JP2004314062A - Method and apparatus for treating waste water containing organic matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for efficiently and substantially decomposing organic matters in waste water. <P>SOLUTION: The apparatus for treating the waste water containing the organic matters comprises an oxygen dissolving device for dissolving oxygen in the waste water, after a primary treatment wherein hardly decomposable organic matters in the waste water are treated through a flocculation treatment and/or an electrolysis treatment, and a fluidized bed bioreactor for treating the waste water almost saturated with the oxygen and supplied by the oxygen dissolving device. The waste water containing the organic matters is primarily treated through a flocculation treatment device and/or an electrolysis treatment device. The oxygen is dissolved in the primarily treated waste water almost up to saturation by the oxygen dissolving device and subsequently the waste water is supplied to the fluidized bed bioreactor for the biological treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus and a method for treating organic-containing wastewater.

  Conventionally, wastewater containing a large amount of organic substances such as industrial wastewater such as paint wastewater discharged from a coating plant and agricultural wastewater is subjected to physical treatment such as coagulation separation (floating or sedimentation) treatment or ultrafiltration, and then activated sludge method. In general, biological treatment is performed under aerobic conditions (for example, see Patent Documents 1 and 2). However, in the ordinary activated sludge method, there is a limit to the ability of microorganisms to decompose organic substances, and in this method, organic substances that are difficult to decompose, such as water-soluble organic substances containing nitrogen, remain in the treated water as it is or even if it can be treated. There were problems such as the necessity of processing for a very long time.

  On the other hand, a large number of methods using not only biological treatment but also physical and chemical treatment methods such as ozone decomposition method, Fenton method, and UV irradiation method have been proposed for treating wastewater containing such a large amount of hardly decomposable substances. Was. For example, Patent Document 3 discloses a treatment method of irradiating ultraviolet light and / or visible light in the presence of a photooxidation catalyst to oxidatively decompose wastewater containing organic substances. However, these methods often make it difficult to decompose contaminants sufficiently, and even if they can be decomposed, it often takes a lot of time and cost to treat them. Taking paint wastewater as an example, the wastewater contains various pigments, dyes, organic resins, cross-linking agents, organic solvents, surfactants, oils, and other organic components. It varies depending on the type of plant, the factory that is the source, or the time of day when it occurs, and is not constant. Furthermore, these components are characterized by a large difference in solubility in water, physical / chemical degradability, biodegradability, etc., and are characteristic of the wastewater. Electrolytic treatment, coagulation treatment, ozone decomposition method, Fenton method, UV Organic substances that have not been sufficiently decomposed by physical or chemical treatment methods such as irradiation methods or ordinary methods such as activated sludge methods remain in treated water, and are often not effective as treatment methods. .

An object of the present invention is to provide a treatment apparatus and a treatment method for organic-containing wastewater, which can efficiently and sufficiently decompose organic substances contained in the wastewater.
Furthermore, an object of the present invention is to provide an organic matter-containing wastewater treatment apparatus and method capable of efficiently and sufficiently decomposing organic substances contained in wastewater and decomposing organic substances containing nitrogen into nitrogen gas. To provide.
JP-A-6-55172 JP-A-2003-39078 JP-A-8-155308

  The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the organic-containing wastewater is first subjected to electrolytic treatment and / or primary treatment by coagulation treatment, and then dissolved in oxygen to dissolve oxygen to near saturation. Biological treatment using a wastewater treatment device equipped with a fluidized bed bioreactor for treating wastewater in which oxygen is dissolved to near saturation, supplied from the oxygen dissolving device, and It has been found that a hardly decomposable organic substance can be sufficiently decomposed, and the present invention has been completed.

  That is, the present invention provides an oxygen dissolving apparatus for dissolving oxygen after subjecting a hardly decomposable organic substance contained in wastewater to primary treatment by electrolytic treatment and / or coagulation treatment, and oxygen supplied from the oxygen dissolving apparatus. An organic matter-containing wastewater treatment device equipped with a fluidized bed bioreactor for treating wastewater that has been dissolved to near saturation, and a primary treatment wastewater obtained by first treating an organic matter-containing wastewater with an electrolytic treatment device and / or a coagulation treatment device. The present invention relates to a method for treating organic matter-containing wastewater, comprising dissolving oxygen to near saturation with an oxygen dissolving apparatus, and then supplying wastewater in which the oxygen is dissolved to near saturation to a fluidized-bed bioreactor for microbial treatment.

  Furthermore, the present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the organic matter-containing wastewater was first subjected to electrolytic treatment and / or primary treatment by coagulation treatment, and then oxygen was dissolved to near saturation. The biological wastewater is treated by using a wastewater treatment device having an oxygen dissolving device and a fluidized bed bioreactor for treating wastewater that is supplied from the oxygen dissolving device and dissolves oxygen to near a saturated state. Found that it is possible to sufficiently decompose hardly decomposable organic substances in it, and furthermore, it is possible to sufficiently decompose nitrate nitrogen by installing a denitrification device separately and circulating wastewater with an oxygen dissolving device This led to the completion of the present invention.

  That is, the present invention provides a primary treatment apparatus for treating organic matter-containing wastewater in a primary treatment, an oxygen dissolving apparatus for dissolving oxygen in the primary treatment wastewater to near a saturated state, and dissolving oxygen supplied from the oxygen dissolving apparatus to near a saturated state. Fluidized-bed bioreactor for treating wastewater treated, and a denitrification device, a mechanism for supplying wastewater from the oxygen dissolving device to the fluidized-bed bioreactor and returning wastewater treated by the bioreactor to the oxygen dissolving device An organic matter-containing wastewater treatment device having a mechanism for supplying wastewater in the oxygen dissolution apparatus to a denitrification apparatus and returning the denitrified wastewater to the oxygen dissolution apparatus; and treating the wastewater in the oxygen dissolution apparatus with a fluidized bed. The present invention relates to a method for treating organic matter-containing wastewater, wherein microorganism treatment and denitrification treatment are performed by circulating both inside a bioreactor and a denitrification apparatus.

In the present invention, the organic matter-containing wastewater is industrial wastewater, agricultural wastewater, domestic wastewater, or the like discharged from factories or business establishments, and particularly includes paint wastewater. The paint wastewater includes, for example, paint lines for automobiles and various industrial products, paint booth water in a sheet metal factory, wastewater containing paint components from a paint factory, wash water in various factories, and the like. For example, as an example of the drainage of an automobile coating line, a sediment of 1 to 100 g / liter, a COD _{Mn of} 1,000 to 10,000 mg / liter, a TOC of 1,000 to 15,000 mg / liter, and a BOD of 1,000 to 5 2,000 mg / L, TN 100 to 600 mg / L, and organic solvent 1 to 10,000 mg / L. Here, COD _Mn means chemical oxygen demand, TOC means total organic carbon content, BOD means biochemical oxygen demand, and TN means total nitrogen content.

  Since the organic matter-containing wastewater contains a large amount of solids such as a resin, a pigment, and a curing agent, in the present invention, the wastewater is first subjected to a primary treatment for removing solids and the like. Examples of the primary treatment include addition of a coagulant, electrolytic treatment, and the like, whereby coagulation, floating or settling can be separated and removed.

  As the coagulant, for example, inorganic coagulants represented by aluminum sulfate, polyaluminum chloride, ferric chloride, etc., low molecular coagulants such as surfactants, anionic, weak anionic, nonionic or cationic high coagulants Molecular coagulants and the like can be mentioned, and these can be used alone or in combination of a plurality of types according to the type of wastewater.

In the electrolytic treatment, the electrodes are placed in wastewater and an electric current is applied.The fine bubbles of oxygen and hydrogen generated by the electrolysis of water are used to adsorb pigments and resins etc. Is collected on the drainage surface, and is effective even when combined with a treatment with a coagulant. In the electrolytic treatment, an electrolyte is usually charged and dissolved in supplied wastewater, a plurality of electrodes are arranged at appropriate intervals in the water tank, and electricity is supplied between the electrodes to perform electrolysis. Preferably, an aluminum electrode is used as the electrode, and sodium nitrate, sodium chloride or the like is used as the electrolyte.
Even after performing the treatment with the flocculant and the electrolytic treatment, the hydrophilic organic solvent and some resins, the curing agent, and the like remain in the wastewater.In the present invention, as the secondary treatment following the treatment, An oxygen dissolving apparatus for dissolving oxygen to near saturation, and a wastewater treatment apparatus including a fluidized bed bioreactor for treating wastewater supplied from the oxygen dissolution apparatus for dissolving oxygen to near saturation. To perform biological treatment.

  Alternatively, even after the treatment with the flocculant or the electrolytic treatment, the hydrophilic organic solvent, some resins, and the curing agent remain in the wastewater. As an oxygen dissolving device for dissolving oxygen to near the saturation state, a fluidized bed bioreactor for treating wastewater supplied from the oxygen dissolution device and dissolving oxygen to near the saturation state, and a denitrification device A mechanism for supplying wastewater from the oxygen dissolving apparatus to the fluidized bed bioreactor and returning wastewater treated by the bioreactor to the oxygen dissolving apparatus; and supplying wastewater in the oxygen dissolving apparatus to the denitrification apparatus to remove the wastewater. Biological treatment is performed using a circulation type wastewater treatment device having a mechanism for returning the wastewater subjected to the nitrification treatment to the oxygen dissolving device.

  The fluidized bed bioreactor is a bioreactor which is provided with a packed bed of a carrier on which microorganisms are adhered and grown, and makes the packed bed a fluidized bed by flowing wastewater in an upward flow. Compared to activated sludge equipment, which is more resistant to water quality fluctuations and climate change, stable treated water quality can be obtained, and the amount of excess sludge generated is extremely small, and there is no need for a sedimentation tank. Have. Further, since the device is compact, it can be installed in a small space.

  Microbial carriers used in the bioreactor include those having a large surface area per unit volume, such as hollow, irregular, or porous, or those that absorb water and swell, and have fluidity and easily flow out. Particles that do not have a specific gravity are preferred, and the carrier may have any shape such as a plate-like body, a fibrous body, a specially shaped body such as a cylinder, a sponge-like body, a grain / lumpy body, or a cubic body. A fine granular material that easily secures properties and surface area is preferable. As the carrier material, various kinds of conventionally known organic and inorganic carriers can be used, for example, granular activated carbon, crushed activated carbon, charcoal, zeolite, mica, sand grains; polyethylene resin, polypropylene resin, polyester resin, polyurethane resin Resin carriers such as silica gel; Porous ceramics such as silica gel; High molecular weight hydrogel such as polyethylene glycol gel, polyvinyl alcohol gel, polyurethane gel; Anthracite; These can be used alone or in combination of two or more. Among them, particularly preferred is activated carbon having a high ability to adsorb organic substances, a resin carrier mixed with activated carbon, silica gel or a polymer hydrogel. From the viewpoint of ease of handling and effective surface area, the particle size of the carrier is preferably from 0.3 to 15 mm, and more preferably from about 0.5 to 10 mm.

  The oxygen dissolving apparatus is for aerating treated water supplied to the bioreactor by a circulation pump, and for increasing dissolved oxygen consumed to decompose organic substances in a packed bed with a carrier in the bioreactor to a saturated oxygen concentration. It is a device that also serves to activate the flow of the packed bed in the bioreactor and at the same time peel off the excess part of the microbial membrane growing on the surface of the carrier to keep the thickness constant.

  The oxygen dissolving device is not particularly limited in shape and the like, but a device for generating fine bubbles as necessary for the purpose of efficiently supplying oxygen may be used, or pure oxygen or oxygen concentration other than ordinary air may be used. Can be passed through a mixed gas having a higher air pressure than air. As the fine bubble generating device, for example, "Dome Diffuser" (manufactured by KWI) can be mentioned.

  The circulation speed in the bioreactor is preferably higher than a certain level. The circulation speed (linear velocity) varies greatly depending on the amount, size and specific gravity of the carrier, the shape of the bioreactor, the oxygen supply capacity of the oxygen dissolving device, and the like. ) Is in the range of 1.5 to 30 m / h, preferably 5 to 20 m / h. When the circulation speed is less than 1.5 m / h, the quality of the treated water is deteriorated, and when the circulation speed is 30 m / h or more, a carrier outflow phenomenon may be observed.

  In the present invention, if nitrogen-containing organic matter is present in the final treated water after the treatment, a denitrification device can be further provided as necessary. This makes it possible to maintain water quality suitable for discharging directly into public waters such as rivers.

  The denitrification device is generally not particularly limited as long as it can convert organic nitrogen and ammonia in wastewater into nitrate, and can biologically convert it into nitrogen and release it into the atmosphere. Anaerobic biological treatment tanks can be used. The biological denitrification treatment includes, for example, a denitrifying bacteria activated sludge method in which sludge containing denitrifying bacteria is returned, and a method in which denitrifying bacteria are supported on a carrier and accumulated at high density in a denitrifying tank (fixed bed type, fluidized bed type). Etc.). If there is an effect of dissolved oxygen from the oxygen dissolving device, a separate tank for removing dissolved oxygen can be provided between the oxygen dissolving device and the denitrification device as necessary.

  In the present invention, if necessary, other wastewater treatment devices, such as an ozone decomposition treatment device, a UV treatment device, an adsorption treatment device using activated carbon, a general activated sludge treatment device, and membrane separation into a liquid containing activated sludge can be used. It is possible to appropriately use a membrane separation activated sludge treatment device provided with the device in combination.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a flowchart showing an embodiment of the present invention. In FIG. 1, reference numeral 3 denotes an electrolytic treatment tank, 6 denotes a fluidized bed bioreactor, 7 denotes an oxygen dissolving device, and 8 denotes a circulation pump.

  The organic matter-containing wastewater is first supplied by a pump 1 to an electrolytic treatment apparatus 3 provided with an electrode 2, where the solids that precipitate and float by the electrolytic treatment are removed.

  Next, the treated water subjected to the electrolytic treatment is supplied from the bottom to the fluidized bed bioreactor 6 filled with the microorganism carrier 5 by the pump 4, and is subjected to biological treatment while flowing upward in the bioreactor 6. The biologically treated liquid overflows from the upper part of the bioreactor 6 and is supplied to the oxygen dissolving device 7 from the upper part. An aeration device 9 for ejecting oxygen or air is installed at the bottom of the oxygen dissolving device 7. After the oxygen concentration of the treated water is increased to near saturation in the oxygen dissolving device 7, the oxygen is dissolved again by the circulation pump 8. Water is pumped into bioreactor 6.

  By repeating the above, the wastewater is continuously supplied while circulating the wastewater between the bioreactor 6 and the oxygen dissolving device 7, and the final treated water overflows and is discharged from the oxygen dissolving device 7. is there.

  FIG. 2 is a flowchart showing another embodiment of the present invention. In FIG. 2, 13 is an electrolytic treatment tank, 16 is a fluidized bed bioreactor, 17 is an oxygen dissolving device, 18 and 19 are circulation pumps, and 20 is a denitrification device.

  The organic matter-containing wastewater is first supplied by a pump 11 to an electrolytic treatment device 13 provided with an electrode 12, where the solids deposited and floated by the electrolytic treatment are removed.

  Next, the treated water subjected to the electrolytic treatment is supplied from the bottom to a fluidized bed type bioreactor 16 filled with a microorganism carrier 15 by a pump 14, and is subjected to biological treatment while flowing upward in the bioreactor 16. The biologically treated liquid overflows from the upper part of the bioreactor 16 and is supplied to the oxygen dissolving device 17 from the upper part. An aerator 21 for ejecting oxygen or air is installed at the bottom of the oxygen dissolving device 17. After the oxygen concentration of the treated water is raised to near saturation in the exhausted oxygen dissolving device 17, the circulation pump 18 again operates. The treated water is sent into the bioreactor 16 and circulated between the oxygen dissolving device 17 and the bioreactor 16. Separately from this, the treated water is sent from the oxygen dissolving device 17 to the denitrification device 20 by the circulation pump 19 and circulated between the oxygen dissolution device 17 and the denitrification device 20. In the denitrification device 20, nitrate nitrogen is reduced by anaerobic activated sludge and released into the atmosphere in the form of nitrogen gas.

  By repeating the above-mentioned circulation, wastewater is continuously supplied, and the final treated water overflows from the oxygen dissolving device 17 and is discharged.

Examples Hereinafter, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1
The coating wastewater of the automotive water-based paint was used as organic matter-containing wastewater. The organic matter-containing wastewater (A) had a COD _Mn of 8,500 mg / liter and a TOC of 9,200 mg / liter. This paint wastewater (A) was subjected to electrolytic treatment at 5 V for 60 minutes using an electrolytic treatment device equipped with an aluminum electrode to remove solids that had precipitated and floated. As a result, an almost transparent electrolytic treatment liquid (B) was obtained. The COD _Mn of this electrolytic treatment solution (B) was 5,250 mg / L and the TOC was 6,400 mg / L. A fluidized-bed bioreactor with an internal volume of 2.5 liters filled with 300 g of granular activated carbon having an average particle size of about 0.8 mm and an oxygen dissolving tank with an internal volume of 10 liters equipped with an aerator are connected by piping, and both are connected by a pump. The electrolytic treatment liquid (B) was treated using a biological treatment apparatus (see FIG. 1) that circulates the water to obtain final treated water.

The coagulant "Crystack B100" (Kurita Kogyo) and 1,500 mg / L of "Crystak B450" (Kurita Kogyo) are added to the organic matter-containing wastewater (A), and then left for one day. Then, when the aggregate was removed, an aggregation treatment liquid (D) was obtained. The COD _Mn of this aggregation treatment liquid (D) was 5,550 mg / liter, and the TOC was 6,900 mg / liter. The coagulation liquid (D) was subjected to biological treatment under the same conditions as in Example 1 to obtain final treated water.

  The treatment was performed in the same manner as in Example 1 except that 600 g of silica gel particles having an average particle diameter of about 2 mm were used as a carrier.

  The treatment was carried out in the same manner as in Example 1 except that 70 g of a hollow cylindrical polypropylene carrier containing powdered activated carbon having a diameter of about 4 mm and a height of about 5 mm was used as the carrier.

Comparative Example 1

  The treatment was performed in the same manner as in Example 1 except that the biological treatment was performed using an activated sludge apparatus having an aeration tank having an internal volume of about 1 liter.

Comparative Example 2

  In order to confirm the effect of adsorption by activated carbon, 300 g of the granular activated carbon used in Example 1 was added to 2.5 liters of the electrolytically treated solution (B), stirred, left for 2 days, and added to the final treated water. And

Comparative Example 3

  When the treatment was performed in the same manner as in Example 1 except that the electrolytic treatment was not performed, the stable operation could not be continued because the inside of the bioreactor was clogged with solids, and the test was stopped.

Table 1 below summarizes the COD _Mn and TOC of the final treated water obtained by the treatment of Example 1-4 and Comparative Example 1-3.

The coating wastewater of the automotive water-based paint was used as organic matter-containing wastewater. The organic matter-containing wastewater (E) had a COD _Mn of 8,500 mg / L, a TOC of 9,200 mg / L, and a TN of 350 mg / L. This paint wastewater (E) was subjected to an electrolytic treatment at 5 V for 60 minutes using an electrolytic treatment device equipped with an aluminum electrode to remove precipitated and floating solids. As a result, a substantially transparent electrolytic treatment liquid (F) was obtained. The electrolytic solution (F) had a COD _Mn of 5,250 mg / liter, a TOC of 6,400 mg / liter, and a TN of 320 mg / liter. A bioreactor with an internal volume of 2.5 liters containing 300 g of granular activated carbon having an average particle diameter of about 0.8 mm, and an oxygen dissolving tank with an internal volume of 10 liters equipped with an aeration device are connected by pipes, and circulated between the two by a pump. An electrolytic treatment solution (F) is further provided by using a biological treatment apparatus (see FIG. 2) in which a denitrification apparatus having an inner volume of 5 liters using activated sludge and an oxygen dissolving tank are connected by piping and circulated between the two by a pump. To obtain final treated water.

The coagulant "Crystak B100" (Kurita Kogyo) and 1,500 mg / L of "Crystak B450" (Kurita Kogyo) are added to the organic matter-containing wastewater (E), and then left for one day. Then, when the aggregate was removed, an aggregate treatment liquid (G) was obtained. The COD _Mn of this aggregation treatment liquid (G) was 5,550 mg / liter, TOC was 6,900 mg / liter, and TN was 330 mg / liter. The coagulation liquid (G) was subjected to biological treatment under the same conditions as in Example 5 to obtain final treated water.

  The treatment was carried out in the same manner as in Example 5, except that 600 g of silica gel particles having an average particle diameter of about 2 mm were used as a carrier.

  The treatment was carried out in the same manner as in Example 5 except that 70 g of a hollow cylindrical polypropylene carrier mixed with powdered activated carbon having a diameter of about 4 mm and a height of about 5 mm was used as the carrier.

Comparative Example 4

  The treatment was carried out in the same manner as in Example 5, except that the biological treatment was carried out by the activated sludge method using an aeration tank having an internal volume of about 1 liter.

Comparative Example 5

  In order to confirm the effect of adsorption by activated carbon, 300 g of the granular activated carbon used in Example 5 was added to 2.5 liters of the electrolytically treated solution (F), stirred, left for 2 days, and added to the final treated water. And

Comparative Example 6

  The treatment was carried out in the same manner as in Example 5 except that the electrolytic treatment was not carried out. As a result, the reactor was clogged with solids, so that stable operation could not be continued and the test was stopped.

Comparative Example 7

  The treatment was carried out in the same manner as in Example 5 except that a biological treatment apparatus only circulating between the bioreactor and the oxygen dissolving tank without using a denitrification apparatus was used.

Table 2 below summarizes the COD _Mn and TOC of the final treated water obtained by the treatments in Example 5-8 and Comparative Example 4-7.

  According to the method of the present invention, organic matter-containing wastewater such as industrial wastewater or agricultural wastewater such as paint wastewater can be efficiently and sufficiently treated.

  Further, according to the method of the present invention, wastewater containing organic matter such as industrial wastewater or agricultural wastewater such as paint wastewater can be efficiently and sufficiently treated, and not only organic matter but also nitrate nitrogen generated by decomposition of organic matter can be reduced. It can be sufficiently removed.

It is a drainage processing flowchart explaining a suitable embodiment of the present invention. It is a drainage processing flowchart explaining the other aspect of the suitable implementation of this invention.

Explanation of reference numerals

1, 4, 8 pumps
2 electrodes
Reference Signs List 3 electrolytic treatment device 5 carrier 6 fluidized bed bioreactor 7 oxygen dissolution device 9 aeration device 11, 14, 18, 19 pump
12 electrodes
Reference Signs List 13 electrolytic treatment device 15 carrier 16 fluidized bed bioreactor 17 oxygen dissolution device 20 denitrification device 21 aeration device

Claims (14)

  An electrolytic treatment device and / or a coagulation treatment device for primary treatment of organic matter-containing wastewater, an oxygen dissolution device for dissolving oxygen in a primary treatment wastewater to near a saturated state, and an oxygen dissolution device supplied from the oxygen dissolution unit near a saturated state An apparatus for treating organic-containing wastewater, comprising a fluidized-bed bioreactor having a microbial carrier for treating wastewater that has been dissolved to a maximum.   The treatment apparatus according to claim 1, wherein the carrier of the fluidized bed bioreactor is activated carbon, a resin carrier containing activated carbon, silica gel, or a polymer hydrogel.   The treatment apparatus according to claim 1, wherein the organic matter-containing wastewater is paint-containing wastewater.   The treatment device according to any one of claims 1 to 3, further comprising a denitrification device for denitrification of the wastewater.   The primary treatment wastewater obtained by first treating organic matter-containing wastewater with an electrolytic treatment device and / or a coagulation treatment device is used to dissolve oxygen to near saturation with an oxygen dissolving device. A method for treating organic matter-containing wastewater, wherein the wastewater is supplied to a bioreactor and treated with microorganisms.   The treatment method according to claim 5, wherein the wastewater subjected to the microorganism treatment is further subjected to a denitrification treatment by a denitrification device.   Primary treatment device for primary treatment of organic matter-containing wastewater, oxygen dissolution device for dissolving oxygen in the primary treatment wastewater to near saturation, and treatment of wastewater supplied from the oxygen dissolution device and dissolving oxygen to near saturation A fluidized bed bioreactor having a microbial carrier therein, and a denitrification device, supplying wastewater of the oxygen dissolving device to the fluidized bed bioreactor, and returning wastewater treated by the bioreactor to the oxygen dissolving device An organic matter-containing wastewater treatment device, comprising: a mechanism; and a mechanism for supplying wastewater in the oxygen dissolution device to a denitrification device and returning the denitrified wastewater to the oxygen dissolution device.   The treatment device according to claim 7, wherein the primary treatment device for the wastewater is an electrolytic treatment device and / or a coagulation treatment device.   9. The treatment apparatus according to claim 7, wherein the carrier of the fluidized bed bioreactor is activated carbon, a resin carrier containing activated carbon, silica gel, or a polymer hydrogel.   The treatment apparatus according to any one of claims 7 to 9, wherein the organic matter-containing wastewater is paint-containing wastewater. (1) primary treatment of organic matter-containing wastewater,
(2) a step of dissolving oxygen in the primary treatment wastewater to near saturation with an oxygen dissolving device;
(3) a step of supplying a wastewater in which oxygen is dissolved to near a saturated state to a fluidized bed bioreactor in which a microorganism carrier is present, and performing a microorganism treatment;
(4) a step of returning the wastewater obtained by the microorganism treatment to the oxygen dissolving apparatus, supplying the wastewater in the oxygen dissolving apparatus to the denitrification apparatus, and performing a denitrification treatment by the denitrification apparatus;
(5) returning the denitrified wastewater to the oxygen dissolving apparatus;
A wastewater treatment method comprising: performing a microorganism treatment and a denitrification treatment by circulating wastewater in an oxygen dissolving apparatus both in a fluidized bed bioreactor and in a denitrification apparatus. Processing method.   The treatment method according to claim 11, wherein the primary treatment of the wastewater is performed using an electrolytic treatment device and / or a coagulation treatment device.   The treatment method according to claim 11 or 12, wherein the carrier of the fluidized bed bioreactor is activated carbon, a resin carrier mixed with activated carbon, or silica gel.   The treatment method according to any one of claims 11 to 13, wherein the organic matter-containing wastewater is paint-containing wastewater.

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