JP2021186730A - Water treatment device, water treatment system and water treatment method - Google Patents

Abstract

To provide a low-cost water treatment device that can stably suppress a generation of hydrogen sulfide during a normal operation.SOLUTION: There is provided a water treatment device that dissolves oxygen-containing gas in a sewage supplied to a drain tank and discharges it as high-concentration oxygen-containing water from a discharge pipe, including: a mixing device that mixes oxygen-containing gas with sewage to make a fine bubble-containing liquid; a liquid supply device that supplies the sewage to the mixing device and the discharge pipe via a drain pipe; and a gas supply device that supplies the oxygen-containing gas to the mixing device, in which an arrangement of the mixing device satisfies the following arrangement 1 or arrangement 2. Arrangement 1: the mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as the high-concentration oxygen-containing water. Arrangement 2: the mixing device is arranged in a return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water treatment apparatus, a water treatment system and a water treatment method.

A pumping type sewerage facility that pumps sewage using a pump or the like is known. In a pressure-feeding sewerage facility, if sewage stays in the sewage pressure-feeding pipe for a long time, the sewage becomes anaerobic and hydrogen sulfide is generated, which causes a foul odor. In addition, sulfuric acid caused by hydrogen sulfide causes corrosion of concrete and the like.

Various water treatment methods that suppress the generation of hydrogen sulfide have been proposed in order to prevent foul odors and corrosion. As a method of water treatment, a chemical addition treatment method (see Patent Documents 1 and 2) and a method of mixing air or oxygen with sewage (see Patent Documents 3 to 5) are known.

As a method for adding chemicals, for example, in Patent Document 1, a storage portion for a hydrogen sulfide remover is provided at the end of an ascending slope of a sewage pressure feed pipe so that the hydrogen sulfide remover can be supplied into the sewage pressure feed pipe via a pump. The method for removing hydrogen sulfide in the sewage pumping pipe is described.

Further, Patent Document 2 is a method for suppressing hydrogen sulfide in a manhole pump facility in which a chemical for suppressing the production of hydrogen sulfide is injected into sewage to suppress the production of hydrogen sulfide generated in the manhole pump facility. From the pH of sewage in the manhole pump facility, the sewage level, and the operation standby time of the manhole pump, the appropriate injection amount of chemicals for suppressing the production of hydrogen sulfide is obtained, and the appropriate injection amount of chemicals is injected into the sewage. A method for suppressing hydrogen sulfide in a manhole pump facility is described.

On the other hand, as a method of mixing air and oxygen with sewage, Patent Document 3 states that in a sewage pressure feed pipeline provided with a sewage pressure feed pump and an air injection pump, the air injection compressor and the sewage pressure feed pump are always operated in parallel. A method for controlling air injection in a sewage pressure feed pipeline is described in which the air injection compressor is independently driven only when the sewage pressure feed pump is not driven after a certain period of time has passed after the sewage pressure feed pump is stopped. ..

Patent Document 4 describes a water tank for storing sewage, a water level gauge for detecting the water level of sewage in the water tank, a pressure pump for pumping sewage in the water tank, and a pressure feed pump connected to the discharge side of the pressure feed pump and discharged from the pressure feed pump. A pressure feed pipe that discharges the sewage to the outside of the water tank, a return pipe that branches from the pressure feed pipe and opens into the water tank, an opening / closing mechanism that opens / closes the flow path of the return pipe, and a control that controls the pressure feeding pump and the opening / closing mechanism. It is a pumping type sewerage facility equipped with means, and the control means is a normal operation that starts the operation of the pumping pump when the water level of the water tank rises above the predetermined water level, and a part of the sewage in the pumping pipe by opening the opening / closing mechanism. Alternatively, a pumping type sewerage facility is described which performs a hydrogen sulfide suppression operation in which the opening / closing mechanism is closed after the whole is returned to the water tank through the return pipe, and then the operation of the pressure pump is started. Patent Document 4 also describes an embodiment provided with an oxygen supply means for supplying an oxygen-containing gas to sewage in a water tank before starting the operation of the pressure pump in the hydrogen sulfide suppression operation.

Further, Patent Document 5 describes a water treatment device for dissolving gas in sewage in a drainage tank, a mixing device having a storage chamber, a liquid supply device for pumping sewage and supplying it to the storage chamber, and a gas. It is equipped with a gas supply device that supplies gas to the storage chamber, a water quality measuring device that measures the water quality of sewage, and a control device that controls the liquid supply device and the gas supply device. A water treatment device is described in which a discharge port for discharging the treated water from the storage chamber to the drain tank is provided, and the control device drives the liquid supply device and the gas supply device according to the measured value of the water quality measuring device. Has been done.

Japanese Unexamined Patent Publication No. 2000-22291 Japanese Unexamined Patent Publication No. 2007-186887 Japanese Unexamined Patent Publication No. 11-172756 Patent No. 4195867 Japanese Unexamined Patent Publication No. 2019-85771

However, in the chemical addition treatment methods described in Patent Documents 1 and 2, it is difficult to control an appropriate addition amount, and the generation of hydrogen sulfide cannot be stably suppressed.

Among the methods of mixing air and oxygen with sewage, the method of injecting oxygen-containing gas into the sewage pressure feed pipe described in Patent Document 3 did not suggest improvement of the water treatment device provided with the drainage tank in the first place. Further, in the method described in Patent Document 3, gas may be mixed in the sewage pressure feed pipe and cause an increase in pressure loss, the smooth flow of sewage in the sewage pressure feed pipe is hindered, and the normal operation of the water treatment device is performed. It was a method that could be hindered.
The method described in Patent Document 4 is a method in which the oxygen dissolution efficiency is inferior because the oxygen-containing gas is directly supplied to the entire sewage in the drainage tank by stopping the normal operation, and the generation of hydrogen sulfide cannot be suppressed during the normal operation.
The method described in Patent Document 5 is a method using a liquid supply device different from the pump for draining sewage from the drainage tank, and requires a significant cost increase of the facility.

An object to be solved by the present invention is to provide a low-cost water treatment apparatus capable of stably suppressing the generation of hydrogen sulfide while operating normally.

As a result of diligent studies to solve the above problems, the present inventors mixed sewage with oxygen-containing gas by a mixing device arranged at a specific position to obtain a fine bubble-containing liquid, and the sewage was made into sewage. The above problem has been solved by configuring the liquid supply device that supplies the discharge pipe to also have the function of supplying sewage to the mixing device.
The configuration of the present invention, which is a specific means for solving the above problems, and the preferred configuration of the present invention are described below.

[1] A water treatment device for dissolving oxygen-containing gas in sewage supplied to a drainage tank and discharging it as high-concentration oxygen-containing water from a discharge pipe.
A mixing device that mixes oxygen-containing gas with sewage to make a fine bubble-containing liquid,
A liquid supply device that supplies sewage to the mixing device and discharge pipe via the drain pipe, and
Equipped with a gas supply device that supplies oxygen-containing gas to the mixing device,
A water treatment device in which the arrangement of the mixing device satisfies the following arrangement 1 or 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in the return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.
[2] The water treatment device according to [1], wherein the discharge pipe is filled with high-concentration oxygen-containing water and is connected to a sewage pressure feed pipe having an uphill slope.
[3] Equipped with multiple sets of liquid supply device and drainage pipe,
The water treatment device according to [1] or [2], wherein the mixing device is arranged at a position downstream of all the drain pipes.
[4] Satisfy placement 2 and
The water treatment apparatus according to any one of [1] to [3], wherein a return valve is provided between the drain pipe and the return flow path.
[5] The water treatment apparatus according to any one of [1] to [4], wherein the oxygen-containing gas is air outside the drainage tank.
[6] The water treatment apparatus according to any one of [1] to [5], wherein the fine bubble-containing liquid at the outlet of the mixing apparatus contains an oxygen-containing gas having a bubble diameter of 500 nm or less.
[7] The mixing device includes a processing tank having a storage chamber in which the fine bubble-containing liquid is stored.
On the inside of the storage room,
In addition to opening the inlet of the inlet for injecting sewage and oxygen-containing gas into the storage chamber,
The discharge port of the discharge path for discharging the fine bubble-containing liquid from the storage chamber is open.
The inlet is located on the first inner surface of the storage chamber
The water treatment device according to any one of [1] to [6], wherein the discharge port is arranged on an inner surface other than the second inner surface facing the first inner surface of the storage chamber.
[8] The water treatment apparatus according to any one of [1] to [7], wherein the drainage tank is a manhole pumping station.
[9] Further, the liquid quality of the sewage measured by the liquid quality measuring instrument in the water treatment apparatus provided with at least one of the liquid quality measuring instrument and the hydrogen sulfide concentration sensor and the control device, and the sulfide measured by the hydrogen sulfide concentration sensor. The water treatment device according to any one of [1] to [8], wherein the control device controls the liquid supply device and the gas supply device according to at least one of the hydrogen concentrations.
[10] A water treatment system including a plurality of water treatment devices according to any one of [1] to [9].
[11] The water treatment device further includes at least one of a liquid quality measuring device and a hydrogen sulfide concentration sensor, and a control device.
The control device of the upstream water treatment device is the liquid supply device according to at least one of the liquid quality of the sewage measured by the liquid quality measuring device in the downstream water treatment device and the hydrogen sulfide concentration measured by the hydrogen sulfide concentration sensor. The water treatment system according to [10], wherein the gas supply device is feedback-controlled.
[12] A water treatment method for dissolving oxygen-containing gas in sewage supplied to a drainage tank and discharging it as high-concentration oxygen-containing water from a discharge pipe.
In the mixing device, the mixing step of mixing oxygen-containing gas with sewage to obtain a fine bubble-containing liquid,
A liquid supply process that supplies sewage to the mixing device and discharge pipe via the drain pipe,
It is equipped with a gas supply process that supplies oxygen-containing gas to the mixing device.
A water treatment method in which the arrangement of the mixing device satisfies the following arrangement 1 or 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in the return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.
[13] The water treatment method according to [12], which is a method for suppressing the generation of hydrogen sulfide.

According to the present invention, it is possible to stably suppress the generation of hydrogen sulfide while operating normally, and to provide a low-cost water treatment apparatus.

FIG. 1 is a schematic view of an example of the water treatment apparatus of the present invention. FIG. 2 is a schematic view of an example of a mixing device used in a water treatment device. FIG. 3 is a schematic view of another example of the water treatment apparatus of the present invention. FIG. 4 is a schematic view of another example of the water treatment apparatus of the present invention. FIG. 5 is a schematic view of another example of the water treatment apparatus of the present invention. FIG. 6 is a schematic view of an example of a water treatment system using the water treatment apparatus of the present invention.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

[Water treatment device]
The water treatment device of the present invention is a water treatment device for dissolving an oxygen-containing gas in sewage supplied to a drainage tank and discharging it as high-concentration oxygen-containing water from a discharge pipe, and the oxygen-containing gas is mixed with the sewage. A mixing device including a mixing device for producing a fine bubble-containing liquid, a liquid supply device for supplying sewage to the mixing device and the discharge pipe via a drain pipe, and a gas supply device for supplying an oxygen-containing gas to the mixing device. Arrangement of is satisfied with the following arrangement 1 or arrangement 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in the return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.
According to the water treatment apparatus of the present invention, the generation of hydrogen sulfide can be stably suppressed during normal operation, and the cost is low. Since oxygen-containing gas is mixed with sewage by a mixing device arranged at a specific position to form a fine bubble-containing liquid, oxygen dissolution efficiency is higher than when oxygen-containing gas with a large bubble diameter is applied to the entire sewage in the drainage tank. Can be raised. As a result, anaerobic sewage in the drainage tank can be prevented, and the generation of hydrogen sulfide can be stably suppressed during normal operation. Further, since the liquid supply device that supplies sewage to the discharge pipe also has a function of supplying sewage to the mixing device, it is not necessary to newly install a submersible pump, and the water treatment device can be made at low cost. Since this configuration can save space, the water treatment apparatus of the present invention can be used even when space is restricted such as in a small manhole pumping station.
Further, according to a preferred embodiment of the present invention, when the sewage in an aerobic state is sent from the discharge pipe of the water treatment device to the sewage pressure feed pipe, anaerobicization in the sewage pressure feed pipe which is a closed space is suppressed. It is also possible to suppress the generation of hydrogen sulfide at the outlet of the sewage pressure feed pipe.
Further, according to a preferred embodiment of the water treatment apparatus of the present invention, since fine bubbles can be applied, the required supply amount of oxygen-containing gas can be suppressed.
According to a preferred embodiment of the water treatment apparatus of the present invention, since it is not necessary to supply a large amount of oxygen-containing gas, it is possible to suppress the problem that the flow rate of the drainage pump decreases due to the pressure loss due to the increase in the internal pressure of the discharge pipe.
When the water treatment apparatus of the present invention is used, it is not necessary to renew the manhole due to corrosion, so that it is not necessary to perform replacement work when renewing the manhole to a manhole having a lining method, and to block the road for a long time.
Hereinafter, preferred embodiments of the water treatment apparatus of the present invention will be described.

<Overall configuration of water treatment equipment>
A preferred embodiment of the overall configuration of the water treatment apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an example of the water treatment apparatus of the present invention, and is an example in which the arrangement of the mixing apparatus satisfies the arrangement 1.
The water treatment device 1 shown in FIG. 1 is a water treatment device 1 for dissolving oxygen-containing gas 31 in sewage 21 supplied to the drainage tank 2 and discharging it as high-concentration oxygen-containing water 22 from a discharge pipe.
In the water treatment device shown in FIG. 1, the sewage 21 flows in from the inflow passage 2a provided at an arbitrary position of the drainage tank 2 and is stored in the bottom of the drainage tank 2.
The water treatment device 1 shown in FIG. 1 includes a mixing device 11 that mixes an oxygen-containing gas 31 with a sewage 21 to form a fine bubble-containing liquid 23, and a mixing device 11 and a discharge pipe 2b that mix the sewage 21 with the sewage pipe 62. A liquid supply device 61 for supplying the oxygen-containing gas 31 to the mixing device 11 and a gas supply device 32 for supplying the oxygen-containing gas 31 to the mixing device 11.
In the water treatment device 1 shown in FIG. 1, the arrangement of the mixing device satisfies the following arrangement 1.
Arrangement 1: The mixing device 11 is arranged between the drain pipe 62 and the discharge pipe 2b, and the fine bubble-containing liquid 23 is discharged from the discharge pipe 2b as high-concentration oxygen-containing water 22.
The mixing device 11 may be fixed at an arbitrary position inside the drainage tank 2. It may be fixed to any fixing member inside the drainage tank via a movable guide (dotted line in FIG. 1).
The discharge pipe 2b is preferably filled with high-concentration oxygen-containing water 22. The discharge pipe 2b is preferably connected to the sewage pressure feed pipe 3. The sewage pressure feed pipe 3 preferably has an uphill slope. In the water treatment device 1 shown in FIG. 1, the high-concentration oxygen-containing water 22 is discharged from the discharge pipe 2b to the sewage pressure feed pipe 3.
In the water treatment device in which the arrangement of the mixing device satisfies the arrangement 2 (see FIGS. 4 and 5) and the water treatment device described in Japanese Patent No. 4195867 and JP-A-2019-85771, the sewage is filled with air inside the drainage tank. And oxygen are mixed. Therefore, suspended solids in the drainage tank may float due to air bubbles or oxygen bubbles, and scum may occur. However, in the water treatment device in which the arrangement of the mixing device satisfies the arrangement 2 and the water treatment device described in JP-A-2019-85771, sewage circulates between the drainage tank and the mixing device, so that the sewage circulates in the drainage tank. Since the entire sewage flows, the accumulation of sediment and the generation of scum in the drainage tank can be suppressed to some extent.
On the other hand, in the preferred embodiment of the water treatment device of FIG. 1 (and FIG. 3), the mixing device is arranged between the drain pipe and the discharge pipe, and the sewage is pumped between the drain pipe and the discharge pipe. And mix the oxygen-containing gas. In this embodiment, since the oxygen-containing gas is not introduced into the drainage tank, it is possible to suppress the generation of scum caused by the bubbles of the oxygen-containing gas inside the drainage tank, as compared with the arrangement 2.
Further, when the arrangement of the mixing device satisfies the arrangement 1, the ratio of the sewage mixed with the oxygen-containing gas by the mixing device to the entire sewage in the drainage tank can be increased as compared with the case where the arrangement 2 is satisfied. , It is easy to obtain water containing high concentration oxygen.

FIG. 2 is a schematic view of an example of a mixing device used in a water treatment device.
The mixing device 11 shown in FIG. 2 includes a processing tank having a storage chamber 12 in which the fine bubble-containing liquid 23 is stored. An injection port 13a of an injection path 15 for injecting sewage 21 and oxygen-containing gas 31 into the storage chamber 12 opens on the inner surface of the storage chamber 12, and the fine bubble-containing liquid 23 is discharged from the storage chamber 12. The discharge port 13b of the discharge path for the purpose is open.
The inlet 13a is arranged on the first inner surface 13 of the storage chamber 12.
The discharge port 13b is arranged on an inner surface (first inner surface 13 in FIG. 2) other than the second inner surface 14 facing the first inner surface 13 of the storage chamber 12.

FIG. 3 is a schematic view of another example of the water treatment apparatus of the present invention, and is an example in which the arrangement of the mixing apparatus satisfies the arrangement 1.
The water treatment device 1 shown in FIG. 3 further includes the following configuration in the water treatment device shown in FIG. 1.
In the water treatment device 1 shown in FIG. 3, the drain pipe 62 further includes a return valve 63 and a return flow path 64. In this case, the drainage pipe 62 includes a main flow path toward the discharge pipe 2b and a return flow path 64 branching from the drainage pipe 62 toward the drainage tank 2. By opening and closing the return valve 63, a part or all of the sewage can be supplied to the return flow path 64.
The water treatment device 1 shown in FIG. 3 includes a plurality of sets of a liquid supply device 61 and a drainage pipe 62. It is preferable that the set of the plurality of liquid supply devices 61 and the drain pipe 62 includes the return valve 63 and the return flow path 64, respectively. The water treatment device preferably includes 2 to 4 sets of the liquid supply device 61 and the drain pipe 62, and more preferably 2 sets.
In the water treatment device 1 shown in FIG. 3, the mixing device 11 is arranged at a position downstream of all the drain pipes 62.
The water treatment device 1 shown in FIG. 3 includes a dissolved oxygen concentration sensor 41 used as a water quality measuring instrument 40 for sewage 21, and a hydrogen sulfide concentration sensor 42 used for the gas phase of the drainage tank 2. With these sensors, it is possible to detect the water quality and the state of the gas phase of the sewage 21 in the drainage tank 2.
The water treatment device 1 shown in FIG. 3 includes a control device 50. The dissolved oxygen concentration sensor 41 and the hydrogen sulfide concentration sensor 42 used for the gas phase of the drainage tank 2 are connected to the control device 50 by wire or wirelessly. The control device 50 can control the liquid supply device 61, the gas supply device 32, the return valve 63, and the like.
In the case of a water treatment system in which another water treatment device (not shown) of the present invention is connected to the upstream of the water treatment device 1 shown in FIG. 3, the control device 50 of the water treatment device 1 shown in FIG. 3 is upstream. The liquid supply device, gas supply device, and return valve of the water treatment device on the side may be controlled.

FIG. 4 is a schematic view of another example of the water treatment apparatus of the present invention, and is an example in which the arrangement of the mixing apparatus satisfies the following arrangement 2.
Arrangement 2: The mixing device 11 is arranged in the return flow path 64 branching from the drain pipe 62, and the fine bubble-containing liquid 23 is returned to the drain tank 2.
In this case, the drainage pipe 62 includes a main flow path toward the discharge pipe 2b and a return flow path 64 branching from the drainage pipe 62 toward the mixing device 11.
A return flow path 64 (return flow path) may be provided in the middle of the drain pipe 62 for the purpose of measures against floating scum. In particular, when the drain tank 2 of the water treatment device 1 is used as a manhole pumping station and the liquid supply device 61 is used as a manhole pump, the return flow path 64 is often provided in the middle of the drain pipe 62. In the water treatment apparatus 1 shown in FIG. 4, the mixing apparatus 11 which is a highly efficient gas dissolving apparatus is arranged in the return flow path 64 branching from the drain pipe 62, so that the oxygen-containing gas efficiently does not require an additional pump. 31 can be mixed with sewage 21.
As a discharge path for discharging the fine bubble-containing liquid 23 from the storage chamber 12, it is preferable to return the fine bubble-containing liquid 23 below the water surface of the sewage 21 of the drain tank 2.
The water treatment device 1 shown in FIG. 4 preferably further includes a return valve 63 in the return flow path 64 to which the drain pipe 62 branches. By opening and closing the return valve 63, a part or all of the sewage can be supplied to the return flow path 64.
The water treatment device 1 shown in FIG. 4 is substantially the same as the configuration of the water treatment device 1 shown in FIG. 1 except that the arrangement of the mixing device 11 satisfies the arrangement 2.

FIG. 5 is a schematic view of another example of the water treatment apparatus of the present invention, and is an example in which the arrangement of the mixing apparatus satisfies the arrangement 2.
The water treatment apparatus 1 shown in FIG. 5 further includes the following configuration in the water treatment apparatus shown in FIG.
The water treatment device 1 shown in FIG. 5 includes a plurality of sets of a liquid supply device 61 and a drainage pipe 62. It is preferable that the set of the plurality of liquid supply devices 61 and the drain pipe 62 includes the return valve 63 and the return flow path 64, respectively.
In the water treatment device 1 shown in FIG. 5, the mixing device 11 is connected to and arranged in the return flow path 64 branching from one drainage pipe 62, and the other drainage pipes 62 are not connected to the mixing device 11. .. However, the plurality of mixing devices 11 may be connected to and arranged in the return flow path 64 branching from the plurality of drain pipes 62, respectively.
The water treatment device 1 shown in FIG. 5 includes a dissolved oxygen concentration sensor 41 used as a water quality measuring instrument 40 for sewage 21, and a hydrogen sulfide concentration sensor 42 used for the gas phase of the drainage tank 2. With these sensors, it is possible to detect the water quality and the state of the gas phase of the sewage 21 in the drainage tank 2.
Hereinafter, preferred embodiments of each part constituting the water treatment apparatus of the present invention will be described.

<Drain tank>
The water treatment apparatus of the present invention includes a drainage tank.
There are no particular restrictions on the drainage tank. For example, a drainage tank of an existing building or factory, a manhole pumping station, or the like may be used as a drainage tank. On the other hand, a new drainage tank may be provided.
The drainage tank may have a structure in which sewage flows continuously or a structure in which sewage flows in intermittently.
Sewage can flow into the drainage tank from an inflow channel provided at an arbitrary position in the drainage tank. The inflow channel may be provided below the water surface of the sewage inside the drainage tank, or may be provided above the water surface. It is preferable to provide the inflow channel below the water surface of the sewage inside the drainage tank from the viewpoint that the gas phase of the drainage tank is convected by the impact of the sewage falling on the water surface and the bad odor due to hydrogen sulfide can be suppressed. On the other hand, it is preferable to provide the inflow channel above the water surface of the sewage inside the drainage tank so that the sewage can freely fall from the viewpoint of suppressing the equipment cost.

(sewage)
The sewage used in the present invention is not particularly limited, and for example, sewage (sewage sludge), domestic wastewater, factory wastewater, and the like can be used as sewage.
The water treatment apparatus of the present invention can be used for sewage that can generate hydrogen sulfide. The water treatment apparatus of the present invention is preferably installed in a wastewater (irrigation) facility such as a building pit, a manhole or a factory provided in the basement of a building. Among these, the water treatment apparatus of the present invention is preferably installed as a manhole pumping station in a water treatment system composed of a manhole and a manhole pumping station.

<Mixing device>
The water treatment apparatus of the present invention includes a mixing apparatus in which oxygen-containing gas is mixed with sewage to obtain a fine bubble-containing liquid. In the water treatment apparatus of the present invention, the oxygen-containing gas can be dissolved in the sewage from the drainage tank by the mixing apparatus.
In the water treatment apparatus of the present invention, the arrangement of the mixing apparatus satisfies the following arrangement 1 or arrangement 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in the return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.

The mixing device preferably includes a treatment tank having a storage chamber in which the fine bubble-containing liquid is stored.
By reducing the bubble size of the oxygen-containing gas in the mixing device, the oxygen-containing gas can be easily dissolved in the sewage of the present invention.

The positional relationship between the drain tank and the mixing device is not particularly limited. For example, the mixing device may be arranged outside the drainage tank. When the mixing device is arranged outside the drainage tank, the maintenance of the mixing device can be easily performed.
However, as shown in FIG. 1, a mixing device may be arranged inside the drainage tank.
It is preferable that the mixing device is arranged vertically above the water surface of the sewage stored at the bottom of the drainage tank from the viewpoint of pumping up an appropriate amount of sewage and dissolving the oxygen-containing gas.

When the arrangement of the mixing device satisfies the arrangement 1 and the water treatment device includes a plurality of sets of the liquid supply device and the drain pipe, it is preferable that the mixing device is arranged at a position downstream of all the drain pipes.
With such a configuration, only one mixing device can be arranged to sufficiently suppress the generation of hydrogen sulfide and the generation of scum.

(Storage room and processing tank)
The inner surface of the storage chamber is opened with an injection port for injecting sewage and oxygen-containing gas into the storage chamber.
On the inner surface of the storage chamber, a discharge port for discharging the fine bubble-containing liquid from the storage chamber is opened.
The inlet is located on the first inner surface of the storage chamber.
The discharge port is preferably arranged on an inner surface other than the second inner surface facing the first inner surface of the storage chamber.
The shapes and sizes of the storage chamber, the treatment tank, the inlet and the discharge port are not limited, and are appropriately set according to the required processing capacity.

The shape of the storage chamber and the treatment tank preferably includes a top plate in the vertically upward direction, a bottom plate facing the top plate, and side surfaces connecting them.
The first inner surface of the reservoir in which the inlet is located is preferably one of the sides.
The inner surface other than the second inner surface facing the first inner surface of the storage chamber in which the discharge port is arranged is preferably one of the side surfaces, and more preferably the first inner surface.
The top plate and the bottom plate are preferably polygonal, more preferably quadrangular. That is, it is more preferable that the storage chamber and the treatment tank have a rectangular parallelepiped shape. Specifically, it is preferable that the treatment tank is a hollow rectangular parallelepiped and a storage chamber is formed inside. The treatment tank preferably includes a pair of upper and lower top plates and bottom plates, a pair of left and right left and right walls, and a pair of front and rear front and rear walls.

Hereinafter, preferred embodiments of the storage chamber and treatment tank used in the water treatment apparatus of the present invention will be described, but the water treatment apparatus of the present invention is not limited to the following preferred embodiments. As another embodiment of the water treatment apparatus of the present invention, the embodiments described in [0035] to [0252] of International Publication No. 2019/093283 can be mentioned, and the contents of this publication are referred to in the present specification. Be incorporated.

-An example of a preferred embodiment of a storage chamber and a treatment tank (aspect of FIG. 2)-
The top and bottom plates are horizontally arranged rectangular flat plates. The top plate is located directly above the bottom plate. The top plate and the bottom plate have the same shape, and are formed longer in the left-right direction than in the front-back direction.
The top plate constitutes the top of the storage chamber, and the bottom plate constitutes the bottom of the storage chamber. That is, the inner surface of the top plate is the inner surface of the top of the storage chamber, and the inner surface of the bottom plate is the inner surface of the bottom of the storage chamber. The inner surface of the top plate and the inner surface of the bottom plate face each other in the vertical direction.

The left and right walls are erected on the left and right edges of the bottom plate, respectively. The left side wall and the right wall extend vertically upward with respect to the bottom plate. The left side wall and the right wall have the same shape, and are formed longer in the vertical direction than in the front-rear direction.

Front and rear walls are erected on the front and rear edges of the bottom plate, respectively. The front and rear walls extend vertically upward with respect to the bottom plate. The front wall and the rear wall have the same shape, and are formed longer in the vertical direction than in the horizontal direction.

The left side wall, the right wall, the front wall and the rear wall form a square tubular body. The lower surface of the body is closed by the bottom plate, and the upper surface of the body is closed by the top plate.

The storage chamber is a rectangular parallelepiped space whose outer circumference is surrounded by a body and whose upper and lower surfaces are closed by a top plate and a bottom plate.
A pair of upper and lower inner surfaces, a pair of left and right inner surfaces, and a pair of front and rear inner surfaces are formed on the inner surface of the storage chamber.

The inner surface of the left side wall (first inner surface) and the inner surface of the right side wall (second inner surface) are the inner surfaces of the side portions of the storage chamber, and are raised with respect to the inner surface of the bottom plate. The inner surface of the left side wall and the inner surface of the right wall face each other in the left-right direction.
The inner surface of the front wall (third inner surface) and the inner surface of the rear wall (fourth inner surface) are the inner surfaces of the side portions of the storage chamber, and are raised with respect to the inner surface of the bottom plate. The inner surface of the front wall and the inner surface of the rear wall face each other in the front-rear direction.

The pair of inner surfaces facing each other on the left and right and the pair of inner surfaces facing each other on the front and back are arranged in a square cylinder shape.
In the mixing device of this embodiment, the distance between the inner surface of the left side wall and the inner surface of the right side wall is formed longer than the distance between the inner surface of the front wall and the inner surface of the rear wall.
As described above, in the storage chamber of this embodiment, the width in the left-right direction is formed larger than the width (depth) in the front-rear direction. As a result, the space in the storage chamber is formed into a flat rectangular parallelepiped that is wide in the left-right direction and narrow in the front-back direction.

As shown in FIGS. 1 and 2, the treatment tank of this embodiment has an injection path 15 for injecting sewage 21 and oxygen-containing gas 31 into the storage chamber 12, and a fine bubble-containing liquid 23 in the storage chamber 12. A discharge channel for discharging from the inside is provided.

The injection path is composed of an injection port 13a opened on the inner surface (first inner surface 13) of the left side wall, an injection hole communicating with the injection port, and an injection tube provided on the outer surface of the left side wall.

The inlet 13a is open to the inner surface (first inner surface 13) of the left side wall. The inlet 13a is a circular opening. The inlet 13a is arranged below the inner surface (first inner surface 13) of the left side wall. Further, the injection port 13a is arranged at the center of the inner surface of the left side wall in the front-rear direction.
The injection hole is a circular hole that communicates with the injection port 13a and penetrates the left side wall in the left-right direction.

The tip of the injection tube is attached to the outer surface of the left wall, and the injection tube communicates with the injection hole. The base end of the injection pipe is connected to a pipe extending from the gas supply device 32 and the liquid supply device 61, and sewage and oxygen-containing gas are supplied to the injection pipe together. Then, the liquid to be treated and the oxygen-containing gas are injected into the storage chamber 12 from the injection port 13a through the injection hole from the injection pipe.

The discharge path is composed of a discharge port 13b opened on the inner surface (first inner surface 13) of the left side wall, a discharge hole communicating with the discharge port 13b, and a discharge pipe provided on the outer surface of the left side wall.

The discharge port 13b is open to the inner surface (first inner surface 13) of the left side wall. The discharge port 13b is a circular opening. The discharge port 13b is arranged below the inner surface (first inner surface 13) of the left side wall. Further, the discharge port 13b is arranged at the center of the inner surface (first inner surface 13) of the left side wall in the front-rear direction.
The discharge hole is a circular hole that communicates with the discharge port 13b and penetrates the left side wall in the left-right direction.

The tip of the discharge pipe is attached to the outer surface of the left wall, and the discharge pipe communicates with the discharge hole. The base end of the drain pipe is connected to the pipe to the drain tank. Then, the fine bubble-containing liquid 23 is sent from the inside of the storage chamber 12 to the outside of the mixing device from the discharge port 13b through the discharge hole and the discharge pipe. Specifically, the fine bubble-containing liquid from the mixing device is discharged from the discharge pipe as high-concentration oxygen-containing water when the arrangement of the mixing device satisfies the arrangement 1, and is discharged when the arrangement of the mixing device satisfies the arrangement 2. It will be returned to the aquarium.

The inlet 13a and the outlet 13b of this embodiment are arranged below the central portion in the vertical direction of the inner surface (first inner surface 13) of the left side wall. Further, the injection port 13a and the discharge port 13b are arranged so as to sandwich the central portion in the vertical direction of the lower half of the inner surface (first inner surface 13) of the left side wall. The injection port 13a is arranged above the discharge port 13b.
In the water treatment apparatus of the present invention, it is preferable that the discharge port is arranged below the injection port and the opening area of the discharge port is formed to be 0.25 times or more and 1.0 times or less the opening area of the injection port. When the opening area of the discharge port is 0.25 times or more and 1.0 times or less the opening area of the injection port, when the sewage 21 and the oxygen-containing gas 31 are injected into the storage chamber, the sewage 21 and oxygen-containing gas in the storage chamber are contained. The pressure of the gas 31 becomes high. In this way, the sewage 21 and the oxygen-containing gas 31 injected into the storage chamber from the injection port are less likely to change their flows downward, so that the vortex flow of the sewage 21 and the oxygen-containing gas 31 is stabilized in the upper space of the storage chamber. Can be formed.
When the opening area of the discharge port is 0.25 times or more and less than 1.0 times the opening area of the injection port, the pressures of the sewage 21 and the oxygen-containing gas 31 in the storage chamber can be effectively increased. ..

When the sewage 21 and the oxygen-containing gas 31 are injected into the storage chamber 12 from the injection port 13a, the sewage 21 and the oxygen-containing gas 31 come into contact with the inner surface (second inner surface 14) of the right side wall, and the flow changes significantly. Then, the sewage 21 and the oxygen-containing gas 31 are swirled in the vertical direction in the storage chamber 12, and then the fine bubble-containing liquid 23 is discharged from the discharge port 13b on the inner surface (first inner surface 13) of the left side wall.

At this time, in the storage chamber 12 of this embodiment, the upper vortex flow S1 and the lower vortex flow S2 are formed by the sewage 21 and the oxygen-containing gas 31.
Then, the sewage 21 and the oxygen-containing gas 31 in the storage chamber 12 flow from the upper vortex flow S1 to the lower vortex flow S2, and the fine bubble-containing liquid 23 is discharged from the discharge port 13b to the discharge hole. Then, the fine bubble-containing liquid 23 is sent to the outside of the mixing device 11 (discharge pipe 2b or drain tank 2) through the discharge pipe.

In the mixing device 11 of this embodiment, since the injection port 13a and the discharge port 13b are not formed on the two facing surfaces, the sewage 21 and the oxygen-containing gas 31 are easily discharged from the discharge port 13b without being caught in the vortex. , Can be reduced. As a result, the sewage 21 and the oxygen-containing gas 31 flow in a long path in the storage chamber 12, and the behavior of the sewage 21 and the oxygen-containing gas 31 in the storage chamber 12 is greatly disturbed. As a result, the sewage 21 and the oxygen-containing gas 31 are sufficiently in contact with each other, so that the sewage 21 and the oxygen-containing gas 31 can be mixed well.
Further, since the storage chamber 12 is a flat space, the direction vector of the eddy current becomes two-dimensional. This makes it possible to stabilize the vortex flow formed in the storage chamber 12.
Therefore, in the mixing device 11 of this embodiment, the dissolved oxygen concentration of the fine bubble-containing liquid 23 increases due to oxygen substitution.

Further, in the mixing device 11 of this embodiment, the injection pipe (the end of the injection path 15) connected to the injection port 13a and the discharge pipe connected to the discharge port 13b are not linearly arranged on both sides of the treatment tank. .. Therefore, the installation space of the mixing device 11 can be reduced, and the degree of freedom in the layout of the mixing device 11 can be increased.

In the mixing device 11 of this embodiment, the length of the storage chamber 12 in the left-right direction is 95 mm, and the length of the storage chamber 12 in the front-rear direction is 28 mm. Further, the length of the storage chamber 12 in the vertical direction is 140 mm.
That is, in the storage chamber 12 of this embodiment, the distance (length in the left-right direction) between the inner surface of the left side wall (first inner surface 13) and the inner surface of the right side wall (second inner surface 14) is the inner surface of the front wall. It is formed to be 3.4 times the distance (length in the front-rear direction) between the surface and the inner surface of the rear wall.

In the mixing device 11 of this embodiment, the problem that the sewage 21 and the oxygen-containing gas 31 are easily discharged from the discharge port 13b without being caught in the vortex can be reduced. Therefore, the sewage 21 and the oxygen-containing gas 31 flow in a long path while being caught in the vortex in the storage chamber 12, and the behavior of the sewage 21 and the oxygen-containing gas 31 is greatly disturbed in the storage chamber 12.
The mixing device 11 of this embodiment can mix the sewage 21 and the oxygen-containing gas 31 well, and can reduce the installation space. Therefore, the sewage 21 and the oxygen-containing gas 31 can be efficiently mixed in a small space.

In the mixing device 11 of this embodiment, the injection port 13a and the discharge port 13b are arranged below the inner surface (first inner surface 13) of the left side wall, but the injection port 13a and the discharge port 13b are arranged on the inner surface (first) of the left side wall. It may be arranged on the upper part of one inner surface 13). An embodiment in which the discharge port is arranged below the injection port and the height from the lower edge of the first inner surface to the center position of the injection port is 0.5 times or more and 0.9 times or less the height of the first inner surface. Is also preferable.

In the mixing device 11 of this embodiment, the injection port 13a and the discharge port 13b are arranged at the center of the inner surface (first inner surface 13) of the left side wall in the front-rear direction, but the injection port 13a and the discharge port 13b are arranged on the left side wall. It may be arranged in the front part or the rear part of the inner surface (first inner surface 13) of the above. Further, the injection port 13a and the discharge port 13b may be displaced in the front-rear direction.

In the mixing device 11 of this embodiment, the injection port 13a and the discharge port 13b are opened on the inner surface (first inner surface 13) of the left side wall, but the inner surface (second inner surface 14) of the right side wall, the inner surface of the front wall, or The inlet 13a and the outlet 13b may be opened on the inner surface of the rear wall.

In the mixing device 11 of this embodiment, the length of the storage chamber 12 in the left-right direction is formed to be 3.4 times the length in the front-rear direction, but the length of the storage chamber 12 in the left-right direction is the length in the front-rear direction. When it is between 2 times and 4 times the size, the vortex flow formed in the storage chamber 12 tends to be stable. Further, when the length of the storage chamber 12 in the left-right direction is between 2.5 times and 3.5 times the length in the front-rear direction, the vortex flow formed in the storage chamber 12 can be more stabilized. Therefore, the sewage 21 and the oxygen-containing gas 31 can be mixed well.

(Fine bubble-containing liquid)
Generally, a fine bubble is a fine bubble having a bubble diameter of 100 μm or less. Among the fine bubbles, those having a bubble diameter of 1 μm or more are called microbubbles, and those having a bubble diameter of less than 1 μm are called ultrafine bubbles. Ultrafine bubbles are colorless and transparent, so they are invisible to the eye and remain in water for a long time, that is, they are highly stable in the liquid and have a lifespan of several weeks to several months, and rise in water. The speed is very slow.
In the present invention, it is preferable to use an ultrafine bubble having a bubble diameter of 500 nm or less. In the present invention, the bubble diameter of the oxygen-containing gas contained in the fine bubble-containing liquid is more preferably 300 nm or less, and particularly preferably 150 nm or less. The lower limit of the bubble diameter of the oxygen-containing gas contained in the fine bubble-containing liquid is not particularly limited, but may be, for example, 10 nm or more, and may be 50 nm or more.

In arrangement 2, the pipe for discharging the fine bubble-containing liquid from the mixing device to the drain tank preferably has a portion extending vertically downward from the mixing device. This pipe does not have to reach the surface of the sewage, but as shown in FIGS. 4 and 5, it was dissolved in the drainage that it reached the surface of the drainage stored at the bottom of the drainage tank. It is preferable from the viewpoint of making it difficult to dissipate oxygen.

<Liquid supply device>
The water treatment device of the present invention includes a liquid supply device that supplies sewage to a mixing device and a discharge pipe via a drain pipe.
The liquid supply device generates pressure for pumping the sewage inside the drainage tank and pumping it to the mixing device and / or the discharge pipe.

The positional relationship between the drain tank and the liquid supply device is not particularly limited. For example, as shown in FIGS. 1 and 3 to 5, a liquid supply device may be arranged inside the drainage tank. Further, a pipe for separating sewage may be provided outside the drainage tank, and a liquid supply device may be arranged in the pipe. It is preferable that the liquid supply device is arranged inside the drainage tank from the viewpoint of miniaturization of the water treatment device.
The liquid supply device is preferably arranged below the surface of the sewage inside the drainage tank, and more preferably at the bottom of the drainage tank.
The sewage inside the drainage tank is pumped up by the liquid supply device and pumped through the drainage pipe or the return flow path. It is preferable that the liquid supply device also serves as a liquid supply pump to the mixing device and a drainage pump from the viewpoint of miniaturization of the water treatment device.

<Drainage pipe>
It is preferable that one end of the drainage pipe is connected to the liquid supply device and the other end is connected to at least one of the discharge pipe and the injection pipe to the mixing device. In arrangement 1, one end is preferably connected to the liquid supply device and the other end is preferably connected to the injection tube to the mixing device. In arrangement 2, one end is preferably connected to the liquid supply device, the other end is connected to the discharge tube, and the other end is connected to the injection tube to the mixing device.
The end connected to the liquid supply device is preferably the lower end.
The drainage pipe preferably has a portion extending in the vertical vertical direction.

It is preferred that the drainage pipe be provided with a return valve and a return flow path. By opening the return valve, sewage can be returned to the drainage tank from the return flow path, which is preferable from the viewpoint of stirring the inside of the drainage tank to reduce the retention points. When it is not necessary to return the sewage from the return flow path to the drainage tank, the return valve can be closed.
In particular, when the arrangement of the mixing device satisfies the arrangement 2, it is preferable to provide a return valve between the drain pipe and the return flow path from the viewpoint of easily controlling the inflow of sewage into the mixing device.

The return flow path preferably has a portion extending vertically downward. This return flow path may reach the surface of the sewage.
If the arrangement of the mixing device satisfies arrangement 2, it is preferred that the end of at least one return channel be connected to the injection tube to the mixing device.

<Gas supply device>
The water treatment apparatus of the present invention includes a gas supply apparatus that supplies an oxygen-containing gas to the mixing apparatus.

The method of supplying the oxygen-containing gas by the gas supply device is not particularly limited, and any method usually used in the technical field of the water treatment device can be freely selected and used.

It is preferable that the gas supply device is inserted with a supply pipe for injecting an oxygen-containing gas. The supply pipe is preferably a cylindrical member, and preferably has an open tip.
The base end of the supply pipe is preferably connected to the injection path. Then, it is preferable that the oxygen-containing gas supplied from the supply pipe is injected into the flow path of the injection path.

The flow rate and injection amount of the oxygen-containing gas can be freely set according to the dissolved oxygen concentration and the purpose of the sewage or the high-concentration oxygen-containing water.

(Oxygen-containing gas)
The oxygen-containing gas is not particularly limited except that it contains oxygen. As the oxygen-containing gas, a gas suitable for improving the water quality of sewage can be used. For example, air (atmosphere) may be used as the oxygen-containing gas, or high-concentration oxygen may be used. It is preferable that the oxygen-containing gas is the air outside the drainage tank from the viewpoint of easily providing a low-cost water treatment apparatus.

The gas supply source for supplying the oxygen-containing gas is not particularly limited. For example, when the oxygen-containing gas has a high concentration of oxygen, a gas generator such as a gas cylinder or a PSA (Pressure Swing Attachment) device can be used as the gas supply source.
The water treatment apparatus of the present invention can dissolve oxygen-containing gas in sewage with high efficiency, and can obtain the effect of stably suppressing the generation of hydrogen sulfide with a small amount of oxygen-containing gas input. Therefore, when a gas cylinder, particularly a high-pressure cylinder, is used as the gas supply source, the replacement frequency and replacement cost of the gas supply source can be reduced. Further, when a gas generator is used as a gas supply source, power consumption can be reduced by shortening the operation time, and the initial cost and installation space can be reduced because a device having specifications having a low gas generation capacity can be used.
The flow rate and injection amount of the oxygen-containing gas can be freely set according to the dissolved oxygen concentration and the purpose of the sewage or the high-concentration oxygen-containing water.

(Water containing high concentration oxygen)
High-concentration oxygen-containing water can be obtained by dissolving the oxygen-containing gas in the sewage supplied to the drainage tank.
The high-concentration oxygen-containing water discharged from the discharge pipe of the drainage tank is a liquid having a higher dissolved oxygen concentration than the sewage flowing in from the inflow channel.

<Discharge pipe>
The sewage pumped through the drain pipe is finally pumped into the discharge pipe.
The discharge pipe is a pipe connected to the outside of the drainage tank.
When the arrangement of the mixing device satisfies the arrangement 1, the mixing device is arranged between the drain pipe and the discharge pipe. The sewage becomes a fine bubble-containing liquid by passing through the mixing device. Then, the fine bubble-containing liquid is pressure-fed from the discharge pipe to the outside of the drainage tank as high-concentration oxygen-containing water.
When the arrangement of the mixing device satisfies the arrangement 2, it is preferable that the discharge pipe is connected to the drain pipe. In this case, the sewage becomes a fine bubble-containing liquid by passing through the mixing device, and the fine bubble-containing liquid is returned to the drainage tank. As a result, the sewage in the drainage tank having a sufficiently high oxygen concentration is pumped from the discharge pipe to the outside of the drainage tank as high-concentration oxygen-containing water.
The downstream end of the discharge pipe is preferably connected to the sewage pressure feed pipe, and more preferably connected to the uphill sewage pressure feed pipe. With this configuration, the discharge pipe can be filled with sewage or high-concentration oxygen-containing water. As a result, the oxygen-containing gas can be efficiently dissolved in the sewage.

<Water quality measuring instrument, hydrogen sulfide concentration sensor, control device>
The water treatment apparatus of the present invention preferably further includes at least one of a water quality measuring instrument and a hydrogen sulfide concentration sensor.

The water quality measuring instrument may be provided inside the drainage tank or outside the drainage tank. The water quality measuring instrument is preferably provided in the drainage tank.
In the present invention, the water quality measuring instrument is preferably at least one of the dissolved oxygen concentration sensor and the redox potential sensor, and more preferably the dissolved oxygen concentration sensor.
The water quality measuring instrument preferably includes a sensor arranged so as to come into contact with sewage and / or water containing high oxygen concentration. When the dissolved oxygen concentration sensor is used, the dissolved oxygen concentration sensor can be arranged at the bottom of the drainage tank to measure the dissolved oxygen concentration of the sewage in the drainage tank. Further, the dissolved oxygen concentration sensor and the redox potential sensor may be arranged in an inflow passage, a drain pipe, or a discharge pipe.

It is preferable that the hydrogen sulfide concentration sensor is arranged in the gas phase in the drain tank and measures the hydrogen sulfide concentration in the drain tank.

The water treatment device of the present invention preferably further includes a control device.
The control device is preferably a computer that controls the drive of the liquid supply device and / or the gas supply device. It is preferable that the control device further includes a storage unit. Each process of the control device can be realized by the CPU (central processing unit) executing the program stored in the storage unit.

In a preferred embodiment of the present invention, the control device is liquid depending on at least one of the water quality of sewage and / or high-concentration oxygen-containing water measured by the water quality measuring instrument and the hydrogen sulfide concentration measured by the hydrogen sulfide concentration sensor. It is preferable to control the supply device and the gas supply device. It is more preferable that the control device controls the liquid supply device and the gas supply device according to at least one of the liquid quality of the sewage measured by the liquid quality measuring instrument and the hydrogen sulfide concentration measured by the hydrogen sulfide concentration sensor.
For example, the control device preferably drives a liquid supply device and / or a gas supply device or an arbitrarily provided return valve when the dissolved oxygen concentration of sewage measured by the dissolved oxygen concentration sensor is equal to or less than a set value. .. For example, the control device drives a liquid supply device and a gas supply device when the dissolved oxygen concentration of the sewage becomes low (when the sewage is in a state where hydrogen sulfide is likely to be generated). Further, when the arrangement of the mixing device satisfies the arrangement 2, the return valve is further opened. By these controls, sewage and oxygen-containing gas can be easily injected into the mixing device, and the amount of oxygen-containing gas to be dissolved in the sewage can be increased.
The control device may stop the liquid supply device and / or the gas supply device when the dissolved oxygen concentration of the sewage or the high-concentration oxygen-containing water measured by the dissolved oxygen concentration sensor becomes higher than the set value. Further, when the arrangement of the mixing device satisfies the arrangement 2, the return valve provided arbitrarily may be driven to be in the closed state.
When the hydrogen sulfide concentration sensor measures the hydrogen sulfide concentration in the drainage tank, the control device can similarly control the liquid supply device and / or the gas supply device and the return valve provided arbitrarily. That is, it is preferable that the control device drives the liquid supply device and / or the gas supply device when the hydrogen sulfide concentration in the drain tank measured by the hydrogen sulfide concentration sensor is equal to or higher than the set value. Further, when the arrangement of the mixing device satisfies the arrangement 2, it is preferable to further open the return valve.

The water treatment apparatus of the present invention may further include a time measuring device. The time measuring device can measure the elapsed time and the time since the start of water treatment. The time measuring device is not particularly limited, and a known timer or clock can be used. The time measuring device may be provided as a part of the control device.
It is preferable that the control device controls the liquid supply device and / or the gas supply device and the return valve optionally provided according to the time measured by the time measuring device.
For example, the control device drives a liquid supply device and / or a gas supply device and an optional return valve for a preset time on the time measuring device. For example, during times (hours and days) when there is a lot of sewage flowing into the drainage tank, a return valve that drives the liquid supply device and / or the gas supply device regardless of the measured value of the water quality measuring device and is arbitrarily provided. Is preferably in an open state.

<Other equipment>
The water treatment device may include a portion having other functions. For example, various sensors such as a water level sensor (not shown) for measuring the water level of sewage in the drainage tank may be connected to the control device.

[Water treatment system]
The water treatment system of the present invention includes a plurality of water treatment devices of the present invention.
In the water treatment system of the present invention, the water treatment device further includes at least one of a liquid quality measuring device and a hydrogen sulfide concentration sensor and a control device, and the sewage liquid measured by the liquid quality measuring device in the downstream water treatment device. It is preferable that the control device of the upstream water treatment device feed-back controls the liquid supply device and the gas supply device according to the quality and at least one of the hydrogen sulfide concentration measured by the hydrogen sulfide concentration sensor. At this time, if the arrangement of the mixing device satisfies the arrangement 2, it is preferable to further control the return valve.

FIG. 6 is a schematic view of an example of a water treatment system using the water treatment apparatus of the present invention.
In the water treatment system shown in FIG. 6, it is preferable that the water treatment apparatus 1 and / or the manhole 101 of the present invention are connected via the sewage pressure feed pipe 3 or the sewage pipe 4. In the water treatment system shown in FIG. 6, the drainage tank of the water treatment apparatus 1 of the present invention is used as a manhole pumping station, and the drainage pump is used as a manhole pump.
In the water treatment system shown in FIG. 6, it is preferable that the upstream manhole 101 and the downstream manhole 101 are connected by a downward slope sewage pipe 4 from the upstream to the downstream.
Further, it is preferable that the upstream manhole 101 and the downstream water treatment device 1 are connected by a downward slope sewage pipe 4 from the upstream to the downstream. In this case, it is preferable to arrange the inflow path of the water treatment device 1 so as to be lower than the water surface in the drainage tank.

On the other hand, it is preferable that the upstream water treatment device 1 and the downstream manhole 101 are connected by an uphill sewage pump pipe 3 from the upstream to the downstream.
Further, it is preferable that the upstream water treatment device 1 and the downstream water treatment device 1 are connected by an uphill sewage pumping pipe 3 from the upstream to the downstream. In this way, two or more water treatment devices of the present invention may be continuously connected. In this case, the high-concentration oxygen-containing water 22 obtained in the upstream can be used as the sewage 21 in the water treatment device 1 further downstream to obtain the high-concentration oxygen-containing water 22 having a higher oxygen concentration.

The water (sewage 21 or high-concentration oxygen-containing water 22) introduced into the water treatment device 1 or the manhole 101 downstream from the uphill sewage pressure feed pipe 3 is introduced into the gas phase of the downstream water treatment device 1 or the manhole 101. You may. The water may then be dropped towards the surface of the water in the drain or manhole (see dashed line in FIG. 6). When the gas phase of the drainage tank or the manhole is convected due to such a fall of water, the problem of bad odor due to hydrogen sulfide heavier than air is likely to occur. On the other hand, according to the water treatment apparatus of the present invention, the generation of hydrogen sulfide can be suppressed, so that even when the gas phase of the drainage tank or the manhole is convection due to such a fall of water, hydrogen sulfide heavier than air is used. The foul odor can be suppressed.
On the other hand, the inflow path of the water treatment device 1 (not shown in FIG. 6) may be arranged so as to be lower than the water surface in the drainage tank.

[Water treatment method]
The water treatment method of the present invention is a water treatment method for dissolving an oxygen-containing gas in sewage supplied to a drainage tank and discharging it as high-concentration oxygen-containing water from a discharge pipe, and the sewage contains oxygen in a mixing device. It includes a mixing step of mixing gas to make a fine bubble-containing liquid, a liquid supply step of supplying sewage to a mixing device and a discharge pipe via a drain pipe, and a gas supply step of supplying oxygen-containing gas to the mixing device. , The arrangement of the mixing device satisfies the following arrangement 1 or arrangement 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in the return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank.
The water treatment method of the present invention is preferably a method for suppressing the generation of hydrogen sulfide.
According to the water treatment method of the present invention, even if sewage stays inside a sewage pumping pipe or the like in a full pipe state and hydrogen sulfide can be generated, the generation of hydrogen sulfide is stable during normal operation. It can be suppressed and the cost is low. In particular, when the arrangement of the mixing device satisfies the arrangement 1 or 2, the mixing device mixes the oxygen-containing gas with the sewage to obtain a fine bubble-containing liquid, so that water treatment with high oxygen dissolution efficiency can be performed. Further, as compared with the case where oxygen is directly supplied to the entire sewage in the drainage tank, the problem that the oxygen supplied to the sewage is dissipated into the atmosphere does not occur, and the generation of hydrogen sulfide can be stably suppressed.
In particular, when the arrangement of the mixing device satisfies the arrangement 1, the oxygen-containing gas can be supplied as a fine bubble to the vicinity of the upstream of the sewage pumping pipe having an uphill slope where sewage stays. Therefore, the gas dissolution efficiency can be improved, the position where hydrogen sulfide is likely to be generated can be set to an aerobic state, and the generation of hydrogen sulfide can be sufficiently suppressed even if the supply of oxygen-containing gas is small.

In a preferred embodiment of the water treatment method of the present invention, the quality of sewage is measured, and a control device drives a liquid supply device and / or a gas supply device according to the measurement result. In this aspect, it is possible to save energy in water treatment by the water treatment device as compared with the case where these devices are constantly driven.

Other preferred embodiments of the water treatment method of the present invention are the same as the preferred embodiments of the water treatment apparatus of the present invention.

1 Water treatment device 2 Drainage tank 2a Inflow path 2b Discharge pipe 3 Sewage pressure feed pipe 4 Sewage pipe 11 Mixing device 12 Storage chamber 13 First inner surface 13a Injection port 13b Outlet port 14 Second inner surface 15 Injection passage 21 Sewage 22 High concentration oxygen content Water 23 Fine bubble-containing liquid 31 Oxygen-containing gas 32 Gas supply device 40 Water quality measuring instrument 41 Dissolved oxygen concentration sensor 42 Hydrogen sulfide concentration sensor 50 Control device 61 Liquid supply device 62 Drain pipe 63 Return valve 64 Return flow path 101 Manhole

Claims (13)

It is a water treatment device for dissolving oxygen-containing gas in sewage supplied to the drainage tank and discharging it as high-concentration oxygen-containing water from the discharge pipe.
A mixing device that mixes oxygen-containing gas with the sewage to obtain a fine bubble-containing liquid.
A liquid supply device that supplies the sewage to the mixing device and the discharge pipe via the drain pipe, and
A gas supply device for supplying the oxygen-containing gas to the mixing device is provided.
A water treatment device in which the arrangement of the mixing device satisfies the following arrangement 1 or 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as the high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in a return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank. The water treatment device according to claim 1, wherein the discharge pipe is filled with the high-concentration oxygen-containing water and is connected to a sewage pressure feed pipe having an ascending slope. A plurality of sets of the liquid supply device and the drain pipe are provided.
The water treatment device according to claim 1 or 2, wherein the mixing device is arranged at a position downstream of all the drain pipes. Satisfy the above arrangement 2
The water treatment apparatus according to any one of claims 1 to 3, further comprising a return valve between the drain pipe and the return flow path. The water treatment apparatus according to any one of claims 1 to 4, wherein the oxygen-containing gas is air outside the drainage tank. The water treatment device according to any one of claims 1 to 5, wherein the fine bubble-containing liquid at the outlet of the mixing device contains the oxygen-containing gas having a bubble diameter of 500 nm or less. The mixing device includes a processing tank having a storage chamber in which the fine bubble-containing liquid is stored.
On the inner surface of the storage chamber,
In addition to opening the injection port of the injection path for injecting the sewage and the oxygen-containing gas into the storage chamber,
The discharge port of the discharge path for discharging the fine bubble-containing liquid from the storage chamber is open.
The inlet is located on the first inner surface of the reservoir.
The water treatment apparatus according to any one of claims 1 to 6, wherein the discharge port is arranged on an inner surface other than the second inner surface facing the first inner surface of the storage chamber. The water treatment apparatus according to any one of claims 1 to 7, wherein the drainage tank is a manhole pumping station. Further, at least one of the liquid quality measuring instrument and the hydrogen sulfide concentration sensor and a control device are provided, and the liquid quality of the sewage measured by the liquid quality measuring instrument and the hydrogen sulfide concentration sensor measured in the water treatment apparatus. The water treatment device according to any one of claims 1 to 8, wherein the control device controls the liquid supply device and the gas supply device according to at least one of the hydrogen sulfide concentrations. A water treatment system including a plurality of water treatment devices according to any one of claims 1 to 9. The water treatment device further includes at least one of a liquid quality measuring device and a hydrogen sulfide concentration sensor, and a control device.
According to at least one of the liquid quality of the sewage measured by the liquid quality measuring device in the water treatment apparatus downstream and the hydrogen sulfide concentration measured by the hydrogen sulfide concentration sensor, the water treatment apparatus upstream thereof. The water treatment system according to claim 10, wherein the control device feedback-controls the liquid supply device and the gas supply device. It is a water treatment method for dissolving oxygen-containing gas in sewage supplied to a drainage tank and discharging it as high-concentration oxygen-containing water from a discharge pipe.
In the mixing device, the mixing step of mixing oxygen-containing gas with the sewage to obtain a fine bubble-containing liquid, and
A liquid supply step of supplying the sewage to the mixing device and the discharge pipe via the drain pipe, and
A gas supply step for supplying the oxygen-containing gas to the mixing device is provided.
A water treatment method in which the arrangement of the mixing device satisfies the following arrangement 1 or 2.
Arrangement 1: The mixing device is arranged between the drain pipe and the discharge pipe, and the fine bubble-containing liquid is discharged from the discharge pipe as the high-concentration oxygen-containing water.
Arrangement 2: The mixing device is arranged in a return flow path branching from the drain pipe, and the fine bubble-containing liquid is returned to the drain tank. The water treatment method according to claim 12, which is a method for suppressing the generation of hydrogen sulfide.

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