JP2529804B2 - Sewage treatment device using packed bed - 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 using a packed bed capable of performing advanced treatment of sewage using a limited space.

[0002]

2. Description of the Related Art The social demand for advanced treatment of sewage is increasing. The immediate targets of this advanced treatment are nitrogen and phosphorus for preventing eutrophication of water bodies, and also BOD, COD, SS and the like. Of these, BOD and SS can be removed to a large extent by "biofilm filtration" in which the water to be treated flows downward from the top of the aerobic packed bed. It is preferable to use an anaerobic packed bed and an aerobic packed bed for performing nitrification denitrification, and the process for this is also researched.

FIG . 2 shows a typical example of an apparatus studied for performing such nitrification denitrification. An aerobic tank 21 and an anaerobic tank 22 filled with particles having a specific gravity of more than 1. Is provided independently, and first, the water to be treated is allowed to flow downward in the aerobic tank 21.
The anaerobic tank 22 is used to remove the water to be treated from below the aerobic tank 21 by the pump 23.
Is a system in which the anaerobic tank 22 is allowed to flow downward in addition to being transferred to the upper part of the. However, the conventional sewage treatment equipment as shown in FIG. 2 requires a large area as a site, and it becomes very difficult to secure an extra space for advanced treatment at an existing sewage treatment plant in an urban area. Therefore, there is a problem that it cannot be easily adopted. Further, this sewage treatment device also has a problem that a large capacity pump 23 is required.

Further, as shown in FIG. 3 , the inside of the tank 24 is filled with particles having a specific gravity of less than 1, the lower part is an anaerobic layer 25, the upper part is an aerobic layer 26, and the water to be treated is an upward flow. A part of the treated water that flows out from the upper part of the tank 24 is pumped 27
The so-called “nitrifying solution circulation system” for circulating the anaerobic layer 25 has also been studied. The apparatus of FIG. 3 has an advantage that the installation space is relatively small, but there is also a problem that a large capacity pump is required for circulating the nitrifying solution.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and treats sewage using a packed bed capable of performing advanced treatment of sewage without requiring a large space or a large capacity pump. It has been completed to provide a device.

[0006]

SUMMARY OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, has a structure in which the inside of a tank having a support layer at the bottom is introduced into the packed bed side by means of vertical partition walls having circulation portions at both upper and lower ends. Divided into water channels, the upper part on the packed bed side is filled with particles with a relatively small specific gravity, and a diffuser pipe is installed to form an aerobic tank. It is characterized in that an anaerobic tank is formed by filling large particles and the height of the upper end of the vertical partition wall is variable.

[0007]

EXAMPLES The present invention will be described below in more detail with reference to Examples.
I will tell. FIG. 1 is a diagram showing an embodiment of the present invention.
The inside of the is separated by the vertical partition wall 2 between the packed bed side and the inflow channel 13 side.
It is divided into This vertical partition wall 2 has a circulation part 3 at its lower end.
Besides, it also has a circulation part 14 at the upper end. This vertical
The height h of the flow section 14 at the upper end of the bulkhead 2 is variable and filling
It became possible to control the amount of inflow into the inflow channel 13 from the layer side.
ing. A supporting layer made of gravel or the like on the bottom of the tank 1
5 is formed, and the specific gravity is
Has a relatively small value of 1 to 1.5 and a diameter of 5 to 15 mm.
When filling particles such as gel particles and anthracite
In addition, an aeration pipe 6 is provided below the packed bed to form an aerobic tank 7.
I am doing it. The specific gravity of the lower part on the packed bed side is 1.5-2.
5, a lightweight aggregate with a diameter of 2-10 mm, which is relatively large.
The anaerobic tank 8 is filled with particles such as crushed stone. What
For cleaning the packing layers 7 and 8 at the bottom of the support layer 5,
Air + water piping 11 is provided.

The packing layer of the present invention having the above-mentioned structure is used.
In the sewage treatment equipment that was used,
The water in the aerobic tank 7 floats, and this acts as a driving force for the packed bed.
Circulation in which the treated water floats on the side and descends on the inflow channel 13 side
Cause The amount of circulation from the packed bed side to the inflow channel 13 side
By changing the height h of the flow section 14 at the upper end of the partition wall 2.
Can be adjusted. Water to be treated and nitrification treated water are mixed
The upward velocity of the combined liquid is limited to 500 m / day.

Now, the treated water which is the supernatant water of the final settling tank
Supply methanol, which is the hydrogen donor required for denitrification.
Water supplied to the tank body 1 after passing through the aerobic tank 7,
Both descend the inflow channel 13 and pass through the circulation section 3 and the support layer 5.
First, enter the anaerobic tank 8. Here it is attached to the packed bed
Nitrate nitrogen is denitrified by the existing denitrifying bacteria to produce nitrogen gas.
Be removed. At this time, BOD is a hydrogen supply for denitrification.
Used as a part of the donor and removed, SS is anaerobic tank 8
Trapped and removed by the packed bed. Passed anaerobic tank 8
The water to be treated next enters the aerobic tank 7 and flows upward in the aerobic tank 4.
Then flow. During this time, the Kjeldahl nitrogen in the water to be treated is
Is converted to nitrate nitrogen, and part of it is treated as final treated water.
Part of it is discharged from the inflow channel 13 as nitrification treated water.
It is circulated in the anaerobic tank 8. At a rate of about once a day
Filling by supplying cleaning water and air from the air + water pipe 11
The layers are backwashed and washed, but the aerobic tank 7 and the anaerobic tank 8 are not filled.
Due to the different specific gravities of the
And separate and settle.

The sewage treatment apparatus using the packed bed of the present invention is
There is an advantage that the installation space can be reduced, and about 80%
Achievement of denitrification rate, which is different from the devices in Fig. 2 and Fig. 3.
No need for a pump for circulating nitrifying solution, final treatment
Since water is aerobic, it is necessary to add oxygen to the treated water.
No need for equipment, and air + water piping 11 for layer cleaning
There are advantages such as that one set is enough.

[0011]

As described in detail above, the present invention
Compared to conventional equipment, sewage treatment equipment using packed beds is installed.
Installation space can be reduced, so installation in a limited space
can do. In addition, a large-capacity pump like the past
It is not necessary and the stability of the packed bed during backwashing is high.
There are advantages. Further, according to the present invention, the denitrification rate of about 80%
And to provide oxygen to the treated water.
It has the advantage that no equipment is required. Therefore, the present invention is a conventional problem.
As a sewage treatment device using a packed bed that solves the problems,
There are extremely large areas that contribute to the development of the industry.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

FIG. 3 is a cross-sectional view showing another conventional example.

[Explanation of symbols]

 1 Tank Body 2 Partition 3 Flow Section 5 Support Layer 6 Diffusing Pipe 7 Aerobic Layer 8 Anaerobic Layer 11 Air + Water Pipe 13 Inflow Channel 14 Flow Section

Claims (1)

(57) [Claims] 1. The inside of a tank having a support layer at the bottom is placed on both upper and lower sides.
A vertical partition with a circulation section at the end allows the packed bed side and inflow channel
The specific gravity is relatively small in the upper part on the packed bed side.
The aerobic tank is filled with fine particles and provided with a diffuser pipe.
Grains that have a relatively high specific gravity in the lower part on the packed bed side.
The anaerobic tank is formed by filling the child and the upper end of the vertical partition
The packed bed is characterized in that the height of the distribution part is variable.
Sewage treatment equipment used.