JP6960269B2 - Organic matter-containing water treatment method and organic matter-containing water treatment equipment - Google Patents

Description

The present invention relates to a method and an apparatus for treating organic matter-containing water, which biologically treats organic matter-containing water in a fluidized bed type reaction tank under anaerobic conditions.

Anaerobic fluidized bed water treatment, in which organic matter-containing water is biologically treated in a fluidized bed reaction tank under anaerobic conditions, involves adhering anaerobic microorganisms to the carrier and allowing the organic matter-containing water to flow in the reaction vessel, thereby combining the organic matter-containing water with the carrier. This is a processing method that enhances contact efficiency and enables stable and highly efficient processing. However, in this method, since it takes time for anaerobic microorganisms to adhere to the carrier, it takes a lot of time to recover the treatment capacity when the treatment efficiency is lowered or the treatment water quality is lowered. There is a problem that it is necessary.

For example, Patent Document 1 proposes a method of adding an anaerobic granule when the treatment is reduced in an anaerobic fluidized bed wastewater treatment. Since the anaerobic granule has a lower sedimentation rate than the carrier, the anaerobic granule is easily disassembled and dispersed under a sufficient flow state of the carrier, and tends to flow out of the reaction vessel in a short period of time. Therefore, although the reduction in treatment can be temporarily improved, it is necessary to add anaerobic granules multiple times in the long term.

Japanese Unexamined Patent Publication No. 2014-100679

Until now, there is no known method for efficiently recovering the treatment over a long period of time when the treatment of the anaerobic fluidized bed water treatment is reduced.

An object of the present invention is a method of biologically treating organic matter-containing water in a fluidized bed type reaction tank using an adherent carrier of anaerobic microorganisms under anaerobic conditions, in which the treatment is efficiently restored over a long period of time when the treatment is reduced. It is an object of the present invention to provide a method and an apparatus for treating organic matter-containing water.

The present invention is a method for treating organic matter-containing water by biologically treating organic matter-containing water in a fluidized bed type reaction tank under anaerobic conditions, in which anaerobic microorganisms including methane fermenting bacteria are formed into a biological film. The carrier to which the anaerobic microorganisms are attached as a biological film is formed in a storage tank separate from the reaction tank by passing water containing the organic matter to the biological treatment while flowing the carrier to which the organic matter-containing water is attached. This is a method for treating organic matter-containing water, in which the stored storage carrier is added to the reaction tank when the treatment is lowered so that the organic acid concentration of the treated water in the reaction tank becomes a predetermined value or more.

In the method for treating organic matter-containing water, it is preferable that the addition position of the storage carrier is on the outlet side of the inflow pump for flowing the organic matter-containing water into the reaction vessel.

In the method for treating organic matter-containing water, it is preferable that the storage tank is installed above the water surface of the reaction tank, and the storage carrier is naturally allowed to flow down and added to the reaction tank.

In the method for treating organic matter-containing water, it is preferable to replace a part of the storage carrier with a part of the carrier in the reaction tank when the treatment of the reaction tank is stable.

In the method for treating organic matter-containing water, it is preferable that the reaction tank has a stirrer for stirring the carrier.

In the method for treating organic matter-containing water, the carrier is preferably a gel-like carrier.

Further, the present invention is a treatment device for organic matter-containing water that biologically treats organic matter-containing water in a fluidized bed type reaction tank under anaerobic conditions, and anaerobic microorganisms including methane fermenting bacteria adhere in the form of a biological film. The reaction tank for biological treatment by passing the organic matter-containing water through the water while flowing the carrier, and the reaction tank for storing the carrier to which the anaerobic microorganisms are attached in the form of a biological film. Another storage tank and a control unit that controls to add the storage carrier in the storage tank to the reaction tank when the treatment is lowered so that the organic acid concentration of the treated water in the reaction tank becomes a predetermined value or more. It is a treatment device for organic matter-containing water.

In the organic matter-containing water treatment apparatus, the addition position of the storage carrier is preferably the outlet side of the inflow pump for flowing the organic matter-containing water into the reaction vessel.

In the organic matter-containing water treatment apparatus, it is preferable that the storage tank is installed above the water surface of the reaction tank, and the storage carrier is naturally allowed to flow down and added to the reaction tank.

In the organic matter-containing water treatment apparatus, it is preferable that the control unit controls so that a part of the storage carrier and a part of the carrier in the reaction tank are replaced when the treatment of the reaction tank is stable.

In the organic matter-containing water treatment device, it is preferable that the reaction tank has a stirrer for stirring the carrier.

In the organic matter-containing water treatment apparatus, the carrier is preferably a gel-like carrier.

In the present invention, in a method of biologically treating organic matter-containing water in a fluidized bed type reaction tank using an adherent carrier of anaerobic microorganisms under anaerobic conditions, it is possible to efficiently recover the treatment over a long period of time when the treatment is reduced. can.

It is a schematic block diagram which shows an example of the organic matter-containing water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows another example of the organic matter-containing water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows another example of the organic matter-containing water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows another example of the organic matter-containing water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows another example of the organic matter-containing water treatment apparatus which concerns on embodiment of this invention. It is a graph which shows the time-dependent change of the CODcr load (kg / m ^{3 / day) in an Example and a comparative example.}

Embodiments of the present invention will be described below. The present embodiment is an example of carrying out the present invention, and the present invention is not limited to the present embodiment.

An outline of an example of an organic substance-containing water treatment apparatus according to an embodiment of the present invention is shown in FIG. 1, and its configuration will be described.

The organic matter-containing water treatment device 1 shown in FIG. 1 includes a fluidized bed type reaction tank 10, a storage tank 12 separate from the reaction tank 10, and a control unit 32. In the fluidized bed type reaction tank 10, a carrier 26 to which anaerobic microorganisms are attached in the form of a biofilm is charged. In the storage tank 12, a storage carrier 28 to which anaerobic microorganisms are attached in the form of a biofilm is charged. The reaction tank 10 is for biological treatment by passing organic substance-containing water under anaerobic conditions while flowing the carrier 26 in the tank, and the storage tank 12 stores the storage carrier 28 and reacts. This is for adding the stored storage carrier 28 to the reaction tank 10 when the treatment of the tank 10 is lowered.

In the organic matter-containing water treatment apparatus 1 of FIG. 1, an organic matter-containing water inflow pipe 16 is connected to the organic matter-containing water inlet of the reaction tank 10 via an inflow pump 22, and the treated water outlet of the reaction tank 10 is treated. The water discharge pipe 18 is connected. In the treated water discharge pipe 18, a treated water quality measuring device 34 is installed as a treated water quality measuring means for measuring the water quality of the treated water. The fluidized bed type reaction tank 10 shown in FIG. 1 is a stirring type reaction tank, and is installed substantially vertically in the tank as a stirring means for stirring the draft tube 24 having an open top and bottom and the carrier 26 in the tank. , A stirring device 14 having a motor, a stirring blade, a shaft connecting the motor and the stirring blade, and the like may be provided. The stirring blade of the stirring device 14 is arranged in the draft tube 24. On the other hand, the outlet of the storage tank 12 and the storage carrier inlet of the reaction tank 10 are connected by a storage carrier supply pipe 20 via a pump 30. Further, the carrier outlet of the reaction tank 10 and the carrier inlet of the storage tank 12 may be connected by a carrier take-out pipe 40 via a pump 38. The control unit 32 is connected to the pumps 30 and 38 and the treated water quality measuring device 34 by an electrical connection or the like.

The method for treating the organic substance-containing water and the operation of the treatment device 1 according to the present embodiment will be described.

The organic matter-containing water, which is the water to be treated, flows into the reaction tank 10 through the organic matter-containing water inflow pipe 16 by the inflow pump 22. The carrier 26 is charged into the reaction vessel 10 before the start of water flow or after the start of water flow of the organic substance-containing water. In the reaction vessel 10, the carrier 26 and the organic substance-containing water are stirred by the stirring device 14, and the biological treatment is performed under anaerobic conditions (biological treatment step). In the present embodiment, since the stirring blade of the stirring device 14 is arranged in the draft tube 24, a downward flow is formed in the draft tube 24 by stirring by the stirring device 14, and the stirring blade is formed on the outer wall surface of the draft tube 24. An upward flow is formed between the reaction tank 10 and the inner wall surface. The treated water biologically treated in the reaction tank 10 is discharged to the outside of the system through the treated water discharge pipe 18. When such treatment is continued and the preset load is reached, the start-up of the biological treatment is completed, and thereafter, for example, while maintaining the load reached during the start-up period of the biological treatment, the organic matter-containing water Biological treatment (main treatment) is executed.

In the method for treating organic substance-containing water and the treatment apparatus 1 according to the present embodiment, the storage carrier 28 to which anaerobic microorganisms are attached in the form of a biofilm is reacted in advance in a normal time before the treatment efficiency of the reaction tank 10 deteriorates. The treatment performance in the reaction tank 10 is recovered by storing in a storage tank 12 separate from the tank 10 and adding the storage carrier 28 to the reaction tank 10 through the storage carrier supply pipe 20 by the pump 30 when the treatment of the reaction tank 10 is lowered. Let me. For example, the control unit 32 controls to add the storage carrier 28 in the storage tank 12 to the reaction tank 10 when the processing of the reaction tank 10 is lowered. The control unit 32 drives the pump 30 based on, for example, the measured value of the water quality of the treated water measured by the treated water quality measuring device 34, and the storage carrier 28 is added to the reaction tank 10. As a result, when the treatment of the anaerobic fluidized bed water treatment in the reaction tank 10 is reduced, the treatment can be efficiently recovered over a long period of time. It is slow to put a new carrier into the reaction tank 10 after the treatment efficiency of the reaction tank 10 deteriorates, and a storage carrier 28 to which anaerobic microorganisms are attached is prepared in advance during normal operation before the treatment is lowered. By adding the storage carrier 28 to the reaction tank 10 when the treatment of the reaction tank 10 is lowered, the treatment can be efficiently recovered and the stable treatment can be maintained for a long period of time.

[Anaerobic fluidized bed water treatment reaction tank form]
The flow bed type reaction tank 10 may be either an upward flow type or a stirring type, but the stirring type has high contact efficiency between the water to be treated and the carrier 26, a high fat concentration and suspended solids (SS). ) Stirring type is preferable because it can be treated even with organic substance-containing water having a concentration. The fluidized bed type reaction vessel 10 is not limited to the upward flow type and the stirring type, and may be of a type in which the carrier flows, and is not particularly limited.

The stirring device 14 is not particularly limited as long as it has a device configuration capable of stirring the carrier 26 in the fluidized bed type reaction tank 10. Examples of the stirring device 14 include a stirring device having a motor, a stirring blade, a shaft connecting the motor and the stirring blade, and the like. Since the reaction tank 10 has a stirring device for stirring the carrier 26, the carrier is as evenly as possible (as uniform as possible) in the reaction tank 10 when the carrier 26 is taken out from the reaction tank 10 and when the carrier 26 is taken into the reaction tank 10. Can be taken out and taken in.

It is preferable to install the draft tube 24 inside the stirring type reaction tank 10 from the viewpoint of improving the fluidity of the carrier 26, but it is not always necessary to install the draft tube 24. The draft tube 24 is a cylindrical tube such as a cylinder that is installed substantially vertically in the reaction vessel 10 and has openings at the top and bottom.

The treatment apparatus 1 of the present embodiment preferably includes, for example, a screen (not shown) installed so as to surround the treatment water outlet of the fluidized bed type reaction tank 10. This screen makes it possible to suppress the outflow of the carrier 26 from the fluidized bed type reaction vessel 10. Examples of the screen include a wedge wire screen, a wire mesh, a punching metal, and the like.

The treated water quality measuring device 34 may be any as long as it can measure the water quality of the treated water, and is not particularly limited. For example, a TOC (total organic carbon) measuring device, a COD (chemical oxygen demand) measuring device, and the like. Examples include a pH measuring device.

[Carrier]
The carrier on which the anaerobic microorganism is attached in the form of a biofilm may be any carrier conventionally used in the treatment of anaerobic organisms, and is not particularly limited. Examples of the carrier include a plastic carrier, a sponge-like carrier, a gel-like carrier, and the like. In particular, by using a gel-like carrier, methane-fermenting bacteria that do not produce high molecular weight polymers easily enter the pores of the three-dimensional network structure of the gel-like carrier, or adhere to the gel-like carrier due to the shape, charge, etc. Since it is effective for retaining the biological membrane and the fluidity of the carrier by stirring is high, a high load treatment is possible as compared with a plastic carrier and a sponge-like carrier. The gel-like carrier is not particularly limited, and examples thereof include a water-absorbent polymer gel-like carrier containing polyvinyl alcohol, polyethylene glycol, polyurethane, and the like.

The shape of the carrier 26 is not particularly limited, but a spherical or cubic (cube-shaped), rectangular parallelepiped, cylindrical or the like having a diameter of about 0.5 mm to 20 mm is preferable. In particular, a spherical or cylindrical gel-like carrier having a diameter of about 3 to 8 mm is preferable.

In order to form a fluid state inside the reaction vessel 10, the specific gravity of the carrier 26 is preferably at least 1.0, and the true specific density is 1.1 or more, or the apparent specific gravity is 1.01 or more.

The amount of the carrier 26 charged into the reaction vessel 10 is preferably in the range of 10 to 50% with respect to the volume of the reaction vessel 10. If the input amount of the carrier 26 is less than 10% with respect to the volume of the reaction tank 10, the reaction rate may decrease, and if it exceeds 50%, the carrier 26 becomes difficult to flow and may be blocked by sludge during long-term operation. The water to be treated may short-pass and the quality of the treated water may deteriorate.

The sedimentation rate of the carrier 26 is preferably 100 to 150 m / hr. If the sedimentation speed of the carrier 26 is less than 100 m / hr, the carrier 26 floats and easily flows out from the reaction tank 10, and if it exceeds 150 m / hr, the flow state deteriorates and the water to be treated may short-pass. , The energy of stirring may increase.

[Anaerobic microbial attachment carrier]
The biofilm is a membrane-like structure in which anaerobic microorganisms and products such as exopolysaccharides produced by anaerobic microorganisms are aggregated, and has a film thickness of at least 10 μm or more, preferably 20 μm or more. It has. The film thickness is the thickness from the surface of the carrier 26, and is an average value of 10 to 20 carriers 26. For products such as exopolysaccharides, the polysaccharides can be extracted from the biofilm using alkali, and the sugar concentration in the extract can be measured by the Anthrone method. Products such as exopolysaccharide have adhesiveness and are considered to affect the adhesiveness of the biofilm. For example, it is preferably present in the biofilm at 20 ppm or more, preferably at 50 ppm or more. It is more preferable to do so.

[Operating conditions of reaction tank]
In the present embodiment, when the organic substance-containing water is biologically treated, the pH of the organic substance-containing water is preferably in the range of 6.0 to 8.0, more preferably in the range of 6.5 to 7.5. The pH of the organic matter-containing water is adjusted, for example, by supplying the pH adjuster from the pH adjuster supply pipe (not shown) to the raw water tank (not shown) storing the organic matter-containing water. If the pH of the organic matter-containing water is out of the above range, the decomposition reaction rate of the organic matter by the biological treatment may decrease.

Examples of the pH adjuster include an acid agent such as hydrochloric acid and an alkaline agent such as sodium hydroxide, and are not particularly limited. Further, the pH adjusting agent may be, for example, sodium bicarbonate having a buffering action, a phosphate buffer solution, or the like.

In the present embodiment, it is preferable to add a nutrient to the organic matter-containing water, for example, from the viewpoint of maintaining good decomposition activity of anaerobic microorganisms when biologically treating the organic matter-containing water. The nutritional supplement is not particularly limited, and examples thereof include a carbon source, a nitrogen source, a phosphorus source, and other inorganic salts (salts such as Ni, Co, and Fe).

In the present embodiment, it is preferable to adjust the water temperature of the fluidized bed type reaction vessel 10 so as to be 20 ° C. or higher. Generally, when the temperature is lower than 20 ° C., the decomposition reaction rate tends to decrease. The method for adjusting the temperature of the water temperature in the reaction tank 10 is not particularly limited. For example, a heating device such as a heater is installed in the reaction tank 10 and the water temperature in the reaction tank 10 is adjusted by the heat of the heater or the like. Examples include a method of adjustment.

[Storage tank]
The storage carrier 28 to which anaerobic microorganisms are attached in the form of a biofilm is stored in the storage tank 12. The storage carrier 28 to which the anaerobic microorganisms are attached in the form of a biofilm is secured from, for example, a acclimation device or the like in which the carrier to which the anaerobic microorganisms are not attached is immersed in organic matter-containing water and acclimated for a long period of time. Further, for example, it is secured from a treatment device of another system that performs anaerobic treatment of organic matter-containing water using a carrier for a long period of time. Alternatively, it is secured by withdrawing a part of the carrier from the reaction vessel 10. For example, the carrier 26 in the reaction tank 10 may be pulled out through the carrier take-out pipe 40 by the pump 38 and added to the storage tank 12.

The amount of the storage carrier 28 stored in the storage tank 12 is preferably equivalent to 30 to 100%, more preferably 70 to 100% of the amount (volume) of the carrier 26 held in the reaction tank 10.

The material, shape, specific gravity, settling speed, and the like of the carrier used as the storage carrier 28 may be the same as those of the carrier 26.

As the pump 30 for adding the storage carrier 28 to the reaction tank 10, a normal pump can be used, but in order to suppress damage to the storage carrier 28 and peeling of the biological film adhering to the carrier, the rotational volume Type pumps, tube pumps, air lift pumps and the like are preferable.

In the present specification, "when the treatment is lowered" means (1) a state in which the organic matter removal rate is reduced by 30% or more as compared with the stable organic matter removal rate, and (2) 30 as compared with the treated water quality in the stable state. The quality of the treated water has deteriorated by% or more, (3) the organic acid concentration of the treated water has reached 150 mg / L or more, and (4) the pH of the organic matter-containing water is out of the range of 6.5 to 7.5. Refers to at least one state of the state. In addition, "when the treatment is stable" means (1) a state in which the organic matter removal rate is 70% or more, (2) a state in which the treated water quality is less than 30% of the raw water concentration, and (3) an organic acid concentration in the treated water is 150 mg. It refers to at least one state of less than / L, and (4) a state in which the pH of the organic matter-containing water is in the range of 6.5 to 7.5. For example, the control unit 32 may determine "when the treatment is low" and "when the treatment is stable" based on the measured values of the water quality such as TOC, COD, and pH of the treated water measured by the treated water quality measuring device 34. ..

If the storage carrier 28 to which the anaerobic microorganisms are attached in the form of a biofilm is not carefully stored and transferred, the biofilm may peel off from the carrier. For example, as shown in FIG. 1, when the storage carrier 28 is transferred from the storage tank 12 to the reaction tank 10, if a pump 30 or the like is used, the anaerobic microorganisms adhering to the surface of the storage carrier 28 are easily peeled off, and the carrier It may also be damaged. Therefore, for example, as shown in FIG. 2, it is preferable to add the storage carrier 28 on the outlet side of the inflow pump 22 or the like that allows the organic matter-containing water to flow into the reaction tank 10. In the treatment apparatus 3 shown in FIG. 2, the storage carrier supply pipe 20 from the outlet of the storage tank 12 is a valve between the outlet side of the inflow pump 22 in the organic matter-containing water inflow pipe 16 and the organic matter-containing water inlet of the reaction tank 10. It is connected via 36. Further, the carrier outlet of the reaction tank 10 and the carrier inlet of the storage tank 12 may be connected by a carrier take-out pipe 44 via a pump 42. The control unit 32 is connected to the treated water quality measuring device 34, the valve 36, and the pump 42 by electrical connection or the like. In the treatment apparatus 3 shown in FIG. 2, the addition position of the storage carrier 28 is installed on the outlet side of the inflow pump 22 of the reaction tank 10, and the peeling of the biofilm is suppressed together with the organic substance-containing water extruded by the inflow pump 22. This is a method of adding to the reaction vessel 10. For example, the control unit 32 controls the opening and closing of the valve 36 based on the measured value of the water quality of the treated water measured by the treated water quality measuring device 34, and the storage carrier 28 is the storage carrier supply pipe 20, the organic substance-containing water inflow pipe. It is added to the reaction vessel 10 through 16.

Alternatively, as shown in FIG. 3, it is preferable that the storage tank 12 is installed above the water surface of the reaction tank 10 and the storage carrier 28 is naturally allowed to flow down and added to the reaction tank 10. In the processing apparatus 5 shown in FIG. 3, a storage carrier supply pipe 20 from the outlet of the storage tank 12 installed above the water surface of the reaction tank 10 is connected to the storage carrier inlet above the reaction tank 10 via a valve 36. ing. Further, the carrier outlet of the reaction tank 10 and the carrier inlet of the storage tank 12 may be connected by a carrier take-out pipe 44 via a pump 42. The control unit 32 is connected to the treated water quality measuring device 34, the valve 36, and the pump 42 by electrical connection or the like. In the processing apparatus 5 shown in FIG. 3, a storage tank 12 for storing the storage carrier 28 is installed above the water surface of the reaction tank 10, and the storage carrier 28 is naturally allowed to flow down and added to the reaction tank 10 to form a biofilm. This is a method of suppressing peeling and adding to the reaction vessel 10. For example, the control unit 32 controls the opening and closing of the valve 36 based on the measured value of the water quality of the treated water measured by the treated water quality measuring device 34, and the storage carrier 28 is added to the reaction tank 10 through the storage carrier supply pipe 20. Will be done.

According to the configurations shown in FIGS. 2 and 3, when the storage carrier 28 is added to the reaction tank 10, the biofilm adhering to the storage carrier 28 can be added to the reaction tank 10 without peeling as much as possible.

It is preferable to adjust the amount of the storage carrier 28 added according to the state of decrease in the treatment of the reaction vessel 10. For example, when the organic matter removal rate is reduced by 40% as compared with the stable organic matter removal rate, the storage carrier 28 is used. Is added in an amount of 40% of the amount of the holding carrier in the reaction vessel 10. If the amount of the retained carrier in the reaction vessel 10 becomes excessive, the fluidity of the carrier 26 may be poor. Therefore, it is preferable to withdraw the carrier 26 from the reaction vessel 10 in an amount equivalent to the amount of the stored carrier 28 added. .. In this case, it is more preferable to install two or more storage tanks 12 and separate the carrier 26 drawn from the reaction tank 10 from the stored storage carrier 28.

When the storage carrier 28 to which the anaerobic microorganisms are attached is stored in the storage tank 12 for a long period of time, the activity of the microorganisms may decrease. Therefore, when the treatment of the reaction tank 10 is stable, it is preferable to replace a part of the carrier 26 in the reaction tank 10 with a part of the storage carrier 28 in the storage tank 12 to maintain the activity of the microorganism. For example, the control unit 32 controls so that a part of the storage carrier 28 and a part of the carrier 26 in the reaction tank 10 are replaced when the processing of the reaction tank 10 is stable. In the treatment device 1 of FIG. 1, for example, the control unit 32 drives the pump 30 and the pump 38 based on the measured values of the water quality of the treated water measured by the treated water quality measuring device 34, and the storage carrier in the storage tank 12 is driven. A part of 28 and a part of the carrier 26 in the reaction tank 10 are replaced. In the treatment devices 3 and 5 of FIGS. 2 and 3, for example, the control unit 32 controls the opening and closing of the valve 36 based on the measured value of the water quality of the treated water measured by the treated water quality measuring device 34, and the pump 42 is driven. Then, a part of the storage carrier 28 in the storage tank 12 and a part of the carrier 26 in the reaction tank 10 are replaced. The storage carrier inlet and the carrier outlet of the reaction tank 10 are separated from each other in the reaction tank 10 so that the carrier 26 to be taken out and the storage carrier 28 to be added are not mixed as much as possible in consideration of the flow direction in the reaction tank 10. It is preferable to arrange them. As for the pumps 38 and 42 for adding the carrier 26 in the reaction tank 10 to the storage tank 12, the same pump as the pump 30 can be used.

It is preferable that the carrier 26 held in the reaction tank 10 is replaced with the storage carrier 28 held in the storage tank 12 in, for example, 3 to 14 days. Normally, in the operation management of anaerobic treatment, it is common to check the treatment status every 1 to 3 days. Therefore, if the carrier replacement frequency is less than 3 days, the reaction tank 10 will be replaced when the treatment of the reaction tank 10 is lowered. Both the carrier 26 held in the storage tank 12 and the storage carrier 28 held in the storage tank 12 may be affected by the deterioration of the processing performance. On the other hand, if the carrier replacement frequency exceeds 14 days, the activity of the anaerobic microorganisms on the stored carrier 28 begins to decrease, which may lead to a decrease in processing performance.

Compared with other carriers, the gel-like carrier has a high retention ability of anaerobic microorganisms and the elasticity of the carrier itself. Therefore, when the carrier is transferred between the storage tank 12 and the reaction tank 10, the biofilm It is possible to suppress peeling and damage to the carrier.

[Discharge containing organic matter]
The organic substance-containing water to be treated in the organic substance-containing water treatment method and the treatment apparatus 1 of the present embodiment is, for example, an organic substance (fat, oil, suspension) discharged from a food manufacturing factory, an electronic industry factory, a pulp manufacturing factory, a chemical factory, or the like. Wastewater containing turbid substances and organic substances other than fats and oils and suspended substances.

The stirring type treatment device can treat organic matter-containing water having a high fat and oil concentration and SS concentration, but the normal hexane extract substance concentration (fat and fat concentration) of the target organic matter-containing water is, for example, 100 mg / L or more. It is preferably 150 mg / L or more. The SS concentration is, for example, 100 mg / L or more, preferably 200 mg / L or more.

[Other Embodiment 1]
The organic matter-containing water treatment apparatus according to the present embodiment is provided with a plurality of reaction tanks 10 (for example, the first reaction tank 10a and the second reaction tank 10b in the example of FIG. 4) as shown in FIG. 4, respectively. The storage carrier 28 to which the biofilm is attached may be added from the storage tank 12 to the reaction tank 10. In this case, the carrier 26 drawn from the first reaction tank 10a and the second reaction tank 10b, respectively, may be replaced with the storage carrier 28 of the storage tank 12.

[Other Embodiment 2]
Further, as shown in FIG. 5, a plurality of reaction tanks 10 (for example, the first reaction tank 10a and the second reaction tank 10b in the example of FIG. 5) were provided, and (1) the treatment of the second reaction tank 10b was reduced. When it is determined, the carrier 26 to which the biofilm in the first reaction tank 10a is attached is added to the second reaction tank 10b, and (2) next, the storage carrier 28 to which the biofilm in the storage tank 12 is attached is added to the first reaction. It may be added to the tank 10a. In this case, the carrier 26 drawn from the second reaction tank 10b may be added to the storage carrier 28 of the storage tank 12.

In this case, for example, the operating conditions such as the load are higher in the second reaction tank 10b than in the first reaction tank 10a (for example, the maximum condition), and in the first reaction tank 10a, the conditions are lower than the second reaction tank 10b (relaxation condition). ). Microorganisms involved in anaerobic treatment are vulnerable to environmental changes, are inhibited under overload conditions, and their activity tends to decrease. Therefore, the treatment reduction phenomenon appears from the second reaction tank 10b. The decrease is smaller than that of the second reaction tank 10b. Since a carrier having a higher activity than that of the storage tank 12 is present in the first reaction tank 10a, the amount of the carrier transferred from the storage tank 12 is smaller by transferring the carrier to the second reaction tank 10b (for example, the maximum condition). Sufficient effect can be obtained. After the transfer from the first reaction tank 10a to the second reaction tank 10b, the carrier deficient in the first reaction tank 10a may be replenished from the storage tank 12. Since the storage carrier 28 in the storage tank 12 is a carrier having low activity, the activity can be recovered more smoothly by putting it in the first reaction tank 10a under the relaxed conditions.

For example, the carrier 26 to be returned is charged from the upper part of the storage tank 12 so that the storage carrier 28 stored in the storage tank 12 and the carrier 26 returned from one or more reaction tanks 10 to the storage tank 12 are not mixed as much as possible. However, it is preferable that the stored carrier 28 to be transferred is extracted from the lower part while preventing the carriers from being mixed up and down.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

(1) Comparative test of storage carrier addition method and anaerobic granule addition method A new spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm) to which anaerobic microorganisms are not attached, assuming a decrease in treatment. , Specific gravity 1.025, sedimentation rate 4 cm / sec) was filled by 24 to 30% with respect to the volume of the reaction vessel (acrylic reaction vessel having a volume of 600 mL) (assuming that the treatment cannot be performed at all). The organic matter-containing water to be treated was simulated wastewater from a food factory (CODcr = 2500-3000 mg / L) containing sucrose and bonito extract as main components.

[Comparison example]
10% of the volume of the reaction vessel was charged with anaerobic granules. The carrier and anaerobic granules were allowed to flow by stirring the inside of the reaction vessel with a stirrer. The results are shown in FIG.

As shown in FIG. 6, in the comparative example, since the anaerobic granules gradually flowed out from the reaction tank from the start of the operation, it became difficult to set the load appropriately, and the load increased after the 40th day of the operation. It was stagnant. Finally, the load reached on the 80th day of operation was about 6 kg / m ³ / day.

[Example 1]
Storage carrier (Spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific gravity 1.025, sedimentation rate 4 cm / sec, anaerobic microorganisms adhere to the inside and surface of the carrier as a biofilm)) Was added at 1.5% of the volume of the reaction vessel, and no anaerobic granule was added. The other conditions were the same as in the comparative example. The results are shown in FIG.

As shown in FIG. 6, in Example 1, the anaerobic granules hardly flowed out from the reaction vessel as in the comparative example, and the amount of sludge retained in the reaction vessel did not change significantly, so that the load was gradually increased. The load reached on the 80th day of operation was about 10 kg / m ³ / day.

[Example 2]
Storage carrier (Spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific gravity 1.025, sedimentation rate 4 cm / sec, anaerobic microorganisms adhere to the inside and surface of the carrier as a biofilm)) Was added at 6% of the volume of the reaction vessel, and no anaerobic granule was added. The other conditions were the same as in the comparative example. The results are shown in FIG.

As shown in FIG. 6, in Example 2, the anaerobic granule hardly flowed out from the reaction vessel as in the comparative example, and the amount of sludge retained in the reaction vessel did not change significantly, so that the load was quickly increased. It was able to be raised and reached a load of about 18 kg / m ³ / day on the 70th day of operation.

As described above, it was found that the treatment can be quickly recovered by adding the storage carrier to the reaction tank when the treatment in the reaction tank is lowered.

(2) Comparison experiment of addition position of storage carrier When the storage carrier is put into the inlet side of the inflow pump of organic matter-containing water and transferred to the reaction tank, the storage carrier comes into contact with the propeller rotating at high speed inside the pump. Therefore, when the storage carrier is charged to the inlet side of the inflow pump and brought into contact with the propeller and charged into the reaction tank, and when it is charged to the outlet side of the inflow pump and charged into the reaction tank without contacting the propeller. The processing performance was compared.

In a 60 L volume acrylic reaction tank having a draft tube inside, a carrier (spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific density 1.025, sedimentation speed 4 cm /) was used using a stirrer. sec)) was flowed. The organic matter-containing water to be treated was organic matter-containing wastewater (CODcr concentration: 1,500 to 3,000 mg / L) discharged from a food manufacturing factory.

[Example 3]
Storage carrier (Spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific gravity 1.025, sedimentation rate 4 cm / sec, anaerobic microorganisms adhere to the inside and surface layer of the carrier as a biofilm)) Was charged into the inlet side of the inflow pump, brought into contact with the propeller, and then charged into the reaction vessel (filling rate: 30%). The CODcr removal rate was 9.8 kg / m ³ / day.

[Example 4]
Storage carrier (Spherical polyvinyl alcohol gel-like carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific gravity 1.025, sedimentation rate 4 cm / sec, anaerobic microorganisms adhere to the inside and surface layer of the carrier as a biofilm)) Was charged into the outlet side of the inflow pump and charged into the reaction vessel without contacting the propeller (filling rate: 30%). The CODcr removal rate was 17.3 kg / m ³ / day.

As described above, it was found that the addition position of the storage carrier is preferably the outlet side of the inflow pump that does not contact the propeller, rather than the inlet side of the inflow pump that contacts the propeller of the pump.

As described above, in the method of biologically treating organic matter-containing water in a fluidized bed type reaction tank using an adherent carrier of anaerobic microorganisms under anaerobic conditions by the method of Examples, when the treatment is reduced, it is efficient and over a long period of time. I was able to recover the processing.

1,3,5 Treatment equipment, 10 Reaction tanks, 10a 1st reaction tank, 10b 2nd reaction tank, 12 storage tanks, 14 stirrers, 16 organic substance-containing water inflow pipes, 18 treated water discharge pipes, 20 storage carrier supply pipes , 22 inflow pump, 24 draft tube, 26 carrier, 28 storage carrier, 30, 38, 42 pump, 32 control unit, 34 treated water quality measuring device, 36 valve, 40, 44 carrier take-out pipe.

Claims (12)

A method for treating organic matter-containing water in which organic matter-containing water is biologically treated under anaerobic conditions using a fluidized bed type reaction tank.
An anaerobic microorganism containing a methane-fermenting bacterium forms a biofilm and adheres to the reaction vessel while flowing a carrier, and the organic substance-containing water is passed through the reaction vessel for biological treatment.
In a storage tank different from the reaction tank, the carrier to which the anaerobic microorganisms are attached in the form of a biological film is stored, and when the treatment is lowered so that the organic acid concentration of the treated water in the reaction tank becomes a predetermined value or more, the said. A method for treating organic matter-containing water, which comprises adding the stored storage carrier to the reaction vessel. The method for treating organic matter-containing water according to claim 1.
A method for treating organic matter-containing water, wherein the storage carrier is added at the outlet side of an inflow pump for flowing the organic matter-containing water into the reaction vessel. The method for treating organic matter-containing water according to claim 1.
A method for treating organic matter-containing water, which comprises installing the storage tank above the water surface of the reaction tank, allowing the storage carrier to naturally flow down, and adding the storage carrier to the reaction tank. The method for treating organic matter-containing water according to claims 1 to 3.
A method for treating organic matter-containing water, which comprises replacing a part of the storage carrier with a part of the carrier in the reaction tank when the treatment of the reaction tank is stable. The method for treating organic matter-containing water according to claims 1 to 4.
A method for treating organic matter-containing water, wherein the reaction vessel has a stirring device for stirring the carrier. The method for treating organic matter-containing water according to claims 1 to 5.
A method for treating organic substance-containing water, wherein the carrier is a gel-like carrier. It is a treatment device for organic matter-containing water that biologically treats organic matter-containing water in a fluidized bed type reaction tank under anaerobic conditions.
A reaction tank for biological treatment by passing water containing organic matter while flowing a carrier to which anaerobic microorganisms including methane-fermenting bacteria form a biofilm.
A storage tank separate from the reaction tank for storing the carrier to which the anaerobic microorganisms are attached in the form of a biofilm,
A control unit that controls the addition of the storage carrier in the storage tank to the reaction tank when the treatment is lowered so that the organic acid concentration of the treated water in the reaction tank becomes a predetermined value or more.
A device for treating organic matter-containing water. The organic substance-containing water treatment apparatus according to claim 7.
A device for treating organic matter-containing water, wherein the storage carrier is added at the outlet side of an inflow pump for flowing the organic matter-containing water into the reaction vessel. The organic substance-containing water treatment apparatus according to claim 7.
A device for treating organic matter-containing water, wherein the storage tank is installed above the water surface of the reaction tank, and the storage carrier is naturally allowed to flow down and added to the reaction tank. The organic substance-containing water treatment apparatus according to claims 7 to 9.
The control unit is a device for treating organic matter-containing water, which controls so as to replace a part of the stored carrier with a part of the carrier in the reaction tank when the treatment of the reaction tank is stable. The organic substance-containing water treatment apparatus according to claim 7 to 10.
A device for treating organic matter-containing water, wherein the reaction vessel has a stirrer for stirring the carrier. The organic substance-containing water treatment apparatus according to claims 7 to 11.
A device for treating organic substance-containing water, wherein the carrier is a gel-like carrier.

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