JPH06165901A - Sewage treatment device - Google Patents

Abstract

PURPOSE:To provide a sewage treatment device which can efficiently settle and separate the solids in sewage. CONSTITUTION:An inside cylinder 11 is vertically provided in a treatment tank 10 by parting the bottom end of the cylinder from the bottom of the tank to form an endless water path. The front end of a water feed pipe 13 plunged into the water of the endless water path is provided with two branch ejection ports 14a, 14b which supply raw water to the endless water path in diametrically opposite direction to whirl the water. A baffle plate 16 which crosses the endless water path is oscillatably hung down in the position diametrically opposite from the position within the endless water path where the water feed pipe is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus suitable for pretreatment of organic domestic wastewater, industrial wastewater, etc., in which the amount and quality of intermittently discharged wastewater change in a short time.

[0002]

2. Description of the Related Art One of the applicants of this patent, Yamato Equipment Co., Ltd., discloses that a lower end of a processing tank is separated from a bottom of the processing tank and an upper end thereof is projected above the water surface according to Japanese Patent Laid-Open No. 63-158191. An inner cylinder is installed vertically to form an endless water channel between the inner circumference of the treatment tank and the outer circumference of the inner cylinder, and raw water is supplied to the endless water channel by a water supply pipe to treat the treated water from the inside of the inner cylinder. We proposed a sewage treatment device that drains out of the tank with a drainage pipe. This sewage treatment apparatus is a solid-liquid settling / separating apparatus, and is provided with a lateral jet outlet at the tip of a water supply pipe that rushes into the water of an endless water channel to turn raw water into a unidirectional swirling flow along the endless water channel. , Coarse solids in raw water are fine SS on the bottom of the endless water channel.
Is allowed to settle on the bottom of the tank below the inner cylinder.

[0003]

According to the above-mentioned prior proposal, the swirling flow of the raw water ejected from the lateral ejection port at the tip of the water supply pipe into the endless channel reduces kinetic energy only by gravity and friction between the channel wall surface. Therefore, the inside of the tank is disturbed by the swirling flow, and it takes time for the liquid in the tank to stand still, during which the solid matter deposited on the bottom of the tank is lifted up or the solid matter is settled uniformly on the bottom of the tank. Can't do enough. Furthermore, in order to perform biological treatment in order to obtain high treated water quality, the treated water extracted from the inner cylinder to the outside of the treatment tank must be introduced to a separately installed biological treatment tank for treatment, and the installation space However, problems such as cost increase occur.

[0004]

According to a first aspect of the present invention, there is provided a sewage treatment apparatus as a sedimentation separation apparatus in which the kinetic energy of a swirling flow is rapidly reduced to solve the above-mentioned problems. An inner cylinder with the lower end separated from the tank bottom and the upper end protruding above the water surface is vertically installed to form an endless water channel between the inner circumference of the treatment tank and the outer circumference of the inner cylinder. In the wastewater treatment device in which the treated water is supplied from the inside of the inner cylinder to the outside of the treatment tank by the drainage pipe, the raw water is supplied to the end of the water supply pipe protruding into the water of the endless water channel. Two branch jets are provided in the water channel to supply and rotate in opposite directions, and a baffle plate that traverses the endless water channel is provided at a position in the endless water channel which is exactly opposite to the position where the water supply pipe is provided. Is characterized by. Further, claim 2 relates to a sewage treatment apparatus in which settling separation and anaerobic biological treatment are performed in one tank, wherein the lower end is separated from the tank bottom and the upper end is above the water surface inside the treatment tank. An inner cylinder protruding vertically is formed to form an endless water channel between the inner circumference of the treatment tank and the outer circumference of the inner cylinder.
In a sewage treatment apparatus in which raw water is supplied to the endless water channel by a water supply pipe, and treated water is drawn out of a treatment tank from the inside of an inner cylinder by a drain pipe, the tip of the water supply pipe protruding into the water of the endless water channel. Is provided with two branch spouts for supplying raw water to the endless water channel in opposite directions to swirl the same, and an obstacle that crosses the endless water channel at a position in the endless water channel opposite to the position where the water supply pipe is provided. It is characterized in that a plate is provided, the carrier group to which microorganisms are adhered is densely supported inside the inner cylinder, and the carrier group is hung from the lower end of the inner cylinder. In the sewage treatment apparatus according to any one of claims 1 and 2, the baffle plate provided in the position opposite to the water supply pipe in the endless water channel is swingably suspended across the endless water channel. It is preferable.

[0005]

1 and 2 show an embodiment of a sewage treatment apparatus according to claim 1, and FIGS. 3 and 4 show an embodiment of a sewage treatment apparatus according to claim 2. In each of these examples, 10 is a processing tank having a bottom,
Reference numeral 11 denotes an inner cylinder that is vertically installed inside the processing tank, has its lower end separated from the tank bottom 10 ′ and has its upper end protruding above the water surface, and is located between the inner circumference of the processing tank 10 and the outer circumference of the inner cylinder 11. There are 12 endless waterways
Are formed. Reference numeral 13 is a water supply pipe for supplying raw water (dirty water) into the endless water channel 12, 15 is a drain pipe for extracting treated water from the inside of the inner cylinder 11 to the outside of the treatment tank 10, and the treated water in the inner cylinder is a drain pipe. Overflows and flows into the inner cylinder 1
The water level L inside 1 and in the endless water channel 12 is kept constant. The lower end of the inner cylinder 11 has a water level of about 40 degrees from the tank bottom 10 '.
Located at ~ 50%.

In the illustrated embodiment, the treatment tank 10 and the inner cylinder 11 are cylindrical, and are arranged concentrically, so that the endless water channel 12 is annular, but the treatment tank and / or the inner cylinder is a polygonal cylinder. The shape of the inner cylinder with respect to the treatment tank may not be concentric as long as the closed endless water channel 12 is formed. Further, the diameter and depth of the treatment tank 10 and the diameter and length of the inner cylinder 11 are appropriately determined according to the discharge amount of sewage to be treated, stagnant time and the like.

A water supply pipe 13 protruding into the water of the endless water channel 12
Has a T-shaped tip and has two branch jets 14a,
14b. Both spouts 14a and 14b are the inner cylinder 1
1, the raw water intermittently supplied by the water supply pipe 13 is tangentially opposite to
It is roughly divided into two by 14b, and jets in opposite directions from the respective branch jets 14a, 14b into the endless water channel 12 to generate two swirling flows A, B in opposite directions (Fig. 2,
4, 5).

A position in the endless water channel 12 which is opposite to the position where the water supply pipe 13 is provided, in this embodiment, the treatment tank 10,
Since the inner cylinder 11 is cylindrical, a baffle plate 16 that crosses the endless water channel 12 is provided at a position diametrically opposed to the position of the water supply pipe 13. The upper end of the baffle plate 16 projects upward from the water level L in the endless water channel 12.

As described above, the raw water intermittently supplied through the water supply pipe 13 is roughly bisected by the two opposite branch jets 14a and 14b provided at the lower end of the pipe 13, and each branch jet 14a, Two swirling flows A and B in opposite directions are generated in the endless water channel by ejecting from 14b in opposite directions. As shown in FIG. 5, the swirling flows A and B collide with the respective surfaces of the baffle plate 16 that traverses the endless water channel 12 at a position opposite to the water supply pipe 13, and the reversing flows A ′ and B return by the collision. become. Since the baffle plate 16 is for changing the swirling flows A and B into the reverse flows A ′ and B ′ in the opposite directions, the position of the lower end 16 ′ or the downward length of the baffle plate is endless. The swirling flows A and B, which spread downward in the waterway, are determined so that they can collide reliably.

In the sewage treatment apparatus according to the present invention, the two branch jets 14a, 14b provided at the tip of the water supply pipe 13 roughly divide the sewage supplied into the endless water channel 12 into the water channel in opposite directions. Two swirl flows A and B are generated. The kinetic energy of each of the divided swirling flows A and B is smaller than the kinetic energy of one undivided swirling flow. Therefore, the kinetic energy of the two swirling flows A and B is largely reduced by the friction with the wall surface of the endless water channel.

The two swirling flows A and B collide with the baffle plate 16 while reducing the kinetic energy, and the reverse flow A
The kinetic energy is greatly reduced by the collision with the baffle plate, and the kinetic energy of the reversal flows A'and B'is greatly attenuated. As a result, sewage is intermittently supplied to the endless water channel 12, and two swirling flows and reverse flows are generated in the endless water channel, but the liquid in the water channel is quickly left to stand and solid matter deposited on the tank bottom ( Re-floating of sedimented sludge) does not occur. Then, due to the two swirling flows and the reversing flow, the solid matter having a large mass in the wastewater is discharged from the bottom 1 of the tank 1 below the endless water channel 12.
It uniformly deposits at 0'and does not accumulate.

The baffle plate 16 for changing the swirling flows A and B into the reverse flows A'and B'in the opposite directions in the endless water channel 12,
It may be fixedly provided at a position opposite to the water supply pipe 13, but it is preferable to be provided so as to be swingable like a pendulum in the water of the endless water channel for the reason described later. In the illustrated embodiments, since the drain pipe 15 also serves to suspend the baffle plate, the drain pipe 15 is traversed to the position where the baffle plate 16 is suspended on the endless water channel, and the support 17 attached to the upper end of the baffle plate 17 is provided. Is fitted to the drain pipe to suspend the baffle so that it can swing, but not limited to this, the horizontal axis other than the drain pipe is fixed across the endless water channel,
The baffle plate may be oscillatedly hung on this, or the baffle plate may be oscillatedly hung by a hinge on a support fixed transversely on the endless water channel.

As described above, the two branch jets 14a and 14b at the tip of the water supply pipe 13 roughly divide the sewage into the endless water channel 12 and supply it to the water channel. , B, but with the branch jets 14a, 14
Since there is a difference in the flow rate of the sewage flowing out of b, the two swirling flows A and B are asymmetrical non-uniform flows. This tendency is that a large amount of sewage, such as drainage from a bathtub, is temporarily discharged from the water supply pipe 13 to the endless water channel 1.
It appears remarkably when flowing into 2. Then, the reversal flows A ′ and B ′ after the asymmetrical non-uniform swirling flows A and B collide with the baffle plate 16 do not become symmetrical reversal flows when the baffle plate is fixed, and the momentum In order to maintain the balance of the above, a downward flow to the bottom of the tank is generated and the flow in the tank is disturbed. However, if the baffle plate 16 is swingably suspended as described above, the baffle plate 16 is swung up to an angle that balances the momentum of the asymmetrical non-uniform swirling flows A and B. Reverse flow A
′ And B ′ are almost completely symmetrical flows to maintain the balance of momentum, the downward flow to the bottom of the tank is suppressed, the damping effect of the flow in the tank is enhanced, and no disturbance occurs.

As a result of the above, sewage is intermittently supplied to the endless water channel 12 to generate two swirling flows and a reverse flow, but the liquid in the water channel is quickly allowed to stand still, and solid matter deposited on the bottom of the tank (accumulation) Re-emergence of sludge) does not occur. Then, due to the two swirling flows and the reversing flow, the solid matter having a large mass in the wastewater is uniformly deposited on the tank bottom 10 ′ below the endless water channel 12 and is not accumulated. Then, in the case of the wastewater treatment device of FIGS. 1 and 2, as the supernatant treated water near the water surface inside the inner cylinder 11 overflows into the drain pipe 15 and is drawn out, the liquid outside the inner cylinder is The SS that enters the inside of the cylinder from below and is suspended in the liquid is settled and deposited on the tank bottom 10 'below the inner cylinder in the form of a sludge blanket.

In the case of the sewage treatment apparatus of the embodiments shown in FIGS. 3 and 4, a large number of carriers 18 to which microorganisms such as anaerobic bacteria and aerobic bacteria are adhered are densely supported inside the cylindrical body 11, It hangs from the lower end of the inner cylinder to the bottom of the processing tank, or to an intermediate position between the bottom and the lower end of the inner cylinder. The carrier 18 may be a non-woven fabric that is lightweight and flexible and has good bacterial cell adhesion, or may be a solid material made of plastic or the like having good bacterial cell adhesion. Wire mesh-like support plates 19 are attached to the upper and lower ends of the densely packed carriers 18, the support plates with the upper ends are fixed inside the inner cylinder 11, and the carriers are vertically tensioned with the support plates attached to the lower ends. And, it is preferred to prevent the carriers from moving individually in a water stream.

In this sewage treatment apparatus also, as described above, two swirling flows and a reverse flow are generated in the water channel due to the sewage intermittently supplied to the endless water channel 12, but the liquid in the water channel is promptly left to stand still. , Re-floatation of solid matter (sludge sludge) deposited on the bottom of the tank and soaring does not occur. Then, due to the two swirling flows and the reversing flow, the solid matter having a large mass in the wastewater is converted into the endless water channel 1.
2 is uniformly deposited on the bottom 10 ′ of the tank 2 and does not accumulate. Then, as the supernatant-treated water near the water surface inside the inner cylinder 11 overflows into the drain pipe 15 and is drawn out, the liquid outside the inner cylinder falls from the lower end of the inner cylinder to the dense carrier 18 As it enters the inside of the inner cylinder from below through the space and rises to the water surface, and its rising speed is reduced by the flow resistance of the carrier 18, it suppresses the sweeping of fine solids with a small mass and the liquid. B of the treated water which is brought into contact with the microorganisms adhering to the carrier at that time and biologically treats the BOD component in the liquid, and is discharged from the drain pipe 15
The OD concentration decreases.

Further, since the sedimentation and separation of the solid matter in the endless water channel 12 is efficiently performed, the overloaded state of the solid matter with respect to the microorganisms adhering to the carrier 18 is prevented, and the biological treatment by the microorganisms is also efficient. To be done.

Further, when the microorganisms attached to the carrier 18 grow, they partly separate from the carrier and settle on the bottom 10 'of the tank, and biologically treat the solid sludge accumulated on the bottom of the tank.

A conventional settling tank (hereinafter referred to as a conventional apparatus),
Figure 3 shows the results of a comparative experiment in which the combined sewage (miscellaneous drainage and flush toilet drainage) of household A was treated in the same period from March to August using the sewage treatment equipment (referred to as implementation equipment) shown in Figs. 6
Shown in. For the same tank capacity, B
The OD concentration decreased to almost half of the BOD concentration of the treated water of the conventional apparatus, demonstrating that the treatment capacity of the embodying apparatus was extremely high. Further, the fluctuation range of the BOD concentration of the treated water is extremely small in the embodying apparatus as compared with the conventional apparatus. In Figure 7,
The SS concentration of treated water is shown for the above comparative experiment example. S
Similarly to the BOD concentration, the S concentration has a significantly higher processing capacity of the embodying apparatus than that of the conventional apparatus.

FIG. 8 shows a conventional type anaerobic filter bed tank (referred to as a conventional device) and a sewage treatment device (implementing device) shown in FIGS. The result of the comparative experiment which treated combined domestic wastewater is shown. The BOD of the treated water treated by the embodying device is extremely stable as compared with the conventional device. Further, in the conventional apparatus, the anaerobic filter bed has a two-chamber structure, whereas the apparatus for carrying out the present invention has a single tank, so the tank capacity is small, and therefore no space is required for installation. The SS concentration of treated water in this comparative experiment is shown in FIG. The SS concentration of the implementing device is
In addition to being lower than conventional devices, the fluctuation range of SS concentration is extremely small. In particular, after 100 days have passed, the SS concentration of the conventional apparatus tends to increase, and since the second chamber is higher than the first chamber, clogging occurs in the first chamber. Contrary to what you can see, SS at the implementing device
The concentration is extremely stable.

When a large amount of drainage from the bath tub flows in at one time, the sewage treatment apparatus shown in FIGS.
Table 1 shows the BOD concentration and the SS concentration of the treated water from the conventional settling device and the conventional anaerobic filter bed tank. The value of the practitioner was significantly lower than that of either of the two conventional devices, demonstrating the high throughput of the practitioner.

[Table 1]

[0022]

According to the sewage treatment apparatus of the first aspect, sedimentation and separation of solid matter in sewage can be performed very efficiently. Therefore, by using this sewage treatment device in a relatively small scale such as homes, offices, hotels, public halls, etc. in the front stage of a purification facility for organic sewage that is discharged unsteady, The solid load and the load of SS can be greatly reduced, contributing to the improvement of the quality of the final treated water.

The sewage treatment apparatus according to the second aspect enables efficient sedimentation and separation and biological treatment with microorganisms in a single treatment tank. Therefore, by using this sewage treatment equipment in a relatively small scale such as homes, offices, hotels, public halls, etc. in front of a purification facility for organic sewage discharged unsteadily, It can significantly reduce the load of solid matter and SS, improve the treatment performance such as denitrification and dephosphorization, and significantly contribute to the improvement of the water quality of the final treated water.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of the sewage treatment apparatus according to claim 1.

FIG. 2 is a plan view of FIG.

FIG. 3 is a vertical cross-sectional view of an embodiment of the sewage treatment apparatus according to claim 2.

FIG. 4 is a plan view of FIG.

FIG. 5 is a schematic diagram showing a sedimentation separation action of the wastewater treatment device of FIGS. 1 and 3.

FIG. 6 is a comparative chart showing the BOD concentration of treated water treated by the conventional sedimentation separation tank and the sewage treatment apparatus of the present invention.

FIG. 7 is a comparative chart showing the SS concentration of treated water treated by the conventional sedimentation separation tank and the sewage treatment apparatus of the present invention.

FIG. 8 is a comparative chart showing the BOD concentration of treated water treated by the conventional two-bed type anaerobic filter bed tank and the sewage treatment apparatus of the present invention.

FIG. 9 is a comparative chart showing SS concentrations of treated water treated by the conventional two-bed type anaerobic filter bed tank and the sewage treatment apparatus of the present invention.

[Explanation of symbols]

 10 treatment tank 10 'tank bottom 11 inner cylinder 12 endless water channel 13 water supply pipe 14a branch jet 14b branch jet 15 drain pipe 16 baffle plate 17 support 18 microorganism carrier 19 support plate A swirling flow B swirling flow A' inversion Flow B'reverse flow

Claims (3)

[Claims] 1. An inner cylinder having a lower end separated from the tank bottom and an upper end projecting above the water surface is vertically installed inside the treatment tank to provide an endless structure between the inner circumference of the treatment tank and the outer circumference of the inner cylinder. In a sewage treatment apparatus that forms a water channel, supplies raw water into the endless water channel with a water supply pipe, and drains the treated water from the inside of the inner cylinder to the outside of the treatment tank with a drain pipe. At the tip of the water supply pipe, two branch jets for supplying raw water to the endless water channel in the opposite directions to swirl are provided, and at the position in the endless water channel opposite to the position where the water supply pipe is provided. A sewage treatment apparatus comprising a baffle plate that traverses the endless water channel. 2. An inner cylinder having a lower end separated from the tank bottom and an upper end projecting above the water surface is vertically installed inside the treatment tank to provide an endless structure between the inner circumference of the treatment tank and the outer circumference of the inner cylinder. In a sewage treatment apparatus that forms a water channel, supplies raw water into the endless water channel with a water supply pipe, and drains the treated water from the inside of the inner cylinder to the outside of the treatment tank with a drain pipe. At the tip of the water supply pipe, two branch jets for supplying raw water to the endless water channel in the opposite directions to swirl are provided, and in the endless water channel, a position opposite to the position where the water supply pipe is provided is provided. A sewage treatment characterized by providing a baffle that traverses an endless water channel, densely supporting a carrier group to which microorganisms are attached inside an inner cylinder, and suspending the carrier group from the lower end of the inner cylinder. apparatus. 3. The sewage treatment apparatus according to claim 1, wherein the baffle plate provided in the endless water channel at a position directly opposite to the water supply pipe serves to connect the endless water channel. A sewage treatment device characterized in that it is swingably suspended across.