JPH08103793A - Anaerobic treatment device - Google Patents

Abstract

PURPOSE: To provide an anaerobic treatment device which can transfer in an anaerobic reactor, suspended sludge having been lifted up without using power by utilizing gas generated in the reactor so that the sludge can be crushed to restore its precipitating property, thereby to effect anaerobic treatment efficiently. CONSTITUTION: A reaction zone 11 is formed, in an anaerobic treatment reactor 1 of UASB system, to have a solid-liquid separation section 9 inside the upper section of the reactor, a gas collecting section 10 outside the upper section, and a sludge blanket 13 in the lower section, the sections being separated by solid-liquid separation members 8a, 8b, whereby the suspended sludge having been lifted up to the section 9 and/or the section 10 is taken out and sent into a suspended sludge takeout section 14, which sludge is then transferred to a crushing device 27 by a gas lift 16 utilizing gas captured by a gas trap 21, so that the suspended sludge is crushed to restore its precipitating property and returned to the reactor 1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention uses organic waste liquid UASB.
The present invention relates to an anaerobic treatment device for anaerobic treatment by the (upstream sludge blanket) method.

[0002]

2. Description of the Related Art As a method of anaerobic treatment of organic waste liquid, a granular sludge having a high density and a large sedimentation property is formed, and an organic waste liquid containing soluble BOD is upwardly flowed to form a sludge blanket. The UASB method is employed in which the high-load and high-speed processing is performed by bringing them into contact with each other in the formed state. In this method, solid organic matter with a slow digestion rate is separated and treated separately, and only soluble organic matter with a fast digestion rate is treated at high speed with high load by anaerobic treatment using granulated sludge with high anaerobic microorganism density. It is a method and is distinguished from the traditional anaerobic treatment.

The conventional anaerobic digestion method is a method in which an organic waste liquid containing a solid organic matter and a soluble organic matter is directly introduced into a digestion tank for anaerobic digestion, which is a long process in the step of solubilizing the solid organic matter. Since it takes time, 20-4 as a whole
A long residence time of 0 days is required, and a large processing device is required. On the other hand, since the UASB method uses granule-like sludge in which highly active anaerobic microorganisms are accumulated and has a large settling property, solid-liquid separation is improved even at high flow rates, and a large amount of sludge is retained in the tank. However, the sludge concentration in the tank can be maintained high, and thus the anaerobic treatment can be performed with high treatment efficiency, and the treatment can be efficiently performed using a small apparatus.

[0004] In the anaerobic digestion method, sludge is fine and light, so that the produced gas floats when it adheres to form scum on the liquid surface, but when the scum is crushed by stirring and the sludge and gas are separated, Sludge settles and scum formation is prevented. On the other hand, in the UASB method, since the sludge that is granulated and has a good sedimentation property is used, the sludge usually does not float up with the digested gas to form scum unlike the anaerobic digestion method, and therefore scum is not generated. It is said that there is no need to perform the operation of crushing and returning to the reaction section, and the operation operation is simple.

However, among the UASB type anaerobic treatment apparatuses, a BOD load of 10 kg / m ³ ·
In a device that performs high-load treatment of d or more, a phenomenon in which the granular sludge floats up to form scum, the floating sludge flows out into the treated water, and the sludge holding amount in the anaerobic reaction tank decreases is observed. . When this sludge floats or flows out, the treatment becomes insufficient, making it difficult to perform high-load operation, which is a characteristic of the UASB system, and anaerobic sludge flows into the activated sludge treatment device that is the post-treatment of the UASB system. The DO of the aeration tank is significantly reduced, and the treatment performance of the activated sludge treatment device is reduced. The above-mentioned sludge flotation is similar in phenomenon to that of scum in the conventional anaerobic digestion method, but unlike flocculation that accompanies the adhering gas like scum, unlike the case of the granulated sludge itself. This is because the specific gravity is small, and just by removing the gas adhering to the outside like a conventional scum breaker, the sedimentation property cannot be recovered.

Most of the granular sludge floating in the UASB type anaerobic reaction tank has a small specific gravity because the gas generated by the anaerobic reaction is contained inside the granular sludge. There are many cases where Therefore, by crushing the granular sludge enclosing the gas, it is possible to release the gas in the encapsulated state and form a blanket, which is the original existing form of the granular sludge. Therefore, in a UASB-type anaerobic treatment device, the granular sludge floating in the reaction tank is appropriately discharged to the outside of the reaction tank, and the discharged sludge is crushed using a crushable pump, mixer, homogenizer, etc. Attempts have been made to return the film to the reaction tank in an exposed state (for example, JP-A-6-182382).

[0007]

However, the recent anaerobic treatment device has a completely closed structure from the viewpoint of odor control, and it is difficult to efficiently collect the sludge floating in the reaction tank. In many cases, the floating granulated sludge is left in the reaction tank for a long period of time. Therefore, the floating sludge flows out together with the treatment liquid, and the retained amount of the granulated sludge forming a good blanket in the reaction tank gradually decreases, which makes normal anaerobic treatment difficult. Even when a sludge collecting device such as a gas injection nozzle on the liquid surface of the solid-liquid separation unit is provided as in the above publication, it is difficult to efficiently take out the floating sludge because the operating condition cannot be confirmed in the reaction tank having a closed structure. There is a problem that is.

The object of the present invention is to solve the above-mentioned problems in the UASB method, and even when the granular sludge floats up, the sludge is efficiently taken out and the sedimentation property is recovered and returned to the reaction section. An object of the present invention is to provide an anaerobic treatment device capable of maintaining high sludge concentration in a tank and performing treatment with high treatment efficiency.

[0009]

DISCLOSURE OF THE INVENTION The present invention has an anaerobic reaction tank having a reaction section in which a sludge blanket made of granulated sludge containing anaerobic microorganisms is formed, and having a treated liquid inflow section at the bottom. And a solid-gas separation member disposed on the upper part of the reaction part so as to be inclined so as to separate the solid-liquid separation part and the gas collection part, and a communication passage for connecting the lower part of the solid-liquid separation part and the reaction part. The treated liquid extraction part provided near the liquid surface of the solid-liquid separation part, the floating sludge extraction part provided in the solid-liquid separation part and / or the gas collection part, and the floating sludge extracted from the floating sludge extraction part are crushed. And a crushing device that returns it to the reaction section,
An anaerobic treatment device comprising: a gas lift that transfers the floating sludge from the floating sludge extraction unit to the shredding device by using the gas collected in the gas collecting unit.

Although the growth process of the granulated sludge in the UASB method is not clear, anaerobic microorganisms are present on the surface of fine inorganic SS having a particle diameter of about 0.1 mm and the surface of scale components containing calcium and magnesium. When attached, new anaerobic microorganisms grow and attach in an annual ring shape with the minute SS and scale as the nucleus, and when it takes several months or more to grow into granular sludge with a particle size of 0.5 to 1 mm. Has been done. It is said that the grown granular sludge is crushed by the flow of water and gas generated in the reaction tank, and the crushed fine particles and fragments serve as nuclei to grow the next granular sludge.

When the grown granular sludge is not crushed, or when the crushed ratio or degree is small, as the sludge continues to grow and the particle size becomes 1 mm or more, the inside of the granular sludge becomes larger. Anaerobic microorganisms and organic SS components self-decompose. Then, after self-decomposition, it becomes hollow, and the gas generated by the methanogenic reaction is accumulated in the hollow, and the specific gravity of the granulated sludge is reduced by the enclosed gas, and as a result, the granular sludge floats up and flows out. Conceivable.

When the load amount in the UASB method is low,
The growth of granulated sludge and the rate of crushing of the grown sludge are balanced, so the proportion of granulated sludge that grows to a large particle size and contains gas is small, and the sludge floats, The outflow phenomenon is not remarkable. On the other hand, when the treatment is performed at a high BOD load of 10 to 15 kg / m ³ · d, the growth rate of the granulated sludge is
The rate is much higher than the rate of shredding, and sludge floating and runoff phenomena increase. Therefore, when the UASB system operates under high load, scale components with a high specific gravity and inorganic SS
Unless sludge is constantly supplied, the floating phenomenon of granulated sludge occurs.

Therefore, in the present invention, the floating sludge is efficiently taken out and appropriately crushed to reduce the average particle size of the floating sludge, and at the same time, the cavitation inside is exposed to the outer surface to recover the sedimentation property. However, it is configured to maintain a high sludge concentration in the tank. The anaerobic reaction tank in the UASB method is
Although it has a closed structure as a measure against odorous gases such as organic acids and sulfur compounds that are generated, in order to efficiently remove the floating sludge from the anaerobic reaction tank having such a closed structure, the present invention uses a gas lift that utilizes the generated gas. Is used to transfer the floating sludge to the crusher.

The gas lift is provided so as to communicate with the crushing device from the floating sludge take-out section, and the gas collected in the gas collecting section is introduced therein to transfer the floating sludge. It is preferable that the floating sludge take-out part is opened at a position lower than the treatment liquid take-out part. As the crushing device, a pump having a crushing mechanism such as a grinder pump, a mixer or a homogenizer can be used. Such a crushing device is generally provided outside the anaerobic reaction tank, but may be provided inside the anaerobic reaction tank.

[0015]

In the method for anaerobic treatment using the anaerobic treatment apparatus of the present invention, first, the granulated sludge containing anaerobic microorganisms granulated by utilizing the self-granulating property of the anaerobic microorganisms is stored in the anaerobic reaction tank. It is charged into the reaction part, and the organic drainage is introduced from the treated liquid inflow part provided in the bottom part, and is passed in the upward flow to form a sludge blanket, which is contacted under anaerobic conditions. As a result, the soluble organic matter in the effluent is decomposed into methane and carbon dioxide by the action of the anaerobic microorganisms through the acid producing step and the methane producing step.

Since the granular sludge has a high density and an excellent settling property, a uniform sludge blanket is formed by passing the waste liquid in an upward flow and retained in the reaction section. The waste liquid that has passed through the sludge blanket enters the solid-liquid separation portion from the communication passage, is separated into the solid-liquid portion there, and the separated liquid is taken out as the processing liquid from the processing liquid take-out portion. The separated sludge settles and returns from the communication passage to the reaction section. Gas such as methane generated in the reaction section rises in the reaction section, but is blocked by the solid-gas separation member and does not flow into the solid-liquid separation section, but is taken out from the gas collection section.

In a normal operating condition when the load is relatively low, the granulated sludge does not float up, and the sludge that has flowed into the solid-liquid separation section settles as it is and returns to the reaction section, but when operating under a high load Alternatively, when the operation is continued for a long period of time, the apparent specific gravity of the granulated sludge becomes small and floats, and then floats on the liquid surface of the gas collection part or the solid-liquid separation part. Therefore, in the present invention, the floating sludge that has floated in the solid-liquid separation section and / or the gas collection section is taken out from the floating sludge take-out section and transferred to a crusher by a gas lift to be crushed. When the floating sludge in the solid-liquid separation unit is transferred, the gas floating in the gas collection unit is captured by the gas trap and introduced into the gas lift, and the floating sludge is transferred. The gas is compressed in the gas trap, so if you release it intermittently,
Since a large amount of gas is released at one time, the floating sludge can be efficiently transferred with a small amount of gas.

In the present invention, the anaerobic reaction is carried out while the floating sludge thus taken out is crushed by the crushing device and returned to the reaction section. Since the floating sludge has a hollow portion formed inside, when the hollow sludge is crushed so that the hollow portion is exposed on the surface, the granulated sludge returns to its original state of high specific gravity and the sedimentation property is restored. The degree of crushing at this time is such that most of the crushed sludge has a particle size of 0.2 to 1 mm, preferably 0.3.
Appropriately it is about 0.7 mm. If the particle size of the crushed sludge is less than 0.2 mm, it tends to flow out together with the treatment liquid, and if it exceeds 1 mm, it is not preferable because the hollow portion is not exposed and the sedimentation property is not recovered in many cases.

In the case of crushing with a pump having a sludge crushing mechanism, the crushing degree is confirmed in advance by using a special pump having a vortex system or a foreign matter crushing mechanism, and the rotation speed and the suitable crushing condition are adjusted. It is preferable to operate at the flow rate. The proper crushing condition can be checked and adjusted by measuring the particle size of crushed sludge. Even when a mixer, a homogenizer or the like is used for crushing, it is preferable to adjust the stirring strength while checking the crushing condition.

If the treatment is continued without crushing the floating sludge as described above, the floating sludge flows out together with the treated water, and the sludge amount decreases and the treatment efficiency decreases, but the sludge is crushed to the reaction section. By returning, sludge concentration in tank (amount of sludge in tank /
The reaction volume) remains high. Sludge concentration in the tank is 100
It can be maintained at 00 mg / l or more. The organic waste liquid to be treated in the present invention is a waste liquid containing a soluble organic substance, and may contain some solid organic substance. When a large amount of solid organic matter is contained, the solid organic matter removed in advance by solid-liquid separation is subjected to treatment.

Although the present invention is applied to a high load anaerobic treatment apparatus by the UASB method, it does not depend on the operating temperature of the UASB apparatus, and the treatable temperature is from 20 ° C to 45 ° C.
The present invention can be applied to either the intermediate temperature treatment which is between 0 ° C or the high temperature treatment which has a temperature range capable of being treated at 45 ° C or higher. The upward flow velocity of the drainage in the anaerobic treatment tank is 0.5 to
2 m / hr, preferably 1 to 1.5 m / hr, and a residence time of 4 to 48 hours, preferably 6 to 24 hours are suitable.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments of the drawings. FIG. 1 is a sectional view of a UASB type anaerobic treatment apparatus according to an embodiment. In the figure, 1 is an anaerobic reaction tank,
It is composed of a rectangular parallelepiped container, and the liquid to be treated inflow portion 2 is uniformly provided at the bottom thereof and communicates with the liquid to be treated introducing passage 3. An upper part of the anaerobic reaction tank 1 is covered with a cover 4 to form a gas chamber 5 having a closed structure, and a gas extraction path 6 is connected to the top of the gas chamber 5.

A liquid chamber 7 is formed below the gas chamber 5 in the anaerobic reaction tank 1, and a solid gas composed of first and second partition plates inclined in opposite directions is formed above the liquid chamber 7. Separation members 8a, 8
b is arranged, and a solid-liquid separating section 9 is partitioned inside the upper part, a gas collecting section 10 is partitioned outside the upper part, and a reaction section 11 is partitioned below. The lower ends of the solid-gas separating members 8a and 8b are isolated from each other to form a communication passage 12, and one lower end covers the lower side of the other lower end so that the floating gas flows from the communicating passage 12 to the solid-liquid separation unit 9. It has a structure that prevents entry.

The organic waste liquid is introduced into the liquid chamber 7 in the anaerobic reaction tank 1, and the sludge blanket 13 is formed in the reaction section 11. An overflow type floating sludge take-out unit 14 is provided in the liquid surface portion of the upper part of the solid-liquid separation unit 9 immediately above the communication passage 12, and is connected to the floating sludge take-out passage 17 via a downcomer pipe 15 and a gas lift 16. There is.
Further, an overflow type processing liquid take-out portion 18 is provided on the solid-gas separation members 8a, 8b side away from the vicinity of the direct upper part of the communication passage 12 above the solid-liquid separation portion 9 and communicates with the processing liquid take-out path 19. are doing. The floating sludge take-out part 14 is provided at a position 1 to 5 cm lower than the treatment liquid take-out part 18, and a baffle 20 is provided near the liquid surface between the take-out parts 14 near the treatment liquid take-out part 18. . The gas lift 16 is composed of an ascending pipe, and a gas introduction pipe 22 is connected to a lower portion of the gas lift 16 from a gas trap 21 provided in the gas collection unit 10.

Reference numeral 25 is a floating sludge tank, which has a gas chamber 5a at the top.
A liquid chamber 7a is formed in the lower portion, a pressure equalizing pipe 26 is connected to the gas chamber 5a from the gas chamber 5a of the anaerobic reaction tank 1, and a floating sludge take-out path 17 is connected to the liquid chamber 7a. Liquid chamber 7a
A sludge return passage 28 communicates with the liquid chamber 7 of the anaerobic reaction tank 1 via the crushing pump 27. The crushing pump 27 can adjust the crushing strength, and the particle size of the crushing sludge is 0.3 to 0.
It is adjusted to be 7 mm so that it can be corrected when the particle size of the crushed sludge during operation is out of the above range.

In the anaerobic treatment method using the above anaerobic treatment apparatus, first, a granular sludge containing anaerobic microorganisms granulated by utilizing the self-granulating property of anaerobic microorganisms is used as a reaction part of the anaerobic reaction tank 1. Put in 11. Then, the organic waste liquid is introduced from the liquid to be treated introduction passage 3 into the liquid to be treated 2 provided at the bottom of the anaerobic reaction tank 1, and the sludge blanket 13 is formed by passing the liquid in an upward flow to form an anaerobic gas. The anaerobic reaction is carried out by contacting under sex. As a result, the soluble organic matter in the effluent is decomposed into methane and carbon dioxide by the action of the anaerobic microorganisms through the acid producing step and the methane producing step.

Since the granular sludge has a high density and an excellent settling property, a uniform sludge blanket 13 is formed by passing the waste liquid in an upward flow, and is retained in the reaction section 11. The organic waste liquid that has passed through the sludge blanket 13 enters the solid-liquid separation unit 9 from the communication passage 12, and is separated into solid-liquid there, and the separated liquid overflows from the processing liquid extraction unit 18 and is treated as a processing liquid extraction passage 19 as a processing liquid. Taken out. The separated sludge settles down, and the reaction passage 1 passes through the communication passage 12.
Return to 1. Gas such as methane generated in the reaction section 11 rises in the reaction section 11, but is blocked by the solid-gas separation members 8a and 8b and does not flow into the solid-liquid separation section 9, but is collected in the gas collection section 10. It is taken out from the gas chamber 5 to the gas take-out path 6. A part of the gas rising at this time is captured by the gas trap 21.

Under normal operating conditions with a low load, the granulated sludge does not float on the liquid surface, and the sludge flowing into the solid-liquid separation section 9 settles as it is and returns to the reaction section 11.
When the operation is performed under a high load, or when the operation is continued for a long time, the apparent specific gravity of the granulated sludge becomes small and floats, and floats on the liquid surface of the solid-liquid separation section 9.

In this case, the buoyant sludge that has entered the solid-liquid separation section 9 from the communication passage 12 directly rises as it is, overflows from the levitation sludge extraction portion 14 located immediately above the communication passage 12, and is taken out by the downcomer pipe 15. Down.

At this time, the gas trap 21 of the gas collecting section 10
The gas captured by the gas lift pipe 16 from the gas introduction pipe 22
Then, the sludge in the downcomer pipe 15 is pushed up to the floating sludge take-out path 17 and transferred to the floating sludge tank 25. In the solid-liquid separation unit 9, the floating sludge is blocked by the baffle 20 and does not reach the treatment liquid extraction unit 18, so that it does not flow out to the treatment liquid extraction passage 19. The gas chambers 5 and 5a are kept at a uniform pressure by the pressure equalizing pipe 26, and the floating sludge take-out part 14 is opened at a position lower than the treatment liquid take-out part 18. Therefore, the floating sludge flows into the floating sludge tank 25 at a substantially constant flow rate. Transfer.

The floating sludge introduced into the floating sludge tank 25 is returned to the reaction section 11 through the sludge return passage 28 which is crushed by the crushing pump 27. Since the floating sludge has a hollow portion formed inside, by crushing so that the hollow portion is exposed on the surface, the sludge is restored to its original state of high specific gravity and the sedimentation property is restored. By thus crushing the floating sludge and performing the anaerobic reaction while returning the sludge to the reaction section 11, the sludge concentration in the tank is kept high and the treatment efficiency is kept high.

In the above apparatus, since the floating sludge take-out section 14 is provided in the vicinity of the upper part of the communication passage 12, the communication passage 1
The buoyant sludge that has passed through 2 is directly taken out or is taken out from the buoyant sludge taking-out section 14. Further, since the treatment liquid take-out part 18 is arranged at a position away from the upper part of the communication passage 12 and the baffle 20 is provided in the floating sludge take-out part 14 and the treatment liquid take-out part 18, the floating sludge flows out together with the treatment liquid. Is prevented.

In the gas lift 16, the floating sludge is transferred by using the gas captured by the gas collecting section 10, so that it can be always transferred without power. The diameter of the gas lift 16 is 4 cm, the depth below the liquid surface is 1.5 m, and the height above the liquid surface is 0.
When it is set to 5 m, the required gas amount is 5.2 m ³ / hr, and at this time, the sludge transfer capacity is 8.3 m ³ / hr.
When the load of CODcr is 15 kg / m ³ / day, the amount of gas generated is ^{30 to} 60 m ³ / m ² / m ² / bottom area of the reaction section.
Since it is a day, it is possible to transfer a part of the generated gas to the gas lift.

Since the floating sludge take-out section 14 opens at a position lower than the treatment liquid taking-out section 18, the floating sludge is taken out by a fixed amount, and it is possible to avoid staying in the solid-liquid separation section 9. Further, since the crushing pump 27 crushes the floating sludge that flows in by a fixed amount, the crushing pump 27 can easily crush the floating sludge into a fixed particle size, thereby recovering the sedimentation property of the sludge and performing an efficient anaerobic treatment. it can.

The floatable sludge floating on the gas collecting section 10 is easily circulated to the reaction section 11 by stirring due to the release of gas,
Although it finally flows into the solid-liquid separation section 9 from the communication passage 12 and is taken out from the floating sludge taking-out section 14, the gas collecting section 10 may be provided with a floating sludge taking-out section.

FIG. 2 is a partial sectional view showing such an embodiment. In this embodiment, the floating sludge extraction passage 17 is connected so as to transfer the floating sludge from the solid-liquid separating section 9 to the gas collecting section 10, and the crushing pump 27 of the submerged type is the gas collecting section 10.
It is provided near the liquid surface of. In the above apparatus, the floating sludge that has floated to the solid-liquid separation unit 9 is taken out from the floating sludge taking-out unit 14 and is taken up by the gas lift 16 in the floating sludge taking-out path 17
And is transferred to the gas collection unit 10. Gas collection section 1 here
It is crushed by the crushing pump 27 together with the floating sludge that floated at 0, and the crushed sludge is settled or returned to the reaction section 11 as it is. In this embodiment, the structure is simple.

FIG. 3 is a partial sectional view showing another embodiment. In this embodiment, the lower end of the gas introduction pipe 22 serves as a chute-shaped enlarged opening and is arranged on one end of the gas trap 21. In the above apparatus, the gas trapped in the gas trap 21 is stored in a compressed state, and when the pressure rises, a large amount of gas is intermittently released, and this gas is introduced into the gas lift 16 from the gas introduction pipe 22. Therefore, sludge can be effectively transferred with a small amount of gas.

FIG. 4 is a partial sectional view showing still another embodiment. In this embodiment, a gas lift 16 and a floating sludge take-out path 17 are attached to a gas trap 21 provided in the gas collecting section 10 to communicate with an external floating sludge tank 25. The solid-liquid separation unit 9 is also provided with the floating sludge take-out unit 14, the downcomer pipe 15, the gas lift 16, and the floating sludge take-out passage 17 shown in FIG. 1 or 2. In the above apparatus, the rising gas of the gas collection unit 10 is collected in the gas trap 21 and when the gas lift 16 is lifted, the floating sludge of the gas collection unit 10 is sent to the floating sludge extraction passage 17 and transferred to an external floating sludge tank. To do.
Thereby, the floating sludge in the gas collection part 10 can also be efficiently taken out and crushed.

FIG. 5 is a partial sectional view showing a gas lift according to another embodiment. In this embodiment, the gas lift 16
The gas trap 21 and the gas trap 21 are integrated via the liquid sealing portion 30. In this device, the gas trapped in the gas trap 21 is intermittently discharged in large amounts at a constant pressure, and the liquid sealing part 3
0 and the sludge in the gas lift 16 are pushed up, the floating sludge in the gas collection part 10 is sucked up as it goes, and this is repeated.
As a result, the floating sludge can be transferred with a small amount of gas.

[0040]

As described above, according to the present invention, the floating sludge floating in the anaerobic reaction tank is transferred by the gas lift utilizing the generated gas, so that the floating sludge can be transferred efficiently without power. As a result, the floating sludge can be crushed to recover the sedimentation property and returned, and the anaerobic treatment can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an anaerobic treatment apparatus according to an embodiment.

FIG. 2 is a partial cross-sectional view of an apparatus according to another embodiment.

FIG. 3 is a cross-sectional view of a portion of the device of another embodiment.

FIG. 4 is a partial cross-sectional view of the apparatus of another embodiment.

FIG. 5 is a sectional view of a gas lift according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anaerobic reaction tank 2 Processed liquid inflow part 3 Processed liquid introduction path 4 Cover 5, 5a Gas chamber 6 Gas extraction path 7, 7a Liquid chamber 8a, 8b Solid-gas separation member 9 Solid-liquid separation part 10 Gas collection part 11 Reaction part 12 Communication passage 13 Sludge blanket 14 Flotation sludge extraction part 15 Downcomer pipe 16 Gas lift 17 Flotation sludge extraction route 18 Treated liquid extraction part 19 Treated liquid removal route 20 Baffle 21 Gas trap 22 Gas introduction pipe 25 Floating sludge tank 26 Equalization pipe 27 Crushing pump 28 Sludge return path

Claims (1)

[Claims] 1. An anaerobic reaction tank having a reaction part in which a sludge blanket made of granulated sludge containing anaerobic microorganisms is formed, and an inflow part for liquid to be treated at the bottom, and an upper part of the reaction part. A solid-gas separation member that is installed so as to separate the solid-liquid separation unit and the gas collection unit, a communication passage that connects the lower part of the solid-liquid separation unit and the reaction unit, and the vicinity of the liquid surface of the solid-liquid separation unit Of the treated liquid, a solid-liquid separation unit and / or a floating sludge removal unit provided in the gas collection unit, and a crushing device that crushes the floating sludge extracted from the floating sludge extraction unit and returns it to the reaction unit. An anaerobic treatment device comprising: a gas lift that transfers the floating sludge from the floating sludge extraction unit to the shredding device using the gas collected in the gas collection unit.