JPH0975951A - Filter for purification of sewage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive filter for purification of sewage having excellent workability and purifying performance by packing a cloth or net bag with plural numbers of packing material having large porosity and preparing the can-like packing material having specified shape and dimension from a raw material which can supply iron ion to sewage. SOLUTION: This filter 1 for purification of sewage to be used for a soil- covered contact aeration tank or the like consists of a cloth or net bag 3 packed with plural numbers of packing material having large porosity. As for the packing material, a can-like packing material having 3 to 20cm length and 1 to 7cm diameter comprising a material which can supply iron ion to sewage is used. As for the can-like packing material, used cartridges 2 of photographic films are preferably used. Thereby, aerobic microorganisms deposit on the outer surface of cartridges while anaerobic microorganisms deposit on the inside, and these microorganisms have a function to decrease BOD in the sewage and an efficient denitrification function. Moreover, the iron content dissolved from the cartridges 2 reacts with a water-soluble phosphorus compd. in the sewage to remove phosphorus the sewage.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a filter medium, and in particular,
The present invention relates to a filter material for sewage purification, which is inexpensive and has high purification efficiency, which is used in sewage purification facilities.

[0002]

2. Description of the Related Art Conventionally, in purification facilities such as a soil-covered anaerobic tank, a soil-covered contact aeration tank, a capillary moistening trench, and a rainwater storage / infiltration water tank or trench, it is naturally learned to filter media such as gravel, crushed stone, and sand. (Hereinafter, simply referred to as a filter medium) has been used, but in recent years, a plastic filter medium has also been used.

In this case, although gravel and crushed stone are inexpensive,
In contrast to the heavy and poor transportability and workability, the plastic filter medium has the drawback of being lightweight and excellent in workability, but also costly. Therefore, it has been attempted to utilize waste such as empty cans and PET bottles, but in order to use these as filter media, it is necessary to make a large number of holes so that water can easily enter and leave, There is a drawback that the work cost for that is increased.

For example, in the case of a soil-covered contact aeration tank,
While sludge accumulated between filter media is effective for denitrification in wastewater (Japanese Patent No. 1085714), the accumulated sludge causes clogging of the filter media. Therefore, in order to prevent this, it is necessary to lower the water level of the sewage in the tank, take out the filter medium from the filter medium take-out hole, and remove the adhered sludge, which is an extremely complicated work.

Therefore, instead of such a method, a method of supplying a large amount of air to the air diffusing pipe to separate sludge accumulated by the air and removing clogging between the filter media is adopted. In this case, when an empty can or a PET bottle is used as the filter medium, it is necessary to make a large number of holes in the filter medium in advance as described above.

In the treatment of sewage, not only the denitrification function but also the removal of phosphorus which causes eutrophication of water in rivers and lakes (hereinafter referred to as dephosphorization) is important. As a dephosphorization method, for example, a method of immersing an iron plate in sewage to elute iron ions and combining the iron ions with a water-soluble phosphorus compound in sewage to form a salt insoluble in water is removed. is there.

As a sewage treatment apparatus using such a dephosphorization method, a dephosphorization septic tank using an iron plate inside has already been developed. However, although this septic tank has an excellent dephosphorization function, it has a drawback that the denitrification performance is not sufficient. Therefore, in order to improve both the denitrification and dephosphorization functions, the method of using an empty can made of steel as the filler for the contact filter medium (Japanese Patent Laid-Open No. Sho 60-95018) has an attractiveness that is difficult to throw away.

[0008]

Therefore, as a result of diligent research on the filter material for purifying sewage in order to improve the above-mentioned drawbacks, the present inventors have found that the used cartridge, which is a scrap material, is extremely useful as a filter material. That is, and, not only the workability is improved by packing it in a bag, but by incorporating an appropriate amount of a floating material in the bag, the specific gravity of the entire bag as a filter material can be appropriately adjusted. In addition to being easily adaptable according to the purpose of use, the Patrone does not have to be perforated like an empty can and can be used as it is. did.

Therefore, a first object of the present invention is to provide an inexpensive sewage purification filter medium which is excellent in workability and purification performance. A second object of the present invention is to provide an inexpensive sewage purification filter medium capable of adjusting the specific gravity of the entire filter medium and easily corresponding to the purpose of use. A third object of the present invention is to provide a filter medium for purifying sewage, which reuses a waste cartridge.

[0010]

The above-mentioned various objects of the present invention are a filter medium containing a plurality of fillers having a large porosity in a cloth-like or net-like bag, wherein the filler is iron in waste water. 3 cm to 20 cm in length, made of a material that can supply ions
This is achieved by a filter medium for purifying wastewater, which is a can-like filler having a diameter of 1 cm to 7 cm and a cartridge shape for photographic film or a shape similar thereto.

The length used in the present invention is 3 cm to 20 c.
The can-like filler having a diameter of 1 cm to 7 cm, which is made of a material capable of supplying iron ions into the waste water, is appropriately selected from the can-like fillers that allow water to easily enter and exit as well as a photographic film cartridge. However, it is particularly preferable to use an inexpensive patrone which is produced as a large amount of photographic film waste. Since the patrone is an iron material, it improves the dephosphorization performance for sewage, as described later.

When the cartridge is used, for example, as a filler for a contact filter medium in a contact aeration tank, aerobic microorganisms adhere to the surface of the cartridge and anaerobic microorganisms adhere to the inside of the cartridge, and these microorganisms It lowers the BOD in wastewater and performs denitrification efficiently.

Further, in the wastewater, iron eluted from the cartridge is combined with the water-soluble phosphorus compound in the wastewater to form a water-insoluble salt, so that phosphorus in the wastewater is removed. The salt deposited from sewage is reduced to soil and becomes fertilizer.
From the viewpoint of accelerating the dephosphorization action, it is preferable to use the one in which the synthetic resin film, the label and the like on the surface of the cartridge are removed by incineration or the like, and it is also preferable to add the molten iron bacteria to the waste water.

In the present invention, the filler is contained in the cloth-like bag in order to prevent inflow of mud and the like into the filter medium and to improve workability in filling and replacing the filter medium. The cloth in this case is not particularly limited as long as it has water permeability and durability. In the present invention, as a cloth used for such a bag, it is preferable to use a nonwoven fabric from the viewpoint of durability. In particular, when using it in a contact aeration tank (contact filter bed method) installed in the ground of a riverbed, from the viewpoint of pollution prevention, use a degradable nonwoven fabric that is easily decomposed when it flows into a lake or the sea. Is preferred.

In the present invention, it is preferable to appropriately bind the filter medium so that the surface of the filter medium becomes uneven. The size of the bound filter medium is not particularly limited,
From the viewpoint of facilitating charging and discharging from the manhole, it is preferable that the width is 20 to 40 cm, the length is 40 to 60 cm, and the thickness is 20 to 40 cm.

When the filter medium of the present invention is used in a soil purification method that requires covering with soil, it is preferable to use a mesh bag as the bag. Since soil animals such as earthworms can easily enter and leave the net-like bag, the filter material is prevented from being clogged by the predation action of the animals. As the above net,
Particularly, from the viewpoint of durability, it is preferable to use a net made of synthetic resin such as polyethylene.

The filter medium of the present invention can be put into a contact aeration tank already installed and used. In this case, it is preferable to use a filter material having a low bulk specific gravity so as to float on water. The bulk specific gravity of the filter medium of the present invention is
For example, a foamed resin or a synthetic resin having a hollow inside can be easily adjusted by appropriately mixing the inside of the bag. The bulk specific gravity is particularly preferably 0.2 to 0.4.

In the filter medium of the present invention, a plurality of patrones are put in a bag made of the cloth or net as described above to bind the entrances, and the contents are cross-bound with a string so that the surface becomes uneven. It is preferable to manufacture by this. In this way, the string is crossed and bound so that the surface becomes uneven so that excess sludge is less likely to be deposited between the filter media and the filter media can be easily taken out during replacement.

[0019]

Next, the filter medium of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic plan view showing an example of the filter medium of the present invention. Reference numeral 1 in FIG. 1 represents the filter medium of the present invention,
2 is an irregularly filled patrone, 3 is a non-woven bag filled with patrone 2, 4 is the entrance part of the bag 3 in which the patrone 2 is enclosed in the bag 3 and the entrance is tied with a string Reference numeral 5 denotes a string formed by intersecting and binding the bag 3 so that the surface of the bag 3 becomes uneven.

Next, the method of using the filter medium of the present invention will be described in more detail with reference to the drawings. FIG. 2 is a schematic cross-sectional view of a soil-covered contact aeration tank for treating polluted river water provided on a riverbed, which uses the filter medium of the present invention. 6 in FIG. 2 is
A rubber water tank buried in the ground, 1 is a filter medium of the present invention containing a patrone 2, 7 is a tunnel type sewage ditch, 7'is the basis of the sewage ditch 7 and 8 is air for aerating the sewage It is an air diffuser.

After the filter medium 1 is filled in the outside of the wastewater ditch in the tank 6, the soil is backfilled through the soil fall prevention net 9 to form the coated soil layer 10. The tank without the air diffuser 8 is a soil-covered anaerobic tank. In the case of equipment for treating polluted river water, the above-mentioned soil coating anaerobic tank and the soil coating contact aeration tank are usually combined.

Purification of the sewage in the soil-covered contact aeration tank is carried out by the contact oxidation by the air aerated from the air diffusing tube 8, the BOD lowering effect by the aerobic microorganisms adhering to the surface of the patrone in the filter medium, and the inside of the patrone. It is performed by the denitrification action of anaerobic microorganisms attached to the. Further, the removal of phosphorus in the wastewater is carried out by eluting the iron content in the cartridge as iron ions and combining the ions with the water-soluble phosphorus compound to form a salt insoluble in water.

Further, scum having a high filth concentration is deposited on the surface of the sewage, which is eaten by soil animals in the covered soil, so that clogging of the upper part of the filter medium is prevented. Also,
The nutrients caught between the filter media are also eaten by soil animals, so clogging by these is also prevented.
Furthermore, since the covered soil also has a function of deodorizing the air that has been diffused, the problem of odor associated with wastewater treatment can be solved. The purification action in the soil-covered anaerobic tank is almost the same as the above except that there is no catalytic oxidation or purification by aerobic microorganisms.

FIG. 3 is a schematic cross-sectional view when the filter medium of the present invention is used in the merged advanced treatment capillary wet trench.
In the case of such a capillary wet trench, the sewage flowing out from the perforated pipe is purified by the action substantially similar to the above, but most of the treated water permeates the soil by the capillary siphon phenomenon, and Will be returned. In this case, since it is a merger process, in order to treat the treated water from the single septic tank, the kitchen drainage and the disposer drainage separately, the sewage is purified in three systems and the treated water is collected in the sewage box. Drained.

FIG. 4 is a cross-sectional schematic view of a case where two systems are provided in which normal treated capillary wet trenches are alternately used to allow all treated water to penetrate into the ground because there is no discharge destination. It is a figure. Figure 5 shows a roof tank for storing and infiltrating rainwater.
It is a cross-sectional schematic diagram at the time of using the filter medium of this invention. Figure 6
[Fig. 3] is a schematic cross-sectional view when the filter medium of the present invention is used in an infiltration trench for underground irrigation. FIG. 7 is a schematic cross-sectional view when the filter medium of the present invention is used in the permeation well. They are,
Rather than directly purifying sewage, rainwater is stored and excess or all water is allowed to penetrate the soil and returned to the ground.

[0026]

INDUSTRIAL APPLICABILITY The filter medium for purifying sewage of the present invention is excellent in environmental friendliness and extremely inexpensive because it reuses the patrone, which can be said to be industrial waste to be landfilled, as a filler. Further, since the patrone has a structure that is lightweight and excellent in wastewater treatment, the filter medium of the present invention using the patrone is excellent in transportability and workability, and in vaginal deficiency and dephosphorization performance.

Further, since the filter medium of the present invention can appropriately adjust the specific gravity of the entire bag as a filter medium by incorporating an appropriate amount of the floating material, it can be easily adapted to the intended use. Further, since the filter medium of the present invention has many voids,
When used in a tank for storing and infiltrating roof rainwater, the amount of water stored can be increased as compared with the conventional case where crushed stone is used. Further, since the sewage in the filling material can easily enter and leave, it is easy to remove the sludge by adjusting the amount of the sewage.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an example of a filter medium of the present invention.

FIG. 2 is a schematic cross-sectional view when the filter medium of the present invention is used in a soil-covered contact aeration tank.

FIG. 3 is a schematic cross-sectional view in the case where the filter medium of the present invention is used in the combined advanced treatment capillary wet trench.

FIG. 4 is a schematic cross-sectional view when the filter medium of the present invention is used in two systems of capillary wet trenches.

FIG. 5 is a schematic cross-sectional view when the filter medium of the present invention is used in a tank for storing and infiltrating roof rainwater.

FIG. 6 is a schematic cross-sectional view when the filter medium of the present invention is used in an infiltration trench for underground irrigation.

FIG. 7 is a schematic cross-sectional view when the filter medium of the present invention is used in a permeation well.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter medium of the present invention 2 Patrone 3 Bag 4 Bundling part of the bag in which Patrone is included 5 Bundling cord 6 Water tank 6'sheet 7 U-shaped groove 7'Pedestal 8 for supporting U-shaped groove 9 Net 10 Soil layer 11 Perforated pipe 12 Water conduit 13 Submersible pump 14 Pumping pipe 15 Masu 16 Sand layer 17 Permeation well 18 Pit 19 Permeation trench 20 Rainwater outflow perforated pipe 21 Perforated pipe as drainage means 22 Opening 23 Discharge pipe 24 Rainwater pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiko Nakade 2-28-15 Nakai, Shinjuku-ku, Tokyo (72) Yoshimasa Anayama 26026 Moro, Kanuma City, Tochigi Prefecture Sanoya Industry Co., Ltd.

Claims (5)

[Claims] 1. A filter medium containing a plurality of fillers having a large porosity in a cloth-like or net-like bag, wherein the filler is made of a material capable of supplying iron ions into wastewater, and has a length of 3 cm to. Two
A filter material for purifying sewage, which is a can-shaped filler having a 0 cm diameter and a 1 cm to 7 cm diameter for a photographic film, or a shape similar thereto. 2. The filter medium for sewage purification according to claim 1, wherein the can-like filler is a used cartridge. 3. The sewage purification filter medium according to claim 1, further comprising a synthetic resin float as another filler. 4. The filter medium for purifying sewage according to claim 1, which has a bulk specific gravity of 0.2 to 0.4. 5. A filter medium having a width of 20 to 40 cm and a length of 40 to
60 cm and a thickness of 20-40 cm.
The filter material for sewage purification described in any one of to 4.