JPH11114591A - Fluidized bed type sewage treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact high pollutant load treating device of a single tank and a continuous treatment system. SOLUTION: A vertically long treating tank 2 is provided with a partition plate 3, by which the treating tank 2 is vertically segmented to form an aeration tank section 5 and a settling tank section 4. The partition plate 3 is provided with functions as the ceiling surface of the aeration tank section 5 and the base of the settling tank section 4. The sewage to be treated which is subjected to an aeration treatment in the aeration tank section 5 is directly transferred through the partition plate 3 to the settling tank section 4. The flocs growing and settling in the settling tank section 4 return to the aeration tank section 5 where the flocs grow further and settle. The flocs are then discharged outside the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed type sewage treatment apparatus, and more particularly to a treatment tank which is divided into upper and lower parts by a partitioning machine to form an aeration tank section and a sedimentation tank section so that the partitioning board can be raised and lowered. And the volume ratio of the two can be changed, and the sewage to be treated directly enters the sedimentation tank from the aeration tank, and flocs that grow and settle in the sedimentation tank return to the aeration tank. Is what you do.

[0002]

2. Description of the Related Art Wastewater containing organic wastes such as domestic wastewater and industrial wastewater is often purified by a biological treatment method or a sewage treatment apparatus based on a coagulation sedimentation method. A sewage treatment apparatus for purifying sewage having a normal concentration by a biological treatment method is, for example, as shown in FIG.
11 and a pH adjustment tank 12, an aeration tank 13, a reaction tank 14, a coagulation tank 15, a sedimentation tank 16, a disinfection tank 17, a sand filtration tank 18, a treatment water tank 19, and the like. A prescribed purification process is added while transferring, and the purified water is once treated in a treatment tank.
Stored in 19 and released. The raw water adjusting tank 11 is provided with a sand settling tank and a screen tank. The water to be treated introduced into this apparatus is first introduced into a sand settling tank to remove sedimentable solids, and then this is set in a screen tank. It is transferred to remove floating solids and stored in the raw water adjusting tank 11.
Next, the water to be treated is pumped up by a water supply pump and quantitatively sent to the pH adjusting tank 12, and if necessary, an alkaline aqueous solution or an acidic aqueous solution is added thereto to adjust the water to be treated to a predetermined pH. Then, the microorganisms are made to flow into the aeration tank 13 of the aeration system, and foamy air is sent therein to dissolve oxygen in the liquid, thereby activating the microorganisms and activating the proliferation, thereby promoting the decomposition of the wastewater components. The water to be treated, in which the microorganisms have sufficiently grown, is transferred to the reaction tank 14 and an aqueous solution of an inorganic coagulant is added thereto to form fine flocs in the liquid. The floc is greatly grown by adding an aqueous solution of the agent. Subsequently, the to-be-treated water is allowed to flow into the sedimentation tank 16, and the floc is settled and removed while being settled. Then, the almost-clean water to be treated is transferred to a disinfecting tank 17, to which an aqueous disinfectant solution is added for disinfection, and then sent to a sand filtration tank 18 to leave fine suspended solids remaining in the liquid. Is filtered to complete the purification process, and the purified water is temporarily stored in the treated water tank 19 and discharged out of the system.

[0003]

In the conventional activated sludge treatment apparatus, the BOD of the wastewater to be treated has a relatively low concentration of about 1000 mg / l or less. With the increase, appropriate environmental measures have become a major issue, and the eutrophication phenomenon of lakes and marshes and rivers due to domestic wastewater has become a problem. In addition, the amount of industrial wastewater is increasing year by year, and the concentration of the wastewater is gradually increasing. In addition, there are many treatment apparatuses whose renewal time has come due to aging of the equipment. In addition, high-concentration sewage that cannot be treated by the conventional sewage treatment apparatus is generated suddenly or intermittently. For these reasons, in recent years, there has been a demand for the development of a sewage treatment apparatus capable of withstanding a high pollution load as a pretreatment apparatus of the sewage treatment apparatus. The conventional continuous activated sludge treatment method comprises an aeration tank and a sedimentation tank. Sewage is continuously injected from one of the aeration tanks, the treated water to be treated is taken out and transferred to the sedimentation tank, where sedimentation and separation are performed. However, this method has a problem that the apparatus is large and the equipment cost is high. In addition, since it is not possible to effectively treat high polluted load wastewater, a larger apparatus is required when treating such wastewater. The batch type sludge treatment method is
In a single reactor, the wastewater is treated by performing a series of operations including injection, aeration, precipitation, and discharge of the wastewater.
It is difficult to treat high pollution load sewage. In addition, there is a problem that if the activated sludge expands, the treatment becomes impossible and the treatment cannot be continued. An object of the present invention is to provide a compact, high-contamination load treatment apparatus which is a single tank and of a continuous treatment type.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a partition plate is provided in a vertically long processing tank, whereby the processing tank is divided into upper and lower parts to form an aeration tank part and a sedimentation tank part. Has the function of the ceiling surface of the aeration tank part and the bottom surface of the sedimentation tank part, and the sewage to be treated aerated in the aeration tank part moves directly to the sedimentation tank part through the partition plate and grows in the sedimentation tank part. The above-mentioned object is achieved by means for arranging the floc that settles down and returns to the aeration tank section, and the treated water is discharged out of the machine. The partitioning plate can be formed so as to be able to move up and down so that the volume ratio between the aeration tank section and the precipitation tank section can be adjusted according to the properties of the sewage to be treated.

[0005]

According to the present invention, a partition plate is provided in a vertically long processing tank, whereby the processing tank is divided into upper and lower parts to form an aeration tank part and a sedimentation tank part. There is no need for a facility for feeding treated wastewater and a facility for returning concentrated sludge from the sedimentation tank to the aeration tank. When the flocs grown in the sedimentation tank return to the aeration tank, a floc circulation path is formed between the aeration tank and the sedimentation tank, and when the flocs have grown sufficiently, they are discharged out of the machine. Different.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fluidized bed type sewage treatment apparatus according to the present invention will be specifically described based on the illustrated embodiment. Symbol 2 in the figure
Is a processing tank. The processing tank 2 is a vertical cylindrical tank having a height corresponding to the sum of the depth of the aeration tank and the depth of the sedimentation tank. The lower part functions as an aeration tank, and the upper part functions as a precipitation tank. The aeration tank section 5 is of a fluidized bed type in this embodiment. An inner cylinder 51 is provided on the center line, and an inverted conical flow distributor 53 is provided above the inner cylinder 51. Further, a raw water supply pipe 52 is opened in the inner cylinder 51, and a predetermined amount of the sewage to be treated is injected into the raw water supply pipe 52, and a bubble generating nozzle 54 is provided below the raw water supply pipe 52, so that air is supplied. When the aerated tank section 5 is filled with the sewage to be treated and the bubbles are ejected from the bubble generation nozzle 54, the bubbles are mixed with the sewage to be treated in the inner cylinder 51. At the same time, an upward flow due to bubbles is generated in the inner cylinder 51. Due to this upward flow, the sewage to be treated in the inner cylinder 51 rises, and eventually reaches the distribution plate 53 and goes outward, descends outside the inner cylinder 51, returns to the lower part of the inner cylinder 51, and returns to the inner cylinder 51 again. Rise the inner cylinder
A flow circulation path is formed between the inside and outside of 51. Then, the sewage to be treated is agitated in the aeration tank unit 5 by the circulating flow, and the sewage is sufficiently brought into contact with the bubbles to promote the purification action. Further, in this embodiment, an outlet 55 for the sewage to be treated is attached to the upper part of the aeration tank part 5, and an inlet 56 is attached to the lower part thereof, and both are connected by a circulation pump (not shown). Thus, a part of the sewage to be treated in the upper part of the aeration tank unit 5 is taken out and ejected from the lower part thereof, thereby promoting the circulation and stirring of the sewage to be treated.
The partitioning board 3 has a function of a ceiling surface of the aeration tank 5 and a bottom of the sedimentation tank 4, and serves as an ascending passage for the sewage to be treated and air from the aeration tank 5 to the precipitation tank 4. In the center, the distribution pipe 31 and the air exhaust pipe 35 are attached,
Thus, the aeration tank section 5 and the precipitation tank section 4 are continuous with each other, and the air separated from the sewage to be treated in the aeration tank section 5 passes therethrough and is discharged outside the machine. Processing tank 2
A V-notch plate 21 is attached to the upper edge of the sewage. The sewage to be treated, which has been purified in the aeration tank 5, is distributed in an amount corresponding to the amount of sewage to be newly injected into the aeration tank 5. In the sedimentation tank section 4, the treated sewage further purified in the sedimentation tank section 4 is reduced by the amount of the sewage newly introduced from the aeration tank section 5. As much as possible, it overflows out of the tank through the V-notch, and the discharge pipe 6
It is to be discharged through. In the sedimentation tank section 4, a covering pipe 32 is provided at a position surrounding the circulation pipe 31, and the air entering the precipitation tank section 4 through the circulation pipe 31 is diffused outside the apparatus without stirring the wastewater to be treated therein. As well as
The to-be-processed sewage which flows in flows out from the lower end of the covering pipe 32 along the partition board 3, and it does not stir the to-be-processed sewage in this. In the sedimentation tank section 4, minute flocs in the sewage to be treated gradually grow and eventually settle.
This floc is returned to the aeration tank section 5 through a gap formed between the outer peripheral edge of the partition plate 3 and the inner wall surface of the processing tank 2, where it further grows and precipitates, and at the lower end of the processing tank 2. Excess sludge is taken out from the attached drawing pipe 7 and discarded. In this embodiment, the partitioning plate 3 is formed in an umbrella shape so that the floc that has settled thereon can easily descend toward the outer peripheral edge, and a scraping plate 34 is attached.
Further, the floc that has settled down is surely dropped into the aeration tank 5 by being slowly rotated by the motor 33. The machine frame 8 is provided with an elevating frame 9 above the processing tank 2, and the partitioning machine 3 is attached to the elevating frame 9. The volume ratio between the section 5 and the settling tank section 4 can be appropriately selected.

When purifying the sewage to be treated, the height of the partition 3 is first adjusted in accordance with the properties of the sewage to be treated, and the aeration tank section 5 and the sedimentation tank section 4 are set to an appropriate volume ratio.
That is, when the concentration of the sewage to be treated is low and the required aeration time is short, the volume of the aeration tank unit 5 is reduced, and the amount of new sewage to be treated per unit time is increased. This is to shorten the residence time of the sewage to be treated in the section 5 and increase the capacity of the settling tank section 4 to increase its treatment capacity. When the sewage to be treated has a high concentration and requires a long aeration time, By increasing the volume of the aeration tank 5, the residence time of the wastewater to be treated in the aeration tank 5 is extended.
Then, the tank is filled with the sewage to be treated, and bubbles are ejected from the bubble generation nozzle 54 while injecting a predetermined amount of the sewage to be treated from the raw water supply pipe 52. In the aeration tank part 5, the circulating flow of the sewage to be treated rises inside the inner cylinder 51 and descends outside the inner cylinder 51,
This is agitated and mixed with air bubbles, whereby the growth of microorganisms is activated and organic components are decomposed. Therefore, when the concentration of the sewage to be treated is low and the required aeration time is short, the sewage is adjusted to stay in the aeration tank section 5 for about 1/4 to 1 day. When the time is long, it is adjusted so as to stay for about 2 to 4 days, and the bubbles generate a circulating flow of the sewage to be treated in the aeration tank section 5 and are purified to a desired degree within a predetermined time. It adjusts to the amount of spout that can advance. At this time, the circulating flow of the sewage to be treated is further promoted by extracting a part of the sewage to be treated from the upper part in the aeration tank part 5 and ejecting the part from the lower inlet 56. In particular, by mounting the inlet 56 near the bottom of the tank, the amount of sewage to be treated stagnating in the lower part of the tank is reduced, and the apparent treatment capacity of the aeration tank unit 5 is increased. The opening toward the bottom of the tank portion 5 allows the lump to be mixed with the circulating flow without accumulating on the bottom, thereby further increasing the processing capacity. If the injection port 56 is made to be an ejection nozzle so that the sewage to be treated in the tank can be stirred, the ejection of bubbles from the bubble generation nozzle 54 is stopped, and the sewage to be treated is ejected from the injection port 56. By causing a circulating flow of the sewage to be treated in the tank, anaerobic treatment by anaerobic microorganisms can also be performed. In addition, by adding the inorganic powder particles to the aeration tank 5, the microorganisms easily adhere to the agglomerates and become lumps, sedimentation is accelerated, and purification is promoted.
An example of this inorganic powder is as follows: 42.4 parts of sewage treated dewatered sludge (water content 37%) 42.4 parts of glass cullet (0.3 mmφ or less) 15.2 parts of construction sludge (water content 41%) at 150 ° C After drying for 2 hours, it is baked at 850 ° C. for 20 minutes and pulverized to about 0.1 to 0.3 mm, and it is preferable to add about 10%.

The bubbles in the sewage to be treated in the aeration tank section 5 gradually increase while circulating in the tank, separate from the sewage to be treated and float up, pass through the air exhaust pipe 35 and the flow pipe 31,
After passing through the inside of the covering tube 32, the sewage to be treated in the settling tank portion 4 is diffused outside the machine without causing turbulence. On the other hand, the aeration tank 5
In the treated sewage that has been purified in the inside, only an amount corresponding to the amount of the treated sewage newly injected into the aeration tank 5 enters the sedimentation tank 4 through the flow pipe 31, and the lower end of the covering pipe 32. It then flows out along the partition 3 and enters the bottom of the settling tank 4.
Then, in the sedimentation tank section 4, the minute flocs that have entered together with the sewage to be treated gradually grow and eventually settle. This floc is scraped outward by the scraping plate 34 by the gentle rotation of the partitioning board 3 (the bottom surface of the sedimentation tank 4), and is formed between the outer peripheral edge and the inner wall surface of the processing tank 2. It falls into the aeration tank part 5 through the gap formed. The floc is stirred together with the other flocs in the aeration tank part 5 to grow further, and finally settles out, is taken out as excess sludge from the drawing pipe 7 attached to the lower end of the processing tank 2, and is discarded. .

[0009]

As described above in detail, according to the present invention, a partition plate is provided in a vertically long processing tank, thereby dividing the processing tank into upper and lower parts to form an aeration tank part and a sedimentation tank part. The partitioning plate has the function of the ceiling surface of the aeration tank part and the bottom surface of the sedimentation tank part, and the treated wastewater aerated in the aeration tank part is directly transferred to the sedimentation tank part through the partitioning plate. As a result, the apparatus can be made compact and continuous processing can be performed, so that the processing capacity has been significantly improved. In addition, flocs that settle in the settling tank return to the aeration tank and grow until they settle here, eliminating the need for a reaction tank or coagulation tank. In addition to improving the capacity, high-concentration wastewater to be treated can be treated. In particular, in the present invention, since the partitioning plate is formed so as to be able to move up and down so that the volume ratio between the aeration tank section and the settling tank section can be adjusted, the concentration of the wastewater to be treated is low and the time required for aeration is short. If the processing capacity per unit volume in the aeration tank unit is large, the volume of the aeration tank unit is reduced by lowering the position of the partition, and the unit time of new wastewater to be treated is reduced. By increasing the per-injection volume, the residence time of the sewage to be treated in the aeration tank can be shortened, and the capacity of the settling tank can be increased to increase the treatment capacity. When the concentration of the sewage is high and the time required for aeration is long, the volume of the aeration tank is increased, conversely, and the treatment time is increased by increasing the residence time of the sewage to be treated in the aeration tank. The best for each sewage to be treated It is is able to work in the processing capacity conditions.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a fluidized bed type sewage treatment apparatus according to the present invention.

FIG. 2 is a schematic view showing an example of sewage treatment by a biological treatment method.

[Explanation of symbols]

 2 Processing tank 3 Partitioning machine 4 Precipitation tank section 5 Aeration tank section 6 Discharge pipe 7 Extraction pipe 8 Machine frame 9 Lifting frame 21 V notch plate 31 Distribution pipe 32 Cover pipe 33 Motor 34 Scrapping plate 35 Air exhaust pipe 51 Inner cylinder 52 Raw water supply pipe 53 Separation plate 54 Bubble generating nozzle 55 Outlet 56 Inlet

Continued on the front page (72) Inventor Kazuhiro Ota 2199 Aikawa, Oigawa-cho, Shita-gun, Shizuoka Prefecture (72) Inventor Kazuhiro Matsushita 2-8-2 Higashishinda, Shizuoka City, Shizuoka Prefecture (72) Inventor Rieko Hotta Aoba, Fujieda City, Shizuoka Prefecture 4-3-17 Machi (72) Inventor Hirofumi Tsutsumi 30-6 Yokosunahigashi-cho, Shimizu-shi, Shizuoka

Claims (2)

[Claims] 1. A partition plate is provided in a vertically long processing tank,
Thereby, the processing tank is divided into upper and lower parts to form an aeration tank part and a sedimentation tank part, and a flow pipe connecting the aeration tank part and the sedimentation tank part is attached to the partition board. A gap is formed between the inner wall surface and the treated wastewater that has been aerated in the aeration tank part, passes directly through the partitioning plate to the sedimentation tank part, and the flocs that have grown and settled in the sedimentation tank part are formed in the aeration tank part. A fluidized bed type sewage treatment apparatus characterized in that it is configured to return. 2. The fluidized bed type sewage treatment apparatus according to claim 1, wherein the partitioning plate is formed so as to be movable up and down.