JPH0214118B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel biological treatment device for organic wastewater that enables energy saving and space saving.

[Conventional technology]

Conventionally, as a biological treatment device for biologically treating wastewater, a biological film is attached to a solid surface like the sprinkler bed method, and raw water is poured onto it to treat the water in the raw water.
It is known to remove BOD components.

Biological treatment equipment for sewage using the activated sludge method requires a separate settling tank after the aeration tank, and since the sedimentation rate of the activated sludge flocs after aeration is low, the installation area of the settling tank is small. It had to be huge.

[Problem that the invention seeks to solve]

However, in the past, the vast space above the water surface of the sedimentation basin was left unused. Furthermore, the separation zone below the water surface of the settling basin is also used solely as a storage area for clear water. On the other hand, solubility
For organic wastewater containing BOD components, low BOD treated water cannot be obtained by simply performing sedimentation treatment or coagulation sedimentation treatment, so it is necessary to perform pretreatment using some kind of biological treatment before sedimentation treatment. It was a problem.

The present invention aims to perform rational biological treatment and sedimentation treatment of organic wastewater by effectively utilizing the space such as the upper part of the sedimentation tank, which was previously wasted, for the biological treatment process. The purpose is to provide a device that makes it possible.

[Means for solving problems]

In the present invention, a water bed section 3, an immersion bed section 6, and a sedimentation section 10 are formed in communication with each other in order from the top to the bottom in the tank body, and a raw water sprinkling section 4 is disposed above the water sprinkling bed section 3. , the immersion bed section 6 is constructed of a granular solid that floats on water with a specific gravity of 1.0 or less, an aeration device 7 is provided in or below the immersion bed, and a treated water outflow section is provided in the settling section 10. 1
6 is formed around the immersion bed section 6.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. In the tank body 1, a watering bed section 3, an immersion bed section 6, and a settling section 10 are connected in this order from the top to the bottom. It is formed. A raw water sprinkler section 4 is provided above the immersed floor 3, and an aeration device 7 is provided below the immersed floor 6. In the settling section 10, an overflow launder 14 is sectioned around the immersion bed section 6 via an overflow section 16 to serve as a treated water outflow section.

In this case, the water flowing out from the sprinkler bed 3 does not flow into the settling part 10, but directly flows downward into the immersion bed 6 provided below the overflow water surface 2 of the tank body 1. After that, the biologically treated water flowing out from the lower part of the immersion bed section 6 is separated by precipitation in the settling section 10 in the tank body 1, and is sent out of the system as treated water 14' from the overflow launder 14 via the overflow section 16. It is configured so that it flows out.

In the figure, 8 is a scraper, 9 is a drive shaft, and 11 is a mud removal pipe.

Thus, the organic wastewater 4' is sprayed from the water sprinkling part 44 to the water sprinkling part 3 provided at the upper part of the tank body 1,
Approximately 60% of the BOD in the wastewater 4' is removed as it flows down the material surface in the sprinkler bed in a film-like manner.
It flows out from the lower end of the sprinkler bed section 3 and flows into the settling section 10 via the immersion bed section 6. In the sedimentation section 10, the water that has flowed into the immersion bed section 6 is supplied with oxygen by air bubbles supplied from the aeration device 7, and residual BOD that was not removed at the sprinkler bed section 3 is highly removed. Ru. Further, in the sedimentation section 10, sedimentary SS (such as biofilm peeled off from the watering bed) is precipitated and deposited as sludge, which is removed from the sludge pipe 11.

The treated water 14' obtained in this way is transferred to the immersion bed section 6.
It flows out of the system from the upper part through the overflow part 16 and the overflow launder 14.

Since the immersion floor section 6 is located below the overflow water surface 2 at the upper part of the tank body 1, the tank body 1 is
The adverse effect of disturbing the water flow inside the tank body 1 and interfering with the settling of the SS is small, and by providing the air diffuser 7 in the immersion bed, the turbulence of the water flow inside the tank body 1 can be almost completely prevented.

Furthermore, the materials for the immersion bed section 6 include foamed polypropylene particles, perlite, and wood chips with a specific gravity of 1.0.
Since the following granular solids that float on water are used, the material is agitated by the upward movement of air bubbles supplied from the air diffuser 7, so the immersion bed 6 is not clogged, and the lower part A supporting bed is no longer required and stable processing can be continued.

The air diffused into the immersed bed section 6 is discharged from the immersed bed section, but by introducing the air into the sprinkler bed section 3 without directly discharging it outside the system, the air can be reliably aerobic. It can be effectively used to maintain a safe atmosphere.

〔Effect of the invention〕

In the present invention, the immersion bed section 6 is constructed using granular solids floating on water with a specific gravity of 1.0 or less, an aeration device 7 is provided in or below the immersion bed, and the pre-sedimentation section 10 is provided with treated water. By forming the outflow section 16 around the immersed bed section 6, the material is agitated by the upward movement of air bubbles supplied from the aeration device into the immersed bed section, thereby preventing clogging of the immersion bed section. In addition, stable treatment can be continued without the need for a lower support bed, and the immersion bed is placed over the entire upper part of the sedimentation tank, which improves the efficiency of space use. Conventionally unused space such as the upper part can be effectively used as a biological treatment section, and the entire device is made extremely compact.As a result of the structure in which the treated water from the sprinkler bed is further treated at the immersion bed section, Since the amount of air supplied to the submerged bed is small and the depth of the aeration water is shallow at 1 to 2 m, the blower power is low, and the power consumption for the submerged bed treatment is only for pumping up the raw water. The energy consumption (Kg removal BOD/KWH) is very low, and since the exhaust air from the immersion floor is introduced into the sprinkler bed, the oxygen supply to the sprinkler bed can be done by natural ventilation as in the conventional method. This eliminates the need to rely on anaerobic treatment, reliably prevents the spread bed from becoming anaerobic, and allows stable biological treatment to continue.

[Brief explanation of drawings]

The drawings are longitudinal sectional views showing embodiments of the present invention. 1... Tank body, 2... Overflow water surface, 3... Sprinkling bed section, 4... Sprinkling section, 4'... Waste water, 6... Immersed bed section, 7... Air diffuser, 10... Sedimentation Part, 11...
... Sludge removal pipe, 14 ... Overflow launder, 14' ... Treated water, 16 ... Overflow section.

Claims (1)

[Claims] 1 A water sprinkling bed section 3, an immersion bed section 6, and a sedimentation section 10 are formed in communication with each other from top to bottom in the tank body, and a raw water sprinkling section 4 is provided above the water sprinkling bed section 3.
At the same time, the immersion bed section 6 has a specific gravity of 1.0.
A diffuser 7 is arranged in or below the immersion bed, and a treated water outlet 16 is provided in the sedimentation section 10 around the immersion bed 6. A biological treatment device for wastewater, characterized in that it is formed by: