JP3122010B2 - Microorganism-immobilized carrier floating sewage treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment apparatus,
In particular, the present invention relates to a sewage treatment apparatus for biologically treating organic sewage such as sewage, human waste, and industrial wastewater using a floating organism-immobilized carrier.

[0002]

2. Description of the Related Art In recent years, the activated sludge method, biofilm method, immobilized microbial method and the like have been remarkably widespread. The development of equipment is urgent. Among them, a sewage treatment apparatus using a microorganism-immobilized carrier has attracted attention, particularly in conjunction with the improvement of the performance of the carrier material. Heretofore, the present inventors have developed a biological sewage treatment apparatus using an immobilized carrier, but encountered the following technical problems in the development process. That is, as a result of the immobilized carrier flowing down in the biological reaction tank together with the water to be treated, the carrier concentration at the end increases, and scum adheres to the screen-like carrier separation part in the outflow part, and the water level in the biological reaction tank increases. And it has become necessary to intermittently clean the carrier separation section using industrial water or the like. This causes a problem in that the treatment performance is reduced due to the inability to uniformly hold the carrier, and the treated water drainage is blocked.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, ensures that the carrier is held in the tank, and that the water level in the reaction tank due to scum adhering to a screen or the like at the treated water outlet. It is an object of the present invention to provide a sewage treatment apparatus provided with a water collecting device capable of preventing the rise and reducing the trouble of removing the scum.

[0004]

According to the present invention, there is provided an underwater aerator for aeration and stirring for holding a carrier having microorganisms immobilized thereon in a floating state .
A sewage treatment apparatus having a treatment tank having a rectangular shape in a plan view , provided with pipes having water collection holes at regular intervals inside covered with a cylindrical screen for preventing the carrier from flowing out. A microorganism-immobilized carrier-floating type sewage treatment apparatus, wherein a plurality of apparatuses are arranged in parallel so as to project substantially horizontally from an outlet portion in the treatment tank toward a center part. In the above, the surface of the cylindrical screen of the water collecting device is preferably coated with a substance having a sterilizing and algicidal effect. That is, when the material of the cylindrical screen is coated with copper plating or an optical semiconductor (Ti compound such as titanium oxide) on SS or SUS, a sterilizing effect can be expected, and scum attached to the screen can be reduced as much as possible. In addition, when they adhere, they have an advantage that they can be easily peeled off, which is preferable.

Conventionally, the water collecting device was installed at the outlet of the treatment tank, so that the scum adhered to the water collecting device was directly affected by the water flow. However, in the present invention, the water collecting device is directed from the outlet toward the center. Since a plurality of water collecting devices are installed, it is difficult for the scum to concentrate on the carrier separating portion due to the water flow . Also, even intracisternal end of the pipe is closed, there may be holes. In addition, the arrangement of the water collecting devices at the time of multiple installation may be parallel to the flow in the tank,
They may be arranged transversely, and may be appropriately selected depending on the shape of the tank, the amount of inflow water, and the like. In addition, the above-described device is an anoxic process,
The aerobic process and the sedimentation process are connected sequentially, the aerobic process effluent is circulated to the anoxic process, and the settling sludge of the sedimentation process is returned to the anoxic process. The method is preferably applied to an aerobic step in a denitrification / dephosphorization activated sludge method in which an anaerobic step is provided and the settled sludge in the settling step is returned to the anaerobic step. Of course, the present apparatus can be applied to the anaerobic process and the oxygen-free process.

[0006] In addition, even in the case where the existing capacity is to be improved by using a carrier in an existing aeration tank, the cylindrical screen of the present apparatus can be easily installed at the outlet or the inlet and the outlet of the aeration tank. The effect as the device of the present invention can be achieved. As the immobilization carrier used in the present invention, sand, activated carbon, polyurethane foam, polyvinyl alcohol, polypropylene, polyethylene, polyethylene glycol, a fluid carrier such as cellulose, the present invention,
The application is not limited to these carriers. As a method for immobilizing microorganisms on a carrier, an adhesion immobilization method is generally used, but an inclusive immobilization method is also applicable.

[0007]

According to the present invention, since the water collecting device uses a pipe covered with a cylindrical screen, the outflow point is dispersed, so that uneven distribution of the carrier due to the flow in the tank does not easily occur and the uniformity of the carrier can be easily achieved. Dispersion can be maintained. In addition, concentration of scum hardly occurs and blockage of the outflow portion hardly occurs. Further, by adding a bactericidal or algicidal effect, blockage due to generation of attached microorganisms can be avoided. Further, in the case of the aerobic tank, the air bubbles directly rise on the lower surface of the screen part for separating the carrier. That is, the amount of bubbles received per screen area is larger than when the screen is provided only on the outlet side, and a higher air cleaning effect can be expected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to the drawings, but the present invention is not limited thereto. Example 1 FIG. 1 shows a plan view in which a sewage treatment apparatus of the present invention is used for an aerobic treatment tank for sewage, and FIG. 2 is a longitudinal sectional view of FIG. FIG.
And in FIG. 2, 1a and 1b are aerobic tanks, 2 is a microorganism-immobilized carrier, 3 is a submersible aerator, 4 is a blower, 5 is an air pipe, 6 is a water collecting device, 7 is an inlet pipe of raw water, and 8 is a treatment. A water outflow pipe, 10 is a circulating fluid pump, 11 is a circulating fluid pipe, 1
Reference numeral 2 denotes a partition wall.

In such an apparatus, the raw water is supplied to the inflow pipe 7.
The carrier 2 on which the microorganisms are immobilized flows uniformly by aeration and stirring in the underwater aerator 3 to biologically treat the raw water. Raw water treated in the aerobic tank 1a is collected by the water collecting device 6 and introduced into the aerobic tank 1b through a partition wall. The aerobic tank 1b is also treated with the microorganism-immobilized carrier that is uniformly fluidized and dispersed by aeration and stirring by the underwater aerator 3. The treated water is collected by the water collecting device 6 and discharged through the outflow pipe 8. In this example, since four water collecting devices are installed in each of the processing tanks 1a and 1b, the water is dispersed and collected by these, so that the accumulation of the carriers does not occur.

Next, details of the water collecting device 6 will be described. FIG. 3 shows an overall configuration diagram of the water collecting device 6, and FIG.
FIG. 3 and 4, reference numeral 13 denotes a cylindrical screen, and reference numeral 14 denotes a pipe having a water collecting hole 15. The water collecting device 6 is installed below the water surface, and the empty washing tube 16 for removing biological scum may be installed below the water surface as needed. The outer cylindrical screen
The mesh width is preferably about 1 to 5 mm smaller than the carrier diameter, and the material is SS or SUS plated with copper. The inner pipe is made of SUS and has a hole (which may be an elongated hole, that is, a slit) of the water collecting hole 15 all around. With such a configuration, in the water collecting device, only the treated water is collected from the entire surface of the pipe, and the water pressure is not locally applied and the carrier is not accumulated. In FIGS. 1 and 2, 1a
Is used as a denitrification tank of an anaerobic tank, 1b is used as a nitrification tank of an aerobic tank, and the treated water of the nitrification tank is circulated to the denitrification tank using the circulating liquid pipe 11 by the pump 10 to form a circulating nitrification denitrification method.

[0011]

According to the present invention, in the collection of treated water, uneven distribution of the carrier is less likely to occur, the screen is less likely to be clogged due to scum concentration, and a higher emptying effect is obtained. It is not necessary to equip the aerobic tank and the anaerobic tank with a screen cleaning device, so that maintenance work can be omitted and the initial cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sewage treatment apparatus of the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is an overall configuration diagram of a water collecting device used in the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

[Explanation of symbols]

1a, 1b: aerobic tank, 2: carrier, 3: underwater aerator,
4: blower, 5: air pipe, 6: water collecting device, 7: inflow pipe,
8: Outflow pipe, 9: Air flow meter, 10: Circulating fluid pump, 1
1: circulating liquid pipe, 12: partition wall, 13: cylindrical screen, 14: pipe, 15: water collecting hole, 16: empty washing pipe, 1
7: Water surface

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-248499 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C02F 3/08 ZAB

Claims (2)

(57) [Claims] 1. A submersible aerator for aeration and stirring for holding a carrier in which microorganisms are immobilized in a floating state.
A sewage treatment apparatus having a treatment tank having a rectangular shape in a plan view, wherein a pipe having water collection holes at regular intervals is disposed inside the cylindrical sewage treatment vessel, which is covered with a cylindrical screen for preventing the carrier from flowing out. A plurality of cells are arranged in parallel with each other so as to protrude substantially horizontally from an outlet portion in the treatment tank toward a central portion thereof. 2. The microorganism-immobilized carrier floating type sewage treatment according to claim 1, wherein the cylindrical screen of the water collecting device is coated with a substance having a sterilizing and algicidal effect on the surface of the screen member. apparatus.