JP2584384B2 - Method and apparatus for treating organic sewage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention highly purifies physicochemically and biologically various organic wastewaters such as sewage, in particular, organic wastewater containing a relatively large amount of SS, using a very rational new apparatus. It is related to processing technology.

[0002]

2. Description of the Related Art FIG.
As shown in the figure, an air diffuser 15 is provided at an intermediate portion of the tank body 12, a biological treatment section filled with a floating filter medium 13 is provided above the air diffuser 15, and a stirring means is provided below the air diffuser 15. Disclosed is a processing technique in which raw water is supplied from the sedimentation section 15 to the tank body 12 that has become the sedimentation section 16 in an upward flow to remove SS of the raw water and perform biological treatment in the same processing tank.

[0003] The results of treating sewage by the technology disclosed in the above-mentioned publications are desired to be improved from the state of the art in the following points. That is, the microorganism holding amount of the floating filter medium is not large. Further, SS easily leaks into the treated water from the biological treatment section filled with the floating filter medium. It is difficult to remove the clogging of the packed bed of the floating medium, and it takes a long time to clean the packed bed. In addition, SS which did not completely settle in the sedimentation section of the treatment tank
Therefore, the bottom of the packed bed of the floating medium is likely to be clogged.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to establish a new processing system which can properly solve the above-mentioned problems of the conventional apparatus.

[0005]

SUMMARY OF THE INVENTION The above object is achieved by the following organic wastewater processing methods and apparatus of the present invention. 1) Organic sewage is placed in a single tank with three-dimensional mesh
Bed A filled with a filter medium and a hollow granular filter
It is installed in combination with a packed filter bed B filled with material
Flushed with upflow introduced from parts, filtering the SS in a packed filter bed B filled with hollow granules filter material, then the aerobic biofilm treatment in a packed filter bed A filled reticulated granulate filter material A method for treating organic wastewater.

2) A means for supplying organic sewage in the lower part of the treatment tank and a means for outflow of treated water in the upper part of the treatment tank, and a filled filter bed filled with a three-dimensional mesh filter material in the upper part of the treatment tank. A, a packed filter bed B filled with a hollow particulate filter medium is provided at a lower portion thereof, and the inside or lower portion of the packed filter bed A is provided.
A diffuser is provided for supplying oxygen to the filter bed, and air is supplied to the lower part of the packed filter bed B for stirring during washing.
Organic wastewater processing apparatus characterized by deploying an air diffusion means that.

[0007] The gist of the present invention is the above-described conventional apparatus.
In order to solve the above-mentioned problem, the present invention is to perform SS precipitation filtration using a packed filter bed B of a hollow particulate filter medium. However, the lower part of the single treatment tank may be used as a sedimentation part. In that case, a flocculant may be added to the sewage as required, and then introduced into the treatment tank.

A feature of the present invention is that a hollow particulate filter medium is used as a filter medium to be filled in a packed filter bed B provided in a settling portion below a packed filter bed A. As shown in FIG. 2, the shape of the hollow particulate filter medium may be cylindrical, spherical, or any other polyhedron having openings on the side surfaces. Filled filter bed B filled with the hollow particulate filter medium
When the organic sewage is passed through the filter, the hollow particulate filter medium has a very large porosity of 95% or more as described in more detail below. Is trapped and removed while passing through the filter media.

The mechanism of removal at the stage of capturing SS by the hollow particulate filter medium is not filtration, but each hollow filter medium acts as a micro-sedimentation basin, and SS is formed in the sedimentation basin composed of the hollow filter medium. It seems to settle out. The SS trapping action of the hollow particulate filter material plays a large role in achieving the object of the present invention.

A specific embodiment of the organic wastewater treatment apparatus of the present invention will be described with reference to FIG. 1 in order to better understand the configuration of the present invention. However, the processing apparatus of the present invention is not limited by the specific embodiments described below.

FIG. 1 shows an example of a processing tank 1 of a processing apparatus according to the present invention, which is provided with a porous water-passing member 2 stretched in the middle of the processing tank 1 so as to cross the tank 1 horizontally. A packed filter bed A filled with such a three-dimensional mesh-like granular filter medium, and a hollow such as one example of a hollow cylindrical filter medium and one example of a hollow spherical filter medium shown in FIG. And a packed filter bed B filled with at least one kind of granular filter material.

The three-dimensional mesh-like granular filter medium is formed so as to have continuous holes from the surface to the inside, and can be manufactured by a known foaming method or the like. The material of the granular material is not particularly limited as long as it has the above properties, and known materials such as organic polymers and inorganic compounds can be used. Among them, a material having moderate elasticity and strength in the material itself is preferable. Preferred are urethane resins and the like. For example, an elastic porous granular material such as a polyurethane foam is produced by foaming plastics such as urethane resin by a foaming method for producing open cells, and used as it is or cut into a desired shape and size. Its size is 10 to 30 mm, preferably 15 to 20 mm, and its shape can be square, spherical or various other shapes, but square is preferred. The specific gravity of the material is usually preferably about 0.9 to 1.2. Also,
The porosity is preferably 90% or more. The pore diameter, that is, the pore diameter is desirably selected from the range of 0.1 to 6 mm, preferably 2 to 4 mm. Further, the number of holes per 1 cm length is preferably 5 to 20.

The structure of the hollow particulate filter medium is not particularly limited as long as it is configured so that at least SS can be physically filtered, and there is a space inside the hollow particulate filter medium. do it. The shape may be any of a cylinder, a square tube, a hollow sphere, and a polyhedron, and preferably has an opening on the side surface of the hollow filter medium. The present inventor has found that the SS filter can be more effectively removed by providing a large number of lattice-shaped openings as shown in FIG. The particle size is 1 in the case of hollow granular material.
It is preferable to use one having a particle diameter of 0 to 15 mm and a length of 10 to 25 mm. No oxygen-containing gas is supplied to the packed filter bed B filled with the hollow particulate filter medium, and the packed filter bed B is merely a physical filtration layer. May be provided.

FIG. 1 shows a state where both the packed filter bed A and the packed filter bed B are floating, but it is needless to say that either A or B or both of them may be fixed beds in a settled state. As the porous water-permeable member 2 that separates the packed filter bed A from the packed filter bed B, a grid, a net, a perforated plate, grating, a slit, or the like can be appropriately used.

A diffuser C1 for supplying an oxygen-containing gas such as air for breathing microorganisms is provided below the packed filter bed A. Then, an oxygen-containing gas such as air is supplied from the blower D1 to the air diffuser C1 through the gas supply pipe 3. Further, an air diffuser C2 capable of disturbing both the packed filter bed B and the packed filter bed A during washing is provided below the packed filter bed B. Then, air is supplied from the blower D2 to the air diffuser C2 through the air supply pipe 4.

At the uppermost part of the treatment tank 1, there is provided an upper filter medium outflow prevention network 5 for preventing the three-dimensional mesh-like granular material filled in the packed filter bed A from flowing out. Is provided with a lower filter medium drop prevention net 6 for supporting the hollow particulate filter medium. Organic wastewater (raw water) to be treated is supplied from a raw water supply pipe 7 provided at a lower portion of the treatment tank 1 and rises in the treatment tank 1 in an upward flow to form a packed filter bed B and a packed filter bed A. In this order, the water enters the treated water outflow portion from the overflow weir above the treatment tank 1 and flows out of the system through the treated water outflow pipe 8.

In the sedimentation section 9 below the packed filter bed B of the treatment tank 1, sedimented sludge is deposited on the bottom of the treatment tank 1 and discharged out of the system through a drain pipe 10. Further, a washing water supply pipe 11 for supplying washing water at the time of washing the filter bed is opened at a lower portion of the treatment tank 1. A pump P for supplying cleaning water is provided in the middle of the cleaning water supply pipe 11.

[0018]

The operation of the processing apparatus of the present invention described with reference to FIG. 1 will be described below. Organic wastewater such as sewage is supplied to a raw water supply pipe 7 provided at a lower portion of the treatment tank 1.
And flows into the sedimentation section 9 at the lower part of the packed filter bed B, where the sedimentable SS is separated. Thereafter, the organic sewage flows upward and flows into the packed filter bed B filled with the hollow particulate filter medium, and the fine S which has not settled in the settling section 9 is formed.
Filter S.

Further, the aerobic material having a high concentration of soluble BOD, NH _{3 and the} like in the filtered water flowing out from the packed filter bed B is fixed to the inside of the three-dimensional mesh-like granular material filled in the packed filter bed A. Biofilm treatment with microorganisms to remove. In addition, the residual SS is also removed to a high degree by the principle of biological filtration, and clear treated water flows out to the surface of the water.

In the present invention, the organic sewage has a porosity of 95%.
After filtering and removing most of the SS with the hollow particulate filter medium as described above, biofiltration was carried out by microorganisms immobilized inside a large three-dimensional mesh-like granular material having a large porosity of 98%. It was found that the increase in filtration resistance between the filter bed B and the packed filter bed A was surprisingly small, and that a high-speed biological reaction proceeded.

On the other hand, in the prior art shown in FIG. 4, since the filtration of SS and the biofilm treatment are simultaneously performed only by the floating filter medium layer 13, clogging of the layer is fast, and microbial membranes are captured by the capture of SS. The biological treatment and degradation were also faster due to the reduced active surface of the.

The present invention relates to an area for performing SS filtration, ie, a packed filter bed B, and an area for promoting a biological reaction, ie, a packed filter bed A.
As a result, the drawbacks of the prior art are solved and excellent performance is exhibited. Further, it was recognized that the use of a filter medium having a lattice-like opening on the side face as shown in FIG. If the capacity of the filled filter bed B and the packed filter bed A of the treatment apparatus of the present invention to reach the SS reaches the limit, the quality of the treated water, particularly the level of SS, deteriorates. Is performed in the following manner.

That is, after the inflow of the organic wastewater is stopped, the drainage valve V1 provided in the drainage pipe 10 is opened, and the water level in the treatment tank 1 is lowered to slightly below the level of the porous member 2 and then. Close the drain valve V1. The blower D2 is driven to blow air vigorously from the air diffuser C2 through the air supply pipe 4, and the hollow particulate filter medium in the packed filter bed B is vigorously stirred for several minutes. Further, while continuing the air stirring, the drain valve V1 is opened, and all the water in the tank is discharged.

The drain valve V1 is closed, the blower D1 is driven, and sewage is supplied while violently ejecting air from the diffuser C1 through the gas supply pipe 3, thereby increasing the water level in the treatment tank to increase the air in the packed filter bed A. in stirred to remove excess microbial steric reticulated granulate filter material, opening the detergent drain valve V _2. When the washing wastewater flows over the overflow weir of the treatment tank 1 and fills the washing wastewater storage tank, the supply of the sewage is stopped, and the pump P is driven to pass from the lower part of the treatment tank 1 through the washing water supply pipe 11. The washing wastewater is supplied to the sedimentation area 9 and the SS in the washing wastewater is supplied.
After the sedimentation, the operation of circulating the washing wastewater to wash the packed filter bed B and the packed filter bed A is continued, and the SS in the washing wastewater is
When the concentration decreases, the pump P is stopped, and the cleaning drain valve V2
Close and restart the sewage supply.

The above is a typical method for cleaning the treatment tank 1 of the present invention, which has the feature that it is not necessary to consume the treated water for cleaning.

In another preferred embodiment, {1} a plurality of treatment apparatuses of the present invention are provided, and washing wastewater from some of the treatment apparatuses is supplied to the remaining treatment apparatuses as raw water to the sedimentation area. A method of purifying cleaning wastewater. {2} A method in which a polymer flocculant is added to the washing wastewater to promote precipitation of SS. Etc. can be recommended.

[0027]

The present invention will now be described in more detail with reference to the following Examples, which by no means limit the present invention. Example 1 Biological treatment of sewage was performed on the groundwater of an industrial complex by the system of the present invention shown in FIG. The conditions of the biological treatment of the present invention are as follows.

1) Average quality of raw water quality pH 7.1 SS 123 mg / liter BOD 153 mg / liter Water temperature 17 ° C.

2) Raw water treatment volume 50 m ³ / day

3) Configuration of treatment tank Diameter: 1.0 m Height: 5.0 m Height of packed filter bed B layer: 1.5 m Height of packed filter bed A layer: 2.0 m To filter bed A Supply air volume: 100 Nm ³ air / day Type of filter medium for packed filter bed B: hollow cylindrical granular material (diameter 10 mm, length 15 mm) with diagonal lattice openings on the side Material polypropylene, porosity 96% Type of filter medium on floor A: Particle size 10 × 25 × 25m
m square material Polyurethane foam Number of cells 3-4 / cm, porosity 98%

4) Duration of treatment *: 4 days (* represented by the time during which the flow of the raw water is continued from the start of the flow of the raw water to the washing of the packed filter bed)

5) Treated water quality Effluent from packed filter bed B: SS 32 mg / L BOD 63 mg / L Effluent from packed filter bed A: SS 6 mg / L BOD 4 mg / L pH 7.0 Water temperature 16.5 ° C

6) Treatment Results As described above, the sewage could be highly purified by the single treatment tank, and the clogging of the packed filter bed B and the packed filter bed A was extremely small. The microorganism concentration per 1 m ³ of the filled volume of the polyurethane foam in the packed filter bed A (biological filter bed) was as extremely high as 16 kg / m ³ .

[0034]

According to the present invention, three functions of sedimentation / separation, filtration and biological filtration can be performed in a single treatment tank, so that remarkable effects such as space saving and construction cost reduction can be obtained. There is no need to provide a separate sedimentation tank for treating the wastewater from the packed filter bed, and there is no need to consume treated water for washing the packed filter bed.

Since there is no clogging of the packed filter bed A (biological filter bed) and the concentration of microorganisms retained is high, the treatment continuation time is long,
Advanced treated water quality can be obtained. The packed filter bed B and the packed filter bed A can be easily washed. The installation of the packed filter bed B reduces the amount of SS contained in the sewage flowing into the biological filter bed A, so that there is no problem even if the flow rate in the sedimentation area is set higher than before. Therefore, the processing capacity of the processing tank is improved.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a specific example of the biological treatment method of the present invention.

FIG. 2A is a perspective view showing an example of a hollow cylindrical filter medium, and FIG. 2B is a perspective view showing an example of a hollow spherical filter medium among the hollow granular filter media of the present invention.

FIG. 3 is a perspective view showing an example of a three-dimensional mesh-like granular filter medium of the present invention.

FIG. 4 is a cross-sectional view of a typical example of a conventional biological treatment apparatus.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 treatment tank 12 tank body 2 porous water-permeable member 13 floating filter medium layer 3 gas supply pipe 14 support member 4 air supply pipe 15 diffuser pipe 5 upper filter medium outflow prevention network 16 sedimentation section 6 lower filter medium drop prevention network 17 raw water inflow pipe 7 Raw water supply pipe 18 Feed well 8 Treated water outflow pipe 19 Driving device 9 Sedimentation section 20 Rotary axis 10 Drainage pipe 21 Sedimentation sludge 11 Washing water supply pipe 22 Air blower A Fill filter bed 23 Overflow weir B Fill filter bed 24 Treatment Water outflow pipe C1 diffuser pipe 25 washing drain return pipe C2 diffuser pipe 26 coagulant injection pipe D1 blower 27 intermediate drain D2 blower 28 drain pipe V1 drain valve V2 cleaning drain valve

Claims (2)

(57) [Claims] 1. Organic sewage is solidified in a single tank at the top
Filter bed A filled with a reticulated granular filter medium and its lower part
Combined with a packed filter bed B filled with hollow particulate filter media
The SS is introduced from the lower part into the processing tank provided, flows upward , and the SS is filtered through the packed filter bed B filled with the hollow particulate filter medium.
Filtered, and then the packed filter bed A filled reticulated granulate filter material
A method for treating organic sewage, wherein an aerobic biofilm treatment is performed in the method. 2. A means for supplying organic sewage below the treatment tank,
A filled filter bed A in which a treated water outflow means is provided in the upper part of the treatment tank, and a three-dimensional mesh-shaped granular filter medium is filled in the upper part of the treated tank, and a packed filter bed B in which the lower part is filled with the hollow granular filter medium.
And an acid is placed inside or below the packed filter bed A.
A diffuser for supplying the element, and a packed filter bed B
An organic air sewage treatment apparatus , wherein air diffusion means for supplying air for agitation at the time of washing is provided at a lower portion of the apparatus.