KR20130020596A - Waste water treatment apparatus - Google Patents

Abstract

PURPOSE: A waste water treatment facility is provided to save energy while nitrifying partially by reducing the amount of aeration in an aeration tank. CONSTITUTION: A waste water treatment facility includes an aeration tank(26), a first anoxic chamber(28), a distribution line(20), and a distribution unit(22). The aeration tank produces nitrified water by nitrifying ammonia in waste water by nitrification bacteria. A first anoxic chamber is installed in the front end of the aeration tank, a part of the nitrified water received from the aeration tank, and the nitrified water is denitrified by denitrification bacteria. A second anoxic chamber is installed in the rear end of the aeration tank, a part of the nitrified water is sent and received from the aeration tank, and the nitrified water is denitrified by denitrification bacteria and sent to and received from the rear end as processed water. A distribution line distributes the waste water to the first anoxic chamber and the second anoxic chamber. A distribution unit is installed in the distribution line and distributes the waste water to the first anoxic chamber and the second anoxic chamber.

Description

Wastewater Treatment System {WASTE WATER TREATMENT APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus, and more particularly, to a technique for nitriding a portion of ammonia nitrogen in wastewater (hereinafter referred to as partial nitriding) to realize energy saving.

Background Art As a wastewater treatment apparatus for removing nitrogen from wastewater containing ammonia nitrogen, an activated sludge circulation variation has conventionally been known. The activated sludge circulation variant is a treatment method using activated sludge, which sends wastewater to an aerobic nitrification tank through an anaerobic denitrification tank, and in this nitriding tank, ammonia Nitrogen is nitrated (oxidized) with nitrate nitrogen. A part of the nitrified water is returned from the nitriding tank to the denitrification tank to convert nitrate nitrogen into nitrogen gas by denitrification bacteria in the activated sludge. Further, the remainder of the treated water nitrified in the nitriding tank is discharged through the final settling basin.

However, in the nitriding treatment with activated sludge, the nitrifying bacteria cannot be maintained at a high concentration in the nitriding tank. Therefore, the high load operation cannot be performed and the nitriding treatment efficiency is poor. In this regard, in recent years, a nitriding-promoting circulation variant in which a carrier including nitrifying bacteria is immobilized in a nitriding tank has been performed (for example, Patent Document 1). As shown in Fig. 6, the nitriding-promoting circulation variant is basically the same as the activated sludge circulation variant, and the nitrided nitriding water in the nitriding tank 1 into which the comprehensive fixation carrier 4 is introduced is denitrated in the denitrification tank 2. The treated water is solid-liquid separated in the final settling basin 3 and then discharged.

In addition, the screening tank 5 which prevents outflow of a support | carrier is provided in the nitriding tank 1 into which the comprehensive fixation support | carrier 4 was thrown in. In the first settling basin 6, clogging substances such as contaminants in the wastewater are removed at the front end where raw water of the wastewater flows.

Japanese Patent Laid-Open No. 2008-012383

 By the way, the ammonia concentration of the discharge regulation value is prescribed | regulated according to the area | region regarding the water quality of the treated water which performed the wastewater treatment, and it does not need to nitrify (complete nitriding) all the ammonia which flows into a wastewater treatment apparatus, and it remains to a predetermined reference amount. In some cases, a standard for allowing so-called partial nitriding may be provided.

However, the conventional wastewater treatment apparatus using a nitriding-promoting circulatory system completely nitrides ammonia and maximizes the total nitrogen (a sum of nitrogen such as ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen) in the treated water. It is designed on the basis of reducing. Therefore, when the wastewater treatment apparatus of the nitriding acceleration type circulation method aiming at complete nitriding is applied to the wastewater treatment apparatus for partial nitriding, there is a problem that it becomes an excess facility. Excessive equipment consumes too much energy. Against this background, there is a demand for a wastewater treatment apparatus suitable for partial nitriding and capable of realizing energy saving.

This invention is made | formed in view of the above-mentioned situation, and an object of this invention is to provide the wastewater treatment apparatus suitable for partial nitriding and which can contribute to energy saving.

According to one aspect of the present invention, there is provided a wastewater treatment apparatus for partially nitriding ammonia nitrogen in organic wastewater to remove nitrogen, wherein the aeration tank for nitrifying the ammonia in the wastewater with nitrifying bacteria to produce nitrified water; A first oxygen-free oxygen tank disposed at the front end, and part of the nitriding water is returned from the exhalation tank, and the nitriding water is denitrified by denitrification bacteria, and is installed at a rear end of the exhalation tank. A second anoxic tank for denitrifying the nitriding water by a denitrification bacterium and sending a portion of the nitriding water to a rear end, and a distribution line for distributing the wastewater to the first anoxic tank and the second anoxic tank; And distribution means for distributing the wastewater to the first anoxic tank and the second anoxic tank, provided in the distribution line.

Preferably, the said distribution means has a quantity adjustment function which adjusts a quantity of water.

Preferably, the nitride bacteria are comprehensively immobilized on a comprehensive immobilization carrier.

Preferably, it is provided in the rear end of the said 2nd oxygen-free tank, and further comprises the aeration tank for improving the property of the sludge in the said treated water, and decomposing the organic component in the said treated water. When activated sludge flows into the final sedimentation basin from the second anoxic tank, sludge rises together with nitrogen gas generated by denitrification reaction in the final sedimentation basin, and may flow out together with the treated water to deteriorate the treated water quality. In addition, in an aerobic tank, a nitriding carrier may be added to perform high-speed nitriding, and since a necessary amount of oxygen for high-speed nitriding is supplied, the aeration intensity of the aerobic tank is increased, and the floc of the activated sludge is dismantled, and the sludge is discharged from the final settling basin. It may be difficult to settle sediment. By providing the aeration tank at the rear end of the second anoxic tank as described above, the flocculation of the activated sludge is reformed because of the aerobic state in which the aeration intensity is weak, thereby increasing the sedimentation properties of the sludge. Moreover, since it becomes aerobic, denitrification reaction hardly progresses even if it flows into a final sedimentation basin, and sludge does not rise.

Preferably, the apparatus further includes measuring means for measuring the ammonia concentration in the treated water and water quantity controlling means for controlling a distribution means having a water quantity adjusting function based on the measurement result of the measuring means.

Preferably, the encapsulation immobilization carrier is filled in the exhalation tank in a state in which the encapsulation immobilization carrier is movably housed in a container in which a plurality of water passages having a size through which the immobilization immobilization carrier does not pass are formed.

According to the wastewater treatment apparatus of the present invention, energy saving can be realized in the case where nitrogen is removed by partially nitriding ammonia nitrogen in organic wastewater.

1 is a configuration diagram of a wastewater treatment apparatus according to a first embodiment.
2 is a flow chart of a wastewater treatment apparatus.
3 is a schematic view showing a container containing a comprehensive fixation carrier.
4 is a configuration diagram of a wastewater treatment apparatus according to a second embodiment.
5 is a configuration diagram of a wastewater treatment apparatus according to a third embodiment.
Fig. 6 is an explanatory diagram of a conventional nitriding accelerated circulation variant.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although this invention is demonstrated by the following preferable embodiment, a change can be made with many methods, without deviating from the range of this invention, and other embodiments other than this embodiment can be used. Accordingly, all modifications within the scope of the present invention are included in the claims.

1 is a schematic configuration diagram of a wastewater treatment apparatus 10 according to a first embodiment. The wastewater treatment apparatus 10 includes a distribution line 20, a distribution means 22 provided at a branch point of the distribution line 20, a first anaerobic tank 24 disposed from an upstream side to a downstream side, and an aerobic tank. (26), the 2nd anoxic tank 28, and the circulation line 30 for conveying from the aerobic tank 26 to the 1st anoxic tank 24 are provided at least. The adjoining 1st anoxic tank 24 and the aerobic tank 26, and the aerobic tank 26 and the 2nd anoxic tank 28 are in liquid communication. The pump 42 is arranged in the circulation line 30.

The first oxygen-free tank 24 is provided with a motor 32 and a stirring blade 34 attached to the motor 32. What is necessary is just to use this stirring blade generally, and even if it is a water-immersion type, it is possible. In the first oxygen-free tank 24, active sludge containing denitrification bacteria is suspended.

An diffuser 36 is provided at the bottom of the aerobic tank 26. The diffuser 36 communicates with a blower not shown. Air sent from the blower is aerated in the aerobic tank 26 from the diffuser 36. Thereby, the inside of the exhalation tank 26 turns into an exhalation state. The tank of the aerobic tank 26 is filled with a plurality of blanket immobilizing carriers 38 in which the nitride bacteria are fixed. The screen 40 is provided in the communication part with the 2nd oxygen-free tank 28 of the aerobic tank 26 in order to prevent the comprehensive fixation support | carrier 38 from flowing out into the 2nd oxygen-free tank 28. In the present embodiment, the nitride bacteria are comprehensively fixed to the comprehensive immobilization carrier 38. However, the present invention is not limited thereto, and instead of the encapsulating immobilizing carrier 38, it is also possible to cope with an activated sludge containing a nitride or a carrier of a general attachment type of plastic or sponge.

Similar to the first anoxic tank 24, the second anoxic tank 28 is provided with a motor 32 and a stirring blade 34 attached to the motor 32. This stirrer should just be used generally, and may be a water type type | mold. In the second oxygen-free tank 28, active sludge containing denitrification bacteria is suspended.

Next, the wastewater treatment by the wastewater treatment apparatus 10 will be described.

Wastewater containing ammonia nitrogen flows into the initial settling basin 50 and sediments and removes solids and contaminants. In addition to the ammonia nitrogen, the wastewater contains contaminants, organic components and the like.

The distribution means 22 is arrange | positioned at the distribution line 20, and is installed. By this distribution means 22, a part of wastewater is sent to the 1st anaerobic tank 24. As shown in FIG. In addition, the activated sludge is sent from the final settling basin 60 to the first oxygen-free tank 24 through the conveying line 62. In addition, a part of the nitrided water produced in the aerobic tank 26 is conveyed to the first anoxic tank 24 via the circulation line 30.

In the first oxygen-free tank 24, the waste water, the activated sludge, and the nitride water are stirred by the stirring blade 34. Using the organic components in the wastewater, the denitrification bacteria in the activated sludge converts the nitrate nitrogen in the nitrified water into nitrogen gas. In the first oxygen-free tank 24, a so-called denitrification reaction is performed.

The wastewater treated in the first anaerobic tank 24 is sent to the aerobic tank 26 from the first anaerobic tank 24. In the aerobic tank 26, under aerobic conditions, ammonia nitrogen in the waste water is oxidized to nitrate nitrogen by nitrifying bacteria of the encapsulating immobilization support 38, thereby producing nitriding water. In the aerobic tank 26, a so-called nitriding reaction is performed. Part of the nitrided water produced in the aerobic tank 26 is conveyed to the first oxygen-free tank 24 through the circulation line 30. In addition, a part of the nitrided water produced in the aerobic tank 26 is delivered to the second anoxic tank 28 arranged at the rear end.

Nitrided water from the aerobic tank 26 and wastewater from the initial settling basin 50 through the distribution line 20 are sent to the second anoxic tank 28. In the second oxygen-free tank 28, the waste water, the activated sludge, and the nitride water are agitated by the stirring blade 34. By using the organic matter in the wastewater, the denitrification bacteria in the activated sludge converts the nitrate nitrogen in the nitrified water into nitrogen gas. Also in the 2nd oxygen-free tank 28, denitrification reaction is performed. The wastewater passed through the distribution line 20 is sent to the second oxygen-free tank 28 to supply the organic components used for the denitrification reaction. In the second oxygen-free tank 28, ammonia nitrogen contained in the wastewater is not substantially treated.

Finally, the treated water treated in the second anaerobic tank 28 is sent to the final settling basin 60 to precipitate and separate the activated sludge to obtain treated water. When the wastewater is treated by the wastewater treatment apparatus 10 of the present embodiment, the treated water discharged from the second anoxic tank 28 contains ammonia nitrogen.

The difference between the conventional wastewater treatment apparatus and the wastewater treatment apparatus of this embodiment is demonstrated. The conventional wastewater treatment apparatus is designed to be completely nitrided to completely remove ammonia in the advanced treatment of wastewater in order to realize the regulation of the total nitrogen concentration T-N and a low regulation value. In the aerobic tank performing the nitriding reaction of the conventional wastewater treatment apparatus, since a large amount of oxygen is required for nitriding in order to completely extinguish ammonia, the amount of aeration from the diffuser is increased. In general, of the energy consumption used in the wastewater treatment apparatus, the most is energy consumption due to aeration in the aerobic tank. Therefore, as long as the wastewater treatment apparatus which requires complete nitriding is used, the aeration amount increases, and energy consumption inevitably increases.

In addition, in the case where a comprehensive immobilization carrier is used for the nitriding reaction, in order to realize complete nitriding, the amount of the comprehensive immobilization support is inevitably increased.

Regarding ammonia, there is a region in which a standard is set for acknowledging partial nitriding of ammonia which may remain up to a predetermined amount. However, the conventional wastewater treatment apparatus which requires complete nitriding cannot control to leave a certain amount of ammonia in an aerobic tank, so that if the air amount is sufficient, the nitriding reaction is difficult to progress to a nitriding instability state if it is insufficient. Becomes Therefore, the operation management of nitriding treatment cannot be performed and it does not fully respond to the wastewater treatment of partial nitriding. Although monitoring the ammonia concentration of the treated water and controlling the amount of aeration air flow is performed at the laboratory level, it is not practical to control the trace amount in the actual plant. That is, a wastewater treatment apparatus capable of realizing energy saving on the premise of partial nitriding of ammonia has not been developed until now.

The wastewater treatment apparatus 10 of this embodiment determines the quantity of wastewater to be delivered to the first anoxic tank 24 and the second anoxic tank 28 from the allowable values of ammonia contained in the treated water. By means of the distribution means 22 of the distribution line 20, part of the wastewater from the initial settling basin 50 is distributed to the first anoxic tank 24, and the remainder of the wastewater is distributed to the second anoxic tank 28.

It is preferable that the distribution means 22 have a quantity adjustment function. As means for realizing the water quantity adjustment function, for example, a dam, a distribution tank, or the like can be applied.

The wastewater returned to the first anaerobic tank 24 is sent to the aerobic tank 26, and the ammonia nitrogen in the wastewater in the aerobic tank 26 is completely nitrified. However, this is part of the wastewater returned from the initial settling basin 50. Therefore, the aeration amount of the aerobic tank 26 and the quantity of the comprehensive fixation support | carrier 38 can be reduced compared with the case where the ammonia nitrogen in all wastewater is fully nitrided.

The ammonia nitrogen in the wastewater returned to the second oxygen-free tank 28 is not nitrified. The wastewater subjected to nitrification and denitrification by the first anoxic tank 24 and the aerobic tank 26 and the wastewater containing ammonia nitrogen are mixed. Finally, the mixed liquid is discharged from the second anoxic tank 28 as treated water. Since the treated water contains ammoniacal nitrogen, the wastewater is partially nitrified. According to the wastewater treatment apparatus 10 of the present embodiment, energy saving can be realized while partially nitriding by reducing the aeration amount of the aerobic tank 26.

Next, the method of determining the quantity of wastewater to be sent to the first anoxic tank 24 and the second anoxic tank 28 will be described.

FIG. 2 shows a flow diagram of the wastewater treatment apparatus 10 of FIG. 1. The quantity Q of the wastewater (raw water) which flows into the wastewater treatment apparatus 10 is made into ammonia nitrogen = 30 mg / L, and the ammonia nitrogen of the treated water is set to 5 mg / L. If the ratios of the water flowing into the first anoxic tank 24 and the second anoxic tank 28 are A and B, respectively, the amount of wastewater Q = A · Q + B · Q becomes a relationship. For this reason, it becomes the quantity A * Q of the wastewater distributed to the 1st anoxic tank 24, and the quantity B * Q of the wastewater distributed to the 2nd anoxic tank 28, and the quantity of the treated water returned from the final sedimentation tank 60 is 0.75. Q Considering the amount of nitrogen in the wastewater, the following relationship is established. Here, it is considered that nitrogen is not added to the activated sludge.

In addition, the following relationship holds.

Substituting (2) into (1) gives the following equation.

By (3), B = 0.292 is found and A = 1-B = 0.708.

The yield ratio of A and B described above is calculated.

When the ratio of the total amount of waste water to be completely nitrided is determined, the amount of aeration in a reasonable aerobic tank is determined according to the amount, and energy saving can be realized.

In the above calculation result, the raw water quantity ratio to be fully nitrided is 0.708, and 30% can be reduced as oxygen required for the nitriding reaction, and there is a merit that the amount of aeration air can be greatly reduced.

3 is a schematic view showing a container 80 for storing the enclosing immobilization support 38. It is preferable that the encapsulation fixing support 38 is filled in the exhalation tank 26 in the state in which the water supply hole 81 was accommodated in the container 80 in which it was formed in multiple numbers. The size of the through hole 81 is such that the encapsulation fixing carrier 38 does not pass through. It is preferable that the container 80 is a spherical body having a diameter of 50 to 150 mm. The container 80 is integrated by screwing two hemispherical bodies 80A and 80B which divided | segmented the sphere into two by the fitting part or the screw groove in the division part 82. FIG.

The material of the container 80 is not specifically limited. Considering the ease of processing and the specific gravity which can flow in the aeration tank 26 by the aeration air from the diffuser 36, it is preferable that it is made of plastic. In the state where the encapsulation fixing support 38 is accommodated, it is preferable that the container 80 has a specific gravity of 0.98 to 1.02.

The encapsulating immobilization support 38 contained in the container 80 has a specific gravity of 0.98 to 1.02 close to water in consideration of fluidity. If the specific gravity of the encapsulating immobilization support 38 is smaller than this range, it will float to a liquid level. On the other hand, if the specific gravity of the encapsulating immobilization support 38 is larger than this range, it will settle to the bottom of the aerobic tank 26. In order to flow the encapsulation immobilization carrier 38, large aeration power is required. For this reason, the specific gravity of the container 80 was made the same.

In addition, it is preferable to make 30% of the volume in the container 80 the upper limit as a storage rate of the comprehensive fixation support | carrier 38 accommodated in the container 80. As shown in FIG. This is because if the storage rate exceeds 30%, the vigorous flow of the encapsulating immobilization carrier 38 in the container 80 is inhibited.

In the aeration tank 26, the container 80 flows by air aerated from the diffuser 36. In addition, the encapsulation immobilization carrier 38 flows in the vessel 80. By this double flow, the contact efficiency of the comprehensive fixation support | carrier 38 and wastewater can be improved. The nitriding treatment efficiency in the aerobic tank 26 can be improved.

When the encapsulation fixing carrier 38 is housed in the container 80, the scale width of the screen 40 can be increased as compared with the case where the encapsulation fixing carrier 38 is not stored in the container 80. Simplification of the screen 40, for example, it is possible to use a commercially available gold mesh, punching metal and the like. For example, when the container 80 has a diameter of 100 mm, if the container 80 does not flow out into the second anoxic tank 28 at the rear end, for example, a gold mesh having a hole of 50 to 80 mm angle or Punching metal can be used. As a result, the foreign matter adheres to the screen 40 and is not blocked. By using the container 80, the maintenance frequency can be reduced, and operation management can be facilitated. In addition, since air aeration for preventing screen clogging becomes unnecessary, it leads to reduction of aeration power.

Here, the encapsulation immobilization support 38 will be described.

The encapsulation immobilization support 38 in this embodiment superposes | immobilizes microorganisms in the immobilization material by superposing | polymerizing the immobilization material which mixed the microorganism containing nitride bacteria, and has a particle diameter of about 1-5 mm (typically 3 mm). Is used. Examples of the immobilization material include polymer monomers, prepolymers, oligomers, and the like, but are not particularly limited, and examples thereof include polyacrylamide, polyvinyl alcohol, polyethylene glycol, sodium alginate, carrageenan, and agar. In addition, the following can be used for the prepolymer of an immobilization material.

(Monomethacrylates) polyethylene glycol monomethacrylate, polypren glycol monomethacrylate, polypropylene glycol monomethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methacryloyl Oxyethylhydrogenphthalate, methacryloyloxyethylhydrogensuccinate, 3-chloro-2-hydroxypropyl methacrylate, stearyl methacrylate, 2-hydroxy methacrylate, ethyl methacrylate and the like.

(Monoacrylates) 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobor Nyl acrylate, cyclohexyl acrylate, methoxy triethylene glycol acrylate, 2-ethoxy ethyl acrylate, tetrahydrofurfuryl acrylate, phenoxy ethyl acrylate, nonyl phenoxy polyethylene glycol acrylate, nonyl phenoxy poly Propylene glycol acrylate, silicone modified acrylate, polypropylene glycol monoacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, methoxy polyethylene glycol acrylate, acryloyloxyethyl hydride Rosen succinate, lauryl acrylate Etc.

(Dimethacrylates) 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacryl Latex, polyethylene glycol dimethacrylate, butylene glycol dimethacrylate, hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypren glycol dimethacrylate, 2-hydroxy-1,3-di Methacryloxypropane, 2,2-bis-4-methacryloxyethoxyphenylpropane, 3,2-bis-4-methacryloxydiethoxyphenylpropane, 2,2-bis-4-methacryloxypolye Oxyphenyl propane and the like.

(Diacrylates) ethoxylated neopentyl glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate 2,2-bis-4-acryloxydiethoxyphenyl propane, 2-hydroxy-1-acryloxy-3-methacryloxypropane, and the like.

(Trimethacrylates) Trimethylolpropane trimethacrylate and the like.

(Triacrylates) Trimethylol propane triacrylate, pentaerythritol triacrylate, trimethylol propane EO addition triacrylate, glycerin PO addition triacrylate, ethoxylated trimethylol propane triacrylate, and the like.

(Tetraacrylates) Pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, ditrimethylol propane tetraacrylate, and the like.

(Urethane acrylates) Urethane acrylate, urethane dimethyl acrylate, urethane trimethyl acrylate and the like.

(Others) acrylamide, acrylic acid, dimethylacrylamide.

Moreover, although the radical polymerization using potassium persulfate is the most suitable for superposition | polymerization in this invention, superposition | polymerization and redox polymerization using an ultraviolet-ray or an electron beam may be sufficient. In the polymerization using potassium persulfate, the amount of potassium persulfate added is preferably 0.001 to 0.25%, and 0.001 to 0.5% of an amine polymerization accelerator may be added. As an amine polymerization promoter, (beta) dimethylamino propionitrile, NNN'N 'tetramethylethylene diamine, etc. are preferable.

In addition, the nitride bacteria to be comprehensively immobilized in the immobilization material may be purely cultured, but it is more preferable to comprehensively immobilize activated sludge containing the nitride bacteria. This is because the oxygen dissolved in the immobilization material inhibits the polymerization, but by comprehensively immobilizing the activated sludge, the activated sludge consumes oxygen and proceeds the polymerization reaction smoothly, so that a strong and broadly immobilized carrier 38 is obtained. Can be.

4 is a schematic configuration diagram showing the wastewater treatment apparatus 12 according to the second embodiment. The same code | symbol is attached | subjected to the structure similar to the wastewater treatment apparatus 10 of 1st Embodiment, and description is abbreviate | omitted.

The wastewater treatment apparatus 12 includes an aeration tank 44 provided at the rear end of the second anaerobic tank 28. An diffuser 46 is installed at the bottom of the aeration tank 44. The diffuser 46 communicates with a blower not shown. Air sent from the blower is aerated in the aeration tank 44 from the diffuser 46. By aeration of the treated water discharged from the second anaerobic tank 28 in the aeration tank 44, the properties of the activated sludge can be improved. If the activated sludge in the treated water is sent to the final sedimentation basin 60 without aeration, the phenomenon that the activated sludge does not precipitate occurs. On the other hand, aeration of the activated sludge in the treated water improves the properties of the activated sludge, and it is possible to settle the activated sludge in the final settling basin 60. As a result, the activated sludge can be easily returned from the final settling basin 60 to the first oxygen-free tank 24.

In addition, by aeration of the treated water in the aeration tank 44, the organic components included in the treated water can be decomposed. This can prevent the treated water from becoming cloudy.

In addition, the time for allowing the treated water to stay in the aeration tank 44 is short, for example, 30 minutes to 90 minutes, and no substantial nitriding reaction is performed.

FIG. 5: is a schematic block diagram which shows the wastewater treatment apparatus 14 which concerns on 3rd Embodiment. The same code | symbol is attached | subjected to the structure similar to the wastewater treatment apparatus 10 of 1st Embodiment, and description is abbreviate | omitted.

The wastewater treatment apparatus 14 further includes a sensor 90 for measuring the ammonia concentration of the treated water discharged from the second anoxic tank 28, and a quantity control means 92 electrically connected to the sensor 90. . In addition, in this embodiment, the distribution means 22 with a quantity adjustment function is used. The quantity control means 92 is electrically connected to the distribution means 22. The quantity control means 92 controls the quantity adjustment function of the distribution means 22 based on the measurement result from the sensor 90.

The ammonia concentration of the treated water is measured, and the amount of wastewater distributed to the first anoxic tank 24 and the second anoxic tank 28 is adjusted based on the measurement result.

For example, even when the ammonia concentration in the wastewater flowing into the wastewater treatment apparatus 14 is changed, since the ammonia concentration of the treated water is observed and the amount of water is adjusted, it is possible to suppress the ammonia concentration of the treated water within a specified value. Done.

Moreover, the sensor 90 and the quantity control means 92 provided in the wastewater treatment apparatus 14 which concerns on 3rd Embodiment can also be applied to the wastewater treatment apparatus 12 which concerns on 2nd Embodiment.

10, 12, 14... Wastewater treatment apparatus 20. Distribution line
22... Distribution means 24... First anaerobic tank
26... Aerobic tank 28... Second anaerobic tank
30 ... Circular line 32... motor
34... Stirring blades 36, 46... Diffuser
38 ... Inclusive immobilization carrier 40... screen
42 ... Pump 44.. Aeration tank
50... Initial settling basin 60.. Final sedimentation basin
62 ... Conveying line 80... Vessel
90... Concentration sensor 92... Quantity control means

Claims (6)

A wastewater treatment apparatus for removing nitrogen by partially nitriding ammonia nitrogen in organic wastewater,
An aerobic tank for nitriding the ammonia in the wastewater with nitrifying bacteria to produce nitriding water,
A first oxygen-free tank installed at the front end of the aerobic tank, wherein a part of the nitriding water is returned from the aerobic tank, and the nitriding water is denitrified by denitrification bacteria;
A second anoxic tank installed at a rear end of the aerobic tank, wherein a part of the nitriding water is fed from the aerobic tank and denitrified by the denitrifying bacterium, and is sent to the rear stage as treated water;
A distribution line for distributing the wastewater to the first anoxic tank and the second anoxic tank;
The wastewater treatment apparatus provided in the said distribution line and provided with distribution means which distributes the said wastewater to a said 1st anoxic tank and a said 2nd anoxic tank. The method of claim 1,
The said distribution means is a wastewater treatment apparatus which has a quantity adjustment function which adjusts a quantity of water. The method according to claim 1 or 2,
The nitride bacteria wastewater treatment apparatus that is comprehensively fixed to the comprehensive immobilization carrier. The method of claim 1,
The wastewater treatment apparatus provided in the rear end of a said 2nd anoxic tank, and further provided with the aeration tank for improving the property of the sludge in the said treated water, and decomposing the organic component in the said treated water. The method according to claim 2 or 4,
And waste water treatment means for controlling a distribution means having a water quantity adjustment function based on the measurement means for measuring the ammonia concentration in the treated water and the measurement result of the measurement means. The method of claim 3,
The wastewater treatment apparatus filled with the exhalation tank in which the encapsulation-immobilized carrier is flowably housed in a container in which a plurality of water passages of a size through which the encapsulation-immobilized carrier does not pass are formed.

Images