JPH0985269A - Sewage treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the discharge of a suspended substance such as a scum to the outside of an apparatus even when the inflow amt. of sewage per a unit time fluctuates suddenly. SOLUTION: Sewage flows from an aeration decomposition chamber 10 to a sedimentation chamber 19 through an opening part 14 provided in the vicinity of the water surface of a partition wall 13 partitioning both chambers 10, 19 and a filter 17 is provided to the opening part 14 on the side of the aeration decomposition chamber 10 in a detachable manner and a scum skimmer 22 and an air lift pump 25 cooperating therewith are provided on the side of the sedimentation chamber 19.

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, and more specifically, it reliably captures suspended matter mixed in sewage before reaching the disinfection chamber, which is the final stage of the sewage treatment apparatus. The present invention relates to a sewage treatment apparatus that can improve the water quality of discharged water by removing it.

[0002]

2. Description of the Related Art In a conventional sewage treatment apparatus, for example, a contact aeration type septic tank, the sewage flowing into the tank from the sewage inlet is
While passing through the solid-liquid separation settling room or the anaerobic filter bed room, the aeration decomposition room, the precipitation room (precipitation room), etc., the treatment is repeated step by step, and the supernatant liquid of the precipitation room is taken by the overflow weir. Then, it is made to flow into the disinfection chamber and is sequentially drained from the drain port provided in the disinfection chamber.

However, the amount of sewage flowing into the tank from the sewage inlet per unit time is not always constant, and tends to be concentrated in the morning hours when the domestic wastewater is most used.
Therefore, the advection of sewage in the tank becomes unstable, and a sudden rapid flow of water occurs.At that time, a large amount of sewage in the aeration decomposition chamber and the sedimentation chamber is also discharged outside the tank through the disinfection chamber. Is done.

At this time, in the aeration decomposition chamber and the sedimentation chamber, the biofilm adhering to the filter bed, the tank wall, or the like is peeled off, or the floating substances in the sedimentation, the sludge that has been separated by sedimentation, and the peeled biofilm are separated. The microscopic loose bodies (collectively referred to as "scums" hereinafter) are floated on the surface of the water by being swirled up by the force of the water flow and flow out of the disinfection chamber to the outside of the tank.

In this way, the settling chamber, which is supposed to be a room originally designed to naturally settle the scum and the like in the sewage and send only the supernatant into the disinfecting chamber, is actually the scum and the like. Are easily floated and may be mixed in the discharged water and discharged. Since such scums have a high BOD value, it is necessary to capture and eliminate them as much as possible to maintain the quality of the discharged water. there were.

Therefore, various measures have been conventionally made to solve this problem. For example, in Japanese Utility Model Publication No. 1-4469, a filter made of a fibrous body is arranged in the middle of the sedimentation chamber. However, a technique is disclosed in which scum or the like from the aeration decomposition chamber is filtered and captured to prevent the scum from being mixed into the discharged water.

[0007]

However, in the case of this prior art, since the filter provided in the clarification chamber is bulky, the effective capacity of the clarification chamber is reduced to that extent and its function is deteriorated. However, since the filter density is high and clogging is likely to occur, a backwash facility was also required.

This backwashing equipment is a method for washing the filter by rotating the air diffuser pipe used in the aeration decomposition chamber at any time with the upper end as an axis to diffuse air from the lower portion of the sedimentation chamber. However, in order to completely remove scum floating in the upper part of the sedimentation chamber after backwashing, the filter should be raised to the surface of the water to prevent advection of scum to the disinfection chamber and wait for re-sedimentation in the sedimentation chamber. However, there is a problem that it takes time to restore the function of the septic tank.

The present invention solves the above-mentioned problems in the treatment of scum and the like, and can reliably prevent the scum and the like from being discharged outside the tank by following the influent wastewater that fluctuates greatly. The purpose is to provide a device.

[0010]

The sewage treatment apparatus according to the first aspect of the present invention is a sewage treatment apparatus having at least an aeration decomposition chamber, a sedimentation chamber and a disinfection chamber in the advection direction. Advection to the sedimentation chamber is made possible by the opening provided near the water surface of the partition that separates both chambers.A filter is removably attached to the aeration decomposition chamber side of this opening, and it is attached to the sedimentation chamber side. Is provided with a scum skimmer and an air lift pump that works in conjunction with the scum skimmer. ”This achieves the above object.

According to the second aspect of the present invention, there is provided a sewage treatment apparatus having at least an aeration decomposition chamber, a clarification chamber and a disinfection chamber in the advection direction. Is divided into a first simmering chamber and a second simmering chamber, and an inclined surface inclined upward toward the first simmering chamber is formed in the middle of the partition wall and an opening is formed in this inclined surface. Provided, advection from the first clarification chamber to the second clarification chamber is enabled by this opening, a filter is mounted on the first clarification chamber side of the opening, and on the second clarification chamber side The scum skimmer and an air lift pump that works together with the scum skimmer are additionally provided. "This also achieves the above object.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a wastewater treatment apparatus of the present invention will be described in detail with reference to the drawings. In addition, the example shown in the drawings shows a case where the sewage treatment apparatus of the present invention is adopted in a small household combined treatment septic tank.

FIG. 1 is a longitudinal sectional view showing the entire structure of an example of the sewage treatment apparatus according to the first aspect of the invention.

In the figure, 1 is an anaerobic filter bed first chamber, 2 is a first filter medium, 3 is a first partition plate, 4 is a first advection port, 5 is an anaerobic filter bed second chamber, and the second chamber is also the same. It has a filter medium 6, a second partition plate 7, and a second advection port 8.

Numeral 9 is a sewage intake, from which sewage enters the anaerobic filter bed first chamber 1, passes through the first filter medium 2 and rises. Then, it enters the anaerobic filter bed second chamber 5 through the first advection port 4 provided near the upper end of the first partition plate 3. Similarly, after passing through the second filter medium 6, it rises. Then, it is admitted to the aeration decomposition chamber 10 from the second advection port 8 provided near the upper end of the second partition plate 7.

Reference numeral 11 is a contact material, and 12 is an air diffuser, both of which are incorporated in the aeration decomposition chamber 10. Air diffuser 12
Is connected to a blower (not shown), and fine air bubbles are ejected from the nozzle by compressed air from the blower to form an upward flow of sewage in the room. When this rising water flow reaches the water surface, it becomes a descending water flow, thereby forming a clockwise swirling flow in the aeration decomposition chamber 10.

On the other hand, when the biofilm adhering to the surface of the contact material 11 is thickened, it is separated by this swirling flow, and a part of the biofilm adheres to the bottom of the anaerobic filter bed 5 together with scum and the like. As it settles and accumulates, the rest turns.

Reference numeral 13 is a partition wall for partitioning the aeration decomposition chamber 10 and a sedimentation chamber, which will be described later, and the lower end of the partition wall is connected to the bottom wall of the tank to define both chambers. Further, the upper edge of the partition wall 13 projects about 15 to 20 cm from the water surface, and a slightly larger opening 14 having a square shape when viewed from the front is provided in the vicinity of the water surface, and from the aeration decomposition chamber 10 to the sedimentation chamber. Advection is made possible by this opening 14.

FIG. 2A is a partially cutaway exploded perspective view showing the opening 14 and the filter attached to the opening 14, and FIG. 2B shows only the inner filter. It is a perspective view.

On the side of the aeration decomposition chamber 10 of the opening 14, a frame-shaped holding frame 15 having a size larger than that of the opening 14 and lacking the upper edge is provided so as to project between the wall surface of the partition wall 13. Further, a fitting insertion groove 16 into which a filter described later can be fitted and removed is formed.

Reference numeral 17 denotes a filter, which is formed by laminating non-woven fabrics made of polyethylene fibers and having a thickness of about 0.5 to 1 mm, and forming a plate shape having a thickness of about 5 mm. The outer peripheral edge in contact with the groove surface of the fitting groove 16 is an edge frame 1 made of rubber sponge.
By edging at 8, the edge portion is reinforced, the fitting / removal is facilitated, and the packing function is provided, and scum in the dirty water enters from between the groove surface of the fitting insertion groove 16 and the edge frame 18. It is considered not to do so.

This filter 17 must be provided on the side of the aeration decomposition chamber 10 of the opening 14. If the filter is provided on the side of the sedimentation chamber, scum or the like is easily mixed in the sedimentation chamber when the filter is replaced. Also, in order to maintain the water quality by regularly replacing the filter and improve the workability of the replacement,
The upper edge should be projected from the surface of the water, and that part should be used as a grip for replacement.Also, if you have prepared multiple new or cleaned filters in advance, replacement should be done instantly. You can

Reference numeral 19 is a sedimentation chamber, 20 is an overflow weir, 21 is a disinfection chamber, and 22 is a scum skimmer. This scum gap 22
Is located at a position about 5 mm lower than the water surface of the sedimentation chamber 19 so as to face the overflow weir 20.
It is attached to the side.

FIG. 3 is a plan view of only the main part showing the inside of the sewage treatment apparatus shown in FIG. 1 with the inspection lid removed.

The scum skimmer 22 is shown in FIGS.
As also shown, the scooping part 23 having a rectangular shape in a plan view and having a funnel shape, and the suction pipe 2 suspended from substantially the center part thereof.
It consists of 4. The longitudinal dimension of the ladle 23 is
It is made about 1/2 of that of the overflow weir 20, so that scum etc. can be sucked from the entire water surface as much as possible.

An air lift pump 25 is composed of a pumping pipe 26, an air pressure feeding pipe 27 connected to the lower end of the pump 26, and a compressed air source such as an air adjusting valve and a compressor (not shown), which is almost in contact with the scum skimmer 22. Are arranged.

The scum skimmer 22 and the air lift pump 25
Is a function that works in cooperation with each other.
As shown in (c), if the lower end of the suction pipe 24 is connected to the middle of the pumping pipe 26 and the air lift pump 25 is driven,
5 to 10 liters of sewage can be pumped from the pumping pipe 26 at all times.

In this way, the dirty water collected by the scooping portion 23 of the scum skimmer 22 is sucked into the suction pipe 24 by the drive of the air lift pump 25, and is pumped up to the upper part of the pump pipe 26.

28, 28 are return pipes, 29 is aeration decomposition chamber 1
0 is a pumping pipe of a return air lift pump for settling / accumulating scum and the like, and the returning air lift pump includes this pumping pipe and a compressed air source such as an air pressure feeding pipe, an air adjusting valve and a compressor. Consists of. In addition, if this air lift pump is operated at all times and constantly returns a fixed amount, for example, about 2 to 5 times the inflowing wastewater into the sedimentation chamber 19, the denitrification effect of the wastewater is also improved.

Thus, the sewage of the scum skimmer 22 pumped up to the upper portion of the pumping pipe 26 is laterally drawn at the sideways cheese and sent to the return pipe 28 and the pumping pipe 29.
It joins with the return scum and the like of the aeration decomposition chamber 10 that has been pressure-fed by and is returned to the anaerobic filter bed first chamber 1.

The main operation of the sewage treatment apparatus according to the first aspect of the present invention will be summarized below. The anaerobic filter bed first chamber 1
The sewage treated in the anaerobic filter bed second chamber 5 flows into the aeration decomposition chamber 10 after the sewage concentration is averaged. A swirl flow is generated by the air from the air diffuser 12, the organic components are decomposed by aerobic bacteria, and the scum and the like that have settled and accumulated are returned to the anaerobic filter bed first chamber 1.

On the other hand, the supernatant passes through the filter 17 and flows into the precipitation chamber 19 through the opening 14. At this time, scum and the like in the supernatant liquid are captured by the filter 17 in the aeration decomposition chamber 10. That is, the wastewater treated in the aeration decomposition chamber 10 cannot be admitted to the clarification chamber 19 and the disinfection chamber 21 unless it passes through the filter 17. Therefore, even if a large amount of dirty water flows in in a short time, scum in the aeration decomposition chamber 10 can be captured by the filter 17.

Further, in the case where a fine scum which has penetrated through the eyes of the filter 17 or the like, a scum which has passed through during the replacement of the filter 17, or a large amount of dirty water has flowed in in a short time, the inside of the sedimentation chamber 19 For the scum that came up in,
It is captured by the scum skimmer 22 and returned to the anaerobic filter bed first chamber 1 in cooperation with the air lift pump 25.

Thus, in the case of the invention according to claim 1,
The removal equipment for scum and the like has a two-stage structure consisting of a filter 17, a scum skimmer 22 and an air lift pump 25, so that scum and the like is reliably removed and becomes wastewater from the sedimentation chamber 19 through the overflow weir 20. Then, it is admitted to the disinfection chamber 21, and after being sterilized by the disinfectant, it is sequentially discharged from the drainage port 30.

In the above-mentioned example according to the invention described in claim 1, the filter is made of a non-woven fabric made of polyethylene fiber, but the present invention is not limited to this, and it is made of various other natural fibers and synthetic fibers. A fibrous plate-like structure such as a woven cloth, a net cloth, or a non-woven cloth is used. Further, as one of the methods for obtaining a more effective filter, there is a method of sequentially laminating plate-like structural bodies having fine meshes toward the downstream side.

Other specific examples of the material of the filter include synthetic resins such as polyethylene, polypropylene, urethane and polyvinyl chloride, natural rubber, chloroprene, silicon, butadiene acrylonitrile rubber (NBR) and ethylene propylene rubber (EPR). An open-cell foam having a plate shape made of synthetic rubber can be used. In short, the material is not particularly limited as long as it has water passage holes of about 0.1 to 5 mm or less through which the liquid is passed and filtered.

Regarding the size of the opening, the type of filter, the size of the filter eye, etc., the water level rises abnormally due to the inflow of water during the morning when the amount of water used is the largest, and the treatment in the next treatment chamber is performed. In order to prevent short-circuiting in the process and advection of untreated water, it is preferable to individually test each sewage treatment apparatus and design or select the optimal one for use.

As one guideline for selecting a filter, a normal daily average inflow sewage amount is obtained, and even if 6 to 10 times the average inflow sewage flow continuously for about 10 minutes, a short circuit will occur. Sufficient safety will be maintained if a material that does not occur is selected.

FIG. 4 is a vertical cross-sectional view showing the entire structure of an example of the wastewater treatment apparatus of the second aspect of the invention.
The same parts as those of the sewage treatment apparatus according to the first aspect of the present invention will be designated by the same reference numerals, and overlapping description will be omitted.

Reference numeral 31 is a partition wall, 32 is a first clarification chamber, and 33 is a second clarification chamber. The partition wall 31 divides the aeration decomposition chamber 10 and the first clarification chamber 32. The lower end edge of is separated from the bottom wall of the tank to form a gap 34. A return port 35 is provided 2 cm below the water surface of the partition wall 31, and a return plate 36 is provided so as to project along the return port 35.

The air diffuser 12 is incorporated near the lower end of the partition wall 31 on the side of the aeration decomposition chamber 10 and forms an upward flow of sewage due to the ejection of fine bubbles. This rising water flow hits the return plate 36 near the water surface and flows in the direction opposite to the advection direction, and forms a counterclockwise swirling flow as a whole. At this time, the scum on the water surface of the first sedimentation chamber 32 is returned to the aeration decomposition chamber 10 through the return port 35.

Further, although the pumping pipe 29 of the air lift pump for returning the settled / accumulated scum in the aeration decomposition chamber 10 is provided, its function is almost the same as the example of the invention described in claim 1. The detailed description will be omitted.

Further, a rectifying plate 37 is provided at the lower end of the partition wall 31, and the swirling flow of the aeration decomposition chamber 10 causes the first precipitation chamber 32 to flow.
Aeration decomposition chamber 10 by attracting scum accumulated on the bottom of
It is supposed to be returned to the side. Reference numeral 38 is a shield plate for preventing the swirling flow of the aeration decomposition chamber 10 from flowing back to the second advection port 8.

Reference numeral 39 is a partition wall for partitioning the first clarification chamber 32 and the second clarification chamber 33. In the middle thereof, at a depth of about ½ of the water depth, the first clarification chamber is directed upward. About 4 on the room 32 side
An inclined surface 40 having a height of about 25 cm inclined by 5 ° is formed,
The inclined surface 40 is provided with an opening 41 having a height of 20 and a width of 50 cm.

FIG. 5 shows a scum skimmer and an air lift pump,
FIG. 6 is a perspective view for explaining the arrangement state of the opening 41 and the filter and the operation thereof.

A filter 42 made of polyethylene fiber non-woven fabric is attached to the opening 41 on the first clarification chamber 32 side with screws. In addition, this filter 4
It is optional that the item 2 can be inserted and removed as in the example according to the first aspect of the invention.

Advection from the first clarification chamber 32 to the second clarification chamber 33 is possible by this opening 41. Reference numeral 43 is a backwash pipe that is activated when the filter 41 is clogged.
The functions of the scum skimmer 22 and the air lift pump 25 and the like are almost the same as those of the example of the invention described in claim 1, and therefore detailed description thereof will be omitted.

The main operation of the sewage treatment apparatus according to the second aspect of the present invention will be summarized below. The anaerobic filter bed first chamber 1
The sewage treated in the anaerobic filter bed second chamber 5 flows into the aeration decomposition chamber 10 after the sewage concentration is averaged. A counterclockwise swirling flow is generated by the air from the air diffuser 12 and the organic components are decomposed by aerobic bacteria, and the settled / accumulated scum and the like are returned to the anaerobic filter bed first chamber 1 by the pumping pipe 29. To be done.

On the other hand, the sewage enters the first clarification chamber 32 through the gap 34, further passes through the filter 42 and the opening 41.
Then, the second sedimentation chamber 33 is entered. At this time, scum or the like in the supernatant is captured by the filter 42. That is, the sewage treated in the aeration decomposition chamber 10 cannot be transferred to the second clarification chamber 32 and the disinfection chamber 21 unless it passes through the opening 41 through the filter 42. Therefore, even if a large amount of dirty water flows in in a short time, scum in the aeration decomposition chamber 10 can be captured by the filter 42.

The scum skimmer 22 captures scum that has penetrated through the eyes of the filter 42, or scum that has risen in the second sedimentation chamber 33 when a large amount of dirty water has flowed in in a short time. Then, it is returned to the anaerobic filter bed first chamber 1 in cooperation with the air lift pump 25.

Since the filter 42 is located deep and is of a fixed type, if it is clogged,
It suffices to operate the backwash pipe 43 to wash it off, and scum and the like separated from the filter 42 during the operation are removed from the second clarification chamber 3
Since it does not flow into No. 3, the function of the sewage treatment apparatus does not deteriorate.

As described above, as in the case of the first aspect of the present invention, the scum removing device has a two-stage structure including the filter 42, the scum skimmer 22 and the air lift pump 25. The sewage that has been reliably removed is transferred from the second sedimentation chamber 33 to the disinfection chamber 21 via the overflow weir 20, and after being sterilized by the disinfectant, the drainage port 3
It is released successively from 0.

The material and structure of the filter, the relationship with the size of the opening, the standard of selection, etc. are the same as in the case of the above-mentioned invention of claim 1, and therefore will be omitted.

[0054]

The sewage treatment apparatus of the present invention has only the opening provided in the partition wall for partitioning each of the aeration decomposition chamber and the sedimentation chamber or the first sedimentation chamber to the second sedimentation chamber when advancing. Since a filter is attached to this opening, there is a sudden increase in the aeration decomposition chamber and the first sedimentation chamber, especially in the morning hours when a large amount of dirty water flows in in a short time. Even if the water quality deteriorates, the outflow of scum or the like to the disinfection chamber can be effectively captured by the filter, so that the deterioration of the water quality of the wastewater can be prevented.

As a measure against clogging of the filter,
In the case of the invention described in claim 1, since the filter can be fitted and removed, replacement can be smoothly and promptly performed, and the function as a septic tank can be maintained as it is at the time of replacement without being substantially deteriorated. In the case of the second aspect of the invention, the washing operation can be easily performed by installing the backwash pipe, and no special operation or the like is required to prevent outflow of scum after the backwash.

Furthermore, in consideration of scum and the like invading or floating in the first clarification chamber and the second clarification chamber when the filter is replaced or backwashed, the scum skimmer and the air lift pump should be taken into consideration. Since the following trapping device is attached and the trapping means such as scum is provided in two stages, the water quality can be improved more reliably and the wastewater treatment device can be discharged with peace of mind.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the entire structure of an example of a sewage treatment apparatus according to the first aspect of the invention.

FIG. 2 (a) is a partially cutaway perspective view showing an opening and a mounting state of a filter with respect to the opening in the same apparatus, and FIG. 2 (b) is a perspective view showing only the filter. FIG. 3C is a perspective view for explaining the disposition state of the scum skimmer and the air lift pump and the operation thereof.

FIG. 3 is a plan view of only a main part showing the inside of the sewage treatment apparatus shown in FIG. 1 with an inspection lid removed.

FIG. 4 is a vertical cross-sectional view showing the entire structure of an example of the sewage treatment apparatus according to the second aspect of the invention.

FIG. 5 is a perspective view for explaining a disposition state of a scum skimmer and an air lift pump, an opening portion and a filter, and an operation thereof in the above.

[Explanation of symbols]

 1 Anaerobic filter bed 1st chamber 5 Anaerobic filter bed 2nd chamber 9 Sewage intake 10 Aeration decomposition chamber 11 Contact material 13, 31, 39 Partition wall 14, 41 Opening 15 Holding frame 16 Fitting groove 17, 42 Filter 19 Sedimentation Room 21 Disinfection room 22 Scum skimmer 23 Scoop 24 Suction pipe 25 Air lift pump 26, 29 Pumping pipe 27 Air pressure feeding pipe 30 Drain 32 First clarification chamber 33 Second clarification chamber 34 Gap 40 Slope 42 Backwash pipe

Claims (2)

[Claims] 1. In a sewage treatment apparatus having at least an aeration decomposition chamber, a clarification chamber and a disinfection chamber in the advection direction, advection from the aeration decomposition chamber to the clarification chamber is provided near the water surface of a partition wall separating both chambers. It is made possible by the opened opening, a filter is removably mounted on the side of the aeration decomposition chamber of this opening, and a scum skimmer and an air lift pump linked with this are attached on the side of the sedimentation chamber. Sewage treatment equipment to be. 2. A sewage treatment apparatus comprising at least an aeration decomposition chamber, a clarification chamber and a disinfection chamber in the advection direction, wherein the clarification chamber is divided by a partition wall toward the advection direction and the first clarification chamber and the second clarification chamber are provided. It is divided into chambers, and an inclined surface is formed in the middle of the partition wall so as to incline upward toward the first sedimentation chamber and an opening is provided in this inclined surface. Advection to the chamber is enabled by this opening, a filter is attached to the first clarification chamber side of the opening, and a scum skimmer and an air lift pump linked with this are attached to the second clarification chamber side. A sewage treatment device characterized by the above.