JP2020163326A - Water treatment system - Google Patents

Abstract

To provide a water treatment system that can sufficiently reduce a frequency of maintenance.SOLUTION: There is provided a water treatment system 1, including: an intake unit 2a of groundwater 200; an outlet unit 2b for discharging treated water to outside of a well 100; a flow path 2 having a region extending vertically in at least a part between the intake unit 2a and the outlet unit 2b; a pump 3 that is connected to the intake unit 2a of the flow path 2 and introduces the groundwater 200 into the flow path 2; and a water treatment unit 4 connected to the region of the flow path 2 from the intake unit 2a so as to maintain liquid-tightness, and configured to generate treated water from the groundwater 200 in the well 100.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water treatment system.

The groundwater pumped from the well is treated by a water treatment device and then used for domestic water, industrial water, agricultural water, and the like.
According to Patent Document 1, as a conventional water treatment apparatus, a water pipe inserted in a well, a submersible pump connected to the lower end of the water pipe, a water pipe connected to the upper end of the water pipe, and a water pipe are used. An example is provided with a raw water tank for storing the raw water, a water treatment unit such as a pretreatment device or a filtration treatment device, and a treated water tank for storing the treated water.

Japanese Unexamined Patent Publication No. 2014-008435

The conventional water treatment apparatus described in Patent Document 1 has the following problems.
It costs a lot to install treatment equipment such as a raw water tank for storing raw water and a water treatment unit for treating raw water.
In addition, when pumping groundwater, oxygen in the air is mixed with the groundwater, and metal ions contained in the groundwater are oxidized, which causes clogging of the pumping pipe and the water discharge pump.
In addition, the frequency of maintenance of processing equipment and replacement of consumables increases, resulting in high running costs.
Therefore, it is difficult to operate the water treatment apparatus continuously for a long time.

The present invention provides a water treatment system that can sufficiently reduce the frequency of maintenance.

As a result of diligent studies to solve the above problems, the present inventors directly supply the groundwater pumped by the pump to the water treatment section in the flow path through which the groundwater pumped from the well flows, and the water quality of the groundwater is improved. We have found that by performing water treatment before the change, the frequency of maintenance can be sufficiently reduced and continuous operation can be performed for a long time without installing equipment such as a groundwater tank, and the present invention has been completed.

That is, the present invention has the following aspects.
[1] A water treatment system that generates treated water from groundwater in a well.
A flow path having a groundwater intake portion, an outlet portion for discharging treated water to the outside of the well, and a region extending vertically and vertically in at least a part between the intake portion and the outlet portion.
A pump connected to the intake portion of the flow path and introducing the groundwater into the flow path.
A water treatment system comprising a water treatment unit connected to the region of the flow path so as to maintain liquidtightness from the water intake unit.
[2] The water treatment system according to [1], further comprising a gas supply means for supplying an inert gas having a specific gravity higher than that of air into the well.
[3] The water treatment system according to [1] or [2], wherein the water treatment unit is installed so that the groundwater is treated while flowing substantially vertically upward.
[4] The water treatment system according to any one of [1] to [3], wherein the water treatment unit is located in a well.
[5] The water treatment system according to any one of [1] to [4], wherein the water treatment unit is located below the surface of the groundwater in the well.
[6] The water treatment system according to any one of [1] to [3], wherein the water treatment unit is located outside the entrance of the well.
[7] The water treatment system according to [4] or [5], wherein the water treatment unit contains only a filter medium.
[8] The water treatment system according to [6], wherein the water treatment unit includes a filtration device having an adsorption functional material and a filter medium.
[9] The water treatment system according to [7] or [8], wherein the filter medium contains at least one of a precision filter membrane, an ultrafiltration membrane, a nanofilter membrane, and a back-penetration membrane.
[10] The water treatment system according to any one of [1] to [9], wherein the flow path includes a pumping pipe inserted into a well.
[11] The water treatment system according to [10], wherein the pumping pipe extends outside the entrance of the well.
[12] The water treatment system according to [10] or [11], wherein the region is the pumping pipe.

According to the water treatment system of the present invention, the frequency of maintenance can be sufficiently reduced without installing equipment such as a raw water tank. Therefore, the water treatment system of the present invention can be continuously operated for a long time.

It is a schematic block diagram which shows an example of the water treatment system of this invention. It is a schematic block diagram which shows another example of the water treatment system of this invention. It is a schematic block diagram which shows another example of the water treatment system of this invention. It is a schematic block diagram which shows another example of the water treatment system of this invention.

"~" Indicating a numerical range means that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.
Directly supplying the water treatment device from the pump means that the water treatment device is connected to the flow path so as to maintain liquidtightness from the water intake section (that is, a state in which the external air is prevented from entering the flow path). , Means that groundwater can be supplied to the water treatment equipment.
The term "extending up and down in the vertical direction" does not mean that the vertical direction is strictly interpreted, and includes the case where the invention is inclined in any direction from the vertical direction within a range that does not impair the effect of the present invention.
The dimensional ratios in FIGS. 1 to 4 are different from the actual ones for convenience of explanation.

<Water treatment system>
FIG. 1 is a schematic configuration diagram showing an example of the water treatment system of the present invention.
The water treatment system 1 includes a pumping pipe 20 inserted into the well 100 and extending from the underground to the ground, a submersible pump (pump) 3 connected to the lower end of the pumping pipe 20 and immersed in the groundwater 200 in the well 100. A water treatment device that connects to the upper end of the pumping pipe 20 and extends horizontally and connects to the pumping pipe 20 below the water surface of the groundwater 200 in the well 100 to treat the groundwater pumped from the submersible pump 10. A (water treatment unit) 4 and a gas supply means 5 for supplying an inert gas having a specific gravity higher than that of air into the well 100 are provided.

The well 100 has a bottomed tubular well pipe 104 inserted into a drilling hole 102 excavated downward from the ground to a pressure aquifer 204 below the unzoned aquifer 202. Near the bottom of the well pipe 104, an intake port 104a for taking in the groundwater 200 gushing from the pressure aquifer 204 into the well pipe 104 is formed at the position of the pressure aquifer 204. A wire mesh (not shown) is attached to the water intake port 104a to prevent sand or the like from entering the well pipe 104.
The well 100 is opened. The open state means that a sealing member such as a sealing member is not provided at the upper end of the well pipe 104 of the well 100. A member that is not a sealing member may be provided. For example, the well 100 may be covered with a lid (not shown) having air holes to supply the inert gas. If the well 100 is covered, it is possible to prevent dust such as dead leaves from being mixed into the well 100.

In the water treatment system 1 of the present invention, the pumping pipe 20 and the water guiding pipe 22 form the flow path 2.
The flow path 2 extends vertically up and down at least a part between the intake portion 2a of the groundwater 200, the outlet portion 2b for discharging the treated water to the outside of the well 100, and the intake portion 2a and the outlet portion 2b. Has an area.
The water intake portion 2a is the lower end of the pumping pipe 20. A submersible pump 3 is connected to the water intake unit 2a.
The outlet portion 2b is the end of the water pipe 22. The treated water may be used directly from the outlet portion 2b, or the outlet portion 2b may be directly connected to the equipment on the secondary side. Further, a treatment water tank may be provided at the outlet portion 2b.
The region extending vertically and vertically is the pumping pipe 20. A water treatment device 4 is connected to the pumping pipe 20 so as to maintain liquidtightness from the water intake unit 2a.
The pumping pipe 20 preferably extends outside the entrance of the well 100 (in other words, has a portion extending above the entrance of the well 100).

The existing water pipe 22 is usually provided with an air intake port (not shown). If the inside of the pumping pipe 20 is filled with groundwater when the submersible pump 3 is stopped, the load at the start of operation of the submersible pump 3 becomes large due to the water pressure due to the head difference. Therefore, when the submersible pump 3 is stopped, it is common practice to take in air from the air intake port into the water pipe 22 and the pumping pipe 20 to lower the head of the groundwater in the pumping pipe 20.

The submersible pump 3 is connected to a water intake portion 2a which is the lower end of the pumping pipe 20 constituting the flow path 2. The submersible pump 3 is immersed in the groundwater 200 in the well 100.
The submersible pump 3 is not particularly limited as long as the groundwater 200 can be introduced into the flow path 2. Examples of the submersible pump 3 include a submersible cascade pump, a submersible centrifugal pump, a submersible turbine pump, a submersible mixed flow pump, and the like.
The submersible pump 3 may be provided with a check valve that suppresses the backflow of groundwater in the pumping pipe 20.

When groundwater easily escapes from the end (outlet portion 2b) of the water pipe 22 when the submersible pump 3 is stopped, it is preferable to provide a valve (not shown) in the middle of the water pipe 22. Examples of the valve include a solenoid valve, a check valve, and the like, and a solenoid valve that can be automatically opened and closed according to the operation of the submersible pump 3 is preferable.

The water treatment device 4 treats the groundwater in the well 100 to generate treated water.
The water treatment device 4 is connected to the pumping pipe 20 below the water surface of the groundwater 200 in the well 100. That is, the water treatment device 4 is immersed in the groundwater 200. In the flow path 2, the water treatment device 4 is provided on the secondary side of the submersible pump 3 in the pumping pipe 20.
The water treatment device 4 is installed in the pumping pipe 20 so that the groundwater 200 is treated while flowing substantially vertically upward (hereinafter, also referred to as "vertically connected" or "vertically installed"). When the water treatment device 4 is vertically installed in the pumping pipe 20 in this way, the water treatment direction and the power direction of the pumping water are in the same direction, so that the water treatment device 4 can be used evenly.
On the other hand, if the water treatment device is installed in the pumping pipe so that the groundwater is treated while flowing horizontally in the substantially horizontal direction, air tends to collect in the upper part of the water treatment device and it is difficult to maintain the liquidtightness. There is. Further, since the material is used in a biased state, there is a problem that it is liable to be locally deteriorated (especially when the water treatment device is a permeable membrane).

Examples of the water treatment device 4 include a filter, a pH adjuster, a filtration device, an ion exchange treatment device, and the like.
When a liquid (for example, sulfuric acid) is injected from the outside like a pH adjuster, it is preferable not to mix air in order to maintain the liquidtightness in the system.
Examples of the filtration device include those having one or both of the adsorption functional material and the filter material.
Examples of the adsorption functional material include activated carbon and an ion exchanger.
Examples of the filter medium include a filter containing at least one of a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and a reverse osmosis membrane.

When the groundwater 200 in the well 100 is provided below the water surface, it is preferable to use a filtration device containing only a filter medium as the water treatment device 4.
A filtration device containing only a filter medium has the advantage that when it is clogged with solids such as microorganisms and metal scales contained in the well, it can be operated continuously without frequent cleaning or replacement like an adsorption functional agent. .. In particular, if the water treatment device 4 is provided in the well 100, the workability of maintenance is inferior. Therefore, the number of maintenance can be significantly reduced by using the filtration device containing only the filter medium, and the water treatment system can be continuously operated for a long time. it can.

The gas supply means 5 includes a gas cylinder 51 filled with an inert gas having a specific gravity higher than that of air, and a gas supply pipe 52 whose tip is inserted into the well pipe 104 of the well 100 and whose base end is connected to the gas cylinder 51. It has a valve 53 provided in the middle of the gas supply pipe 52.

Examples of the inert gas having a higher specific gravity than air include argon, krypton, xenon, radon, oganeson and the like. As the inert gas having a specific gravity higher than that of air, one type may be used alone, or two or more types may be used in combination. As the inert gas having a higher specific gravity than air, argon alone is preferable because of its low cost and easy availability.
Nitrogen is known as an inert gas, but nitrogen has a lower specific gravity than air. Carbon dioxide is known as a gas having a higher specific gravity than air, but it is not classified as an inert gas because carbon dioxide dissolves in groundwater 200 and causes oxidation of metal ions.

The tip of the gas supply pipe 52 may be located near the ground in the well 100, may be near the water surface of the groundwater 200 in the well 100, and may be below the water surface of the groundwater 200 in the well 100. You may. Since the inert gas is a gas having a higher specific gravity than air, the inert gas tends to stay on the surface of the groundwater no matter where the inert gas is supplied in the well pipe 104 of the well 100.

(Mechanism of action)
In the water treatment system 1 described above, since the water treatment device 4 is provided on the secondary side of the submersible pump 3 in the pumping pipe 20 extending vertically and vertically, the groundwater 200 pumped by the submersible pump 3 Can be supplied from the water intake unit 2a to the water treatment device 4 while maintaining the liquidtightness. When the groundwater 200 is supplied from the water intake portion 2a to the water treatment device 4 while maintaining the liquidtightness, the water can be treated before the water quality of the groundwater 200 changes. As a result, the load on the water treatment device 4 is reduced, so that the maintenance frequency and the replacement frequency can be reduced. Further, it is not necessary to install the pretreatment device in the front stage of the water treatment device 4. Further, since the groundwater 200 is directly supplied from the water portion 2a to the water treatment device 4 by the submersible pump 3, it is not necessary to install the water conveyance pump in the front stage of the water treatment device 4. As a result, low cost and space saving can be realized. Further, when the groundwater 200 is directly supplied from the submersible pump 3 to the water treatment device 4, the liquidtightness from the water intake portion 2a can be maintained, so that the groundwater 200 can be prevented from coming into contact with the outside air and is included in the groundwater 200. It is possible to suppress metal oxidation and pipe clogging due to metal oxidation.
Further, in the water treatment system 1, in the pumping pipe 20 extending vertically and vertically, the water treatment device 4 is connected from the water intake portion 2a so as to maintain the liquidtightness, so that the water treatment is efficient. The device 4 can be operated. As a result, the maintenance frequency and replacement frequency of the water treatment device 4 can be reduced. Therefore, the water treatment system 1 can be continuously operated for a long time.
Further, in the water treatment system 1, since the water treatment device 4 is provided in the pumping pipe 20 constituting the flow path 2 in the well 100, it is not necessary to provide the water treatment equipment on the ground. This eliminates the need for equipment costs and installation space for water treatment equipment on the ground, so low cost and space saving can be realized.
Further, in the water treatment system 1, the water treatment device 4 is provided so as to maintain the liquidtightness from the water intake portion 2a in the pumping pipe 20 constituting the flow path 2 below the water surface of the groundwater 200 in the well 100. Is connected, so that the treated water is supplied to the flow path 2 on the secondary side of the water treatment device 4. By supplying the treated water to the secondary side of the water treatment device 4, the generation of iron scale in the pumping pipe 20 is suppressed for a long period of time. By suppressing the generation of iron scale in the groundwater 200 in the well 100 or in the flow path 2 such as the pumping pipe 20 for a long period of time, the frequency of maintenance of the water treatment system 1 can be sufficiently reduced.
Since the water treatment device 4 is connected to the pumping pipe 20, the pumping pipe 20 is loaded with the weight of the water treatment device 4, but the connecting portion of the water treatment device 4 is the groundwater 200 in the well 100. Since it is below the water surface, the load is reduced by buoyancy.

Further, in the water treatment system 1, a filtration device may be used as the water treatment device 4 vertically connected to the pumping pipe 20 constituting the flow path 2 below the water surface of the groundwater 200 in the well 100. preferable. Since the filtration device is immersed in the groundwater 200 in the well 100 together with the submersible pump 3, drying can be prevented even when the operation of the submersible pump 3 is stopped. In addition, the separated water from the filtration device can be returned to the water as it is.

Further, since the water treatment system 1 includes the gas supply means 5 for supplying the inert gas having a specific gravity higher than that of air into the well 100, the inert gas having a specific gravity higher than that of air is supplied into the well 100. Can be supplied to. When an inert gas having a specific gravity higher than that of air is supplied into the well 100, the inert gas stays on the surface of the groundwater 200 for a long time, and the inert gas layer is easily formed stably for a long time. Since the inert gas layer hinders the contact between the groundwater 200 and the air for a long time, the increase in the dissolved oxygen concentration in the groundwater 200 can be suppressed for a long period of time.
Further, in the water treatment system 1, since the inert gas supplied into the well 100 has a higher specific gravity than air, it is difficult to escape from the well 100. Therefore, the upper end of the well 100 can be opened, and it is not necessary to provide a sealing member such as a seal member at the upper end of the well 100, and it is not necessary to provide an air pressure adjusting mechanism for adjusting the air pressure in the well 100. Therefore, the consumption of the inert gas is suppressed, and the structure of the water treatment system 1 is not complicated. Therefore, it is possible to easily suppress an increase in the dissolved oxygen concentration in the groundwater 200 at low cost.
Then, in the water treatment system 1, the increase in the dissolved oxygen concentration in the groundwater 200 is suppressed for a long period of time, so that the iron scale is generated in the groundwater 200 in the well 100 and in the pumping pipe 20 and the like for a long time. It can be suppressed over a period of time. By suppressing the generation of iron scale in the groundwater 200 in the well 100, the pumping pipe 20 and the like for a long period of time, the frequency of maintenance of the water treatment system 1 can be sufficiently reduced.

(Other embodiments)
In the water treatment system of the present invention, a flow path having a region extending vertically and vertically in at least a part between an intake part and an outlet part, a pump connected to the water intake part, and a vertical direction up and down of the flow path. It is not limited to the water treatment system 1 shown in FIG. 1 as long as it is provided with a water treatment unit connected from the water intake unit so as to maintain liquidtightness in the region extending to the area.

For example, as shown in the water treatment system 61 shown in FIG. 2, above the water surface of the groundwater 200 in the well 100, the pumping pipe 20 constituting the flow path 2 is maintained to be liquidtight from the water intake portion 2a. May be connected.
In the water treatment system 61, since the water treatment device 4 is provided in the pumping pipe 20 constituting the flow path 2 in the well 100, the water treatment equipment is installed on the ground like the water treatment system 1 described above. There is no need to provide. This eliminates the need for equipment costs and installation space for water treatment equipment on the ground, so low cost and space saving can be realized.
Further, in the water treatment system 61, the water treatment device 4 is provided so as to maintain the liquidtightness from the water intake portion 2a in the pumping pipe 20 constituting the flow path 2 above the water surface of the groundwater 200 in the well 100. Can be treated before the water quality of the groundwater 200 changes. Further, the treated water is supplied to the flow path 2 on the secondary side of the water treatment device 4. By supplying the treated water to the flow path 2 on the secondary side of the water treatment device 4, the generation of iron scale in the pumping pipe 20 is suppressed for a long period of time. By suppressing the generation of iron scale in the groundwater 200 in the well 100 or in the flow path 2 such as the pumping pipe 20 for a long period of time, the frequency of maintenance of the water treatment system 61 can be sufficiently reduced.
Since the water treatment device 4 is connected to the pumping pipe 20 at a position separated from the submersible pump 3, the vibration of the submersible pump 3 is not easily transmitted to the water treatment device 4, and the operating state of the water treatment device 4 is stable. ..

Further, in the water treatment system 61, the water treatment is connected to the pumping pipe 20 constituting the flow path 2 above the water surface of the groundwater 200 in the well 100 so as to maintain the liquidtightness from the water intake portion 2a. As the device 4, it is preferable to use a filtration device containing only a filter medium. In this case, the number of maintenances is remarkably reduced, and the effect that the water treatment system can be operated for a long time can be obtained. In addition, the separated water from the filtration device can be returned to the inert gas atmosphere in the well 100. As a result, the generation of iron scale in the groundwater 200 in the well 100 and in the pumping pipe 20 and the like can be suppressed. By suppressing the generation of iron scale in the groundwater 200 in the well 100 and in the pumping pipe 20 and the like, the frequency of maintenance of the water treatment system 61 can be sufficiently reduced.

Further, as another embodiment, as shown in the water treatment system 71 shown in FIG. 3, a pumping pipe constituting the flow path 2 is formed outside the entrance of the well 100 (simply referred to as “outside the well 100”). It may be connected to 20 from the water intake portion 2a so as to maintain liquidtightness.
In the water treatment system 71, since the water treatment device 4 is provided in the pumping pipe 20 constituting the flow path 2 outside the well 100 (in other words, above the entrance of the well 100), the well 100 There is no need to install a separate water treatment facility outside the entrance (also called "well mass"). This eliminates the need for equipment costs and installation space for water treatment equipment, so low cost and space saving can be realized.
Further, in the water treatment system 71, since the water treatment device 4 is connected to the pumping pipe 20 extending vertically in the vertical direction from the water intake portion 2a so as to maintain the liquidtightness, the above-mentioned water treatment The water treatment device 4 can be operated as efficiently as the system 1. As a result, the maintenance frequency and replacement frequency of the water treatment device 4 can be reduced.
Since the water treatment device 4 is connected to the pumping pipe 20 outside the well 100, maintenance of the water treatment device 4 becomes easy. As a result, the work cost can be reduced.

Further, in the water treatment system 71, it is preferable to use a filtration device containing an adsorption functional material as the water treatment device 4 connected to the pumping pipe 20 outside the well 100. In this case, maintenance work such as cleaning and replacement of the adsorption functional material can be easily performed. In addition, impurities (for example, ammonia, etc.) that cannot be reliably removed only by the filter medium can be reliably removed by the adsorption functional material.

Further, as another embodiment, as shown in the water treatment system 81 shown in FIG. 4, the flow path 2 outside the entrance of the well 100 (outside the well 100) and extends vertically in the vertical direction. The water treatment device 4 may be connected to the water intake unit 2a so as to maintain the liquidtightness.
In the water treatment system 81, since the water treatment device 4 is provided in the flow path 2 other than the pumping pipe 20 outside the well 100, it is not necessary to separately provide the water treatment equipment. This eliminates the need for equipment costs and installation space for water treatment equipment, so low cost and space saving can be realized.
Further, in the water treatment system 81, the water treatment device 4 is connected from the water intake portion 2a to the region extending vertically and vertically in the flow path 2 so as to maintain the liquidtightness. The water treatment device 4 can be operated as efficiently as the water treatment system 1. As a result, the maintenance frequency and replacement frequency of the water treatment device 4 can be reduced.
Since the water treatment device 4 is connected to the flow path 2 other than the pumping pipe 20 on the outside of the well 100, the maintenance of the pumping pipe 20 and the water treatment device 4 becomes easy. As a result, the work cost can be reduced. Further, since the water treatment device 4 is connected to other than the pumping pipe 20, the load on the pumping pipe 20 due to the weight of the water treatment device 4 can be reduced. Further, since the water treatment device 4 can be connected to an arbitrary place outside the well 100, the degree of freedom in layout is high.

Further, in the water treatment system 81, it is preferable to use a filtration device containing an adsorption functional material as the water treatment device 4 connected to the flow path 2 outside the well 100. In this case, maintenance work such as cleaning and replacement of the adsorption functional material can be easily performed. In addition, impurities (for example, ammonia, etc.) that cannot be reliably removed only by the filter medium can be reliably removed by the adsorption functional material.

Further, although the water treatment system 1 shown in FIG. 1 includes a water treatment unit composed of one water treatment device 4, it may include two or more water treatment devices. Further, the two or more water treatment devices may be arranged in series with the flow path 2 and may be provided in a separated state.

Further, the water treatment system 1 shown in FIG. 1 is installed in a deep well that pumps up the groundwater 200 that springs from the pressure aquifer 204 below the unzoned aquifer 202, but because the groundwater is anaerobic, It may be installed in a shallow well that pumps groundwater from the non-pressure aquifer. Further, when the lift is low such as in a shallow well, a suction pump may be provided on the ground instead of the submersible pump.

<Water treatment method>
The water treatment method of the present invention (that is, the operation method of the water treatment system) is a method of generating treated water by treating the groundwater in the well with water, and directly supplies the groundwater pumped from the well to the water treatment unit. This is a method of treating groundwater before it changes in quality. The water treatment method of the present invention is particularly useful when there is no space for installing the water treatment equipment on the ground or when it is desired to reduce the cost of the water treatment equipment.
The water treatment method in the water treatment system 1 of the illustrated example is as follows, for example.

The valve 53 of the gas supply means 5 is opened to supply an inert gas having a specific gravity higher than that of air into the well pipe 104 of the well 100. When the oxygen concentration in the atmosphere in the well pipe 104 becomes equal to or lower than the preset initial value, the valve 53 is closed and the supply of the inert gas having a specific gravity higher than that of air is stopped.

The submersible pump 3 is operated, the groundwater 200 is taken from the water intake portion 2a of the flow path 2, the groundwater 200 is pumped up by the submersible pump 3, and is introduced into the water treatment device 4 via the pumping pipe 20. The groundwater treated by the water treatment device 4 is supplied to the outlet portion 2b of the flow path 2 via the pumping pipe 20 and the headrace pipe 22, and then supplied to the outside as domestic water, industrial water, agricultural water, and the like. ..
The separated water led out from the water treatment device 4 may be returned to the well water 100 in the well pipe 104, or may be discharged to the outside of the well pipe 104.
The submersible pump 3 operates continuously or intermittently depending on the treatment frequency and the amount of groundwater treated in the water treatment device 3 at the subsequent stage.

The oxygen concentration in the atmosphere in the well pipe 104 is periodically measured, and when the oxygen concentration in the atmosphere exceeds a preset upper limit value, the valve 53 of the gas supply means 5 is opened, and the specific gravity is higher than that of air. It is preferable to supply the active gas into the well pipe 104 of the well 100 until the oxygen concentration in the atmosphere in the well pipe 104 becomes equal to or less than a preset initial value.

The frequency of supply of the inert gas, which has a higher specific gravity than air, is preferably once a week or more, more preferably once a month or more, further preferably once every one to three months, and three months to twelve. Especially once a month. If the frequency of supply of the inert gas having a specific gravity higher than that of air is equal to or higher than the lower limit, the increase in the dissolved oxygen concentration in the groundwater can be suppressed more easily at a lower cost. If the frequency of supply of the inert gas having a specific gravity higher than that of air is not more than the upper limit, the increase in the dissolved oxygen concentration in the groundwater can be further suppressed.

Groundwater usually contains iron-oxidizing bacteria (iron bacteria), dissolved oxygen, divalent iron ions, organic matter, ammonia, methane and the like. The dissolved oxygen concentration in groundwater is preferably 1 mg / L or less, more preferably 0.5 mg / L or less, from the viewpoint of sufficiently suppressing the generation of iron scale. The pH of groundwater is preferably 6 or less from the viewpoint of suppressing the oxidation of divalent iron ions and the growth of iron bacteria. The pH of the groundwater is preferably 5 or more from the viewpoint of the water quality of the groundwater. In order to keep the pH of the groundwater within the above range, a pH adjuster addition means may be further provided in the water treatment system 1 to add the pH adjuster to the groundwater.

(Mechanism of action)
In the water treatment method of the present invention described above, the water treatment system 1 of the present invention is used, and the groundwater 200 pumped from the well 100 by the submersible pump 3 is installed in the well 100 (water treatment). Part) Since it is directly supplied to 4 and treated before the quality of groundwater changes, it is not necessary to separately install a water treatment facility on the ground. Therefore, the cost and space for installing the water treatment facility on the ground can be suppressed.
Further, in the water treatment method of the present invention, since the water treatment device 4 connected to the pumping pipe 20 extending vertically in the vertical direction so as to maintain the liquidtightness from the water intake portion 2a is used, it is efficient. Can treat groundwater. As a result, the maintenance frequency and replacement frequency of the water treatment device 4 can be sufficiently reduced.

(Other embodiments)
The water treatment method of the present invention may be any method as long as the groundwater pumped from the well is directly supplied to the water treatment unit and treated before the quality of the groundwater changes, and when the water treatment system 1 of FIG. 1 is used. Not limited. For example, as shown in FIGS. 2 to 4, a flow path having a region extending vertically and vertically in at least a part between the water intake part and the outlet part, a pump connected to the water intake part, and a flow path of the flow path. It may be a water treatment method using a water treatment system provided with a water treatment unit connected from the water intake unit so as to maintain liquidtightness in a region extending vertically in the vertical direction.

The present invention is particularly useful as a water treatment system when there is no space for installing the water treatment equipment on the ground or when it is desired to reduce the cost of the water treatment equipment.

1,61,71,81 Water treatment system,
2 channels,
2a Water intake,
2b exit,
3 Submersible pump (pump),
4 Water treatment equipment (water treatment unit)
5 Gas supply means,
20 pumping pipe,
22 Water pipe,
51 gas cylinder,
52 gas supply pipe,
53 valves,
100 wells,
102 drilling hole,
104 well pipe,
104a Intake,
200 groundwater,
202 Aquifer,
204 Pressure aquifer.

Claims (12)

A water treatment system that produces treated water from groundwater in a well.
A flow path having a groundwater intake portion, an outlet portion for discharging treated water to the outside of the well, and a region extending vertically up and down at least a part between the intake portion and the outlet portion.
A pump connected to the intake portion of the flow path and introducing the groundwater into the flow path.
A water treatment system comprising a water treatment unit connected to the region of the flow path so as to maintain liquidtightness from the water intake unit. The water treatment system according to claim 1, further comprising a gas supply means for supplying an inert gas having a specific gravity higher than that of air into the well. The water treatment system according to claim 1 or 2, wherein the water treatment unit is installed so that the groundwater is treated while flowing substantially vertically upward. The water treatment system according to any one of claims 1 to 3, wherein the water treatment unit is located in a well. The water treatment system according to any one of claims 1 to 4, wherein the water treatment unit is located below the surface of the groundwater in the well. The water treatment system according to any one of claims 1 to 3, wherein the water treatment unit is located outside the entrance of the well. The water treatment system according to claim 4 or 5, wherein the water treatment unit contains only a filter medium. The water treatment system according to claim 6, wherein the water treatment unit includes a filtration device having an adsorption functional material and a filter medium. The water treatment system according to claim 7 or 8, wherein the filter medium contains at least one of a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, and a reverse osmosis membrane. The water treatment system according to any one of claims 1 to 9, wherein the flow path includes a pumping pipe inserted into a well. The water treatment system according to claim 10, wherein the pumping pipe extends outside the entrance of the well. The water treatment system according to claim 10 or 11, wherein the region is the pumping pipe.

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