JP2011240342A - Wastewater treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wastewater treatment apparatus using a compact filtration device which can efficiently purify raw water even containing a large amount of contaminants and having a high SS concentration, and can minimize clogging of a screen and a filter medium.SOLUTION: This wastewater treatment includes: a biofilm reactor 30 for the biological treatment of the raw water; and a post-filteration device 40 for the filtration treatment of the biologically treated water derived from the biofilm reactor 30. The biofilm reactor 30 is a fluidized-bed biofilm reactor including: carrier support plates 31 provided in an upper part and a lower part in a sealed container, respectively; a biological carrier 32 filled between the carrier support plates 31 and having a specific density within 0.95-1.05; and a raw water inlet and a treated water outlet provided above the upper carrier support plate 31 and under the lower carrier support plate 31, respectively; and an air diffusion means 33 for stirring the biological carrier 32 by the diffused air.

Description

  The present invention relates to a wastewater treatment apparatus using a filtration apparatus, and more particularly to a wastewater treatment apparatus using a filtration apparatus that contains a large amount of impurities and is suitable for purification of raw water having a high SS concentration.

  In a filtration apparatus that treats raw water with a high concentration of SS and containing a large amount of foreign substances, a screen is provided on the upper part of the filter medium so that the filter medium is not blocked, and the raw water is swirled to trap the foreign substances. (For example, refer to Patent Document 1).

  In addition, there is also a filtration device that is provided with a diffuser means and a backwash water introduction part to purify the raw water, while being able to perform washing regeneration processing of the clogged filter medium (see, for example, Patent Document 2).

JP-A-4-225804 JP 2005-144230 A

  However, in the above-described filtering device of Patent Document 1, the screen is clogged with the continuation of the filtering process, and thus the screen has to be frequently washed. Further, in the filtering device of Patent Document 2, since there is no screen or scraper, when processing raw water having a high SS concentration, the filter medium must be frequently washed and regenerated so that the filter medium is not clogged. It was.

  Accordingly, the present invention provides a compact filtration device that can efficiently filter even raw water with a high content of impurities and high SS concentration, and that prevents clogging of screens and filter media as much as possible. It aims at providing the waste water treatment equipment using an apparatus.

  In order to achieve the above object, the wastewater treatment apparatus of the present invention performs a biofilm reactor for biological treatment by bringing raw water into contact with an aerobic microorganism carrier, and a filtration treatment of biologically treated water derived from the biofilm reactor. In the wastewater treatment apparatus including a post-filtration device, the biofilm reactor has a carrier support plate provided above and below the inside of the sealed container, and a specific gravity filled between both carrier support plates of 0.95 to 0.95. A biological carrier in the range of 1.05; a raw water inflow portion and a treated water outlet portion provided above the upper carrier support plate and below the lower carrier support plate; A post-filter device comprising: a filter medium support plate provided in a lower part of a sealed filtration container; and a filter medium filled in an upper part of the filter medium support plate. A screw ribbon type stirrer for stirring the filter medium provided in the central part of the filtration container, a biological treatment water inflow part provided above the filling part of the filter medium, and a backwash provided below the filtration container The screw ribbon stirrer includes a rotary shaft having an air passage therein, and projects from the peripheral wall of the rotary shaft in a radial direction to support the screw ribbon and the rotary shaft. A plurality of screw support members having air passages communicating with the air passages, a plurality of air diffuser holes provided in the screw support members, and air diffused air supplied from the air passages of the rotary shaft A diffused air supply means for diffusing from the diffuser holes through an air passage of a member, and the raw water is pumped by a raw water pump and is supplied to the biofilm reactor and the post-filter device. It is characterized by being sequentially supplied to.

  In addition, the biofilm reactor includes a pre-filtration device that performs a raw water filtration process in front of the biofilm reactor, and the pre-filtration device includes a screen provided above the inside of a sealed filtration container, and the filtration A filter medium support plate provided below the inside of the container, a filter medium filled between the filter medium support plate and the screen, a scraper for scraping off foreign matter trapped on the screen, and scraped by the scraper. A screen debris discharge unit for discharging foreign matters to the outside of the filtration container, a raw water inflow unit provided above the screen, a filtrate discharge unit provided below the filter medium support plate, and a lower part of the filtration container The raw water is pumped by a raw water pump and passes through the biofilm reactor from the prefiltration device and the postfiltration device. It is characterized by being sequentially supplied to.

  In the wastewater treatment apparatus of the present invention, since the fluidized bed biofilm reactor and the post-filtration device are formed in a sealed container, the raw water can be sequentially supplied to the biofilm reactor and the post-filtration device by the raw water pump, and the water head is secured. Since it is not necessary, the height of the biofilm reactor and the post-filtration device can be kept low, and a compact and highly efficient wastewater treatment device can be obtained. Furthermore, since the prefiltration apparatus formed with the airtight container is disposed in the front stage of the fluidized bed biofilm reactor, the raw water containing a large amount of impurities can be efficiently treated.

It is a systematic diagram which shows one example of the waste water treatment apparatus of this invention. It is a longitudinal cross-sectional view which shows one example of a prefiltration apparatus. It is a longitudinal cross-sectional view which shows one example of a biofilm reactor. It is a longitudinal cross-sectional view which shows one example of a back filtration apparatus. It is a longitudinal cross-sectional view which shows the other example of a back filtration apparatus. It is a cross-sectional top view which shows an example of the filtration apparatus which uses a cylindrical filtration container. It is a cross-sectional top view which shows an example of the filtration apparatus which uses a rectangular tube-shaped filtration container. It is explanatory drawing which shows the example which installed the several filtration apparatus in the filtration pond.

  1 is a system diagram showing an embodiment of the wastewater treatment apparatus of the present invention, FIG. 2 is a longitudinal sectional view showing an embodiment of a prefiltration apparatus, and FIG. 3 is a longitudinal sectional view showing an embodiment of a biofilm reactor. FIG. 4 is a longitudinal sectional view showing an example of a post-filtration device.

  First, as shown in FIG. 1, the wastewater treatment apparatus 1 shown in this embodiment includes a water intake unit 10, a pre-filtration device 20, a biofilm reactor 30, a post-filtration device 40, a chlorine mixing tank 50, A water supply device 60 is provided in order, and further, a raw water pump 71 for sequentially feeding raw water to the pre-filtration device 20, the biofilm reactor 30, the post-filtration device 40, and the chlorine mixing tank 50, and the water supply device 60 from the chlorine mixing tank 50. A water feed pump 72 for feeding filtrate water to the back, a backwash pump 73 for feeding backwash water to the pre-filter device 20 and the post-filter device 40, and an air wash for the pre-filter device 20 and the post-filter device 40 And an air blower 75 for sending air to the biofilm reactor 30.

  As shown in FIG. 2, the prefiltration device 20 is provided with a sealed container 20a, a hopper-like screen 21 which is provided above the inside of the sealed container 20a and gradually becomes concave toward the center, and the sealed container 20a. A filter medium support plate 22 provided below the inside and having a water flow structure, a raw water inflow portion 20b provided above the screen 21, a filtrate water outlet 20c provided below the filter medium support plate 22, A filter medium 23 filled between the filter medium support plate 22 and the screen 21 is provided.

  In addition, a scraper 24 that scrapes and collects impurities trapped on the screen 21 is rotatably provided on the upper surface of the screen 21, and the scraper 24 scrapes the central portion of the screen 21 with the scraper 24. A screen debris discharge part 25 for discharging the collected impurities is provided through the bottom of the sealed container 20a. Further, an air diffuser 26 connected to the air washing tube 20d, a backwash water introduction part 20e, and a washing drainage part 20f are provided below the sealed container 20a.

  The raw water inflow part 20b provided above the sealed container 20a is connected to the water intake part 10 via the raw water pump 71 and the path 76, and the filtered water outlet part 20c provided below the sealed container 20a is connected to the path 77. And connected to the upper part of the biofilm reactor 30 via a liquid feed valve. The raw water inflow portion 20b is provided in a state where the scraper 24 can be rotated by the flow of raw water introduced from the raw water inflow portion 20b into the sealed container 20a. For example, when the sealed container 20a is cylindrical, the swirl flow is formed in the sealed container 20a by providing the raw water inflow portion 20b so that the raw water flows in the tangential direction at the upper part of the sealed container 20a. The scraper 24 can be rotated by the flow.

  The scraper 24 is configured by attaching a plurality of wing portions 24b formed obliquely radially along the upper surface of the screen 21 to a rotary support shaft 24a inserted at the upper end of the screen waste discharging portion 25. As a result of rotation, the foreign matter captured by the screen 21 is scraped to the center side. In addition, a monitoring window 27, an intake / exhaust pipe 28, and a level sensor 29 are provided on the ceiling of the sealed container 20a.

  The filter medium support plate 22 is formed of a punching metal having a plurality of holes having a diameter of about 3 mm or a wedge wire screen. Any filter medium 23 filled between the screen 21 and the filter medium support plate 22 can be used according to the properties of the raw water, and any size and shape can be used. Nonwoven fabric can be used. In addition, the air diffuser 26 is provided in a ring shape around the screen waste discharging portion 25 on the upper surface or the lower surface of the filter medium support plate 22.

  Air is supplied to the air washing tube 20d from the air washing blower 74 through a path 78a, and the backwash water introduction unit 20e is supplied with backwash water from the chlorine mixing tank 50 by the backwash pump 73. Is supplied via the path 79 and the backwash valve 79a. Further, the foreign matter captured by the screen 21 is returned to the water intake unit 10 from the screen debris discharge unit 25 through the path 80 and the screen debris discharge valve 80a, and the washing wastewater is also washed into the washing wastewater discharge unit 20f. Then, the water is returned to the water intake section 10 through the path 81 and the washing drain valve 81a.

  In addition, when raw | natural water contains a lot of foreign substances, the discharge frequency to the water intake part 10 can be decreased by providing a storage part in the lower end part of the screen waste discharge part 25. FIG.

  The biofilm reactor 30 is a fluidized bed type, and, as shown in FIG. 3, a biocarrier 32 is filled between carrier support plates 31 and 31 provided in the upper part and the lower part of the sealed container 30a, respectively. Biologically treated water from which the filtered water inflow portion 30b into which the filtered water filtered by the prefiltration device 20 flows above the carrier support plate 31 is derived from the lower carrier support plate 31 and which has been biologically treated. Each of the derivation units 30c is provided, and an air diffuser 33 for ejecting air for bringing the biological carrier 32 into a fluid state is provided in the lower part of the sealed container 30a.

  The filtered water inflow portion 30b of the sealed container 30a is connected to the prefiltration device 20 via the path 77, and the biologically treated water outlet 30c is connected to the postfiltration device 40 via the path 82 and the biologically treated water outlet valve 82a. It is connected. A monitoring window 34, an exhaust valve 35, a back pressure valve 36, and a level sensor 37 are provided on the ceiling of the sealed container 30a. The back pressure valve 36 maintains an internal pressure of about 30 kPa in the sealed container 30a. In addition, the exhaust valve 35 can be used for intake and exhaust. Further, the water level is detected by the level sensor 37, and the exhaust valve 35 is opened and closed in accordance with the detected water level so as to keep the water level constant.

  A drain discharge part 30d is provided in the lower part of the sealed container 30a, and the drain discharge part 30d and the biologically treated water outlet part 30c are switched by an opening / closing operation of the drain outlet valve 30e and the biologically treated water outlet valve 82a, The biologically treated water is sent to the post filtration device 40 via the path 82. The air diffuser 33 is provided on the upper surface or the lower surface of the lower carrier support plate 31, and the air diffuser 33 is connected to the air diffuser 75 provided below the sealed container 30a. Air is supplied from the trachea 30f.

  Each carrier support plate 31 is formed of a punching metal having a plurality of holes having a diameter of about 8 mm. The biological carrier 32 can be arbitrarily selected from various carriers having a specific gravity of about 1 and a size of about 3 to 20 mm. For example, the biological carrier 32 is made of a foamed polypropylene formed in a hollow cylindrical shape having a diameter of about 10 mm and a length of about 10 mm. Can be used in the range of 0.95 to 1.05. Furthermore, by setting the filling amount of the biological carrier 32 to about 70 to 80% of the fluidized layer, friction between the carriers occurs, and the enlargement of the biological film can be prevented. The collision of the carrier support plate 31 with the carrier support plate 31 can also be prevented. Further, the carrier support plate 31 can be provided so as to cover each of the inflow part and the outflow part to the closed container 30a without providing the inside of the closed container 30a vertically. For example, by attaching a cylindrical body or the like formed of punching metal to the tip of the filtrate water inflow portion 30b, a biological support from the filtrate water inflow portion 30b can be obtained without providing a carrier support plate on the entire upper surface inside the sealed container 30a. The outflow of the carrier 32 can be prevented.

  In this embodiment, the biofilm reactor 30 is a downward flow system in which the filtered water inflow portion 30b is provided in the upper portion and the biological treated water outlet portion 30c is provided in the lower portion. It is also possible to employ an upward flow type biofilm reactor provided with a filtrate water inflow portion 30b and a biologically treated water outlet portion 30c above the upper carrier support plate 31, respectively.

  As shown in FIG. 4, the post-filtration device 40 includes a sealed container 40a, a screen 41 provided above the inside of the sealed container 40a, and a biologically treated water inflow portion 40b provided above the screen 41. The filter medium support plate 42 having a water flow structure provided below the inside of the sealed container 40 a, the filtered water outlet 40 c provided below the filter medium support plate 42, and between the filter medium support plate 42 and the screen 41. Is attached to the rotary shaft 44a of the screw ribbon type agitator 44, and is in sliding contact with the upper surface of the screen 41. A scraper 45 for scraping off the foreign matter captured by the screen 41, a screen waste discharging portion 40d provided around the screen 41, and a lower portion of the sealed container 40a. Backwash water inlet part 40e and is, and a detergent drain discharge portion 40f.

  The biologically treated water inflow part 40b provided above the sealed container 40a is connected to the biofilm reactor 30 via the path 82, and the filtered water outlet part 40c provided below the sealed container 40a is connected to the path 83. And the chlorine mixing tank 50 are connected to each other through a liquid feed valve. A suction / exhaust pipe 46, a level sensor 47, and a drive device 48 for a screw ribbon stirrer 44 are provided on the ceiling of the closed vessel 40a. The drive device 48 is connected to the closed vessel 40a via a swivel joint 49. A rotating shaft 44a protruding inward is connected to the swivel joint 49, and an air washing tube 78b for supplying air to the rotating shaft 44a is connected to the swivel joint 49. Further, the backwashing water introduction part 40e and the washing drainage discharge part 40f provided at the lower part of the sealed container 40a are switched by switching the opening and closing of the discharge valve 40g and the introduction valve 40h. In addition, the chlorine waste tank 50 is supplied from the chlorine mixing tank 50 through the backwash pump 73, and the cleaning wastewater is returned to the water intake unit 10 through the cleaning drainage discharge unit 40 f, the discharge valve 40 g and the path 85.

  The rotating shaft 44a of the screw ribbon stirrer 44 is formed by a hollow member having an air passage, and a plurality of screw support members 44b protrude in the radial direction from the peripheral wall of the rotating shaft 44a to support the screw ribbon 44c. Yes. The screw support member 44b is formed by a hollow member having an air passage communicating with the air passage of the rotating shaft 44a inside, and each air is connected to the lower and side portions of the screw support member 44b from the swivel joint 49. A plurality of air diffusion holes 44d for ejecting air supplied through the passage are provided. That is, the screw ribbon stirrer 44 serves as both a stirring unit that stirs the filter medium 43 with the rotating screw ribbon 44c and a diffused air supply unit that ejects air for washing from the diffuser holes 44d. In addition, it is also possible to make it the state which inserted the air washing pipe 78b upwards without the swivel joint in the center of the lower end part of the rotating shaft 44a, and, thereby, the connection of the air washing pipe 78b and the rotating shaft 44a. The structure can be simplified.

  The screen 41 is formed in a conical shape with a central portion protruding toward the ceiling portion of the sealed container 40a, and an insertion hole for the rotating shaft 44a is formed at the center. In addition, a concave groove 41a is formed on the outer periphery of the screen 41 for guiding foreign substances to the screen waste discharging portion 40d. The foreign matter captured by the screen 41 is returned to the water intake unit 10 through the concave groove 41a, the screen waste discharging unit 40d, the path 86, and the discharge valve 86a. Moreover, the filter medium 43 used for the post-filter apparatus 40 can use the same thing as the filter medium 23 used for the pre-filter apparatus 20, for example, the said nonwoven fabric can be used.

  The chlorine mixing tank 50 is a well-known tank equipped with a storage tank 50a, a stirring device 50b, and a chlorine storage tank 50c, and the treated water subjected to the chlorine treatment is introduced into the water supply device 60 through the water supply pump 72 and the path 87. The liquid is fed from the water supply device 60 to the path 88. A part of the treated water in the chlorine mixing tank 50 is sent to the pre-filtration device 20 and the post-filtration device 40 via the backwash pump 73 and used as backwash water.

  When the raw water is treated using the wastewater treatment device 1 formed in this way, first, the liquid feeding valve of the pre-filtration device 20 is opened, the intake / exhaust valve is closed, the flush valve is closed, and the screen waste discharge valve 80a. Is appropriately opened and closed. The raw water is pumped up from the water intake unit 10 by the raw water pump 71 and is supplied to the raw water inflow unit 20 b of the pre-filtration device 20 through the path 76. The raw water that has flowed into the sealed container 20a from the raw water inflow portion 20b flows into the sealed container 20a and flows, for example, in the tangential direction of the cylindrical sealed container 20a to form a swirling flow, and the scraper 24 is rotated. Relatively large contaminants in the raw water are captured on the upper surface of the screen 21 as the raw water passes through the screen 21. The trapped foreign matter is scraped to the center by the scraper 24, flows down in the screen dust discharge portion 25, and is discharged from the screen dust discharge portion 25 when the screen dust discharge valve 80a is opened. Returned to the water intake 10. The screen debris discharge valve 80a can be opened and closed by a differential pressure at the timer or the screen 21. The raw water that has passed through the screen 21 passes through the layer of the filter medium 23 packed between the screen 21 and the filter medium support plate 22, whereby fine suspended components in the raw water are captured, and the water supply pressure from the raw water pump 71. Is sent from the filtered water outlet 20c to the biofilm reactor 30 via the path 77.

  Moreover, the washing | cleaning process of the prefiltration apparatus 20 is started by the raise of a timer or filtration resistance (differential pressure of the raw | natural water inflow part 20b and the filtered water derivation | leading-out part 20c). In the cleaning process, first, the raw water pump 71 is stopped, the liquid supply valve is closed, the screen sensor drainage valve 80a is opened while the water level in the container is measured by the level sensor 29, and the intake / exhaust pipe 28 is opened. The water level is lowered until the space of about 200 mm is formed in the upper part of the sealed container 20a, and the screen waste valve 80a is closed. Next, the air washing valve of the path 78 is opened and the air washing blower 74 is operated to perform air washing for about 3 minutes at an air washing speed of 2 m / min, for example. Next, the intake / exhaust valve is closed, the flush valve is opened, the screen waste valve 80a and the flush drain valve 81a are opened, and the flush blower 74 is drained while operating. Further, the air washing blower 74 is operated with the intake / exhaust valve, the air washing valve, the screen waste discharge valve 80a and the washing drain valve 81a open and the liquid feeding valve is closed, and the backwash pump 73 is washed with water, for example. The operation is performed at a speed of 1 m / min for about 4 minutes, and the prefiltration device 20 is washed with air and backwashed. When such a cleaning process is completed, the filtration process is restarted after filling with water and allowing to stand for a predetermined time.

  In the filtration step in the pre-filtration device 20, the raw water inflow is made tangential to the airtight container 20a, so that the scraper 24 is rotated to scrape the screen dust, and the screen waste discharging portion 25 from the screen 21 formed in a hopper shape. Therefore, stable filtration can be performed even if a large amount of coarse impurities flow in. In addition, you may make it rotate the scraper 24 suitably with drive devices, such as a motor, without rotating with the flow of raw | natural water. Moreover, by forming the filter medium 23 with a nonwoven fabric having a large amount of SS retention, the filtration duration time can be increased and high-speed filtration is possible. Furthermore, by making the pre-filtration device 20 have a hermetically sealed structure, the air washing blower 74 can perform the air washing and draining in a short time.

  The filtered water filtered by the prefiltration device 20 is sent via the path 77 to the filtered water inflow portion 30b of the biofilm reactor 30 with the drain discharge valve 30e closed and the biological treated water outlet valve 82a opened. The biofilm reactor 30 keeps the inside of the sealed container 30a at an internal pressure of about 30 kPa by opening and closing the back pressure valve 36, and keeping the water level in the container at a predetermined water level by opening the exhaust valve 35 as necessary. It is. Further, air is supplied from the diffuser blower 75 to the biological carrier 32 through the diffuser tube 30 f and the diffuser means 33.

  The filtered water filtered by the pre-filtration device 20 passes through the layer of the biological carrier 32 packed between the carrier support plates 31 and 31, is biologically processed, and is led out from the biologically treated water outlet 30c. Further, the drain can be discharged by opening the drain discharge valve 30e and closing the filtered water outlet valve 82a as necessary when the waste water treatment apparatus is stopped.

  In this biofilm reactor 30, since the biocarrier 32 having a specific gravity of about 1 is used, the biocarrier 32 flows well by aeration and maintains a highly active filter bed while preventing clogging of the filter bed. And it is not necessary to wash the filter bed. Further, the carrier support plates 31, 31 are rubbed by the flow of the biological carrier 32, and the blockage of the carrier support plates 31, 31 can be effectively prevented. Furthermore, since the inside of the sealed container 30a is maintained at 30 kPa, the biologically treated water can be satisfactorily supplied to the subsequent post-filtration device 40, and since it is aerated under pressure, the water depth is reduced. Also, the air dissolution efficiency can be increased.

  The biologically treated water is derived from the biologically treated water deriving unit 30c, and after the discharge valve 40g and the introducing valve 40h are closed and the liquid feeding valve is opened, the biologically treated water is introduced into the filtered water inflow portion 40b of the filtration device 40 via the path 82. The When the biologically treated water flowing in from the filtered water inflow portion 40b passes through the screen 41, contaminants are captured, and by passing through the layer of the filter medium 43 filled between the screen 41 and the filter medium support plate 42, Suspended components are filtered off.

  Moreover, the washing | cleaning process of the post-filtration apparatus 40 is started by the raise of a timer or filtration resistance (differential pressure of the filtrate water inflow part 40b and the filtrate water extraction part 40c). In the washing process, the liquid feed from the biologically treated water outlet 30c is stopped, the screen waste discharge valve 86a is opened, the inside of the container is set to the empty flush water level by the level sensor 47, the discharge valve 86a is closed, The intake / exhaust valve of the exhaust pipe 46 is opened, the air wash valve of the air washing pipe 78b is opened, and the air washing blower 74 and the drive device 48 of the screw ribbon stirrer 44 are operated. The rotation speed of the screw ribbon type agitator 44 is set to about 1 to 20 revolutions per minute, and air is washed by sending air to the filter medium 43 from the plurality of air diffusion holes 44d of the screw ribbon type agitator 44 while stirring the filter medium 43. . Further, the intake / exhaust valve, the air washing valve, the screen waste discharge valve 86a and the discharge valve 40g are opened, the liquid supply valve in the passage 82 is closed, the air washing blower 74 and the backwash pump 73 are operated, and air washing is performed. Backwash. In addition, the scraper 45 rotates with the rotation of the screw ribbon stirrer 44, and the foreign matter captured by the screen 41 is collected in the concave groove 41a on the outer peripheral side, and is passed through the path 86 from the screen debris discharge part 40d. Returned to the water intake 10. When such a cleaning process is completed, the filtration process is restarted after filling with water and allowing to stand for a predetermined time.

  As described above, in the post-filter device 40, the air is supplied to the rotary shaft 44a while rotating the screw ribbon stirrer 44, and the air is blown out from the air diffusion holes 44d of the screw support member 44b, whereby the horizontal direction and the vertical direction. In combination with the effect of stirring, the filter medium 43 can be effectively washed with a small amount of air. In addition, since the scraper 45 is rotated together with the rotating shaft 44a, the screen 41 can be prevented from being clogged and a stable filtration operation can be performed even if a large amount of foreign matter flows in. In addition, since it has a sealed structure, it can be drained for a short time and reliably by the air-washing blower 74.

  The air diffusion holes 44d do not need to be provided in all the screw support members 44b, and a sufficient effect can be obtained even if the air diffusion holes 44d are provided only in the lowest screw support member 44b. Further, if necessary, a pipe having the same shape as that of the screw support member 44b is attached to a symmetrical position across the rotation shaft 44a at the same horizontal level as the one screw support member 44b at the lowermost portion, and an air diffuser hole 44d is provided here. Can also be provided. Further, it is possible to perform air cleaning of the filter medium support plate 42 by projecting the rotating shaft 44a to the lower side of the filter medium support plate 42 and attaching a tube having a diffuser hole 44d in the horizontal direction. However, since the liquid depths in the screw support members 44b are different from each other, it is possible to provide a pressure adjusting device at the base of the screw support member 44b so that air can be uniformly diffused from the air diffusion holes 44d of the upper and lower screw support members 44b. It is also possible to perform adjustment such as increasing the amount of air diffused from the lower air diffuser hole 44d as compared with the amount of air diffused from the upper air diffuser hole 44d by the pressure adjusting device.

  Furthermore, it is preferable to provide a check valve at the base of the screw support member 44b so that the liquid in the container does not enter into the rotating shaft 44a. A pressure regulating device having the function of a check valve is used as the pressure regulating device. It can also be used. Further, the air diffusion hole 44d may be a hole having a diameter of about 1 to 5 mm, but can also be formed by a slit, and an air diffusion device having a check valve function can be attached to the air diffusion hole 44d.

  The filtered water filtered by the post-filter device 40 is sent to the chlorine mixing tank 50 through the path 83 and together with a chlorine agent such as an aqueous sodium hypochlorite solution injected from the chlorine storage tank 50c by the chlorine injection pump 50d. , Well mixed with the stirring device 50b. The chlorinated water is introduced into the water supply device 60 through the water supply pump 72 and the path 87, the pressure is adjusted by the pressure adjusting compressor 60a, and the processed water is sent to the path 88.

  By forming the wastewater treatment apparatus of the present invention as described above, the structure of the pre-filtration apparatus 20, the biofilm reactor 30, and the post-filtration apparatus 40 can be simplified. If the amount of treated water is 20 to 100 m3 / day, it is compact. In addition, an inexpensive device can be provided. Further, since raw water can be sequentially supplied from the pre-filtration device 20 to the post-filtration device 40 via the biofilm reactor 30 at the water supply pressure of the raw water pump 71, it is not necessary to secure a head for water supply to the post-process. Can be kept low, for example, 3 m or less. As a result, the entire waste water treatment apparatus can be manufactured at the factory and transported to the site as it is, so that the construction period can be shortened and the manufacturing cost can be reduced.

  Further, since the raw water is fed from the pre-filtration device 20 to the chlorine mixing tank 50 by the pressure of the raw water pump 71, a relay tank and a relay pump are not required, and control is facilitated, and a waste water treatment apparatus. Can be made compact, and an in-vehicle device can also be obtained. Thereby, it can be employed for relatively short-term use as a purification device for rivers, lakes, ponds in parks, etc., or as a muddy water treatment during drought.

  In addition, when used for producing miscellaneous water at a sewage relay pump station, there is no problem even if the wastewater discharged by the washing operation of the filtration device is returned to the intake section where the inflowing sewage flows, In the case of performing purification and muddy water treatment, it is preferable to add a sludge treatment device for temporarily storing washing wastewater and performing coagulation sedimentation, dehydration, and the like. It can also be applied to miscellaneous water production and wastewater treatment in buildings and factories.

  The waste water treatment apparatus of the present invention exemplified in this embodiment preferably controls the operation of the raw water pump according to the water level of the chlorine mixing tank, and operates each apparatus in accordance with the operation of the raw water pump. In addition, during periods of nighttime outages, days, national holidays, or rest periods due to consecutive holidays, water is automatically drained by intermittent operation in consideration of maintaining the activity of the bioreactor, preventing freezing, and sludge decay. It is preferable to incorporate a standby mode. In the standby mode, the aeration amount of the biofilm reactor can be narrowed down to about one-third of the normal amount to reduce the running cost.

  Further, the screw ribbon in the post-filter device is not limited to a single structure but may be a double structure. When the apparatus becomes large, it is effective to provide a plurality of ribbons inside and outside. Further, by supplying chemical liquid or steam to the rotating shaft, chemical liquid cleaning, steam cleaning or the like can be performed, and the chemical liquid or heat can be transmitted effectively, and the sterilization effect can be enhanced.

  Further, in the sterilization treatment, the sterilization effect is sustained by residual chlorine as a method of injecting a chlorine agent such as an aqueous sodium hypochlorite solution, but UV sterilization or the like may be performed depending on the purpose of use.

  In addition, when the raw water taken from the water intake unit 10 does not contain impurities or suspended substances, the prefiltration device 20 has almost no influence on the operation of the biofilm reactor 30 even if the prefiltration device 20 is omitted. The waste water treatment apparatus can be further reduced in size and simplified by omitting 20. In addition, there is no particular limitation on the height of the apparatus, and when the appropriate water head is obtained by forming each container high, it is necessary to form the prefiltration apparatus 20, the biofilm reactor 30, and the postfiltration apparatus 40 with a sealed container. Alternatively, the upper part of the container may be opened. Moreover, you may make it rotate the scraper 24 of the prefiltration apparatus 20 with drive devices, such as a motor.

  FIG. 5 is a longitudinal sectional view showing another embodiment of a filtration device used as a post-filtration device. In the following description, the same components as those shown in the above-described embodiment are given the same reference numerals, and detailed description thereof is omitted.

  The filtration device shown in this embodiment is an example applied to a sand filtration device using sand having a large specific gravity as the filter medium 43. When the specific gravity of the filter medium 43 is large, it is only necessary to provide a drain trough 41b and a drain pipe 41c for discharging washing waste water above the filter medium filling part in the container 40a, and a screen and a filter medium support plate can be omitted. . Although not shown in the drawings, when a non-woven fabric having a specific gravity of about 1 is used as the filter medium 43, a filter medium support plate is provided at an appropriate position above the container so that the filter medium 43 does not flow out of the drain trough 41b and the drain pipe 41c. It should be provided.

  6 and 7 are sectional plan views of the pre-filtration device and the post-filtration device. FIG. 6 shows an example in which a cylindrical container is used as the filtration container 90a of the filtration device 90, and FIG. Examples using a rectangular tube-shaped filtration container 90b are shown. Thus, as the filtration container of the pre-filtration device or the post-filtration device, those having various shapes including a cylindrical shape and a rectangular tube shape can be arbitrarily used. At this time, conditions such as the amount of processing, the type of filter medium, the height of the filtration containers 90a and 90b, and the diameter of the screw ribbon type agitator and the filtration containers 90a and 90b in the post-filtration apparatus equipped with a screw ribbon type agitator. By appropriately setting the distance from the inner surface, the same filtration performance can be obtained regardless of the shape of the filtration container. Further, in the case of a rectangular tube-shaped filtration container, a partition member may be provided at the container corner portion as necessary to bring the horizontal cross-sectional shape closer to a cylindrical shape.

  FIG. 8 shows an example in which a plurality of filtration devices are installed in the filtration pond. Large-scale sewage treatment plants in large cities often have concrete filtration ponds with a horizontal cross-sectional area of 50 m2 (7.1 m × 7.1 m) as rapid sand filtration facilities. When applying the above-described post-filtration device 40 to such a filtration basin 91, the diameter of the screw ribbon stirrer 44 is about 2800 mm at the maximum in consideration of conveyance on public roads. The partition plate 92 is divided into four sections 93, and in each section 93, equipment necessary for a post-filtration device such as a screw ribbon stirrer 44 is installed. The partition plate 92 may be in a state in which each partition 93 is completely partitioned and each partition 93 is made independent, but by forming the partition plate 92 with a porous plate or a net having water permeability without passing the filter medium, The distribution of the filter medium can be averaged and the filtration process in the filtration basin 91 can be performed stably. The partition plate 92 can be omitted depending on conditions such as the type of filter medium and the height of the filter bed. In addition, the rotational direction of the adjacent screw ribbon stirrer 44 can be set in the reverse direction in consideration of the flow of water in the filtration basin 91.

  As shown in FIG. 8, in the case of equipment having a plurality of filter basins 91, the filter medium is washed one by one in order. The frequency of washing varies depending on the conditions such as the properties of raw water and the filtration rate, but it is usually about 2 to 4 times a day. Therefore, the washing equipment such as backwash pumps and empty washing blowers is used for 4 to 8 ponds. It is sufficient to provide a complete set. If this is one line, the amount of treated water per line will be 200,000 to 400,000 m3 / day. Since the treatment scale of a sewage treatment plant in a large city is about 200,000 to 1,000,000 m3 / day, it can be handled in 1 to 3 systems.

  In addition, although the example which applied the post filtration apparatus 40 was given in FIG. 8, the above-mentioned pre filtration apparatus 20 is applicable similarly. In this way, the filtration device of the present invention can be applied to a filter basin of an existing concrete frame by dividing the inside of the filter basin into an appropriate size by means of a partition plate. The filtration function of existing equipment can be improved at low cost, and the amount of treated water can be increased.

  DESCRIPTION OF SYMBOLS 1 ... Waste water treatment apparatus, 10 ... Water intake part, 20 ... Pre-filtration apparatus, 20a ... Sealed container, 20b ... Raw water inflow part, 20c ... Filtrated water outlet part, 21 ... Screen, 22 ... Filter medium support plate, 23 ... Filter medium, 24 ... scraper, 30 ... biofilm reactor, 30a ... sealed vessel, 30b ... filtered water inflow part, 30c ... biological treated water outlet part, 31 ... carrier support plate, 32 ... biological carrier, 33 ... air diffuser, 40 ... post-filtration 40a ... Filtration water inflow part, 40c ... Filtration outlet part, 41 ... Screen, 42 ... Filter medium support plate, 43 ... Filter medium, 44 ... Screw ribbon stirrer, 45 ... Scraper, 50 ... Chlorine mixing tank , 90a, 90b ... Filtration container, 91 ... Filtration pond, 92 ... Partition plate

Claims (2)

  A wastewater treatment apparatus comprising: a biofilm reactor that performs biological treatment by bringing raw water into contact with an aerobic microorganism carrier; and a post-filtration device that performs filtration treatment of biologically treated water derived from the biofilm reactor. The carrier support plate provided above and below the inside of the sealed container, the biological carrier having a specific gravity of 0.95 to 1.05 filled between both carrier support plates, and the upper carrier support plate, A fluidized bed biofilm reactor comprising a raw water inflow portion and a treated water lead-out portion respectively provided below the upper and lower carrier support plates, and an aeration means for agitating the biological carrier by aeration. The post-filter device includes a filter medium support plate provided below the inside of the sealed filter container, a filter medium filled in the upper part of the filter medium support plate, and a screw for stirring the filter medium provided in the center of the filter container A screw-type stirrer, a biologically treated water inflow portion provided above the filter material filling portion, a backwash water introduction portion and a wash drainage portion provided below the filtration container, and the screw ribbon The mold stirrer includes a rotating shaft having an air passage therein, and a plurality of screws having an air passage internally projecting from a peripheral wall of the rotating shaft to support the screw ribbon and communicating with the air passage of the rotating shaft. A support member, a plurality of air diffuser holes provided in the screw support member, and air diffused from the air diffuser holes through the air passage of the screw support member. The wastewater treatment apparatus comprising: an air-air supply means, wherein the raw water is pumped by a raw water pump and is sequentially supplied to the biofilm reactor and the post-filtration device.   2. The wastewater treatment apparatus according to claim 1, wherein the biofilm reactor includes a pre-filtration device that performs a raw water filtration process in a front stage of the biofilm reactor, and the pre-filtration device is disposed above and inside a sealed filtration container. A screen provided; a filter medium support plate provided below the inside of the filtration container; a filter medium filled between the filter medium support plate and the screen; and a scraper for scraping off foreign matter trapped in the screen. And a screen debris discharge portion for discharging foreign matter scraped off by the scraper to the outside of the filtration container, a raw water inflow portion provided above the screen, and a filtered water derivation provided below the filter medium support plate And a diffuser provided below the filtration container, a backwash water introduction unit, and a washing drainage discharge unit, and the raw water is pumped by a raw water pump and is sent from the prefiltration device to the living organism. Wastewater treatment apparatus characterized by being sequentially supplied to the after filtration apparatus through the reactor.

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