JPS6323999Y2 - - Google Patents

Description

[Detailed description of the invention] This invention can increase the BOD load by circulating and cleaning the medium with biofilm attached, and the tank volume and
The present invention relates to a sewage treatment system that enables a reduction in site area and is easy to maintain and manage without clogging or backwashing equipment.

Currently, the standard activated sludge method is the most popular sewage treatment equipment, but this treatment method has a BOD volumetric load of only 0.3 to 0.8 Kg/m for ³ days, and requires a tank for effective treatment. The disadvantage was that the volume and site area were larger. Furthermore, the floating method has problems that are difficult to solve in terms of solid-liquid separation, and the biofilm method has the drawbacks of clogging between media and the need for special backwashing equipment.

This idea solves the above drawbacks, and by circulating and cleaning the medium with biofilm attached, it is possible to dramatically increase the BOD load and reduce the tank volume and site area.
In addition, there is no need to worry about bulking, the amount of sludge generated is small, and it also prevents clogging between media, does not require a backwashing device, is easy to maintain, and has an extremely wide range of sludge concentrations that can be treated. The purpose is to provide processing equipment.

An embodiment of this invention will be described below with reference to the drawings.

As shown in FIG. 1, the first embodiment of this invention has an aeration processing section 1 and a precipitation processing section 2 for further precipitating the processing liquid treated in the aeration processing section 1.

The aeration treatment section 1 includes a lower hopper-shaped treatment tank 3, and the treatment tank 3 is filled with sand, anthracite, glass spheres, etc., which are preferably approximately spherical and do not flow with aeration by an aeration device 5, which will be described later. The medium 4, the air diffuser 5 disposed in the middle of the four layers of the medium, and the medium 4 near the bottom of the fourth layer by the operation of the drive unit 6 extending from the bottom of the processing tank 3 to the top of the fourth layer of the medium.
It has a screw conveyor (medium circulation device) 7 that pulls out and circulates it to the upper liquid part 8 above the four layers of media,
This screw conveyor 7 functions to regenerate and circulate the medium 4 to which the microbial biofilm is attached. The upper liquid part 8 is formed above the four layers of the medium, and the biofilm peeled off from the medium 4 and the wastewater a to be treated are transferred to the aeration device 5.
It functions to make air float.

According to the above configuration, the wastewater a to be treated flows from the lower part of the treatment tank 3 into the medium 4 layer, and rises as shown by arrow A while BODSS etc. are removed by the microorganisms attached to the medium 4, and then The microorganisms separated from the medium 4 remain in the upper liquid section 8, and are subjected to activated sludge treatment by air supplied from the aeration device 5. This activated sludge mixture flows out from the upper part of the treatment tank 3 and is supplied to the settling tank 2a of the settling section 2. After sufficient solid-liquid separation, the supernatant liquid is discharged as treated water, while the settled sludge is treated as surplus sludge. removed from the system as

In this way, in this design, sewage treatment is performed using a microbial membrane attached to a small spherical medium, and its specific surface area is greatly increased compared to conventional fixed beds, resulting in a dramatic increase in the load per volume (BOD load). 3 to 10Kg/m ³ days), and the tank volume and site area can be significantly reduced accordingly. In addition, since it is a biofilm method, there is no need to worry about bulking, and there are advantages such as the amount of sludge generated is small and it is resistant to load fluctuations. Further medium 4
It is preferable to use a spherical one, so that the contact area between the media 4 is minimal and microorganisms can effectively adhere to the surface, and the gaps between the media 4 are even, so the movement of liquid and gas is uniform. In particular, the air from the air diffuser 5 rises between the media 4, uniformly supplies oxygen to the microorganisms attached to the media 4, and at the same time promotes the exfoliation of enlarged biofilms. In particular, in this invention, the air diffuser 5 is placed in four layers of media that do not flow due to the air diffused by the air diffuser 5, so the air supplied from the air diffuser 5 rises through the gap between the media 4. . For this reason, the air is fragmented,
Since the rate of rise is slow and the biofilm attached to the medium 4 is directly contacted, the efficiency of oxygen supply is very high. Furthermore, since the air diffuser 5 supplies air into the four layers of the medium, clogging due to enlargement of the biofilm attached to the medium 4 can be prevented.

On the other hand, the medium 4 at the bottom of the treatment tank 3 is pulled out by the screw conveyor 7 located in the center and lifted to the upper liquid part 8 above the medium 4 layer, and at this time, the organisms attached to the surface of the medium 4 are removed. The film is peeled off and removed.
Circulated by its own weight. Therefore, since the medium 4 is cleaned and circulated in this process, anaerobic formation and clogging can be prevented, and special backwashing equipment is not required, and advanced maintenance technology is not required at all. The device can be made more compact. Furthermore, in the upper liquid part 8 of the treatment tank 3, effective activated sludge treatment is carried out by the detached microorganisms and diffused air. is extremely good, making sludge treatment extremely easy.

The wastewater to be treated in this embodiment can be applied to a very wide range of wastewater concentration, such as secondary sewage treatment, tertiary treatment, clean water treatment, and industrial waste water treatment.

As described above, according to this invention, the BOD load can be dramatically increased, the site area can be significantly reduced, there is no need to worry about bulking, the amount of sludge generated is small, and the clogging of the media can be prevented and reversed. It has excellent practical effects such as no washing equipment is required, easy maintenance and management, and an extremely wide range of wastewater treatment.

[Brief explanation of the drawing]

FIG. 1 shows a schematic configuration diagram of an embodiment of this invention. 3... treatment tank, 4... medium, 5... aeration device,
7...Medium circulation device.

Claims (1)

[Scope of utility model registration request] A lower hopper-shaped treatment layer, a medium filled in this treatment layer that does not flow due to aeration by an aeration device described below, an aeration device disposed in the middle of this media layer, and a bottom portion of the media layer. A screw conveyor that lifts and circulates the medium located nearby to an upper liquid section, which will be described later, and a biological film formed above the medium layer in the treatment layer and separated from the medium are aerated by the aeration device. The upper liquid part is introduced into the lower part of the medium layer and flows upward through the medium layer, and the sewage that stays in the upper liquid part and a part of the liquid in the upper liquid part are precipitated. A sewage treatment device comprising a sedimentation treatment section that discharges treated water as treated water.