JPH11267678A - Carrier added biologically treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a microorganism holding amount of a carrier adding biologically treating device and to separate the microorganism carrier from a treated water without causing a clogging at a carrier separating means. SOLUTION: This treating device is provided with a reaction tank 10 in which a microorganism carrier 12 is packed and also to which a raw water supply means 11 is connected, a cylindrical carrier separating means 14 immersing in the tank while positioning its upper end on a liq. surface of the reaction tank 10 and provided with a waste water discharge means 16 discharging a treated water flowed inside to the outside of the tank 10, a carrier removing means 19 revoluting around an outer periphery surface of the carrier separating means and having a gap between the carrier separating means 14 and the means 19 kept smaller than the particle size of the microorganism carrier and an agitating means 13 agitating the liq. in the reaction tank and the microorganism carrier at an under side of the carrier separating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier-added biological treatment apparatus for performing biological treatment such as nitrification, denitrification, and fermentation by using a microorganism carrier filled in a reaction vessel.

[0002]

2. Description of the Related Art In biological treatment, since microorganisms are treated in a reaction vessel, the load can be increased by increasing the concentration of microorganisms retained in the vessel. As a method of increasing the amount of microorganisms held in the reaction tank, there is a method of adding a carrier that supports microorganisms to the reaction tank, but there is a problem that the carrier separation means for separating treated water from the carrier is easily blocked by the carrier. .

[0003]

For example, in a method involving aeration, a gel carrier carrying microorganisms is added to a nitrification tank, and a wedge wire screen is used as a carrier separation means, and the wedge wire screen surface is aerated. This prevents the gel-like carrier from blocking the wedge wire screen. However, when the flow rate of the treated water passing through the wedge wire screen increases, the wedge wire screen is blocked. or,
In the method that does not involve aeration such as denitrification, because aeration cannot be used, a carrier separation cylinder made of a cylindrical wedge wire having a bottom is immersed in a reaction tank, and the upper end of the separation cylinder is projected above the water surface. This carrier separation tube is filled with a gel-like carrier carrying microorganisms, and the carrier removal wing is swirled along the inner periphery of the separation tube, and the gel-like carrier tries to close the gap between the wedge wires from the inside. Although the prevention is carried out by scraping, when the gel-like carrier has elasticity, blockage tends to occur. As shown in FIG. 3, the screen surface of the wedge wire blocks the traveling direction of the gel-like carrier due to the rotation of the carrier removing blade, so that the gel-like carrier is pressed against the screen surface, and a part of the carrier is elastically deformed. Then, it is pushed into the gap between the wedge wires and becomes clogged.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed with the object of providing a carrier-added biological treatment apparatus having a mechanism capable of increasing the amount of microorganisms held in a reaction tank and preventing blockage of the carrier. In the reaction vessel connected to the raw water supply means while filling the microbial carrier, and provided with the upper end positioned immersed in the vessel with the upper end positioned on the liquid surface of the reaction vessel, the treated water flowing into the inside A cylindrical carrier separation means provided with a drainage means for discharging outside of the reaction tank, and a carrier removal means in which the outer peripheral surface of the carrier separation means is swirled and a gap between the carrier separation means and the particle diameter of the microorganism carrier is made smaller. And a stirring means for stirring the liquid in the reaction tank and the microorganism carrier under the carrier separating means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 10 designates a feed pipe 1 at the bottom of a tank.
1. The reaction tank supplied in 1 and contains a gel-like microorganism carrier 1 in the tank.
2 is added and stirred by the stirring blade 13. The gel-like microorganism carrier 12 is made of polyacrylamide, carrageenan, agar, polyvinyl alcohol, sodium alginate,
It is mainly composed of polyethylene glycol or the like, and has a diameter of 0.1 to 10.0 mm, preferably 1.0 to 5.0 m.
m, specific gravity 0.5-3.0 g / cm ³ , preferably 0.9
It is preferable that inorganic particles having a particle size of 5 to 40 [mu] m, such as zeolite, having fine irregularities on the surface of about 1.1 g / cm < ³ > and adhering about 1 to 10% of the weight of the carrier when dried. The amount of addition is 0.1 to 80%, preferably 10 to 50% by apparent volume of the reaction tank. The microorganisms carried by the carrier are appropriately determined depending on the purpose of biological treatment, such as general heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria, methane bacteria, yeast, or a mixed system thereof. The rotation speed of the stirring blade 13 is 3
It is about RPM.

[0006] Above the inside of the reaction vessel, a bottomed carrier separation cylinder 1 having a cylindrical surface formed by a wedge wire or a punched metal screen having a void smaller than the particle size of the carrier.
4 is supported by, for example, a radial support member 15 so that its upper end projects upward from the water surface of the reaction tank, and is immersed in the tank. Then, a drain pipe 16 of the treated water to the outside of the reaction tank is connected to the bottom of the carrier separation tube 14. Carrier separation tube 14
Has a hollow portion 17 at the center, a rotary shaft 18 rotated by a motor or the like provided along the center of the reaction tank is penetrated and supported in the hollow portion, and the above-described stirring blade 13 is provided at the lower end of the rotary shaft. Installed.

[0007] An inverted U-shaped carrier separation wing 19 is fixed to the rotating shaft 18 so as to straddle the carrier separation tube 14 in the diameter direction and rotate around the outer peripheral surface of the separation tube. A rubber plate may be attached to the surface 19 ′ of the carrier separation blade 19 facing the outer periphery of the carrier separation tube 14, and may be elastically contacted and stroked when turning the outer periphery of the separation tube. However, when a gap is maintained between the carrier separation tube and the outer peripheral surface, the gap is made smaller than the particle size of the microorganism carrier.

[0008] The raw water supplied from the supply pipe 11 to the bottom of the reaction tank comes into contact with the gel-like microbial carrier 12 added to the tank while being stirred by the stirring blades 13, and the biodegradable substances in the raw water are decomposed by microorganisms. Then, the microorganism-like microorganism carrier flows into the carrier separation tube 14 while being separated by a wedge wire or punching metal on the circumferential surface, and is taken out of the reaction tank from the drain pipe 16.

Due to the flow of the biologically treated water flowing out of the drain pipe 16 through the carrier separation tube 14, the gel-like microbial carriers collect outside the wedge wire screen or the perforated metal screen surface of the carrier separation tube 14, and the screen surface. To prevent the biologically treated water from flowing into the carrier separation tube 14. However, on the outer periphery of the carrier separation cylinder, an inverted U-shaped carrier removal blade 19 that rotates along the screen surface is provided across the cylinder 14 in the diameter direction,
The surface 19 'of the removing blade 19 facing the outer periphery of the carrier separation cylinder.
The gaps are smaller than the particles of the gel-like microbial carrier, whether stroking the periphery or apart. As a result, the traveling direction of the gel-like microorganism carrier 12 due to the rotation of the carrier removing blade 19 is widely vacant as shown in FIG. 1B, so that the carrier is not pressed against the screen surface of the carrier separating cylinder. Therefore, the carrier is elastically deformed and clogs the screen surface,
It does not obstruct the flow of the treated water into the carrier separation cylinder.

Then, as in this embodiment, the stirring blade 13
By attaching the carrier removing blade 19 to the common rotating shaft 18 and driving the same to rotate, the structure is simplified and the power cost can be reduced.

A polyethylene glycol-based gel having a diameter of 4 mm and carrying microorganisms in the reaction tank 10 has an apparent volume of 5 mm.
0% was added, and after passing water for 72 hours, the closed state of the wedge wire screen surface on the outer periphery of the carrier separation cylinder was examined. still,
The aperture of the screen surface of the wedge wire is 1.5m
m, and the aperture ratio was 50%. The denitrification load of the apparatus was 2.0 kg-N / m ³ · day, the HRT was 1.5 hours, the screen aperture was 2.0 mm / 2.0 mm (screen opening width / wedge wire width), and the screen passing flow rate 40
m / hr.

As shown in FIG. 3, when the carrier removing blade is turned along the inner periphery of the carrier separating cylinder, the screen closing rate is 5.
In contrast to 8%, when the carrier removing blade is turned along the outer circumference of the carrier separation cylinder as shown in FIG. 1 (B), the screen blocking rate is 0.1%, and almost no blocking occurs. Was.

[0013]

As is clear from the above, in the present invention, the microorganisms are added to the reaction tank by the carrier, so that the microorganism holding amount is increased, the processing with a high load can be performed stably, and the reaction tank is downsized and installed. The area can be reduced. Further, the carrier separation means for separating the microorganism carrier from the treated water does not become blocked.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of one embodiment of the device of the present invention, FIG.
FIG. 4 is an explanatory diagram of a state of separation of a carrier from a carrier separating means.

FIG. 2 is an enlarged perspective view of a main part of the embodiment of FIG. 1;

FIG. 3 is an explanatory view of a state of separating a carrier from a carrier separating means of a conventional apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reaction tank 11 Raw water supply pipe (supply means) 12 Microorganism carrier 13 Stirring blade (stirring means) 14 Carrier separation tube (carrier separation means) 15 Support member 16 Drainage pipe of treated water (drainage means) 17 Hollow of carrier separation cylinder Part 18 Rotation axis 19 Carrier removal wing (carrier removal means)

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[Procedure amendment]

[Submission date] April 9, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (1)

[Claims] 1. A reaction tank filled with a microbial carrier and connected to a raw water supply means, and an upper end portion is provided by being immersed in the tank with the upper end positioned above the liquid surface of the reaction tank and flowing into the inside. Cylindrical carrier separation means provided with a drainage means for discharging the treated water out of the reaction tank, and turning the outer peripheral surface of the carrier separation means,
A carrier removing means provided with a carrier removing means in which a gap with the carrier separating means is smaller than the particle diameter of the microorganism carrier, and a stirring means for stirring the liquid in the reaction tank and the microorganism carrier under the carrier separating means. Biological treatment equipment.