JP6913559B2 - Underground soil purification system - Google Patents

Description

The present invention relates to an underground soil purification system.

An underground soil purification system is known that enhances the purification efficiency of contaminated soil by injecting a heated injection solution into contaminated soil from an injection well and heating the contaminated soil (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-205806

In recent years, energy saving has been desired, but energy saving is also desired in the above-mentioned underground soil purification system.

An object of the present invention is to save energy in an underground soil purification system in consideration of the above facts.

The underground soil purification system according to the first aspect is provided in the soil and uses an injection well for injecting the injection liquid into the soil and a cogeneration system exhaust heat, unused heat, and at least one of renewable energy as a heat source or an energy source. A heating device for heating the injection liquid supplied to the injection well is provided.

According to the underground soil purification system according to the first aspect , the soil is provided with an injection well for injecting the injection liquid into the soil. The injection liquid supplied to the injection well is heated by a heating device. As a result, for example, microorganisms that decompose pollutants in soil (hereinafter referred to as “degrading microorganisms”) are proliferated and activated, and the pollutants are easily exfoliated from the soil. Therefore, the efficiency of soil purification is improved.

In addition, the heating device uses at least one of the exhaust heat, unused heat, and renewable energy of the cogeneration system as a heat source or an energy source to heat the injection liquid supplied to the injection well. As a result, energy saving can be achieved.

As described above, in the present invention, energy saving can be achieved while increasing the soil purification efficiency.

Examples of unused heat include sewage heat, subway exhaust heat, solar heat, waste incineration exhaust heat, factory exhaust heat, and substation exhaust heat. In addition, examples of renewable energy include wind power, geothermal energy, solar power, and wave power.

The underground soil purification system according to the second aspect is an underground soil purification system that discharges heat from an injection well provided in the soil and injects an injection liquid into the soil, and a plurality of cogeneration systems having different amounts of excess heat exhausted for a predetermined time. A heating device that heats the injection liquid supplied to the injection well as a heat source is provided.

According to the underground soil purification system according to the second aspect , the soil is provided with an injection well for injecting the injection liquid into the soil. The injection liquid supplied to the injection well is heated by a heating device. As a result, for example, degrading microorganisms in the soil are proliferated and activated, and pollutants are easily exfoliated from the soil. Therefore, the efficiency of soil purification is improved.

Further, the heating device heats the injection liquid supplied to the injection well by using the exhaust heat of a plurality of cogeneration systems having different amounts of excess heat exhausted for a predetermined time as a heat source. In this case, the excess exhaust heat can be efficiently used (reduced) by heating the injection liquid using the exhaust heat of the cogeneration system having a large amount of excess exhaust heat as a heat source for a predetermined time.

Therefore, in the present invention, energy saving can be achieved as compared with the case where the exhaust heat of one cogeneration system is used as a heat source.

The underground soil purification system according to the third aspect is the underground soil purification system according to the second aspect, in which the plurality of cogeneration systems are installed in different structures.

According to the underground soil purification system according to the third aspect , the plurality of cogeneration systems are installed in different structures.

Here, depending on the structure, the heat demand, that is, the amount of excess heat exhausted may differ depending on the time zone. In particular, in structures with different uses such as general households (general houses), offices (offices), hotels, factories, hospitals, commercial facilities, etc., the amount of excess heat exhausted often differs depending on the time of day.

Therefore, in the present invention, the exhaust heat of the cogeneration system installed in each of the plurality of structures is used as the heat source. As a result, the injection liquid can be heated by using the exhaust heat of a plurality of cogeneration systems having different amounts of excess exhaust heat depending on the time zone as a heat source. Therefore, in the present invention, energy saving can be achieved as compared with the case where the exhaust heat of the cogeneration system installed in one structure is used as the heat source.

As described above, according to the underground soil purification system according to the present invention, the underground soil purification system can save energy.

It is a vertical sectional view which shows the ground to which the underground soil purification system which concerns on one Embodiment was applied. (A) is a graph showing an example of daily power demand of a predetermined structure, and (B) is a graph showing an example of daily heat demand of the same structure. (A) is a graph showing an example of daily power demand of a store, and (B) is a graph showing an example of daily heat demand of the store. (A) is a graph showing an example of the daily power demand of the hospital, and (B) is a graph showing an example of the daily heat demand of the hospital. (A) is a graph showing the heat demand of a predetermined structure, and (B) is a graph showing the heat demand of another predetermined structure.

Hereinafter, the underground soil purification system according to the embodiment will be described with reference to the drawings.

(Underground soil purification system)
FIG. 1 shows an example of the ground 12 to which the underground soil purification system 10 according to the present embodiment is applied. The ground 12 has a poorly permeable layer 12A and an aquifer 12B deposited on the poorly permeable layer 12A. The reference numeral S shown in FIG. 1 indicates the groundwater level of the aquifer 12B. The arrow V shown in FIG. 1 indicates the flow of groundwater.

The aquifer 12B has a higher water permeability than the impervious layer 12A, and groundwater can easily flow. The aquifer 12B has a contaminated soil 12B1 containing a pollutant such as VOC (volatile organic compound).

Examples of contaminants include toluene and xylene contained in organic compounds (paints, printing inks, adhesives, cleaning agents, gasoline, thinners, etc.), tetrachloroethylene, trichlorethylene, cis-1,2-dichloroethylene, and chloroethylene (vinyl chloride). Volatile organic compounds such as monomer), heavy metal compounds, inorganic compounds, oils and the like can be mentioned.

The underground soil purification system 10 according to the present embodiment is not limited to the above-mentioned ground 12, and can be applied to various grounds such as the ground 12 in which the impermeable layer 12A does not exist.

A plurality of structures 50A, 50B, and 50C are erected on the ground 12. The plurality of structures 50A, 50B, 50C are structures having different uses, such as general households (general houses), offices (offices), hotels, factories, hospitals, commercial facilities, and the like. Each structure 50A, 50B, 50C has a cogeneration system (hereinafter, referred to as "cogeneration system") 52. The cogeneration system 52 produces the power and heat used in the structures 50A, 50B, 50C.

A bio method (biostimulation) is adopted in the underground soil purification system 10. In the bio method, for example, an activator solution to which an activator (nutrient) such as a sustained-release agent for hydrogen or a yeast extract is added is injected from the injection well 16 into the ground 12 to decompose the pollutants in the contaminated soil 12B1. This is a method of proliferating and activating microorganisms (hereinafter referred to as "degrading microorganisms") to promote purification of pollutants by degrading microorganisms.

Further, in the underground soil purification system 10, an injection liquid (warming liquid) heated to a higher temperature than the groundwater (normal temperature groundwater) in the aquifer 12B is injected into the aquifer 12B. As a result, the degrading microorganisms existing in the contaminated soil 12B1 are proliferated and activated, and the pollutants are easily separated from the contaminated soil 12B1 to improve the purification efficiency of the contaminated soil 12B1.

The underground soil purification system 10 includes an impermeable wall 14, an injection well 16, a pumping well 18, an observation well 20, a temperature detection unit 22, a water treatment device 30, and a heating activator generation device 40. ing.

(Immersion wall)
The impermeable wall 14 is formed in the aquifer 12B by, for example, concrete or ground improvement. Further, the impermeable wall 14 is formed in a frame shape in a plan view so as to surround the contaminated soil 12B1. The impermeable wall 14 penetrates the aquifer 12B, and its lower end is embedded in the impermeable layer 12A. This prevents the diffusion of groundwater and the like contaminated with the contaminated soil 12B1. The impermeable wall 14 may be provided as needed and may be omitted as appropriate.

(Injection well and pumping well)
The injection well 16 is arranged on one end side of the area (soil) partitioned by the impermeable wall 14. On the other hand, the pumping well 18 is arranged on the other end side of the region (soil) partitioned by the impermeable wall 14. These injection wells 16 and pumping wells 18 are formed by excavating the ground 12.

Each of the injection well 16 and the pumping well 18 penetrates the aquifer 12B of the ground 12 and reaches the impermeable layer 12A. The injection liquid supplied from the injection well 16 to the ground 12 passes through the contaminated soil 12B1 and is pumped from the pumping well 18 as shown by an arrow V.

The number, arrangement, and length of the injection well 16 and the pumping well 18 can be appropriately changed according to the range of the contaminated soil 12B1 to be purified. Further, the injection well 16 and the pumping well 18 do not necessarily have to reach the impermeable layer 12A.

(Observation well)
The observation well 20 is formed by excavating the ground 12. The observation well 20 is provided in the area partitioned by the impermeable wall 14. Further, the observation well 20 is provided in the contaminated soil 12B1. The observation well 20 is a well for observing (detecting) the concentration of pollutants, the concentration of activators, and the like in groundwater.

For example, a pumping pipe (not shown) is provided inside the observation well 20, and the groundwater of the contaminated soil 12B1 is pumped up by operating the pump provided in the pumping pipe. The concentration of the activator or the like in the pumped groundwater is measured by a concentration measuring device or the like.

It is also possible to measure the concentration of the activator or the like in the groundwater with a concentration measuring device or the like provided inside the observation well 20. It is also possible to estimate the concentration of the activator by adding an index material such as a fluorescent dye to the activator solution and measuring the concentration of the index material.

(Temperature detector)
The temperature detection unit 22 is realized by, for example, a temperature sensor or the like. The temperature detection unit 22 is buried in the contaminated soil 12B1 and detects the temperature of the groundwater in the contaminated soil 12B1. Further, a heating activator generation device 40, which will be described later, is electrically connected to the temperature detection unit 22.

The temperature detection unit 22 is not limited to the contaminated soil 12B1, and can be provided in, for example, an area surrounded by the impermeable wall 14. Further, the temperature detection unit 22 can be provided in the observation well 20. Further, the temperature detection unit 22 may detect the temperature of the groundwater pumped from the observation well 20.

(Water treatment equipment)
The water treatment device 30 includes, for example, a filtration device for filtering the groundwater pumped from the pumping well 18. A pumping well 18 is connected to the water treatment device 30 via a pipe 26. The pipe 26 is provided with a pump (not shown), and when the pump operates, the groundwater pumped from the pumping well 18 is supplied to the water treatment device 30. The pump may be provided inside the pumping well 18.

The groundwater supplied to the water treatment device 30 is water-treated by the water treatment device 30, and pollutants and the like are removed. A heating activator generation device 40 is connected to the water treatment device 30 via a pipe 32.

(Warming activator generator)
The heating activator generation device 40 includes a storage tank that stores groundwater as an injection liquid, an addition device that adds an activator to the storage tank, and a heating device 42 that heats the injection liquid stored in the storage tank. Have. The heating activator generating device 40 controls the operation of the adding device so that the concentration of the activator (concentration of the activator in the groundwater) of the contaminated soil 12B1 becomes a predetermined value.

Specifically, the heating activator generator 40 operates the addition device when the concentration of the activator in the groundwater observed in the observation well 20 is less than a predetermined value, and causes the activator to be added to the storage tank. .. On the other hand, the heating activator generation device 40 stops the addition device when the concentration of the activator in the groundwater observed in the observation well 20 is equal to or higher than a predetermined value. As a result, an injection liquid in which the concentration of the additive is a predetermined value (predetermined range) is generated.

A cogeneration system 52 of a plurality of structures 50A, 50B, and 50C is connected to the heating device 42. The heating device 42 uses the exhaust heat supplied from the cogeneration system 52 as a heat source to heat the injection liquid stored in the storage tank. As a result, an injection liquid (warming liquid) having a temperature of a predetermined value (predetermined range) is generated.

Further, the heating activator generating device 40 controls the operation of the heating device 42 so that the temperature of the groundwater in the contaminated soil 12B1 becomes a predetermined value. Specifically, the temperature detection unit 22 described above is electrically connected to the heating activator generation device 40.

When the temperature of the groundwater in the contaminated soil 12B1 detected by the temperature detection unit 22 is less than a predetermined value, the heating activator generator 40 operates the heating device 42 to heat the injection liquid in the heating tank. do. On the other hand, the heating activator generation device 40 stops the heating device 42 when the temperature of the groundwater in the contaminated soil 12B1 detected by the temperature detection unit 22 is equal to or higher than a predetermined value. As a result, the temperature of the groundwater in the contaminated soil 12B1 is maintained at a predetermined value (predetermined range).

The heating activator generator 40 is set so that, for example, the temperature at which the decomposing microorganisms in the contaminated soil 12B1 can easily grow and activate (for example, 25 ° C to 60 ° C, more preferably 25 ° C to 30 ° C) is reached. Adjust the temperature of groundwater in contaminated soil 12B1.

An injection well 16 is connected to the heating activator generator 40 via a pipe 44. Further, the pipe 44 is provided with an injection pump (not shown). When this injection pump operates, the activator is added by the heating activator generator 40, and the injected liquid heated at a predetermined temperature is injected from the injection well 16 into the ground (soil) 12. As a result, the concentration of the activator in the contaminated soil 12B1 is maintained at a predetermined value (predetermined range), and the temperature of the groundwater in the contaminated soil 12B1 is maintained at a predetermined value (predetermined range).

(Action)
Next, the operation of this embodiment will be described.

(Purification method of contaminated soil)
First, an example of a method for purifying contaminated soil by the underground soil purification system according to the present embodiment will be described.

The heating activator generator 40 adds the activator to the injection liquid in the storage tank so that the concentration of the activator in the contaminated soil 12B1 becomes a predetermined value. Further, the heating activator generation device 40 heats the injection liquid in the storage tank so that the temperature of the groundwater in the contaminated soil 12B1 becomes a predetermined value. At this time, the heating device 42 of the heating activator generation device 40 heats the injection liquid in the storage tank using the exhaust heat of the plurality of cogeneration systems 52 as a heat source. Then, the injection liquid to which the activator is added and heated is supplied to the injection well 16 via the pipe 44, and is injected from the injection well 16 into the ground (soil) 12.

The injectable solution injected into the ground 12 is supplied with the contaminated soil 12B1 as indicated by the arrow V. As a result, the degrading microorganisms in the contaminated soil 12B1 are proliferated and activated, and the pollutants are easily exfoliated from the contaminated soil 12B1. Therefore, the purification efficiency of the contaminated soil 12B1 is enhanced.

The injection liquid (groundwater) that has passed through the contaminated soil 12B1 is pumped from the pumping well 18. Further, the groundwater pumped from the pumping well 18 is supplied to the water treatment device 30 via the pipe 26, and is treated by the water treatment device 30. The groundwater treated by the water treatment device 30 is supplied to the heating activator generating device 40 via the pipe 32, and is stored as an injection liquid in the storage tank of the heating activator generating device 40.

As described above, the heating activator generator 40 adds the activator to the injection liquid in the storage tank so that the concentration of the activator in the contaminated soil 12B1 becomes a predetermined value. Further, the heating activator generation device 40 heats the injection liquid in the storage tank so that the temperature of the groundwater in the contaminated soil 12B1 becomes a predetermined value. This injection liquid is supplied to the injection well 16 via the pipe 44, and is injected again from the injection well 16 into the contaminated soil 12B1.

As described above, in the underground soil purification system 10 according to the present embodiment, the contaminated soil 12B1 is circulated while circulating the groundwater (injection liquid) between the contaminated soil 12B1, the water treatment device 30, and the heating activator generating device 40. Purify.

(Warming device)
Next, the operation of the heating device will be described.

As described above, the heating device 42 heats the groundwater using the exhaust heat of the plurality of cogeneration systems 52 as a heat source. Each cogeneration system 52 is installed in structures 50A, 50B, 50C and generates electric power and heat used in the structures 50A, 50B, 50C.

Here, FIG. 2 (A) shows an example of the daily power demand of the predetermined structure, and FIG. 2 (B) shows an example of the daily heat demand of the same structure. ing. The graph E in FIG. 2A shows the power demand of the predetermined structure, and the graph e shows the power generated by the cogeneration system 52. Further, the graph H in FIG. 2B shows the heat demand of the predetermined structure, and the graph h shows the exhaust heat generated by the cogeneration system 52. The same applies to the graphs E, e, H, and h of FIGS. 3 to 7, which will be described later.

As can be seen from FIGS. 2 (A) and 2 (B), in the predetermined structure, the power demand and the heat demand differ depending on the time zone. In this case, as shown in FIG. 2A, by operating the cogeneration system 52 during the peak time of the electric power demand, for example, the amount of commercial electric power used can be efficiently reduced.

On the other hand, as shown in FIG. 2 (B), the heat demand is small during the peak time of the power demand. Therefore, when the cogeneration system 52 is operated during the peak time of the electric power demand, excess exhaust heat h1 exceeding the heat demand is generated. Energy saving can be achieved by heating the groundwater using the excess exhaust heat h1 as a heat source of the heating device 42.

Further, in the present embodiment, the exhaust heat of the plurality of cogeneration systems 52 is used as a heat source to heat the injection liquid. Here, depending on the structures 50A, 50B, and 50C, the heat demand, that is, the amount of excess heat exhausted may differ depending on the time zone. In particular, in structures with different uses such as general households (general houses), offices (offices), hotels, factories, hospitals, commercial facilities, etc., the amount of excess heat exhausted often differs depending on the time of day.

For example, FIG. 3 (A) shows an example of daily power demand of a store (structure), and FIG. 3 (B) shows an example of daily heat demand of the store. ing. On the other hand, FIG. 4 (A) shows an example of the daily power demand of the hospital (structure), and FIG. 4 (B) shows an example of the daily heat demand of the hospital. ing.

As can be seen from FIGS. 3 (A), 3 (B), 4 (A), and 4 (B), the daily electricity demand and heat demand are different between the store and the hospital. In particular, as shown in FIGS. 3 (A) and 3 (B), there is no electricity demand or heat demand in the store in the early morning (about 0 to 6 o'clock) and midnight (about 21 to 24:00). Therefore, the cogeneration system 52 is stopped.

Therefore, for example, when only the cogeneration system 52 installed in the store is connected to the heating device 42, the injection liquid cannot be heated in the early morning and late at night. Alternatively, it may be costly because another heat source is required to heat the injectate.

On the other hand, in the hospital, the cogeneration system 52 is operating because there is a demand for electricity and heat in the early morning and late at night. That is, the amount of excess heat exhausted in the early morning and late at night differs between the store and the hospital. In this case, for example, when the cogeneration system 52 installed in the store and the hospital is connected to the heating device 42, the exhaust heat (excess exhaust heat) of the cogeneration system 52 installed in the hospital is used as a heat source and injected in the early morning and late at night. The liquid can be heated.

Further, FIG. 5 (A) shows the heat demand of the above-mentioned predetermined structure (hereinafter referred to as “structure X”), and FIG. 5 (B) shows other uses different from those of the structure X. The heat demand of the predetermined structure (hereinafter referred to as “structure Y”) is shown. As can be seen from FIGS. 5 (A) and 5 (B), in the two structures X and Y, the amount of excess heat generated by the cogeneration system 52 (excess heat exhaust h1) in the time zone of about 10 to 18 o'clock. Is different.

In this case, the heating device 42 uses the exhaust heat of the cogeneration system 52 installed in the structure A having a large amount of excess exhaust heat as the heat source among the two structures A and B, thereby making the excess exhaust heat h1 efficient. Can be used (reduced).

In consideration of the above, in the present embodiment, the cogeneration system 52 installed in the plurality of structures 50A, 50B, and 50C having different uses is connected to the heating device 42. That is, in the present embodiment, a plurality of cogeneration systems 52 having different amounts of excess heat exhausted in a predetermined time are connected to the heating device 42. As a result, the heating device 42 can heat the injection liquid in a predetermined time by using the exhaust heat of the cogeneration system 52, which has a large amount of excess heat exhausted, as a heat source among the plurality of cogeneration systems 52. Therefore, energy saving can be achieved.

The "predetermined time" in the present embodiment may be not only a specific time but also a time zone having a range (predetermined time zone).

(Modification example)
Next, a modified example of the above embodiment will be described.

The heating device 42 of the above-described embodiment uses the exhaust heat of a plurality of cogeneration systems 52 having different amounts of excess heat exhausted for a predetermined time as a heat source, but the above-described embodiment is not limited to this. The heating device may use the exhaust heat of a plurality of cogeneration systems 52 having the same amount of excess exhaust heat for a predetermined time as a heat source.

Further, the heating device can heat the injection liquid injected into the injection well 16 by using the exhaust heat of at least one cogeneration system installed in one structure as a heat source.

Further, the heating device 42 of the above-described embodiment uses the exhaust heat of the cogeneration system 52 (cogeneration system exhaust heat) as a heat source, but the above-described embodiment is not limited to this. The heating device can heat the injection liquid supplied to the injection well 16 by using at least one of the cogeneration system exhaust heat, unused heat, and renewable energy as a heat source or energy source, for example. As a result, energy saving can be achieved as in the above embodiment.

The "unused heat" here means, for example, sewage heat, subway exhaust heat, solar heat, waste incineration exhaust heat (exhaust heat generated when burning waste, etc.), factory exhaust heat (generated in the product manufacturing process). Exhaust heat, etc.) and substation exhaust heat (exhaust heat generated when the transformer is cooled), etc. can be mentioned. In addition, examples of renewable energy include wind power, geothermal energy, solar power, and wave power.

Further, in the above embodiment, biostimulation is used as the biomethod, but the present invention is not limited to this. For example, bioaugmentation in which an externally cultured microorganism is injected into contaminated soil 12B1 together with an activator or the like may be used. Further, the bio method may be used as needed and can be omitted as appropriate.

Further, in the above embodiment, the pumping well 18 is provided in the ground 12, but the above embodiment is not limited to this. The pumping well 18 may be provided as needed and may be omitted as appropriate.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modifications may be used in combination as appropriate. Of course, it can be carried out in various modes as long as it does not deviate.

10 Underground soil purification system 12 Ground (soil)
16 Injection well 42 Heating device 50A Structure 50B Structure 50C Structure 52 Cogeneration system

Claims (1)

An injection well provided in the soil to inject the injection solution into the soil,
A heating device that heats the injection liquid supplied to the injection well by using the exhaust heat of a plurality of cogeneration systems having different amounts of excess heat exhausted for a predetermined time as a heat source.
Equipped with a,
The cogeneration system is installed in a plurality of structures having different uses.
Underground soil purification system.

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