JPS6012193A - Fluidized bed type biological treatment apparatus - Google Patents

Abstract

PURPOSE:To efficiently remove an organism adhered to and penetrated into a sponge carrier, by intermittently taking out a part of the sponge carrier having the organism adhered thereto from a treating tank to bring the same into contact with an acidic liquid. CONSTITUTION:A porous sponge like substance 2 is introduced into the treating tank 1 of a fluidized bed type biological treatment apparatus as a microorganism carrier and fluidized by diffusing air from an air diffusing apparatus 3 provided to the bottom of the tank 1 to treat sewage supplied into and stayed in the treating tank 1 with the organism adhered to the sponge like substance 2. A discharge means 4 comprising a drum for discharging the sponge like substance 2 while rotated by a horizontal drive shaft is provided to the treating tank 1 while the discharged sponge substance 2 is taken out from a flooding port 1' and drained by a screen apparatus 5 to be fallen in an immersion tank 7 into which an acidic liquid is introduced. The sponge like substance 2 is stirred by rotating a rake 7' and successively discharged out of the tank 7 to be squeezed through a squeezing apparatus 8. The squeezed sponge like substance 2, from which the microorganism is removed, is neutralized in a neutralization tank 10 before returned to the treating tank 1 through a conduit 12.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a porous spongy material (i.e.
Just a sponge and also a mandrel. ) as a carrier for microorganisms,
The present invention relates to a fluidized bed biological treatment device that fluidizes wastewater in a treatment tank and removes BOD components and harmful substances in the wastewater supplied to the tank by biologically oxidizing, reducing, etc. using microorganisms held by carriers.

In this way, aerobic or anaerobic fluidized bed treatment equipment using microorganisms has a high processing capacity per unit capacity of the treatment tank, and not only does it not cause bulking problems, but it is also possible to omit the settling tank. On the other hand, the organisms attached to the carrier multiply as the operating time passes, and when it reaches the top of the lid, it detaches from the carrier, and the detached organisms become microscopic and mix into the treated water, causing Deteriorate water quality. Therefore, if enough force is applied to the amount of organisms attached to the carrier, it is necessary to forcibly separate them from the raw *'t- carrier and discharge them as excess sludge to the outside of the system.

Conventionally, when a sponge is used as a carrier, detachment of organisms is carried out by taking several carriers out of a tank, squeezing them with a roll, etc., and squeezing them. However, although the sludge adhering to the surface of the carrier can be removed by squeezing, the sludge inside can hardly be removed, and when the sponge is squeezed and returned to the tank for circulation, the inside of the sponge eventually becomes clogged, resulting in this condition. When this happens, only the sludge on the surface of the sponge is treated for BOD components and harmful substances, so the sludge concentration in the treatment tank decreases, and the treatment capacity of the f'LK-i device also decreases, and the quality of the treated water decreases. Getting worse.

The inventors of the present invention have tried various sounds of detachment of living things from sponges, and have found that sponges with living things attached to them? I: It was discovered that when brought into contact with an acidic liquid, living organisms, both those attached to the surface in a film form and those that have penetrated into the sponge, change in quality and easily separate from the sponge, leading to the unexploded 8A'9T. It's coming out,
A means for removing and discharging a portion of the sponge carriers with living organisms attached thereto from a treatment tank, an acid treatment device for contacting the vomited sponge carriers with an acidic liquid, a means for dehydrating the acid-treated sponge carriers, and a dehydrated sponge carrier. The processing tank is characterized by a pipe that is provided with return means for returning the water to the processing tank. The invention will now be described with reference to illustrated embodiments.

l is a treatment tank to which wastewater is supplied, and the specific gravity in the tank is -/,
In the vicinity of θ, the porous pore diameter is about 0.1''39, the volume is about t-1000a11, and an infinite number of sponge carriers that can withstand compression, such as spherical or angular shapes, are inserted. The sponge carrier is fluidized in the tank by aeration from the entire surface of the bottom of the tank with the aeration device 3, and the wastewater supplied into the tank is allowed to linger for, for example, 2 hours, during which time BOD components and harmful components in the wastewater are removed. The substances are treated with organisms attached to the sponge carrier and discharged from the bath outlet l' as treated water of good quality.

Near the liquid level of the treatment tank, there is a rake (
A discharging means q such as a drum (indicated by a broken line) or a drum (indicated by a solid line) with a pin protruding from the outer periphery and rotated by a horizontal drive shaft is provided, and some of the sponge carriers in the bath are taken out from the bath outlet l'. As the discharge means, a rake is suitable when the planar shape of the processing tank is cylindrical, and the rotating drum is suitable for any of cylindrical, square, and polygonal shapes.

In this way, the treated water and the sponge carrier are discharged from the outlet /', so the sponge carrier is passed through and separated by the sieving device S, and the treated water is sent to the water receiver under the sieving device. is collected and discharged into B, and the sponge carrier is filled with acidic liquid f'L72.
．． It is dropped into the dipping tank 7, and the acidic liquid is impregnated into the sponge carrier.・The acidic liquid preferably has a pH of 3 or less, such as ordinary hydrochloric acid,
An aqueous solution of about 5 tir of sulfuric acid may be used, or a p'6 salt,
Things that are acidic in themselves, such as AL salts, can be used in aqueous solutions.
However, a mixed solution of these is also better. It is most preferable to include the metal salts mentioned above, since the metal salts function as a collecting agent in the neutralization step described later. The immersion time is approximately 13 to 9 minutes at 1 and 2, but if the acid solution is heated to 20 to 20 minutes, the immersion time is preferably shortened to 5 to 10 minutes, but this is not necessarily necessary. Hanahani. - When the sponge carrier is impregnated with an acidic solution in this soaking tank, not only the membrane-like organisms on the surface of the carrier but also the organisms that have penetrated into the porous interior are denatured by the acid and become easily separated from the sponge. . □Therefore, the rake 71y rotates near the liquid surface of the dipping tank to stir the carrier, and at the same time, the carrier is successively discharged from the tank and passed through the squeezing device g to squeeze the sponge carrier.

The squeezing device g may be a pair of upper and lower rolls, or may be a simple screw press, a P/l/) press, or any other device that can squeeze the sponge carrier and squeeze out the moisture inside.

As a result, the organisms on the surface of the carrier that have changed in quality are peeled off, and
The living organisms inside the carrier also come out of the carrier together with the squeezed water, and the sponge carrier is also squeezed out with water. - The water squeezed out from the carrier is received in a water receiver 9 under the squeezing device, and introduced into the carrier into a neutralization device 10, where the acidic liquid contained in the carrier is neutralized with an alkaline solution.

In this embodiment, the neutralization device 10 is a sieve 10 through which the carrier does not pass through.
a, and a shower pipe 106 that sprays an alkaline solution onto the sieve IOa, so that the Tasponsi carrier is neutralized by being sprayed with the alkaline solution as it passes through the squeezing device If and completely rolls over the sieve 10α. ing. and neutralized nfc
The carrier is &! It falls into the water 41 // from the inclined lower end of /θα, for example, one end plunges below the water surface of the water tank // from above, and the other end is connected to the treatment tank by the air lift pipe 7.2 located above the treatment tank l. It will be sent back inside. Note that lj indicates an air supply pipe that blows air into the interior of one end of the air lift pipe that protrudes into the water tank from above. The sponge carrier may be returned from the water tank // to the treatment m/ by scooping it out from the water tank and transferring it instead of using an air lift.

The sponge carrier is separated from the acidic liquid in the immersion tank 7.
yt organisms are mixed in. In addition, during the water receiving vessel that receives the acidic liquid squeezed out from the carrier by the squeezing device S, NFC is released from the carrier.
Contains living organisms. For this reason, the acidic liquid in the immersion tank and the water receiver are used to extract the acidic liquid in the tank, and the alkaline solution is also extracted from the water receiver IOC which receives the alkaline solution sprayed onto the carrier by the neutralization device 10. The liquid is put into the mixing tank/JVc and neutralized to cause flocculation, which causes the organisms to settle as sludge, and the settled sludge is discharged from the bottom of the mixing tank.
The overlying liquid is returned to the supply pipe /4I for supplying wastewater to the treatment tank 1 by the pump 1S1 return pipe 16, mixed with the wastewater, and supplied to the treatment tank.

When the acidic liquid inside contains P'e salt and AJ salt, and f'L
Since these act as flocculants, the flocculating effect is good.

Of course, a flocculant such as polymer flocculant 1 or FeC 6H20 may be added to the mixing tank if necessary.

As described above, according to the illustrated flow sheet, the sponge carrier impregnated with the acidic liquid is squeezed using a squeezing device, and then the neutralization device VI
Although it has been explained that the sponge carrier impregnated with the hostile liquid is neutralized with an alkaline solution in Lto, it is not limited to this, but the sponge carrier impregnated with the hostile liquid may be neutralized with an alkaline solution in a neutralization device, and then squeezed with a compression device. . In this case, since the neutralized sponge carrier is squeezed, there is an advantage that the material of the squeezing device does not need to be made acid-resistant.

In addition, when squeezing the carrier impregnated with acidic liquid, squeeze out 7
Another advantage is that the amount of acidic liquid used can be reduced by returning the liquid to the dipping tank 7 for circulation. Of course, in this case, it is only necessary to extract the acidic liquid from the dipping tank into the mixing tank/JK, mix it with the alkaline solution from the neutralizer, and neutralize it.

Next, an experimental example of the present invention will be shown.

Capacity Jj1 A polyethylene sponge carrier (with a specific gravity of approximately 0.1 to 0, the diameter of the pore opening is approximately 0.1 to 0, and the shape is a regular hexahedron of approximately /-) is placed in a treatment tank that diffuses air from the entire bottom surface. 2s% of the capacity of f
L, mainly glucose while diffused; bBOD!
Sewage of r00WVJ- was allowed to flow in for a residence time of φ hours.

A small amount of seed sludge was added during the first week of operation, but
After that, the addition of sludge was stopped and the treatment was carried out using only the organisms attached to the surface and inside of the sponge carrier.

The microorganism QylJ belonging to the organism T-component was dominated by mold, and normal activated sludge (Zooglaia type) and protozoa were also deformed.

Sponge carrier' is sieved with 9HT! As a result of filtration through a Damesh sieve with a size of 4', the water quality of the p liquid was found to be below BB10''fA and below BOD s %/J.

Sponge carrier with attached organisms' (1-F$CJ, 6H
After immersing the carrier in hydrochloric acid (5%) in which 70% of 20 was dissolved, the attached organisms were easily peeled off from the carrier.

When the hydrochloric acid solution was neutralized, the exfoliated sludge was contained in the iron hydroxide sludge and showed good flocculation.

The amount of surplus organisms generated varies depending on the quality and concentration of sewage, the load on the treatment tank, etc., and in some cases, there may be no surplus. Therefore, in carrying out the process, it is preferable to consider the amount of organisms generated on the sponge carrier, and adjust the Mt of the sponge carrier taken out from the treatment tank and immersed in the acid solution accordingly.

[Brief explanation of drawings]

The drawing is a flow sheet of an embodiment of the present invention, in which l is a treatment tank, - is a sponge carrier, 3 is an aeration device, 7 is an immersion tank containing an acidic liquid illustrated as a gorge treatment device, and 10 Reference numeral 12 indicates a neutralization device, and 12 indicates an air lift pipe as an example of a return means.

Claims (1)

[Claims] A porous spongy material is placed in the treatment tank as a microbial carrier.
In a fluidized bed biological treatment equipment, wastewater is fluidized by air diffused from the bottom of the tank, and the sewage that stagnates in the treatment tank is treated with organisms attached to the carrier. In addition to providing a discharge means for discharging, an acid treatment device for bringing the discharged A* carrier into contact with an acidic solution, a dehydration means for dehydrating the carrier treated with the acid treatment device, and a return transport for returning the dehydrated carrier to the treatment tank. A fluidized bed biological treatment device characterized in that a means is attached to a treatment tank.