JP2007326075A - Waste water treatment method and waste water treatment equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste water treatment method which can be implemented with simple equipment and at a low cost, also can directly control the concentration of microorganisms in a treatment tank, and is easy in adjustment and management of facilities in the waste water treatment method for removing nitrogen in waste water by the action of the microorganisms. <P>SOLUTION: The waste water treatment method comprises introducing water to be treated 90 which should be treated and micronano bulb-containing water into a water tank 22, carrying out nitrification by the action of aerobic microorganisms in the water tank 22, and then carrying out denitrification by the action of anaerobic microorganisms in the water tank 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wastewater treatment method and a wastewater treatment apparatus, and more particularly to a wastewater treatment method and a wastewater treatment apparatus for removing nitrogen in wastewater by the action of microorganisms.

  Conventionally, in order to remove nitrogen in wastewater by the action of microorganisms, there has been a problem that a large facility is required, and initial cost and running cost are high.

In addition, there is no method for controlling the microorganism concentration in the treatment tank by electrical control, and it is difficult to adjust and manage the equipment. Specifically, in order to increase the concentration of microorganisms in the treatment tank, it was necessary to add nutrients or increase the inflow load and wait for the propagation of microorganisms. Moreover, when trying to reduce the microbial concentration in a processing tank, there was no means other than removing the microbial sludge from the settling tank for precipitating the return sludge, which was inconvenient.
JP 2004-121962 A JP 2003-334548 A JP 2004-321959 A

  Accordingly, an object of the present invention is a wastewater treatment method for removing nitrogen in wastewater by the action of microorganisms, which can be carried out with simple equipment at low cost, and electrically controls the microorganism concentration in the treatment tank. It is an object to provide a wastewater treatment method that can be controlled by the control and can easily adjust and manage the equipment.

  Moreover, the subject of this invention is providing the waste water treatment suitable for implementing such a waste water treatment method.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-121962) discloses a method and apparatus for using nanobubbles, including a decrease in buoyancy of nanobubbles, an increase in surface area, an increase in surface activity, generation of a local high-pressure field, and electrostatic polarization. The thing utilizing the characteristics such as the surface active action and the bactericidal action by realizing is described. More specifically, by interlinking them, various objects can be washed with high functionality and low environmental load by the adsorption function of dirt components, the high-speed washing function of the object surface, and the sterilization function. It is described that purification can be performed.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-334548) discloses a method for generating nanobubbles, a step of decomposing and gasifying a part of the liquid in the liquid, a step of applying ultrasonic waves in the liquid, It describes what consists of a step of cracking and gasifying a part of the liquid and a step of applying ultrasonic waves.

  Further, in Patent Document 3 (Japanese Patent Laid-Open No. 2004-321959), as a waste liquid treatment apparatus using ozone microbubbles, ozone gas generated from an ozone generator and a lower part of a treatment tank are extracted from a microbubble generator. It is described that the waste liquid is supplied via a pressure pump. It also describes that the generated ozone microbubbles are vented into the waste liquid in the treatment tank through the opening of the gas blowing pipe.

  However, Patent Document 1 (Japanese Patent Laid-Open No. 2004-121962), Patent Document 2 (Japanese Patent Laid-Open No. 2003-334548), and Patent Document 3 (Japanese Patent Laid-Open No. 2004-321959) are all of the present invention. It does not disclose the subject matter.

  “Microbubbles” are defined as “bubbles having a diameter of 10 to several tens of μm when they are generated”. The microbubbles contract after generation and change to “micronano bubbles”.

  “Micro-nano bubbles” mean bubbles having a diameter of several hundred nm to 10 μm.

  “Nanobubble” means a bubble having a diameter of several hundred nm or less.

In order to solve the above problems, the wastewater treatment method of the present invention is:
Treated water to be treated and water containing micro-nano bubbles are introduced into one aquarium, nitrified by the action of aerobic microorganisms in the aquarium, and then denitrified by the action of anaerobic microorganisms in the aquarium It is characterized by.

  In the wastewater treatment method of the present invention, since nitrification and denitrification are performed in the same water tank (a nitrification denitrification tank described later), it can be performed with simple equipment and at low cost (particularly, low initial cost). Moreover, the microorganism concentration in the said water tank can be controlled by electrical control by adjusting the amount of the micro / nano bubbles in the micro / nano bubble-containing water. Specifically, increasing the amount of micro-nano bubbles increases the microbial concentration, and decreasing the amount of micro-nano bubbles decreases the microbial concentration. Therefore, the adjustment and management of the facilities become easy.

  In one embodiment of the waste water treatment method, the water containing micro-nano bubbles and microbial sludge are mixed and introduced into the water tank.

  Here, “microbial sludge” means sludge containing microorganisms.

  In the wastewater treatment method of this embodiment, since the micronanobubble-containing water and microbial sludge are first mixed, microorganisms activated by the micronanobubbles are introduced into the water tank.

  In the wastewater treatment method according to an embodiment, when the nitrification is performed, the contents of the water tank are aerated by an aeration unit.

  In the wastewater treatment method of this embodiment, when the nitrification is performed, if the contents of the water tank are aerated by the aeration unit, the aerobic microorganisms (particularly nitrifying bacteria) activated by the micro-nano bubbles cause ammonia in the treated water. Nitrogen is easily oxidized to nitrate nitrogen. Therefore, nitrification is reliably performed.

  In the wastewater treatment method of one embodiment, when the denitrification is performed, aeration by the aeration unit is stopped, and the contents of the water tank are agitated by the agitation unit.

  In the wastewater treatment method according to this embodiment, when the denitrification is performed, if aeration by the aeration unit is stopped, oxygen is not supplied into the water tank. If the residual oxygen in the water tank is consumed by microorganisms, the water tank becomes oxygen-free or low-oxygen. Then, the vagina of the water to be treated is performed by the anaerobic microorganisms (particularly the vagina bacteria) activated by the micro / nano bubbles. Further, when performing the denitrification, the contents of the water tank are agitated by the agitation unit, so that the devagination can be advanced efficiently.

  Further, in this wastewater treatment method, when the denitrification is performed, aeration by the aeration unit is stopped, so that energy saving and low running cost are achieved.

  In one embodiment of the wastewater treatment method, the nitrification and the denitrification in the water tank are repeated alternately and periodically.

  In the wastewater treatment method according to this embodiment, the nitrification and the denitrification in the water tank are alternately and periodically repeated, so that continuous treatment of wastewater can be performed.

In the wastewater treatment method of one embodiment,
The microbial sludge is obtained as return sludge water in a sedimentation tank provided downstream of the water tank, and the micronanobubble-containing water is added to the return sludge water so that the microorganism concentration in the water tank is within a predetermined range. Controlled and mixed.

  In the wastewater treatment method of this embodiment, the microorganism concentration in the water tank is controlled within a predetermined range. Therefore, nitrification and denitrification are surely performed in the nitrification denitrification tank.

The waste water treatment apparatus of this invention
A water tank into which treated water to be treated is introduced;
A mixture introduction part for mixing and introducing micro-nano bubble-containing water and microbial sludge into the water tank;
An aeration section for aeration of the contents of the aquarium,
A controller that operates the aeration unit so as to perform nitrification by the action of aerobic microorganisms in the aquarium, and then deactivates the aeration unit so as to perform denitrification by the action of anaerobic microorganisms in the aquarium. It is characterized by having.

  In the wastewater treatment apparatus of the present invention, the microorganisms introduced into the water tank by the mixture introduction part are in a state activated by the micro / nano bubbles. Here, when the control unit operates the aeration unit to aerate the contents of the water tank, the aerobic microorganisms (nitrifying bacteria) activated by the micro / nano bubbles cause ammonia nitrogen in the water to be treated to nitrate nitrogen. It is easily oxidized. Therefore, nitrification is reliably performed. Thereafter, when the control unit deactivates the aeration unit, oxygen is not supplied into the water tank. If the residual oxygen in the water tank is consumed by microorganisms, the water tank becomes oxygen-free or low-oxygen. Then, the vagina of the water to be treated is performed by the anaerobic microorganisms (particularly the vagina bacteria) activated by the micro / nano bubbles.

  In this wastewater treatment apparatus, nitrification and denitrification are performed in the same water tank (a nitrification denitrification tank, which will be described later), and therefore it can be performed with simple equipment and at low cost (particularly, low initial cost). Further, when the denitrification is performed, the control unit deactivates the aeration unit, thereby saving energy and reducing the running cost. Moreover, in this waste water treatment apparatus, the microorganism concentration in the water tank can be controlled by electrical control by adjusting the amount of micro-nano bubbles in the micro-nano bubble-containing water. Specifically, increasing the amount of micro-nano bubbles increases the microbial concentration, and decreasing the amount of micro-nano bubbles decreases the microbial concentration. Therefore, the adjustment and management of the facilities become easy.

In the wastewater treatment apparatus of one embodiment,
A stirring section for stirring the contents of the water tank,
The control unit operates the aeration unit so as to perform nitrification by the action of aerobic microorganisms in the water tank, and after deactivating the stirring unit, performs denitrification by the action of anaerobic microorganisms in the water tank. As described above, control is performed to deactivate the aeration unit and operate the agitation unit.

  In the waste water treatment apparatus of this embodiment, when performing the denitrification, the control unit operates the stirring unit to stir the contents of the water tank. Thereby, a vagina can be advanced efficiently.

In the wastewater treatment apparatus of one embodiment,
A stirring section for stirring the contents of the water tank,
The control unit operates the aeration unit and performs the nitrification with the agitation unit deactivated so as to perform continuous treatment of drainage, and deactivates the aeration unit and operates the agitation unit. It is characterized in that control is performed in which the period of denitrification is alternately and periodically repeated.

  In the wastewater treatment apparatus of this embodiment, the nitrification and the denitrification in the water tank are alternately and periodically repeated, so that the wastewater can be continuously treated.

In the wastewater treatment apparatus of one embodiment,
Provided with a denitrification tank provided downstream from the water tank,
Following the denitrification in the water tank, further denitrification is performed in the denitrification tank.

  In the waste water treatment apparatus of this embodiment, since the denitrification is further performed in the denitrification tank following the denitrification in the water tank, the denitrification of the water to be treated is reliably performed.

In the wastewater treatment apparatus of one embodiment,
An oxidation-reduction potentiometer for measuring the oxidation-reduction potential in the water tank;
And a hydrogen donor addition section for introducing a hydrogen donor into the water tank so that the redox potential in the water tank falls within a predetermined range based on the output of the oxidation-reduction potentiometer.

  In the wastewater treatment apparatus of this embodiment, the oxidation-reduction potential in the water tank is controlled within a predetermined range. Here, since nitrification is a kind of oxidation and denitrification is a kind of reduction, if the oxidation-reduction potential in the water tank is controlled within a predetermined range, nitrification and denitrification in the water tank are smooth. To be done. For example, if the oxidation state in the water tank is too strong when performing the nitrification, it takes a long time to bring the water tank into a reduced state in order to perform the denitrification. Moreover, since the hydrogen donor addition part introduces the hydrogen donor into the water tank, the denitrification of the water to be treated is reliably performed in the water tank.

In the wastewater treatment apparatus of one embodiment,
A microbial concentration meter for measuring the microbial concentration in the water tank is provided,
A microorganism concentration control unit is provided that controls the amount of the micro-nano bubbles introduced into the water tank so that the microorganism concentration in the water tank falls within a predetermined range based on the output of the microorganism concentration meter.

  In the wastewater treatment apparatus of this embodiment, the microorganism concentration in the water tank is controlled within a predetermined range. Therefore, nitrification and denitrification are reliably performed in the water tank.

In another aspect, the waste water treatment apparatus of the present invention is
Raw water tank for storing raw water as treated water to be treated;
A nitrification and denitrification tank for performing nitrification and primary denitrification on the water to be treated taken out from the raw water tank;
A denitrification tank that performs secondary denitrification on the water to be treated from the nitrification denitrification tank;
A re-aeration tank for aeration of the treated water from the denitrification tank;
In addition to sequentially providing a sedimentation tank that collects treated water from the re-aeration tank and separates it into supernatant water and return sludge water,
A micro / nano bubble generating tank for adjusting micro / nano bubble-containing water by generating micro / nano bubbles with a micro / nano bubble generator for the supernatant water taken out from the precipitation tank;
A mixture introduction unit for adjusting the mixture of the returned sludge water taken out from the settling tank and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank and introducing the mixture into the nitrification / denitrification tank,
The nitrification / denitrification tank is provided with an aeration section for aeration of the contents of the nitrification / denitrification tank, and a stirring section for stirring the contents of the nitrification / denitrification tank,
The aeration unit is operated so as to perform the nitrification by the action of aerobic microorganisms in the nitrification denitrification tank, and the first denitrification is performed in the nitrification denitrification tank, and the period during which the agitation unit is not operated. As described above, a control unit is provided that performs control so that the aeration unit is inoperative and the period in which the agitation unit is operated alternately and periodically.

  In the wastewater treatment apparatus of the present invention, the microorganisms introduced into the nitrification / denitrification tank by the mixture introduction unit are activated by the micro / nano bubbles. Here, when the control unit operates the aeration unit to aerate the contents of the nitrification denitrification tank, ammonia nitrogen in the water to be treated is nitrated by aerobic microorganisms (nitrification bacteria) activated by micro-nano bubbles. It is easily oxidized to nitrogen. Therefore, nitrification is reliably performed. Thereafter, when the control unit deactivates the aeration unit, oxygen is not supplied into the nitrification denitrification tank. When residual oxygen in the nitrification denitrification tank is consumed by microorganisms, the nitrification denitrification tank becomes anoxic or low oxygen. Then, the vagina of the water to be treated is performed by the anaerobic microorganisms (particularly the vagina bacteria) activated by the micro / nano bubbles. In addition, when performing the denitrification, the control unit operates the agitation unit to agitate the contents of the nitrification denitrification tank, so that devagination can proceed efficiently.

  In this waste water treatment apparatus, since nitrification and denitrification are performed in the same water tank (that is, nitrification denitrification tank), it can be performed with simple equipment and at low cost (particularly, low initial cost). Further, when the denitrification is performed, the control unit deactivates the aeration unit, thereby saving energy and reducing the running cost. Moreover, in this waste water treatment apparatus, the microorganism concentration in the water tank can be controlled by electrical control by adjusting the amount of micro-nano bubbles in the micro-nano bubble-containing water. Specifically, increasing the amount of micro-nano bubbles increases the microbial concentration, and decreasing the amount of micro-nano bubbles decreases the microbial concentration. Therefore, the adjustment and management of the facilities become easy.

  In addition, if raw water is introduced into the micro / nano bubble generation tank, the micro / nano bubble discharge port (hole) of the micro / nano bubble generator is generally small, so that suspended substances contained in the raw water clog the holes of the micro / nano bubble generator. There is a risk that. In contrast, in the wastewater treatment apparatus of the present invention, in the micro / nano bubble generation tank, the micro / nano bubble is contained in the supernatant water taken out from the settling tank by the micro / nano bubble generator to adjust the micro / nano bubble-containing water. Yes. In other words, the micro / nano bubble generator is not immersed in raw water. Therefore, suspended solids contained in the raw water do not clog the holes of the micro / nano bubble generator.

  The waste water treatment apparatus of one embodiment is characterized by comprising a micro / nano bubble generation aid addition unit for introducing a micro / nano bubble generation aid into the micro / nano bubble generation tank.

  In general, it is said that the supernatant water taken out from the sedimentation tank has a relatively good water quality and is unlikely to generate micro-nano bubbles. However, in the wastewater treatment apparatus of this embodiment, the micro / nano bubble generation aid is introduced into the micro / nano bubble generation tank by the micro / nano bubble generation aid addition unit. Therefore, the micro / nano bubbles can be generated well in the water to be treated in the micro / nano bubble generation tank.

  In one embodiment of the wastewater treatment apparatus, the mixture introduction unit introduces the returned sludge water taken out from the precipitation tank and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank, and mixes the mixture. A mixing tank to be adjusted is provided.

  In the wastewater treatment apparatus of this embodiment, the mixture introduction unit introduces the return sludge water taken out from the precipitation tank and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank into the mixing tank, and the mixing The above mixture is prepared by mixing in a tank. Therefore, since the returned sludge water and the micro-nano bubble-containing water are in direct contact, microorganisms are easily activated by the micro-nano bubbles. The mixture containing activated microorganisms is introduced from the mixing tank into the nitrification denitrification tank. Therefore, the microorganisms introduced into the nitrification denitrification tank are activated by micro-nano bubbles.

  Moreover, in this waste water treatment apparatus, since the returned sludge water passes through the mixing tank, the contents of the mixing tank can be collected, and the activated state of the microorganism can be observed with a microscope.

In the wastewater treatment apparatus of one embodiment,
The waste water treatment apparatus according to claim 13,
At least one of the nitrification denitrification tank, the denitrification tank, the re-aeration tank, and the precipitation tank contains a microbial carrier for propagating microorganisms.

  In the wastewater treatment apparatus of this embodiment, a microbial carrier for propagating microorganisms is accommodated in at least one of the nitrification denitrification tank, the denitrification tank, the re-aeration tank, and the precipitation tank. Therefore, microorganisms can be propagated at high concentrations on each microorganism carrier, and the efficiency of treatment with microorganisms can be increased. For example, in the above denitrification tank, denitrifying bacteria can be propagated at a high concentration on the microorganism carrier, so that the denitrification efficiency can be increased. In the precipitation tank, denitrifying bacteria can be propagated at a high concentration on the microorganism carrier, so that the denitrification efficiency can be further increased.

  In one embodiment of the waste water treatment apparatus, the microorganism carrier is a polyvinylidene chloride material having a string shape or a ring shape.

  In the wastewater treatment apparatus of this embodiment, the microbial carrier is, for example, a commercially available string-like or ring-like polyvinylidene chloride material. A string-like or ring-like polyvinylidene chloride material has a relatively large surface area and is suitable for propagating microorganisms. For example, if the microbial carrier in the settling tank is a polyvinylidene chloride material, fine microbial particles in the water to be treated can be captured by the polyvinylidene chloride material. Therefore, the water quality in the item of suspended solids can be further improved, and the quality of the wastewater discharged from the sedimentation tank 20 can be improved.

In the wastewater treatment apparatus of one embodiment,
An oxidation-reduction potentiometer for measuring the oxidation-reduction potential in the nitrification denitrification tank;
A hydrogen donor addition section for introducing a hydrogen donor into the nitrification / denitrification tank based on the output of the oxidation / reduction potentiometer so that the oxidation / reduction potential in the nitrification / denitrification tank is within a predetermined range. Features.

  In the wastewater treatment apparatus of this embodiment, the oxidation-reduction potential in the nitrification denitrification tank is controlled within a predetermined range. Here, since nitrification is a kind of oxidation and denitrification is a kind of reduction, if the oxidation-reduction potential in the nitrification denitrification tank is controlled within a predetermined range, nitrification in the nitrification denitrification tank (Primary) denitrification is performed smoothly. For example, when the nitrification is performed, if the oxidation state in the water tank is too strong, it takes a long time to bring the nitrification denitrification tank into a reduced state in order to perform the denitrification. Further, since the hydrogen donor addition section introduces the hydrogen donor into the nitrification denitrification tank, (first) denitrification of the water to be treated is reliably performed in the nitrification denitrification tank.

In the wastewater treatment apparatus of one embodiment,
In the micro / nano bubble generation tank, a circulation pump for circulating the water to be treated in the micro / nano bubble generation tank is provided,
Equipped with a microbial concentration meter for measuring the microbial concentration in the nitrification denitrification tank,
A microbial concentration control unit is provided for controlling the number of revolutions of the circulation pump or the operation or stoppage thereof so that the microbial concentration in the nitrification denitrification tank falls within a predetermined range based on the output of the microbial concentration meter. .

  The present inventor has found that there is a correlation between the amount of micro / nano bubbles generated in the micro / nano bubble generation tank and the microbial concentration in the nitrification / denitrification tank. If the number of rotations of the circulation pump is increased, the discharge pressure of the circulation pump increases and the amount of micro / nano bubbles generated increases. When the amount of micro-nano bubbles generated increases, microorganisms in the nitrification / denitrification tank are activated and proliferated, and the microorganism concentration increases. Conversely, if the rotational speed of the circulation pump is slowed, the discharge pressure of the circulation pump is reduced, and the amount of micro-nano bubbles generated is reduced. When the generation amount of micro / nano bubbles decreases, the concentration of microorganisms in the nitrification denitrification tank decreases. Therefore, in the wastewater treatment apparatus of this embodiment, the microorganism concentration control unit controls the rotation speed, operation, or stop of the circulation pump provided in the micro / nano bubble generation tank based on the output of the microorganism concentration meter. As a result, the microorganism concentration in the nitrification denitrification tank falls within a predetermined range. Therefore, nitrification and denitrification are surely performed in the nitrification denitrification tank.

In one embodiment of the wastewater treatment apparatus, the micro-nano bubble generation tank is provided with a plurality of circulation pumps for circulating the treated water in the micro-nano bubble generation tank,
Equipped with a microbial concentration meter for measuring the microbial concentration in the nitrification denitrification tank,
A microbial concentration control unit is provided for controlling the number of the circulating pumps operated so that the microbial concentration in the nitrification denitrification tank falls within a predetermined range based on the output of the microbial concentration meter.

  In the wastewater treatment apparatus of this embodiment, the microorganism concentration control unit controls the number of the circulating pumps provided in the micro / nano bubble generation tank based on the output of the microorganism concentration meter. As a result, the microorganism concentration in the nitrification denitrification tank falls within a predetermined range. Therefore, nitrification and denitrification are surely performed in the nitrification denitrification tank. For example, two units are operated to increase the microbial concentration in the nitrification denitrification tank, one unit is operated to maintain the normal microbial concentration, and both are stopped when the microbial concentration in the nitrification denitrification tank is decreased. Can be considered.

  In the wastewater treatment apparatus of one embodiment, the mixture introduction unit contains treated water taken out from the raw water tank, return sludge water taken out from the settling tank, and micro / nano bubbles taken out from the micro / nano bubble generation tank. It is characterized by comprising a mixing tank for introducing water and mixing to obtain the above mixture.

  In the wastewater treatment apparatus according to this embodiment, the water to be treated, the returned sludge water, and the micro-nano bubble-containing water can be adapted from an earlier time point in the mixing tank. Therefore, the activation of the microorganism can be achieved from an early point in time.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 schematically shows the configuration of the waste water treatment apparatus according to the first embodiment of the present invention.

  This waste water treatment apparatus generally includes a raw water tank 1 for storing raw water (drain water) 90 as treated water to be treated, and nitrification and primary dehydration for treated water 90A taken out from the raw water tank 1. A nitrification / denitrification tank 22 that performs nitrification, a denitrification tank 31 that performs secondary denitrification on the treated water 90B from the nitrification / denitrification tank 22, and aeration of the treated water 90C from the denitrification tank 31 The re-aeration tank 32 for performing the above and the sedimentation tank 20 for collecting the treated water 90D from the re-aeration tank 32 and separating it into supernatant water and return sludge water are provided in this order. Basically, the supernatant water in the precipitation tank 20 is discharged through the discharge pipe 27 as a treated waste water from which nitrogen has been removed. Further, the waste water treatment apparatus includes a micro / nano bubble generation tank 16, a mixing tank 17 as a mixture introduction unit, a micro / nano bubble generation aid tank 24 as a part of the micro / nano bubble generation aid addition unit, and a hydrogen donor addition A hydrogen donor tank 29 as a part of the unit and a control unit 70 for controlling the operation of the entire apparatus are provided.

  In this wastewater treatment apparatus, specifically, wastewater containing suspended solids of any industry is treated, but it can also be adapted to wastewater that does not contain suspended solids.

  Raw water (drainage) 90 as treated water is introduced into the raw water tank 1 through an inflow pipe 2 from a factory (not shown). The raw water 90 introduced into the raw water tank 1 is pumped by the raw water tank pump 3 and transferred to the nitrification denitrification tank 22.

  In the nitrification / denitrification tank 22, an aeration pipe 5 is installed in the lower part as an aeration section for aeration of the contents of the nitrification / denitrification tank 22. The diffuser pipe 5 is connected to the intermittent operation blower 4 by piping. When the intermittent operation blower 4 is operated, air is discharged into the nitrification / denitrification tank 22 through the air diffusion pipe 5, and the dissolved oxygen in the nitrification / denitrification tank 22 increases. Accordingly, the contents of the nitrification / denitrification tank 22 are agitated. In addition, in the nitrification / denitrification tank 22, an underwater agitator 37 as a stirring unit for stirring the contents of the nitrification / denitrification tank 22 is provided separately from the air diffusion pipe 5. In the nitrification / denitrification tank 22, a microbial concentration meter 6 for measuring the microorganism concentration in the nitrification / denitrification tank 22 and a redox potential meter 34 for measuring the oxidation / reduction potential in the nitrification / denitrification tank 22 are further provided. ing.

  The microorganism concentration meter 6 and the oxidation-reduction potential meter 34 are combined with a microorganism concentration controller 7 and an oxidation-reduction potential controller 35, respectively. Based on the output of the microorganism concentration meter 6, the microorganism concentration controller 7 transmits a signal to be described later to the circulation pump 10 and the circulation pump 11 installed outside the micro / nano bubble generation tank 16. The microorganism concentration meter 6, the microorganism concentration controller 7, the circulation pump 10 and the circulation pump 11 constitute a microorganism concentration control unit.

  Based on the output of the oxidation-reduction potentiometer 34, the oxidation-reduction potential adjuster 35 installs a signal for introducing a hydrogen donor (in this example, methanol) into the nitrification denitrification tank 22 in the hydrogen donor tank 29. To the hydrogen donor tank metering pump 36. Thereby, the oxidation-reduction potential in the nitrification denitrification tank 22 is controlled within a predetermined range. The specific operation range of the oxidation-reduction potential is −150 mV to −350 mV. Here, since nitrification is a kind of oxidation and denitrification is a kind of reduction, if the oxidation-reduction potential in the nitrification denitrification tank 22 is controlled within a predetermined range, nitrification in the nitrification denitrification tank 22 (Primary) denitrification is performed smoothly. For example, when the nitrification is performed, if the oxidation state in the nitrification denitrification tank 22 is too strong, it takes a long time to bring the nitrification denitrification tank 22 into a reduced state in order to perform the denitrification. Moreover, since the hydrogen donor addition part introduces the hydrogen donor into the water tank, the denitrification of the water to be treated is reliably performed in the water tank. The oxidation-reduction potentiometer 34, the oxidation-reduction potential controller 35, the hydrogen donor tank metering pump 36, and the hydrogen donor tank 29 constitute a hydrogen donor addition unit.

  The nitrification in the nitrification denitrification tank 22 and the first denitrification will be described in detail later.

  In the denitrification tank 31, an underwater stirrer 39 for constantly stirring the contents of the denitrification tank 31 is provided in the lower part. In the denitrification tank 31, an oxidation-reduction potentiometer 34 that measures the oxidation-reduction potential in the denitrification tank 31 is provided. The oxidation-reduction potentiometer 34 is combined with the oxidation-reduction potential controller 35 as in the nitrification denitrification tank 22. Then, a signal for introducing the hydrogen donor into the denitrification tank 31 is sent to the hydrogen donor tank metering pump 30 installed in the hydrogen donor tank 29. As a result, the oxidation-reduction potential in the denitrification tank 31 is reduced. It is controlled within a predetermined range. Thereby, denitrifying bacteria reduce nitrate nitrogen in the treated water 90B to form nitrogen gas. This removes nitrogen. That is, the second denitrification is reliably performed on the water to be treated 90B.

  The denitrification tank 31 contains a string-like polyvinylidene chloride material 23 as a microorganism carrier for propagating microorganisms. The string-like or ring-like polyvinylidene chloride material 23 has a relatively large surface area and is suitable for breeding microorganisms. In this denitrification tank 31, denitrification bacteria can be propagated at a high concentration at the string-like polyvinylidene chloride material 23, so that the denitrification efficiency can be increased.

  In the re-aeration tank 32, a diffusion tube 5 for aerating the contents of the re-aeration tank 32 is installed in the lower part. The air diffuser 5 is connected to the blower 38 by piping. The blower 38 always operates, and air is discharged into the re-aeration tank 32 through the air diffusion pipe 5. Thereby, the dissolved oxygen in the re-aeration tank 32 increases. Accordingly, the contents of the re-aeration tank 32 are agitated. Therefore, an excessive or appropriate amount of hydrogen donor (in this example, methanol) remaining in the water to be treated 90C is easily oxidized and decomposed. In this re-aeration tank 32, water containing micro-nano bubbles can be introduced through a valve 33 from a micro-nano bubble generation tank 16 described in detail later. Therefore, the aerobic microorganisms in the re-aeration tank 32 are in an activated state. Therefore, an excessive or appropriate amount of hydrogen donor remaining in the water to be treated 90C can be decomposed by an aerobic microorganism.

  In the sedimentation tank 20, a sludge return pump 18 for extracting the return sludge water containing the precipitated sludge and returning it to the mixing tank 17, and a supernatant water pump 21 for pumping the supernatant water and returning it to the micro / nano bubble generation tank 16. And are installed. The sludge return pump operates at a capacity that can transfer about three times the raw water amount per day, that is, the circulating water amount is three times the raw water amount per day. The settling tank 20 is provided with a scraper 18 that is used when the precipitated sludge is drawn out. When the amount of microorganisms in each of the nitrification denitrification tank 22, the denitrification tank 31, the re-aeration tank 32, and the precipitation tank 20 is large, surplus microbial sludge is extracted from the precipitation tank 20 using the scraper 19. In the sedimentation tank 20 as well, denitrification is performed by denitrifying bacteria present in the treated water 90D.

  In the micro / nano bubble generating tank 16, the supernatant water taken out from the sedimentation tank 20 by the supernatant water pump 21 is stored as treated water 90E. In the micro / nano bubble generation tank 16, two micro / nano bubble generators 8 and 9 are installed in a state of being immersed in the water to be treated 90E. The micro / nano bubble generators 8 and 9 adjust the water containing micro / nano bubbles by generating micro / nano bubbles in the water to be treated 90E.

  Here, “micro / nano bubble” means a bubble having a diameter of several hundred nm to 10 μm. “Microbubbles” are defined as “bubbles having a diameter of 10 to several tens of μm when they are generated”. The microbubbles contract after generation and change to “micronano bubbles”. Some shrink in water and eventually disappear (complete dissolution). “Nanobubble” means a bubble having a diameter of several hundred nm or less (typically 100 to 200 nm). “Micro-nano bubbles” can be described as bubbles in which micro-bubbles and nano-bubbles are mixed.

  The necessary circulating water is supplied to the micro / nano bubble generator 8 and the micro / nano bubble generator 9 by an inverter driven circulation pump 11 and a circulation pump 12, respectively. Necessary air for the micro / nano bubble generator 8 is supplied through the air suction pipe 13 and the valve 12, and necessary air for the micro / nano bubble generator 9 is supplied through the air suction pipe 15 and the valve 14. . The amount of micro / nano bubbles generated is effective when the total capacity of the wastewater treatment tank is 300 tons and the amount of micro / nano bubbles generated is 2 L / min.

  The rotational speeds of the circulation pump 10 and the circulation pump 11 are controlled by an inverter based on a signal from the microorganism concentration controller 7. Thereby, the discharge amount of the circulation pump 10 and the circulation pump 11 is controlled, and the micro-nano bubble generation amount of the micro-nano bubble generator 8 and the micro-nano bubble generator 9 is controlled accordingly.

  The amount of micro / nano bubbles generated in the micro / nano bubble generation tank 16 is controlled not only by the number of rotations of the circulation pumps 10 and 11, but also by operation or stop of the circulation pumps 10 and 11, It is also controlled by the number of circulating pumps 10 and 11 (2 units, 1 unit, or 0 units).

  The micro-nano bubble generation auxiliary agent stored in the micro-nano bubble generation auxiliary agent tank 24 is added to the micro-nano bubble generation tank 16 by the generation auxiliary agent pump 25. Specific examples of the micro / nano bubble generation aid include surfactants having good microbial degradability.

  Returned sludge water taken out from the precipitation tank 20 and water containing micro-nano bubbles taken out from the micro-nano bubble generation tank 16 are introduced into the mixing tank 17 through a valve 33 and mixed. The resulting mixture is introduced into the nitrification denitrification tank 22.

  Here, a method for adjusting the microorganism concentration in the nitrification denitrification tank 22 will be described. In this waste water treatment apparatus, the microorganism concentration in the nitrification denitrification tank 22 is controlled by the amount of micro-nano bubbles.

  Specifically, as mentioned above, the microorganism concentration is measured by the microorganism concentration meter 6. And the discharge amount of the circulation pump 10 and the circulation pump 11 is controlled in the micro / nano bubble generation tank 16 by the signal of the microorganism concentration controller 7 based on the output of the microorganism concentration meter, and the micro / nano bubble generator 8 and the micro The amount of micro / nano bubbles generated by the nano bubble generator 9 is controlled. Thereby, the amount of micro / nano bubbles in the water containing micro / nano bubbles is controlled. For example, if the number of rotations of the circulation pumps 10 and 11 is increased, the discharge pressure of the circulation pumps 10 and 11 increases and the amount of micro-nano bubbles generated increases. When the amount of micro / nano bubbles generated in the micro / nano bubble generation tank 16 increases, microorganisms in the nitrification / denitrification tank 22 are activated and proliferated, and the microorganism concentration increases. On the other hand, if the rotation speed of the circulation pumps 10 and 11 is slowed, the discharge pressure of the circulation pumps 10 and 11 decreases, and the amount of micro-nano bubbles generated decreases. When the amount of micro / nano bubbles generated in the micro / nano bubble generation tank 16 decreases, the concentration of microorganisms in the nitrification / denitrification tank 22 decreases. As a result, the microorganism concentration in the nitrification / denitrification tank 22 is controlled based on the output of the microorganism concentration meter to be within a predetermined range. In addition, about 8,000-10,000 ppm is selected by the MLSS (Mixed Liquor Suspend Solid) density | concentration as a specific numerical value of microorganism concentration.

  The microbial concentration in the nitrification denitrification tank 22 is not only controlled by the number of rotations of the circulation pumps 10 and 11, but also controlled by the operation or stop of the circulation pumps 10 and 11, It is also controlled by 11 operating units (2 units, 1 unit, or 0 units). For example, when increasing the microbial concentration in the nitrification denitrification tank 22, two units are operated, when maintaining the normal microbial concentration, one unit is operated, and when reducing the microbial concentration in the nitrification denitrification tank 22, both units are stopped. Control to do is conceivable.

  Next, nitrification in the nitrification denitrification tank 22 and (first) denitrification will be specifically described.

  In this waste water treatment apparatus, the microorganisms introduced from the mixing tank 17 into the nitrification / denitrification tank 22 are activated by the micro / nano bubbles. Here, when the control unit 70 operates the intermittent operation blower 4 and the diffuser pipe 5 to aerate the contents of the nitrification / denitrification tank 22, water 90A to be treated is obtained by the aerobic microorganisms (nitrifying bacteria) activated by the micro / nano bubbles. The ammoniacal nitrogen in it is easily oxidized to nitrate nitrogen. Therefore, nitrification is reliably performed. Thereafter, when the control unit 70 deactivates the intermittent operation blower 4 and the air diffuser 5, oxygen is not supplied into the nitrification denitrification tank 22. If the residual oxygen in the nitrification denitrification tank 22 is consumed by microorganisms, the nitrification denitrification tank 22 becomes oxygen-free or low-oxygen. Then, the treated water 90A is devaginated by anaerobic microorganisms (particularly devaginating bacteria) activated by the micro / nano bubbles. In addition, a hydrogen donor (in this example, methanol) is added to the water to be treated 90A by the hydrogen donor addition portions 34, 35, 36, and 29, and a reduced state is created. In addition, when performing the above denitrification, the controller 70 operates the underwater agitator 37 to agitate the contents of the nitrification denitrification tank 22, so that the devagination can proceed efficiently. In the first denitrification in the nitrification denitrification tank 22, the removal rate of total nitrogen is small, but a certain degree of denitrification is performed.

  In this waste water treatment apparatus, since nitrification and denitrification are performed in the same water tank (that is, nitrification denitrification tank), it can be performed with simple equipment and at low cost (particularly, low initial cost). Further, when the denitrification is performed, the control unit 70 deactivates the intermittent operation blower 4 and the air diffuser 5 so that energy is saved and the running cost is reduced. Moreover, in this waste water treatment apparatus, the microorganism concentration in the nitrification denitrification tank 22 can be controlled by electrical control by adjusting the amount of micro / nano bubbles in the water containing micro / nano bubbles by the microorganism concentration control units 6, 7, 10, and 11. . Specifically, increasing the amount of micro-nano bubbles increases the microbial concentration, and decreasing the amount of micro-nano bubbles decreases the microbial concentration. Therefore, the adjustment and management of the facilities become easy.

  Further, if the raw water 90 is introduced into the micro / nano bubble generation tank 16, the micro / nano bubble discharge ports (holes) of the micro / nano bubble generators 8 and 9 are generally small. There is a risk of clogging the holes of the generators 8 and 9. On the other hand, in the waste water treatment apparatus of the present invention, in the micro / nano bubble generation tank 16, the micro / nano bubble is generated by adding micro / nano bubbles to the supernatant water taken out from the sedimentation tank 20 by the micro / nano bubble generators 8 and 9. Is adjusted. That is, the micro / nano bubble generators 8 and 9 are not immersed in the raw water 90. Therefore, the floating substance contained in the raw water 90 does not clog the holes of the micro / nano bubble generators 8 and 9.

  In this embodiment, as the nano / nano bubble generators 8 and 9, commercially available products manufactured by Nano Planet Research Laboratory and those of Auratec Co., Ltd. are employed. However, the manufacturer of the micro / nano bubble generator is not limited. Other companies' micro-nano bubble generators include, for example, micro-bubble water production equipment from Seika Sangyo Co., Ltd., micro-bubble water production equipment from Resource Development Co., Ltd., and micro-bubble water production equipment from Nomura Electronics Co., Ltd. it can.

(Second Embodiment)
FIG. 2 schematically shows the configuration of the waste water treatment apparatus according to the second embodiment of the present invention.

  Compared with the first embodiment, the waste water treatment apparatus of the second embodiment is not limited to the denitrification tank 31 but also in the nitrification denitrification tank 22 only in that a string-like polyvinylidene chloride material 23 as a microorganism carrier is accommodated. Is different. Therefore, in FIG. 2, the same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this waste water treatment apparatus, since the polyvinylidene chloride filler 23 is accommodated in the nitrification denitrification tank 22, microorganisms activated by the micro-nano bubbles adhere to the polyvinylidene chloride filler 23 and propagate. As a result, the microorganism concentration in the nitrification / denitrification tank 22 is increased, and the nitrification and denitrification processes are stabilized. Therefore, even when the quality of the inflowing raw water 90 fluctuates, the treatment can be performed stably.

  In addition, when it turns out by the measurement by water sampling that the microorganism concentration of the nitrification denitrification tank 22 increased, either the circulation pump 10 or the circulation pump 11 is stopped, and the micro / nano bubble generation in the micro / nano bubble generation tank 16 occurs. By reducing the amount, the microbial concentration in the nitrification / denitrification tank 22 can be lowered.

  Further, when the concentration of microorganisms is drastically reduced, both the circulation pump 10 and the circulation pump 11 can be stopped to achieve the object.

  On the other hand, if it is found from the measurement by sampling that the microbial concentration in the nitrification / denitrification tank 22 has decreased, both the circulation pump 10 and the circulation pump 11 are operated, and the micro / nano bubbles in the micro / nano bubble generation tank 16 are operated. The generation amount can be increased, and the microorganism concentration in the nitrification denitrification tank 22 can be increased.

(Third embodiment)
FIG. 3 schematically shows the configuration of the waste water treatment apparatus according to the third embodiment of the present invention.

  Compared with the first embodiment, the waste water treatment apparatus of the third embodiment is not limited to the denitrification tank 31 but only in the re-aeration tank 32 in that the string-like polyvinylidene chloride material 23 as a microorganism carrier is accommodated. Is different. Therefore, in FIG. 3, the same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this waste water treatment apparatus, since the polyvinylidene chloride filler 23 is accommodated in the re-aeration tank 32, microorganisms activated by the micro-nano bubbles adhere to the polyvinylidene chloride filler 23 and propagate. As a result, the microorganism concentration in the re-aeration tank 32 is increased, and the treatment is stabilized.

  In addition, when it is found that the microorganism concentration in the nitrification / denitrification tank 22 has increased by the measurement by sampling water, either the circulation pump 10 or the circulation pump 11 is stopped as described in the second embodiment. Thus, the amount of micro / nano bubbles generated in the micro / nano bubble generation tank 16 can be reduced, and the microorganism concentration in the nitrification / denitrification tank 22 can be lowered.

  Further, when the concentration of microorganisms is drastically reduced, both the circulation pump 10 and the circulation pump 11 can be stopped to achieve the object.

  On the other hand, if it is found from the measurement by sampling that the microbial concentration in the nitrification / denitrification tank 22 has decreased, both the circulation pump 10 and the circulation pump 11 are operated, and the micro / nano bubbles in the micro / nano bubble generation tank 16 are operated. The generation amount can be increased, and the microorganism concentration in the nitrification denitrification tank 22 can be increased.

(Fourth embodiment)
FIG. 4 schematically shows the configuration of the waste water treatment apparatus according to the fourth embodiment of the present invention.

  Compared with the first embodiment, the waste water treatment apparatus of the fourth embodiment does not directly introduce the raw water 90 into the nitrification / denitrification tank 22, but once introduces the raw water 90 into the mixing tank 17 and nitrifies and removes it as a mixture. Only the point of introduction into the nitriding tank 22 is different. Therefore, in FIG. 4, the same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the waste water treatment apparatus of the fourth embodiment, the water to be treated taken out from the raw water tank 1 is mixed together with the returned sludge water taken out from the sedimentation tank 20 and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank 16. It is introduced into the tank 17. Then, after mixing them into a mixture, the mixture is introduced into the nitrification denitrification tank 22.

  Thereby, in the mixing tank 17, the water to be treated (raw water), the returned sludge water, and the water containing micro-nano bubbles can be blended in from an early point in time. Therefore, the activation of the microorganism can be achieved from an early point in time. That is, when the micro-nano bubbles are abundant, the microorganisms in the returned sludge water having a high microorganism concentration can be efficiently activated. At the same time, the activated microorganism can immediately start decomposing the components contained in the water to be treated.

  In addition, when it is found that the microorganism concentration in the nitrification / denitrification tank 22 has increased by the measurement by sampling water, either the circulation pump 10 or the circulation pump 11 is stopped as described in the second embodiment. Thus, the amount of micro / nano bubbles generated in the micro / nano bubble generation tank 16 can be reduced, and the microorganism concentration in the nitrification / denitrification tank 22 can be lowered.

  Further, when the concentration of microorganisms is drastically reduced, both the circulation pump 10 and the circulation pump 11 can be stopped to achieve the object.

  On the other hand, if it is found from the measurement by sampling that the microbial concentration in the nitrification / denitrification tank 22 has decreased, both the circulation pump 10 and the circulation pump 11 are operated, and the micro / nano bubbles in the micro / nano bubble generation tank 16 are operated. The generation amount can be increased, and the microorganism concentration in the nitrification denitrification tank 22 can be increased.

(Fifth embodiment)
FIG. 5 schematically shows the configuration of the waste water treatment apparatus according to the fifth embodiment of the present invention.

  Compared with the third embodiment, the waste water treatment apparatus of the fifth embodiment accommodates not only the denitrification tank 31 and the re-aeration tank 32 but also the precipitation tank 20 with the string-like polyvinylidene chloride material 23 as a microorganism carrier. Only the differences are different. Therefore, in FIG. 5, the same elements as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this waste water treatment apparatus, since the polyvinylidene chloride filler 23 is accommodated in the precipitation tank 20, microorganisms activated by the micro-nano bubbles adhere to the polyvinylidene chloride material 23 and propagate. As a result, the microorganism concentration in the precipitation tank 20 is increased, and the treatment is stabilized. Thereby, the denitrification efficiency as a whole can be improved. Further, in the sedimentation tank 20, fine microbial particles (such as floc) in the water to be treated 90 </ b> D can be captured by the polyvinylidene chloride material 23. Therefore, the water quality in the item of suspended solids can be further improved, and the quality of the wastewater discharged from the sedimentation tank 20 can be improved.

(Sixth embodiment)
FIG. 6 schematically shows the configuration of the waste water treatment apparatus according to the sixth embodiment of the present invention.

  Compared to the first embodiment, the waste water treatment apparatus of the sixth embodiment is a stirring unit that stirs the contents of the nitrification denitrification tank 22 by a motor disposed above the water surface instead of the underwater stirrer 37. The only difference is that it includes a driven stirrer 40 (two in this example). Therefore, in FIG. 6, the same elements as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Since the waste water treatment apparatus of the sixth embodiment includes the most frequently used stirrer 40, the waste water treatment apparatus is configured at low cost (particularly, initial cost). Further, since the motor of the stirrer 40 is not submerged in water, there is no leakage due to corrosion that often occurs in the underwater stirrer.

  The stirring unit for stirring the contents of the nitrification denitrification tank 22 is not limited to an underwater stirrer, and any type of stirring unit may be used as long as stirring can be performed.

(Seventh embodiment)
FIG. 7 schematically shows the configuration of a microorganism reaction tank (bioreactor) according to a seventh embodiment of the present invention.

  This microbial reaction tank is a reaction tank for performing brewing, fermentation, pharmaceutical production and the like by utilizing the action of microorganisms. Also in the field of microbial reaction tanks for brewing, fermentation, pharmaceutical production, etc., a microorganism can be activated by micro-nano bubbles and a product can be produced by the action of the activated microorganism.

  Two micro / nano bubble generators 8 and 9 are installed in the reaction tank 26 of the microorganism reaction tank. In addition, an oxidation-reduction potentiometer 34 and a microorganism concentration meter 6 are accommodated in the lower part of the reaction tank 26. Needless to say, accessories such as a stirrer (not shown) and a thermometer (not shown) for agitating the contents of the reaction tank 26 are installed in the microorganism reaction tank. The operation of the entire microbial reaction tank is controlled by the control unit 71.

  In this example, water containing wheat, hops, corn starch, etc., which are raw materials for brewing beer, is treated in the reaction tank 26 through the raw material introduction pipe 27 provided at the upper part of the reaction tank 26 in this example. be introduced.

  The micro / nano bubble generators 8 and 9 are configured such that the oxidation-reduction potentiometer 35 is connected to the circulation pump 10 based on the output (measured value) of the oxidation-reduction potentiometer 34 so that the oxidation-reduction potential in the reaction tank 26 is within a predetermined range. And on / off of the circulation pump 11 is controlled. Thereby, the breeding conditions of the anaerobic microorganisms in the reaction tank 26 are maintained.

  At the same time, the micro / nano bubble generators 8 and 9 control the introduction amount of the micro / nano bubbles into the reaction tank 26 so that the microorganism concentration in the reaction tank 26 falls within a predetermined range.

  The necessary circulating water is supplied to the micro / nano bubble generator 8 and the micro / nano bubble generator 9 by an inverter driven circulation pump 11 and a circulation pump 12, respectively. Necessary air for the micro / nano bubble generator 8 is supplied through the air suction pipe 13 and the valve 12, and necessary air for the micro / nano bubble generator 9 is supplied through the air suction pipe 15 and the valve 14. .

  The rotational speeds of the circulation pump 10 and the circulation pump 11 are controlled by an inverter based on a signal from the microorganism concentration controller 7. Thereby, the discharge amount of the circulation pump 10 and the circulation pump 11 is controlled, and the micro-nano bubble generation amount of the micro-nano bubble generator 8 and the micro-nano bubble generator 9 is controlled accordingly. Thereby, the microorganism concentration in the reaction tank 26 is controlled within a predetermined range.

  Thus, in this microorganism reaction tank, the operation of the micro / nano bubble generator 8 and the micro / nano bubble generator 9 is controlled based on both the output of the microorganism concentration meter 6 and the output of the oxidation-reduction potentiometer 34. As a result, the microorganism concentration and oxidation-reduction potential in the reaction tank 26 can be controlled within a predetermined range, and the target substance can be produced with the desired quality by operating the reaction tank 26 in an aerobic state or an anaerobic state. .

  A product obtained by culturing the target microorganism concentration and cultivating at the oxidation-reduction potential is taken out through a pipe 29 provided at the lower part of the reaction vessel 26.

  The waste water treatment apparatus of the first embodiment shown in FIG. 1 was actually manufactured, and the effect confirmation test was performed.

In the waste water treatment apparatus, the capacity of the raw water tank 1 is about 1 m ³ , the capacity of the nitrification denitrification tank 22 is 8 m ³ , the capacity of the denitrification tank 31 is 4 m ³ , the capacity of the re-aeration tank 32 is 2 m ³ , and the capacity of the sedimentation tank 20. is 3m ^3, the capacity of the micro-nano bubble generation tank 16 is 0.2 m ^3, the capacity of the mixing tank 17 was set to the 0.2 m ^3. Then, drainage from the factory was introduced and a trial run was conducted for about 3 months.

After the trial operation, the concentration of TOC [total organic carbon] at the inlet to the raw water tank 1 and the concentration of TOC at the outlet of the precipitation tank 20 were measured and compared. As a result, the TOC removal rate was 88%. Thus, according to the present invention, favorable results were obtained.

It is a figure which shows typically the structure of the waste water treatment equipment of 1st Embodiment of this invention. It is a figure which shows typically the structure of the waste water treatment equipment of 2nd Embodiment of this invention. It is a figure which shows typically the structure of the waste water treatment equipment of 3rd Embodiment of this invention. It is a figure which shows typically the structure of the waste water treatment equipment of 4th Embodiment of this invention. It is a figure which shows typically the structure of the waste water treatment equipment of 5th Embodiment of this invention. It is a figure which shows typically the structure of the waste water treatment equipment of 6th Embodiment of this invention. It is a figure which shows typically the structure of the microorganisms reaction tank of 7th Embodiment of this invention.

Explanation of symbols

1 Raw water tank 2 Inflow piping
4 Intermittent operation blower 5 Aeration pipe 6 Microbial concentration meter 7 Microbial concentration controller 8, 9 Micro-nano bubble generator 10, 11 Circulation pump 16 Micro-nano bubble generation tank 17 Mixing tank 20 Precipitation tank 22 Aeration tank 24 Micro-nano bubble generation aid tank 29 Hydrogen donor tank 31 Denitrification tank 32 Re-aeration tank 34 Redox potential meter 37, 39 Underwater stirrer 40 Stirrer

Claims (21)

  Treated water to be treated and water containing micro-nano bubbles are introduced into one aquarium, nitrified by the action of aerobic microorganisms in the aquarium, and then denitrified by the action of anaerobic microorganisms in the aquarium Wastewater treatment method characterized by. The waste water treatment method according to claim 1,
A wastewater treatment method, wherein the micronanobubble-containing water and microbial sludge are mixed and introduced into the water tank. The waste water treatment method according to claim 1,
A wastewater treatment method, wherein when the nitrification is performed, the contents of the water tank are aerated by an aeration unit. In the waste water treatment method according to claim 3,
A wastewater treatment method, wherein when performing the denitrification, aeration by the aeration unit is stopped, and the contents of the water tank are agitated by the agitation unit. The waste water treatment method according to claim 1,
A wastewater treatment method characterized by repeating the nitrification and the denitrification in the water tank alternately and periodically. The waste water treatment method according to claim 2,
The microbial sludge is obtained as return sludge water in a sedimentation tank provided downstream of the water tank, and the micronanobubble-containing water is added to the return sludge water so that the microorganism concentration in the water tank is within a predetermined range. A wastewater treatment method characterized by controlling and mixing. A water tank into which treated water to be treated is introduced;
A mixture introduction part for mixing and introducing micro-nano bubble-containing water and microbial sludge into the water tank;
An aeration section for aeration of the contents of the aquarium,
A controller that operates the aeration unit so as to perform nitrification by the action of aerobic microorganisms in the aquarium, and then deactivates the aeration unit so as to perform denitrification by the action of anaerobic microorganisms in the aquarium. A wastewater treatment apparatus characterized by comprising. The waste water treatment apparatus according to claim 7,
A stirring section for stirring the contents of the water tank,
The control unit operates the aeration unit so as to perform nitrification by the action of aerobic microorganisms in the water tank, and after deactivating the stirring unit, performs denitrification by the action of anaerobic microorganisms in the water tank. As described above, the waste water treatment apparatus is characterized in that the aeration unit is deactivated and the agitation unit is operated. The waste water treatment apparatus according to claim 7,
A stirring section for stirring the contents of the water tank,
The control unit operates the aeration unit and performs the nitrification with the agitation unit deactivated so as to perform continuous treatment of drainage, and deactivates the aeration unit and operates the agitation unit. The waste water treatment apparatus is characterized in that it performs control to alternately and periodically repeat the period for performing the denitrification by operating. The waste water treatment apparatus according to claim 7,
Provided with a denitrification tank provided downstream from the water tank,
The waste water treatment apparatus, wherein the denitrification is further performed in the denitrification tank following the denitrification in the water tank. The waste water treatment apparatus according to claim 7,
An oxidation-reduction potentiometer for measuring the oxidation-reduction potential in the water tank;
Drainage characterized by comprising a hydrogen donor addition section for introducing a hydrogen donor into the water tank so that the redox potential in the water tank falls within a predetermined range based on the output of the redox potentiometer. Processing equipment. The waste water treatment apparatus according to claim 7,
A microbial concentration meter for measuring the microbial concentration in the water tank is provided,
Drainage characterized by comprising a microorganism concentration control unit that controls the amount of micro-nano bubbles introduced into the water tank so that the microorganism concentration in the water tank falls within a predetermined range based on the output of the microorganism concentration meter. Processing equipment. Raw water tank for storing raw water as treated water to be treated;
A nitrification and denitrification tank for performing nitrification and primary denitrification on the water to be treated taken out from the raw water tank;
A denitrification tank that performs secondary denitrification on the water to be treated from the nitrification denitrification tank;
A re-aeration tank for aeration of the treated water from the denitrification tank;
In addition to sequentially providing a sedimentation tank that collects treated water from the re-aeration tank and separates it into supernatant water and return sludge water,
A micro / nano bubble generating tank for adjusting micro / nano bubble-containing water by generating micro / nano bubbles with a micro / nano bubble generator for the supernatant water taken out from the precipitation tank;
A mixture introduction unit for adjusting the mixture of the returned sludge water taken out from the settling tank and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank and introducing the mixture into the nitrification / denitrification tank,
The nitrification / denitrification tank is provided with an aeration section for aeration of the contents of the nitrification / denitrification tank, and a stirring section for stirring the contents of the nitrification / denitrification tank,
The aeration unit is operated so as to perform the nitrification by the action of aerobic microorganisms in the nitrification denitrification tank, and the first denitrification is performed in the nitrification denitrification tank, and the period during which the agitation unit is not operated. Thus, a wastewater treatment apparatus comprising: a control unit that performs a control in which the aeration unit is inoperative and the period in which the agitation unit is operated is alternately and periodically repeated. The waste water treatment apparatus according to claim 13,
A wastewater treatment apparatus comprising a micro / nano bubble generation aid addition unit for introducing a micro / nano bubble generation aid into the micro / nano bubble generation tank. The waste water treatment apparatus according to claim 13,
The mixture introduction part is provided with a mixing tank that introduces and mixes the return sludge water taken out from the precipitation tank and the micro / nano bubble-containing water taken out from the micro / nano bubble generation tank to adjust the mixture. A featured wastewater treatment device. The waste water treatment apparatus according to claim 13,
A wastewater treatment apparatus, wherein a microorganism carrier for propagating microorganisms is accommodated in at least one of the nitrification denitrification tank, the denitrification tank, the re-aeration tank, and the precipitation tank. The waste water treatment apparatus according to claim 16,
A wastewater treatment apparatus, wherein the microbial carrier is a string-like or ring-like polyvinylidene chloride material. The waste water treatment apparatus according to claim 13,
An oxidation-reduction potentiometer for measuring the oxidation-reduction potential in the nitrification denitrification tank;
A hydrogen donor addition section for introducing a hydrogen donor into the nitrification / denitrification tank based on the output of the oxidation / reduction potentiometer so that the oxidation / reduction potential in the nitrification / denitrification tank is within a predetermined range. A featured wastewater treatment device. The waste water treatment apparatus according to claim 13,
In the micro / nano bubble generation tank, a circulation pump for circulating the water to be treated in the micro / nano bubble generation tank is provided,
Equipped with a microbial concentration meter for measuring the microbial concentration in the nitrification denitrification tank,
A microbial concentration control unit is provided for controlling the number of revolutions of the circulation pump or the operation or stoppage thereof so that the microbial concentration in the nitrification denitrification tank falls within a predetermined range based on the output of the microbial concentration meter. Wastewater treatment equipment. The waste water treatment apparatus according to claim 13,
The micro-nano bubble generation tank is provided with a plurality of circulation pumps for circulating the water to be treated in the micro-nano bubble generation tank,
Equipped with a microbial concentration meter for measuring the microbial concentration in the nitrification denitrification tank,
A wastewater treatment apparatus comprising a microorganism concentration control unit that controls the number of operating circulating pumps so that the microorganism concentration in the nitrification denitrification tank falls within a predetermined range based on the output of the microorganism concentration meter. The waste water treatment apparatus according to claim 13,
The mixture introduction unit introduces the water to be treated taken out from the raw water tank, the returned sludge water taken out from the settling tank, and the micro / nano bubble-containing water taken out from the micro / nano bubble generating tank, and mixes them. A wastewater treatment apparatus comprising a mixing tank for obtaining a mixture.

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