JPH0138557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wastewater treatment device most suitable for gray water facilities such as buildings.

Various wastewater treatment systems have been proposed that treat wastewater from large-scale office buildings, hotels, residential complexes, etc., and reuse it as gray water for toilet flushing, cooling water, miscellaneous water (sprinkling water, car washing water), etc. .

A typical wastewater treatment device used in this gray water facility is the device shown in FIG. 1. In this device, after raw water is biochemically purified by the activated sludge method in an adjustment tank 10, an aeration tank 12, and a settling tank 14, it is transferred from a pump tank 16 to a sand filter tank 18, a backwash water tank 20, an activated carbon adsorption tower 22, and a sterilizer. 24, tertiary processing is performed.

However, this treatment equipment requires skill to handle because the operation management of activated sludge is complicated, and a large sedimentation tank is required to separate activated sludge and treated water, which occupies a large installation space. equipment costs,
It is unsuitable for gray water facilities inside buildings because of the problem of high operating costs.

In addition, as other treatment equipment, a treatment equipment that performs an activated sludge method and a filtration method, which is a physical treatment method, in a single aeration filtration equipment, and a treatment equipment that combines a micro screen and an ultrafiltration method have also been proposed. However, the former combines an aeration tank and an overtank above and below, so the effective height of the installation location is at least 4.5 m or more, and there are many automatic valves for water backwashing and air cleaning, reducing the frequency of failures. Management to reduce the size is complicated. Furthermore, the latter method has a high residual concentration of dissolved organic matter in the treated water, and requires combination with a biochemical treatment device or an activated carbon adsorption device, resulting in increased costs.

In view of the above-mentioned prior art, it is an object of the present invention to provide a wastewater treatment device for medium-sized water supplies that requires a small installation space, is easy to operate and manage, has low equipment costs and operating costs, and can obtain high quality water. .

The wastewater treatment device according to the present invention includes a rotating disk bed,
By biochemically purifying wastewater using biofilm beds such as submerged fixed biofilm beds, sprinkled beds, and fluidized biofilm beds, the amount of sludge generated, that is, the SS in the treated water in this process. (Suspended matter) concentration can be lowered, and by using an external pressure type porous material hollow tube or fibrous precision filtration device, the sedimentation tank normally required for biological treatment methods is not required, and the circulation Over (partial over)
This eliminates the need for overflow, making it possible to evaporate the entire amount with low energy.

By simplifying the process as described above, the installation area is reduced and operation management is facilitated. In addition, since a biofilm bed is used, high-level biochemical treatment is possible, and in addition to high-level treatment of BOD (biochemical oxygen requirement) and COD (chemical oxygen requirement), NH ₄ ⁺ -N It is easy to convert (ammoniac nitrogen) to NO ₃ ^- -N (nitrate nitrogen), and by using ultra-precision filtration, it is possible to remove extremely fine suspended matter and obtain high-quality treated water. Usually coliform bacteria, other pathogenic bacteria,
It is possible to sufficiently eliminate general bacteria, and by making the pore diameter of the ultra-precise porous material sufficiently small, it is also possible to remove viruses. Therefore, a feature of the present invention is that it is possible to improve the water quality as described above while taking advantage of the simplification of the process as described above, thereby increasing the range of purposes for which treated water can be used.

In addition, the small amount of excess sludge produced, which is a characteristic of biofilm beds, is maintained, which is extremely useful for gray water facilities such as buildings.

The reason why the external pressure type hollow tube group or hollow fiber group is used as the ultra-precision method in the present invention is because the particle size of suspended matter in the treated water flowing out from the biofilm bed tank is extremely large. This is because in the internal pressure type, sealing occurs within the tube or fibers, resulting in failure, and treatment such as backwashing for recovery cannot be performed. In addition, if it is made into a flat plate, the inconveniences such as the tube or fiber shape of the internal pressure type mentioned above can be avoided, but in order to obtain the required overarea, it becomes a huge overflow device, which is impractical and also requires backwashing for recovery. is disadvantageous compared to external pressure type tube or fibrous filtration devices. That is, by using an external pressure type tube or fibrous filtration device, it is possible to directly perform ultra-precise filtration of the water flowing out from the biofilm bed tank.

Embodiments of the present invention will be described below with reference to the drawings.

In the wastewater treatment apparatus of this embodiment shown in FIG. 2, adjustment tanks 1 are arranged sequentially from upstream to downstream.
0, submerged fixed biofilm bed tank 30, pump tank 1
6. The main part is constituted by an ultra-precision filter device 32, a water filter tank 34, and a treated water tank 36.

A screen 38 is provided upstream of the adjustment tank 10. This screen 38 has a width of 0.75, for example.
mm gravity type, which removes large suspended objects (SS) from raw water.
After removing the water (min.), the water is poured into the adjustment tank 10.

A diffuser pipe 4 leading to a blower 40 is connected to the adjustment tank 10.
1. A pump 42 is provided to send the raw water after preliminary aeration to the submerged fixed biofilm bed tank 30 via a metering tank 44 in fixed quantities.

In the submerged fixed biofilm bed tank 30, as shown in FIG. 3, the honeycomb body 46 is immersed with its axis vertical. Microorganisms adhere to the surface of this honeycomb body due to the flow of sewage and form a biofilm, and the organic matter is decomposed and purified by the microorganisms. In addition, this biofilm has BOD (biochemical oxygen demand) and COD (chemical oxygen demand).
High removal rate of ammonia nitrogen, etc., and SS
(Suspended solids concentration) can be lowered. Therefore, the treated water can be directly led to the ultra-precision filtration device 32 without requiring a settling tank as in the conventional example.

An aeration pipe 48 communicating with a blower 47 is disposed below the honeycomb body 46 to aerate and flow the treated water in the tank to bring it into contact with the biological film.

As an example, a plurality of hollow bodies 50 as shown in FIG. 4 are arranged in the ultra-precision passing device 32. This hollow body 50 is a PVA (polyvinyl alcohol)-based hollow fiber membrane, and has a plurality of through holes 5 in the radial direction.
2 is formed. This through hole 52 has a particle size of 1 μm.
It is large enough to capture even smaller SS, bacteria, colloids, etc. In Figure 4, white circles represent SS, bacteria, colloids, etc., black circles represent water,
Shows ions and salt particles.

Moreover, these hollow bodies 50 are cylindrical bodies (not shown).
The inside of this cylindrical body is under high pressure (1~3Kg/
cm ² ), the treated water is passed from the outside of the hollow body 50 through the through hole 52, and the treated water is taken out from the inside to the water tank 34. In this way, the ultra-precision filtering device 32 has a structure in which the treated water is passed from the outside to the inside of the hollow body 50, so even if the fine particles contained in the treated water supplied from the pump tank 16 clog the through hole 52, it will not be reversed. It can be easily removed by washing.

To explain the operation of this embodiment configured in this way, raw water is primarily treated with the screen 38 to remove coarse substances, and then sent to the adjustment tank 10. Aeration pipe 4 leading from the blower 40 of this adjustment tank 10
After being pre-aerated in step 1, it is sent to a submerged fixed biofilm bed tank 30 for secondary treatment.

In this submerged fixed biofilm bed tank 30, wastewater flows through a diffuser pipe 48 leading to a blower 47 and comes into contact with the biofilm of the honeycomb body 46, thereby purifying the wastewater.

The entire amount of treated water purified by the submerged fixed biofilm bed is subjected to tertiary treatment of solid-liquid separation in an ultra-precision filtration device 32, then disinfected in a sterilizer 24, and reused as gray water.

The ultra-precision filtering device 32 periodically performs water backwashing and air backwashing to prevent clogging, and the cleaning wastewater from the water backwashing is returned to the adjustment tank 10 or discharged to the sewer.

In addition, in the above embodiment, a structure is shown in which the honeycomb body 46 is used in the submerged fixed biofilm bed tank 30.
The present invention may be configured as long as microorganisms are attached to form a biofilm, and wastewater is fluidly purified while coming into contact with this microbial film. In addition to honeycombs, the following materials or supports are generally used for beds on which biofilms are deposited, and any of them can be applied to the biofilm bed of the present invention.

(i) Granular filter media: sand, gravel, crushed stone, flint, activated carbon, coke, coal husk, persimmon husk, plastic pieces, cork pieces, wood pieces, fiber waste, etc.

(ii) Molded granular filter media: interlock saddles, Raschig rings, pipe pieces, deformed pipe pieces (Reuse Y), terrarettes, pole rings, etc.

(iii) Rod-shaped and string-shaped filter media: wooden sticks, bamboo strips, multi-ring strings, (ring lace), etc.

(iv) Flat/corrugated filter media: asbestos boards, wood boards, plastic pieces, plastic nets, corrugated boards, etc.

(v) Porous filter media: porous cylinders, honeycomb tubes, loofahs, etc.

Although this example uses a submerged fixed biological bed, any other aerobic biofilm beds such as rotating disk beds, sprinkled beds, fluidized beds, etc. can be used in the present invention. be.

Further, in the above embodiments, a porous hollow body was used as the ultra-precision filtration device, but the present invention can be applied to any porous filtration body having a desired particle size.

As explained above, the wastewater treatment device according to the present invention uses a biofilm bed tank and an ultra-precision filtration device, so a settling tank is not required, the installation space is reduced, operation management is easy, and excess sludge is discharged outside the system. Since the amount of water is extremely small, equipment costs and operating costs can be reduced, and at the same time, high quality water can be obtained (at low cost and in large quantities).

[Brief explanation of drawings]

Fig. 1 is a flowchart showing a conventional wastewater treatment device, Fig. 2 is a flowchart showing an embodiment of the wastewater treatment device of the present invention, Fig. 3 is a perspective view showing the internal structure of a contact oxidation tank, and Fig. 4 is a flowchart showing an embodiment of the wastewater treatment device of the present invention. FIG. 3 is a sectional view showing a hollow body of the precision passing device. 10...Adjustment tank, 30...Contact oxidation tank, 32...
...Ultra precision device, 46...Honeycomb body, 50...
...Hollow body, 52...Through hole.

Claims (1)

[Claims] 1. The wastewater is flowed and purified while contacting the biofilm to the downstream of the aerobic biofilm bed, where particle size
An ultra-precision filtration device equipped with a porous material capable of capturing particles of 1 μm or less is arranged, and the ultra-precision filtration device consists of a group of hollow tubes or a group of fibers. A wastewater treatment device that pressurizes the inside and passes the entire amount through.