JPS6244798Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a sprinkler bed device.

The sprinkled bed method is extremely energy efficient as it does not require aeration operations like the activated sludge method.
It has a fatal disadvantage of inferior quality of treated water compared to the activated sludge method, and the trickling bed method is no longer being used at all in recent sewage treatment plants.

The quality of the treated water is poor because the conventional crushed stone sprinkler bed method uses materials with large particle diameters of 5 to 8 cm, resulting in a small surface area and a low amount of bed microorganisms. However, when a material with a small particle size is used, the pore size becomes small, which causes clogging, which leads to poor ventilation, which is a serious drawback. In other words, using a material with a small particle size could theoretically increase the surface area and improve the quality of treated water, but it was previously thought to be impossible to put into practical use because it would inevitably lead to bed clogging. .

The present invention is based on a novel idea and provides a sprinkler bed device that completely overcomes such contradictions.

That is, in the present invention, as shown in an embodiment in the drawings, porous water-permeable bodies 2 such as nets are provided in multiple stages in a watering floor tank 1, and granules with a specific gravity of less than 1.0 are placed on the upper part of each of the porous water-permeable bodies 2. This sprinkler bed apparatus is characterized in that solids 3 are filled so as to form spaces 4, and air circulation ports 5 are provided in each of these spaces 4.

Note that the shape of the granular solid 3 may be arbitrary, as long as it is capable of independent movement.

Hereinafter, the above embodiment will be explained in detail.
In the sprinkler floor tank 1, porous water-permeable bodies 2 such as nets and perforated plates are arranged in multiple stages. The porous water-permeable body 2 is filled with granular solids 3 that float on water, such as wood chips, styrofoam, and polypropylene.

The particle size of the granular solid 3 is about 0.1 to 1 cm, and the particle size of the material used in conventional sprinkler bed equipment is 5 to 1 cm.
One of the important points is to make the material much smaller than 8 cm, which increases the surface area of the material and significantly increases the microbial concentration in the floor.
Good treated water quality equivalent to the activated sludge method can be obtained, and it is also possible to remove SS in the raw water (with conventional sprinkler bed equipment, the material is large, so SS in the raw water can be removed).
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In the present invention, it is an essential requirement that the granular solids 3 be filled so that a space 4 remains, but the thickness of the granular material layer made of the granular solids 3 is determined by the microorganisms in the material layer due to natural ventilation. In order to supply oxygen to the
If the height is more than 50 cm, natural ventilation will be difficult. In view of this, in a preferred embodiment of the present invention in which the granular solid is of small particle size, the granular material layer is arranged in multiple stages with the space 4 interposed therebetween.

Next, to explain the manner in which wastewater is treated using the device of the present invention, organic wastewater 8 such as sewage is sprinkled from the water sprinkling section 6 at the top of the water sprinkling bed tank 1, and after flowing down in the layer of granular material with small particle size. After repeating several times the cycle of dripping into the air in the space 4 and further flowing down into the lower granular material layer,
The treated water 9 from which BOD has been removed flows out from the treated water outlet 7.

The oxygen necessary for the microorganisms living on the surface of the granular solid 3 easily enters the granular material layer because the air flowing in through the air flow opening 5 has a shallow thickness of about 10 cm and has low ventilation resistance. It does not require any power (such as a blower or fan).

However, as the treatment continues, the water flow resistance of the uppermost granular material layer increases due to the SS and proliferating microorganisms in the organic wastewater 8, but in the present invention, the granular solids 3 float on the water. Because it has the characteristics
When the granular material layer begins to be submerged in water due to an increase in water flow resistance, the granular solids 3 rise to the surface, and as a result, the SS and excessively proliferating microorganisms that had been captured until then are separated and fall to the granular material layer below with water. I'm going to go. A similar phenomenon occurs in this stage, and the stage sequentially moves to the next lower stage. In this way,
No matter how high the concentration of SS and BOD is, in the present invention, the granular material layer will never be clogged, and the processing can continue extremely smoothly and efficiently.
Note that the upper material layer has a lower BOD than the lower material layer.
Although the load and the SS load become higher, increasing the particle size of the granular solid 3 toward the upper stage makes it possible to reduce the increase in water flow resistance of the material layer, which is extremely convenient.

Thus, the SS and proliferating microorganisms captured in the material layer are separated in a solid-liquid separation step 10, such as a settling tank or a filter, which is provided subsequent to the treated water outlet 7.

According to the present invention as described above, the following important effects can be obtained, and the problems of conventional sprinkler bed devices can be completely solved.

Since the granular solids are arranged in multiple stages with spaces between them, ventilation resistance is low even when using granular solids with small particle diameters, and oxygen can be easily supplied through natural ventilation, resulting in a significant improvement in the quality of treated water. It becomes possible.

Since floating particles are used in the material, the material self-cleans automatically without requiring any power, and troubles such as clogging do not occur.

Since the material is made of extremely light particles and these are exposed to the air, the strength of the porous water-permeable body that supports the floor can be reduced, resulting in a significant reduction in the manufacturing cost of the device. In addition, the floor and walls do not need to be made of iron plates or the like and can be simply sheet-shaped, so the construction cost can be the lowest compared to all conventionally known biological treatment equipment.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of an embodiment of the present invention. 1... Watering bed tank, 2... Porous water permeable body, 3...
Granular solid, 4... Space, 5... Air flow opening, 6
... Water sprinkling section, 7 ... Treated water outlet, 8 ... Organic wastewater, 9 ... Treated water, 10 ... Solid-liquid separation step.

Claims (1)

[Claims for Utility Model Registration] 1. Porous water-permeable bodies are arranged in multiple stages in a tank, and a granular material layer consisting of granular solids with a specific gravity of less than 1.0 is formed on each of the porous water-permeable bodies, as well as a space above the layer. A water sprinkling floor device in which air circulation ports are provided in each space. 2. The device according to claim 1, wherein the particle size of the granular solid is gradually decreased from the upper stage to the lower stage. 3. The device according to claim 1 or 2, wherein the particle size of the granular solid is 0.1 to 1 cm. 4. The device according to claim 1, 2, or 3 of the utility model registration claim, wherein the layer thickness of the granular material layer is 10 to 20 cm.