JP7099670B2 - Optical brightener fading system - Google Patents

Description

The present invention relates to a fluorescent dye fading system.

For the purpose of purifying contaminated ground, ground improvement, heat storage, water shielding, etc., an injection liquid containing an injection agent such as a purifying agent, an activator, or a supercooled aqueous solution may be injected into the ground. In addition, for the purpose of groundwater flow survey, etc., an injection liquid to which an injection agent is not added may be injected into the ground.

Here, in order for the injection agent added to the injection liquid to function effectively when purifying the contaminated ground, it is necessary to appropriately control the concentration of the injection agent in the groundwater. However, in order to measure the concentration of the injectant in the groundwater, it may be necessary to bring the collected groundwater to a test room and measure it with a large-scale facility, which is troublesome. In addition, there are cases where the measurement itself is difficult due to the low concentration of the injection agent, or even if the measurement is possible, it is difficult to determine whether or not the injection agent has arrived due to the dissolution or dispersion of the injection agent.

In order to solve this problem, for example, a method of estimating the concentration of the injection agent by adding an amount of fluorescent dye corresponding to the amount of the injection agent to the injection liquid and measuring the concentration of the fluorescent dye in the ground water in the in-situ is known. Has been done. Further, there is known a method of observing the groundwater flow in the ground by adding a fluorescent dye to the injection liquid as a tracer and measuring the concentration of the fluorescent dye in the groundwater at the time of groundwater flow survey or the like.

As an example, in Patent Document 1, an injection liquid to which an injection agent and a fluorescent dye (index agent) are added is injected into the ground from a water injection well (water injection means), and groundwater is pumped by a pumping well (pumping means). A ground injection concentration estimation system that returns to a water injection well is disclosed.

International Publication No. 2018/08996

In the ground injection agent concentration estimation system shown in Patent Document 1, an amount of fluorescent dye (index agent) corresponding to the amount of injection agent is added to the injection liquid, and the concentration of the fluorescent dye (index agent) in groundwater is measured. By doing so, the concentration of the injection agent is estimated and the concentration of the injection agent in the groundwater is controlled.

Generally, groundwater colored by a fluorescent dye is pumped and then returned to a water injection means, or drained to the outside such as a sewer. However, when the colored groundwater is refluxed to the water injection means, it is difficult to control the fluorescent dye to the target concentration in the injection liquid. In addition, when draining colored groundwater to the outside such as sewerage, there is a possibility of violating the drainage regulations set by some municipalities, and it was difficult to drain.

In view of the above facts, an object of the present invention is to provide a fluorescent dye fading system capable of fading a fluorescent dye contained in pumped groundwater.

The fluorescent dye fading system according to the first aspect is a water injection means for injecting an injection liquid to which a fluorescent dye is added into the ground, and a concentration for measuring the concentration of the fluorescent dye in the ground at a place away from the water injection means. It has a measuring device, a pumping means for pumping groundwater, and a fading device for fading the fluorescent dye contained in the groundwater pumped from the pumping means.

According to the above configuration, by injecting the injection liquid into the ground from the water injection means, it is possible to investigate the flow of groundwater, purify the contaminated ground, improve the ground, store heat, impermeable water, and the like. In addition, since the fluorescent dye is added to the injection liquid, the concentration of the fluorescent dye in the ground can be measured with a concentration measuring device at a place away from the water injection means to observe the groundwater flow and the concentration of the injection agent. Can be estimated.

Further, by fading the fluorescent dye contained in the groundwater pumped from the pumping means by the fading device, it is possible to suppress the flow of the groundwater containing the fluorescent dye to the outside or the like.

The fluorescent dye fading system according to the second aspect is the fluorescent dye fading system according to the first aspect, in which an injection agent is added to the injection liquid, and the fluorescent dye is the injection agent in the ground. It is said to be a substance that exhibits the same behavior as.

According to the above configuration, the injection liquid to which the injection agent is added is injected from the water injection means into the ground and pumped by the pumping means to create a groundwater flow between the water injection means and the pumping means, and the injection liquid contaminates the groundwater, for example. The ground can be purified.

In addition, since the fluorescent dye is considered to be a substance that behaves in the ground in the same manner as the injection agent, the concentration of the fluorescent dye in the ground is measured by the first concentration measuring device at a place away from the water injection means. It is possible to estimate the concentration of the injection agent and control the concentration of the injection agent at a predetermined position in the ground.

The fluorescent dye fading system according to the third aspect is the fluorescent dye fading system according to the first or second aspect, and the fading device is an ultraviolet irradiation device that irradiates the ground water with ultraviolet rays.

According to the above configuration, by irradiating the groundwater with ultraviolet rays by an ultraviolet irradiation device as a fading device, the color-developing groups of the fluorescent dye contained in the groundwater can be decomposed and faded.

The fluorescent dye fading system according to the fourth aspect is the fluorescent dye fading system according to any one of the first to third aspects, and the groundwater pumped from the water pumping means is returned to the water injection means. It has a recirculation path and a water treatment device provided in the recirculation path to treat the groundwater pumped from the pumping means, and the fading device is provided in the recirculation path.

According to the above configuration, the groundwater pumped from the pumping means is treated by the water treatment device and returned to the water injection means by the reflux route, so that the groundwater can be used as the injection liquid. Here, since the fading device is provided in the reflux path, the fluorescent dye contained in the ground water can be faded once, and then the fluorescent dye can be added again to generate the injection liquid, and the fluorescent dye can be produced in the injection liquid. It can be controlled to the target concentration.

The fluorescent dye fading system according to the fifth aspect is the fluorescent dye fading system according to the fourth aspect, and is a drainage system for draining a part of the groundwater pumped from the pumping means to the outside from the recirculation route. The route is branched, and the fading device is provided on the upstream side of the branch point of the drainage route.

According to the above configuration, since the fading device is provided on the upstream side of the drainage path branching from the return path, it is possible to prevent the groundwater colored with the fluorescent dye from being drained to the outside through the drainage path. can.

According to the fluorescent dye fading system according to the present invention, the fluorescent dye contained in the pumped groundwater can be faded.

It is a top view which shows the schematic structure of the fluorescent dye fading system which concerns on 1st and 2nd Embodiment. It is a vertical sectional view which shows the schematic structure of the fluorescent dye fading system which concerns on 1st and 2nd Embodiment. It is a graph which shows the relationship between the light intensity and the wavelength of the excitation light and fluorescence in the fluorescent dye fading system which concerns on 1st Embodiment.

Hereinafter, the fluorescent dye fading system according to the first and second embodiments of the present invention will be described with reference to FIGS. 1 to 3. The description of common components represented by the same reference numerals in a plurality of drawings may be omitted.

[First Embodiment]
(overall structure)
As shown in FIGS. 1 and 2, the fluorescent dye fading system 10 of the present embodiment has a pumping well 14 (14A, 14B) as a pumping means constructed in an underground ground 12 and a water injection well 16 (14A, 14B) as a water injection means. It has 16A, 16B), an observation well 18 (18A-18C), and an impermeable wall 20.

Further, above the ground surface GL, there is a concentration measuring device 22 for measuring the concentration of the fluorescent dye in the groundwater collected from the observation well 18, and a recirculation path 30 for returning the groundwater pumped from the pumping well 14 to the water injection well 16. And are built. Further, the reflux path 30 is provided with an ultraviolet irradiation device 32 as a fading device and a purification device 24.

(Underground ground)
The underground ground 12 is a ground below the ground surface GL, and has an aquifer 26 through which groundwater flows and an impermeable layer 28 through which groundwater does not flow, as shown in FIG. The portion of the underground ground 12 containing a reference value (for example, a value determined for each type of pollutant) or more is referred to as contaminated ground E.

"Contaminants" include organic substances such as tetrachlorethylene, trichlorethylene, cis-1,2-dichloroethylene, vinyl chloride monomer and benzene, inorganic compounds such as hexavalent chromium and cyanide, and oils such as mineral oils such as gasoline and light oil. It is a concept that includes.

In FIG. 2, the groundwater level HL is illustrated by a chain line, and the direction of the groundwater flow in the underground ground 12 is indicated by a broken line arrow. This groundwater flow is a flow generated by injecting an injection liquid containing an injection agent or the like, which will be described later, from the water injection well 16 into the underground ground 12, and further pumping the groundwater from the pumping well 14.

(Pump well)
The pumping well 14 is a pumping means for pumping groundwater from the underground ground 12, and can suck up the groundwater in the aquifer 26 by the pumping pump P and send it to the purification device 24.

In FIGS. 1 and 2, the pumping pump P is installed outside the pumping well 14, but this is for the purpose of explaining the configuration, and it is assumed that the pumping pump P is installed inside the pumping well 14. .. However, the pump P may be installed outside the pumping well 14. Further, the pumping well 14 is arranged between the contaminated ground E and the impermeable wall 20, and is buried in the underground ground 12 so that the depth at the lower end is equal to or less than the depth of the contaminated ground E.

In FIG. 1, for convenience of illustration, only two pumping wells 14A and 14B are shown, but the embodiment of the present invention is not limited to this, and any number of pumping wells 14 can be provided according to the size of the site and the like. It may be arranged as appropriate.

The pumping well 14 may be arranged on the contaminated ground E. Further, since the specific method of pumping by the pumping well 14, the shape and size of the pumping well 14, and the like are known, detailed description thereof will be omitted.

(Water injection well)
The water injection well 16 is a water injection means for injecting the injection liquid generated by the purification device 24 into the underground ground 12, and the injection liquid can be sent into the underground ground 12 by a pump or the like (not shown). Further, the water injection well 16 is a well arranged between the contaminated ground E and the impermeable wall 20 (opposite the pumping well 14 when viewed from the contaminated ground E), and the depth at the lower end is equal to or less than the depth of the contaminated ground E. It is buried in the underground ground 12 so as to be.

In FIG. 1, for convenience of illustration, only two water injection wells 16A and 16B are shown, but the embodiment of the present invention is not limited to this, and any number of water injection wells 16 can be provided according to the size of the site and the like. It may be arranged as appropriate.

The water injection well 16 may be arranged in the contaminated ground E. Further, since the specific method of injecting the injection liquid by the water injection well 16 and the shape, size, etc. of the water injection well 16 are known, detailed description thereof will be omitted.

(Observation well)
The observation well 18 is an observation means for observing an underground state, and is provided between the water injection well 16 and the pumping well 14 at a predetermined distance from the water injection well 16 and the pumping well 14. Here, the "underground state" indicates a state in the underground ground 12 at the position where the observation well 18 is buried, for example, the groundwater level, the ground temperature, the injection agent concentration and the fluorescent dye concentration in the groundwater, which will be described later. , Contaminant concentration in groundwater, etc.

Various sensors (not shown) are installed in the observation well 18, and these sensors measure the above-mentioned groundwater level, ground temperature, fluorescent dye concentration in groundwater, and the like, and these measured values are described later in the purification device 24. It is transmitted to the control device 38 of the above by an electric signal.

These sensors are also installed inside the pumping well 14 and the water injection well 16. That is, the pumping well 14 and the water injection well 16 also function as observation means, respectively. Further, in FIGS. 1 and 2, the signal line connected to the control device 38 is not shown in order to avoid complicating the figure.

In addition, a pumping pump (not shown) is installed inside or outside the observation well 18, to collect groundwater at a predetermined depth of the observation well 18 and pump the collected groundwater to the concentration measuring device 22 installed on the ground. Can be done.

The observation wells 18 are buried at a plurality of locations in the underground ground 12 surrounded by the impermeable wall 20, and in FIG. 1, only three observation wells 18A, 18B, and 18C are shown for convenience of illustration. There is. However, the embodiment of the present invention is not limited to this, and an arbitrary number of observation wells 18 may be appropriately arranged according to the size of the site and the like.

(Immersion wall)
The impermeable wall 20 is an impermeable means of a steel sheet pile (sheet pile) arranged in the underground ground 12 so as to surround the periphery of the contaminated ground E, and blocks the flow of groundwater inside and outside the impermeable wall 20. .. That is, the flow of groundwater in the underground ground 12 "outside" of the impermeable wall 20 and the flow of groundwater in the underground ground 12 "inside" the impermeable wall 20 are prevented from affecting each other.

As shown in FIG. 2, the lower end of the impermeable wall 20 is embedded in the impermeable layer 28. As a result, the contaminated ground E is surrounded by the impermeable wall 20 and the impermeable layer 28, and the outflow of the contaminated material to the underground ground 12 outside the impermeable wall 20 is suppressed.

(Purification device)
The purification device 24 is a device for purifying the groundwater pumped from the pumping well 14, adding an injection agent or the like described later, and returning the groundwater to the underground ground 12, and is a water treatment device 34, an addition tank 36, and a control device 38. Consists of including.

(Water treatment equipment)
The water treatment device 34 separates (and extracts) volatile pollutants and oils from the groundwater pumped from the pumping well 14. Further, the water treatment device 34 heats the purified groundwater by a heater (not shown) whose temperature is controlled by the control device 38 described later. By heating the groundwater with the water treatment device 34, it is possible to promote the growth of the degrading microorganisms that biodegrade the pollutants in the underground ground 12 and to increase the activity of the degrading microorganisms.

(Addition tank)
The addition tank 36 adds at least one of a purifying agent or an activator as an injection agent and a fluorescent dye to the groundwater to generate an injection liquid. Specifically, at least one of the purifying agent or the activator and the fluorescent dye are added to the groundwater inside the addition tank 36 from a charging device (not shown) controlled by the control device 38 described later, and the mixture is stirred and injected. An injection liquid to be injected from the well 16 into the underground ground 12 is generated.

Here, the "purifying agent" is a substance that decomposes a pollutant in the underground ground 12, and as an example, "degrading microorganisms" such as dehalococcoides and dehalosulfide that biodegrade the pollutant. , There are "chemical decomposition agents" that chemically decompose pollutants. Specific examples of the chemical decomposition agent include "reducing agents" such as iron-based slurrys and "oxidizing agents" such as hydrogen peroxide, sulfates, Fenton's reagents, permanganic acid, and percarbonates.

The "activator" is a substance that activates the biodegradation of degrading microorganisms, and a hydrogen sustained-release agent, an organic substance, a pH adjuster, a micronutrient, a trace element, or the like can be used.

Of these, organic substances include formic acid, acetic acid, propionic acid, butyric acid, lactic acid or citric acid or their sodium salts, potassium salts or calcium salts, glucose, fructose, galactose, lactose, maltose, trehalose, peptone, tripton, yeast extract. , Fumic acid, vegetable oil and the like can be used.

As the pH adjuster, sodium hydrogen carbonate, sodium such as sodium carbonate, potassium carbonate, hydrogen carbonate, ammonium hydroxide, ammonium carbonate, sodium tripolyphosphate, disodium hydrogen phosphate, trisodium phosphate and the like can be used. Can be used.

Further, as the micronutrient, vitamin B12, vitamin B1, pantothenic acid, biotin, folic acid and the like can be used. Further, as the trace element, Co, Zn, Fe, Mg, Ni, Mo, B and the like can be used. In this embodiment, an activator (yeast extract) is used as an injection agent.

The fluorescent dye is a substance that behaves like a purifying agent or an activator in the underground ground 12 (including the contaminated ground E), and is in the in-situ (contaminated ground) even in a low concentration state without using a large-scale facility. It is a substance whose concentration can be easily measured on E or in a nearby building.

As the fluorescent dye, uranin, eosin, rhodamine B, rhodamine WT, pyranine, amino G acid, sodium naphthoate, sulfordamine G and the like can be used, but in this embodiment, eosin is used.

Here, "having the same behavior as a purifying agent or an activator" specifically means that the density, viscosity, adsorption / decomposition characteristics, etc. of the fluorescent dye with respect to groundwater are similar to those of the purifying agent or the activator. .. The adsorption / decomposition characteristics of the fluorescent dye and the adsorption / decomposition characteristics of the purifying agent or the activator may have a difference to the extent that the above-mentioned coefficient α can be calculated. Further, "similarity" includes not only the case of perfect agreement but also the degree of slight difference that can be measured by the test.

The fluorescent dye is used as a substance (tracer) for measuring the concentration of the purifying agent or the activator in the groundwater of the underground ground 12. By measuring the concentration of the fluorescent dye, the concentration of the purifying agent or the activator in the groundwater of the underground ground 12 can be estimated.

(Ultraviolet irradiation device)
An ultraviolet irradiation device 32 is provided on the upstream side of the purification device 24 in the return path 30, that is, between the pumping well 14 and the purification device 24. The ultraviolet irradiation device 32 is an example of a fading device for fading the fluorescent dye contained in the groundwater pumped from the pumping well 14, for example, in an ultraviolet irradiation tank (not shown) connected to the return path 30 and an ultraviolet irradiation tank. It is equipped with an installed UV lamp (not shown).

(Concentration measuring device)
The groundwater inside the observation wells 18 (18A, 18B, 18C) is pumped to a predetermined depth by a pump (not shown) installed inside each well and sent to the concentration measuring device 22 via a header (not shown). ..

The header is a collective piping member for combining multiple pipes into one, and which of the groundwater pumped from the three observation wells 18A, 18B, and 18C can be opened and closed by opening and closing solenoid valves and valves (not shown). It is possible to select whether to send the groundwater to the concentration measuring device 22.

The concentration measuring device 22 can measure the intensity of the light emitted by the fluorescent dye contained in the groundwater sent from the header. Specifically, for example, groundwater is irradiated with excitation light from a light source device (not shown), and the light intensity C of fluorescence generated from the fluorescent dye contained in the groundwater is measured by a spectroscope (not shown). As a specific example, FIG. 3 shows the respective light intensities of the excitation light wavelength L1 and the fluorescence wavelength L2.

The concentration of the fluorescent dye can be calculated from this light intensity C, but if the concentration of this fluorescent dye is expressed as F (C) as a function of the light intensity C, the activator (yeast extract) as an injection agent is estimated. The density X can be expressed as follows. The coefficient α is derived from the difference in adsorption / decomposition characteristics measured by carrying out the adsorption / decomposition tests of the activator (yeast extract) and the fluorescent dye, respectively.

(Estimated concentration X of activator) = α × [Concentration F (C) of fluorescent dye] ... (1 formula)
α: coefficient

Further, as shown in FIG. 2, an ultraviolet irradiation device 40 as a fading device is provided downstream of the density measuring device 22. In the present embodiment, the ultraviolet irradiation device 40 has the same configuration as the ultraviolet irradiation device 32 provided in the return path 30, and the colored groundwater pumped from the observation well 18 is collected by the ultraviolet irradiation device 40. After fading, it is drained to the outside such as sewerage.

(Control device)
The control device 38 is used for information such as groundwater level and ground temperature measured by sensors (not shown) installed in the observation well 18, the water injection well 16, and the pumping well 14, and in the groundwater measured by the concentration measuring device 22. Information such as the concentration of fluorescent dye is received as an electric signal. Then, the water treatment device 34, the addition tank 36, and the pump P are driven and controlled according to the received information.

(Method for estimating the concentration of injection agent)
In the fluorescent dye fading system 10 of the present embodiment, as shown in FIG. 2, first, in the addition tank 36, an activator (yeast extract) as an injection agent is added to the injection liquid to be injected from the water injection well 16 into the underground ground 12. Fluorescent dye (eosin) is added. Here, the concentration of the activator (yeast extract) in the injection solution is made equal to the concentration of the fluorescent dye. That is, the relationship between the respective concentrations in the injection solution is expressed as follows.

(Concentration of activator): (Concentration of fluorescent dye) = 1: 1 ... (2 formulas)

Next, the injection liquid to which the activator (yeast extract) and the fluorescent dye (eosin) are added is injected from the addition tank 36 into the water injection well 16. In the injection liquid injected into the water injection well 16, the pump P pumps groundwater from the pumping well 14 to generate a water gradient of the groundwater, so that the water injection well 16 to the underground ground 12 and the contaminated ground E at a target speed. Spread to.

At this time, since the activator (yeast extract) and the fluorescent dye (eosin) have the same density, viscosity, adsorption / decomposition characteristics, etc. with respect to groundwater, they diffuse at almost the same speed. However, since the activator (yeast extract) and the fluorescent dye (eosin) have a slight difference in adsorption / decomposition characteristics, a difference in concentration in groundwater occurs in the process of diffusing into the underground ground 12. Therefore, the relationship between the respective concentrations in groundwater is estimated as follows using the coefficient α according to the adsorption / decomposition characteristics.

(Estimated concentration of activator): (Concentration of fluorescent dye) = α: 1 ... (3 formulas)

Next, at a place away from the water injection well 16, the groundwater inside the observation well 18 is collected by a pump (not shown) provided inside the observation well 18 and sent to the concentration measuring device 22. The light intensity C of the fluorescent dye (eosin) is measured by the density measuring device 22, and the concentration F (C) of the fluorescent dye (eosin) is calculated.

Here, when the estimated concentration X of the activator (yeast extract) and the concentration F (C) of the fluorescent dye (eosin) are substituted on the left side of (Equation 3), it is expressed as follows.

(Estimated concentration X of activator): [Concentration F (C) of fluorescent dye] = α: 1 ... (4 formulas)

By modifying this (4 formulas), the above-mentioned (1 formula) can be obtained, and the estimated concentration X of the activator (yeast extract) at a predetermined position in the underground ground 12 can be calculated. The amount of the injection liquid injected into the water injection well 16 is controlled by the control device 38 based on the estimated concentration X of the activator (yeast extract).

(How to fade fluorescent dye)
Further, the groundwater in the underground ground 12 is pumped from the pumping well 14 by the pump P and sent to the ultraviolet irradiation tank of the ultraviolet irradiation device 32 through the return path 30. At this time, the recirculated groundwater may be colored by the fluorescent dye.

By irradiating the groundwater with ultraviolet rays by an ultraviolet lamp in the ultraviolet irradiation tank of the ultraviolet irradiation device 32, the coloring group of the fluorescent dye contained in the groundwater can be decomposed and the color of the groundwater can be erased. The groundwater whose color has been erased is returned from the ultraviolet irradiation tank to the reflux path 30 and treated by the water treatment device 34 of the purification device 24, and the activator (yeast extract) and the fluorescent dye (eosin) are again used in the addition tank 36. ) Is added and used as an injection solution.

(Action / effect)
According to the present embodiment, the injection liquid to which the activator (yeast extract) as an injection agent is added is injected from the water injection well 16 into the underground ground 12 and pumped by the pumping well 14, so that the water injection well 16 and the pumping well are pumped. A groundwater flow can be created between 14 and 14, and the biodegradation of degrading microorganisms can be activated by an activator (yeast extract) to promote purification of contaminated ground E.

In addition, a fluorescent dye (eosin) is added to the injection solution together with the injection agent (activator). Therefore, the concentration of the injection agent is estimated by measuring the concentration of the fluorescent dye in the underground ground 12 with the concentration measuring device 22 at a place away from the water injection well 16, and the injection is performed at a predetermined position in the underground ground 12. The concentration of the agent can be controlled.

Further, according to the present embodiment, the groundwater pumped from the pumping well 14 is treated by the water treatment device 34 and returned to the water injection well 16 by the return path 30, so that the groundwater can be used as an injection liquid.

Here, the ultraviolet irradiation device 32 is provided in the reflux path 30. Therefore, by irradiating the groundwater pumped from the pumping well 14 with ultraviolet rays by the ultraviolet irradiation device 32, the color-developing group of the fluorescent dye contained in the groundwater can be decomposed and faded. As a result, the fluorescent dye can be controlled to the target concentration in the injection liquid by adding the injection agent and the fluorescent dye again in the addition tank 36 of the purification device 24 to generate the injection liquid.

In the present embodiment, the "target concentration" of the fluorescent dye refers to the concentration of the fluorescent dye with respect to the concentration of the injection agent, and is equal to the concentration of the activator (yeast extract) as represented by (Equation 3). Has been done. However, the target concentration of the fluorescent dye with respect to the concentration of the injection agent can be appropriately set according to the injection agent used, the type of the fluorescent dye, and the adsorption / decomposition characteristics, and may be changed during the purification work of the contaminated ground E. It is possible.

For example, when the ratio of the concentration of the activator (yeast extract) to the concentration of the fluorescent dye in the injection solution is (a: 1), the activator (yeast extract) is estimated by multiplying the right side of (1 formula) by a. The concentration is calculated. This value of a is arbitrary, but since the fluorescent dye is not expected to have a pollutant decomposition effect, the fluorescent dye may be contained in an amount necessary for calculating the concentration of the activator (yeast extract), for example. It may be about a = 60.

[Second Embodiment]
In the first embodiment, all the groundwater pumped from the pumping well 14 was returned to the water injection well 16 via the return path 30, but in the second embodiment, one of the groundwater pumped from the pumping well 14 The part is drained to the outside such as the sewer.

Specifically, as shown in FIGS. 1 and 2, in the present embodiment, the drainage route 42 branches from the reflux route 30. The drainage route 42 is a route for draining a part of the groundwater pumped from the pumping well 14 to the outside of the fluorescent dye fading system 10. A switching valve 44 for switching between the two is provided.

Here, the branch point between the reflux path 30 and the drainage path 42 is provided on the downstream side of the ultraviolet irradiation device 32. In other words, the ultraviolet irradiation device 32 is provided on the upstream side (pumping well 14 side) of the switching valve 44.

According to the present embodiment, since the drainage path 42 branches from the return path 30, a part of the groundwater pumped from the pumping well 14 can be drained to the outside through the drainage path 42. Thereby, for example, when the amount of groundwater pumped from the pumping well 14 is larger than the amount of the injection liquid injected into the water injection well 16, the amount of groundwater returned to the water injection well 16 can be adjusted.

Further, an ultraviolet irradiation device 32 is provided on the upstream side of the branch point between the reflux path 30 and the drainage path 42. Therefore, the fluorescent dye contained in the groundwater can be faded by the ultraviolet irradiation device 32 and then flowed to the drainage path 42, and the groundwater with the tint of the fluorescent dye is drained to the outside through the drainage path 42. It can be suppressed.

In this embodiment, a part of the groundwater pumped from the pumping well 14 is drained to the outside through the drainage route 42. However, the embodiment of the present invention is not limited to this, and the groundwater pumped from the pumping well 14 may not be returned to the water injection well 16 but may be drained to the outside through the drainage route 42.

[Other embodiments]
Although the first and second embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. In addition, the configurations of the above embodiments can be combined as appropriate.

For example, in the first and second embodiments, the contaminated ground E of the one aquifer 26 formed above the impermeable layer 28 of the underground ground 12 is purified, but a plurality of layers divided by the impermeable layer are purified. It may be configured to purify the contaminated ground of the aquifer.

When purifying the contaminated ground of a plurality of aquifers, the pumping well 14, the water injection well 16, the observation well 18, the concentration measuring device 22, the ultraviolet irradiation device 32, 40, and the purification device 24 shown in FIGS. 1 and 2, respectively. Can be purified in each aquifer by installing each in the aquifer.

Here, when purifying a plurality of aquifers divided by an impermeable layer, a fluorescent dye flows out from one aquifer to the other aquifer, and a plurality of types of fluorescent dyes are mixed in the aquifer. May be done. Therefore, it is preferable to use a fluorescent dye added to the injection liquid to be injected into the aquifer so that the band of the excitation light wavelength L1 and the band of the fluorescence wavelength L2 are sufficiently separated.

As a result, the concentration of the injection agent can be estimated by measuring the concentration of the plurality of fluorescent dyes of different types by the concentration measuring device 22, and the concentration of the injection agent can be controlled at a predetermined position in the ground. can.

When the thickness of the impermeable layer that divides the aquifer is sufficiently large and there are no cracks, the same type of fluorescent dye may be used for the injection liquid to be injected into the aquifer of a plurality of layers. Even if the same type of fluorescent dye is used, it is unlikely that these fluorescent dyes are mixed, so that the concentration of each fluorescent dye can be measured. Further, the control device of the purification device and the ultraviolet irradiation device (fading device) installed in the aquifer may be combined into one.

Further, in the first and second embodiments, the ultraviolet irradiation devices 32 and 40 have an ultraviolet irradiation tank, but the embodiment of the present invention is not limited to this. For example, the return path 30 may be composed of a translucent pipe, and the groundwater may be irradiated with ultraviolet rays by an ultraviolet lamp arranged around the pipe. An opening is provided in the upper part of the return path 30 and the ultraviolet rays pass through the opening. The upper surface of the groundwater may be irradiated with ultraviolet rays by a lamp. In addition, known ultraviolet irradiation devices can be used as the ultraviolet irradiation devices 32 and 40.

Further, in the first and second embodiments, the ultraviolet irradiation devices 32 and 40 are used as an example of the fading device, but the fading device may have a configuration capable of fading the fluorescent dye contained in the groundwater. .. For example, as the fading device, a sunlight exposure device that exposes the groundwater to sunlight may be used, or a drug addition device that adds a chemical such as hypochlorous acid to the groundwater may be used.

Further, the fading device (ultraviolet irradiation device 32) provided in the reflux path 30 and the fading device (ultraviolet irradiation device 40) provided downstream of the concentration measuring device 22 had the same configuration, but they were different from each other. A fading device may be provided.

Further, for example, as shown by the arrow 46 of the alternate long and short dash line in FIG. 2, the colored groundwater pumped from the observation well 18 is faded by the ultraviolet irradiation device 32 without being drained to the outside such as the sewer. After that, it may be configured to return to the water injection well 16.

Further, in the first embodiment, the fading device (ultraviolet irradiation device 32) is provided on the upstream side (pumping well 14 side) of the water treatment device 34 in the purification device 24. However, the fading device may be provided at least on the upstream side (pumping well 14 side) of the addition tank 36, and may be provided, for example, on the downstream side (water injection well 16 side) of the water treatment device 34.

By providing the fading device on the downstream side of the water treatment device 34, for example, when a sunlight exposure device is used as the fading device, the groundwater treated by the water treatment device 34 can be exposed to sunlight. As a result, it is possible to suppress the generation of algae and the like in the groundwater during exposure to sunlight.

Similarly, in the second embodiment, the drainage path 42 is branched from the recirculation path 30 on the upstream side (pumping well 14 side) of the water treatment device 34 of the purification device 24, but is on the downstream side (water injection) of the water treatment device 34. It may be branched at the well 16 side).

Further, the method of combining the purifying agent, the activator, and the fluorescent dye described above is arbitrary, and can be used in various combinations. Further, both the "purifying agent" and the "activator" may be used as the injection agent, and a plurality of types of the purifying agent may be used, or a plurality of types of the activator may be used alone.

However, it is desirable not to use a reducing agent as a purifying agent (for example, an iron-based slurry) in combination with an activator. When a plurality of different types of purifying agents and activators are used as the injecting agent to be added to the injecting solution, different types of fluorescent dyes are added to the injecting solution for each purifying agent and each activator.

Further, in the first and second embodiments, the material of the impermeable wall 20 is a steel sheet pile (sheet pile), and the lower end of the impermeable wall 20 is embedded in the impermeable layer 28. However, the lower end of the impermeable wall 20 does not have to be embedded in the impermeable layer 28, and the material of the impermeable wall 20 may be, for example, frozen soil, clay, concrete, a cement improved body, or the like.

Further, the impermeable wall 20 does not necessarily have to be provided. When the impermeable wall 20 is not provided, it is desirable to arrange the water injection well 16 on the upstream side of the groundwater flow and the pumping well 14 on the downstream side. As a result, the injection liquid injected from the water injection well 16 into the underground ground 12 can be smoothly permeated into the underground ground 12.

Further, when the groundwater is purified by using a decomposing microorganism that biodegrades a pollutant as a purifying agent, a nutrient salt or oxygen may be mixed or a new decomposing microorganism may be mixed. Further, in order to smoothly inject the injection liquid through the water injection well 16, a coagulant may be mixed.

Further, for example, in the first embodiment, the groundwater is heated by the heater in the water treatment device 34, but the embodiment of the present invention is not limited to this. For example, the groundwater may be heated by exchanging heat between the heat medium of the air conditioner (not shown) and the groundwater purified by the water treatment device 34, and exhaust heat from the contaminated ground E or a nearby building may be used. It may be heated by using steam or the like. In addition, when the degrading microorganism is active with a predetermined activity, heating is not always necessary.

Further, in the above embodiment, the fluorescent dye fading system 10 is used for purifying the contaminated ground E. However, the fluorescent dye fading system according to the present invention can also be used for investigation of groundwater flow, ground improvement, heat storage, water shielding, and the like.

For example, when the fluorescent dye fading system according to the present invention is used for the groundwater flow survey, only the fluorescent dye is added to the injection liquid without adding the injection agent, and the liquid is injected into the underground ground 12.

Specifically, a fluorescent dye solution in which a fluorescent dye is dissolved in water is injected into the underground ground 12 from the water injection well 16 as an injection liquid, and the concentration of the fluorescent dye contained in the groundwater pumped from the observation well 18 is measured. , Investigate groundwater flow. In this case, the pumping well 14 is unnecessary, and the observation well 18 corresponds to the pumping means of the present invention.

Further, for example, when the fluorescent dye fading system according to the present invention is used in a ground improvement system for measures against liquefaction of the underground ground 12, a supercooled aqueous solution, bubble mixed water, a solidifying material or the like is used as an injection agent.

Further, when used in a heat storage system for utilizing the geothermal heat of the underground ground 12, a heat storage material such as a supercooled aqueous solution is used as an injection agent. Further, when used in an impermeable system for lowering the groundwater level when excavating the underground ground 12, a supercooled aqueous solution or a solidifying material is used as an injection agent. As described above, the fluorescent dye fading system according to the present invention can be implemented in various embodiments.

10 Fluorescent dye fading system 12 Underground ground (ground)
14 Pumping well (an example of pumping means)
16 Water injection well (an example of water injection means)
22 Concentration measuring device 30 Reflux path 32 Ultraviolet irradiation device (an example of fading device)
34 Water treatment device 38 Control device

Claims (5)

A water injection means for injecting an injection solution containing a fluorescent dye into the ground,
A concentration measuring device for measuring the concentration of the fluorescent dye in the ground at a place away from the water injection means, and a concentration measuring device.
Pumping means for pumping groundwater and
A fading device for fading the fluorescent dye contained in the groundwater pumped from the pumping means, and a fading device.
The groundwater pumped from the pumping means is refluxed to the water injection means, and the reflux path provided with the fading device and the like.
A drainage route that branches from the reflux path and drains a part of the groundwater pumped from the pumping means to the outside is provided.
When the amount of groundwater pumped by the pumping means is larger than the amount of the injection liquid injected into the ground by the water injection means, a part of the groundwater pumped by the pumping means is drained from the drainage path. Optical brightener fading system. The fluorescent dye fading system according to claim 1, wherein an injection agent is added to the injection liquid, and the fluorescent dye is a substance that exhibits the same behavior as the injection agent in the ground. The fluorescent dye fading system according to claim 1 or 2, wherein the fading device is an ultraviolet irradiation device that irradiates the groundwater with ultraviolet rays. A water treatment device provided in the reflux path to treat the groundwater pumped from the pumping means, and a water treatment device.
Have,
The fading device is provided in the reflux path.
The fluorescent dye fading system according to any one of claims 1 to 3. The fading device is provided on the upstream side of the branch point of the drainage route.
The fluorescent dye fading system according to claim 4.

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