JP2001286880A - Organism immobilizing carrier separation screen at sewage treating device and its replacement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a screen applicable even to a carrier having small particle size, to prevent the clogging of the screen by surely generating the upward stream of diffused air along the screen and also to make the replacement of a clogged screen easy. SOLUTION: An organism immobilizing carrier 2 is floated in the sewage to be treated in a reaction tank 1 and an organism immobilizing carrier separation screen 3 is provided at the outlet part of the reaction tank in order to separate the carrier from effluent while preventing the flowing out of the organism immobilizing carrier from the reaction tank. The organism immobilizing carrier separation screen 3 is constituted with a punching plate having many long holes. A material of the punching plate may be a material having large strength such as steel plate, and the long holes provided drillingly at the punching plate may be ellipse, rectangle, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sewage treatment apparatus using a biologically immobilized carrier for domestic wastewater treatment such as sewage treatment, industrial wastewater treatment or landfill leachate treatment, and more particularly, to a wastewater treatment apparatus for use in a reaction tank. The present invention relates to a biologically immobilized carrier separation screen provided at an outlet of a reaction vessel for preventing a biologically immobilized carrier floating in sewage to be treated from flowing out of the tank and separating the carrier from an effluent.

[0002]

2. Description of the Related Art Conventionally, in order to separate a biologically immobilized carrier from waste water, a wedge wire type screen in which a plate-like or rod-like steel material is assembled in a lattice shape at the outlet of a reaction tank, or a number of round holes are used. A perforated punching plate was provided.

[0003]

However, the screen of the wedge wire type requires a plate-shaped or rod-shaped steel material to be arranged at regular intervals in a grid-like structure, and the manufacturing process is complicated. Was. On the other hand, in a punching plate with a large number of round holes, the diameter of the hole needs to be smaller than the particle size of the biological immobilization carrier. There was a risk that the holes would be blocked by fibrous materials such as thread and lint. Therefore, a punching plate having such a round hole is
It was unsuitable for the use of small particle size carriers.

[0004] Air washing and mechanical washing with a brush or the like have been generally used as a washing mechanism for a biologically immobilized carrier separation screen having a closed hole. At the outlet of the reaction tank, an air diffuser is provided at the lower end on the upstream side of the carrier separation screen, separately from an air diffuser installed to supply oxygen into the reaction tank at the outlet of the reaction tank. I was However, in this method, the aeration is easily affected by the stirring flow in the reaction tank, and it is difficult to reliably generate an upward flow of the aeration along the screen and prevent the screen from being clogged.

[0005] To prevent clogging of the biologically immobilized carrier separation screen, there are air cleaning and mechanical cleaning as described above.
If the blockage cannot be resolved by these means,
It is necessary to remove firm deposits on the screen directly. In such a case, conventionally, a method of lowering the water level of the reaction tank to below the screen, exposing the screen on the water surface, and manually removing strong deposits has been generally used. However, this operation was extremely complicated, such as the need to stop the inflow of wastewater into the tank to be treated.

In view of the above, the present invention makes it possible to apply a screen to the use of a carrier having a small particle size and to surely generate an upward flow of diffused air along the screen. It is an object of the present invention to prevent a screen from being blocked and, in addition, to easily replace a closed screen.

[0007]

According to the present invention, a punching plate which is easy to manufacture has a large number of long holes so that it can be applied to a carrier having a small particle size.

[0008] That is, the bioimmobilized carrier separation screen according to the present invention has a structure in which the bioimmobilized carrier is suspended in the wastewater to be treated in the reaction tank to prevent the bioimmobilized carrier from flowing out of the reaction tank. In a sewage treatment apparatus provided with a biologically immobilized carrier separation screen at an outlet of a reaction vessel to separate a carrier from an effluent, the biologically immobilized carrier separation screen comprises a punching plate having a number of long holes. It is characterized by the following.

The material of the punching plate may be a material having a large strength such as a steel plate, and the elongated hole formed in the punching plate may be an oval, a rectangle, or the like. By preventing the outflow of the bioimmobilized carrier, the amount of the bioimmobilized carrier in the reaction vessel can be maintained at a predetermined value.

[0010] Further, in order to prevent or reduce the clogging of the screen by foreign substances such as the biologically immobilized carrier and the residue, a washing mechanism with air, for example, an air diffuser, is provided downstream of the biologically immobilized carrier separation screen. Is preferred.
In particular, by installing an air washing mechanism at the downstream lower end of the biologically immobilized carrier separation screen along the same screen, a reliable upward flow can be generated near the biologically immobilized carrier separation screen. Can be effectively prevented or reduced.

The apparatus for replacing a biologically immobilized carrier separation screen according to the present invention prevents a biologically immobilized carrier floating in sewage to be treated in a reaction tank from flowing out of the tank and removes the biologically immobilized carrier from the effluent. For separation, in a sewage treatment apparatus provided with a biological immobilization carrier separation screen at the outlet of the reaction tank, at least on both sides of the outer surface of the outlet, a pair of holding frames having a U-shaped cross section are provided. A single biological immobilization carrier separation screen is mounted across these holding frames, and when the slot of the screen is closed, another unused biological immobilization is carried out in parallel with the closed screen. The carrier separation screen is inserted across a pair of holding frames, and the closing screen is withdrawn from the holding frames.

According to this device, the blocking screen can be replaced with an unused one without lowering the water level of the reaction tank and without stopping the inflow of the wastewater to be treated into the tank. Impurities can be removed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described based on the illustrated embodiment.

FIG. 1 is a schematic diagram of a sewage treatment apparatus provided with a biologically immobilized carrier separation screen according to the present invention.

The wastewater to be treated or the liquid after the pretreatment is introduced into the reaction tank (1), and the biologically immobilized carrier (2) is contained in the liquid in the tank.
Is floating. The microorganisms adhering to the biological immobilization carrier (2) in the reaction tank (1) and the microorganisms floating in the tank liquid purify the sewage by being oxidized or reduced to purify the wastewater. Be transported.

An outlet (4) is provided above the outlet side of the reactor (1), and a laterally projecting outlet chamber (5) is provided outside the outlet (4) in communication with the reactor (1). Installed in the outflow chamber (5)
(6) is connected. Inside the outlet chamber (5), a biological immobilization carrier separation screen (3) is vertically arranged along the outlet (4), and is attached to the outer surface of the outlet (4).

As shown in FIG. 2 (a), the bioimmobilization carrier separation screen (3) is composed of a punching plate formed by drilling a number of elongated holes (9) extending vertically in a steel plate. The shape of the long hole (9) is an oval shape as shown in FIG. 2 (b), the width (W) of the hole is smaller than the particle size of the biological immobilization carrier (2), and the length of the hole (9) L) is 20 to 100 mm. By setting the length (L) to 20 mm or more, even if the sewage flowing into the reaction tank (1) is sufficiently dust-removed (the mesh width of the dust-removing mesh is 1 mm) before flowing, the remaining fibrous material can be removed from the long holes (9). ).

The bioimmobilized carrier separation screen (3) is usually installed vertically along the outlet (4) as described above, but can be inclined toward the reaction tank (1) or the outflow chamber (5). You may do it. In this case, the lower end of the biological immobilization carrier separation screen (3) is tiltably attached to the bottom wall of the outflow chamber (5). The bioimmobilized carrier separation screen (3) is shown in Fig. 1.
As shown by the broken line inside, the lower end mounting part (7) can be inclined to the inside of the reaction tank (1) via the outlet (4) with the fulcrum as a fulcrum,
It can also be inclined in the opposite direction to the inside of the outflow chamber (5).

As shown in FIG. 1, the biologically immobilized carrier separation screen (3) is used to prevent or reduce the blocking of the screen by the biologically immobilized carrier and impurities such as residue. An air diffuser (8) consisting of a tube having a number of air diffusers is provided along the lower downstream end of the separation screen (3), that is, at the bottom of the outflow chamber (5). By installing this air diffuser (8), it is possible to generate a reliable upward flow in the vicinity of the biologically immobilized carrier separation screen (3), and to diffuse carrier particles and residue coming close to the screen. By pushing up in the upward flow, they can be prevented from firmly adhering to the screen (3), and blockage of the screen (3) can be effectively prevented or reduced.

In the unlikely event that the biologically immobilized carrier separation screen (3)
When the long hole (9) is firmly blocked by carrier particles or residue, etc., which cannot be eliminated even by the air diffuser (8), it is necessary to directly remove the strong deposits on the screen. That is, as shown in FIG. 3, a pair of holding frames (10) having a U-shaped cross section are attached to both sides of the outer surface of the outlet (4) so as to face each other. The width of the U-shaped holding frame (10) is
(3) is set to be able to hold two sheets. One biological immobilization carrier separation screen (3) is held over these holding frames (10) to perform sewage treatment. If the slot (9) is firmly closed as described above, another unused biologically immobilized carrier separation screen (3 ′) is placed in parallel with the blocking screen (3) by a pair of holding frames (3). 10), the blocking screen (3) is pulled out from the pair of holding frames (10), and foreign substances adhering thereto are removed. According to this method, the blocking screen (3) can be replaced with an unused one without lowering the water level of the reaction tank (1) and without stopping the inflow of wastewater to be treated into the tank.

When the present invention is applied to a large-scale sewage treatment apparatus, a large number of the systems shown in FIG. 3 can be used in parallel.

Evaluation Test The biological immobilization carrier separation screen composed of a punching plate having a large number of long holes (9) and the biological immobilization composed of a punching plate having a large number of circular holes prepared for comparison according to the examples. Sewage treatment was performed using the carrier separation screen and the biologically immobilized carrier separation screen composed of a wire mesh, respectively, and the operation states of the devices were compared. Table 1 shows the results.

[0023]

[Table 1]

It is clear from Table 1 that the biologically immobilized carrier separation screen of the example is superior to the others in that the screen is not clogged.

[0025]

According to the present invention, the screen can be applied to the use of a carrier having a small particle size, and the upward flow of the diffused air along the screen is reliably generated to prevent the screen from being clogged. In addition, the replacement of the closing screen can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a sewage treatment apparatus provided with a biologically immobilized carrier separation screen according to the present invention.

FIG. 2 (a) is an enlarged front view showing a biologically immobilized carrier separation screen according to the present invention. FIG. 2 (b) is a partially enlarged front view showing an elongated hole of the biological immobilized carrier separation screen according to the present invention.

FIG. 3 is an enlarged horizontal sectional view showing a device for replacing a biologically immobilized carrier separation screen according to the present invention.

[Explanation of symbols]

 (1): Reaction tank (2): Bioimmobilized carrier (3): Bioimmobilized carrier separation screen (4): Outlet (5): Outflow chamber (6): Outflow pipe (7): Lower end mounting part ( 8): Air diffuser (9): Slot (10): U-shaped holding frame

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuhiro Akamine 2-9-1, Noribori, Nishi-ku, Osaka City F-term (reference) in Ataka Industry Co., Ltd. 4D003 AA12 BA02 CA02 DA07 DA30

Claims (3)

[Claims] 1. An organism-immobilized carrier floating in sewage to be treated in a reaction tank is prevented from flowing out of the tank and the carrier is separated from an effluent. In the sewage treatment apparatus provided with the immobilized carrier separation screen, the biologically immobilized carrier separation screen is characterized by comprising a punching plate having a large number of long holes, the biologically immobilized carrier separation screen in the sewage treatment apparatus. . Further, in order to prevent or reduce clogging of the screen by foreign substances such as the biologically immobilized carrier and residue, a washing mechanism with air is provided downstream of the biologically immobilized carrier separation screen. The biological immobilized carrier separation screen according to claim 1. 3. An organism-immobilized carrier floating in sewage to be treated in a reaction tank is prevented from flowing out of the tank and the carrier is separated from an effluent. In the sewage treatment apparatus provided with the immobilized carrier separation screen, at least on both sides of the outer surface of the outlet, a pair of holding frames having a U-shaped section in cross section are attached to face each other,
One biological immobilization carrier separation screen is held over these holding frames, and when the long hole of the screen is closed, another unused biological immobilization carrier separation screen is placed in parallel with the closed screen. An apparatus for replacing a biologically immobilized carrier separation screen in a sewage treatment apparatus, wherein the screen is inserted over a holding frame and the closing screen is withdrawn from the holding frame.