JPH0222072Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an improvement of a sewage treatment device that returns a mixed liquid containing biofilm detached in an aerobic treatment chamber to a sedimentation separation chamber or an anaerobic treatment chamber. It is.

[Conventional technology]

Traditionally, activated sludge method was the most common biological treatment of sewage, but in recent years activated sludge has been fixed on a certain kind of support (bed) to form a biofilm.
The biofilm method, which purifies wastewater by bringing it into contact with wastewater, is becoming popular. Among these, the contact aeration method, in which the floor is immersed in water, is easy to maintain and is an excellent method that can withstand rapid changes in load and temperature. On the other hand, blockage of the floor due to excessive biofilm deposition and deterioration of treated water quality due to exfoliation are unavoidable, so aerobic treated water containing exfoliated sludge is constantly or intermittently treated in a sedimentation separation chamber or anaerobic. A method is adopted in which the separated sludge is sent back to the treatment room and separated and removed by sedimentation.

Methods for returning aerobic treated water to the sedimentation separation room include natural return by restoring the liquid level as described in "Structural Standards and Disassembly of Human Waste Septic Tanks (1980 Edition)" (Japan Building Center), page 134; There is a forced return using an air lift pump.

Additionally, there are the following publications:

1 Utilizing lift-up of the liquid level 1 Publication of Utility Model Publication No. 1988-10800 2 Publication of Publication of Japanese Utility Model No. 60-21394 3 Publication of Publication of Publication of Japanese Utility Model No. 39118-1984 4 Publication of Publication of Publication of Japanese Utility Model No. 60-4760 5 Publication of Japanese Utility Model Publication No. 59-93789 Publications 6 Utility Model Application Publication No. 59-93789 7 Utility Model Application Publication No. 58-86298 8 Utility Model Application Publication No. 58-31096 9 Utility Model Application Publication No. 57-199098 10 Utility Model Application Publication No. 57-177598 2 Utilizing water flow 1 Japanese Utility Model Publication No. 58-6555 2 Publication of Utility Model Publication No. 57-14952 3 Due to the rise and fall of the water surface 1 Publication of Utility Model Publication No. 58-17674 4 Due to forced air lift 1 Publication of Utility Model Publication No. 59-44592 2 Utility Model Publication Publication No. 58-156591 5 Based on natural air lift (technology closest to the present invention) 1 Publication of Utility Model Publication No. 58-26074 2 Publication of Publication of Utility Model No. 60-10714 [Problems to be solved by the invention] On the other hand, the above-mentioned invention or The two methods, namely, the method using liquid level lift-up shown in 1 (Fig. 5) and the method using water flow shown in 2 (Fig. 3), are designed to prevent the inclination of the tank during installation, the misalignment of the air diffuser, There was a problem in that quantitative return was not possible due to uneven water flow due to blockage of the contact material, etc. Further, the method shown in 3, which involves raising and lowering the water surface, has similar problems. On the other hand, those using air lift (Fig. 4, Fig. 6)
is a quantitative but small discharge amount, for example 1
/ minute, it is difficult to adjust the air volume.
There was a problem that a stable discharge amount could not be obtained for a long period of time. For example, Japanese Utility Model Publication No. 58-26074 uses an air lift system for natural return (FIG. 6), but it is difficult to control the amount of return. Also, Jiko 60
Publication No. 10714 also uses airlift natural return, which is almost the same method as the previous issue, but it is impossible to constantly return small quantities because the return is determined by attaching and detaching the attachment.

The present invention was developed in view of the above-mentioned drawbacks, and provides a sewage treatment system that can return a small amount of aerobically treated water to a sedimentation separation chamber or an anaerobic treatment chamber without any other power, and that does not vary in the amount of returned water at a low cost. It is intended to provide.

[Means for solving problems]

The structure of the present invention to achieve the above purpose is as follows:
To explain based on FIG. 1 and FIG. 2 corresponding to the embodiment, the present invention has a sedimentation separation chamber and/or an anaerobic treatment chamber 1, an aerobic treatment chamber 2, a precipitation chamber 3, and a disinfection chamber 4 arranged in this order. In the sewage treatment equipment 20, a flow rate adjustment container 7 that can be adjusted in the vertical direction is installed at the top of the riser pipe 6 whose lower end opening faces directly above the aeration device 5 disposed in the aerobic treatment chamber 2. Attachment, technical measures are taken in which the container 7 is provided with a wide weir 9 for returning excess water, a rectification baffle 10, and a return water measuring weir 11.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of a flow rate adjustment container showing an embodiment of the present invention, and FIG. 2 is a sectional view showing the installed state of the flow rate adjustment container.

20 is a precipitation separation chamber and/or an anaerobic treatment chamber 1;
This sewage treatment equipment consists of an aerobic treatment chamber 2, a sedimentation chamber 3, and a disinfection chamber 4, each of which is equipped with a floor 17 and an air diffuser 5.

A riser pipe 6 whose lower end is open is provided almost directly above the air diffuser 5 for supplying oxygen to the aerobic treatment chamber 2 . Most of the air discharged from the aeration device 5 is used as an energy source for supplying oxygen to the aerobic treatment chamber 2 and generating water flow, but some of it is used as an energy source for supplying oxygen to the aerobic treatment chamber 2 and for generating water flow, but some of the air is used for supplying oxygen to the aerobic treatment chamber 2 and as an energy source for generating water flow. The air lift phenomenon occurs in the riser pipe 6 due to the difference in specific gravity between the inside and outside of the pipe. As a result, the aerobically treated water is pumped into the flow rate adjustment container 7 integrated with the riser pipe 6. Inside the flow rate adjustment container 7, a wide weir 9 for returning excess water and a measuring weir 11 for checking the amount of returned water are provided, sandwiching the rectification baffle 10. Due to the difference in the lengths of these weirs, the water level in the flow rate regulating container 7 is determined by the wide weir 9, and even when the amount of water pumped in the riser pipe 6 changes, it maintains a substantially constant water level. As a result, the water head at the return water metering weir 11 becomes constant, making it possible to quantitatively return aerobic treated water to the sedimentation separation chamber or anaerobic treatment chamber 1 (not shown). For this purpose, it is desirable that the weighing weir 11 be a triangular weir.

In general, the amount of water pumped by an air lift pump depends on the immersion depth.
It is known that it is greatly influenced by Hs/Hs+H (submergence rate), which is expressed by Hs and head H. Also, under normal conditions, there is no need to increase the head H, so immersing the riser pipe 6 to the top of the diffuser 5 as in the present invention is effective in keeping the water immersion rate constant. . Further, since the flow rate adjusting container 7 can be easily moved up and down using the adjusting screw 8, it is possible to easily deal with clogging of the air diffuser 5, etc.

7 and 8 are perspective views showing other embodiments of the present invention. In FIG. 7, the wide weir 9 shown in FIG. It is possible to obtain a stable amount of water returned to the treatment chamber 2. 8th
In the figure, an orifice 18 is provided in place of the buttful 10. In general, the amount of water θ flowing out from an orifice is determined by the relationship between the cross-sectional area A of the orifice and the water level H as Q=A・C√2g (g: gravitational acceleration, C: flow rate coefficient). By changing the height, the amount of returned water can be adjusted, and as in FIG. 7, a stable amount of returned water can be obtained even when the amount of water pumped in the riser pipe 6 is excessive.

[Effect of idea]

In the present invention, a flow rate adjustment container is attached to the top of a riser pipe whose lower end opening is directly above an aeration device installed in an aerobic treatment room, and a weir for returning excess water is installed in the container. Since the configuration is equipped with a rectifying butthole and a return water metering weir, a small amount (1/2
This has the effect of making it possible to provide a wastewater treatment equipment at a low cost, which allows for a return of approximately 30 minutes (about 30 minutes), and has an extremely small variation in return amount (coefficient of variation = standard deviation/average value x 100 of 3% or less).

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a schematic sectional view showing an embodiment of the present invention, FIGS. 3 to 6 are schematic sectional views showing a conventional embodiment, and FIG. , FIG. 8 is a perspective view showing another embodiment of the present invention. Explanation of symbols, 1...Sedimentation separation chamber, 2...Aerobic treatment room, 3...Sedimentation chamber, 4...Disinfection room, 5...Air diffuser, 6...Riser pipe, 7...For flow rate adjustment Container, 8...Adjusting screw, 9...Wide weir, 10...Bassful, 11...Measuring weir, 12...Sludge, 13...
...Advection tube, 14...Airlift Batsuful, 15...
...air lift pipe, 16...adjustment full, 1
7...floor, 18...orifice, 20...sewage treatment equipment.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a sewage treatment system consisting of a sedimentation separation chamber and/or an anaerobic treatment chamber, an aerobic treatment chamber, a sedimentation chamber, and a disinfection chamber arranged in this order, A flow rate adjustment container is attached to the top of the riser pipe whose lower end opening is directly above the air diffuser, and the container is equipped with a weir for returning excess water, a rectifying buttful, and a return water measuring weir. A sewage treatment device featuring: 2. The sewage treatment device according to claim 1, wherein the flow rate adjusting container is attached to the riser pipe so as to be adjustable in the vertical direction. 3. The sewage treatment device according to claim 1, wherein the surplus water return weir is a wide weir. 4. The sewage treatment device according to claim 1, wherein the lower end opening of the riser pipe is located near the air diffuser.