TWI646059B - Discharge water treatment method and discharge water treatment device - Google Patents

Abstract

A drainage water treatment method uses a semi-batch type biological treatment tank 10 in which a drainage water inlet 22 is disposed at a position lower than the treatment water outlet 24 and a biological sludge is contained in the tank to biologically treat the discharged water. The method for treating the discharged water includes: Biological treatment step: when the introduction of the above-mentioned discharged water from the discharged water inlet 22 and the discharged of the treated water from the treated water outlet 24 are stopped, the discharge in the stirred semi-batch biological treatment tank 10 is stopped. Water, using the aforementioned biological sludge for biological treatment of the aforementioned discharged water; and introduction of the discharged water. Process water discharge step: from the time when the stirring of the discharged water in the semi-batch type biological treatment tank 10 is stopped, until the sludge layer of the aforementioned biological sludge is formed in the semi-batch type biological treatment tank 10, the inlet of the discharged water is started. The aforementioned drainage water of 22 is introduced, and the aforementioned drainage of the treated water from the treated water outlet 24 is started. The method for treating discharged water is to introduce the aforementioned biological treatment steps and the aforementioned discharged water. Discharge water treatment method in which the treatment water discharge step is sequentially repeated.

Description

Drained water treatment method and device

The present invention relates to a technology of a drainage water treatment method and a drainage water treatment device for biologically treating drainage water containing organic matter and the like.

Conventionally, in the biological treatment of the discharged water, an activated sludge method using an aggregate of microorganisms (aerobic biological sludge) called "clotting" has been used. However, in the activated sludge method, when the "clot" (aerobic biological sludge) is separated from water in the sedimentation tank, the sedimentation rate of the "clot" is slow, so it is sometimes necessary to set the surface area of the sedimentation tank. Into very big. In addition, the treatment speed of the activated sludge method depends on the sludge concentration in the biological treatment tank. Although the treatment speed can be increased by increasing the sludge concentration, if the sludge concentration is increased to 1500 to 5000 mg / L In the range or higher, sludge separation obstacles such as surging may occur, and the treatment cannot be maintained.

On the other hand, in the anaerobic biological treatment, microorganisms called "particles" are generally used to densely aggregate into granular aggregates (anaerobic biological sludge). The settling speed of "particles" is very fast. Due to the densely packed state of microorganisms, the concentration of sludge in the biological treatment tank can be increased, and high-speed treatment of discharged water can be realized. However, compared with aerobic treatment (activated sludge method), anaerobic biological treatment may have problems in that the type of discharged water to be treated is limited, or the temperature of the treated water must be maintained at 30 to 35 ° C. In addition, if the anaerobic biological treatment is used alone, the quality of the treated water may not be good. When it is discharged to rivers and the like, it may be necessary to perform aerobic treatment such as a living sludge method.

In recent years, I have learned that by using a semi-batch processing device that intermittently flows the discharged water into the reaction tank for processing, the way to further shorten the sedimentation time of biological sludge is not limited to anaerobic biological sludge, that is, Even aerobic biological sludge can form granulated biological sludge with good sedimentability (for example, refer to Patent Documents 1 to 4). By granulating the biological sludge, the average particle diameter can be 0.2 mm or more and the sedimentation speed can be 5 m / h or more. Moreover, in a semi-batch type processing device, (1) introduction of discharged water, (2) biological treatment of a treatment target substance, (3) sedimentation of biological sludge, and (4) treatment water can be used in one biological treatment tank The discharge is processed in four steps. By forming the granulated biological sludge with good sedimentability as described above, the sludge concentration in the tank can be maintained at a high concentration, and high-speed processing can be achieved. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2004/024638 [Patent Document 2] Japanese Patent Laid-Open No. 2008-212878 [Patent Document 3] Japanese Patent No. 4975541 [Patent Document 4] Japanese Patent No. 4804888

[Problems to be solved by the invention]

The above-mentioned (3) biological sludge sedimentation system undergoes (i) re-clotting, (ii) regional sedimentation, (iii) migration, and (iv) compaction. During the migration process, the density of sedimentation sludge increases. Interference between sludge particles becomes stronger. Next, in the final stage of sedimentation, that is, in the compaction process, compaction of the settled sludge is performed. A sludge layer with a high sludge concentration is formed during migration and compaction.

The sludge layer formed during the migration and compaction process is not only composed of biological sludge with large particle size, but also many biological sludge with low sedimentation and small particle size. In a state where the biological sludge having a small particle size is carried into the sludge layer in this manner, it is difficult to selectively discharge the biological sludge having a small particle size out of the biological treatment tank. However, in a state where a large amount of small-size biological sludge remains in the biological treatment tank, even if a semi-batch biological treatment is performed, it is not easy to obtain biological sludge with a high sedimentation property, or until a biological sediment with a high sedimentation property is obtained. It must take a lot of time until the mud. As a result, it takes a lot of time to start the biological treatment, which makes it difficult to treat the discharged water at high speed. In addition, in any of the above-mentioned patent documents 1 to 4, in the sedimentation step, a sludge layer with a small size of biological sludge is formed, and then a treatment water discharge step is performed.

Therefore, an object of the present invention is to provide a drainage water treatment method and a drainage water treatment device that can obtain biological sludge with high sedimentability, and further can obtain biological sludge with high sedimentation in a short time. [Solution to the problem]

(1) A method for treating discharged water, comprising a semi-batch biological treatment step for biologically treating the discharged water using a semi-batch biological treatment tank containing biological sludge, characterized in that the semi-batch biological treatment step includes: biological In the processing step, when the introduction of the discharged water to the semi-batch biological treatment tank and the discharge of the treated water from the semi-batch biological treatment tank are stopped, the discharged water in the semi-batch biological treatment tank is stirred. Using the biological sludge for biological treatment of the discharged water; and introduction of the discharged water. The treatment water discharge step starts from stopping the stirring of the discharged water in the semi-batch type biological treatment tank, and until the sludge layer of the biological sludge is formed in the semi-batch type biological treatment tank, the half-batch is started. The biological water treatment tank introduces the discharged water, and starts to discharge the treated water from the semi-batch biological treatment tank; and the discharged water treatment method repeats the biological treatment step and the drainage water introduction sequentially. Process water discharge step.

(2) The method for treating discharged water as described in (1) above, wherein the discharged water is introduced. In the treatment water discharge step, at the same time as the discharge water in the semi-batch biological treatment tank is stirred or stopped immediately, the introduction of the discharged water to the semi-batch biological treatment tank is started, and the semi-batch biological treatment tank is started. The treated water is discharged from the treatment tank.

(3) The method for treating discharged water as described in (1) or (2) above, further comprising: a continuous biological treatment step: biologically treating the discharged water continuously flowing into the continuous biological treatment tank containing the biological sludge, and Biological sludge supply step: supplying particles formed in the semi-batch biological treatment step to the continuous biological treatment tank, and treated water supply step: supplying the treated water discharged from the semi-batch biological treatment step to the Continuous biological treatment tank and discharge water flow adjustment step: the supply of the particles accompanying the use of the biological sludge supply step, and the supply of the treated water using the treatment water supply step reduce the flow into the continuous biological treatment tank The flow of the discharged water.

(4) The method for treating discharged water according to the above (3), wherein in the adjusting step of the discharged water flow rate, the supply of the particles accompanying the use of the biological sludge supply step, and the treatment of water using the treatment water supply process The supply is to zero the flow rate of the discharged water flowing into the continuous biological treatment tank.

(5) The method for treating discharged water according to any one of (1) to (4) above, wherein the semi-batch biological treatment tank is provided with: a discharge water inflow inlet: in order to discharge the discharged water into the semi-batch biological treatment Tank and sludge treatment water outlet: disposed at a position higher than the discharge water inlet, a treatment water outlet for discharging the treatment water outside the tank or for discharging the treatment water and the particles outside the tank.

(6) A drainage water treatment device, comprising: a semi-batch biological treatment tank: containing biological sludge in the tank, and introduction means: introducing drainage water into the semi-batch biological treatment tank, and discharging means: The treated water in the semi-batch biological treatment tank is discharged out of the tank, and the stirring means: agitates the discharged water in the semi-batch biological treatment tank, and the first control means: controls the operation of the stirring means, and the second control means : Controlling the operation of the introduction means and the discharge means; wherein the first control means is the introduction of the discharged water into the semi-batch biological treatment tank when the discharged water is biologically treated using the biological sludge, and When the discharge of the treated water from the semi-batch biological treatment tank is stopped, the stirring means is operated to stir the discharged water in the biological treatment tank; wherein the second control means is to stop the stirring means The agitated discharged water is stirred until the sludge layer of the biological sludge is formed in the biological treatment tank, the introduction means is operated, and the drainage of the semi-batch biological treatment tank is started. Introduction and operation of the discharge means, the discharge started by the processing of the semi-batch processor biological water.

(7) The drainage water treatment device according to the above (6), wherein the second control means uses the introduction means to operate at the same time as or immediately after stopping the stirring of the discharged water by the stirring means, and starts the The drainage water of the semi-batch biological treatment tank is introduced, the drainage means is operated, and the treatment water from the semi-batch biological treatment tank is started to be discharged.

(8) The drainage water treatment device according to the above (6) or (7), wherein the second control means is capable of making the amount of the drainage water introduced into the semi-batch biological treatment tank and the semi-batch biological treatment discharged The introduction means and the discharge means are operated in the same manner as the amount of treated water in the tank.

(9) The drainage water treatment device according to any one of (6) to (8), wherein the semi-batch type biological treatment tank is provided with a drainage water inlet for injecting the drainage water into the tank, and for treating the wastewater The water is discharged from the treated water outlet outside the tank; the discharged water inlet is disposed at a position lower than the treated water outlet.

(10) The discharged water treatment device according to the above (9), wherein the treated water outflow port is provided at a water surface height of the discharged water in the semi-batch type biological treatment tank when the discharge of the treated water is stopped.

(11) The discharge water treatment device according to any one of (6) to (10) above, further comprising: a continuous biological treatment device: biologically treating the continuously discharged wastewater, and a biological sludge supply means: The granules formed by the semi-batch type biological treatment device are supplied to the continuous type biological treatment device, and the processing water supply means: supply the treated water discharged from the half-type biological treatment device to the continuous type biological treatment device, and the discharged water Flow adjustment means: adjusting the flow rate of the discharged water flowing into the continuous biological treatment device; wherein the discharge water flow adjustment means is accompanied by the supply of the particles using the biological sludge supply means, and the treatment water supply means using the The supply of treated water reduces the flow rate of the discharged water flowing into the continuous biological treatment device.

(12) The discharged water treatment device according to the above (11), wherein the discharged water flow adjustment means is accompanied by the supply of the pellets by the biological sludge supply means and the supply of the treated water by the treated water supply means, and will flow into The flow rate of the discharged water of the continuous biological treatment device is reset to zero.

(13) The drainage water treatment device according to any one of (6) to (8) above, wherein the semi-batch type biological treatment device includes: a drainage water inlet: in order to flow the drainage water into the tank, and a treatment water outlet : Set at a position higher than the discharge water inlet, in order to discharge the treated water outside the tank, or the sludge treatment water outlet: In order to discharge the treated water and the particles outside the tank. [Effect of the invention]

According to the present invention, it is possible to provide a drainage water treatment method and a drainage water treatment device that can obtain biological sludge with high sedimentability, and further can obtain biological sludge with high sedimentation in a short time.

Hereinafter, embodiments of the present invention will be described. In addition, this embodiment is an example of implementing the present invention, and the present invention is not limited to this embodiment.

FIG. 1 is a schematic diagram showing an example of the configuration of a semi-batch type biological treatment apparatus related to the embodiment. As shown in FIG. 1, the semi-batch type biological treatment apparatus 1 includes a semi-batch type biological treatment tank 10, a discharged water introduction device 12, a distributor 14, a treated water discharge device 16, a stirring system, and a control device 20.

The semi-batch biological treatment tank 10 of this embodiment is a biological sludge in a storage tank, and uses the biological sludge to treat the discharged water. The semi-batch type biological treatment tank 10 according to this embodiment includes a discharge water inlet 22 for introducing discharged water, and a treatment water outlet 24 for discharging treated water. The discharge water inlet 22 is disposed at a position lower than the treatment water outlet 24.

The drain water introduction device 12 according to this embodiment includes a drain water introduction pipe 26, a drain water pump 28, and a drain water side solenoid valve 30. The drain water introduction pipe 26 is connected to the drain water inlet 22 from the outside of the semi-batch type biological treatment tank 10. A drain water pump 28 and a drain water solenoid valve 30 are provided in the drain water introduction pipe 26. The drain water pump 28 and the drain water solenoid valve 30 are electrically connected to the control device 20. The discharged water introduction device 12 may be a device for introducing the discharged water into the semi-batch type biological treatment tank 10 from the discharged water inlet 22, and is not limited to the above structure. For example, the discharged water introduction pipe 26, Water pump 28 and other components. Moreover, in this embodiment, the distributor 14 is installed in the semi-batch type biological treatment tank 10, and is connected to the drain water inlet 22 from the inside of the semi-batch type biological treatment tank 10. That is, the drain water introduction pipe 26 and the dispenser 14 are communicated through the drain water inlet 22.

The treated water discharge device 16 according to this embodiment includes a treated water discharge pipe 32 and a treated water side solenoid valve 34. The treated water discharge pipe 32 is connected to the treated water outflow port 24 from the outside of the semi-batch type biological treatment tank 10. The treated water discharge pipe 32 is provided with a treated water-side solenoid valve 34. The treated water-side solenoid valve 34 is electrically connected to the control device 20. The treatment water discharge device 16 may be a device configured to discharge the treatment water in the semi-batch type biological treatment tank 10 through the treatment water outlet 24, and is not limited to the above configuration. For example, the treatment water discharge pipe 32 may be used. , Treated water pump, treated water side solenoid valve 34 and the like.

The stirring system of this embodiment includes a stirring device 36 and an aeration device 38. The stirring device 36 according to this embodiment includes a motor 40, a stirring blade 42, and the like, and agitates the discharged water in the semi-batch type biological treatment tank 10 by using the stirring blade 42 that rotates in accordance with the rotation of the motor 40. The aeration device 38 according to this embodiment includes an air diffusion pump 44, an air diffusion tube 46, and the like. The air diffusion pump 44 sends an aeration gas such as oxygen or air to the air diffusion tube 46. The aeration gas is supplied into the semi-batch type biological treatment tank 10, and thereby the discharged water in the semi-batch type biological treatment tank 10 is flow-stirred. The motor 40 and the air diffusion pump 44 are electrically connected to the control device 20.

FIG. 2 is a schematic diagram showing another example of the configuration of the semi-batch type biological processing apparatus according to the embodiment. The stirring system is not limited to the above structure as long as it has a system structure capable of stirring the discharged water in the semi-batch type biological treatment tank 10. For example, in aerobic biological treatment, as in the semi-batch type biological treatment device 2 shown in FIG. 2, since the stirring device 36 and the like are not required, the stirring system can also be constituted by an aeration device 38. Aeration gas is supplied, and the water is stirred and discharged in a state where the aerobic conditions in the semi-batch type biological treatment tank 10 are made. In addition, for example, in the anaerobic biological treatment, since an aeration device 38 or the like is not required, the stirring system may be constituted by the stirring device 36, and the discharged water may be stirred by the stirring device 36.

The control device 20 is composed of a CPU that performs calculations on a program, a microcomputer and an electronic circuit composed of a ROM and a RAM that stores programs or calculation results, and is used as a first control device that controls the operation of the stirring device 36 and the aeration device 38 and A second control device that controls the operation of the discharged water introduction device 12 and the treated water discharge device 16. In this embodiment, an example is shown in which the first control device and the second control device are implemented in one control device, but it is not limited to the above configuration, and the first control device and the second control device may be individually implemented. Control device.

An example of the operation of the semi-batch type biological processing apparatus 1 according to this embodiment will be described.

With the control device 20, the discharge water side solenoid valve 30 is opened, the discharge water pump 28 is operated, and the discharge water is introduced into the semi-batch type biological treatment tank 10 through the discharge water inlet pipe 26 and the discharge water inlet 22. In addition, in this embodiment, in order to make the inflow linear velocity of the discharged water uniform, the discharged water is supplied from a distributor 14 provided in the semi-batch type biological treatment tank 10.

After the control device 20 closes the discharge water side solenoid valve 30 and stops the operation of the discharge water pump 28, the motor 40 and the air diffusion pump 44 are operated. Thereby, the agitating blade 42 is rotated, the aeration gas is supplied into the semi-batch type biological treatment tank 10 from the air diffusion pipe 46, and the discharged water and biological sludge in the semi-batch type biological treatment tank 10 are stirred. Next, in the semi-batch type biological treatment tank 10, the discharged water is biologically treated with biological sludge to decompose the substance to be treated in the discharged water (biological treatment step).

After the biological treatment is performed for a predetermined time while stirring the discharged water, the operation of the motor 40 and the air diffusion pump 44 is stopped by the control device 20. That is, stirring of the discharged water in the semi-batch type biological treatment tank 10 is stopped. Once the agitation of the discharged water is stopped, the biological sludge begins to settle. Here, if the sedimentation of the biological sludge continues to progress, a sludge layer of the biological sludge will be formed in the semi-batch biological treatment tank 10.

In this embodiment, the control device 20 is used to operate the discharge water pump 28 and the discharge water side solenoid valve 30 is opened from the time when the stirring of the discharge water is stopped until the sludge layer of the biological sludge is formed; The discharge water inlet 22 starts the introduction of the discharge water, opens the treated water side solenoid valve 34, and starts the treatment water discharge from the treatment water outlet 24 (the discharge water introduction and treatment water discharge step). In this way, the discharge water is introduced from the discharge water inlet 22 located at a position lower than the treated water outlet 24, and the treated water is discharged from the treatment water outlet 24 located at a position higher than the discharge water inlet 22, thereby reducing the particle size. The biological sludge or biological sludge whose sedimentation speed is slower than the inflow linear velocity (m / h) of the discharged water introduced into the semi-batch biological treatment tank 10 is discharged out of the system together with the treated water. In contrast, after the sludge layer of biological sludge is formed in the semi-batch type biological treatment tank 10, even if the drainage water is introduced from the drainage water inlet 22 located at a position lower than the treatment water outlet 24, The treatment water discharged from the treatment water outlet 24 at a high position of the inlet 22 is discharged into the sludge layer because the biological sludge with a small particle size is carried into the sludge layer, so it is difficult to discharge the biological sludge with a small particle size together with the treated water. . However, before the formation of the sludge layer of the biological sludge, it can be considered that the biological sludge with a small particle size mainly floats near the water surface. Therefore, the above-mentioned drainage water introduction and treatment water discharge steps can be used to granulate The biological sludge with a small diameter is discharged together with the treated water. Moreover, regarding the sludge with small particle size floating near the lower part of the reaction tank when the agitation of the discharged water is stopped, it can be considered that the re-clotting of the sludge continues to progress until the sludge layer is formed by discharging the water The introduction of treated water and the discharge of treated water can selectively discharge the biological sludge to the outside of the semi-batch biological treatment tank. And by sequentially repeating the above biological treatment steps and introduction of discharged water. In the treatment water discharge step, in the semi-batch type biological treatment tank 10, because a large amount of biological sludge (biological sludge having a large particle size) with a high sedimentation speed is selectively retained, biological sludge having a high sedimentation property can be obtained. In addition, since the introduction of the discharged water is performed together with the discharge of the treated water, the time of the treatment cycle is also shortened.

The discharge water inlet 22 for introducing the discharged water into the semi-batch type biological treatment tank 10 is preferably provided at a position lower than the treated water flow outlet 24 for discharging the treated water in the half-batch biological treatment tank 10. The drainage water inlet 22 is preferably located from the bottom of the semi-batch biological treatment tank 10 to a half of the height of the water surface in the semi-batch biological treatment tank 10; the treatment water outlet 24 is preferably located at the semi-batch biological The position between 1/2 of the height of the water surface in the processing tank 10 and the top of the semi-batch type biological treatment tank 10 is more preferable. In addition, the height of the water surface in the semi-batch type biological treatment tank 10 is the drainage water introduction. The height of the water surface at the end of the treated water discharge step. like this. The drain water inlet 22 is set at a position from the bottom of the semi-batch biological treatment tank 10 to a half of the height of the water surface in the half-batch biological treatment tank 10; the process water outlet 24 is set at the semi-batch type The water surface height within the biological treatment tank 10 is from 1/2 to the top of the semi-batch biological treatment tank 10; because by increasing the interval between the two, the effect of the linear velocity of the inflow of the discharged water can reach a large amount of biological sewage Therefore, more biological sludge with a slow sedimentation rate can be discharged from the treated water outlet 24. Moreover, since the treated water outflow opening 24 is provided at the water surface height position in the semi-batch type biological treatment tank 10, it is possible to push the semi-batch type biologicals while discharging the water into the semi-batch type biological treatment tank 10. The treated water in the treatment tank 10 can keep the amount of water in the semi-batch type biological treatment tank 10 at a certain value.

As described above, from the viewpoint that sludge with a small particle size can be selectively discharged out of the semi-batch type biological treatment tank, it is preferable to set the discharge water inlet 22 at a position lower than the treatment water outlet 24, but it is necessary to form a sedimentation. High-performance biological sludge does not necessarily need to be limited by the above-mentioned configuration. For example, the discharge water inlet 22 may be provided at a position higher than the treatment water outlet 24, or they may be provided at the same position. In any case, from the time when the stirring of the discharged water is stopped until the sludge layer of the biological sludge is formed, the introduction of the discharged water and the discharge of the treated water are started, and the sludge having a small particle size is discharged. Outside the semi-batch type biological treatment tank, sludge with high sedimentability can be formed. Here, in a case where the height position of the drain water inlet 22 is set to be higher than the height position of the treated water outlet 24, in order to prevent a large amount of highly sedimentable biological sludge from being discharged out of the system, it is preferable to adjust the flow rate with a valve or a pump. To keep the amount of water in the semi-batch biological treatment tank 10 at a certain value.

In this embodiment, biological treatment steps and drainage water are introduced. The operating conditions of the discharged water treatment in which the treated water discharge step is repeatedly performed are, for example, when the BOD concentration of the discharged water is 100 to 1000 mg / L and the BOD load is 0.5 to 3.0 kg / m ³ / day, it is better to set the Import. The discharge time of the treated water is in the range of 15 to 120 minutes, the reaction time of the biological treatment is in the range of 60 to 400 minutes, and the total time of one cycle is in the range of 2.0 to 8.0 hours.

The details of each processing step are described below.

(Biological treatment step) The biological treatment reaction in the semi-batch biological treatment tank 10 may be any one of only anaerobic (anaerobic) conditions, only aerobic conditions, and anaerobic (anaerobic) -aerobic interactive operation. . However, from the viewpoint of increasing the growth rate of biological sludge and the viewpoint of increasing the rate of particle formation, biological treatment containing aerobic conditions is preferred.

The discharge water system applicable to the biological treatment of this embodiment type is, for example, discharge water from food processing plants, discharge water from chemical plants, discharge water from semiconductor factories, discharge water from machinery factories, sewage, urine, river water, etc. Discharge water containing biodegradable substances. Biodegradable substances include, for example, organic substances, nitrogen-containing substances such as ammonia nitrogen and nitrate nitrogen. For example, in a case where the discharged water containing organic matter is biologically treated, the organic matter in the discharged water is decomposed to carbon dioxide by contact with biological sludge (microorganism). In addition, for example, when the discharged water containing a nitrogen-containing substance is biologically treated, the nitrogen-containing substance in the discharged water is decomposed to nitrogen gas by contact with biological sludge (microorganism).

The sludge concentration of the biological sludge in the semi-batch biological treatment tank 10 in the biological treatment step is preferably operated at, for example, 3000 to 30,000 mg / L from the viewpoint of maintaining the sludge's soundness (sedimentation, activity, etc.). Range. From the viewpoint of maintaining the sludge's soundness (sedimentation and activity), the sludge load is preferably kept in the range of 0.05 to 0.60 kg-BOD / kg-MLSS / day, and kept at 0.1 to 0.5 kg-BOD / The range of kg-MLSS / day is better. When the sludge load becomes higher than the above range or when the sludge concentration becomes higher than the above range, the biological sludge is preferably extracted from the semi-batch type biological treatment tank 10.

The pH value in the semi-batch type biological treatment tank 10 is preferably set within a range suitable for general microorganisms, for example, it is preferably 6 to 9, and more preferably 6.5 to 7.5. When the pH value is outside the aforementioned range, it is preferable to add an acid or an alkali to control the pH value. The amount of dissolved oxygen (DO) in the semi-batch biological treatment tank 10 is preferably above 0.5 mg / L, especially above 1 mg / L under aerobic conditions.

(Discharge water introduction and treatment water discharge step) In the discharge water introduction and treatment water discharge step, the introduction of the discharge water is started from the discharge water inlet 22 after stopping the stirring of the discharge water and forming the sludge layer of the biological sludge. And the discharge of the treated water in the biological treatment reaction tank is started from the treated water outlet 24. Here, in this step, "initiating the introduction of the discharged water and starting the discharge of the treated water" does not mean only "the period from the time when the stirring of the discharged water is stopped to the time when the sludge layer of the biological sludge is formed. The case where the introduction of the discharged water and the start of the discharge of the treated water "includes" the case where the discharge of the treated water is started after the introduction of the discharged water is started and before the introduction of the discharged water is stopped ".

The so-called "until the sludge layer of the biological sludge is formed" means that the stirring of the discharged water is stopped until the (ii) regional sedimentation process in the sedimentation process of the biological sludge ends. In addition, as mentioned above, a sludge layer is formed after the (iii) migration process of the sedimentation process of biological sludge. Therefore, the time from the stop of the agitation of the discharged water to the end of the regional sedimentation process (hereinafter referred to as the end of the area sedimentation of the semi-batch biological treatment tank), that is, from the agitation of the discharged water to the stoppage of the biological sludge Time until formation. In the present embodiment, the region settlement end time of the semi-batch type biological treatment tank is obtained, for example, by the following method.

For example, take a 1L sample (drain water) into a graduated cylinder and slowly stir to make the MLSS homogeneous. Stop stirring, measure the volume (mL) of the settled sludge over 5, 10, 15, 20, 30, 45, and 60 minutes, and find the percentages relative to the 1L sample volume and draw a sedimentation curve. In addition, because the sedimentation curve changes depending on the sedimentability of the sludge, in the case of sludge with good sedimentability (for example, the sludge sedimentation index, that is, when the SV15 is 100 mL / g or less), it is preferable to stop the stirring of the measuring cylinder. After that, for example, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 10, 15, 20, and 30 minutes, the sediment sludge volume is measured at short intervals, and a settlement curve is drawn.

FIG. 3 is a diagram showing an example of a settlement curve. As shown in FIG. 3, at least inflection points A and B exist in the settlement curve. The time from the sedimentation time 0 to the initial inflection point A is the time from the stop of the stirring of the discharged water to (i) the end of the recoagulation process; from the sedimentation time 0 to the second The time until the inflection point B is the time from the agitation of the discharged water to the end of (ii) the settlement process in the area. In addition, the inflection point B in the settlement curve is followed by (iii) migration process and (iv) compaction process.

The time from the agitation of the discharged water obtained from the sedimentation curve to the end of the (ii) regional sedimentation process is the time measured with a graduated cylinder (hereinafter referred to as the regional sedimentation end time measured with a graduated cylinder). Therefore, the area settlement end time of the semi-batch type biological treatment tank can be obtained by multiplying the end time of the area settlement measured by the graduated cylinder by the ratio of the height of the actual semi-batch type biological treatment tank to the height of the graduated cylinder. The specific formula is as follows.

Ending time of area settlement of processing device = Ending time of area settlement measured by graduated cylinder × (height of semi-batch biological treatment tank / height of graduated cylinder)

In this embodiment, the introduction of the discharged water is started before the end of the area settlement of the semi-batch type biological treatment tank obtained by the above formula, and the discharged of the treated water is started.

In addition, for example, the ultrasonic sludge interface meter may be installed in the semi-batch type biological treatment tank 10, and the drainage water may flow into the regional settlement. Specifically, after the stirring of the discharged water is stopped, the change in the height of the sludge interface from the bottom of the reaction tank in the sedimentation step is recorded with an ultrasonic sludge interface meter, and the change in the height of the recorded sludge interface is plotted as The same settling curve as in Fig. 3 can be used to determine the end time of the settling of the semi-batch biological treatment tank.

At the time when the discharged water is introduced into the treated water discharge step, it is better that the stirring of the discharged water is stopped or immediately after the stopped, the introduction of the discharged water is started from the discharged water inlet 22 and the discharged of the treated water is started from the treated water outlet 24. In this way, although there may be more biological sludge flowing out of the treated water outlet 24, the cycle time can be further shortened. "Immediately after the stirring of the discharged water is stopped" means that within 1 minute after stopping the power to the stirring system (the stirring device 36 or the aeration device 38), it is preferably within 30 seconds. Therefore, within 1 minute after the stirring of the discharged water is stopped, the introduction of the discharged water and the start of the discharge of the treated water are performed simultaneously; or after the introduction of the discharged water is started, the discharge of the treated water is started until the introduction of the discharged water stops. With this method, sludge with a smaller particle size and slow sedimentation speed can be actively discharged out of the system, and the cycle time can be shortened.

The stoppage time of the introduction of the discharged water and the stoppage time of the treated water depend on the inflow amount of the discharged water, the inflow rate, and the like. However, after the sludge layer of the biological sludge is formed, the introduction of the discharged water and the treatment water can be stopped. However, once the sludge interface of the biological sludge is formed, the biological sludge with a small particle size or the biological sludge with a slow sedimentation rate is carried into the sludge layer, so it is difficult to handle the sludge with a small particle size. Water is drained out of the system together. Therefore, from the viewpoint of shortening the cycle time, it is better to transfer the discharged water and discharge the treated water (stop the introduction of the discharged water and discharge the treated water) during the period before the formation of the sludge layer of the biological sludge and transfer to the biological treatment step .

The discharge water inflow rate (the ratio of the inflow amount of the discharge water to the water volume in the semi-batch biological treatment tank 10 in one cycle) is preferably in the range of, for example, 10% to 100%. The granulation of biological sludge can be considered to be that the biological sludge is repeatedly subjected to a state where the concentration of the treatment target substance (such as the concentration of organic matter) is very high (a state of satiation immediately after the inflow of the discharged water) and the concentration of the treatment target substance (such as the organic matter) Concentration) caused by a very low state (starvation at the end of biological treatment). Therefore, from the viewpoint of forming particles, although the higher the inflow rate of the discharged water, the better, but on the other hand, the higher the inflow rate of the discharged water, the larger the capacity of the discharged water pump 28 becomes, and the more expensive it becomes. The discharge water inflow rate is preferably in the range of 20% to 80%.

The inflow linear velocity (the ratio of the flow rate to the cross-sectional area of the semi-batch biological treatment tank) of the discharged water depends on the sludge concentration and the like, but is preferably 1 to 10 m / h, for example. Compared with the case where the inflow linear velocity of the discharged water does not satisfy the above range, if the inflow linear velocity of the discharged water satisfies the range of 1 to 10 m / h, it is stored in the sludge in the semi-batch biological treatment tank 10, It is possible to maintain a biological sludge with a high sedimentation rate while discharging a biological sludge with a slow sedimentation rate.

The inflow linear velocity of the discharged water is preferably increased with the granulation of the sludge. That is, in the case where there is little biological sludge (for example, granulated biological sludge) having a rapid sedimentation speed in the semi-batch biological treatment tank 10, the sewage flows into the drainage water at a low inflow linear velocity, and the biological sludge with a rapid sedimentation speed Increasing the rate of sludge (such as granulated biological sludge) increases the inflow linear velocity. The control of the inflow linear velocity like this is preferably performed while measuring the average particle diameter of the biological sludge with a particle size distribution meter. Specifically, in a case where the average particle size of the biological sludge in the semi-batch biological treatment tank 10 is 0.05 mm or less, the inflow linear velocity is set to 1 to 2 m / h for water transfer, and then, as the biological sludge The increase of the average particle diameter of the mud increases the inflow linear velocity. After the average particle diameter becomes 0.2 mm or more (after granulation), the inflow linear velocity is preferably increased to 2 to 10 m / h. In addition, actually, the sedimentation speed of the biological sludge in the semi-batch type biological treatment tank 10 can be measured from the regional sedimentation speed, and the linear velocity of the discharged water can be increased in accordance with the increase of the sedimentation speed.

It is also possible to install a physicochemical treatment device such as a sedimentation tank, a pressurized flotation device, or a MBR (membrane bioreactor), a fluidized bed carrier method, and an activity at the rear stage of the semi-batch biological treatment tank 10 of the present embodiment. Other treatment equipment, such as biological treatment equipment such as the sludge method, will be introduced from the discharged water. The processed water discharged from the processed water discharge step is supplied to another processing device. As a result, the introduction of discharged water from other treatment devices was appropriately treated. The treated water discharged in the treated water discharge step suppresses deterioration of the quality of the final treated water.

In addition, for example, in the case of treating discharged water containing a substance that exhibits biodegradability, in the front stage of the semi-batch type biological treatment tank 10 of the present embodiment, flotation separation, agglomeration and pressure flotation equipment, and adsorption may be provided. The physicochemical treatment device, such as a water heater, Fenton treatment, and ozone treatment, supplies the above-mentioned discharged water to the physicochemical treatment device. By using a physicochemical treatment device, a substance that exhibits biodegradability can be converted into a substance that exhibits biodegradability in the discharged water. For example, when the oil and fat components often contained in the water discharged from food processing plants are supplied to the biological treatment device without physical and chemical treatment, the oil and fat components may adhere to the biological sludge, which may cause bad biological treatment. influences. Therefore, it is preferable to use the above-mentioned physicochemical processing device to remove the oil and fat components to a level of 150 mg / L or less measured by the n-hexane extraction concentration (Soxhlet extraction weight method), and then supply the semi-batch biological treatment tank. 10.

From the viewpoint of promoting the granulation of biological sludge, the addition of Fe ²⁺ , Fe ³⁺ and Ca to the discharged water in the semi-batch biological treatment tank 10 or the discharged water before being introduced into the semi-batch biological treatment tank 10 Ions of hydroxides such as ²⁺ and Mg ²⁺ are preferred. Usually, the discharged water contains fine particles that can become the core of the particles. The addition of the above ions can promote the formation of the core of the particles.

Hereinafter, the discharged water treatment of biological treatment by supplying the pellets formed by the semi-batch type biological treatment device described so far to the continuous biological treatment device and performing biological treatment will be described. The semi-batch type biological treatment device shown in FIGS. 4 to 9 below is a modification of the semi-batch type biological treatment device described so far. That is, it can be understood that the semi-batch type biological treatment device shown in FIG. 1 or FIG. 2 can be applied to the discharged water treatment device described below. In addition, in the following, regarding the foregoing, the biological treatment step and the drainage water introduction are sequentially repeated. Although the process of forming particles by treating the water discharge step is omitted due to repeated description, it is a matter of course that the following semi-batch type biological treatment apparatus can be appropriately performed as required. For example, in the following semi-batch type biological treatment device, if the particle formation is desired when the biological treatment is started (at the start of the device) or when the particle concentration in the tank is significantly reduced, it is preferable to repeat the aforementioned biological treatment in order. Steps and drainage water introduction. The treatment water discharge step replaces the half-batch biological treatment that is normally performed, and performs particle formation.

FIG. 4 is a schematic diagram showing an example of a configuration of a drain water treatment device according to the embodiment. The discharged water treatment device 3 shown in FIG. 4 includes a continuous biological treatment device 48, a semi-batch biological treatment device 50, a solid-liquid separation device 52, and a discharged water storage tank 54.

The discharged water treatment device 3 shown in FIG. 4 is provided with discharged water inflow pipes 56a, 56b, and 56c, treated water discharge pipes 58a and 58b, a sludge return pipe 60, a sludge discharge pipe 62, and a biological sludge supply pipe 64. The drain water treatment device 3 shown in FIG. 4 includes a first drain water inflow pump 66, a second drain water inflow pump 70, a treated water discharge pump 72, a sludge supply pump 74, and a sludge return pump. Pu 76. The first drainage water inflow pump 66 is installed in the drainage water inflow pipe 56a, the second drainage water inflow pump 70 is connected to the drainage water inflow pipe 56b, the sludge supply pump 74 is connected to the biological sludge supply pipe 64, and the sludge The return pump 76 is connected to the sludge return pipe 60. The sludge discharge pipe 62 is provided with a solenoid valve 78.

One end of the drain water inflow pipe 56 a is connected to the drain water inlet of the drain water storage tank 54, and the other end is connected to the drain water inlet of the continuous biological treatment device 48. One end of the drain water inflow pipe 56 b is connected to the drain water inlet of the drain water storage tank 54, and the other end is connected to the drain water inlet of the semi-batch type biological treatment device 50. One end of the drain water inflow pipe 56c is connected to the drain water outlet of the continuous biological treatment device 48, and the other end is connected to the drain water inlet of the solid-liquid separation device 52. The treated water discharge pipe 58 a is connected to a treated water outlet of the solid-liquid separation device 52. One end of the sludge return pipe 60 is connected to the sludge outlet of the solid-liquid separation device 52, and the other end is connected to the sludge inlet of the continuous biological treatment device 48. The sludge discharge pipe 62 is connected to the sludge return pipe 60. One end of the biological sludge supply pipe 64 is connected to the sludge outlet of the semi-batch type biological treatment apparatus 50, and the other end is connected to the sludge supply port of the biological treatment apparatus 48. One end of the treatment water discharge pipe 58 b is connected to the treatment water outlet of the semi-batch type biological treatment device 50, and the other end is connected to the treatment water inlet of the continuous type biological treatment device 48.

FIG. 5 is a schematic diagram showing an example of the configuration of a semi-batch type biological treatment apparatus used in the embodiment. The semi-batch type biological treatment apparatus 50 shown in FIG. 5 performs the following (1) inflow of discharged water, (2) biological treatment of a processing target substance such as organic matter, as described later, (3) sedimentation of biological sludge, (4 ) Treatment of 4 steps of treatment water discharge. The semi-batch type biological treatment device 50 shown in FIG. 5 is provided with a semi-batch type biological treatment tank 80, and a second discharge water inflow pump 70 and a treated water discharge pump are provided in and around the semi-batch biological treatment tank 80. 72. Stirring device 86, air pump 88, air diffusion device 90, and sludge supply pump 74. The air diffusion device 90 is connected to the air pump 88, and the air supplied from the air pump 88 is supplied into the tank through the air diffusion device 90. In addition, the stirring device 86 is configured using, for example, a motor, a stirring blade, and a transmission shaft connecting the motor and the stirring blade. The semi-batch type biological treatment device 50 is provided with a drain water inlet 50a, a processed water outlet 50b, and a sludge outlet 50c. The drain water inlet 50a is connected to a drain water inflow pipe 56b, and the processed water outlet is connected to a process water discharge pipe 58b and a sludge outlet. 50c is connected to a biological sludge supply pipe 64.

The discharge water inflow pipe 56b and the second discharge water inflow pump 70 shown in FIG. 5 function as a semi-batch-type discharge water supply device to intermittently supply the discharge water to the semi-batch biological treatment device 50. In this embodiment, the second discharge water flows into the pump 70 for operation. The intermittent supply of the discharged water is stopped. For example, a solenoid valve or the like may be provided in the discharged water inflow pipe 56b, and the intermittent supply of the discharged water may be performed by using a valve switch.

The biological sludge supply pipe 64 and the sludge supply pump 74 shown in FIG. 5 are used as a biological sludge supply device which supplies particles to the continuous biological treatment device 48. In addition, a solenoid valve or the like may be provided in the biological sludge supply pipe 64 as appropriate.

The treated water discharge pipe 58 b and the treated water discharge pump 72 shown in FIG. 5 are used as a treated water supply device that supplies the treated water to the continuous biological treatment device 48. In addition, a solenoid valve or the like may be provided in the treated water discharge pipe 58b as appropriate.

The drain water inflow pipe 56a and the first drain water inflow pump 66 shown in FIG. 4 are used as a drain water supply device that supplies the drain water to the continuous side of the continuous biological treatment device 48. In addition, the first discharged water inflow pump 66 of FIG. 4 includes a supply of pellets using the biological sludge supply device and a supply of treated water using the processing water supply device, and has a regulated supply to a continuous biological treatment device. The function of 48 discharge water flow. Specifically, the first discharge water inflow pump 66 is electrically connected to the treatment water discharge pump 72 and the sludge supply pump 74. When the treatment water discharge pump 72 or the sludge supply pump 74 operates, these The output signal is sent to the first discharge water inflow pump 66. At the stage when the first discharge water inflow pump 66 receives the output signal, the output of the first discharge water inflow pump 66 is reduced, and the flow rate of the discharge water is reduced to a predetermined level. the amount. Alternatively, at the stage when the first discharge water inflow pump 66 receives the output signal, the operation of the first discharge water inflow pump 66 is stopped to zero the flow of the discharge water (that is, the discharge water from the discharge water inflow pipe 56a is stopped). Of supply). In addition, when the operation of the treated water discharge pump 72 or the sludge supply pump 74 is stopped and the transmission of the output signal is stopped, the output power of the first discharged water flowing into the pump 66 is preferably returned to the original state and restored. Drain water flow.

The continuous biological treatment device 48 of this embodiment is an aerobic reaction tank that biologically treats the continuously flowing discharged water. Although the continuous biological treatment device 48 shown in FIG. 4 is not shown, it includes, for example, a stirring device, an air pump, an air diffusion device connected to the air pump, etc., and the liquid in the tank is stirred by the stirring device, and The air supplied from the air pump is supplied into the tank through an air diffusion device.

The solid-liquid separation device 52 according to this embodiment is a separation device for separating biological sludge-containing water into biological sludge and treated water. Examples include sedimentation separation, pressure flotation, filtration, and membrane separation. Separation device.

An example of the operation of the drain water treatment device 3 according to this embodiment will be described.

In the drain water storage tank 54 shown in FIG. 4, the drain water whose work is the processing target is stored. Examples of the discharged water system to be treated include food processing plant discharge water, chemical plant discharge water, semiconductor factory discharge water, machinery factory discharge water, sewage, feces, and river water. Moreover, biodegradable organic substances and the like are usually contained in the discharged water. Furthermore, in the case where the biodegradable organic matter is contained in the discharged water, it is preferable to remove it in advance by a physical and chemical treatment such as a flotation separation, an agglomeration pressure flotation device, and an adsorption device.

First, the first discharge water inflow pump 66 is operated, and the treatment target discharge water in the discharge water storage tank 54 is supplied to the continuous biological treatment device 48 through the discharge water inflow pipe 56a. The continuous biological treatment device 48 performs biological treatment using discharged water of biological sludge under aerobic conditions. The treated water processed by the continuous biological treatment device 48 is supplied to the solid-liquid separation device 52 from the discharged water inflow pipe 56c, and the biological sludge is separated from the treated water.

When the semi-batch type biological treatment device 50 is operated (the state in which the first drain water flows into the pump 66 is kept in operation), the second drain water is allowed to flow into the pump 70 and the drain water storage tank 54 is processed. The target discharged water is supplied to the semi-batch type biological processing apparatus 50 (semi-batch type biological processing tank 80 shown in FIG. 5) from the discharged water inflow pipe 56b ((1) inflow of discharged water). After the discharged water is introduced into the semi-batch type biological treatment tank 80 to a predetermined amount, the second discharged water is stopped from flowing into the pump 70. Next, the air pump 88 is operated, air is introduced from the air diffusion device 90, and air is supplied into the semi-batch type biological treatment tank 80, and the stirring device 86 is operated, and the semi-batch type biological treatment tank 80 is stirred Biological treatment of the discharged water ((2) biological treatment of the treatment target substance). Then, after a predetermined time has elapsed, the supply of air is stopped by stopping the operation of the air pump 88, and the biological treatment is terminated by stopping the stirring device 86. After the biological treatment is completed, the biological sludge sedimentation in the semi-batch biological treatment tank 80 is reduced for a predetermined time, and the biological sludge and the treated water are separated in the semi-batch biological treatment tank 80 ((3) sedimentation of biological sludge) . Then, the treatment water discharge pump 72 is operated, and the treatment water in the semi-batch type biological treatment tank 80 is discharged through the treatment water discharge pipe 58b ((4) discharge of the treatment water), and the treatment water discharge pipe 58b is supplied to the continuous type. Bioprocessor 48. Then, the steps (1) to (4) are repeated. Further, by repeating the steps (1) to (4), particles are formed in the semi-batch type biological treatment tank 80. However, for example, when the biological treatment is started (when the device is started) or when the particle concentration in the tank is significantly decreased, the aforementioned biological treatment steps and drainage water introduction may be repeated sequentially. The process water discharge step replaces the steps (1) to (4) above to perform particle formation.

(4) In the step of discharging the treated water, the output power of the first discharged water flowing into the pump 66 is reduced at a stage when the first discharged water flowing into the pump 66 receives the output signal during the operation of the treated water discharging pump 72. To reduce the inflow of the discharged water supplied to the continuous biological treatment device 48. Alternatively, the operation of the first discharged water inflow pump 66 is stopped, and the flow rate of the discharged water supplied to the continuous biological treatment device 48 is reset to zero. If the inflow amount of the discharged water supplied to the continuous biological treatment device 48 is not reduced, the treatment water is supplied from the semi-batch biological treatment device 50 (the half-batch biological treatment tank 80 shown in FIG. 5). The amount of water in the continuous biological treatment device 48 increases significantly, so the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48 also increases. As a result, the flow load on the solid-liquid separation device 52 increases instantaneously, so the biological sludge cannot be sufficiently separated in the solid-liquid separation device 52, and a large amount of biological sludge may flow out together with the treated water in some cases. However, in this embodiment, as described above, the supply of the treated water from the semi-batch type biological treatment tank 80 to the continuous biological treatment device 48 reduces the inflow of the discharged water supplied to the continuous biological treatment device 48. Since the amount of water may be reset to zero, an increase in the amount of water flowing into the continuous biological treatment device 48 can be suppressed. As a result, an increase in the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48 is suppressed, and an instantaneous increase in the flow load on the solid-liquid separation device 52 is suppressed. Therefore, the discharge with the treated water can be suppressed. Of biological sludge. In addition, it is better to stop the operation of the treated water discharge pump 72 after a predetermined time has elapsed, and to return to the output state of the first discharged water into the pump 66 to the original state when it is transferred to (1) the discharge water inflow step again. To restore the inflow of the discharged water to the continuous biological treatment device 48.

When supplying treated water to the continuous biological treatment device 48, from the viewpoint of suppressing an increase in the amount of water flowing into the continuous biological treatment device 48, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is preferably reduced. The flow rate of the treated water supplied by the biological treatment tank 80 is equal to or higher than the flow rate of the discharged water. For example, before the treated water is supplied from the semi-batch biological treatment tank 80, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is 100 L / h, and the flow rate of the treated water supplied from the semi-batch biological treatment tank 80 is 30. In the case of L / h, when the treated water is supplied to the continuous biological treatment device 48, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is preferably 70 L / h or less, more preferably 0 L / h. In addition, even if the operation of the first discharge water inflow pump is stopped, the flow rate of the discharge water supplied from the discharge water inflow pipe to the continuous biological treatment device 48 is reset to zero (even if the inflow of discharge water from the discharge water inflow pipe 56a is stopped), The treated water discharged from the semi-batch type biological treatment tank 80 is supplied to the continuous biological treatment device 48 through the treated water discharge pipe 56b, so that the continuous supply of the discharged water in the continuous biological treatment device 48 can be ensured.

In addition, by operating the sludge supply pump 74, the particles formed in the semi-batch type biological treatment tank 80 are supplied to the continuous biological treatment device 48 through the biological sludge supply pipe 64. In addition, the supply of particles from the semi-batch type biological treatment tank 80 may be performed in the (3) sedimentation step of the biological sludge, or may be performed in the (2) biological treatment step of the treatment target substance, or may be (4). ) The discharging step of the treated water is performed. In any case, with the supply of particles to the continuous biological treatment device 48, that is, at a stage where the first discharge water inflow pump 66 receives the output signal of the sludge supply pump 74, the first discharge water flows into the pump 66 output. Alternatively, the operation of the first discharge water flowing into the pump 66 is stopped, and the flow rate of the discharge water supplied to the continuous biological treatment device 48 is reset to zero. This suppresses an increase in the amount of water flowing into the continuous biological treatment device 48. As a result, an increase in the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48 is suppressed, and an instantaneous increase in the flow load on the solid-liquid separation device 52 is suppressed, so that it can be suppressed together with the treated water. Amount of biological sludge discharged.

When supplying granular sludge to the continuous biological treatment device 48, from the viewpoint of suppressing an increase in the amount of water flowing into the continuous biological treatment device 48, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is reduced, so that It is preferable that the flow rate of the particles supplied from the type biological treatment tank 80 is equal to or higher than “the flow rate of the discharged water”. For example, before the pellets are supplied from the semi-batch biological treatment tank 80, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is 100 L / h, and the pellets supplied from the semi-batch biological treatment tank 80 are 10 L. In the case of / h, when supplying particles to the continuous biological treatment device 48, the flow rate of the discharged water supplied to the continuous biological treatment device 48 is preferably 90 L / h or less, more preferably 0 L / h. In addition, in a case where the supply of the particles is performed at the same time as the supply of the treatment water, it is preferable to reduce "the total flow rate of the treatment water and particles supplied from the semi-batch type biological treatment tank 80 or more". In addition, even if the operation of the first discharge water inflow pump 66 is stopped, the flow rate of the discharge water supplied to the continuous biological treatment device 48 from the discharge water inflow pipe 56a is reset to zero (even if the inflow of the discharge water from the discharge water inflow pipe 56a is stopped), Since the particles discharged from the semi-batch type biological treatment tank 80 also include treated water, and the treated water is supplied to the continuous biological treatment device 48 from the biological sludge supply pipe 64, it is possible to ensure that the water is discharged from the continuous biological device 48 Continuous supply.

Here, the particles formed in the semi-batch biological treatment tank 80 refer to sludge that is continuously self-granulated. For example, the average particle diameter of the sludge is 0.2 mm or more, or the sedimentation index SVI5 is 80 mL / g or less. Biological sludge. In this embodiment, whether or not particles have formed is determined by, for example, measuring SVI, which is an index of sedimentability of sludge. Specifically, the SVI value is periodically measured by the sedimentation test of the sludge in the semi-batch biological treatment tank 80, and the value of SVI5 calculated from the volume ratio after 5 minutes of sedimentation is below a predetermined value (for example, 80 mL / g or less) ) Stage, it can be judged that particles have formed. Alternatively, when the particle size distribution of the sludge in the semi-batch type biological treatment tank 80 is measured, and the average particle diameter becomes a predetermined value or more (for example, 0.2 mm or more), it can be determined that particles have formed (and the lower the SVI value, the average The larger the particle size, the better the granular sludge). Thereafter, the sludge supply pump 74 is operated, and the particles formed in the semi-batch type biological treatment tank 80 are supplied from the biological sludge supply pipe 64 to the continuous biological treatment device 48.

As described above, in the present embodiment, the increase in the flow load of the solid-liquid separation device 52 can be suppressed, and thus the biological sludge flowing out with the treated water discharged from the solid-liquid separation device 52 can be suppressed. Then, the treated water discharged from the solid-liquid separation device 52 is discharged out of the system through the treated water discharge pipe 58a. Further, the sludge return pump 76 is operated, and a part of the biological sludge separated by the solid-liquid separation device 52 is supplied to the continuous biological treatment device 48 through the sludge return pipe 60. Furthermore, by opening the solenoid valve 78, a part of the biological sludge discharged from the solid-liquid separation device 52 is discharged to the outside of the system through the sludge discharge pipe 62.

Hereinafter, modifications and the like regarding this embodiment will be described.

Although the semi-batch type biological treatment device 50 shown in FIG. 4 has been described as an example of a biological treatment in an aerobic condition, the biological treatment is only an anaerobic condition or only an anaerobic condition and only an aerobic condition. Conditions, anaerobic or anaerobic-aerobic conditions, etc. are not specifically limited. However, since the proliferation rate of biological sludge is increased by including aerobic conditions, it is preferable to include aerobic conditions from the viewpoint of particle formation speed. In addition, in the formation of particles, it is better to appropriately control the management of the sedimentation time and the discharge water inflow rate of each batch. The settling time for stopping the stirring (including stirring with aeration) to settle the sludge is calculated from the distance from the water surface to the sludge discharge section and the sludge settling speed. For example, it is preferably set to 4 minutes / m to 15 minutes / m, more preferably between 5 minutes / m and 10 minutes / m. The discharge water inflow rate (the ratio of the inflow water to the effective volume during the reaction) is preferably, for example, in a range of 20% to 120%, and more preferably in a range of 40% to 100%. It can be considered that the sludge is repeatedly subjected to a state in which "the concentration of the target substance, that is, the organic substance is very high" (immediately after the inflow step, and a state of satiety) and a state in which the "organic substance concentration is very low" (biological treatment At the end of the step, the state of starvation), and granulation of sludge, so from the viewpoint of forming particles, it is better to maximize the discharge water inflow rate, but on the other hand, the higher the discharge water inflow rate, the more it flows into the pump. The larger the capacity becomes, the more expensive it becomes. Therefore, from the viewpoints of particle formation and price reduction, the discharge water inflow rate is preferably in a range of 40% to 100%.

The semi-batch type biological treatment apparatus 50 is preferably operated in a range of, for example, a sludge concentration in the tank of 2000 to 20,000 mg / L. When the concentration of sludge increases beyond a predetermined concentration, it is better to extract the biological sludge from the tank. In addition, in order to maintain the integrity (sedimentation, activity, etc.) of the biological sludge, it is better to keep it at an appropriate sludge load, and it is better to extract the biological sludge from the tank to a level of 0.05 ~ 0.60 kg BOD / MLSS / day The range is better kept in the range of 0.1 ~ 0.5 kg BOD / MLSS / day.

The pH in the semi-batch biological treatment tank 80 is preferably adjusted to a range of 6 to 9 suitable for general biological treatment, and more preferably adjusted to a range of 6.5 to 7.5. When the pH value is out of the aforementioned range, it is preferable to perform pH adjustment using an acid and an alkali. When the pH is adjusted in the semi-batch biological treatment tank 80, from the viewpoint of proper pH measurement, it is better to perform the discharge water than the state of the discharged water in the unstirred semi-batch biological treatment tank 80. Adjust the pH while stirring. The dissolved oxygen amount (DO) in the semi-batch type biological treatment tank 80 is preferably 0.5 mg / L or more, and more preferably 1 mg / L or more suitable for general biological treatment.

The semi-batch type biological treatment apparatus 50 includes a device that performs simultaneous inflow of discharged water and discharge of treated water. That is, the three-step device that repeatedly performs (1) inflow of discharged water / discharge of treated water, (2) biological treatment of the treatment target substance, and (3) sedimentation of biological sludge is also a semi-batch of this embodiment.式 生物 处理 装置 50。 Biological treatment device 50. An example of a discharged water treatment device using a semi-batch type biological treatment device that repeatedly performs the three steps described above will be described later.

In the continuous biological treatment device 48 shown in FIG. 4, the type of biological treatment using a standard activated sludge method that uses organic matter as a treatment object is described as an example, but it is not limited to this case. For example, it may be used A2O (Anaerobic-Anoxic-Oxic Process) or AO (Anaerobic-Oxic Process) system (with anaerobic tank or anaerobic process) A system for biological treatment of systems such as a treatment tank system), an oxidation channel method (Oxidation Ditch), and a multi-stage activated sludge method. Moreover, it may be a device which performs biological treatment in the presence of a carrier such as polyurethane, plastic, and resin.

The continuous biological treatment device 48 is preferably operated, for example, in a sludge concentration range of 2000 to 20,000 mg / L in the tank. Moreover, in order to maintain the integrity (sedimentation, activity, etc.) of the biological sludge, the sludge load is preferably in the range of 0.05 to 0.6 kg BOD / MLSS / day, and more preferably in the range of 0.1 to 0.5 kg BOD / MLSS / day.

The pH value in the continuous biological treatment device 48 is preferably adjusted to a range of 6 to 9 suitable for general biological treatment, and more preferably adjusted to a range of 6.5 to 7.5. The amount of dissolved oxygen (DO) in the continuous biological treatment device 48 is preferably 0.5 mg / L or more, more preferably 1 mg / L or more, suitable for general biological treatment.

The discharged water treatment device 3 shown in FIG. 4 is described by taking a type including the solid-liquid separation device 52 as an example, but the solid-liquid separation device 52 is not necessarily required. However, from the viewpoint that the discharged water treatment device 3 circulates particles and improves the treatment efficiency of the discharged water, it is preferable to include a solid-liquid separation device 52 that separates biological sludge from the treated water discharged from the biological treatment device 48, and The biological sludge discharged from the solid-liquid separation device 52 is returned to the sludge return pipe 60 of the continuous biological treatment device 48.

FIG. 6 is a schematic diagram showing another example of the structure of the discharged water treatment device according to the embodiment. In the discharged water treatment device 4 of FIG. 6, the same configuration as that of the discharged water treatment device 3 shown in FIG. 4 is assigned the same reference numeral, and the description is omitted. In the drain water treatment device 4 shown in FIG. 6, a drain water inflow pump 68 and a first solenoid valve 82 are provided in the drain water inflow pipe 56a, and a second solenoid valve 84 is provided in the drain water inflow pipe 56b. One end of the drain water inflow pipe 56 b is connected to the drain water inflow pipe 56 a between the drain water inflow pump 68 and the first solenoid valve 82, and the other end is connected to the drain water inlet of the semi-batch type biological treatment device 50. The first solenoid valve 82 shown in FIG. 6 has a function of adjusting the flow rate of the discharged water supplied to the continuous biological treatment device 48 in accordance with the supply of the particles and the supply of the treated water. Specifically, the first solenoid valve 82 is electrically connected to the treated water discharge pump 72 and the sludge supply pump 74. When the treated water discharge pump 72 or the sludge supply pump 74 is operated, these pumps are operated. The output signal is sent to the first solenoid valve 82, and at the stage when the first solenoid valve 82 receives the output signal, the opening and closing degree of the first solenoid valve 82 is reduced to reduce the flow rate of the discharged water by a predetermined amount. Alternatively, at the stage when the first solenoid valve 82 receives the output signal, the first solenoid valve 82 is closed to zero the flow rate of the discharged water (that is, the supply of the discharged water from the discharged water inflow pipe 56a is stopped). Further, when the operation of the treated water discharge pump 72 or the sludge supply pump 74 is stopped and the transmission of the output signal is stopped, it is preferable to restore the opening and closing degree of the first solenoid valve 82 to the original state to restore the flow rate of the discharged water.

An example of the operation of the drain water treatment device 4 according to this embodiment will be described.

First, the discharged water inflow pump 68 is operated, and the first solenoid valve 82 is opened, and the discharged water from the processing target in the discharged water storage tank 54 is supplied to the continuous biological treatment device 48 through the discharged water inflow pipe 56a. As described above, the continuous biological treatment device 48 biologically treats the discharged water. The treated water is supplied to the solid-liquid separation device 52 through the drain water inflow pipe 56c.

Next, when the semi-batch type biological treatment device 50 is operated, the discharged water flows into the pump 68, the second solenoid valve 84 is opened in a state where the first solenoid valve 82 is opened, and the treatment in the discharged water storage tank 54 is performed. The target discharge water is supplied to the semi-batch type biological processing apparatus 50 from the discharge water inflow pipe 56b ((1) the flow of discharge water). The discharged water is introduced into the semi-batch biological treatment tank 80 until the predetermined amount is reached, and then the second solenoid valve 84 is closed.

Next, the air pump 88 is operated, air is introduced from the air diffusion device 90, and air is supplied into the semi-batch type biological treatment device 50, and the agitating device 86 is operated to agitate the half-batch type biological treatment device 50 The biological treatment of the discharged water ((2) biological treatment of the treatment target substance). Then, after a predetermined time has elapsed, the operation of the air pump 88 is stopped to stop the supply of air, and the stirring device 86 is stopped to end the biological treatment. After the biological treatment is completed, the biological sludge in the semi-batch type biological treatment device 50 is allowed to settle for a predetermined time, and the biological sludge and the treated water are separated in the half-batch type biological treatment device 50 ((3) sedimentation of the biological sludge). Then, the treatment water discharge pump 72 is operated, and the treatment water in the semi-batch type biological treatment device 50 is discharged through the treatment water discharge pipe 58b ((4) discharge of the treatment water), and the treatment water discharge pipe 58b is supplied to the continuous type. Biological treatment device 48. Next, the steps (1) to (4) are repeated. Further, by repeating the steps (1) to (4), particles are formed in the semi-batch type biological processing apparatus 50. However, for example, when the biological treatment is started (when the device is started) or when the particle concentration in the tank is significantly low, it is better to repeat the biological treatment step and the drainage water introduction sequentially. The process water discharge step replaces the steps (1) to (4) above to perform particle formation.

(4) In the step of discharging the treated water, at the stage where the first solenoid valve 82 receives the output signal during the operation of the treated water discharge pump 72, the opening and closing degree of the first solenoid valve 82 is reduced to reduce the supply to the continuous type. The inflow amount of the discharged water from the biological treatment device 48. Alternatively, the first solenoid valve 82 is closed, and the flow rate of the discharged water supplied to the continuous biological treatment device 48 is reset to zero (the supply of the discharged water from the discharged water inflow pipe 56a is stopped). After the predetermined time has elapsed, the operation of the treated water discharge pump 72 is stopped, and the process is shifted to (1) the inflow step of the discharged water again. At the time of the inflow of the discharged water, it is preferable to restore the opening and closing degree of the first solenoid valve 82 to the original state to restore the inflow of the discharged water to the continuous biological treatment device 48. In addition, in this embodiment, although the flow rate of the discharged water is reduced by the switch of the first solenoid valve 82, it is possible to reduce the output of the discharged water flowing into the pump 68 as in the discharged water treatment device 3 of FIG. 4. Reduce the flow of discharged water.

As described above, in the discharged water treatment device 4 of the present embodiment, the supply of the treated water from the continuous biological treatment device 48 by the semi-batch biological treatment device 50 accompanies the discharge to the continuous biological treatment device 48. Since the inflow of water is reduced or returned to zero, an increase in the amount of water flowing into the continuous biological treatment device 48 can be suppressed. As a result, it is possible to suppress an increase in the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48, and further suppress an instantaneous increase in the flow load on the solid-liquid separation device 52. Therefore, it is possible to suppress the discharge together with the treated water. Of biological sludge.

In addition, by operating the sludge supply pump 74, the particles formed in the semi-batch type biological treatment apparatus 50 are supplied to the continuous biological treatment apparatus 48 from the biological sludge supply pipe 64. At the stage where the first solenoid valve 82 receives the output signal of the sludge supply pump 74, the degree of opening and closing of the first solenoid valve 82 is reduced to reduce the flow rate of the discharged water supplied to the continuous biological treatment device 48. Alternatively, the first solenoid valve 82 is closed, and the flow rate of the discharged water supplied to the continuous biological treatment device 48 is reset to zero. This makes it possible to suppress an increase in the amount of water flowing into the continuous biological treatment device 48. As a result, it is possible to suppress an increase in the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48, and further suppress an instantaneous increase in the flow load to the solid-liquid separation device 52. Therefore, it is possible to suppress the discharge together with the treated water. Of biological sludge.

In addition, like the drain water treatment device 4 of the present embodiment, the type of the device that supplies the drain water to the continuous biological treatment device 48 and the semi-batch biological treatment device 50 with the same pump is different from the device type The type of the apparatus that supplies the discharged water to the continuous biological treatment apparatus 48 and the semi-batch biological treatment apparatus 50 in other pumps can reduce the purchase cost and operating cost of the apparatus.

Next, an example of the operation of the discharged water treatment device 4 using the semi-batch type biological treatment device 50 in which the discharged water is introduced and the treated water is discharged will be described. That is, the three steps of (1) inflow of discharged water / discharge of treated water, (2) biological treatment of a treatment target substance, and (3) sedimentation of biological sludge are repeated in the semi-batch type biological treatment apparatus 50. Furthermore, by repeating the steps (1) to (3), particles are formed in the semi-batch type biological processing apparatus 50. However, for example, when the biological treatment is started (when the device is started) or when the particle concentration in the tank is significantly decreased, it is preferable to repeat the aforementioned biological treatment step and the introduction of drain water in order. The process water discharge step replaces the steps (1) to (3) above to perform particle formation.

First, the discharged water inflow pump 68 is operated, the first solenoid valve 82 is opened, and the discharged water from the processing target in the discharged water storage tank 54 is supplied to the continuous biological treatment device 48 from the discharged water inflow pipe 56a. After the continuous biological treatment device 48 performs biological treatment of the discharged water, the treated water is supplied from the discharged water inflow pipe 56 c to the solid-liquid separation device 52. Next, when the semi-batch type biological treatment device 50 is operated, the second solenoid valve 84 is opened, the treated water discharge pump 72 is operated, and the discharged water is supplied to the semi-batch type biological treatment device 50 from the discharged water inflow pipe 56a. The biologically treated water in the semi-batch type biological treatment device 50 is supplied to the continuous biological treatment device 48 through the treatment water discharge pipe 58b ((1) inflow of discharged water / discharge of treated water). At this time, in the present embodiment, at the stage where the first solenoid valve 82 has received the output signal during the operation of the treated water discharge pump 72, the degree of opening and closing of the first solenoid valve 82 is reduced, and the supply to the continuous biological treatment device is reduced. 48 inflows of discharged water. Alternatively, the first solenoid valve 82 is closed, and the inflow amount of the discharged water supplied to the continuous biological treatment device 48 is reset to zero (the supply of the discharged water is stopped).

After a predetermined time has elapsed, the operation of the treated water discharge pump 72 is stopped, and the second solenoid valve 84 is closed. At this time, it is preferable to return the opening and closing degree of the first solenoid valve 82 to the original state to restore the inflow of the discharged water to the continuous biological treatment device 48. Next, the air pump 88 is operated, air is introduced from the air diffusion device 90, and air is supplied to the semi-batch type biological treatment device 50, and the stirring device 86 is operated, and the semi-batch type biological treatment device 50 is stirred Biological treatment of the discharged water ((2) biological treatment of the treatment target substance). Then, after a predetermined time elapses, the operation of the air pump 88 is stopped to stop the supply of air, and the stirring device 86 is stopped to end the biological treatment. After the biological treatment is completed, the biological sludge in the semi-batch type biological treatment device 50 is allowed to settle for a predetermined time, and the biological sludge and the treated water are separated in the half-batch type biological treatment device 50 ((3) sedimentation of the biological sludge). After that, the process is shifted to (1) the inflow of the discharged water again. Also, the case where the particles formed in the semi-batch type biological treatment device 50 are supplied to the continuous type biological treatment device 48 is the same as described above, and it is at a stage where the output signal of the sludge supply pump 74 is received, and the first electromagnetic field is reduced. The opening / closing degree of the valve 82 reduces or resets the inflow amount of the discharged water supplied to the continuous biological treatment device 48.

As described above, in the discharged water treatment device 4 according to this embodiment, the supply of the treated water and particles from the continuous biological treatment device 48 by the semi-batch biological treatment device 50 reduces the supply to the continuous biological treatment device 48. The inflow of the discharged water can suppress an increase in the amount of water flowing into the continuous biological treatment device 48. As a result, an increase in the amount of biological sludge contained in the treated water discharged from the continuous biological treatment device 48 is suppressed, and further, an instantaneous increase in the flow load on the solid-liquid separation device 52 is suppressed, so that the discharge with the treated water can be suppressed. The amount of biological sludge.

FIG. 7 is a schematic diagram showing another example of the structure of the discharged water treatment device according to the embodiment. In the discharged water treatment device 5 shown in FIG. 7, the same reference numerals are assigned to the same configuration as the discharged water treatment device 4 shown in FIG. 6, and descriptions thereof are omitted. In the discharged water treatment device 5 shown in FIG. 7, a third solenoid valve 92 is provided in the treated water discharge pipe 58 b (the treated water discharge pump 72 is not provided). In the discharged water treatment device 5 of FIG. 7, the switch of the third solenoid valve 92 is used to supply the treated water. Stop, instead of the operation of the treated water discharge pump 72 shown in Figure 6. Except for stopping, the same operation as that of the discharged water treatment device 4 shown in FIG. 6 is performed. Compared with the discharged water treatment device 4 shown in FIG. 6, the discharged water treatment device 5 shown in FIG. 7 has a structure that reduces the number of pumps, resulting in a lower purchase cost and operating cost of the device.

FIG. 8 is a schematic diagram showing another example of the structure of the discharged water treatment device according to the embodiment. The drain water treatment device 6 shown in FIG. 8 has the same configuration as the drain water treatment device 4 shown in FIG. 6, and the same reference numerals are assigned, and descriptions thereof are omitted. The discharged water treatment device 6 shown in FIG. 8 includes a sludge treatment water supply pipe 94 that supplies the treatment water and particles discharged from the semi-batch biological treatment device 50 to the continuous biological treatment device 48. A third solenoid valve 96 is provided in the sludge treatment water supply pipe 94. The sludge treatment water supply pipe 94 has a function as a treatment water supply device for supplying the treatment water discharged from the semi-batch type biological treatment device 50 to the continuous biological treatment device 48, and a function for supplying particles to the continuous biological treatment device 48. Function of biological sludge supply device. The third solenoid valve 96 is electrically connected to the first solenoid valve 82. When the third solenoid valve 96 is opened, the third solenoid valve 96 sends the output signal to the first solenoid valve 82. At the stage when the first solenoid valve 82 receives the output signal, the opening degree of the first solenoid valve 82 is reduced, and The amount of discharged water is reduced by a certain amount. Alternatively, at the stage when the first solenoid valve 82 receives the output signal, the first solenoid valve 82 is closed to zero the flow rate of the discharged water (that is, the supply of the discharged water from the discharged water inflow pipe 56a is stopped). In addition, it is preferable to adopt the following structure: once the third solenoid valve 96 is closed, the transmission of the output signal is stopped; when the transmission of the output signal is stopped, the opening and closing degree of the first solenoid valve 82 is restored to the original state, and the flow rate of the discharged water is restored .

In the discharged water treatment device 6 shown in FIG. 8, the following semi-batch type biological treatment device 50 is used: in a state where the liquid (processed water and particles) in the semi-batch type biological treatment device 50 is stirred, The batch type biological treatment device 50 introduces the discharged water, and discharges the processed water and particles from the semi-batch type biological treatment device 50. Hereinafter, the operation of the discharged water treatment device 6 shown in FIG. 8 will be described as an example.

First, the discharged water inflow pump 68 is operated, and the first solenoid valve 82 is opened to continuously supply the discharged water to be treated in the discharged water storage tank 54 from the discharged water inflow pipe 56 a to the continuous biological treatment device 48. After the continuous biological treatment device 48 performs biological treatment of the discharged water, the treated water is supplied from the discharged water inflow pipe 56 c to the solid-liquid separation device 52. Next, when the semi-batch type biological treatment device 50 is operated, the second solenoid valve 84 and the third solenoid valve 96 are opened, and the discharged water is supplied to the semi-batch type biological treatment device 50 from the discharged water inflow pipe 56b, and The treated water in the batch biological treatment device 50 is supplied to the continuous biological treatment device 48 from the sludge treatment water supply pipe 94 ((1) inflow of discharged water / discharge of treated water). At this time, in the present embodiment, at the stage when the first solenoid valve 82 receives the output signal when the third solenoid valve 96 is opened, the degree of opening and closing of the first solenoid valve 82 is reduced, and the supply to the continuous biological processing device 48 is reduced. Inflow of discharged water. Alternatively, the first solenoid valve 82 is closed, and the inflow amount of the discharged water supplied to the continuous biological treatment device 48 is reset to zero (the supply of the discharged water is stopped). Next, while maintaining the open and closed states of the valves, the agitating device 86 is operated, and the treated water and particles agitated by the agitating device in the semi-batch type biological treatment device 50 are supplied from the sludge treatment water supply pipe 94 to Continuous biological treatment device 48 ((1.5) supply of granular sludge).

After a predetermined time has elapsed, the second solenoid valve 84 and the third solenoid valve 96 are closed. At this time, it is preferable to restore the opening / closing degree of the first solenoid valve 82 to the original state and restore the inflow amount of the discharged water to the continuous biological treatment device 48. Next, the air pump 88 is operated without stopping the operation of the stirring device 86. The air is introduced from the air diffusion device 90, and the biological treatment of the discharged water is started by supplying air to the semi-batch type biological treatment device 50 ((2) Biological treatment step). Then, after a predetermined time elapses, the operation of the stirring device 86 is stopped, the operation of the air pump 88 is stopped, and the biological treatment is terminated by stopping the supply of air. After the biological treatment is completed, the biological sludge in the semi-batch type biological treatment device 50 is allowed to settle for a predetermined time, and the biological sludge and the treated water are separated in the half-batch type biological treatment device 50 ((3) sedimentation of the biological sludge). Then, it shifts again to (1) the inflow of the discharged water / the discharged | emitted process water. (1.5) The step of supplying granular sludge does not need to be performed every cycle, and may be performed at a rate of once in several cycles.

Next, another example of the operation of the discharged water treatment device 6 shown in FIG. 8 will be described below.

First, the discharged water inflow pump 68 is operated, and the first solenoid valve 82 is opened, and the discharged water from the processing target in the discharged water storage tank 54 is continuously supplied to the continuous biological treatment device 48 from the discharged water inflow pipe 56a. After the biological treatment of the discharged water is performed in the continuous biological treatment device 48, the treated water is supplied from the discharged water inflow pipe 56c to the solid-liquid separation device 52. Next, when the semi-batch type biological treatment device 50 is operated, the second electromagnetic valve 84 and the third solenoid valve 96 are opened, and the stirring device 86 is operated, and the discharged water is supplied to the semi-batch biological treatment from the discharged water inflow pipe 56b. Device 50, and supplies the treated water and particles agitated by the stirring device in the semi-batch type biological treatment device 50 to the continuous biological treatment device 48 from the sludge treatment water supply pipe 94 ((1) inflow / treatment water of discharged water 'S discharge). At this time, in the present embodiment, at the stage when the first solenoid valve 82 receives the output signal when the third solenoid valve 96 is opened, the degree of opening and closing of the first solenoid valve 82 is reduced, and the supply to the continuous biological processing device 48 is reduced. Inflow of discharged water. Alternatively, the first solenoid valve 82 is closed, and the inflow amount of the discharged water supplied to the continuous biological treatment device 48 is reset to zero (the supply of the discharged water is stopped).

After a predetermined time has elapsed, the second solenoid valve 84 and the third solenoid valve 96 are closed. At this time, it is preferable to restore the opening and closing degree of the first solenoid valve 82 to the original state so as to restore the inflow amount of the discharged water to the continuous biological treatment device 48. Next, the air pump 88 is operated without stopping the operation of the stirring device 86. The air is introduced from the air diffusion device 90, and the biological treatment of the discharged water is started by supplying air to the semi-batch type biological treatment device ((2) biological Processing steps). Then, after a predetermined time elapses, the supply of air is stopped by stopping the operation of the air pump 88 to end the biological treatment. After that, in a state in which the stirring device 86 is operated, that is, in a state in which the liquid in the semi-batch type biological treatment device 50 is stirred, the drain water is again flowed into the semi-batch type biological treatment device 50, and the semi-batch type biological treatment is performed. The device 50 discharges treated water and particles ((1) inflow of discharged water / discharge of treated water).

It has a function as a treatment water supply device that supplies the treated water discharged from the semi-batch type biological treatment device 50 to the continuous biological treatment device 48, and a function as a biological sludge supply device that supplies particles to the continuous biological treatment device 48. The sludge treatment water supply pipe 94 is not limited to be applied to the discharged water treatment device shown in FIG. 8, and is also applicable to all the embodiments described above.

9 (A) and 9 (B) are schematic diagrams showing another example of the configuration of the semi-batch type biological treatment apparatus used in the embodiment. The half-batch type biological treatment device 98 shown in FIG. 9 has the same configuration as the half-batch type biological treatment device 50 shown in FIG. 5, and the same reference numerals are assigned, and descriptions thereof are omitted. In the semi-batch type biological treatment apparatus 98 shown in FIG. 9 (A), the treated water outlet 50b that discharges treated water is provided at a position higher than the discharged water inlet 50a that flows into the discharged water. Also, the half-batch type biological treatment device 98 shown in FIG. 9 (B) is a half-batch type biological treatment device 50 used for the drain water treatment device of FIG. 8, and a sludge treatment water outlet 50d that discharges treatment water and particles is provided. At a position higher than the discharge water inlet 50a into which the discharge water flows. Thereby, since the shortcut for allowing the discharged discharged water to be discharged from the semi-batch type biological treatment device 98 without biological treatment is suppressed, particles can be efficiently formed in the semi-batch type biological treatment device 98. In addition, since the treated water in the semi-batch type biological treatment device 98 is discharged in the form of being pushed upward by the inflowing discharged water, biological sludge with low sedimentation property can be actively discharged out of the system. As a result, since the highly sludge-containing biological sludge is left in the semi-batch type biological processing apparatus 50, particles can be formed more efficiently. In addition, although the treated water flowing out of the semi-batch type biological treatment device 98 may be mixed with the discharged water before treatment, the quality of the treated water may be deteriorated. However, the treated water discharged from the half-batch type biological treatment device 98 is supplied to The continuous biological treatment device 48 performs biological treatment here, so that deterioration of the quality of the finally obtained treated water can be suppressed. [Example]

Hereinafter, the present invention will be described in more detail with examples, but the present invention is not limited to the following examples.

In the embodiment, the semi-batch type biological treatment apparatus shown in FIG. 2 was used, and the treatment of the simulated discharged water was performed under the following conditions. In the embodiment, the discharge water flow inlet is set at a position of 1/4 of the water surface height of the semi-batch type biological treatment tank (height 0.05m from the bottom of the tank), and the treated water flow outlet is set at the water surface to be located The semi-batch biological treatment tank (the size of the semi-batch biological treatment tank: W0.15m × L0.2m × H0.4m) at a position higher than the discharge water outlet (height 0.2m from the bottom of the tank). The drainage system for simulation uses fish extract and peptone as the main body.

The simulated discharge water introduced into the semi-batch biological treatment tank is supplied with air for a predetermined time (150 minutes) by an aeration device installed at the bottom of the semi-batch biological treatment tank, and the biological treatment of the simulated discharge water is performed. (Biological treatment step). After 30 seconds from stopping the aeration device (area settling time obtained in advance from the graduated cylinder), the introduction of the discharged water from the discharge water inlet and the discharge of the treated water from the treatment water outlet (the discharge water introduction. The treatment water discharge step) ). The inflow linear velocity of the discharged water is 1 m / h relative to the water area of the semi-batch biological treatment tank. In addition, the inflow of the discharged water was 75% of the actual volume of the semi-batch biological treatment tank in 18 minutes. Repeated implementation of such biological treatment and drainage water introduction. Process water discharge step.

(Comparative example) The above-mentioned simulated discharge water treatment was performed under the following conditions. In the comparative example, the discharge water flow inlet was set at a position of 1/4 of the water surface height of the semi-batch type biological treatment tank (the height of 0.1 m from the bottom of the tank), and the treatment water flow outlet was set at the water level of the half-batch biological treatment tank. A half-batch biological treatment tank (half-batch biological treatment tank size: W0.15m × L0.2m × H0.4m) at a position of 1/2 (height 0.2m from the bottom of the tank).

In the comparative example, a conventional semi-batch process was performed. First, (1) the inflow of the discharged water, the raw water is introduced into the semi-batch type biological treatment tank from the discharged water inlet in 10 minutes. (2) The biological treatment of the treatment target substance is a biological treatment in which simulated air is discharged by supplying air for 95 minutes using an aeration device provided at the bottom of the semi-batch type biological treatment tank. (3) The sedimentation of biological sludge is the sedimentation of biological sludge for 15 minutes after the aeration device is stopped. (4) The treated water is discharged from the treated water outlet for 10 minutes. The above steps (1) to (4) are repeated.

The examples were performed together with the comparative examples, and the SVI5 of the biological sludge in the semi-batch biological treatment tank was measured in chronological order. In addition, "SVI5" is a settling index of biological sludge, and it was calculated | required by the following method. First, 1 L of sludge was put into a 1 L graduated cylinder, and after stirring, the interface of the sludge when standing for 5 minutes was measured. Next, the occupied volume ratio (%) of the sludge in the graduated cylinder was calculated. Then, the MLSS (mg / L) of the sludge was measured. These data are substituted into the following formula to calculate SVI5. The smaller the value of SVI5 is the sludge with higher sedimentability. SVI5 (mL / g) = Volume ratio occupied by sludge × 10,000 / MLSS

Table 1 is a representative example of treated water quality on the 26th day from the start of water delivery in the examples and comparative examples. FIG. 10 is a diagram showing daily changes of SV15 of Examples and Comparative Examples. It can be obtained that the dissolved BOD can be suppressed to 10 mg / L or less, and the SS (suspended solid) is also very good in treating water quality. At the start of the test, the SVI5 values of Example 1 and Comparative Example were both about 50 mL / g. However, in the examples, the value of SVI5 decreased with the passage of days, and reached a very low value of 26 mL / g on the 26th day after the start of the test. On the other hand, in the comparative example, even if the number of days passed, the value of SVI5 did not change much, and it was 47 mL / g on the 26th day from the start of the test. Therefore, as in Example 1, by repeatedly carrying out: "The biological treatment step, in a state where the inflow of the discharged water and the discharge of the treated water are stopped, while the discharged water is stirred, the discharged water is biologically treated with biological sludge; and Drainage water is introduced. The treatment water discharge step starts from stopping the agitation of the discharge water to the sludge interface forming the biological sludge. The discharge water is introduced from the discharge water inlet installed at a position lower than the treatment water outlet, and is discharged from the treatment water outlet. Treating water "; Compared with the conventional semi-batch treatment as in Comparative Example 1, biological sludge with high sedimentation can be formed, and biological sludge with high sedimentation can be formed in a short time.

[Table 1] Treatment water quality on day 26

1, 2, 50, 98‧‧‧ Half-batch biological treatment device

3 ~ 6‧‧‧ discharge water treatment device

10‧‧‧Semi-batch biological treatment tank

12‧‧‧ drainage water introduction device

14‧‧‧Distributor

16‧‧‧ treatment water discharge device

20‧‧‧Control device

22‧‧‧ Drain water inlet

24‧‧‧ treatment water outlet

26‧‧‧ Drain water introduction pipe

28‧‧‧ Drain water pump

30‧‧‧Discharge water side solenoid valve

32‧‧‧ treatment water discharge pipe

34‧‧‧Solenoid valve on the water side

36, 86‧‧‧ mixing device

38‧‧‧aeration device

40‧‧‧Motor

42‧‧‧ stirring blade

44‧‧‧Air diffusion pump

46‧‧‧Air diffuser

48‧‧‧Continuous biological treatment device

50a‧‧‧Discharge water inlet

50b‧‧‧ treated water outlet

50c‧‧‧Sludge export

50d‧‧‧Sludge treatment water outlet

52‧‧‧Solid-liquid separation device

54‧‧‧ Drain water storage tank

56a, 56b, 56c ‧‧‧ discharge water inflow pipe

58a, 58b ‧‧‧ treatment water discharge pipe

60‧‧‧Sludge return pipe

62‧‧‧Sludge discharge pipe

64‧‧‧ biological sludge supply pipe

66‧‧‧The first discharge water flows into the pump

68‧‧‧ Drained water flows into pumps

70‧‧‧Second discharge water flows into pump

72‧‧‧ treatment water discharge pump

74‧‧‧Sludge supply pump

76‧‧‧Sludge returned to Pupu

78‧‧‧ Solenoid Valve

80‧‧‧Semi-batch biological treatment tank

82‧‧‧The first solenoid valve

84‧‧‧The second solenoid valve

88‧‧‧air pump

90‧‧‧air diffusion device

92, 96‧‧‧ 3rd solenoid valve

94‧‧‧Sludge treatment water supply pipe

[FIG. 1] A schematic diagram showing an example of the configuration of a semi-batch type biological treatment apparatus related to the embodiment. FIG. 2 is a schematic diagram showing another example of the configuration of the semi-batch type biological treatment apparatus according to the embodiment. Fig. 3 is a diagram showing an example of a settlement curve. [Fig. 4] Fig. 4 is a schematic diagram showing an example of a configuration of a drain water treatment device according to the embodiment. FIG. 5 is a schematic diagram showing an example of a configuration of a semi-batch type biological treatment apparatus used in this embodiment. FIG. 6 is a schematic diagram showing another example of the configuration of the drain water treatment device according to the embodiment. [FIG. 7] A schematic diagram showing another example of the configuration of the discharged water treatment device according to the embodiment. [Fig. 8] Fig. 8 is a schematic diagram showing another example of the configuration of the drain water treatment device according to the embodiment. [Fig. 9] (A) and (B) are schematic diagrams showing another example of the configuration of the semi-batch type biological treatment apparatus used in the embodiment. FIG. 10 is a diagram showing daily changes of SV15 in Examples and Comparative Examples.

Claims (13)

A method for treating discharged water, comprising a semi-batch biological treatment step for biologically treating the discharged water using a semi-batch biological treatment tank containing biological sludge, which is characterized in that the semi-batch biological treatment step includes a biological treatment step, When the introduction of the discharged water to the semi-batch biological treatment tank and the discharge of the treated water from the semi-batch biological treatment tank are stopped, the discharged water in the semi-batch biological treatment tank is stirred, and the Biological sludge biologically treats the discharged water; and introduces the discharged water. The treatment water discharge step starts from stopping the stirring of the discharged water in the semi-batch type biological treatment tank, and until the sludge layer of the biological sludge is formed in the semi-batch type biological treatment tank, the half-batch is started. The biological water treatment tank introduces the discharged water, and starts to discharge the treated water from the semi-batch biological treatment tank; and the discharged water treatment method repeats the biological treatment step and the drainage water introduction sequentially. Process water discharge step. For example, the drainage water treatment method in the scope of patent application item 1, wherein the drainage water is introduced. The treatment water discharge step is at the same time as or immediately after the discharge water stirring in the semi-batch biological treatment tank is stopped, the introduction of the discharge water into the semi-batch biological treatment tank, and the semi-batch biological treatment tank The treatment tank discharges the treated water. For example, the method for treating discharged water in item 1 or 2 of the patent application scope further includes: a continuous biological treatment step for biologically treating the discharged water continuously flowing into the continuous biological treatment tank containing the biological sludge; biological sludge supply In step, the particles formed in the semi-batch biological treatment step are supplied to the continuous biological treatment tank; in the treatment water supply step, the treated water discharged from the half-batch biological treatment step is supplied to the continuous biological treatment tank ; And a discharge water flow adjustment step, accompanied by the supply of the particles through the biological sludge supply step, and the supply of the treated water through the treated water supply step, and reducing the flow into the continuous biological treatment tank The flow of the discharged water. The method for treating discharged water according to item 3 of the patent application scope, wherein in the step of adjusting the discharged water flow rate, the supply of the particles through the biological sludge supply step and the treatment through the treated water supply process Water supply, and the flow rate of the discharged water flowing into the continuous biological treatment tank is reset to zero. The method for treating discharged water according to item 1 or 2 of the patent application scope, wherein the semi-batch biological treatment tank is provided with: a discharge water inlet for allowing the discharged water to flow into the semi-batch biological treatment tank; and The treatment water outlet outside the treatment water discharge tank, or the sludge treatment water outlet for discharging the treatment water and the particles out of the tank is disposed at a position higher than the discharge water inlet. A drainage water treatment device, comprising: a semi-batch biological treatment tank containing biological sludge in the tank; introduction means for introducing the discharged water into the semi-batch biological treatment tank; and drainage means for the semi-batch biological treatment tank The treated water in the treatment tank is discharged to the outside of the tank; the stirring means stirs the discharged water in the semi-batch biological treatment tank; the first control means controls the operation of the stirring means; and the second control means controls the introduction means and The operation of the discharge means; wherein, when the first control means uses the biological sludge to biologically treat the discharged water, the discharged water is introduced into the semi-batch biological treatment tank, and the semi-batch type When the discharge of the treated water in the biological treatment tank is in a stopped state, the stirring means is operated to stir the discharged water in the biological treatment tank; and the second control means stops the discharged water by the stirring means from stopping. After the stirring, until the sludge layer of the biological sludge is formed in the biological treatment tank, the introduction means is operated, the drainage water is introduced into the semi-batch biological treatment tank, and The discharge means is operated, and the treatment water is started to be discharged from the semi-batch type biological treatment tank. For example, in the discharged water treatment device of the scope of application for patent No. 6, wherein the second control means stops the stirring of the discharged water by the stirring means or immediately after the stopping, the introduction means is operated to start the half-batch The biological water treatment tank introduces the discharged water, operates the drainage means, and starts to discharge the treated water from the semi-batch biological treatment tank. For example, the discharged water treatment device in the scope of patent application No. 6 or 7, wherein the second control means makes the introduction means and the discharge means operate so that the amount of the discharged water introduced into the semi-batch type biological treatment tank and The amount of treated water discharged from the semi-batch type biological treatment tank becomes equal. For example, the waste water treatment device of the scope of application for patent No. 6 or 7, wherein the semi-batch type biological treatment tank is provided with a discharge water inlet for allowing the discharged water to flow into the tank, and for discharging the treated water to the tank An external treatment water flow outlet; the discharge water flow inlet is arranged at a position lower than the treatment water flow outlet. For example, the discharged water treatment device according to item 9 of the patent application scope, wherein the treated water outflow port is provided at a water surface height of the discharged water in the semi-batch type biological treatment tank when the discharge of the treated water is stopped. For example, the discharge water treatment device in the scope of application for the patent No. 6 or 7, further includes: a continuous biological treatment device, which biologically treats the continuous inflow of discharged water; biological sludge supply means will be in the semi-batch biological treatment device The formed particles are supplied to the continuous biological treatment device; a treatment water supply means for supplying the treated water discharged from the semi-batch biological treatment device to the continuous biological treatment device; and a discharge water flow adjustment means for adjusting the inflow to the continuous biological treatment device Flow rate of the discharged water of the biological treatment device; wherein the adjustment means of the discharged water flow rate is accompanied by the supply of the particles by the biological sludge supply means and the supply of the treated water by the treated water supply means, and The flow rate of the discharged water flowing into the continuous biological treatment device is reduced. For example, the discharged water treatment device according to item 11 of the patent application scope, wherein the discharged water flow adjustment means is accompanied by the supply of the particles by the biological sludge supply means and the supply of the treated water by the treated water supply means , The flow rate of the discharged water flowing into the continuous biological treatment device is reset to zero. For example, the discharged water treatment device in the scope of patent application No. 6 or 7, wherein the semi-batch type biological treatment device is provided with: a discharge water inlet for allowing the discharged water to flow into the tank; and for discharging the treated water out of the tank The treated water outlet, or the sludge treated water outlet for discharging the treated water and the particles out of the tank, is disposed at a position higher than the discharged water inlet.