JP2011092811A - Waste water treatment apparatus and waste water treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste water treatment apparatus which treats persistent chemical oxygen demand (COD) and biochemical oxygen demand (BOD) at a high load. <P>SOLUTION: The waste water treatment apparatus includes: a dispersed bacteria tank 1 to which a solution containing an organic matter is introduced and dispersed bacteria for decomposing the organic matter are charged; and a fluidized bed-type bioreactor tank 2 to which the solution treated in the dispersed bacteria tank 1 is introduced, a plurality of particulate carriers to which microorganisms for decomposing remaining organic matter is attached and a predatory organism of preying upon the dispersed bacteria are charged. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to environmental technology, and relates to a wastewater treatment apparatus and a wastewater treatment method.

  Conventionally, the activated sludge method has been widely used as a wastewater treatment method (see, for example, Patent Documents 1 and 2). However, the activated sludge method alone cannot treat wastewater containing a component that is hardly decomposable and increases the chemical oxygen demand (COD: Chemical Oxygen Demand) (hereinafter referred to as “the hardly decomposable COD component”). . Therefore, after decomposing difficult-to-decompose COD components by ozone oxidation, hydrogen peroxide addition, and ultraviolet (UV) irradiation in advance, the method of treating the wastewater by the activated sludge method, or treating the wastewater by the activated sludge method, A method of removing a hardly decomposable COD component from a treatment liquid by an activated carbon adsorption method is employed. However, these methods tend to increase initial costs and running costs.

  Moreover, there exists a fluidized bed bioreactor method as a method of removing a hardly decomposable COD component. In the fluidized bed bioreactor method, a fluidized bed bioreactor tank into which activated carbon as a microorganism carrier is charged and a circulating aeration tank are used. The fluidized bed bioreactor tank generates an upward flow in the introduced wastewater and floats activated carbon in the wastewater. The circulating aeration tank aerates the circulating water so that the dissolved oxygen is close to the saturated concentration. Circulating water containing oxygen at a high concentration is mixed with waste water and transferred to a fluidized bed bioreactor tank. Thereby, oxygen is supplied into the fluidized bed bioreactor tank.

  The circulating water is supplied to the fluidized bed bioreactor tank at a low flow rate such that the activated carbon does not leak from the fluidized bed bioreactor tank. Therefore, unlike the activated sludge method, the fluidized bed bioreactor tank has a very mild environment in a laminar flow state. Therefore, since a wide variety of bacteria and protozoa can be present on the activated carbon surface, it is possible to decompose the hardly decomposable COD component that is difficult to process by the activated sludge method.

Japanese Patent Publication No. 56-48235 Japanese Patent No. 3035569

  However, even though the fluidized bed bioreactor tank can decompose the hardly-decomposable COD component, there is a problem with the high-load COD or high-load BOD (Biochemical Oxygen Demand) treatment. Therefore, an object of the present invention is to provide a wastewater treatment apparatus and a wastewater treatment method capable of treating chemical oxygen demand (COD) and biochemical oxygen demand (BOD) with high load.

  In the aspect of the present invention, a dispersion fungus tank into which a solution containing an organic substance is introduced and a dispersed bacterium that decomposes the organic substance is introduced, and a microorganism that decomposes the remaining organic substance into which the solution treated in the dispersion bacteria tank is introduced The gist of the present invention is a wastewater treatment apparatus comprising a plurality of adhering particulate carriers and a fluidized bed bioreactor tank into which predatory organisms that prey on dispersal bacteria are introduced.

  Another aspect of the present invention includes a step of introducing a solution containing an organic substance into a dispersion fungus tank, a step of decomposing the organic substance by the dispersal bacteria in the dispersion fungus tank, and a solution treated in the dispersion fungus tank in a fluidized bed. Introducing into the bioreactor tank, decomposing organic matter remaining in the solution with microorganisms adhering to a plurality of particulate carriers in the fluidized bed bioreactor tank, and fluidized bed bioreactor tank And a step of causing the predatory organisms to prey on the dispersal bacteria in the solution.

  According to the present invention, it is possible to provide a wastewater treatment apparatus and a wastewater treatment method capable of treating a hardly decomposable chemical oxygen demand (COD) and a biochemical oxygen demand (BOD) with a high load.

It is a schematic diagram of the waste water treatment apparatus which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the waste water treatment apparatus which concerns on the comparative example of the 1st Embodiment of this invention. It is a schematic diagram of the waste water treatment apparatus which concerns on the modification of the 1st Embodiment of this invention. It is a schematic diagram of the waste water treatment apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the waste water treatment apparatus which concerns on the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the waste water treatment apparatus according to the first embodiment includes a dispersion fungus tank 1 into which a solution containing organic matter is introduced and dispersed bacteria (non-aggregating bacteria) that decompose the organic matter are introduced. The fluidized bed biotechnology, in which the solution treated in the dispersal bacteria tank 1 is introduced, and the number of particulate carriers to which microorganisms that decompose the remaining organic matter are attached, and predatory organisms that prey on the dispersal bacteria are introduced. Reactor tank 2.

  A solution containing an organic substance is supplied to the dispersal bacteria tank 1 through a pipe 11. Examples of the solution containing an organic substance include waste water containing a mixture of easily decomposable organic substances and hardly decomposable organic substances discharged from chemical factories, electronic machine component factories, building material factories, paint factories, and the like. Here, the easily degradable organic substance means an organic substance that can be easily decomposed by dispersal bacteria and can increase the biochemical oxygen demand (BOD) of the solution. The easily decomposable organic substance is also referred to as a BOD component. In addition, the hardly decomposable organic substance means an organic substance that is difficult to be decomposed by the dispersal bacteria and can increase the chemical oxygen demand (COD) of the solution. The hardly decomposable organic substance is also referred to as a hardly decomposable COD component. The drainage may be colored.

  As the dispersal bacteria introduced into the dispersal bacteria tank 1, the genus Alcaligenes, the genus Acinetobacter, and the like can be used. In addition, it is not necessary to introduce | transduce the isolated dispersal bacteria into the dispersal bacteria tank 1, You may throw in disperse bacteria by throwing in activated sludge etc. The dispersal bacteria tank 1 retains a solution containing an organic substance for 2 to 5 hours. While the solution containing the organic matter is retained in the dispersion bacteria tank 1 for 2 to 5 hours, the dispersion bacteria degrade, for example, about 70% of the readily degradable organic matter in the solution. Therefore, the BOD of the solution is lowered in the dispersion bacterium tank 1. In addition, it is possible to suppress the growth of the protozoa that prey on the dispersal bacteria in the disperse bacteria tank 1 by setting the time for the solution containing the organic matter in the disperse bacteria tank 1 to be 2 to 5 hours. It becomes.

  An oxygen supply blower 21 that supplies oxygen to the solution staying in the dispersed bacteria tank 1 is connected to the dispersed bacteria tank 1. Preferably, by supplying an oxygen supply blower 21 to the dispersed bacteria tank 1 through a rubber membrane diffuser tube, an OHR diffuser tube, or the like, fine bubble oxygen can be supplied to the solution staying in the dispersed bacteria tank 1. It becomes possible, and it becomes possible to raise the consumption efficiency of the dissolved oxygen by a dispersal microbe.

  The solution treated in the dispersed bacteria tank 1 includes a pipe 12 connected to the dispersed bacteria tank 1, a pipe 13 connected to the pipe 12, a suction pump 22 connected to the pipe 13, and a pipe connected to the suction pump 22. 14 is injected into the fluidized bed bioreactor tank 2 from the bottom of the fluidized bed bioreactor tank 2. The solution is stored in the fluidized bed bioreactor tank 2 by injecting the solution from the bottom of the fluidized bed bioreactor tank 2. Furthermore, a flow directed upward from the bottom of the fluidized bed bioreactor tank 2 in the direction opposite to the direction of gravity is formed in the solution stored in the fluidized bed bioreactor tank 2. A plurality of particulate carriers are dispersed in the solution by the formed flow, and the particle dispersion layer 30 is formed.

  The solution treated in the dispersed bacteria tank 1 and injected into the fluidized bed bioreactor tank 2 contains dispersed bacteria and a hardly degradable COD component that was not degraded by the dispersed bacteria. The dispersal bacteria are preyed on by predatory organisms such as protozoa (Firodina, Voltisella, Aspidisca, etc.) and metazoans (Nematoda, earthworms such as Aeolosoma), etc., which are put into the fluidized bed bioreactor tank 2. Since the amount of excess sludge generated is reduced due to food chains by predatory organisms, clear treated water is obtained in the fluidized bed bioreactor tank. Further, the hardly decomposable COD component adheres to a plurality of particulate carriers dispersed in the solution in the fluidized bed bioreactor tank 2. Activated carbon can be used for each of the plurality of particulate carriers. The persistent COD component attached to the plurality of particulate activated carbons includes bacteria such as Pseudomonas, Bacillus, and Zoogloea attached to the plurality of particulate activated carbons, and It is gradually biodegraded by microorganisms such as protozoa. Therefore, in the fluidized bed bioreactor tank 2, the chemical oxygen demand (COD: Chemical Oxygen Demand) of the solution decreases.

  The speed of the flow formed in the solution inside the fluidized bed bioreactor tank 2 is 5 to 40 m / hour. When the flow speed is slower than 5 m / hour, the dispersion of the plurality of particulate activated carbons becomes insufficient, and the plurality of particulate activated carbons may aggregate. In addition, when the flow speed is faster than 40 m / hour, a plurality of particulate activated carbons may be discharged from the fluidized bed bioreactor tank 2. By setting the flow speed to 5 to 40 m / hour, the plurality of particulate activated carbons are 1.2 to 1.5 times from the bottom of the fluidized bed bioreactor tank 2 compared to the case where there is no flow. It is suspended and dispersed to a certain height.

  The particle size of each of the plurality of particulate activated carbons is preferably 0.3 to 1.0 mm. When the particle size of the activated carbon is smaller than 0.3 mm, the total surface area of the plurality of particulate activated carbons is increased, so that a large number of microorganisms can be attached to the surface of the plurality of particulate activated carbons. However, when the amount of microorganisms increases, it may be necessary to increase the supply amount of oxygen consumed by the microorganisms. If the flow rate of the solution in the fluidized bed bioreactor tank 2 is increased in order to increase the supply amount of oxygen, a plurality of particulate activated carbons are discharged from the fluidized bed bioreactor tank 2, which is not preferable. .

  In addition, when the particle size of the activated carbon is larger than 1.0 mm, the total surface area of the plurality of particulate activated carbons decreases, so that the number of microorganisms attached to the surfaces of the plurality of particulate activated carbons also tends to decrease. Moreover, when the number of microorganisms decreases, the supply amount of oxygen consumed by the microorganisms also decreases. However, if the activated carbon particle size is larger than 1.0 mm, the mass of each activated carbon increases, so the fluidized bed bioreactor tank It may be necessary to increase the flow rate of the solution inside the two. Therefore, the energy consumption of the suction pump 22 is unnecessarily increased, which is not preferable. In addition, the particulate activated carbon does not need to be spherical and may be deformed.

  Among the solutions contained in the fluidized bed bioreactor tank 2, the supernatant liquid in which the plurality of particulate activated carbons are not dispersed is passed through the pipe 15 to the aeration tank 3 as an oxygen supply device. In the aeration tank 3, air is blown into the solution from the oxygen supply blower 23, and oxygen is supplied into the solution. The solution that is in a substantially saturated oxygen concentration state in the aeration tank 3 is again injected into the fluidized bed bioreactor tank 2 through the pipe 13, the suction pump 22, and the pipe 14 connected to the aeration tank 3. Therefore, the solution supplied with oxygen circulates through the fluidized bed bioreactor tank 2 and the aeration tank 3. Further, a part of the solution is discharged from the aeration tank 3 to the river or the like as a processed solution through the pipe 16.

  Here, as shown in FIG. 2, when no dispersal bacteria tank is installed upstream of the fluidized bed bioreactor tank 2, a solution having a high BOD as well as COD is directly injected into the fluidized bed bioreactor tank 2. The In this case, the oxygen demand of the solution introduced into the fluidized bed bioreactor tank 2 becomes extremely high compared to the case where a dispersed bacteria tank is installed. For this reason, microorganisms attached to the activated carbon at the bottom of the fluidized bed bioreactor tank 2 may grow rapidly, and agglomerates of soccer ball-sized activated carbon may be generated. Further, when activated carbon aggregates are generated, the uniformity of the upward flow of the solution formed in the fluidized bed bioreactor tank 2 is hindered to cause a drift, and the uniform dispersion of the activated carbon can be prevented. Furthermore, the interface between the particle-dispersed layer 30 and the supernatant rises, and the activated carbon may be discharged from the fluidized bed bioreactor tank 2.

  When a solution having a high BOD is injected, the dissolved oxygen in the solution in the fluidized bed bioreactor tank 2 becomes insufficient. In particular, in the vicinity of the bottom of the fluidized bed bioreactor tank 2, the dissolved oxygen in the solution becomes significantly insufficient. Therefore, it is necessary to increase the supply speed of the solution from the aeration tank 3 by the suction pump 22, and thus the power consumption of the suction pump 22 may increase.

  In contrast, in the wastewater treatment apparatus according to the first embodiment shown in FIG. 1, most of the readily decomposable organic matter is decomposed in the dispersed bacteria tank 1 installed upstream of the fluidized bed bioreactor tank 2. Therefore, since the BOD of the solution introduced into the fluidized bed bioreactor tank 2 is low, problems such as oxygen shortage, generation of filamentous fungi, and activated carbon aggregation in the fluidized bed bioreactor tank 2 are less likely to occur. Therefore, even when the COD and BOD of the solution before being introduced into the dispersal bacteria tank 1 are high, a stable operation can be performed over a long period. Further, since the flow rate of the solution formed in the fluidized bed bioreactor tank 2 can be reduced within a range where the activated carbon does not aggregate, the power consumption of the suction pump 22 can be reduced. It becomes.

(Modification of the first embodiment)
In the wastewater treatment apparatus according to the first embodiment shown in FIG. 1, the solution treated in the dispersed bacteria tank 1 is supplied to the fluidized bed bioreactor tank 2. On the other hand, as shown in FIG. 3, the solution treated in the dispersion bacterium tank 1 may be supplied to the aeration tank 3. The waste water treatment apparatus shown in FIG. 3 can also achieve the same effect as the waste water treatment apparatus shown in FIG.

(Second Embodiment)
As shown in FIG. 4, the wastewater treatment apparatus according to the second embodiment further includes a bulking inhibitor supply device 40 that supplies a bulking inhibitor that prevents bulking due to the generation of filamentous fungi to the dispersed bacteria tank 1. When the ratio of the BOD component, the nitrogen component, and the phosphorus component in the solution in the dispersion fungus tank 1 is maintained at 100: 5: 1, filamentous fungi are unlikely to be generated. However, since the concentration of the BOD component in the solution introduced from the factory or the like into the dispersal cell tank 1 changes sequentially, filamentous fungi may be generated in the disperse cell tank 1 due to loss of nutrient balance or the like.

  On the other hand, it is possible to suppress the occurrence of bulking in the dispersed bacteria tank 1 by supplying the dispersed bacteria tank 1 with a bulking inhibitor having a filamentous fungus lysing action from the bulking inhibitor supply apparatus 40. As a commercially available bulking inhibitor, “Bulhibitor” KEL225 and KEX250 series manufactured by Nippon Steel Environmental Engineering Co., Ltd. can be used. The amount of the bulking inhibitor to be introduced into the dispersed bacteria tank 1 is, for example, about 1 to 5 ppm with respect to the amount of the solution in the dispersed bacteria tank 1.

(Third embodiment)
In the fluidized bed bioreactor tank 2 shown in FIG. 4, ammonia nitrogen in the solution is nitrified by nitrifying bacteria which are aerobic bacteria including ammonia oxidizing bacteria such as nitrosomonas and nitrite oxidizing bacteria such as nitrobacter. And become nitrate nitrogen. Furthermore, nitrate nitrogen is denitrified in an anoxic region inside the fungus layer formed by denitrifying bacteria such as facultative anaerobes attached to the activated carbon, and becomes nitrogen gas or the like. However, when the nitrogen component of the solution introduced into the dispersed bacteria tank 1 is large, the nitrogen component may remain in the fluidized bed bioreactor tank 2 and the total nitrogen (TN) concentration may not decrease.

On the other hand, the waste water treatment apparatus according to the third embodiment further includes a denitrification tank 4 for removing nitrogen from the solution introduced into the fluidized bed bioreactor tank 2 as shown in FIG. The denitrification tank 4 is loaded with a carrier that holds denitrifying bacteria. As a denitrifying bacterium, a facultative anaerobic bacterium generally present in a large amount in sludge can be used, and examples thereof include the genus Pseudomonas. Denitrifying bacteria use the oxygen component of NO ₂ and NO ₃ as an oxygen respiration source to gasify N ₂ . Also, oxygen is combined with hydrogen and released as H ₂ O. As the carrier for holding the denitrifying bacteria, a fixed carrier and a fluid carrier can be used. For example, an inexpensive sponge carrier of about 40% is charged with respect to the volume of the denitrification tank 4. For example, SQA or KI manufactured by Achilles Corporation can be used as the sponge carrier.

  It is not preferable to introduce oxygen that suppresses the denitrification reaction into the denitrification tank 4. Further, an oxidation-reduction potential of −50 mV or less is necessary. Here, in the fluidized bed bioreactor tank 2, oxygen in the solution is mainly consumed in the lower particle dispersion layer 30. Therefore, the oxygen concentration in the solution decreases as it proceeds in the direction opposite to the direction of gravity. Therefore, in the denitrification tank 4, a solution having a low oxygen concentration above the fluidized bed bioreactor tank 2 is connected to a pipe 17 connected above the fluidized bed bioreactor tank 2 and a suction pump 24 connected to the pipe 17. , And the pipe 18 connected to the suction pump 24. The pipe 18 is connected to the bottom of the denitrification tank 4.

  In addition, a part of the solution before being treated in the dispersion bacteria tank 1 is introduced into the denitrification tank 4 through a pipe 19 that connects the pipe 11 and the suction pump 24. The solution before being processed in the dispersion bacterium 1 contains the BOD component without being decomposed. In the dispersed bacteria tank 1, the solution before being treated in the dispersed bacteria tank 1 is mixed with a solution having a low oxygen concentration coming from above the fluidized bed bioreactor tank 2. The BOD component contained in the solution before being treated in the dispersal bacteria tank 1 is used as a hydrogen donor for denitrifying bacteria. The amount of the solution introduced from the pipe 19 into the denitrification tank 4 is three times the amount of the BOD component with respect to the total nitrogen (TN) of the solution coming from above the fluidized bed bioreactor tank 2. It is set as follows. When this BOD component is insufficient, methanol or the like may be further injected into the denitrification tank 4 as a hydrogen donor for denitrifying bacteria.

  The solution injected into the denitrification tank 4 from the pipe 18 forms a flow in the direction opposite to the gravity direction from the bottom of the denitrification tank 4. The residence time of the solution in the denitrification tank 4 is about 4 hours. The denitrification tank 4 is provided with stirring means 61 such as a stirring plate connected to a stirring motor. The stirring means 61 gently stirs the solution in the denitrification tank 4 to degas the generated nitrogen bubbles and prevent the carrier from settling. The solution in the upper part of the denitrification tank 4 after the denitrification is completed is caused to flow into the aeration tank 3 through a pipe 51 that connects the denitrification tank 4 and the aeration tank 3.

  For example, when the total nitrogen (TN) concentration of the solution before being processed in the dispersion bacteria tank 1 is about 30 to 40 ppm, the solution discharged from the aeration tank 3 to the pipe 16 by providing the denitrification tank 4 It is possible to reduce the total nitrogen (TN) concentration to 7 to 10 ppm. The solution in the upper part of the denitrification tank 4 after the denitrification may be returned to the fluidized bed bioreactor tank 2.

  Next, the embodiment will be described more specifically with reference to examples and comparative examples. However, the embodiment is not limited to the following examples unless it exceeds the gist.

Example 1
In Example 1, the same apparatus as the waste water treatment apparatus shown in FIG. 4 was used. The volume of the dispersal cell tank 1 was 400 mL, and activated sludge containing the genus Alcaligenes and the genus Acinetobacter was charged. Moreover, as an organic substance containing solution introduce | transduced into the dispersion | distribution bacteria tank 1, BOD is 800 mg / L, COD (cr) is 1380 mg / L, and total organic carbon (TOC: Total Organic Carbon) is 300 mg / L. Paint drainage was used. The paint wastewater was introduced into the dispersal bacteria tank 1 at 2.5 L / day. In this case, the BOD volume load of the dispersal bacteria tank 1 is 5 kg-BOD / m ³ · day. The solution in the dispersal cell tank 1 was aerated at 4 L / min using a diffuser tube having a 2 mm hole in an L-shaped PVC pipe. In addition, a bulking inhibitor (Balhibitor “KEL225” manufactured by Nippon Steel Environmental Engineering Co., Ltd.) was supplied from the bulking inhibitor supply apparatus 40 so that the concentration in the dispersed bacteria tank 1 was 1 mg / L.

  The volume of the fluidized bed bioreactor tank 2 was 2.7 L, and the inner diameter was 3 cm. Further, in the fluidized bed bioreactor tank 2, the height of the liquid level of the solution was set to 3.8 m. Furthermore, 900 mL of activated carbon having an average particle diameter of 0.5 mm was charged into the fluidized bed bioreactor tank 2. Bacteria such as Pseudomonas, Bacillus, and Zoogloea, and microorganisms such as protozoa were attached to the activated carbon. The volume of the aeration tank 3 was 1 L. The solution is aerated in the aeration tank 3 at a rate of 0.15 L / min, the aerated solution is supplied to the bottom of the fluidized bed bioreactor tank 2 by the suction pump 22, and is directed upward into the fluidized bed bioreactor tank 2. A flow of solution was formed. The flow rate of the solution in the fluidized bed bioreactor tank 2 was 16 m / hour. The initial developed height of the activated carbon was 190 cm. The dissolved oxygen concentration at the bottom of the fluidized bed bioreactor tank 2 was 7 ppm, and the dissolved oxygen concentration at the top of the fluidized bed bioreactor tank 2 was 4 to 5 ppm.

  Under the above conditions, the solution was continuously processed for 4 months without stopping. As a result, the water quality of the treated solution discharged from the pipe 16 was good as shown in Table 1. Moreover, the deployment height of activated carbon after 4 months was 210 cm, which was only about 20 cm higher than 4 months ago. The total organic carbon (TOC) and total nitrogen (TN) were measured by centrifuging the solution (1500 rpm * 15 minutes) and applying the supernatant from which the cells had been removed to a TOC meter (manufactured by Shimadzu Corporation). The measuring method of total organic carbon (TOC) and total nitrogen (TN) is the same in the following examples.

(Comparative Example 1)
In Comparative Example 1, as shown in FIG. 2, a waste water treatment apparatus that does not have a dispersion fungus tank was used. The solution was treated under the same conditions as in Example 1 except that it did not have a dispersion fungus tank. The dissolved oxygen concentration at the bottom of the fluidized bed bioreactor tank 2 was 7 ppm as in Example 1, but the dissolved oxygen concentration at the top of the fluidized bed bioreactor tank 2 was 1 to 2 ppm. As a result of processing the solution, the amount of bacterial cells adhering to the activated carbon increased remarkably, the height of activated carbon increased to 3.8 m in about 3 months, and the activated carbon overflowed from the fluidized bed bioreactor tank 2. It was.

(Example 2)
In Example 1, when no bulking inhibitor was added to the dispersion fungus tank 1 shown in FIG. 4, a large amount of filamentous fungi was present in the dispersion funnel tank 1 after about 50 to 60 days had passed since the start of operation. At the same time, filamentous fungus grew in the fluidized bed bioreactor tank 2 and the developed height of activated carbon rapidly increased to 3 m. Therefore, when about 20 ppm of Balhibitor “KEX250” is added to the dispersal cell tank 1, the filamentous fungus disappears, and then the activated carbon deployment height in the fluidized bed bioreactor tank 2 is 2.1 m before the filamentous fungus is generated. Returned to height. Even when the operation was carried out without adding the bulking inhibitor, the development height did not increase due to the occurrence of filamentous fungi for about 50 days. Therefore, an anti-bulking agent is not essential depending on the operation period.

(Example 3)
In Example 3, the same apparatus as the waste water treatment apparatus shown in FIG. 5 was used. The same solution as in Example 1 was introduced into the dispersion bacteria tank 1 at 2.5 L / day. Moreover, the same apparatus as Example 1 was used on the same conditions for the dispersion | distribution bacteria tank 1, the fluidized bed bioreactor tank 2, and the aeration tank 3. FIG. In the denitrification tank 4 made of a vinyl chloride cylinder having a volume of 1 L and an inner diameter of 6.7 cm, the liquid level of the solution was set to 28 cm. In addition, 500 mL of 10 mm square urethane sponge (Achilles SQA) was added to the denitrification tank 4 as a carrier for denitrifying bacteria such as Pseudomonas.

  The denitrification tank 4 was introduced with 5.5 L / day of a solution having a low oxygen concentration from above the fluidized bed bioreactor tank 2. In addition, a part of the solution before being treated in the dispersion bacteria tank 1 was introduced into the denitrification tank 4 at 0.4 L / day. Furthermore, the residence time of the solution in the denitrification tank 4 was set to be 4 hours. The oxidation-reduction potential was −200 mV. Above the denitrification tank 4, a stirring means 61 provided with a rotating plate connected to an oriental motor was installed, and the solution in the denitrification tank 4 was stirred at 1 rotation / 10 seconds. The denitrified solution was returned to the aeration tank 3.

  The solution was continuously processed without stopping for about 4 months under the above conditions. As a result, the water quality of the treated solution discharged from the pipe 16 was good as shown in Table 3. Moreover, the deployment height of activated carbon after 4 months was 200 cm, which was only about 10 cm higher than 4 months ago.

Example 4
The same solution as in Example 1 was introduced into the dispersed bacteria tank 1 of the wastewater treatment apparatus shown in FIG. 5 at 3.8 L / day. In this case, the BOD volume load of the dispersal bacteria tank 1 was 7.5 kg-BOD / m ³ · day. Other than this, the solution was continuously processed without stopping for about 3 months under the same conditions as in Example 3. As a result, the water quality of the treated solution discharged from the pipe 16 was good as in Example 3 as shown in Table 3. Moreover, the deployment height of activated carbon after about 3 months was 220 cm, which was only about 30 cm higher than 3 months ago.

DESCRIPTION OF SYMBOLS 1 Dispersed bacteria tank 2 Fluidized bed type bioreactor tank 3 Aeration tank 4 Denitrification tank 11, 12, 13, 14, 15, 16, 17, 18, 19, 51 Pipe 21, 23 Oxygen supply blower 22, 24 Suction pump 30 Particles Dispersion layer 40 Bulking inhibitor supply device 61 Stirring means

Claims (13)

A dispersion fungus tank into which a solution containing an organic matter is introduced and into which the dispersal bacteria that decompose the organic matter are introduced;
A fluidized bed type in which a solution treated in the dispersal bacteria tank is introduced, and a plurality of particulate carriers to which microorganisms that decompose the remaining organic matter are attached, and predatory organisms that prey on the dispersal bacteria are input. A bioreactor tank;
A wastewater treatment device comprising:   The wastewater treatment apparatus according to claim 1, further comprising a bulking inhibitor supply device that supplies a bulking inhibitor to the dispersed bacteria tank.   The wastewater treatment apparatus according to any one of claims 1 to 3, further comprising a denitrification tank that removes nitrogen from the solution introduced into the fluidized bed bioreactor tank. In the fluidized bed bioreactor tank, the oxygen concentration in the solution decreases in the direction opposite to the direction of gravity,
The wastewater treatment apparatus according to claim 4, wherein the solution having a low oxygen concentration is introduced into the denitrification tank from above the fluidized bed bioreactor tank. Denitrifying bacteria are introduced into the denitrification tank,
The wastewater treatment apparatus according to claim 4 or 5, wherein a part of the solution before being treated in the dispersion bacteria tank is introduced into the denitrification tank as a carbon source of the denitrification bacteria.   The wastewater treatment apparatus according to any one of claims 4 to 6, further comprising a stirring unit that is provided in the denitrification tank and stirs the solution.   The wastewater treatment apparatus according to any one of claims 1 to 7, further comprising an oxygen supply apparatus that supplies oxygen to the solution introduced into the fluidized bed bioreactor tank.   The solution supplied with oxygen by the oxygen supply device is injected into the fluidized bed bioreactor tank from the bottom of the fluidized bed bioreactor tank and stored in the fluidized bed bioreactor tank. The waste water treatment apparatus according to claim 8, wherein a flow in a direction opposite to the direction of gravity is formed.   The waste water treatment apparatus of any one of Claims 1 thru | or 9 further equipped with the oxygen supply blower which supplies oxygen to the said solution stagnating in the said dispersion | distribution bacteria tank.   The wastewater treatment apparatus according to any one of claims 1 to 10, wherein each of the plurality of carriers is activated carbon.   The waste water treatment apparatus according to claim 11, wherein the activated carbon has an average particle size of 0.3 to 1 mm. Introducing a solution containing organic matter into the dispersal cell;
Decomposing the organic matter by the dispersal bacteria in the dispersal bacteria tank;
Introducing the solution treated in the dispersal bacteria tank into a fluidized bed bioreactor tank;
Decomposing the organic matter remaining in the solution with microorganisms attached to a plurality of particulate carriers in the fluidized bed bioreactor tank;
Feeding predatory organisms in the fluidized bed bioreactor tank with the dispersal bacteria in the solution;
Including wastewater treatment methods.   The wastewater treatment method according to claim 13, wherein in the step of decomposing the organic matter by the dispersed bacteria in the dispersed bacteria tank, the residence time of the solution in the dispersed bacteria tank is 2 to 5 hours.

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