JP3242473B2 - Ultra deep aeration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-deep aeration method.

[0002]

2. Description of the Related Art Conventionally, a deep aeration method (Deep Shaft method)
Is an activated sludge method using a vertical shaft having a depth of 40 to 150 m as an aeration tank as disclosed in Japanese Patent Publication No. 61-39118, for example. It is used for In the ultra-deep aeration method, the depth of the aeration tank is deep, so that the oxygen transfer rate into the liquid is increased using water pressure, and the BOD component is treated at a high rate.

[0003] The features of the ultra-deep aeration method as a treatment facility are as follows:
This is to reduce the area of the facility. At present, in industrial wastewater treatment facilities, particularly in the food industry, the pharmaceutical industry, and the chemical industry, there is a strong need to treat high-concentration wastewater in a small space. The ultra-deep aeration method meets this need, but further space saving and high efficiency are expected.

In order to achieve space saving, it is necessary to use B
It is necessary to improve the OD component decomposition ability. On the other hand, for BOD treatment of sewage and organic industrial wastewater, it is known to use microorganisms (immobilized microorganisms) immobilized on polyacrylamide gel instead of activated sludge.

It is known that a treatment method in which immobilized microorganisms are filled in an aeration tank can perform a stable treatment with a higher load than the conventional activated sludge method (Abstracts of the 43rd Annual Meeting of the Japan Society of Civil Engineers). Part 2, 990, (1988)).

[0006]

As described above, the ultra-deep aeration method has a great feature that the dissolved oxygen concentration in the tank is increased because a deep aeration tank is used (FIG. 5 ).

However, it is difficult to say that this feature is fully utilized in a conventional ultra-deep aeration plant, and the volume load is high and the BOD is designed to be ⁵ kg / m ³ days. On the other hand, when organic wastewater is treated using immobilized microorganisms, as shown in FIG. 6 , the BOD volume load (BODKg / m
^{When 3} days is 4 kg / m ³ days or more, good treatment cannot be performed only by blowing normal air, and high-load treatment cannot be performed unless oxygen gas is blown and dissolved oxygen is increased (" Wastewater '' Vol.27 No.10 P.54, P.56 (1985)
reference). That is, it is said that the immobilized microorganism has difficulty in diffusing the substrate and dissolved oxygen into the inside of the carrier.

[0008] This indicates that immobilized microorganisms may exhibit higher decomposition treatment capacity in a state of high dissolved oxygen. Therefore, the present inventor has found that a new ultra-deep aeration method that can be operated at a high volume load can be achieved by applying immobilized microorganisms as a medium for removing BOD components in wastewater under the high dissolved oxygen of ultra-deep aeration. I found it.

[0009] The present invention has been made based on such knowledge, and an object thereof is to replace the activated sludge microorganisms involved in the decomposition of the BOD component by the conventional ultra-deep aeration method, and to convert the immobilized microorganisms to the decomposition of the BOD component. It is an object of the present invention to provide an ultra-deep aeration method which can be applied to a removal medium, can process wastewater having a high concentration in a smaller space, and can make return sludge unnecessary.

[0010]

According to a first aspect of the present invention, there is provided an ultra-deep aeration method in which flowing water of an upflow pipe portion is provided inside a vertically elongated shaft.
A vertically long pipe provided with an opening leading to the downflow pipe
A double pipe structure and a vertical pipe above the opening
An annular obstruction that slopes downhill towards the long shaft
A solid-liquid separation unit is provided between the vertical shaft and the baffle plate
To form an ultra-deep aeration tank,
After filling the tank with immobilized microorganisms, raw water flows in and air
To make the downflow pipe part a downflow and the upflow pipe
Part is ascending flow, and the immobilized microorganisms
Oxidative degradation as a substrate for microorganisms
Solid-liquid separation between the vertically elongated shaft and the baffle plate
Separates the immobilized microorganisms and treated water in the
The ascending flow pipe section provided in the inner vertical pipe is used for
Flowing water of the rising pipe section into this elongated pipe from the opening leading to the section
Is settled together with the downflow along with the introduction of the water, and the treated water is caused to flow into the downflow pipe from the opening and a part of the water is drained.

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[Action] Te is at in claim 1, firstly, to fill the immobilized microorganism in the elongated shaft. Next, raw water flows into the vertical shaft, and air is supplied into the downflow pipe section and the upflow pipe section of the vertical shaft, so that the downflow pipe section becomes the downflow and the upflow pipe section becomes Is formed as a circulating flow.

Thus, the immobilized microorganisms can be caused to flow in the longitudinal shaft together with the raw water. During this flow, the microorganisms adhere to the immobilized microorganisms, and the microorganisms undergo oxidative degradation as a substrate for the microorganisms.

The high oxidative decomposition treatment is that the immobilized microorganisms repeatedly flow under different pressures between a high pressure state (the bottom of the shaft) and a reduced pressure state (a reduced pressure state compared to the bottom of the shaft, in other words, a normal pressure state). Is caused by This is because the immobilized microorganisms undergo oxidative degradation while taking oxygen and substrate into the microbial layer in the process of flowing down to the bottom of the shaft, and then the carbon dioxide gas produced as a result of oxidative degradation in the process of rising by upward flow (decompression process) An environment that enables effective microbial metabolism by releasing ammonia gas and the like is provided.

Then, the immobilized microorganisms and the treated water are separated in a solid-liquid separation section between the vertically long shaft and the baffle plate. The separated immobilized microorganisms are sedimented together with a downward flow into an elongate shaft from an opening provided in the inner elongate tube. On the other hand, the treated water flows into the downflow pipe from the opening and a part of the treated water is drained.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a basic system of the ultra-deep aeration method according to the present invention.

In FIG. 1, after the wastewater (object to be treated) is once put into the regulating tank 1, the BOD is filled in the ultra-deep aeration tank 2 by the immobilized microorganisms filled in the ultra-deep aeration tank 2. The components are decomposed and removed with high efficiency, solid-liquid separation of immobilized microorganisms and treated water is performed, treated water is discharged or sent to an advanced treatment step, and excess sludge is stored in the storage tank 3.

Next, one embodiment of the ultra-deep aeration method according to claim 1 will be described in detail with reference to FIGS. In the drawing, reference numeral 10 denotes a vertically long shaft having no divergent portion at the top.

This vertically long shaft 10 has a length of 40 to 150
By attaching the vertically long pipe 30 in the length direction of the vertically elongated bottomed pipe body 11 and forming the communication part 14 in the bottom 13, a downflow pipe section 58 and an ascending flow pipe section 57 are provided. .

The vertically elongated shaft 10 has a downflow pipe section.
A nozzle 18 for jetting air to the nozzle 58 and the rising pipe portion 57 ,
19 are provided. Each nozzle 18, 19 communicates with a compressor 17.

The jet port 18a of the nozzle 18 is directed downward so that the downflow pipe portion 58 is caused to flow downward by the supplied air, and the jet port 19a of the nozzle 19 is
The supplied air is directed upward so that the upflow pipe portion 57 has an upflow.

The inner tube 30 is located below the surface of the water,
An opening 55 for guiding running water to the downflow pipe section is provided to form a circulating flow.
Has formed.

Above the opening 55, there is a slanted annular obstacle.
A baffle plate 53 is provided, and a vertically long shaft 10 and a baffle plate 5 are provided.
A solid-liquid separation portion 56 is formed between the solid-liquid separating portion 56 and the solid-liquid separating portion 56. Portrait
Fixed at solid-liquid separation section 56 between shaft 10 and baffle plate 53
Microorganisms and treated water are separated by treated water collecting weir 54a.
The treated water is collected in the treated water outlet pipe 54. 5 and 6
In this case, the baffle plate 53 is made of a material such as steel, resin, or fiber.
Either may be used. The shape of the baffle plate 53 is plate-like,
Immobilized microorganisms pass through, such as slabs, wire mesh,
Any shape that does not have any shape is possible. Also, the treated water collecting weir 54a
May be all around the vertical shaft 10 or a part thereof.

Next, a method of treating waste water using the thus constructed super deep aeration apparatus will be described. First, a vertically long shaft 10 is filled with immobilized microorganisms. Next, raw water flows into the vertically elongated shaft 10, and air is supplied from the nozzles 18 and 19 into the descending flow tube portion 58 and the ascending flow tube portion 57 of the vertically elongated shaft 10. 5
A circulating flow is formed with 8 as the downflow and upflow pipe 57 as the upflow.

The raw water moving down the downflow pipe section 58 as a downflow turns at the bottom 13 of the vertically elongated shaft 10 into an upward flow, rises to the upper portion of the vertically elongated shaft 10, and is baffled.
Just before 53, the water circulates again from the opening 55 to the downflow pipe 58 . Also, the solid-liquid between the vertically elongated shaft 10 and the baffle plate 53
The immobilized microorganisms and the treated water are separated by the separation unit 56 and treated.
The treated water is collected in the treated water outlet pipe 54 by the water collecting weir 54a.
Can be

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

As described in the foregoing, according to the ultra-deep aeration according to claim 1, since the to circulate immobilized microorganism with raw water in ultra deep aeration tank, immobilized microorganisms ultra deep aeration tank , It is possible to achieve a high-load treatment with a BOD volume load of 4 kg / m ³ days or more.

That is, BOD volume load of 4 kg / m ^{3 in} the conventional method
In order to achieve high-load processing for more than a day,
According to the ultra-deep aeration method according to claim 1 , it is necessary to perform the operation of halving the filling rate and supplying pure oxygen. I could do without it. Also, since the filling rate is as small as 20%, solid-liquid separation becomes easy.

[0047] Further, according to the ultra-deep aeration according to claim 1, immobilized microorganism with treated water from the opening provided below the water surface below the open end of the upflow tube portion downflow by the flow velocity reduction Since it moves toward the pipe and falls naturally, it does not move to the solid-liquid separation region. Therefore, even though the system circulates the treated water and the immobilized microorganisms at the same time, there is no possibility that the solid-liquid separation treatment is hindered by the immobilized microorganisms in the head tank.

[Brief description of the drawings]

FIG. 1 is a block diagram of a basic system of an ultra-deep aeration method according to the present invention.

FIG. 2 is a sectional view of an apparatus used in one embodiment of the ultra-deep aeration method according to claim 1;

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a schematic view of an oxidative decomposition treatment under different pressure conditions.

FIG. 5 is a graph showing a relationship between water depth and dissolved oxygen.

FIG. 6 shows a conventional treatment method using immobilized microorganisms.
A graph showing the relationship between BOD volume load and treated water BOD.
is there.

[Explanation of symbols]

Reference Signs List 10 Vertical shaft 17 Compressor 18, 19 Nozzle 55 opening 57 Upflow pipe 58 Downflow pipe

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsufumi Kawashima 2-5-14 Minamisuna, Koto-ku, Tokyo Inside the Technical Research Institute, Takenaka Corporation (72) Inventor Kohei Kagami 8-2-1-1, Ginza, Chuo-ku, Tokyo No. Takenaka Corporation Tokyo Main Branch (72) Inventor Kenji Odawara 8-21-1, Ginza, Chuo-ku, Tokyo Tokyo Inside (72) Inventor Yukio Tsujimoto 8-21 Ginza, Chuo-ku, Tokyo No. 1 Inside Takenaka Corporation Tokyo Main Store (56) References JP-A-4-338293 (JP, A) JP-A-4-354597 (JP, A) JP-A-2-135196 (JP, A) 48-5936 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 3/00-3/34

Claims (1)

(57) [Claims] 1. An upflow pipe section inside a vertically elongated shaft.
Equipped with a vertically long pipe with an opening to guide running water to the downflow pipe
Into a double pipe structure, and a vertically long pipe above the opening.
From the bottom to the vertical shaft
Solid liquid between the vertical shaft and the baffle
An ultra-deep aeration tank formed by forming a separation section is formed.
Raw water flows in after immobilized microorganisms are filled in the bed aeration tank
And supply air to make the downcomer pipe downflow.
The ascending pipe is used as ascending flow, and immobilized microorganisms flow along with raw water.
Acid as a substrate for microorganisms
Chemical decomposition treatment, between the vertical shaft and the baffle
Separation of immobilized microorganisms and treated water in the solid-liquid separation section and immobilization
Flowing water from the rising pipe section where the
Ascending flow pipe into this elongated pipe from the opening leading to the downflow pipe section
A super deep aeration method characterized by causing sedimentation with a descending flow along with the introduction of running water in a section, allowing treated water to flow into a descending pipe section through an opening, and draining a part of the treated water.