WO2012165597A1

WO2012165597A1 - Waste water treatment apparatus

Info

Publication number: WO2012165597A1
Application number: PCT/JP2012/064220
Authority: WO
Inventors: 卓巳小原; 正彦堤; 伸行足利; 山本　勝也; 田村　博; 納田　和彦; 均中沢; 幸男川口; 敏一橋本; 幸志 ▲辻▼
Original assignee: 株式会社東芝; 日本下水道事業団
Priority date: 2011-06-01
Filing date: 2012-05-31
Publication date: 2012-12-06
Also published as: CN103889907A; JP2012250159A; CN103889907B; JP5813377B2

Abstract

Provided is a waste water treatment apparatus that can sufficiently prevent granules formed from aggregations of anaerobic microorganisms from flowing from a reactor. The waste water treatment apparatus (1) is provided with: a reactor main unit (21a) having an introduction opening in the bottom thereof; a supply device (3) that generates a rising flow of waste water; an aggregate layer (22) formed from accumulation of granules (30) in the lower part of the reactor main unit (21a); a carrier (14) that can support anaerobic microbes; an elimination device (27, L2) that eliminates waste water above the carrier (14) from the reactor main unit (21a); and a gas-solid-liquid separation device (10A) with which granules (32) with attached bubbles are introduced toward a surface boundary (15), the granules (30) and the bubbles separated, and the granules (30) that have been separated from the bubbles guided from the surface boundary (15) to an area sandwiched by the aggregate layer (22) and carrier (14) without coming into contact with the carrier (14).

Description

Wastewater treatment equipment

Embodiments described herein generally relate to a wastewater treatment apparatus that includes an anaerobic reactor and purifies organic wastewater such as sewage, agricultural wastewater, and factory wastewater with anaerobic microorganisms.

As shown in FIG. 8, in the conventional waste water treatment apparatus 100 using anaerobic microorganisms, the waste water as raw water is driven by a pump 3 to drive the anaerobic reactor 121 from the raw water supply source 2 through the water pipe L1. Introduce to the bottom. The reactor 121 contains anaerobic microorganisms aggregated in a granular shape in addition to water. Granules composed of anaerobic microorganisms (hereinafter “granule” means “granules composed of anaerobic microorganisms” unless otherwise stated) are retained at the bottom of the reactor 121 and flow. Aggregate layer 122 as a floor is formed.

When the wastewater introduced into the reactor 121 comes into contact with anaerobic microorganisms, organic pollutants in the wastewater are decomposed by the purification function of the microorganisms. In this decomposition reaction, as described in paragraph 0044 of JP-A-2009-028720, high-molecular organic pollutants such as carbohydrates, fats or proteins are converted into fatty acids according to the following formula (1) by acid-fermenting bacteria. It is decomposed into (RCOOH), amino acid (RCH (NH ₂ ) COOH) and the like, and further decomposed into acetic acid (CH ₃ COOH) according to the following formula (2). Then, acetic acid, by methane fermentation bacteria, is decomposed into methane (CH ₄₎ and carbon dioxide (CO ₂₎ according to the following equation (3).

The water that has passed through the aggregate layer 122 forms a supernatant 123 above the aggregate layer 122. In the reactor 121, a support 124 and a string-like carrier 125 formed by attaching a large number of fibers to a string in a brush shape are installed. The carrier 125 is supported by the support 124 so as to be immersed in the supernatant 123. A part of the anaerobic microorganisms carried from the aggregate layer 122 by the flow of water is attached to these carriers 125, and fine granules are formed. The organic pollutant that has not been decomposed in the aggregate layer 122 is decomposed by contact with the anaerobic microorganisms supported on the carrier 125.

Thereafter, the water reaches the overflow section 127 provided in the anaerobic reactor 121. The water overflowing from the overflow section 127 is discharged to the device 4 through the water pipe L2 for the next process.

The above-described wastewater treatment equipment is likely to cause outflow of the reactors due to bubbles adhering to suspended matter (Suspended Solids: SS) derived from granule or raw water. Granules and suspended solids that flow out of the reactor reduce the quality of the water as the final product. This will be described in detail below.

The granules of the aggregate layer 122 have a particle diameter of, for example, 1 to 10 mm, and the sedimentation speed thereof is, for example, 1 to 20 m / h or more. Therefore, if the upward flow speed of water in the reactor 121 is equal to or lower than the sedimentation speed of the granules, the granules are not released from the aggregate layer 122.

On the other hand, the minute granule produced by breaking the granule has a particle diameter of 0.1 to 1 mm, for example, and has a lower sedimentation speed than the granule of the aggregate layer 122. Therefore, even if the relatively large granules are not released from the aggregate layer 122, the minute granules can be released from the aggregate layer 122. However, such fine granules adhere to the carrier 125. Therefore, the amount of anaerobic microorganisms that normally flow out of the reactor 121 is small.

However, when the reactions of the formulas (1) to (3) are promoted in the aggregate layer 22, a large amount of methane gas and CO ₂ gas is generated. A large amount of bubbles made of these gases adhere to the above-mentioned granules and floating substances derived from raw water remaining undecomposed in the lower part of the reactor 121. The bubbles also adhere to the fine granules carried on the carrier 125.

Granules, microgranules and suspended solids behave as though the specific gravity is reduced when a large amount of bubbles are attached. That is, the sedimentation speed is lowered, and the rising linear speed is very large, for example, 0.01 to 1 m / sec (36 to 3600 m / h). When the ascending linear velocity increases in this way, the minute granules are not attached to the carrier 125 but are carried by the water overflowing the overflow section 127 and flow out of the reactor 121.

This is schematically shown in FIG.
Granules or suspended solids 30 to which no bubbles are attached rise in the waste water as indicated by an arrow 134 and come into contact with the fibers 125c fixed to the string 125b. Since the granule or suspended solid 30 has a relatively low ascending linear velocity, it adheres to the fiber 125c. In FIG. 9, the reference number 30b is given to the granule or suspended substance 30 adhering to the fiber 125c.

On the other hand, a bubble adhering granule or floating substance 32 formed by adhering bubbles, for example, bubbles 31 made of methane gas, to the granule or floating substance 30 also comes into contact with the fiber 125c. However, since the bubble adhering granule or suspended substance 32 has a high ascending linear velocity as described above, it does not adhere to the fiber 125c and flows out of the reactor 121.

If the granules and suspended matter 32 flow out of the reactor 121, the following problems may occur.

(A) The amount of the aggregate layer 22, that is, the amount of acid-fermenting bacteria and methane-fermenting bacteria in the reactor 121 is reduced, and the reactions of formulas (1) to (3) are suppressed. As a result, the organic pollutant purification process becomes insufficient, and the quality of the water discharged from the reactor 121 decreases.

(B) The floating organic pollutant derived from the raw water flows out of the reactor 121 before being solubilized by the hydrolysis reaction of the formula (1).

If a gas-solid-liquid separation zone is provided at the center of the reactor 121 and a part of the water above the gas-solid-liquid separation zone is returned to the bottom of the reactor 121 together with the granules, the granules flow out of the reactor 121. There is a possibility that it can be prevented. However, since granules and suspended solids to which bubbles of methane gas are attached have a high ascending linear velocity, the circulation system sufficiently prevents the granules and suspended matter from flowing out of the reactor 121. I can't.

An object of the present invention is to provide a wastewater treatment apparatus that can sufficiently prevent granules and suspended substances from flowing out of a reactor.

The wastewater treatment apparatus according to the embodiment generally includes a reactor main body having an inlet at the bottom, and supplies the wastewater into the reactor main body through the inlet, and causes the upward flow of the wastewater to flow into the reactor main body. A supply device to be generated, an aggregate layer in which a plurality of granules each comprising an aggregate of anaerobic microorganisms are retained in the lower part of the reactor main body, and the upper part of the reactor main body above the aggregate layer Air bubbles adhere to the carrier installed and capable of supporting the anaerobic microorganisms, the discharge device for discharging the waste water above the carrier from the reactor body, and the granules or fragments thereof released from the aggregate layer. The bubble adhering granule and the bubble adhering floating substance formed by adhering bubbles to the floating substance in the waste water, the waste water staying in the reactor main body and the upper part thereof Leading to the interface with the gas phase, where the bubble adhering granules are separated into the granules or fragments thereof and the bubbles, and the bubble adhering suspended substances are separated into the floating substances and the bubbles, The granule or a fragment thereof separated from the bubbles and the suspended substance separated from the bubbles are guided from the interface to a region sandwiched between the aggregate layer and the carrier without contacting the carrier. And a gas-solid-liquid separator.

The term “granule” refers to, for example, a bacterial aggregate in which anaerobic filamentous methane bacteria are intertwined into a granular shape having a diameter of several millimeters. The granule stays in the lower part of the waste water treatment device to form a fluidized bed, decomposes water-soluble organic substances contained in the waste water, and generates methane gas as a main by-product.

According to this waste water treatment apparatus, even when gas adheres to the granule and floats, a large amount of granule does not flow out of the reactor. It is possible to prevent the amount of attached anaerobic microorganisms such as acid-fermenting bacteria and methane-fermenting bacteria from becoming insufficient.

In addition, by suppressing the outflow of suspended solids derived from raw water, suspended solids can stay in the reactor for a long time and be decomposed by anaerobic microorganisms, and therefore without reducing the quality of the treated water Stable operation is possible.

The block diagram which shows the waste water treatment apparatus which concerns on 1st Embodiment. The schematic diagram for demonstrating the motion of the granule in the apparatus of FIG. The block diagram which shows the waste water treatment apparatus which concerns on 2nd Embodiment. The block diagram which shows the waste water treatment equipment which concerns on 3rd Embodiment. The block diagram which shows the waste water treatment apparatus which concerns on 4th Embodiment. The block diagram which shows the waste water treatment equipment which concerns on 5th Embodiment. The block diagram which shows the waste water treatment apparatus which concerns on 6th Embodiment. The block diagram which shows the conventional waste water treatment equipment. The schematic diagram for demonstrating the motion of the granule in the apparatus shown in FIG.

The wastewater treatment apparatus according to the embodiment generally includes a reactor main body, a supply apparatus, an aggregate layer, a carrier, a discharge apparatus, and a gas-solid-liquid separation apparatus. The reactor body has an inlet at the bottom. The supply device supplies waste water into the reactor main body through the inlet, and generates an upward flow of waste water in the reactor main body. The aggregate layer is formed by a plurality of granules each consisting of anaerobic microorganism aggregates staying in the lower part of the reactor body. The carrier is installed above the aggregate layer in the reactor main body, and can support anaerobic microorganisms. The discharge device discharges the waste water above the carrier from the reactor body. The gas-solid-liquid separator is a bubble-attached granule in which bubbles are attached to granules or fragments thereof released from the aggregate layer, and a bubble-attached suspended substance in which bubbles are attached to suspended matter in waste water. It leads to the interface between the waste water staying in the reactor body and the gas phase above it, where the bubble-attached granules are separated into granules or fragments thereof and the bubbles, and the bubble-attached suspended solids are suspended. Without contacting the carrier with granules or fragments thereof separated from the bubbles and suspended solids from the bubbles, to the region sandwiched between the aggregate layer and the carrier. Lead.

As described above, in this wastewater treatment apparatus, the gas-solid-liquid separation device guides the bubble-adhered granules and the bubble-adhered suspended solids to the gas-liquid interface in the reactor body. When the bubble adhering granules reach the gas-liquid interface, they are separated into granules or fragments thereof and bubbles. Similarly, when the bubble-attached suspended substance reaches the gas-liquid interface, the suspended substance and bubbles are separated. Granules separated from the bubbles or fragments thereof (hereinafter referred to as bubble separation granules) and suspended substances separated from the bubbles (hereinafter referred to as bubble separation floating substances) settle.

Also, the settling speeds of the bubble detachment granules and the bubble detachment suspended substances are much lower than the rising speeds of the bubble adhesion granules and the bubble adhesion suspended substances. Therefore, when a configuration in which the bubble detachment granule and the bubble detachment floating substance are in contact with the carrier is employed, if a large amount of the bubble adhesion granule and the bubble adhesion floating substance are generated, the carrier may be clogged. If the carrier is clogged, a large amount of granules and suspended solids may flow out of the reactor.

In this wastewater treatment device, the gas-solid-liquid separation device guides the bubble detachment granules and the bubble detachment suspended substances from the gas-liquid interface to the region sandwiched between the aggregate layer and the carrier without contacting the carrier. . Therefore, it is difficult to cause clogging in the carrier accompanying the sedimentation thereof.

Therefore, when the above configuration is adopted, it is possible to sufficiently prevent the granules and suspended substances from flowing out of the reactor.

The gas-solid-liquid separation apparatus partitions the internal space of the reactor body between the aggregate layer and the carrier, and allows the bubble-adhered granules and the bubble-adhered suspended solids to contact the carrier from the region to the interface. You may guide. In this case, the movement of bubble adhering granules and bubble adhering suspended substances to the gas-liquid interface is promoted.

The gas-solid-liquid separator includes, for example, a first guide member and a path forming member. The first guide member is, for example, installed between the aggregate layer and the carrier, and has a shape in which the lower surface tapers from below to above, and an opening is provided at a position corresponding to the top portion. A gap is formed between the edge of the reactor and the inner peripheral surface of the reactor body. For example, the path forming member extends upward from the opening of the first guide member, and the bubble-adhering granules and the bubble-adhering suspended solids float without contacting the carrier from the region below the first guide member to the interface. Form a path in which granules separated from bubbles or fragments thereof and suspended solids separated from bubbles settle without contacting the carrier from the interface to the above region, or bubble-attached granules and bubble-attached floating The ascending path where the substance floats from the region to the interface without contacting the carrier, the granule separated from the bubbles or fragments thereof, and the suspended matter separated from the bubbles contact the carrier from the interface to the region. And a sedimentation path that settles without doing so.

In this case, most of the bubble adhering granules and bubble adhering suspended solids are removed by the gas-solid-liquid separator in the process of rising in the reactor body. Although some of the bubble adhesion granules and the bubble adhesion floating substance rise through the gap between the outer edge of the first guide member and the inner peripheral surface of the reactor body, the amount does not install the guide member Less than the case. Further, at least a part of the bubble-adhered granules and the bubble-adhered suspended solids that have passed through the gap are captured by the carrier. Therefore, when the above configuration is adopted, the outflow of granules and suspended solids from the reactor main body can be more effectively suppressed.

The path forming member includes an inner cylinder that forms a settling path, and an ascending path that surrounds the inner cylinder and guides part of the drainage that has passed through the aggregate layer from the region below the first guide member to the interface. And an outer cylinder formed between the two. By adopting such a double tube structure, it is possible to increase the sedimentation speed of the granule from which bubbles are removed or a fragment thereof and the suspended matter from which bubbles are removed.

The gas-solid-liquid separator may further include a rectifying member protruding from the inner peripheral surface of the reactor main body toward the center between the aggregate layer and the outer edge of the first guide member. By adopting this configuration, it is possible to suppress a part of the bubble adhesion granules and the bubble adhesion suspended substance from passing through the gap between the outer edge of the first guide member and the inner peripheral surface of the reactor body. .

The gas-solid-liquid separation device is installed above the carrier, has a shape in which the lower surface tapers from the bottom to the top, and has an opening at a position corresponding to the top thereof. A second guide member that forms a gap with the inner peripheral surface may be further included. When this configuration is adopted, for example, the bubble-adhered granules and the bubble-adhered suspended solids that have passed through the gap can be guided to the gas-liquid interface, and the bubbles can be removed therefrom. In addition, it is possible to suppress the granule or suspended substance exfoliated from the carrier from flowing out of the reactor main body.

The gas-solid-liquid separation device is installed above the carrier, has a shape in which the lower surface tapers from the bottom to the top, and has an opening at a position corresponding to the top thereof. The guide member forming a gap with the inner peripheral surface, the granule separated from the bubbles or a fragment thereof, and the suspended matter separated from the bubbles settles without contacting the carrier from the interface to the region. And a path forming member that forms a settling path. When this configuration is adopted, it is possible to suppress the granule or suspended substance separated from the carrier from flowing out of the reactor main body.

The gas-solid-liquid separation device may further include a surrounding member surrounded so as to isolate the interface from the surroundings. In this case, for example, the discharge device discharges waste water outside the enclosure member from the reactor main body. Note that the position of the upper end of the enclosure member is higher than the position of the liquid level. By adopting this configuration, it is possible to more effectively suppress the outflow of granules and suspended substances from the reactor main body.

The waste water treatment apparatus may further include an aerobic reactor that receives waste water discharged from the reactor main body by the discharge device and treats the waste water with aerobic microorganisms. By adopting this configuration, organic wastewater such as sewage can be purified efficiently and at low cost, and wastewater standards regulated by law can be easily satisfied.

Hereinafter, a wastewater treatment apparatus according to an embodiment will be described with reference to the accompanying drawings.

(First embodiment)
A first embodiment will be described with reference to FIG.
The wastewater treatment apparatus 1 of this embodiment includes a raw water supply source 2, a pump 3, an anaerobic reactor 21, and an anaerobic treated water receiving unit 4. The raw water supply source 2 is a facility for temporarily storing the inflowing wastewater by flowing in organic wastewater such as sewage from a wastewater generation source (not shown). The outlet of the raw water supply source 2 and the inlet at the bottom of the anaerobic reactor 21 are connected via a water supply pipe L1, and the drainage is driven from the raw water supply source 2 through the water supply pipe L1 by driving the pump 3 as a supply device. 21 is introduced at the bottom. Further, the upper outlet of the anaerobic reactor 21 and the anaerobic treated water receiving unit 4 are connected via the water pipe L2, and the anaerobic treated water overflowed at the overflow section 27 passes through the water pipe L2 from the anaerobic reactor 21. It is supplied to the upper part of the anaerobic treated water receiving part 4 of the process. The overflow section 27 and the water supply pipe L2 constitute a discharge device that discharges the wastewater from the reactor 21. Further, the uppermost discharge port of the anaerobic reactor 21 and a methane gas processing device or a methane gas recovery and utilization device (not shown) are connected via a gas pipe L3. The gas is discharged to the methane gas processing device or the methane gas recovery and utilization device through the gas pipe L3.

The anaerobic reactor 21 has a reactor main body 21a including a conical lower portion and a cylindrical main body. The above-described drainage introduction port is provided at the lowermost part of the conical lower portion of the reactor main body 21a. The upper part of the reactor main body 21a is closed and the inside is sealed.

An overflow section 27 is provided in the upper part of the reactor main body 21a, and waste water overflowing from the overflow section 27, that is, treated water flows into the anaerobic treated water receiving section 4 through the water pipe L2. . The anaerobic treated water receiving unit 4 corresponds to a part of equipment for performing the process of the next process, and is an aerobic reactor having aerobic microorganisms, for example.

Further, the carrier 14 is disposed on the upper part of the reactor main body 21a. These carriers 14 have a string shape, and are suspended from a carrier support portion 24 arranged immediately below the overflow portion 27 with a space therebetween. Each carrier 14 includes a string 13 and a number of fibers 25 attached to the string 13 in a brush shape. Hereinafter, a region where the carrier 14 is installed in the internal space of the reactor main body 21a is referred to as a “carrier portion”.

The lower part of the internal space of the reactor body 21a is filled with anaerobic microorganism granules in an amount of about 1/4 (about 25%) of the effective volume of the anaerobic reactor (water volume when full). These granules form an aggregate layer 22. The agglomerate layer 22 is a fluidized bed containing granules 30 generated by putting a predetermined anaerobic microorganism into the reactor main body 21a, causing it to settle and agglomerating. When water containing floating contaminants such as sewage is used as raw water, floating substances flowing into the aggregate layer 21 through the pipe L1 accumulate. Since the granule 30 of the aggregate layer 22 and the suspended solid having a large specific gravity are larger than the specific gravity of water, it stays in the drainage at the lower part of the reactor main body 21a and forms a fluidized bed.

When organic components contained in the wastewater are decomposed by the methane fermentation bacteria and methane gas or carbon dioxide gas generated according to the formula (3) adheres to the granules 30 or suspended solids, these are the bubbles shown in FIG. The adhering granule and the bubble adhering floating substance 32 are obtained. The bubble adhesion granules and the bubble adhesion suspended substance 32 behave as if they have a specific gravity smaller than that of water. That is, the bubble adhering granules and the bubble adhering floating substance 32 float on the rising flow of the waste water in the reactor and easily flow out of the reactor. However, since this waste water treatment apparatus 1 has a gas-solid-liquid separation apparatus, which will be described later, the bubbles 31 are efficiently separated from the granules and suspended solids 30, and the granules into the treated water discharged from the reactor 21 and Mixing of floating substances can be suppressed.

The outflow prevention structure 10 as a gas-solid-liquid separator is provided in the reactor main body 21a. The outflow prevention structure 10 is installed above the aggregate layer 22 in the reactor main body 21a, and suppresses outflow of granules and suspended substances 30 to the outside of the reactor. Here, the outflow prevention structure 10 guides the bubble adhesion granules and the bubble adhesion floating substance 32 to the interface between the waste water staying in the reactor main body and the gas phase above it, and the bubbles are removed at this interface. The granulated particles or fragments thereof and the suspended substance are guided from the interface to a region sandwiched between the aggregate layer 22 and the carrier 14 without contacting the carrier 14. Furthermore, the outflow prevention structure 10 partitions the internal space of the reactor main body 21a between the aggregate layer 22 and the carrier part, and without bringing the bubble adhesion granules and the bubble adhesion floating substance 32 into contact with the carrier 14. Lead from the region to the interface.

The outflow prevention structure 10 includes a guide member 11, a path forming member 12, and a surrounding member 16.

The guide member 11 is installed between the aggregate layer 22 and the carrier part. The guide member 11 has a shape in which the lower surface tapers from the lower side to the upper side, and an opening is provided at a position corresponding to the top portion. The guide member 11 forms a gap between the outer edge and the inner peripheral surface of the reactor main body 21a.

The path forming member 12 extends upward from the opening of the guide member 11. The path forming member 12 is a granule or a fragment thereof separated from the bubbles, with the bubble adhering granules and the bubble adhering suspended substances 32 rising from the region below the guide member 11 to the gas-liquid interface without contacting the carrier 25. And a suspended substance separated from the bubbles form a path for sedimentation from the interface to a region below the guide member 11 without contacting the carrier 25.

The surrounding member 16 surrounds a part of the interface so as to isolate it from the surroundings. The surrounding member 16 is connected to the upper end of the path forming member 12.

Here, the guide member 11 is the lower conical portion 11 installed below the carrier portion, and the path forming member 12 is the upper cylindrical portion 12.

The lower conical part 11 has a conical shape that expands downward and opens at the top. The lower cone portion 11 is located immediately above the aggregate layer 22 and directly below the carrier portion. That is, the lower cone part 11 is installed in a space sandwiched between the aggregate layer 22 and the carrier part. The large-diameter portion of the lower cone portion 11 allows drainage to pass through the gap between the lower cone portion 11 and the reactor main body 21a, and prevents the bubble adhering granules and the suspended substance 32 from entering the carrier portion. Therefore, it is slightly smaller than the inner diameter of the cylindrical portion of the reactor main body 21a.

The upper cylindrical portion 12 has a lower end opening communicating with the opening of the lower conical portion 11, penetrating through the central portion of the carrier portion, and the upper liquid level 15, that is, the waste water staying in the reactor body 21 a and the upper portion thereof. It reaches the interface with the gas phase portion 28. Further, the upper end portion of the upper cylindrical portion 12 is continuous with the surrounding member 16. The enclosing member 16 is provided so as to protrude upward from the liquid level 15, and its upper end is positioned higher than the liquid level 15. The upper cylindrical portion 12 forms a granule and floating substance movement path that serves as the path 17 through which the bubble adhering granules and the floating substance 32 ascend and the path 19 through which the bubble separation granules and the floating substance 30 settle. Moreover, the surrounding member 16 forms the path | route 18 (refer FIG. 2) from which the bubble 31 isolate | separates from a granule and the suspended | floating matter 30 by stirring action.

In the anaerobic reactor 21, a gas phase part 28 is provided above the carrier part. The methane gas that has floated to the liquid surface 15 is released to the gas phase portion 28. The gas phase unit 28 communicates with a methane gas processing device (not shown) or a methane gas recovery device (not shown) via the uppermost outlet of the anaerobic reactor 21 and the gas pipe L3.

In the present embodiment, as illustrated, the inner diameter of the surrounding member 16 is the same as the inner diameter of the upper cylindrical portion 12, but other structures may be employed. For example, the inner diameter of the surrounding member 16 can be larger than the inner diameter of the upper cylindrical portion 12. In this case, the area of the liquid surface 15 surrounded by the enclosing member 16 is increased, so that the air bubbles 31 are likely to be detached from the bubble adhering granules and floating substances 32 that have floated on the liquid surface 15 as shown in FIG.

The operation of this embodiment will be described.
The sewage is introduced into the bottom of the anaerobic reactor main body 21 a from the raw water supply source 2 through the water supply pipe L 1 by driving the pump 3, and anaerobic microorganisms in the anaerobic microbial aggregate layer 22 introduced into the anaerobic reactor 21. By the granule 30, the organic pollutant in the sewage is decomposed according to the reactions of the formulas (1) to (3), and the waste water is purified.

As shown in FIG. 2, after the decomposition / purification treatment, a part of the granules 30 in the anaerobic microorganism aggregate layer 22 has a large amount of bubbles 31 made of methane gas adhering to the surface, and bubbles adhering granules 32. Become. When water containing floating contaminants such as sewage is used as raw water, suspended solids that flow in through the pipe L1 also accumulate in the aggregate layer 21, and some of the suspended solids become bubble-attached suspended solids. Moreover, since the specific gravity of this bubble adhesion granule and the suspended | floating matter 32 is smaller than water, it raises at a very high ascending linear velocity. In this process, the bubble adhering granules and the suspended matter 32 are collected by the lower cone portion 11 into the upper cylindrical portion 12 and reach the liquid level 15 above the anaerobic reactor 21 through the rising path 17 in the upper cylindrical portion 12. And floats to the liquid surface.

The bubble adhering granules and the suspended substance 32 are stirred at the liquid surface 15 and come into contact with the atmosphere of the gas phase portion 28 in the liquid surface 15 or the path 18 immediately below the liquid surface. As a result, the bubbles 31 made of methane gas are detached from the granules and the suspended matter 30.

The methane gas separated from the granules and the suspended solids 30 is temporarily stored in the gas phase portion 28, and the valve (not shown) of the gas pipe L3 is opened periodically or as necessary, so that the gas phase portion 28 is opened. To the above-mentioned methane gas treatment device or methane gas recovery and utilization device. The methane gas is detoxified in the methane gas processing apparatus, or is used as an electrical energy source or a thermal energy source.

In addition, the bubble detachment granules and the suspended substance 30 have a specific gravity larger than the original specific gravity, that is, the specific gravity of water 1.0. Accordingly, the bubble detachment granules and the suspended substance 30 settle through the sedimentation path 19 at the original sedimentation rate and settle on the aggregate layer 22 below the anaerobic reactor.

On the other hand, the purified water passes through a gap between the lowermost end of the lower conical part 11 and the inner peripheral surface of the reactor main body 21a, and then passes upward through the carrier part. It passes through the unit 27 and the water supply pipe L2 sequentially, is discharged from the anaerobic reactor 21 as anaerobic reactor treated water, and is sent to the apparatus 4 (for example, an aerobic reactor) in the next step.

Further, the granule and the suspended substance 30 that have passed upward through the gap between the inner peripheral surface of the reactor main body 21a come into contact with the carrier 14 when passing through the gap between the carriers 14. Thereby, the granules and the suspended solids 30 are captured by the carrier 14. Therefore, the granules and the suspended matter 30 stay inside the anaerobic reactor 21 without being accompanied by the treated water and flowing out of the reactor.

The effects of this embodiment are listed below.
(1) Installation and maintenance are easy by adopting a simple structure of the outflow prevention structure.
Since the outflow prevention structure 10 can be composed of a single plate in which the lower conical part 11 and the upper cylindrical part 12 are integrated, there is an advantage that simple installation such as hanging from the upper part is possible. Further, when such an outflow prevention structure 10 is employed, even if the outflow prevention structure 10 is damaged or the inside of the reactor main body 21a becomes dirty, even when maintenance or cleaning is required, the reactor Since the outflow prevention structure 10 can be pulled out from the reactor by opening the lid on the upper part of the apparatus 21, operations such as cleaning the outflow prevention structure 10 can be performed outside the reactor.

(2) Use of a string-like carrier facilitates installation and maintenance.
Since the structure in which the string-like carrier 14 is suspended from the upper part is employed, installation and maintenance are facilitated as in the above (1). Moreover, since the support | carrier 14 contains the fiber 25, it capture | acquires the granule 30 easily. Therefore, prevention of the outflow of the granules 30 to the outside of the reactor can be further promoted.

Note that the carrier is not limited to a string-like one. For example, meshes may be arranged above and below the carrier part, and a plastic carrier having a cylindrical shape, a spherical shape, a square shape, or the like may be installed in a region between the meshes.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. Note that a description of matters common to the present embodiment and the first embodiment will be omitted.

As shown in FIG. 3, in the wastewater treatment apparatus 1 A of the present embodiment, the path forming member has a double tube structure including an outer cylinder 12 and an inner cylinder 20. The outer cylinder 12 and the inner cylinder 20 are path forming members that form a rising path 41b in which the bubble adhering granules and the suspended matter 32 rise and a settling path 41d in which the bubble detaching granules 30 sink.

The outer cylinder 12 and the inner cylinder 20 form an ascending path 41b through which the bubble adhering granules and the suspended substance 32 ascend. Specifically, the outer cylinder 12 surrounds the inner cylinder 20 and forms a rising path 41b between them. The upper end portion of the outer cylinder 12 is connected to a surrounding member 16 having substantially the same diameter as that of the outer tube 12.

The inner cylinder 20 forms a sedimentation path 41d in which the bubble separation granules 30 settle. The inner cylinder 20 is inserted into the outer cylinder 12, the upper end is opened at the liquid level 15, and the lower end is opened in a region immediately above the aggregate layer 22. Further, the inner cylinder 20 is connected to an outflow prevention structure 10 A including the lower cone portion 11, the outer cylinder 12, and the surrounding member 16 by a connecting member (not shown).

The operation of this embodiment will be described.
The bubble adhering granules and suspended substances 32 are collected in the lower conical part 11 of the outflow prevention structure 10A by the buoyancy of the adhering bubbles 31 and pass from the path 41a through the path 41b of the outer cylinder 12 to the uppermost liquid level 15. Reach up to. Next, the bubble adhering granules and the floating substance 32 (black circles in the figure) are removed by the stirring action in the stirring path 41c, and become bubble separation granules and floating substances 30 (white circles in the figure). Flow into. Thereafter, the bubble detachment granules and the suspended substance 30 settle through the sedimentation path 41d and settle on the aggregate layer 22 at the bottom of the reactor.

The effect of this embodiment will be described.
In the present embodiment, by adopting a double tube structure composed of the outer cylinder 12 and the inner cylinder 20, the upward flow of the bubble adhering granules and the suspended matter 32 and the downward flow of the bubble detaching granules and the suspended matter 107 are achieved. Can be divided into separate routes and allowed to flow. Therefore, gas-liquid separation between granules and methane gas is promoted. As a result, the recovery efficiency of methane gas is increased. In addition, since the bubble adhering granules and suspended substances are reduced, the outflow of granules is suppressed, and the suspended substances stay in the anaerobic reactor for a long time. Therefore, the deterioration of the quality of treated water is further suppressed, and the decomposition of suspended substances (methane gasification) is further promoted.

Further, when the inner cylinder 20 is integrated with the outflow prevention structure 10A and a structure in which the inner cylinder 20 is suspended from the upper part is adopted, the installation and maintenance of the gas-solid-liquid separation device becomes easy.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. Note that a description of matters common to the present embodiment and the second embodiment will be omitted.

As shown in FIG. 4, in the wastewater treatment apparatus 1 B of the present embodiment, the second outflow prevention structure 50 is installed below the lower cone portion 11. The outflow prevention structure 50 is an annular member having a triangular cross section that protrudes from the inner peripheral surface of the reactor main body 21a toward the center. The outflow prevention structure 50 serves as a rectifying member. Specifically, the outflow prevention structure 50 prevents the bubble adhering granules and suspended substances 32 from entering the carrier 14 through a slight gap between the lower cone portion 11 and the reactor main body 21a. The outflow prevention structure 10B is the same as the outflow prevention structure 10A described with reference to FIG.

The operation of this embodiment will be described.
In the present embodiment, the outflow prevention structure 50 prevents the bubble adhering granules and the suspended substance 32 from entering the carrier portion through the path 41f between the lower cone portion 11 and the reactor main body 21a. Therefore, the bubble adhesion granules and the floating substance 32 are more effectively suppressed from flowing out of the reactor.

The effect of this embodiment will be described.
As described above, in this embodiment, the outflow prevention structure 50 suppresses the bubble adhering granules and the suspended matter 32 from entering the carrier portion through the path 41f between the lower cone portion 11 and the reactor main body 21a. To do. Therefore, the granule outflow is further suppressed, and the deterioration of the quality of the treated water is further suppressed.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. Note that a description of matters common to the present embodiment and the third embodiment will be omitted.

As shown in FIG. 5, in the wastewater treatment apparatus 1 C of the present embodiment, the gas-solid liquid separation apparatus further includes a third outflow prevention structure 51. The outflow prevention structure 51 is disposed below the lower cone portion 11 and parallel to the lower cone portion 11.

The effect of this embodiment will be described.
When the outflow prevention structure 51 is not present, the upward flow is bent as shown in the path 41h shown in FIG. 5 by the collision of the flow of the descending path 41e and the flow of the rising path 41g as shown in FIG. There is a case. When the bent path 41h is generated, there is a possibility that a part of the granule and the suspended substance flows out of the outflow prevention structure 10C through the path 41h.

In the apparatus 1C of the present embodiment, the path 41h is blocked by the outflow prevention structure 51, and the bubble adhering granules and suspended substances move upward through the path 41a. Therefore, it is possible to prevent the granules and suspended substances from flowing out more completely.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIG. Note that a description of matters common to the present embodiment and the fourth embodiment will be omitted.

As shown in FIG. 6, in the wastewater treatment apparatus 1 D of this embodiment, an aerobic reactor 60 is installed at the subsequent stage of the anaerobic reactor 21. The upper part of the aerobic reactor 60 is connected to the outlet of the anaerobic reactor 21 via the water supply pipe L2. The aerobic reactor 60 processes the waste water that has been processed by the anaerobic reactor.

A carrier support 61 is provided on the upper part of the aerobic reactor 60. A carrier 62 that is a string-like contact material is suspended from the carrier support portion 61. The carrier 52 carries an aerobic microorganism.

In the internal space of the reactor 60, the area below the area where the carrier 62 is installed is a lower gap 63. A tank 64 is connected to a portion of the side wall of the reactor 60 adjacent to the gap 63 via a water supply pipe L4. Water treated in the reactor 60 is supplied to the tank 64 via a water supply pipe L4.

The operation of this embodiment will be described.
In the anaerobic reactor 21, as described with reference to FIGS. 1 to 5, the organic pollutant in the sewage 1 is purified by the aggregate layer 22. Further, even when methane gas adheres to the granule and suspended matter and rises due to buoyancy, the gas-solid-liquid separation device suppresses the outflow of the granule and suspended matter, and is caused by the anaerobic microorganisms supported by the carrier 14. Purification is performed.

The water treated by the anaerobic reactor 21 is supplied from the anaerobic reactor 21 to the carrier 62 of the aerobic reactor 60 through the water supply pipe L4. Organic pollutants remaining in the treated water and dissolved hydrogen sulfide generated by sulfate-reducing bacteria which are one type of anaerobic microorganisms in the anaerobic reactor 21 are reduced by aerobic microorganisms supported by the carrier 62. Decomposes according to the reactions of formulas (4) and (5).

Organic pollutants + oxygen → carbon dioxide + water _{_{_{((C x H y O z}}} ) + (x + y / 4-z / 2) O 2 → xCO 2 + y / 2H 2 O) ... (4)
Hydrogen sulfide + oxygen → sulfuric acid + hydrogen ion (H ₂ S + 2O ₂ → SO ₄ + 2H ⁺ ) (5)
The effect of this embodiment will be described.
Since not only the anaerobic reactor 21 but also the aerobic reactor 60 purifies the organic pollutant as shown in the formula (4), water from which most of the organic pollutant is removed is obtained. Therefore, it can greatly contribute to water quality conservation of rivers, lakes, sewers, etc., from which water is discharged. Further, since the aerobic reactor 60 uses the string-like carrier 62, when a suspended substance contained in the sewage flows out or when microbacteria or bacterial groups of anaerobic microorganisms in the anaerobic reactor 21 are loaded, Even if the growth rate decreases or dies out due to fluctuations, contamination of sewage, etc., they are captured by the carrier 62. Therefore, they do not flow out into the treated water discharged from the aerobic reactor 60, and the quality of the treated water can be maintained well.

In this embodiment, a string-like carrier is used as an example of a carrier for an aerobic reactor and an anaerobic reactor, but any carrier may be used as long as microorganisms are easily attached thereto. For example, a plastic carrier having a cylindrical shape, a spherical shape, a square shape, or the like that is generally commercially available for water treatment may be used instead of the string shape.

(Sixth embodiment)
Next, a sixth embodiment will be described with reference to FIG. Note that a description of matters common to the present embodiment and the first embodiment will be omitted.

As shown in FIG. 7, in the wastewater treatment apparatus 1E of the present embodiment, the gas-solid liquid separation apparatus is an outflow prevention structure 10E including a guide member 11A, a path forming member 20A, and a surrounding member 16A.

The guide member 11A is installed above the carrier part. The guide member 11A has a shape in which the lower surface tapers from the lower side to the upper side, and an opening is provided at a position corresponding to the top part. 11 A of guide members form the clearance gap between an outer edge and the internal peripheral surface of the reactor main body 21a.

The path forming member 20A contacts the carrier 14 from the gas-liquid interface to the region sandwiched between the aggregate layer 22 and the carrier part, where the granules or fragments thereof separated from the bubbles and the suspended substance separated from the bubbles are in contact with each other. It forms a sedimentation path that settles without doing.

The surrounding member 16A surrounds a part of the gas-liquid interface so as to isolate it from the surroundings. The surrounding member 16A is connected to the opening of the guide member 11A.

Here, the guide member 11A is the upper conical portion 11A installed above the carrier portion, and the line forming member 20A is the lower cylindrical portion 20A.

The upper conical portion 11A has a conical shape that expands downward and opens at the top. The upper conical part 11A is located immediately above the carrier part. The opening of the upper cone portion 11 A is below the liquid surface 15. The large diameter portion of the upper conical portion 11A allows wastewater to pass through the gap between the upper conical portion 11A and the reactor main body 21a, and allows the bubble adhering granules and the suspended matter 32 to enter the overflow portion. In order to prevent this, it is slightly smaller than the inner diameter of the cylindrical portion of the reactor main body 21a.

The lower cylindrical portion 20A extends upward from the region sandwiched between the aggregate layer 22 and the carrier portion to the liquid level 15 so as to penetrate the opening of the upper conical portion 11A. There is a gap between the lower cylindrical portion 20A and the upper conical portion 11A at the position of the opening of the upper conical portion 11A. The lower cylindrical portion 20A forms paths 41i to 41k and settling

paths

41m and 41n. Further, the lower cylindrical portion 20 A forms a stirring path 41 l together with the surrounding member 16.

The surrounding member 16A surrounds a part of the liquid surface 15 so as to isolate it from the surroundings. The surrounding member 16A is connected to the opening of the upper conical portion 11A. The upper end of the upper cone portion 11 A is higher than the liquid level 15.

The operation of this embodiment will be described.
The bubble adhering granules and the suspended matter 32 pass through the aggregate layer 22 by the upward flow of the sewage, and then the liquid level via the path 41i, the carrier portion, the path 41k, or the path 41j. Reach 15 Here, the bubble adhering granules and the suspended matter 32 become the bubble leaving granules and the suspended matter 30 by removing the methane gas. The bubble detachment granules and the suspended substance 30 settle through the path 41m in the lower cylindrical portion 20A and return to the aggregate layer 22.

In the carrier part, anaerobic microorganisms adhering to the carrier 14 cause a decomposition reaction of organic substances that could not be decomposed by the aggregate layer 22. Methane gas is also generated during this decomposition process. In the case of the configuration shown in FIG. 1, the gas generated in the carrier part may cause the granules and suspended substances attached to the carrier 14 to peel off, thereby reducing the quality of the treated water. On the other hand, when the upper conical portion 11A is installed above the carrier portion, it is possible to suppress the floating substance or granules separated from the carrier from flowing out of the reactor.

Further, when the upper conical portion 11A and the lower cylindrical portion 20A are combined, the bubble adhering granules and the suspended matter 30 can be transported to the vicinity of the liquid surface 15 using their buoyancy and the upward flow of drainage. .

The technology described in this embodiment can be combined with the technology described in any of the first to fifth embodiments. For example, the wastewater treatment apparatus shown in any of FIGS. 1 and 3 to 6 may be provided with a guide member 11A, a path forming member 20A, and a surrounding member 16A. In this case, if a configuration is adopted in which the bubble detachment granules and the suspended solids 30 from which bubbles have been removed by being guided to the liquid level 15 by the guide member 11A are guided to the path forming member 12 or the inner cylinder 20 thereof, The path forming member 20A and the surrounding member 16A can be omitted.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

Claims

A reactor body having an inlet at the bottom;
A supply device for supplying wastewater into the reactor body through the inlet, and generating an upward flow of the wastewater in the reactor body;
An aggregate layer in which a plurality of granules each comprising an aggregate of anaerobic microorganisms are retained in the lower part of the reactor body;
A carrier that is installed above the aggregate layer in the reactor body, and is capable of supporting the anaerobic microorganisms;
A discharge device for discharging the waste water above the carrier from the reactor body;
A bubble adhering granule in which air bubbles adhere to the granule or a fragment thereof released from the aggregate layer, and a bubble adhering floating substance in which air bubbles adhere to the floating substance in the waste water are contained in the reactor body. To the interface between the waste water staying in the gas phase and the gas phase thereabove, where the bubble adhering granules are separated into the granules or fragments thereof and the bubbles, and The aggregate layer is separated from the interface without contacting the carrier with the granules or fragments thereof separated from the bubbles and the suspended matter separated from the bubbles. A wastewater treatment apparatus comprising a gas-solid-liquid separation device that leads to a region sandwiched by the carrier.
The gas-solid-liquid separation apparatus partitions the internal space of the reactor main body between the aggregate layer and the carrier, and without bringing the bubble adhesion granules and the bubble adhesion suspended solids into contact with the carrier. The waste water treatment apparatus according to claim 1, wherein the waste water treatment apparatus leads from the region to the interface.
The gas-solid-liquid separator is
Installed between the agglomerate layer and the carrier, the lower surface has a shape tapered from the bottom to the top, an opening is provided at a position corresponding to the top, the outer edge and the reactor body A first guide member forming a gap with the inner peripheral surface of
Extending upward from the opening of the first guide member, the bubble-adhering granules and the bubble-adhering suspended material float from the region below the first guide member to the interface without contacting the carrier; The granule or a fragment thereof separated from the bubble and the suspended solid separated from the bubble form a path for sedimentation without contacting the carrier from the interface to the region, or the bubble adhesion The ascending path where the granules and the bubble-adhering suspended substance float from the region to the interface without contacting the carrier, the granule separated from the bubbles or fragments thereof, and the suspended substance separated from the bubbles And a path forming member that forms a settling path that settles without contacting the carrier from the interface to the region. Or waste water treatment apparatus according to 2.
The path forming member guides the inner cylinder that forms the settling path and a part of the drainage that surrounds the inner cylinder and passes through the aggregate layer from the region below the first guide member to the interface. The waste water treatment apparatus according to claim 3, further comprising an outer cylinder that forms an ascending path with the inner cylinder.
The gas-solid-liquid separator further includes a rectifying member protruding from an inner peripheral surface of the reactor main body toward a center between the aggregate layer and the outer edge of the first guide member. The wastewater treatment apparatus according to 3 or 4.
The gas-solid-liquid separation device is installed above the carrier and has a shape in which a lower surface is tapered from below to above, an opening is provided at a position corresponding to the top, and an outer edge and the above-mentioned The wastewater treatment apparatus according to any one of claims 3 to 5, further comprising a second guide member that forms a gap with the inner peripheral surface of the reactor main body.
The gas-solid-liquid separator is
It is installed above the carrier, has a shape in which the lower surface tapers from below to above, and an opening is provided at a position corresponding to the top, and the outer edge and the inner peripheral surface of the reactor main body A guide member forming a gap therebetween;
A path forming member that forms a settling path in which the granules or fragments thereof separated from the bubbles and the suspended matter separated from the bubbles settle without contacting the carrier from the interface to the region. The waste water treatment apparatus of Claim 1.
The gas-solid-liquid separation device further includes an enclosure member that surrounds the interface so as to isolate it from the surroundings, and the discharge device discharges the waste water outside the enclosure member from the reactor main body. The waste water treatment apparatus of any one of.
The wastewater treatment apparatus according to any one of claims 1 to 8, further comprising an aerobic reactor that receives the wastewater discharged from the reactor main body by the discharger and treats the wastewater with aerobic microorganisms.