, but a pair of rollers 7a and 7b as shown in FIG. A plurality of mechanisms each having one biofilm bed 8 attached thereto may be combined. In this case, if the upper rollers 7a are connected to each other by a chain or the like, these rollers 7a can be driven by one drive source, which is economical.

As a method of arranging the biofilm bed moving unit 9, it is desirable that the flow direction of the raw water 1 and the biofilm bed 8 (the extending direction of the rollers 7a and 7b) be parallel. If both are in a vertical positional relationship, a short circuit flow is likely to occur in the biological reaction tank 2. Even in the case of a parallel positional relationship, short-circuit flow can be prevented by providing the partition wall 10 extending perpendicular to the flow direction of the raw water 1. In this case, it is preferable that the partition walls 10 are arranged on both sides of the biofilm bed moving unit 9 and before and after the biological unit unit 9.

In the embodiment shown in FIGS. 2A to 2C, air is diffused by a diffuser such as a blower. At least, by installing a sedimentation tank (not shown) downstream of the biofilm bed transfer unit 9, the BOD.280 mg / L and SS65 mg / L can be reduced by 2O for both BOD and SS. mg / L or less.

[Example 2]: Example of updating from standard method to advanced treatment method

FIGS. 3A and 3B show an example of the apparatus used in the second embodiment. FIG. 3A is a plan view, and FIG. 3B is a front view. Raw water 1 is led to the anaerobic tank 2a. In the anaerobic tank 2a, a biofilm bed moving unit 9a is placed in a submerged state. The returned sludge 5 also flows into the anaerobic tank 2a, and the phosphorus contained in the returned sludge (activated sludge) 5 is discharged into the raw water 1. Here, in some cases, the biofilm bed transfer unit 9a may not be installed, and only a stirrer (not shown) may be installed so that the returned sludge 5 does not settle. Next, the raw water 1 is guided to the oxygen-free tank 2b. Here, the biofilm bed moving unit 9b is also placed in the water. The nitric acid tank 2c is disposed downstream of the oxygen-free tank 2b, and the nitric acid 11 is supplied from the nitric acid tank 2c to the oxygen-free tank 2b. Similar to the anaerobic tank 2a, the biofilm bed transfer unit 9b may not be installed in the anoxic tank 2b, and a stirrer may be installed in the anoxic tank 2b so that the returned sludge 5 does not settle.

In the next nitric acid tank 2c, a part of the biofilm bed 8 (see Figure 2C) must be in contact with air in order to achieve aerobic conditions. Furthermore, the biofilm bed 8 of the biofilm bed transfer unit 9d has a larger contact portion with air than the biofilm bed transfer unit 9c. If the contact area with air is large, such as the biofilm bed transfer unit 9d, the nitrifying bacteria attached to the biofilm bed 8 will be left under aerobic conditions for a long time, and nitrification will occur efficiently. . The amount of BOD oxidizing bacteria attached is large in the first stage of the nitric acid tank 2c, and the ratio of nitrifying bacteria increases in the second stage. In other words, it is reasonable to increase the portion of the biofilm bed 8 that comes into contact with the air in the latter stage compared to the former stage of the nitric acid tank 2c. Also, by increasing the rotation speed of the rollers 7a and 7b after the nitric acid tank 2c compared with the rotation speed of the rollers 7a and 7b before the nitric acid tank 2c (see Fig. 2C). However, the concentration of dissolved oxygen can be controlled.

If necessary, a diffuser such as a blower may be provided to supplement the oxygen content. The air diffuser can be installed in the biofilm bed transfer unit, but maintenance is required between each biofilm bed transfer unit and the bioreactor, and between the biofilm bed transfer unit and the biofilm bed transfer unit. Turbulence in the liquid flow in the biological reaction tank Therefore, mixing is preferred.

According to the present invention, when municipal sewage as sewage (water to be treated) is treated with a residence time equivalent to the standard method, total nitrogen should be 8 mg / L or less and total phosphorus should be 0.5 mg / L or less. Was possible. At this time, it was sufficient to double the amount of air supplied by the blower (aeration device) to the amount of sewage. In other words, the amount of air diffused was one half that of the standard method and one fourth that of the advanced treatment method.

Based on these results, we designed a biological treatment system that treats 10,000 tons of sewage in urban areas, and found that the required power could be reduced by 20% to 40% compared to conventional biological treatment systems. .

According to the present invention shown in FIGS. 1 to 3C, the following effects can be obtained.

(1) The biofilm bed is deflected by the rollers, so it is difficult for excess biofilm to reach the biofilm bed. Therefore, fresh microorganisms always adhere to the biofilm bed, and the metabolic activity is always high. In addition, there is no need to overestimate the required power, which saves energy.

(2) By moving the biofilm bed, the biofilm can be effectively attached to the biofilm bed, and the sewage in the reaction tank can be stirred. Furthermore, by introducing a part of the biofilm bed to air, it becomes possible to supply oxygen to the sewage in the reactor.

(3) Since the present invention is not limited to the aspect ratio of the reaction tank, the present invention can be applied to all existing biological reaction tanks. In addition, since the amount of organisms attached to the biofilm bed increases, it is possible to upgrade from the standard method to the advanced treatment method without increasing the number of reactors.

Next, a biological treatment apparatus according to a second embodiment of the present invention will be described with reference to FIGS. 4 to 11C. Note that the configuration and operation of the second embodiment, which is not particularly described, are the same as those of the first embodiment, and a duplicate description thereof will be omitted. FIG. 4 is a schematic diagram showing a biological treatment device according to a second embodiment of the present invention. In FIG. 4, the sheet-like three-dimensional network structure 27 as a biofilm bed moves vertically in the biological reaction tank 2, and a biofilm is formed on the surface of the three-dimensional network structure 27. When the three-dimensional network structure 27 moves up and down, oxygen in the air can be taken into the liquid in the biological reaction tank 2 when the three-dimensional network structure 27 is submerged in the liquid from the air. The liquid itself can be stirred by the three-dimensional network structure 27, and the activated sludge 6 and the three-dimensional network Since the microorganisms released from the structure 27 can be sufficiently mixed, they can be guided to the sedimentation tank 3 without causing the microorganisms to sediment in the biological reaction tank 2. An aeration device 28 is arranged at the bottom of the biological reaction tank 2, and air is diffused into the raw water 1 from the aeration device 28. The sludge 4 settled in the settling tank 3 returns to the biological reaction tank 2 as returned sludge 5, and the activated sludge 6 is present in the biological reaction tank 2. When only the treatment with the biofilm is performed and the activated sludge 6 is unnecessary, the returned sludge 5 may be omitted, and the aeration device 28 may be omitted. Further, when it is not necessary to remove the detached biofilm, the settling tank 3 can be omitted.

FIG. 5 is a schematic diagram conceptually showing the appearance of a three-dimensional network structure, a so-called sponge-like structure of the biological treatment apparatus shown in FIG. The mesh structure may be a rib structure, a wall structure, or any other structure, but air or liquid is easily leaked and easily permeated. In other words, the structure is such that liquid and air can be exchanged smoothly. is important. The size of the hole 27a can be used without any problem as long as the diameter is in the range of 0.2 to 3 mm, and is preferably 0.5 to 2 mm. The material of the three-dimensional network structure 27 preferably has sufficient strength, elasticity and abrasion resistance, and is excellent in hydrophilicity and biocompatibility. The main materials of the three-dimensional network structure 27 include polyurethane, polyethylene glycol / le, senorelose, polystyrene, and vinylon, but other materials are added to improve hydrophilicity and strength. I'm sorry. The thickness of the sheet-shaped three-dimensional network structure 27 can be used if it is 2 to 50 mm, but is preferably 3 to 3 O mm. In addition, when the three-dimensional network structure 27 is released from contraction due to compression, if it has a compression recovery property of returning to the original thickness, it can be used without any problem, so it is extremely high No elasticity is required. Rather, it is important that the compression recovery rate is kept above a certain level for a long time. Considering maintenance, it is desirable that elasticity be maintained for at least one year.

The sheet-like three-dimensional network structure 27 is subjected to physical processing mainly for the purpose of reinforcement, operability, and improvement of functionality, and can be used as a processed product. The processing method of the three-dimensional network structure 27 may be any method as long as the three-dimensional network structure 27 is not kinked, pulled, damaged, stuck, or subjected to extreme friction. For example, as shown in Fig. 6A, processed material 29a, a cloth material 30 such as a filter cloth, non-woven cloth, or a mesh is attached to the three-dimensional net structure 27 by bonding, pressing, sewing, or the like. You may. Further, as shown in the processed product 29 b in FIG. 6B, the net-shaped holding material 31 may be attached to the three-dimensional net self-structure 27 by processing such as bonding, crimping, scissoring, and wrapping. . Or, as in the processed product 29c in Fig. 6C, the cloth-like material 30 or the net-like holding material 31 is sandwiched by two or more three-dimensional mesh structures 27 by bonding, crimping, sewing, etc. It may be. These processed products are examples, and the present invention is not limited thereto. As a matter of course, it is not always necessary to process the entire surface of the three-dimensional network structure 27.

As a moving mechanism for moving the sheet-shaped three-dimensional network structure 27 up and down, a configuration shown in FIG. 7 is exemplified. That is, both ends of one sheet-shaped three-dimensional network structure 27 are connected to form an endless, and the three-dimensional network structure 27 is rotated in an annular shape by the rollers 22a and 22b. This configuration is an example, and the moving mechanism is not limited to this. The sheet-like three-dimensional network structure 27 may be changed to processed products 29 a to 29 c shown in FIGS. 6A to 6C. Further, as shown in FIGS. 8A to 8C, the belt 13 is directly attached to the inner peripheral surface of the sheet-shaped three-dimensional network structure 27, and the guide 14 is attached to the roller 22a. A configuration using an auxiliary tool such as holding 3 is also feasible. By increasing the number of rollers, a single sheet can be used to form a multi-stage structure, improving the efficiency per unit. Fig. 9 shows an example of a multi-stage biofilm bed transfer unit installed in a biological reaction layer. If you do not want to dissolve oxygen in the liquid as in anaerobic tanks or anoxic tanks, it is recommended that all rollers 22a and 22b be submerged. It should be noted that a part or the whole of the sheet-like three-dimensional network structure 27 may be the processed product 29 a to 29 c as a matter of course.

As shown in FIG. 10, a compression structure 15 for compressing the three-dimensional network structure 27 can be provided at an arbitrary point. In this case, the three-dimensional network structure 27 compressed by the compression structure 15 discharges the sewage and air taken in, thereby promoting the supply of oxygen. The number of the compression structures 15 may be one or two or more. The compression structure 15 can be installed in the air, the liquid, or both. When the compression structure 15a is provided so that the compression point is in the air, the three-dimensional network structure 27 is compressed by the compression structure 15a, and the wastewater contained in the three-dimensional network structure 27 is discharged. Flow down. Then, the effects of aeration and stirring on the wastewater in the biological reaction tank 2 can be obtained. Furthermore, the compressed three-dimensional network structure 27 contains air with the recovery of thickness, The oxygen supply in the liquid is better: Further, the weight of the liquid can be removed from the three-dimensional network structure 27, and the required power can be reduced. When the compression structure 15b is provided so that the compression point is in the liquid, oxygen is diffused into the biological reaction tank 2 by diffusing air from the three-dimensional network structure 27 that has taken in air. Supplied. Further, the standing mesh structure 27 newly contains sewage in the biological reaction tank 2 and moves into the air again. This promotes oxygen supply and sewage agitation. If the compression structure 15c is installed under the roller 22b, which is the lowermost part of the three-dimensional network structure 27, air can be exhausted at the deepest point, which is preferable from the viewpoint of oxygen supply.

The shape of the compression structure 15 may be a polygonal prism or a cylinder. The space between the three-dimensional network structure 27 and the compression structure 15 can also be freely adjusted, and the depth at which the three-dimensional network structure 27 is pressed can be adjusted. In addition, the compression structure 15 does not necessarily have to have a size and a shape to compress the entire three-dimensional network structure 27. If the compression structure 15 is a rotary compression structure 16, the compression structure 15 can be freely rotated in accordance with the movement of the three-dimensional network structure 27, thereby preventing the three-dimensional network structure 27 from moving up and down. Without increasing the required power and operating costs. Also in this case, it is preferable that the distance between the three-dimensional network structure 27 and the rotary compression structure 16 can be adjusted. This makes it possible to adjust the depth at which the three-dimensional network structure 27 is pressed, and to adjust the oxygen supply amount. The shape of the rotary compression structure 16 may be a polygonal prism or a cylinder as long as it can rotate around its axis. In particular, the cylindrical shape does not damage the biofilm, hinders the movement of the three-dimensional network structure 27 and does not cause trouble, and the same degree of compression can be stably obtained at any point. It is easy to be desirable. Regarding the excessive adhesion of the biofilm, which was a problem in the rotating disk method, the excessively attached biofilm was peeled off by the deflection of the three-dimensional network structure 27 at the rollers 22a and 22b, and the compression structure 1 5 is less likely to be a problem as the over-adherent biofilm is scraped off. Fluid and air can be expelled not only by compression but also by vibration.

[Example 3]

FIGS. 11A to 11C show examples in which the biological treatment apparatus according to the second embodiment of the present invention is applied to a reaction tank such as an aeration tank, an oxygen-free tank, or an aerobic tank. FIG. 11A is a plan view, FIG. 11B is a front view, and FIG. Is a cross-sectional view taken along the line XI-XI in Fig. 11A. is there. The configuration of the present embodiment, which is not particularly described, is the same as that of the above-described second embodiment, and a duplicate description thereof will be omitted.

In this example, six sets of biofilm bed moving units 9 (9a, 9b, 9b, 9c, 9c, 9d) are used. The biofilm bed moving unit 9 includes a plurality of rollers 22a located in the air and a plurality of rollers 22b located in the liquid, and the roller 22a and the roller 22b are a single three-dimensional network structure 27. Are connected by The partition walls 18 extend perpendicularly to the flow direction of the raw water 1, are disposed on both sides of each biofilm bed moving unit 9, and are arranged before and after each of the biological moving units 9.

As shown in FIG. 11C, a plurality of (three in this embodiment) compression structures 15a are arranged so as to be located in the air. At the bottom of the three-dimensional network structure 27, a compression structure 15c or a rotary compression structure (not shown) is provided. When the three-dimensional network structure 27 is temporarily compressed by the compression structure 15c, oxidation and nitrification of BOD further progress by aeration in a liquid. Note that a part or the whole of the sheet-like three-dimensional network structure 27 may be the processed products 29a to 29c.

Using the above biological treatment equipment, sewage (raw water) was treated at a residence time of 8 hours under the conditions shown in Table 1, and as shown in Table 2, total nitrogen 8 mgZL, total phosphorus 0 It was possible to obtain a 3 mg / L solution. At this time, it was sufficient if the amount of air replenishment by the blower (aeration device) was 1.5 times the amount of raw water. In other words, the amount of air diffused was about 3/8 of the standard method and about 3/16 of the advanced treatment method. Based on this result, we designed a biological treatment system to treat 10,000 tons of municipal sewage, and it was expected that the power required would be reduced by 25% to 50% compared to conventional biological treatment units. .

[table 1]

Raw water flow Q (m ³ / d) 10

Circulating flow 2Q

Return flow 0.5Q [Table 2]

According to the present invention shown in FIGS. 4 to 11C, since the sheet-shaped three-dimensional network structure is bent by the roller, an excessive biofilm is not easily attached to the three-dimensional network structure as a biofilm bed. Therefore, fresh microorganisms always adhere to the biofilm bed, and the metabolic activity is always high. In addition, there is no need to overestimate the required power, which saves energy. By moving the sheet-shaped three-dimensional network structure as a biofilm bed, a biofilm can be effectively attached and sewage in the reaction tank can be stirred. Furthermore, by introducing a part of the three-dimensional network structure into the air, it becomes possible to supply oxygen into the reaction tank, thereby further improving the biological treatment capacity.

Since the present invention is not limited by the aspect ratio of the reaction tank, the present invention can be applied to all existing biological reaction tanks. In addition, since the amount of organisms attached to the biofilm bed increases, it is possible to upgrade from the standard method to the advanced treatment method without increasing the number of bioreactors. Further, by pressing the compression structure against the sheet-like three-dimensional network structure, oxygen supply can be promoted, and the amount of air diffused by the air diffuser can be reduced, thereby reducing operating costs. Industrial potential

INDUSTRIAL APPLICABILITY The present invention is applicable to a biological treatment method and a biological treatment apparatus for treating sewage, and in particular, sewage such as sewage, organic wastewater, inorganic wastewater containing nitrogen, highly polluted river water, and lakes and marshes. The present invention can be applied to a biological treatment method and a biological treatment apparatus for treating a plant with a mobile biofilm bed.

Claims

The scope of the claims

1. A biological treatment method comprising: moving a cloth material up and down in a tank for treating sewage to perform agitation and biological treatment of the sewage.

2. The biological treatment method according to claim 1, wherein a part of the cloth material is introduced into the air, whereby oxygen is supplied into the water tank.

3. A biological treatment apparatus comprising: a water tank for treating sewage; and a cloth-like material installed to move up and down in the water tank.

4. A biological treatment method for biologically treating sewage, wherein the biological treatment is performed using a sheet-like three-dimensional network structure.

5. A biological treatment method for biologically treating sewage, wherein the sheet-like three-dimensional network structure is moved up and down in the sewage to perform sewage agitation and biological treatment.

6. The biological treatment method according to claim 4, wherein a part of the three-dimensional network structure is continuously or intermittently introduced into the air.

7. The biological treatment method according to claim 6, wherein the air taken into the three-dimensional network structure is discharged in sewage.

8. The biological treatment method according to claim 6, wherein the wastewater taken into the three-dimensional network structure is discharged in the air.

9. A biological treatment apparatus comprising: a water tank for treating sewage; and a sheet-shaped three-dimensional mesh structure installed to move up and down in the water tank.