JP2001340891A - Organic wastewater treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic wastewater treatment apparatus capable of efficiently performing the anaerobic digestion treatment of floating matter, BOD and sludge in organic wastewater without requiring excessive chemicals. SOLUTION: This organic wastewater treatment apparatus consists of a first anaerobic contact digestion tank 10 wherein a large number of anaerobic contact filter media having an expanse in a lateral direction are arranged on a plane in a lattice form and shifted zigzag up and down to be stacked in a multistage fashion, a second anaerobic contact digestion tank 20 filled with a filter medium, a final anaerobic contact digestion tank 30 filled with anaerobic contact filter media with a diameter of 3-10 mm or anaerobic contact filter media with a specific surface area of 600-2,000 m2, an aerobic contact oxidation tank 40 wherein an aerobic contact filter bed is arranged, and a disinfection equipment 50 for disinfecting treated water. A means for returning sludge generated in the second anaerobic contact digestion tank 20, the final anaerobic contact digestion tank 30 and the aerobic contact oxidation tank 40 to the first anaerobic contact digestion tank 10 is provided to the first anaerobic contact digestion tank 10 and sufficient anaerobic digestion is performed in the first anaerobic contact digestion tank 10 to discharge excess sludge 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic wastewater treatment apparatus, and more particularly, to a wastewater treatment apparatus having multiple stages of anaerobic contact digestion tanks having different functions.

[0002]

2. Description of the Related Art When discharging organic wastewater into general public waters, for example, in a sewage treatment plant, the biochemical oxygen demand (BOD) of the wastewater must be controlled to 20 mg / l or less.

[0003] In a conventional sewage treatment apparatus, aerobic treatment has been performed to reduce BOD. This is because anaerobic treatment requires a long time for the reaction and is not suitable for treating a large amount of wastewater.

[0004] Japanese Patent Application Laid-Open No. 1-44397 discloses that wastewater flows into a contact digestion tank provided with multiple stages of anaerobic filter beds for purification treatment, and the treated water further flows into a contact oxidation tank for oxidation treatment. At the same time, it is disclosed that the sludge generated in the contact oxidation tank is returned to the contact digestion tank, digested and decomposed together with the organic substances in the inflow wastewater, and the digested sludge is discharged out of the tank. According to this method, the BOD of the incoming wastewater
Is 200 mg / l, the BOD of the discharged treated water can be reduced to 10 mg / l or less. When the BOD of the inflow wastewater is 200 mg / l or more, the removal rate of BOD can be 97% or more by a combination of the contact digestion tank and the contact oxidation tank.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a wastewater treatment apparatus capable of efficiently and anaerobic digestion treatment of suspended matter, BOD and sludge of organic wastewater without requiring any extra chemicals. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION A wastewater treatment apparatus according to the present invention comprises a contact filter medium mounted on, for example, a plurality of dish-shaped support members in the form of anaerobic masses or aggregates having a lateral expansion. Are arranged at regular intervals in the horizontal direction, for example, in a grid pattern, and are partially stacked in the vertical direction at regular intervals, for example, staggered, and are staggered, for example, the first anaerobic stacked in plural stages, preferably in multiple stages. A contact digester, a second anaerobic contact digester filled with an optional contact filter, and 3 to 10
mm or specific surface area of 600 to 1 m ³
And a final anaerobic catalytic digester packed with 2000 m ² of contact filter media. Further, it is preferable to have an aerobic contact oxidation tank provided with an aerobic contact filter bed and a disinfection facility for discharging treated water from the viewpoint of coping with the environment.

[0007] The first anaerobic catalytic digester has a means for introducing organic wastewater.

[0008] The second anaerobic catalytic digester has means for introducing the treated water from the first anaerobic catalytic digester.

The final anaerobic catalytic digester has a means for introducing the treated water from the second anaerobic catalytic digester.

[0010] The aerobic contact oxidation tank has a means for introducing the treated water from the final anaerobic contact digestion tank and an air supply device.

[0011] The disinfection equipment is provided with means for introducing the treated water from an aerobic contact oxidation tank.

The first anaerobic catalytic digester has means for returning sludge generated in the second anaerobic catalytic digester, the final anaerobic catalytic digester and the aerobic catalytic oxidizer, and the first anaerobic catalytic digester is provided. The excess sludge is discharged from the tank.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the system diagram of FIG.

The wastewater treatment apparatus according to the present embodiment comprises a first anaerobic contact digestion tank 10 in which an anaerobic tank is provided with a contact filter medium as disclosed in JP-A-1-44397.
In the anaerobic tank, the second anaerobic contact digestion tank 20 filled with a normal contact filter medium, and in the anaerobic tank, a spherical or polygonal body having a size of 3 to 10 mm or a specific surface area of 600 per 1 m ^3. It comprises a final anaerobic contact digestion tank 30 filled with contact filter media of ~ 2,000 m ² , an aerobic contact oxidation tank 40 in which an aerobic contact filter bed is arranged, and a disinfection facility 50 for discharging treated water 51. .

The first anaerobic catalytic digester 10 has means for introducing the organic wastewater 1.

The second anaerobic catalytic digester 20 has means for introducing the supernatant water 11 from the first anaerobic catalytic digester 10.

The final anaerobic catalytic digester 30 has means for introducing the supernatant water 21 from the second anaerobic catalytic digester 20.

The aerobic contact oxidation tank 40 includes a means for introducing the supernatant water 31 from the final anaerobic contact digestion tank 30 and an air supply device 61.

The disinfecting equipment 50 includes an aerobic contact oxidation tank 4
A means for introducing treated water 41 from zero is provided.

The first anaerobic catalytic digester 10 has sludge 24 generated in the second anaerobic catalytic digester 20, the sludge 34 generated in the final anaerobic catalytic digester 30, and the aerobic catalytic oxidizer 40. A means for returning sludge 44 is provided, and the excess sludge 15 is discharged from the first anaerobic catalytic digester 10.

The anaerobic treatment of the organic wastewater is performed in three stages: a first anaerobic catalytic digester, a second anaerobic catalytic digester and a final anaerobic catalytic digester.

FIG. 2 is a plan view showing an end of the first anaerobic contact digestion tank, in which the upper surface of the tank and the anaerobic contact filter medium are omitted. FIG. 3 is a sectional view taken along line AA of FIG.

The first anaerobic contact digester 10 has dishes 10e, 10f, 10g, and 10h on which an anaerobic contact filter medium is placed.
Are spatially arranged. At the bottom of each dish, slit-shaped holes are provided at six places in the illustrated embodiment, and a hole with an edge for fixing is provided at the center. Anaerobic contact filter media
For example, plastics having corrosion resistance and easy to mold can be used.

In the present embodiment, a plate is used as a support member for placing the anaerobic contact filter medium. However, this member may be any member that extends in the horizontal direction, and may be a plate, an umbrella, an inverted umbrella, or the like. It can take a form such as a net or a basket. Instead of using such a member, a bulky, anaerobic contact filter having a fixed volume may be directly arranged. In any case, an aggregate of anaerobic contact filter media having a certain lateral spread or a lump thereof may be arranged. An anaerobic contact filter medium having a large volume and a certain volume includes a plastic-like material having corrosion resistance and easy to mold.

The plates 10e, 10f, 10g, and 10h are arranged at equal intervals by the spacers 10b so that the pipes 10c
And fix it vertically. Note that the pipe of the present embodiment is a support for the anaerobic contact filter medium or a support member for mounting the filter, and it is needless to say that a support for achieving the same purpose can be used without being limited to the pipe.

The pipes 10c are preferably arranged in a grid. For example, the plate 10f is adjusted by the spacer 10b such that the plate 10f is lower than the plate 10e by 1/4 of the above-mentioned interval. Similarly, for dish 10e, dish 10g
Is adjusted by the spacer 10b so that the plate 10h is located at a position lower by ／ of the interval, and the plate 10h is located at a position lower by 間隔 of the interval.

Then, as shown, the dishes 10e, 10e
f, 10g, and 10h are arranged so that they overlap each other and do not touch each other, and the treated water passing between them meanders.

That is, aggregates or lumps of contact filter media that spread in the lateral direction partially accumulate at certain intervals and are accumulated. These horizontal and vertical intervals are adjusted in actual operation.

With such a contact filter medium, sedimentation and floating movement of the sludge deposited on the contact filter medium can be allowed, and performances such as anaerobic digestion and sedimentation separation can be maintained without stirring.

Further, with this configuration, even if the sludge deposited on the bottom of the tank rises due to fermentation, the dish 10
e, 10f, 10g, and 10h, and only the gas in the sludge can float, and the sludge itself precipitates again, so the efficiency of anaerobic digestion, sedimentation separation, etc. can be increased, and the supernatant water in the tank is kept clean. It is.

The second anaerobic catalytic digester 20 is provided with a contact filter bed as disclosed in, for example, Japanese Patent Publication No. 1-44397.

[0032] Finally anaerobic contact digester 30, for example, spherical or polygon, the size of the contact filter media 3 to 10 mm, or filling the contact filter material having a specific surface area 600～2,000M ² per 1 m ^3.

Next, the operation of the wastewater treatment apparatus of the present invention will be described.

When the anaerobic catalytic digestion is carried out in one and two stages, the sedimentable suspended matter in the influent wastewater 1 is sufficiently removed, the suspended matter is generally less than 20 mg / l, and only the soluble organic matter remains. It will be in the state that you are doing.

Subsequently, the treated water is digested in the final anaerobic contact digestion tank 30. This final anaerobic contact digester 3
The contact filter medium filled in 0 is spherical, polygonal, etc., having a size of 3 to 10 mm, or a surface area of 6 per m ^3.
A 00~2000m ^2, is deposited immobilized anaerobic bacteria such as acid producing bacteria and methane bacteria on the surface. As a material of the contact filter medium, there is a ceramic material whose surface is made coarse and the surface area is increased so that anaerobic organisms can easily adhere thereto.

In the final anaerobic catalytic digester 30, when the treated water passes through the gap between the contact filter media, the anaerobic organisms fixed on the surface of the contact filter media efficiently decompose the organic contaminants in the treated water. ·Purify.

In order to improve the purification ability, it is more effective as the specific surface area is larger, it is desirable that there is no short circuit flow and that the treated water can sufficiently contact the surface of the contact filter medium.

That is, when the surface area of the contact filter medium is 600 m ² or less per 1 m ³ , even if the total amount of the surface area is sufficient, the influence of the short-circuit flow increases, the efficiency is reduced, and the contact filter medium is increased. It is uneconomical because it requires volume.

When the surface area is 2000 m ² or more per 1 m ³ , the gap between the contact filter media is too small, and fungi and suspended matter accumulate, and the frequency of clogging is high. Experiments have also confirmed that it is not suitable for practical use.

In the reaction of the final anaerobic catalytic digester 30, B
It can be processed to an OD of about 10 mg / l or less.

In order to provide oxygen to the anaerobic contact digested treated water, an aerobic contact oxidation tank 40 is provided, and air containing oxygen is supplied by an air supply device 61 to perform aeration treatment.

Further, sludge 24 generated in the second anaerobic catalytic digester 20, sludge 34 generated in the final anaerobic catalytic digester 30, and sludge 44 generated in the aerobic catalytic oxidizer 40.
Is returned to the first anaerobic catalytic digestion tank 10 and is anaerobically digested together with the sludge separated from the influent wastewater 1, and then discharged and disposed of as excess sludge 15.

With the organic wastewater treatment apparatus of the present invention, the following specific effects can be obtained.

A. Even with only anaerobic digestion treatment, for example, treated water having a regulated value (BOD 20 mg / l) or less from sewage (BOD about 200 mg / l) can be obtained.

B. The aerobic oxidation treatment is performed only to give dissolved oxygen to the effluent and to prevent the effluent from adversely affecting aquatic organisms. Therefore, there is no need for a conventionally used chemical or the like.

C. Power is only used to inject wastewater or treated water into each reaction tank, and finally, to supply dissolved oxygen in aerobic oxidation treatment. Since it is used thoroughly for treatment, the power of the wastewater treatment facility can be minimized.

D. From the anaerobic catalytic digester of anaerobic treatment,
Although there is a possibility that a reducing odor such as hydrogen sulfide may be generated, the anaerobic contact digestion tank has a closed structure, so that the odor can be collected and removed.

The processing system shown in the above embodiment can be modified within the scope of the present invention. For example, an anaerobic contact digestion tank is further provided in multiple stages, and the final anaerobic digestion tank is filled with a granular contact filter medium to perform an anaerobic digestion treatment. Also,
The anaerobic filter bed is raised vertically, and the first contact filter medium
The second contact filter medium, the third contact filter medium,... May be filled in a plurality of layers and treated while moving the treated water from the lower part toward the upper layer.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the structure shown in FIG.
As a result of treating municipal sewage of 00 mg / l, BOD 8 mg
/ L of treated water was obtained.

[0050]

As described above in detail, according to the present invention, the anaerobic digestion treatment of the suspended matter, BOD and sludge of the organic wastewater can be performed efficiently and with a minimum energy consumption. it can.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of the present invention.

FIG. 2 is a plan view showing an end of an anaerobic digestion tank.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Organic wastewater 10 1st anaerobic digestion tank 10b Spacer 10c Pipe 10e, 10f, 10g, 10h Plate 11, 21, 31, 41 Treatment water 15 Excess sludge 20 2nd anaerobic digestion tank 24, 34, 44 Sludge 30 Final Anaerobic digestion tank 40 Aerobic contact oxidation tank 50 Disinfection equipment 51 Discharge water 61 Air supply device

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4D003 AA02 AB02 BA02 BA04 BA06 CA01 CA04 CA07 CA08 DA09 DA18 EA01 EA20 EA24 EA30 FA10 4D040 AA04 AA23 AA31 AA34 BB52 BB57 BB82

Claims (3)

[Claims] An anaerobic contact filter in the form of a plurality of lumps or aggregates extending in the lateral direction is arranged at a constant interval in the lateral direction, and is disposed in a plurality of stages such that a part thereof is vertically overlapped at a constant interval. A first anaerobic contact digester that has been filled, a second anaerobic contact digester that has been filled with an optional contact filter, and a specific surface area of ³ to 10 mm or a specific surface area of 600 to 200 per m ^3.
A first anaerobic catalytic digestion tank filled with 0 m ² of contact filter medium, the first anaerobic catalytic digestion tank comprises a means for introducing organic wastewater, and the second anaerobic catalytic digestion tank comprises (1) means for introducing the supernatant water from the anaerobic contact digestion tank, wherein the final anaerobic contact digestion tank comprises means for introducing the supernatant water from the second anaerobic contact digestion tank; The tank is provided with means for returning sludge generated in the second anaerobic contact digestion tank and the final anaerobic contact digestion tank,
An organic wastewater treatment apparatus comprising a first anaerobic contact digestion tank and an excess sludge discharging means. 2. A plurality of anaerobic contact media in the form of a plurality of lumps or aggregates extending in the horizontal direction are arranged at regular intervals in the lateral direction, and are arranged in a plurality of stages such that a part thereof is vertically overlapped at regular intervals. a first anaerobic contact digester that is, a second anaerobic contact digesters any filter media is filled, the size of 3 to 10 mm, or a specific surface area per 1m ³ 600~2000m ²
A final anaerobic contact digestion tank filled with a contact filter medium, an aerobic contact oxidation tank provided with an aerobic contact filter bed, and a disinfection facility for disinfecting treated water, wherein the first anaerobic contact digestion tank is Means for introducing organic wastewater, the second anaerobic catalytic digester comprises means for introducing treated water from the first anaerobic catalytic digester, and the final anaerobic catalytic digester comprises a second anaerobic catalytic digester.
Equipped with a means for introducing treated water from the anaerobic contact digestion tank,
The aerobic contact oxidation tank includes a means for introducing treated water from a final anaerobic contact digestion tank and an air supply device, and the disinfection facility includes means for introducing treated water from the aerobic contact oxidation tank, The first anaerobic catalytic digester has a means for returning sludge generated in the second anaerobic catalytic digester, the final anaerobic catalytic digester and the aerobic catalytic oxidizer, and the first anaerobic catalytic digester has a surplus. An organic wastewater treatment device comprising sludge discharge means. 3. An apparatus for treating organic wastewater, wherein a plurality of anaerobic contact filter media are respectively mounted on a support member.