JPH08197078A - Biological sewage treating device - Google Patents

Abstract

PURPOSE: To make a settling tank of a biological sewage treating device compact by setting an organism immobilizing carrier in, an aeration tank or in an anaerobic tank and throwing in a granular solid material having a specified grain diameter. CONSTITUTION: A granular solid material 4 is thrown in an aeration part 1, an immobilized organism immobilizing carrier 3 is set at an intermediate height of the aeration part 1. Raw water 5 is introduced from the lower part of the aeration part 1, and air 8 is blown in from the lower part of the aeration part 1. Consequently, the org. component in the raw water is brought into contact with activated sludge, and the org. matter is decomposed and removed. The activated sludge is deposited on the carrier 3, and the amt. of immobilized activated sludge is increased. Accordingly, even if the concn. of activated sludge is lowered in a fluidized region, the concn. of the activated sludge effective in the entire treatment of the aeration part 1 is maintained at the same concn. as before. Further, the settling velocity of activated sludge is increased and the water surface area of a settling part 2 is decreased by throwing in the granular solid material 4 having <=100μm grain diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological sewage treatment apparatus for treating organic substances and inorganic substances such as sewage and industrial wastewater.

[0002]

2. Description of the Related Art In the biological treatment method for wastewater containing a biological carrier, only one type of biological carrier has been used from the viewpoint of increasing the concentration of microorganisms in the reaction tank or increasing the sedimentation rate of sludge.

In the immobilized microorganism method, biological immobilization carriers such as string-shaped carriers, ceramics carriers, and honeycomb-shaped carriers are installed in the reaction tank to increase the concentration of microorganisms in the reaction tank and to pursue compactness of the reaction tank. I've been

For example, in Japanese Unexamined Patent Publication No. 63-252591, as shown in FIG. 6, in an aerobic method (multistage type) or an anaerobic-aerobic method, a sedimentation tank is a biological tank such as an aerobic tank or an anaerobic layer. It is characterized in that it is installed in the latter stage of the reaction tank and the sludge collected by the gravity settling method is returned to the reaction tank to make the treatment equipment compact and obtain treated water with high clarity.

On the other hand, in Japanese Unexamined Patent Publication (Kokai) No. 3-178395, in the treatment of activated sludge, the aeration part and the sedimentation part are integrated, and the aeration part (see FIG. 7) of the high-speed aeration sedimentation basin has a particle size of 100 μm or less. As a biological carrier, a large number of granular solids (carriers) are incorporated into the activated sludge flocs to increase the specific gravity of the flocs (anchor effect), thereby promoting solid-liquid separation, and the activated sludge concentration in the aeration section. I am trying to increase. As a result, it is possible to make the aeration section compact and the final settling tank compact.

[0006]

However, Japanese Patent Laid-Open No. 63-252591 and Japanese Patent Laid-Open No. 3-1 have been exemplified above.
In the conventional biological treatment method of wastewater such as Japanese Patent No. 78395, it is indispensable to have a large water separation area, and the settling tank is inevitably large.

Therefore, an object of the present invention is to provide a biological sewage treatment apparatus in which a sedimentation tank is made compact without requiring a large water separation area.

[0008]

The present invention is characterized in that an aeration tank (aerobic tank) or an anaerobic tank is charged with granular solids having a particle size of 100 μm or less and a biological immobilization carrier is installed. This is a biological sewage treatment device.

As the biological treatment device, a standard activated sludge treatment device in which an aeration tank and a sedimentation tank are separated or a high-speed aeration sedimentation tank in which the aeration tank and the sedimentation tank are integrated may be used. An apparatus having an aerobic activated sludge treatment process may be used.

As the biological immobilization carrier, a non-fluid type biological immobilization consisting of a net-shaped immobilization carrier, a string immobilization carrier, a ceramic carrier, a honeycomb carrier, a rotating disk, a corrugated plate carrier and a flat plate carrier. It is preferably a carrier.

[0011]

In the present invention, the biological immobilization carrier is installed in the aeration tank (aerobic tank) or the anaerobic tank of the biological sewage treatment apparatus, and granular solid matter having a particle size of 100 μm or less is charged.

When the bio-immobilized carrier is installed in the reaction tank, the activated sludge adheres to the bio-immobilized carrier and the concentration of the activated sludge in the solidified carrier region can be increased. Therefore, even if the activated sludge concentration in the area other than the immobilized carrier (hereinafter referred to as the fluidized area) is reduced,
The activated sludge concentration that is effective for treating the entire reaction tank can be maintained at the same level as in the prior art. That is, the biological reaction tank can have a biological treatment capacity equivalent to that of the prior art.

On the other hand, when the activated sludge in the fluidized area is sent to the settling tank, the settling speed of the activated sludge is higher than that in the conventional case because the activated sludge concentration is lowered. Furthermore, in the present invention, by adding the granular solid matter into the reaction tank, the granular solid matter is incorporated into the activated sludge flocs,
Increase the specific gravity of the flock. Therefore, due to the combined effect of the decrease in the activated sludge concentration in the above-mentioned flow region and the incorporation of the particulate solids into the flocs, the sedimentation rate of the activated sludge in the settling tank is further increased, and the solid-liquid separation property is dramatically improved. be able to. As a result, a large water separation area as in the prior art is not necessary, and the sedimentation part can be made more compact than before by reducing the water separation area.

The present invention will be described in more detail below. First, the biosolidified carrier can be classified into a non-fluid type and a fluid type. As the non-fluid type, the net-shaped fixed carrier and the string-shaped fixed carrier include a ceramics carrier, a honeycomb-shaped carrier, a rotating disk, a corrugated plate carrier, a flat plate carrier and the like. In particular, as the non-fluid type, a net-like or string-like immobilizing carrier is preferable because it is relatively inexpensive and is less likely to be clogged. Examples of the fluid type include sponge-like carriers and fibrous carriers. In the present invention,
It may be a non-fluid type or a fluid type, and may be appropriately selected and determined. However, in the case of applying the fluid type, it is necessary to install a screen or the like on the upper part of the reaction tank so that the carrier does not flow out of the reaction tank. With respect to the area of the bio-immobilized carrier occupying in the reaction tank, for example, a cord-shaped carrier is used as the non-fluidic bio-immobilized carrier at a packing rate of 150 m / m ^3.
When it is installed in the aeration tank, the volume ratio is preferably 20% or more.

Next, the granular solid matter must have a particle size of 100 μm or less in order to be easily taken into the activated sludge flocs. The particle size is preferably 40 μm or less and has a large specific gravity.

As the granular solid material, any material such as zeolite and coke powder can be used, but fine powder of granulated blast furnace slag is very suitable. The amount of the particulate solid matter added is not particularly limited, but is preferably 0.2% or more in order to further exert the effects of the present invention.

Furthermore, the biological sewage treatment apparatus of the present invention can be applied to various conventionally-used sewage treatment methods. Examples include a high-speed aeration sedimentation tank that integrates aeration and sedimentation, a standard activated sludge method in which an aeration tank and a sedimentation tank are separated, and an anaerobic-aerobic activated sludge method that continuously performs anaerobic treatment and aerobic treatment. be able to.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is an example in which the apparatus of the present invention is applied to a high-speed aeration settling tank in which an aeration tank and a settling tank are integrated. The solid particles 4 are put into the aeration section 1 and the non-fluidic organism immobilization carrier 3 is installed at an intermediate height of the aeration section 1. Raw water 5 is sent from the lower part of the aeration unit 1, and
By blowing the air 8 from the lower part of the aeration unit 1, the organic component in the raw water and the activated sludge are brought into contact with each other to decompose and remove the organic substance. Activated sludge is a non-fluid type biological immobilization carrier 3
It is possible to increase the amount of the activated sludge fixed by being attached to the. Therefore, even if the concentration of the activated sludge in the flow region is reduced, the concentration of the activated sludge effective for the treatment of the entire aeration section can be maintained equal to that of the conventional technique. That is, the aeration unit 1 can have a processing capacity equivalent to that of the conventional technique. Next, the low-concentration activated sludge in the flow region is sent to the settling section 2. In the settling unit 2, the sludge concentration is lowered, so that the settling speed of the activated sludge can be increased. On the other hand, by introducing the granular solids 4 into the aeration unit 1, since the granular solids 4 are taken into the activated sludge and the specific gravity of the sludge flocs is increased, the sedimentation speed of the activated sludge in the sedimentation unit 2 is increased. It can be increased even more. And as a result,
The water surface area of the precipitation part 2 can be reduced, and the precipitation part can be made compact.

Next, the effect of the present invention in FIG. 1 will be shown by an experimental result. For example, the OFR (surface area load factor) of the sedimentation part is shown for the case where the fine powder of granulated blast furnace slag is adopted as the granular solid 4 and the string-like carrier is adopted as the non-fluidic biological immobilization carrier 3 and when it is not adopted. Table 1 shows a comparison. Table 1 lists processing specifications. As is clear from this table, by installing the bio-immobilized carrier,
The activated sludge concentration in the fluidized zone can be reduced without lowering the effective aeration zone activated sludge concentration (average) for treatment, and the sedimentation rate of the activated sludge in the sedimentation zone can be increased twice or more compared to the conventional method. You can As a result, the settling section can be made significantly compact.

[0020]

[Table 1]

FIG. 2 shows another embodiment of the present invention in which the apparatus of the present invention is applied to a treatment system in which an aeration tank and a precipitation tank are separated. A non-fluidized immobilization carrier 3 is installed in the middle part of the aeration tank 1, and the granular solid matter 4 is introduced into the tank from above the aeration tank 1. The raw water 5 is sent from the lower part of the aeration tank 1 into the tank, but at the same time, the air 8 is also blown from the lower part of the tank. The subsequent treatment steps are as already described in FIG. 1, and the settling tank 2 can be made more compact than before because the settling speed of the activated sludge in the settling tank 2 is increased.

FIG. 3 shows another embodiment of the present invention in which a fluid-type biological immobilization carrier is applied in place of the non-fluid-type biological immobilization carrier in FIG. In this example to which the fluid-type biologically immobilized carrier is applied, in order to prevent the carrier from flowing out of the aeration tank, it is necessary to provide an outflow prevention tool such as the screen 11 above the tank.

FIG. 4 shows another embodiment to which the present invention is applied in the anaerobic-aerobic activated sludge method. A non-fluidic organism immobilization carrier is installed in the middle part of the anaerobic tank 12, and the granular solid matter 4 is charged from the upper part of the anaerobic tank 12. The raw water 5 is sent from the lower part of the anaerobic tank 12, but a stirrer 13 is provided at the lower part of the tank to increase the number of contact between the raw water and the anaerobic sludge,
Improves processability. The water treated in the anaerobic tank 12 is then sent into the tank from the lower part of the aerobic tank 1. Aerobic tank 1
Also, a non-fluid type biological immobilization carrier is installed, and air 8 is sent from the lower part of the tank. The sludge concentration of the sludge mixture liquid coming out of the aerobic tank 1 is smaller than the average concentration in the aerobic tank 1, and the granular solids 4 are taken into the activated sludge, and the specific gravity of the sludge flocs is large. The sedimentation speed of the activated sludge in the next settling tank 2 can be increased, and the settling tank 2 can be made compact.

FIG. 5 shows another embodiment in which a fluid-type biological immobilization carrier is applied instead of the non-fluid-type biological immobilization carrier in FIG. In the figure, the gas generated at the time of anaerobic treatment is fed from the lower part of the anaerobic tank 12 through the gas circulation blower 14 to flow the fluidized organism-immobilized carrier.

[0025]

INDUSTRIAL APPLICABILITY According to the present invention, a non-fluid-type biological immobilization carrier is installed in a biological reaction tank or a fluid-type biological immobilization carrier is added to change the total amount of activated sludge effective for treatment in the reaction tank. Without reducing the concentration of suspended activated sludge, and adding granular solid matter having a particle size of 100 μm or less,
The specific gravity is increased by being incorporated into the floating activated sludge flocs, and the sedimentation speed of the floating activated sludge flocs is dramatically increased. As a result, a large water separation area is unnecessary, and the precipitation part can be made more compact.

[Brief description of drawings]

FIG. 1 shows an example in which the sewage treatment apparatus of the present invention is applied to a high-speed aeration sedimentation tank in which an aeration tank and a sedimentation tank are integrated. A non-fluid type is used as the biological immobilization carrier.

FIG. 2 shows an example in which the sewage treatment apparatus of the present invention is applied to a standard activated sludge system in which an aeration tank and a sedimentation tank are separated. A non-fluid type is used as the biological immobilization carrier.

FIG. 3 shows an example in which a fluid-type biological immobilization carrier is applied instead of the non-fluid-type biological immobilization carrier of FIG.

FIG. 4 shows an example in which the sewage treatment apparatus of the present invention is applied to an anaerobic-aerobic activated sludge method. In addition, a non-fluid type is adopted as the biological immobilization carrier.

5 shows an example in which a fluid-type biological immobilization carrier is applied instead of the non-fluid-type biological immobilization carrier of FIG.

FIG. 6 is an explanatory diagram showing a conventional biological treatment method.

FIG. 7 is a cross-sectional view showing an aeration section of a conventional high-speed aeration sedimentation tank.

[Explanation of symbols]

 1 Aeration section (aeration tank, aerobic tank) 2 Precipitation section (sedimentation tank) 3 Non-fluid type biological immobilization carrier 4 Granular solid matter 5 Raw water 6 Treated water 7 Sludge extraction 8 Air 9 Return sludge 10 Fluid type biological immobilization carrier 11 Screen 12 Anaerobic Tank 13 Stirrer 14 Gas Circulation Blower 15 Sludge Mixture

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Kamori 2-6-3 Otemachi, Chiyoda-ku, Tokyo Shin Nippon Steel Corporation

Claims (6)

[Claims] 1. A biological sewage treatment apparatus characterized in that an aeration tank or an anaerobic tank is charged with granular solid matter having a particle size of 100 μm or less and a biological immobilization carrier is installed. 2. The biological treatment apparatus according to claim 1, wherein a high-speed aeration sedimentation tank is used as the biological treatment apparatus. 3. The biological treatment apparatus according to claim 1, wherein a standard activated sludge treatment apparatus is used as the biological treatment apparatus. 4. The biological treatment apparatus according to claim 1, wherein the biological treatment apparatus has an anaerobic-aerobic activated sludge treatment process. 5. A non-fluidic bio-immobilized carrier, wherein the bio-immobilized carrier comprises a group of a net-like immobilized carrier, a string-like immobilized carrier, a ceramic carrier, a honeycomb carrier, a rotating disk, a corrugated plate carrier and a flat carrier. The biological sewage treatment apparatus according to claim 1, wherein the biological sewage treatment apparatus is any one of the above. 6. The biological sewage treatment apparatus according to claim 2, wherein the bio-immobilized carrier is a sponge-like carrier or a fibrous carrier fluidized bio-immobilized carrier. .