JPH07204682A - Anaerobic water treatment apparatus - Google Patents

Abstract

PURPOSE:To separate fermentation gas from anaerobic microorganisms by removing effectively scum in a gas-liquid-solid separator. CONSTITUTION:A reaction vessel 2 is installed which treats waste water with pelletized methane bacteria 4 while fermentation gas being generated; gas-liquid- solid separators 10a, 10b are installed in the upper part of a reaction vessel 2. The separator 10a, 10b is divided into a gas phase part 21 and a liquid phase part 22 by a water surface positioned below the surface of treated water in the reaction vessel 2. The one end of scum extraction pipe 11a, 11b is opened in the gas phase part 21 and below the surface of treated water in the reaction vessel 2; the other end of the 11a, 11b is connected with the scum tank 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anaerobic water treatment device for purifying organic wastewater such as industrial wastewater by the action of anaerobic microorganisms.

[0002]

2. Description of the Related Art An anaerobic water treatment method using anaerobic microorganisms such as methane-fermenting bacteria has less excess sludge than an activated sludge method using aerobic bacteria and does not require power for aeration. . Moreover, since methane is generated, energy can be recovered. However, on the other hand, the decomposition rate of organic substances is slow and the processing time is long.

In order to solve such a problem, an anaerobic methane-fermenting bacterium has been self-granulated (granule) as a methane-fermentation treating apparatus in which the concentration of the methane-fermenting bacterium is increased and the treatment time is shortened. A sludge bed type (UASB type) water treatment device has been proposed and is being put to practical use mainly for high-concentration wastewater such as industrial wastewater.

FIG. 4 is a block diagram of a conventional UASB type methane fermentation treatment apparatus. In FIG. 4, the waste water is introduced from the lower part of the reaction tank 2 by the raw water pump 1. The methane bacterium granules 4 are flowing in the reaction part 3 in the reaction tank 2. While the wastewater flows upward in the reaction section 3, organic substances in the wastewater are decomposed, and biogas containing methane and carbon dioxide as main components is generated.

The biogas rises in the reaction section 3 and the refining section 5 formed in the upper part of the reaction section 3, and gas-solid separation devices 10a, 10
b, introduced into the water trap tank 7 via the gas pipeline 6.
The water trap tank 7 is sealed with water, and the gas-solid separation device 10
The water level in a and 10b is adjusted. After exiting from the water trap tank 7, the biogas is temporarily stored in the gas holder 8 and is effectively used as fuel for a gas boiler or the like.

The purified treated water overflows from the upper part of the reaction tank 2 and is drawn out of the system through the treated water pipe 9.

[0007]

In the above-mentioned UASB type methane fermentation treatment apparatus, when treating wastewater containing a large amount of lipids and proteins, a gas-solid separation apparatus 10 is used.
Foaming and scum may occur in a and 10b. In this case, the biogas adhering to the granules of methane bacteria is not well removed in the gas-solid separation devices 10a and 10b,
Therefore, the methane bacterium granules 4 accumulate in the gas-solid separation devices 10a and 10b and gradually flow out into the treated water.
In this way, when the methane bacteria granulated product 4 flows out into the treated water,
Since a sufficient amount of cells cannot be retained in the reaction section 3, the treatment efficiency becomes poor. Further, if the separation of the methane bacterium granules and the biogas in the gas-solid separation devices 10a and 10b is not performed well, there is also a problem that the formation of the methane bacterium granules 4 fails.

The present invention has been made in consideration of the above points, and scum and methane bacterium granules are not accumulated in the gas-solid separation device, and biogas is satisfactorily obtained from methane bacterium granules. An object is to provide an anaerobic water treatment device that can be released.

[0009]

The invention according to claim 1 is
Using an anaerobic microorganism, a reaction tank that treats organic wastewater while producing fermentation gas to produce treated water, and a water surface located below the treated water surface of the reaction tank, A gas-solid separation device which is divided into a gas phase part and a liquid phase part and separates a fermentation gas and anaerobic microorganisms, and a gas phase part of the gas-solid separation device, which is below the treated water surface of the reaction tank. An anaerobic water treatment apparatus comprising: a scum extraction pipe having one end opened and a valve attached thereto; and a scum tank connected to the other end of the scum extraction pipe.

According to the second aspect of the present invention, a reaction tank for treating organic wastewater by using anaerobic microorganisms while producing fermentation gas into treated water, and a reaction tank installed above the reaction tank, The interior is divided into a gas phase part and a liquid phase part by the water surface located below the treated water surface, and a gas-solid separation device for separating fermentation gas and anaerobic microorganisms, and a gas-phase part of this gas-liquid separation device. And a circulation pipe having one end connected to the gas pipe, the other end opening in the liquid phase of the gas-liquid separator, and a blower attached. It is a characteristic anaerobic water treatment device.

According to the third aspect of the present invention, a reaction tank for treating organic wastewater by using anaerobic microorganisms while producing fermentation gas into treated water, and a reaction tank installed above the reaction tank, The interior is divided into a gas phase part and a liquid phase part by the water surface located below the treated water surface, and a gas-solid separation device for separating fermentation gas and anaerobic microorganisms, and a gas-phase part of this gas-liquid separation device. An anaerobic water treatment device, comprising: a shower pipe that is opened at the end to inject water onto the water surface.

[0012]

According to the first aspect of the present invention, when the valve of the scum extraction pipe is opened, the fermentation gas in the gas phase part of the gas-liquid separation device is discharged from the scum extraction pipe. The water surface in the gas-solid separation device rises, and scum on the water surface in the gas-liquid separation device is drawn from the scum extraction pipe to the scum tank.

According to the second aspect of the present invention, the fermentation gas in the gas-liquid separation device is partially branched by the circulation pipe, pressurized by the blower, and blown into the liquid phase portion of the gas-liquid separation device. The blowing of the fermentation gas destroys the scum on the water surface in the gas-solid separation device.

According to the third aspect of the present invention, since the water is jetted to the water surface from the shower pipe opening in the gas phase portion of the gas-solid liquid separating apparatus, the scum on the water surface in the gas-solid separating apparatus is destroyed. To be done.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of an anaerobic water treatment system according to the present invention.

In FIG. 1, the anaerobic water treatment apparatus is provided with a reaction tank 2 into which organic wastewater flows in via a raw water pump 1, and the reaction tank 2 uses a microorganism of a methane bacterium granulated product 4 such as biogas. Is divided into a reaction section 3 for treating the organic wastewater while producing the fermentation gas and a refining section 5 located above the reaction section 3. At the upper part of the reaction tank 2, gas-solid separation devices 10a and 10b for separating the biogas adhering to the methane bacteria granulated product 4 from the methane bacteria granulated product 4 are installed.
The interiors of the gas-solid separation devices 10a and 10b are divided into a gas phase portion 21 and a liquid phase portion 22, of which one end of the gas pipeline 6 is connected to the gas phase portion 21 and the other of the gas pipeline 6 is connected. The end is connected to the water trap tank 7. The other end of the gas pipeline 6 is water-sealed in the water trap tank 7, and the gas-solid separation device 1 is caused by the water head difference between the water surface in the water trap tank 7 and the tip of the gas pipeline 6.
The water surfaces in 0a and 10b are maintained below the water surface of the fining unit 5.

A gas holder 8 for temporarily storing biogas is connected to the water trap tank 7, and the treated water in the refining section 5 flows out from the treated water pipeline 9.

Further, as shown in FIG. 1, a gas-solid separation device 1
The scum extraction pipe 11 is located below the treated water surface of the reaction tank 2 (water surface of the refining portion 5) in the vapor phase portion 21 of 0a and 10b.
One end of a and 11b is opened, and scum extraction pipes 11a and 11b
The other end of b is connected to the scum tank 12. Further, valves 18a and 18b are attached to the scum extraction pipes 11a and 11b.

Next, the operation of this embodiment having such a configuration will be described. As shown in FIG. 1, the wastewater flows into the lower part of the reaction tank 2 by the raw water pump 1 and flows to the upper part of the reaction tank 2 in an upward flow. The methane bacterium granules 4 are flowing in the reaction part 3 in the reaction tank 2, and the methane bacterium granules 4 generate biogas mainly composed of methane and carbon dioxide gas, while organic matters in the wastewater are removed. It is decomposed and wastewater is purified. The purified treated water is discharged to the outside from the upper part of the refining section 5 through the treated water pipe 9. Further, a part of the biogas generated in the reaction section 3 adheres to the methane bacterium granules 4 and raises the methane bacterium granules 4. The biogas adhering to the methane bacterium granules 4 is separated from the methane bacterium granules 4 by the gas-solid separation devices 10a and 10b, and the methane bacterium granules 4 settle into the reaction section 3. On the other hand, biogas is a gas-solid separation device 1
The gas phase portions 21 of 0a and 10b flow into the water trap tank 7 through the gas pipeline 6. Next, the biogas is temporarily stored in the gas holder 8 and is effectively used for a gas boiler or the like.

When the wastewater contains a large amount of lipids and proteins, bubbles and scum are generated in the gas-solid separation devices 10a and 10b.
Accumulate inside. In this case, the biogas is less likely to separate from the methane bacterium granules 4, and the methane bacterium granules 4 accumulate in the gas-liquid separation devices 10a and 10b. For this reason, the scum extraction pipes 11a, 1a, 1
The valves 18a and 18b installed in 1b are opened, and the scum is regularly withdrawn into the scum tank 12.

That is, when the valves 18a, 18b are opened, the biogas in the gas-solid separation devices 10a, 10b escapes from the scum extraction pipes 18a, 18b, and the gas-liquid separation device 1
The pressure in 0a and 10b decreases. In this case, the water level in the gas-solid liquid separation devices 10a, 10b rises to the treated water surface of the reaction tank 2, and the scum in the gas-liquid liquid separation devices 10a, 10b is extracted together with the liquid in the refining section 5 by the action of the siphon. . The biogas that first comes out of the gas-solid separation devices 10a and 10b contains a large amount of methane and has a bad odor, so it is desirable to put it in the gas holder 8 through a pipe (not shown). Further, the frequency of extracting the scum varies depending on the composition of the wastewater, the concentration of organic substances, the operation method, and the like. Although it is necessary to make an empirical decision while actually driving, the frequency may be about once a week.

In this way, the gas-solid separation device 10a,
The scum can be removed from 10b, whereby the biogas can be reliably separated from the methane bacterium granules 4 and the methane bacterium granules 4 can be prevented from accumulating in the gas-solid separation device. Therefore, the methane bacterium granules 4 do not flow out into the treated water, and the amount of the microbial cells in the reaction section 3 can be sufficiently secured to efficiently perform the wastewater treatment.

Next, a second embodiment of the anaerobic water treatment apparatus according to the present invention will be described with reference to FIG.

In FIG. 2, the same parts as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted.

In the second embodiment shown in FIG. 2, one end of the circulation pipe 14 is connected in the middle of the gas pipe 6, and the other end of the circulation pipe 14 is connected to the liquid phase portion 22 of the gas-solid separation devices 10a and 10b. The second embodiment is substantially the same as the first embodiment except for the above. A blower 13 for increasing pressure is attached to the circulation pipe 14.

In FIG. 2, wastewater flows from the raw water pump 1 into the lower part of the reaction tank 2 and flows upward into the upper part of the reaction tank 2. Granules 4 of methane bacteria in the reaction part 3 in the lower part of the reaction tank 2
Are flowing, and the organic matter in the wastewater is decomposed by the methane bacterium granules 4 to purify the wastewater. The purified treated water is discharged from the refining section 5 in the upper part of the reaction tank 2. In addition, the biogas generated in the reaction section 3 is a gas-solid separation device
The water flows into the water trap tank 7 through a, 10b and the gas pipe 6. Next, the biogas is temporarily stored in the gas holder 8 and is effectively used.

A part of the biogas in the gas pipe 6 is branched into the circulation pipe 14, the pressure is increased by the blower 13, and the biogas is blown into the liquid phase portion 22 of the gas-solid separation devices 10a and 10b.
Stir the water surface. By such a stirring action, scum generated in the gas-solid separation devices 10a and 10b can be destroyed. Therefore, the biogas can be efficiently separated from the methane bacteria granulated product 4 without impairing the functions of the gas-solid separation devices 10a and 10b. Since the appropriate amount of biogas blown into the gas-solid separation devices 10a and 10b varies depending on the composition of wastewater, the concentration of organic matter, etc.,
It is desirable to decide in advance by a preliminary test.

Next, referring to FIG. 3, a third embodiment of the anaerobic water treatment system according to the present invention will be described. In FIG. 3, the same parts as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The third embodiment shown in FIG. 3 is a treated water pipeline 9
Connect one end of the shower tube 16 in the middle of the
The injection ports 16a and 16b are provided at the other end of
6a and 16b are arranged in the gas phase portion 21 of the gas-solid separation devices 10a and 10b, and the other points are substantially the same as in the first embodiment. The booster pump 15 is attached to the shower tube 16.

In FIG. 3, the waste water flows into the lower part of the reaction tank 2 by the raw water pump 1 and flows upward in the reaction tank 2. The methane bacterium granules 4 are flowing in the reaction section 3 in the lower part of the reaction tank 2, and the methane bacterium granules 4 decompose organic matters in the waste water to purify the waste water. The purified treated water is discharged from the refining section 5 in the upper part of the reaction tank 2. Further, the biogas generated in the reaction part 3 passes through the gas-solid separation devices 10a and 10b and the gas pipe 6, and then the water trap tank 7
Flow into. Next, the biogas is temporarily stored in the gas holder 8 and is effectively used.

The treated water in the treated water pipe 9 is branched, and a part of the treated water is sent to the gas phase section 21 of the gas-solid separation devices 10a and 10b by the pressure boosting pump 15 via the shower pipe 16 and jetted from the shower pipe 16. Gas-solid separation device 1 from ports 16a and 16b
It is injected to the water surface in 0a and 10b. By injecting the treated water in this way, the gas-solid separation devices 10a, 10b
Even if scum is generated inside, it can be surely destroyed. Therefore, the biogas can be efficiently separated from the methane bacteria granulated product 4 without impairing the functions of the gas-solid separation devices 10a and 10b. The amount of the treated water sprayed from the shower tube 16 varies depending on the composition of the waste water, the concentration of organic substances, and the like, so it is desirable to determine it in advance by a preliminary test.

When it is difficult to use the treated water due to a water quality problem or the like, instead of circulating the treated water, fresh water such as tap water is sprayed into the gas-solid separation devices 10a and 10b. Good.

In each of the embodiments shown in FIGS. 1 to 3, the scum extraction pipes 11a and 11b (first embodiment), the circulation pipe 14 having the blower 13 (second embodiment), and the shower pipe 16 are provided. Although an example in which (third embodiment) is separately provided is shown, the present invention is not limited to this, and the scum extraction pipes 11a, 11 are not limited thereto.
b, circulation pipe 14 having a blower, and shower pipe 1
6 can be simultaneously provided in the same anaerobic water treatment device.

[0034]

As described above, according to the present invention,
Since the scum can be removed from the gas-solid separation device, it is possible to separate the fermentation gas from the anaerobic microorganisms and prevent the anaerobic microorganisms from accumulating in the gas-liquid separation device. Therefore, the amount of anaerobic microorganisms in the reaction tank can be sufficiently secured without the anaerobic microorganisms flowing out into the treated water.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of an anaerobic water treatment device according to the present invention.

FIG. 2 is a schematic view showing a second embodiment of the anaerobic water treatment device according to the present invention.

FIG. 3 is a schematic view showing a third embodiment of the anaerobic water treatment device according to the present invention.

FIG. 4 is a schematic view showing a conventional anaerobic water treatment device.

[Explanation of symbols]

 2 Reaction tank 4 Methanobacterial granules 6 Gas pipeline 7 Water trap tank 8 Gas holder 9 Treated water pipeline 10a, 10b Gas-solid separation device 11a, 11b Scum extraction tube 12 Scum tank 13 Blower 14 Circulation piping 15 Booster pump 16 Shower pipe 18a, 18b valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ms. Kaoru 1Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation

Claims (3)

[Claims] 1. A reaction tank for treating organic wastewater by using anaerobic microorganisms while producing fermentation gas into treated water, and a reaction tank installed above the reaction tank and located below the treated water surface of the reaction tank. The inside of the gas-liquid separation device is divided into a gas-phase part and a liquid-phase part by the water surface and separates the fermentation gas from the anaerobic microorganisms. The anaerobic water treatment device having one end open below the treated water surface of the above, and a scum extraction pipe to which a valve is attached, and a scum tank connected to the other end of this scum extraction pipe. . 2. A reaction tank for treating organic wastewater by using anaerobic microorganisms while producing fermentation gas to obtain treated water, and a reaction tank installed above the reaction tank and located below the treated water surface of the reaction tank. The inside of the gas-liquid part is divided into a gas phase part and a liquid phase part by the water surface, and a gas-solid separation device for separating fermentation gas and anaerobic microorganisms, and a gas pipe connected to the gas-phase part of this gas-solid separation device And a circulation pipe having one end connected to the gas pipeline, the other end opening into the liquid phase of the gas-solid separation device, and a blower attached. Processing equipment. 3. A reaction tank for treating organic wastewater by using anaerobic microorganisms while producing fermentation gas into treated water, and a reaction tank installed above the reaction tank and located below the treated water surface of the reaction tank. The inside is divided into a gas phase part and a liquid phase part by the water surface to be separated, and a gas-solid separation device for separating the fermentation gas and the anaerobic microorganisms, and the gas-phase part of this gas-liquid separation device is opened to the water surface. An anaerobic water treatment device comprising: a shower tube for injecting water.