JPS61291099A - Downward flow type biological membrane purifying apparatus - Google Patents

Abstract

PURPOSE:To simultaneously perform the biological treatment of raw water and the washing of a filter material, by mounting a purifying tank, an air diffuser and a water collection chamber and arranging an air lift pipe in the purifying tank in the vertical direction to suck a filter material having a solid substance adhered thereto from the lower end of the air lift pipe. CONSTITUTION:The raw water supplied from the upper part of a purifying tank 23 by an inflow pipe passes through a filter tank 22a. The SS-component and BOD component contained in the raw water receive oxidative decomposition by the aerobic biological treatment of bacteria and a solid substance is adhered and accumulated to the surface of a filter material 22. The solid substance is collected on the surface of the filter material 22 or in the spaces of said filter material 22 and moves to the lower bed of the filter tank 22a in a collected state to be guided from an air lift pipe 27 to a separation apparatus 29. The raw water is downwardly flowed from the upper part of the purifying tank 23 by the suction force generated by an air lift apparatus 28 when passed through the filter tank 22a while purified and treated water is sucked in a water gathering chamber 25.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a downward flow type biofilm purification device that simultaneously and continuously performs biological treatment of raw water and cleaning of filter media.

(b) Conventional technology and problems Conventionally, water contaminated with slag materials has been treated with microorganisms (@
One of the methods for purifying waste water by JM is a biofilm purification device that attaches microorganisms to solid particles and brings them into contact with pollutants in the raw wastewater to be purified by aerobic digestion of the raw wastewater. A typical example of this biofilm purification device is a downward flow type biofilm purification device in which raw wastewater flows downward from the top of the device.

This downward flow type biofilm purification device has been developed recently, and for example, the one shown in FIG. 11 is known.

As shown in the figure, a reaction tank 1 is partitioned by a floor plate 2, and a raw water treatment chamber 3 above the floor plate 2 has a filter material (for example, anthrazite, activated carbon, lightweight aggregate, etc. with a particle size of about 2 to 10 mm) 4. is filled. At the bottom of the floorboard 2 is a raw water treatment chamber 3.
A water collection chamber 5 is provided to collect treated water that has been subjected to biological treatment. A water collection strainer 6 is provided on the floor plate 2 to collect treated water treated in the raw water treatment chamber 3. The raw water treatment chamber 3 is provided with an aeration device 8 that blows air necessary for biological treatment into the raw water using an aeration blower 7.

A treated water tank 9 is provided separately from the reaction tank 1, and a treated water pipe 10 through which treated water from the water collection chamber 5 passes is provided between the treated water tank 9 and the reaction tank 1. In order to wash the filter medium 4 to which solid matter has adhered, a backwash pump 11. Backwash blower 12. A siphon pipe 13 is connected to each treatment water tank 9. Water collection room 5. It is located in raw water treatment room 3.

Raw water flowing from the upper part of the raw water treatment chamber 3 passes through the filter medium 4, is subjected to biological treatment, and enters the water collection chamber 5 through the water collection strainer 6. The treated water collected in the water collection chamber 5 passes through the treated water pipe 10 and is stored in the treated water tank 9 and then discharged. During this time,
When the raw water passes through the filter medium 4 in the raw water treatment chamber 3, it is purified by the action of microorganisms attached to the surface of the filter medium 4. SS components and BOI components contained in the raw water are deposited on the surface of the filter medium 4 through biological treatment, and solid matter accumulates on the filter medium 4. For this reason, the spaces between the filter media 4 become clogged, and the resistance to passage of raw water increases. In this manner, the filter medium 4 is backwashed because it is necessary to remove solid matter adhering to the filter medium 4.

That is, a large amount of air is blown into the raw water treatment chamber 3 through the water collection chamber 5 from the backwash blower 12 to separate solids from the filter medium 4, and then the treated water is sent to the raw water treatment chamber 3 by the backwash pump 11.
The solids are discharged from the upper part of the raw water treatment chamber 3 to the outside of the reaction tank 1 via the cybon pipe 13.

However, in such a downward flow type biofilm purification device, firstly, the purification function of the raw water is stopped during the backwashing process of the filter medium 4. That is, the purification of raw water and the cleaning of the filter medium 4 by backwashing cannot be carried out simultaneously and continuously, and the operating rate of the purification device decreases. For this reason, if it is attempted to simultaneously and continuously perform the purification treatment of the raw water and the cleaning treatment of the filter medium 4, a plurality of such purification devices will be required, which will inevitably increase the size of the device.

Second, the filter medium 4 is not cleaned during the purification of the raw water. Therefore, after cleaning the filter medium 4, solid matter adheres to the filter medium 4 over time, and the purification rate by biological treatment decreases.

Thirdly, a large amount of air is required for backwashing the filter medium 4.

Since a large amount of backwash water is required, a backwash blower 12, a backwash pump 11. A large-scale treatment water tank9 was required.

Fourth, as mentioned above, since the purification rate by biological treatment is low, a large amount of filter media 4 is required, and furthermore, a water collection chamber 5 is also required for backwashing of the filter media 4. 1 reaction tank was required.

(C) Purpose of the Invention The present invention has been made to solve the above-mentioned problems, and its purpose is to enable biological treatment of raw water and cleaning of filter media to be carried out simultaneously and continuously. Backwash blower increases purification rate.

The purpose of the present invention is to provide a downward flow type biofilm purification device in which a backwash pump and a large-scale treatment water tank are eliminated and the reaction tank is reduced in size.

Structure of the Invention In order to achieve the above object, the present invention comprises a septic tank filled with a filter medium, an aeration device provided in the septic tank to supply oxygen, and a water collection chamber for collecting biologically treated treated water. A treatment water pipe that communicates with the water collection chamber and an air lift pipe are placed vertically in the septic tank, and from the lower end of the air lift pipe, filter media with solids attached due to the biological treatment of raw water are sucked in, and the solids are removed from the filter media within the air lift pipe. An airlift device that lifts solids and filter media simultaneously while peeling them off, a separation device installed at the upper end of the airlift pipe that separates the filter media and solids and circulates the filter media into the septic tank, and a discharge pipe that discharges the solids from this separation device. It is composed of.

(E) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a downward flow type biofilm purification device according to a first embodiment of the present invention.

As shown in the figure, the downward flow type biofilm purification device 21 according to the present embodiment includes a septic tank 23 filled with a filter medium 22, and a septic tank 23 filled with a filter medium 22.
An air diffuser 24 installed inside the tank to supply oxygen, a water collection chamber 25 that collects biologically treated water, a treated water pipe 26 connected to the water collection room 25, and an air lift pipe 27 installed in the vertical direction of the septic tank 23. Placed under the air lift pipe 27 & 1i127a
Filter media 22 with solid matter attached to it through biological treatment of raw water
At the same time, the solid matter is removed from the filter medium 2 in the air lift pipe 27.
an air lift device 28 that simultaneously lifts the solids and the filter medium 22 while peeling them from the air lift pipe 27;
7b, a separation device 29 that separates the filter medium 22 and solid matter and circulates the filter medium 22 into the septic tank 23;
9 and a discharge pipe 30 for discharging solid matter.

As the filter medium 22, for example, anthracite, activated carbon, lightweight aggregate, etc. are used, and the particle size thereof is about 2 to 10 centimeters.

A filtration layer 22a is formed in the septic tank 23 by this filter material 22.
is formed. The bottom 23a of the septic tank 23 has a conical shape. This is to ensure that all of the filter medium 22 with solid matter attached to it is sucked into the air lift pipe 27 without stagnation.

The water collection chamber 25 is provided integrally with the air lift pipe 27 at a lower portion of the air lift pipe 27. The water collection chamber 25 is a bowl-shaped container having an opening 25a.

The water collection chamber 25 can also be a cup-shaped container with a polygonal cross section. The treated water pipe 26 is connected from the water collection chamber 25 to the septic tank 23.
The septic tank 23 is disposed outside the septic tank 23 by penetrating the bottom 23a thereof. The treated water collected in the water collection chamber 25 rises to the treated water tank 31 due to the water level difference. Air diffuser 2
4 is provided above the water collection chamber 25. Therefore, oxygen is evenly supplied to the filter medium 22, and microorganisms adhere to and grow on the surface of the filter medium 22. The air lift pipe 27 has its lower end 2
7a is located at the bottom 23a of the septic tank 23, and its upper end 27b is located at the top of the septic tank 23. An air device 28a that supplies air for air lift is connected to the lower end 27a of the air lift pipe 27 so as to form an L-shape with the air lift pipe 27. The separation device 29 has a mesh that does not allow the filter medium 22 to pass through, for example, a slit or a mesh.
It is composed of a truncated conical hollow structure 29a having a wire mesh-like inclined surface 29c such as a punch hole, and a shielding plate 29b. The shielding plate 29b is for allowing the filter medium 22 and solid matter to flow along the inclined surface 29c of the hollow structure 29a.

The shielding plate 29b has a cylindrical shape in consideration of maintenance and inspection. The amount of solids discharged from the discharge pipe 30 together with a portion of the treated water is determined by adjusting the amount of air in the air device 28a and separating device 29.
This can be done by changing the area of the wire mesh, installing a valve, etc. on the discharge pipe 30, etc.

The effects of this embodiment resulting from the above configuration will be described next.

The filter medium 22 filled in the septic tank 23 is equipped with an aeration bag Ft.
Aeration air is supplied by 24, and microorganisms are attached and grown on the surface of the filter medium 22. Raw water supplied from the upper part of the septic tank 23 through an inflow pipe (not shown) passes through the filtration ii 22 a.

SS components, BOD components, etc. contained in the raw water are oxidized and decomposed by aerobic biological treatment by microorganisms, and as a result, solid matter adheres and accumulates on the surface of the filter medium 22. The solids in the raw water and the solids generated by biological treatment are removed from the filter medium 22.
It is collected on the surface or between the filter media 22, moves to the lower layer of the filter N 22 a while being collected, and is led to the separation device 29 through the air lift pipe 27. Therefore, there is less solid matter mixed into the treated water, and a settling tank, which is required in normal contact oxidation methods, activated sludge methods, trickling filter methods, etc., is not required.

The raw water is purified as it passes through the filtration layer 22a, and flows downward from the upper part of the septic tank 23 due to the action of gravity and the suction force generated by the air lift device 28 to the lower end 27a of the air lift pipe 27. The treated water purified by the filtration layer 22a flows toward the bottom 23a of the septic tank 23, but since the water collection chamber 25 is provided at the bottom of the septic tank 23, a part of the treated water flows to the lower end 27a of the air lift pipe 27. The water is sucked into the water collection chamber 25, which is mostly a space.
be sucked into. At this time, if the water collection chamber 25 has an appropriate length of the side surface portion 25b and the treated water pipe inflow portion 26a is set at an appropriate height, there is no room for the filter medium 22 to enter the treated water pipe 26. The treated water stored in the water collection chamber 25 is guided into the treated water tank 31 via the treated water pipe 26 due to the difference in water level 6 On the other hand, the filter medium 22 with solid matter adhered to the air lift air blown from the air device 28a. As a result, the air is sucked in from the lower end 27a of the air lift pipe 27 and rises inside the air lift pipe 27. Filter medium 22.
Since a portion of the treated water, air, rises, solid matter adhering to the filter medium 22 is stirred and separated from the filter medium 22. This separated solid matter.

Filter medium 22. A portion of the treated water rises up the air lift pipe 27 and is discharged from the upper end 27b of the air lift pipe 27 to the separation device 29. At this time, the solid matter, filter medium 22, and part of the treated water (
This treated water (usually called backwash water) is blocked by the shielding plate 29b of the separation device 29 and flows along the inclined surface 29c of the hollow structure 29a. The filter medium 22 washed in the air lift pipe 27 is transferred to the wire mesh-like inclined surface 29C of the separation device 29.
is passed through a sieve and circulated into the septic tank 23.

The solids enter the hollow structure 29a of the separator 29 together with the backwash water. This solid matter becomes backwash waste water together with backwash water. This backwash waste water is discharged through a drain pipe 30.

The treatment of backwash wastewater discharged from the purification device 21 will be explained with reference to FIG.

The backwash wastewater is guided to a backwash wastewater sedimentation tank 33.

In the backwash wastewater sedimentation tank 33, the settled sludge in the backwash wastewater is treated as sludge bones at the discharge port 33 of the backwash wastewater sedimentation tank 33. +
6 backwash wastewater sedimentation basin 33
The supernatant water inside is supplied to the raw water tank 34. This supernatant water is circulated and supplied as raw water from the raw water tank 34 to the septic tank 23 together with the waste water supplied to the raw water tank 34.

According to the downward flow type biofilm purification device 21 having the above configuration, the following effects are produced.

First, the purification treatment of raw water and the cleaning treatment of the filter medium 22 within the air lift tube can be performed simultaneously and continuously. As a result, the operating rate of the downward flow biofilm purification device 21 according to the present invention is improved, and one device 21 can be used continuously without stopping the purification process, and there is no need to increase the size of the device. lost.

Second, as mentioned above, at the same time as the raw water is purified, the filter medium 22
A cleaning process is being carried out. Therefore, the washed filter +
The amount of solid matter adhering to A22 is small, so the purification rate by biological treatment is improved.

For example, in this embodiment, for a device whose BOD load was taken as shown in the table below, the quality of raw water was obtained as shown in the table below.

Thirdly, cleaning of the filter medium 22 is performed in the air lift tube 27, and the filter medium 22 is separated from solids in a separator 29,
The washed filter medium 22 is circulated into the septic tank 23. Therefore, there is no need for a backwash blower, a backwash pump, a large-scale treatment water tank, and the automatic valves attached thereto for cleaning the filter medium 22, which were required in the conventional example.

Fourthly, as mentioned above, since the purification rate by biological treatment is high, the amount of filter media 22 required for the raw water to be treated is reduced, and furthermore, the water collection chamber in the conventional example is not required. Therefore, the septic tank can also be made smaller.

Fifth, as a result of the solid matter and the filter medium 22 being sieved by the inclined surface 29c of the separator 29 such as a wire mesh, the solid matter enters the inside of the hollow structure 29a together with the backwash water and circulates into the septic tank 23. Never. Therefore, the possibility that solid matter will be mixed into the treated water in the septic tank 23 due to the separation device 29 is eliminated.

Sixthly, the filter medium 22 discharged from the upper end 27a of the air lift pipe 27 is circulated to the septic tank 23 while being rubbed against each other on the inclined surface 29c of the separation device 29.

Therefore, the solid matter is also separated from the filter medium 22 within the separator 29.

b Seventhly, in the separation device 29, the filter medium 22 and the solid matter are physically separated via the inclined surface 29C, such as a wire mesh, so that
It becomes possible to attach a vibration device to the separation device 29, and the separation speed can be increased.

Eighth, the filter medium 22 is a net-like inclined surface 29c of the separation device 29.
Since the solids are sieved by the filter, there is no possibility that the solids will be mixed into the hollow structure 29a, and the solids are circulated into the septic tank 23 without waste.

Ninth, a settling tank, which is required in the usual catalytic oxidation method, activated sludge method, trickling filter method, etc., is not required.

Next, a downward flow type biofilm purification device according to a second embodiment of the present invention will be explained with reference to FIG. 4.

As shown in the figure, the downward flow biofilm purification device 21A according to the present embodiment includes a septic tank 23A filled with a filter medium 22A, a diffuser W24A installed in the septic tank 23A to supply oxygen, and a biologically treated biofilm purifier 21A. Water collection chambers 25A and 25A that collect treated water
, 25A, 25A.

25A, treated water pipes 26A connected to each water collection chamber 25A, and five air lifts arranged in the vertical direction of the septic tank 23A, from each lower end 27b of each air lift pipe 27A to filter media to which solid matter has been attached due to biological treatment of raw water. 22A and solids are removed from the filter medium 22 in each air lift pipe 27A.
Air lift devices 28A, 28A, 28A that simultaneously lift solids and filter media 22A while separating them from A
, 28A, 28A' and each air lift pipe 27A
A separation device 29A is provided at each upper end 27C of the filter medium 22A to separate the solid matter from the filter medium 22A and circulate the filter medium 22A into the septic tank 23A.
, 29A, 29A, 29A, 29A and each separation device 29
It is composed of an exhaust pipe 30A for discharging solid matter from A and an exhaust pipe 30A.

According to the second embodiment, in addition to the effects of the first embodiment, it is possible to purify a large amount of raw water.

In addition, in the first embodiment, the intake port 26 of the treated water pipe 26
Although the pipe a is guided inside the water collection chamber 25, it is also possible to connect the treated water pipe 26 to the side surface 25a of the water collection chamber 25, as shown in FIG.

The second embodiment also specifically shows this aspect.

Further, according to the first embodiment and the second embodiment, the water collection chamber 25.2
5A and the air lift pipe 27.27A are integrated, but as shown in FIG. 6, the water collection chamber 25B is formed into a substantially doughnut-shaped space, and the air lift pipe 27 is placed in the center 35 of this doughnut-shaped space to collect water. It is also possible to arrange it separately from the chamber 25B. In this case, the treated water pipe 26 is connected to the septic tank 23 that forms the side surface of the water collection chamber 25B.

Furthermore, if there are many floating substances in the raw water and scum is generated, a scum removal nozzle 32 may be provided at the top of the septic tank 23, thereby making it possible to periodically discharge the scum. The scum after discharge is usually mixed with backwash wastewater and treated in a backwash wastewater sedimentation tank 33.

In addition, in this embodiment, the air lift pipe 27 is provided inside the septic tank 23, but its suction port is provided inside the septic tank 23, and it is constructed of an L-shaped pipe body and penetrates through the septic tank 23 to the outside of the septic tank. Furthermore, the decomposition device 29 is also installed in the septic tank 23.
It is also possible to arrange it outside.

Furthermore, in the first and second embodiments, the air device 28a that supplies air for air lift is the air lift pipe 27.
Air lift tube 27.27 at the lower end 27a, 27b of 27A
Although the air device 35 is connected to the air lift pipe 27, 27A so as to form a hook shape, as shown in FIG. Air is supplied from the most open end 35a of the air lift tube 27.27A.

In addition, as an embodiment in which the air device and air lift pipe are integrated,
Examples shown in FIGS. 8 to 9 are given.

That is, as shown in FIGS. 8 and 9, the air lift pipe 27
．． An air device 35A is arranged concentrically around the outer periphery of 27A. In this case, as shown in FIG.
It is also possible to provide an air supply port 37 in the middle part 36 of the vertical tube constituting the pipe.

(F) Effects of the Invention As described above, according to the present invention, firstly, biological treatment of raw water and cleaning of filter media can be carried out simultaneously and continuously, and secondly, biological treatment of raw water can be performed. Thirdly, there is no need for backwash blowers, backwash pumps, large-scale treatment water tanks, etc., fourthly, the septic tank can be made smaller, and fifthly, Sixthly, the separation device can also provide a force to separate the solids from the filter medium, and seventhly,
It is possible to attach a vibration device to the separation device, and the eighth
In addition, the filter media can be circulated into the septic tank without waste.
Ninthly, it is possible to eliminate the settling tank required in ordinary catalytic oxidation methods.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of a downward flow type biofilm purification device according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, and FIG. FIG. 4 is a cross-sectional configuration diagram of the downward flow type biofilm purification device according to the second embodiment of the present invention. FIG. 5 is a cross-sectional diagram showing another method of connecting treated water pipes. 6 is a sectional view showing another example of the water collection chamber, FIG. 7 is a sectional view showing another embodiment of the air device, FIG. 8 is a partial view showing still another embodiment of the air device, and FIG. 9 is a sectional view showing another embodiment of the air device. The figure is a cross-sectional view taken along line B-B in Figure 8, Figure 10 is an explanatory diagram explaining the air supply position in the air device, and Figure 11 is a cross-sectional diagram of a conventional downward flow type biofilm purification device. be. 21...Downward flow type biofilm purification device according to the first embodiment,
22... Filter medium, 22a... Filter layer, 23... Septic tank, 24... Air diffuser, 25... Water collection room, 25a.
... Opening section, 26 ... Treated water pipe, 26a ... Intake port, 27 ... Air lift pipe, 28 ... Air lift device, 29 ... Separation device, 29a ... Hollow structure section, 29
C... Inclined surface, 30... Drain pipe, 31... Treatment water tank. Figure 8 Figure 10 Figure 9 Figure 27, 27A

Claims (12)

[Claims] (1) A septic tank filled with filter media, an aeration device installed in the septic tank to supply oxygen, a water collection chamber for collecting biologically treated water, a treated water pipe communicating with the water collection room, and a vertical wall of the septic tank. An air lift device in which an air lift tube is disposed in the direction of the air lift tube, and the filter medium to which solid matter has adhered due to biological treatment of raw water is sucked in from the lower end of the air lift tube, and the solid matter and the filter medium are lifted simultaneously while peeling the solid matter from the filter medium within the air lift tube. , a downward-directing device comprising a separation device installed at the upper end of the air lift tube to separate the filter medium and solids and circulate the filter medium into the septic tank, and a discharge pipe to discharge the solids from the separation device. Flow-type biofilm purification device. (2) The downward flow type biofilm purification device according to claim 1, wherein the air lift pipe is provided in a septic tank. (3) The downward flow type biofilm purification device according to claim 2, wherein the air lift pipe and the water collection chamber are integrated. (4) The downward flow type biofilm purification device according to claim 2, wherein the air lift pipe and the water collection chamber are separate bodies. (5) The downward flow type biofilm purification device according to claim 1, wherein the air lift pipe is a straight pipe body, and the suction port thereof is provided in the septic tank. (6) The downward flow type biofilm purification device according to claim 1, wherein the air lift pipe is an L-shaped pipe body, and the suction port thereof is provided in the septic tank. (7) The downward flow type biofilm purification device according to claim 1, wherein the air device is configured separately from the air lift pipe and is connected to the lower end of the air lift pipe. (8) The downward flow biofilm purification device according to claim 1, wherein the air device is integrated with an air lift pipe. (9) The downward flow biofilm purification device according to claim 7, wherein the air device is arranged concentrically outside the air lift tube. (10) The water collection chamber is a bowl-shaped or cup-shaped container with a polygonal cross section and has an opening, and the opening faces downward and a treated water pipe is installed inside the bowl-shaped or polygonal cross-sectional cup-shaped container. 2. A downward flow type biofilm purification device according to claim 1, wherein the intake port is guided. (11) The downward flow according to claim 1, characterized in that the separation device is provided with a hollow structure having a wire mesh-like sloped surface having a mesh that does not allow the filter medium to pass through. Type biofilm purification device. (12) The downward flow type according to claim 1, characterized in that the separation device is provided with a hollow structure having an inclined surface having slit punch holes that do not allow the filter medium to pass through. Biofilm purification device.