JP2021171696A - Purification apparatus and purification method - Google Patents

Abstract

To provide a purification apparatus and a purification method that can shorten a purification treatment time and sustain ozone as a purification gas in groundwater.SOLUTION: The purification apparatus that purifies the groundwater by supplying an ozone gas to sparging wells in soil comprises: a raw material gas supply part that supplies a raw material of the ozone gas to an ozone generator; a flow channel switching part that switches a fluid flow channel; a maintaining body supply part that supplies an ozone generator with a maintaining body that suppresses autolysis of the ozone gas, and supplies the maintaining body to the sparging well via the flow channel switching part by sending the maintaining body to an outlet side of an ozone generator; and a control part that starts or stops generation of the ozone gas to open and close a valve of the flow channel switching part by transmitting command signals separately to the ozone generator, the flow channel switching part and the maintaining body supply part, and then separately controls an amount of the maintaining body supplied to the ozone generator and the sparging well.SELECTED DRAWING: Figure 1

Description

The present application relates to a purification device and a purification method.

Recently, soil contamination by organic matter has become apparent in soil contamination surveys on the site of factories and the like. Examples of pollutants include organic chlorine compounds such as tetrachlorethylene (also known as PCE) and trichlorethylene (abbreviated as TCE), which are classified into volatile organic compounds (hereinafter referred to as "VOC"), and purify them. There is an air sparging treatment method that disperses air into the soil from a well installed in the ground. The air sparging treatment method refers to a purification method in which pollutants (for example, volatile organic substances) in the soil are volatilized by blowing air into the soil, and both the volatilized pollutants (organic substances) and gas are recovered. ..

Conventionally, a method for in-situ purification of soil has been proposed in which oxygenated oxygen (hereinafter referred to as "ozone") gas is used as a sparging gas dispersed in the soil. This purification method is a soil purification method that uses the oxidizing power of ozone dissolved in groundwater in addition to the removal of VOCs by the air sparging treatment method.

Here, all of the conventional purification devices using ozone gas promote the decomposition of ozone dissolved in groundwater and generate radicals having a larger oxidizing power than ozone to improve the decomposition rate of VOC. rice field.

As a specific detailed configuration example of the conventional purification device, for example, a purification gas supply device that supplies a purification gas containing ozone as a composition gas to the ground through a purification pipe buried in the ground, and a purification gas supply device. A water supply device that supplies water to the ground through a pipe, a predetermined purification gas supply time for supplying purification gas by the purification gas supply device, and a predetermined alkaline liquid supply by the water supply device. Some are provided with a control device for controlling the timing of supplying the purification gas and the alkaline liquid so as to alternately repeat the water supply time (see, for example, Patent Document 1).

Japanese Patent No. 4217836

According to the conventional purification device and purification method as described above, since the time for supplying the purification gas and the time for supplying the alkaline liquid are alternately repeated, there is a time when the purification gas cannot be supplied, and the purification treatment time is long. Therefore, there is a problem that the purification gas is decomposed in the alkaline liquid container and the ozone of the purification gas is not sustained in the ground water.

This application has been made to solve the above-mentioned problems, and it is possible to inject a purification gas and a sustainer into the groundwater in the soil at the same time, and the self of ozone dissolved in the groundwater in the soil. It is an object of the present invention to provide a purification device and a purification method for suppressing decomposition and improving in-situ decomposition removal of groundwater pollutants in soil.

The purification device disclosed in the present application is
A purification device that purifies groundwater by supplying ozone gas generated by an ozone generator to a sparging well in the soil.
A raw material gas supply unit installed on the inlet side of the ozone generator and supplying a fluid as a raw material for the ozone gas to the ozone generator.
A flow path switching unit installed on the outlet side of the ozone generator and having a valve to switch the fluid flow path,
A sustainer that is connected to both the inlet side and the outlet side of the ozone generator and suppresses autolysis of the ozone gas is supplied to the ozone generator, and is connected to the sparging well via the flow path switching portion. The sustaining body supply unit that supplies the sustaining body and
By separately transmitting a command signal to the ozone generator, the flow path switching unit, and the sustaining body supply unit, the sustaining body is sparged while the ozone gas is supplied to the sparging well. A control unit that controls the supply to the well,
It is equipped with.

The purification methods disclosed in the present application are:
In a purification method that purifies groundwater using sparging wells that are inserted into the soil
The first step to generate ozone gas with an ozone generator,
The second step of introducing the sustainer that suppresses the autolysis of ozone gas into the sparging well, and
A third step of measuring the pressure of the fluid at the outlet of the ozone generator and the pressure of the fluid at the inlet of the sparging well, and
When the pressure of the fluid at the outlet of the ozone generator is smaller than the pressure of the fluid at the inlet of the sparging well, the valve installed on the outlet side of the ozone generator is opened and the ozone generator is used. The fourth step of introducing the generated fluid into the sparging well, and
Is included.

According to the purification device and purification method disclosed in the present application, the purification gas and the sustaining substance can be simultaneously injected into the groundwater in the soil, suppressing the self-decomposition of ozone dissolved in the groundwater in the soil, and suppressing the self-decomposition of ozone dissolved in the groundwater in the soil. It will be possible to provide purification devices and purification methods that improve in-situ decomposition and removal of groundwater pollutants in soil.

It is a figure which shows the structure of the purification apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the 1st flow path switching part shown in FIG. It is a figure which shows the structure of the sustaining body part shown in FIG. It is a figure which shows the timing chart of the purification method of the purification apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the purification apparatus which concerns on Embodiment 2.

The purification device and the purification method according to the embodiment of the present application will be described below. The purification device according to the embodiment of the present application uses ozone gas as a sparging gas in the gas sparging method, and purifies the contamination by pollutants such as VOC in the original position.

Embodiment 1.
The purification device 200a according to the first embodiment will be described with reference to the following figures. The purification device 200a of the first embodiment is configured to supply ozone gas used as the sparging gas as well as a "sustaining body" that suppresses autolysis of ozone dissolved in groundwater in the soil. ..

Here, the sustaining substance is a substance that suppresses the self-decomposition of ozone dissolved in the groundwater of the soil and prolongs the half-life of the ozone concentration in the groundwater. The half-life of ozone concentration is the time required to reduce the ozone concentration in groundwater by half, and the longer the half-life, the more the ozone concentration in groundwater is maintained.

FIG. 1 is a diagram showing a configuration of a purification device according to the first embodiment. FIG. 1 shows a contaminated region 100, which is a region in the soil in which the soil is contaminated by pollutants (VOC, etc.). A sparging well 1 (hereinafter, abbreviated as a well 1) inserted into the contaminated area 100 is installed in the central portion of the contaminated area 100. The well 1 is composed of pipes buried in the soil.

On the lower end side of the well 1, a ejection portion 11 for supplying ozone gas and a sustaining material into the soil is formed. The ejection portion 11 is a portion in which one or more holes or slits are formed in the piping of the well 1. Further, the well 1 is configured to be provided with a sealing member at the upper end so that ozone gas and the sustaining material do not leak to the outside air (atmosphere) from the upper end of the well 1. A plurality of wells 1 may be installed in the contaminated area 100, but here, a case where one well 1 is installed will be described below as an example.

As shown in FIG. 1, the ozone generator 2 is connected to the well 1 via the pipe 8, the first flow path switching portion 6a, and the pipe 3121. The ozone generator 2 is for supplying ozone gas to the well 1. Further, the ozone generator 2 is connected to a raw material gas supply unit 3 that supplies a raw material gas via a pipe 31 and a sustaining body supply unit 4 that supplies a sustainable material via a pipe 41.

In the above description, the case where the pipe 31 and the pipe 41 are separately connected to the ozone generator 2 and supplied has been described as an example, but the present invention is not limited to this, and the pipe 31 and the pipe 41 are connected and merged. After that, it may be connected to the ozone generator 2 to supply both the raw material gas and the sustaining material to the ozone generator 2.

In addition, there is an example of using oxygen gas or oxygen gas mixed with nitrogen gas as the raw material gas supplied by the raw material gas supply unit 3, but here, when oxygen gas is used as the raw material gas and carbon dioxide gas is used as the sustaining substance. Will be described as an example.

In the ozone generator 2, oxygen is supplied as a raw material gas from the raw material gas supply unit 3 via the pipe 31, and carbon dioxide gas is supplied from the sustainable body supply unit 4 via the pipe 41 to generate ozone gas. The ozone generator 2 includes, for example, a pressure vessel and a discharge electrode arranged in the pressure vessel. Then, oxygen gas and carbonic acid gas are supplied into the pressure vessel from the piping of the raw material gas supply unit. Then, ozone gas is generated by the discharge of the discharge electrode, and the ozone gas is sent from the pipe 21 to the well 1 via the first flow path switching portion 6a and the pipe 8.

As described above, the ozone generator 2 is connected to the first flow path switching unit 6a via the pipe 21, and the sustaining body supply unit 4 is connected to the pipe 21 via the pipe 42. It is connected. Further, the pipe 101 and the pipe 8 are connected to the first flow path switching unit 6a, and the pipe 21 and the flowing pipe are switched by the first flow path switching unit 6a. Further, the pipe 101 is connected to the exhaust gas treatment unit 10, and the pipe 8 is connected to the well 1. Further, a pressurized fluid supply unit 7 is connected to the pipe 8 via the pipe 71 between the first flow path switching unit 6a and the well 1. Further, in the pipe 71, a second flow path switching unit 6b is arranged between the pressurized fluid supply unit 7 and the pipe 8 to switch the opening and closing of the pipe 71.

The pressurized fluid supply unit 7 supplies a feeder, which is a pressurized gas different from ozone gas, into the soil. The pressurized feeder is a gas different from ozone gas, and naturally is a gas that does not promote the autolysis of ozone. Here, pressurized air will be described below as an example.

The pressurized fluid supply unit 7 is composed of a blower or a compressor. Therefore, the pressurized fluid supply unit 7 can adjust the supply amount of the pressurized air by adjusting the output of the blower or the compressor.

The control unit 5 controls the ozone generator 2, the raw material gas supply unit 3, the sustaining body supply unit 4, the pressurized fluid supply unit 7, the first flow path switching unit 6a, and the second flow path switching unit 6b. .. The control unit 5 and the ozone generator 2 are connected via the first signal line 9a. The control unit 5 and the sustaining body supply unit 4 are connected via the second signal line 9b. The control unit 5 and the pressurized fluid supply unit 7 are connected via a third signal line 9c. The control unit 5 and the first flow path switching unit 6a are connected via the fourth signal line 9d. The control unit 5 and the second flow path switching unit 6b are connected via a fifth signal line 9e.

The pressurized fluid supply unit 7 supplies a pressurized feeder different from ozone gas into the soil. The pressurized feeder is a gas different from ozone gas, and naturally is a gas that does not promote the autolysis of ozone. Here, an example in which pressurized air is used is shown.

The pressurized fluid supply unit 7 is composed of a blower or a compressor. Therefore, the pressurized fluid supply unit 7 can adjust the supply amount of the pressurized air by adjusting the output of the blower or the compressor. In a specific example, the ejection pressure of the pressurized air of the pressurized fluid supply unit 7 is considered to be 0.1 MPa to 1.5 MPa, preferably 0.15 MPa to 1 MPa as an absolute pressure. If the air pressure is less than 0.1 MPa, it will be lower than the atmospheric pressure and cannot be efficiently supplied to groundwater. Further, when the air pressure is 1.5 MPa or more, the power consumption of the pressurized fluid supply unit becomes large, the device becomes large, and the cost becomes high.

The control unit 5 is composed of, for example, a personal computer. The control unit 5 transmits a signal for starting ozone generation and a signal for stopping ozone generation to the ozone generator 2 on the first signal line 9a. The control unit 5 sends a signal to the sustaining body supply unit 4 on the second signal line 9b in synchronization with a signal of starting ozone generation and a signal of stopping ozone generation, and a signal to start supplying the sustaining body to the pipe 41. And send a signal to stop the supply of the sustainer. The control unit 5 synchronizes with the switching signal of the first flow path switching unit 6a to the sustaining body supply unit 4 on the second signal line 9b, and signals the start of supply of the sustaining body to the pipe 42 and the continuation. Sends a signal to stop the supply of the chemical.

Further, the control unit 5 reduces the signal of starting the supply of pressurized air and the signal of stopping the supply of pressurized air to the pressurized fluid supply unit 7 at the third signal line 9c, or the pressure of the injected gas of the pressurized air. Send a signal. When the pipe pressure in the pipe 21 is equal to or higher than the pipe pressure of the pipe 8, the control unit 5 opens the first flow path switching unit 6a in the direction of the pipe 8, and the pipe pressure of the pipe 21 is the pipe pressure of the pipe 8. When the pipe pressure is less than the pipe pressure, the first flow path switching portion 6a is controlled to be opened in the direction of the pipe 101. The control unit 5 transmits a signal for supplying the sustaining body to the pipe 42 in synchronization with the signal that the first flow path switching unit 6a opens in the direction of the pipe 8. After that, a signal for starting ozone generation is transmitted to the ozone generator 2 on the first signal line 9a. When the control unit is not operating, the first flow path switching unit 6a is closed to all the pipes other than the pipe 101 connected to the control unit, that is, the pipe 8, the pipe 21, and the pipe 71. There is no fluid flow with. As a result, since the sustaining substance is injected into the groundwater only during the purification period of the groundwater, the amount of the sustaining substance used can be suppressed.

As an example of the control of the control unit 5, when the control unit 5 transmits a signal for injecting the gas of the pipe 21 into the ground water, the control unit 5 causes the first measurement unit 600 of the first flow path switching unit 6a. The first measured value of the pipe pressure in the pipe 21 and the second measured value of the pipe pressure in the pipe 8 in the second measuring unit 601 are input. When the first measured value and the second measured value are the same or the first measured value is higher than the second measured value, the valve 602 is controlled from the closed state to the open state, and the valve 603 is controlled from the open state to the closed state. .. The first measured value of the first measuring unit 600 may substitute the value of the gas pressure measured on the ozone generator 2 side of the first flow path switching unit 6a.

Upon receiving the start signal for starting the injection of pressurized air into the groundwater in the contaminated region 100, the control unit 5 controls the second flow path switching unit 6b from the closed state to the open state, and the pressurized fluid supply unit 7 The injection of pressurized air into the groundwater of the contaminated area 100 is started from. Further, when the control unit 5 transmits a signal for injecting the gas of the pipe 21 into the groundwater, the control unit 5 controls the second flow path switching unit 6b from the open state to the closed state, and the pressurized fluid supply unit 7 controls the contaminated area 100. Stop injecting pressurized air into the groundwater.

As shown in FIG. 3, the sustaining body supply unit 4 has a flow rate adjusting valve (mass flow controller) shown as a sustaining body flow rate adjusting unit 4a and a sustainable body flow rate adjusting unit 4b in the pipe 41 and the pipe 42, respectively. The flow rate of the pressure-adjusted sustaining body installed and supplied from the storage unit 4c provided in the sustaining body supply unit 4 can be controlled according to a command from the control unit. This makes it possible to control the amount and timing of adding the sustaining material to the ozone gas.

When the control unit 5 transmits a signal for starting the operation of the ozone generator 2, the sustaining body flow rate adjusting unit 4a adjusts the flow rate of the sustaining body and sends the sustaining body to the pipe 41. After transmitting a signal for injecting the gas of the pipe 21 into the contaminated region 100, the control unit 5 adjusts the flow rate of the sustaining body by the sustaining body flow rate adjusting unit 4b, and pipes the sustaining body 21 via the pipe 42. Send to.

The flow rate of the sustaining body flow rate adjusting unit 4b can be changed according to the flow rate specified by the control unit according to the groundwater quality of the contaminated area 100. By adding a sustainer to the latter stage of the ozone generator, that is, to the portion of the pipe 21, the ratio of the sustainer flow rate to the oxygen gas flow rate introduced into the ozone generator 2 can be reduced to reduce the ratio of the sustainer flow rate to the raw material gas. Since the oxygen concentration can be increased, ozone gas can be generated under the optimum conditions for the operation of the ozone generator 2.

If the amount of sustainer injected into the groundwater is insufficient for the amount required to maintain the ozone concentration in the groundwater of the contaminated area 100, in order to make up for the shortage, in the latter stage of the ozone generator 2. Mix ozone gas and sustainer. As a result, it is possible to inject an amount of sustaining material necessary for maintaining the concentration of ozone dissolved in the groundwater of the contaminated region 100 into the groundwater at the same time as ozone gas. As a result, the ozone concentration required for purification can be adjusted according to the change in the water quality of the groundwater in the contaminated area, and the decomposition treatment time of the pollutant can be shortened.

When the control unit 5 receives the start-up signal of the ozone generator 2, the control unit 5 introduces the raw material gas from the raw material gas supply unit 3 and the sustainer from the sustainer supply unit 4 into the ozone generator 2, respectively. The control unit 5 starts ozone generation when it receives a signal for injecting the gas of the pipe 21 into the groundwater, and stops ozone generation when it receives a signal for introducing the gas of the pipe 21 into the exhaust gas treatment unit 10. Further, when the control unit 5 receives the shutdown signal of the ozone generator 2, the control unit 5 performs the ozone generator shutdown process (stops the generation of ozone gas), and the sustainer from the sustainer supply unit 4 to the pipe 21. Stop sending.

Next, a purification method using the purification device of the first embodiment configured as described above will be described. The first embodiment includes a step of generating ozone gas, a step of supplying ozone gas and a sustaining substance into the soil, and a step of supplying pressurized air into the soil.

In the step of generating ozone gas, oxygen gas and carbon dioxide gas are introduced into the ozone generator 2, ozone gas is generated by discharging the discharge electrode, and the generated ozone gas is sent to the pipe 21. A part of the delivered ozone gas flows to the exhaust gas treatment unit 10 via the pipe 101 via the first flow path switching unit 6a, and the gas from which the ozone gas has been removed is released to the atmosphere.

In the step of supplying the pressurized air, the pressurized air is supplied to the contaminated region 100 from the ejection portion 11 of the well 1 via the pipe 71 and the pipe 8.

In the step of supplying the ozone gas and the sustaining material, of the ozone gas generated by the ozone generator 2, the ozone gas and the sustaining material that were not discharged to the exhaust gas treatment unit 10 are ejected from the lower part of the well 1 through the pipe 8. It is supplied from the part 11 to the contaminated area 100. Then, the ozone gas and the sustaining material supplied into the soil are dispersed in the soil to form bubbles, which rise in the soil of the contaminated region 100. Then, ozone is dissolved from the bubbles into the soil by using the concentration gradient between the bubbles and the gas-liquid interface in the soil as a driving force.

Ozone dissolved in groundwater is consumed by reaction with pollutants (such as VOCs) and oxidized substances in soil, or by self-decomposition of ozone. Ozone not consumed in those reactions is detected as dissolved ozone in groundwater. Ozone detected in groundwater permeates the soil and contributes to the decomposition of pollutants. In addition, the sustainer can suppress the autolysis of ozone dissolved in groundwater. Therefore, ozone can reach a position away from the position where ozone gas has passed in the soil. As a result, the decomposition and removal of pollutants in the contaminated area continues without interruption.

Next, the timing of supply and stop of the ozone gas and the sustainer and the pressurized air will be described based on the example of the timing chart of FIG.
FIG. 4 shows a series of operations for the purification method for one cycle of the purification device of the first embodiment. In this specific example, the operation for one cycle is divided into three steps T1, T2, and T3. Steps T1, T2, and T3 indicate the timing of supplying or stopping the supply or stop of ozone gas, the sustainer, and the pressurized air, respectively. The timing chart shown in FIG. 4 is an example, and other examples may be considered, for example, when there is a stop time in which none of the ozone gas, the sustaining body, and the pressurized air is supplied.

The purification method shown in FIG. 4 will be described. First, in the T1 step, the valve 602 is closed and pressurized air is supplied to the contaminated region 100. The raw material gas supply unit 3 supplies the raw material gas, and the sustaining body flow rate adjusting unit 4a of the sustaining body supply unit 4 supplies the sustaining body to the ozone generator 2, respectively, and the sustaining body of the sustaining body supply unit 4 The flow rate adjusting unit 4b does not supply the sustaining body (stops the supply).

Next, in the T2 step, the valve 602 is opened, the raw material gas supply unit 3 uses the raw material gas, and the sustaining body flow adjustment unit 4a of the sustaining body supply unit 4 sends the sustaining body to the ozone generator. The ozone gas generated by the ozone generator is supplied, and the sustaining body flow rate adjusting unit 4b of the sustaining body supply unit 4 supplies the sustaining body to the well 1 via the first flow path switching unit. Stop the supply of pressurized air.

In the T3 step, the valve 602 is closed, the raw material gas supply unit 3 supplies the raw material gas, the sustaining body flow rate adjusting unit 4a supplies the sustaining body, and the supply of the sustaining body flow rate adjusting unit 4b is stopped. (Stop). The supply of pressurized air remains stopped (stopped). In such a case, the open / closed state of the first flow path switching unit 6a and the second flow path switching unit 6b, and the control of the sustained body flow rate adjusting unit 4a and the sustained body flow rate adjusting unit 4b will be described. Before driving the purification device, both the first flow path switching unit and the continuous body flow rate adjusting unit are closed.

At the start timing of the T1 process, the control unit 5 opens the second flow path switching unit 6b via the fifth signal line 9e, and the control unit 5 sets the pressurized fluid supply unit via the third signal line 9c. 7 is driven to start supplying pressurized air. The control unit 5 opens the valve 603 via the fourth signal line 9d and drives the ozone generator 2 via the first signal line 9a. At this time, the continuous body flow rate adjusting unit 4b maintains the stopped state, and the valve 602 of the first flow path switching unit 6a maintains the closed state.

Next, at the timing of starting the T2 process, the control unit 5 closes the second flow path switching unit 6b via the fifth signal line 9e and stops the supply of pressurized air. After that, the control unit 5 opens the valve 602 and closes the valve 603 via the fourth signal line 9d.

Subsequently, the control unit 5 sends the sustaining body from the sustaining body flow rate adjusting unit 4b to the pipe 21 via the second signal line 9b, and starts ozone generation via the first signal line 9a. At this time, the first pressure measurement value measured by the first flow path switching unit 6a with a pressure gauge or the like is the same as the second pressure measurement value, or the first pressure measurement value is the second pressure measurement value. When it is higher, the T1 step and the T2 step can be switched.

As a result, after switching the gas to be injected into the well 1 from the pressurized air to the raw material gas, the raw material gas is not injected into the soil from the well 1 and the gas can be prevented from flowing back, so that the ozone generator 2 fails. Can be prevented.

At the start timing of the T3 process, the control unit 5 stops ozone generation via the first signal line 9a. Synchronized with the stop of ozone generation, the delivery of the sustainer from the sustainer flow rate adjusting unit 4b to the pipe 21 via the second signal line 9b is stopped. After a lapse of a predetermined time, the valve 602 of the first flow path switching unit 6a is changed from the open state to the closed state via the fourth signal line 9d, and the valve 603 is switched from the closed state to the open state.

With the switching of the valves 602 and 603, the gas in the pipe 21 is introduced into the exhaust gas treatment unit 10 via the pipe 101. By this step, the ozone gas concentration in the pipe 8 and the well 1 can be kept low, and the risk of ozone gas leaking to the atmosphere during the purification treatment stop period can be suppressed.

According to the purification device and purification method of the first embodiment configured as described above, a gas in which oxygen gas and continuous dismantling are mixed is introduced into the ozone generator 2, and the mixed gas is started to be injected into groundwater. At the same time as the signal, the sustaining body is supplied to the mixed gas from the sustaining body flow rate adjusting unit 4b.

With this control, the ozone generator 2 can be operated under optimum conditions, and the injection amount of the sustaining agent can be adjusted according to the water quality of the purification area. By supplying a sustaining substance that sustains ozone that dissolves in groundwater together with ozone gas, self-decomposition of ozone in groundwater is suppressed, the ozone concentration in groundwater is maintained, and pollutants in the soil are maintained. Decomposition and removal of

Further, by starting ozone generation after starting the supply of the mixed gas to the groundwater, when the mixed gas flows back from the well 1 without being injected into the groundwater, the ozone generator 2 fails due to the ozone gas backflow. Can be prevented.

As described above, according to the purification device and purification method of the first embodiment, the decomposition of the contaminated substance is performed by adjusting the injection amount of the sustaining substance required for purification according to the change in the water quality of the groundwater in the contaminated area. Removal can be improved. Further, by adjusting the injection amount of ozone required for purification according to the change in the water quality of the groundwater in the contaminated area, the ozone required for the decomposition and removal of pollutants in the groundwater can be injected. Further, by injecting a sustaining substance into groundwater at the same time as ozone gas, self-decomposition of ozone dissolved in groundwater can be suppressed, the concentration of dissolved ozone in groundwater can be maintained, and pollutants in groundwater can be oxidatively decomposed.

Further, after switching the gas to be injected into the groundwater, the gas is not injected into the groundwater from the sparging well, and the gas can be prevented from flowing back, and the failure of the ozone generator can be prevented. Furthermore, by adding a sustaining substance after the ozone generator, the ozone generator is operated under certain conditions, and the amount of sustaining substance required for purification is injected into the groundwater according to changes in the groundwater quality of the contaminated area. can do.

Embodiment 2
The purification device 200b according to the second embodiment will be described with reference to the following figures. The purification device 200b of the second embodiment is provided with a mechanism for measuring the ozone gas concentration in the exhaust gas in the sucked soil in addition to the ozone gas, the sustaining body and the pressurized air, and controlling the ozone injection rate into the soil. Is.

FIG. 5 is a diagram showing a configuration of a purification device according to the second embodiment. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, a suction well 13 is provided as a suction unit that is inserted into the soil of the contaminated area 100 and sucks the exhaust gas in the soil of the contaminated area 100.

Here, a suction well 13 formed in the soil of the contaminated area 100 is shown as a typical example as a suction part for sucking the gas in the soil of the contaminated area 100, and the following description will be made on the premise of the suction well 13. do.

In the pipe 21, an ozone concentration measuring unit 12 is arranged between the ozone generator 2 and the third flow path switching unit 6c. The ozone concentration measuring unit 12 is connected to the third flow path switching unit 6c via the pipe 121, and is connected to the control unit 5 via the seventh signal line 9g. A pipe 131 is connected to the suction well 13. An exhaust gas measuring unit 14 as a measuring unit is connected to the pipe 131. The exhaust gas measuring unit 14 is connected to the control unit 5 via the eighth signal line 9h, and transmits the measurement result to the control unit 5. The suction blower 16 is connected to the exhaust gas treatment unit 15 by the pipe 151, is connected to the control unit 5 via the ninth signal line 9i, and is controlled by the control unit 5. Specifically, the control unit 5 controls the timing of starting suction of the suction blower 16 and the operation of the suction gas flow rate.

The exhaust gas measuring unit 14 measures the ozone gas concentration in the sucked exhaust gas, and transmits the measurement result to the control unit 5. The suction blower 16 is a blower as a suction unit for sucking gas from the suction well 13 via the pipe 131, and further, the gas treated with exhaust gas by the exhaust gas treatment unit 15 is released to the atmosphere.

The control unit 5 uses at least one of the ozone generator 2, the sustaining body supply unit 4, the pressurized fluid supply unit 7, and the suction blower 16 based on the ozone gas concentration measured by the exhaust gas measurement unit 14. Control. If necessary, the raw material gas supply unit 3 is controlled via the sixth signal line 9f.

In the above, the suction well 13 formed in the soil has been described as an example as a suction part for sucking the gas in the soil of the contaminated region 100, but the present invention is not limited to this, and for example, contamination. A cover may be installed on the ground surface around the well 1 on the area 100, and instead of the suction well 13, it may be a suction part for sucking the gas in the soil of the contaminated area 100, or both of them are installed. May be.

Next, a purification method of the purification device of the second embodiment configured as described above will be described. Since the method of supplying ozone gas, the sustaining body, and the pressurized air is the same as that of the first embodiment, detailed description thereof will be omitted.

When ozone gas is injected from the well 1 into the soil of the contaminated area 100, the ozone gas is dispersed in the soil. The ozone gas injected into the soil becomes bubbles in the soil, moves in the soil, and reaches the soil surface in the soil.

In the soil from the soil surface to the ground surface, the gas in the soil moves between the gaps of the soil particles. Then, the gas in the soil is sucked from the suction well 13 by using the suction blower 16, and the gas injected into the soil is promoted to be discharged to the ground. Then, the exhaust gas is introduced into the exhaust gas treatment unit 15 via the suction well 13 and the pipe 131. Then, ozone, VOC, and the like are removed from the exhaust gas by the exhaust gas treatment unit 15, and the exhaust gas is treated. Then, the gas in the soil from which the VOC and ozone have been removed and the exhaust gas has been treated is released to the atmosphere through the suction blower 16.

The result of the ozone gas concentration measured by the exhaust gas measuring unit 14 is transmitted to the control unit 5 via the eighth signal line 9h. The control unit 5 switches the process of the purification method based on the acquired measurement result of the ozone gas concentration.

In the T3 step, the ozone gas concentration injected into the groundwater is a ^{value larger than 0 g / m 3} and drops to a value of 10 g / m ³ or less, and then preferably a ^{value larger than 0 g / m 3} and 3 g. After the value drops to / m ³ or less, the valve 602 of the first flow path switching unit 6a is changed from the open state to the closed state, and the valve 603 is switched from the closed state to the open state via the fourth signal line 9d. As a result, the ozone concentration in the pipe 8 connecting the purification device and the well 1 can be controlled to be low, and ozone can be prevented from leaking to the atmosphere while the purification device is stopped.

The result of the ozone gas concentration measured by the exhaust gas measuring unit 14 is transmitted to the control unit 5 via the 78th signal line 9gh. Based on the acquired measurement result of the ozone gas concentration, the control unit 5 sets the ozone generator 2, the sustaining body supply unit 4, and the suction blower 16 so that the ozone gas concentration becomes a predetermined value previously obtained as a purification device. A signal is transmitted to at least one of them, and the concentration of ozone gas injected into the soil in the soil, the flow rate of ozone gas, the injection amount of the sustaining substance, the timing of switching each process, or the flow rate of exhaust gas sucked in the suction well 13. That is, the operation of the suction blower 16 is controlled.

According to the purification device of the second embodiment configured as described above, not only the same effect as that of the first embodiment is obtained, but also the soil is provided by using the suction well 13 inserted into the soil. In the purification device that sucks the exhaust gas inside, since the exhaust gas treatment unit 15 that treats the exhaust gas connected to the suction well 13 is provided, the exhaust gas generated based on the degree of purification in the soil can be easily treated.

As described above, according to the purification device and purification method of the second embodiment, the decomposition treatment time of pollutants is shortened by adjusting the ozone concentration required for purification according to the change in the water quality of the groundwater in the contaminated area. can.

Although the present disclosure describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Well (sparging well), 2 Ozone generator, 3 Raw material gas supply unit, 4 Sustainable fluid supply unit, 4a, 4b Sustainable fluid flow control unit, 4c Storage unit, 5 Control unit, 6a First flow path switching Section, 6b Second flow path switching section, 6c Third flow path switching section, 7 Pressurized fluid supply section, 8, 21, 31, 41, 42, 71, 101, 121, 131, 151 Piping, 9a No. 1 signal line, 9b 2nd signal line, 9c 3rd signal line, 9d 4th signal line, 9e 5th signal line, 9f 6th signal line, 9g 7th signal line, 9h 8th signal line, 9i 9th signal Line, 11 Ejection part, 12 Ozone concentration measurement part, 13 Suction well, 14 Exhaust gas measurement part, 15 Exhaust gas treatment part, 16 Suction blower, 100 Contaminated area, 200a, 200b Purifier, 600 First measurement part, 601 Second measurement Department, 602, 603 valve

Claims (6)

A purification device that purifies groundwater by supplying ozone gas generated by an ozone generator to a sparging well in the soil.
A raw material gas supply unit installed on the inlet side of the ozone generator and supplying a fluid as a raw material for the ozone gas to the ozone generator.
A flow path switching unit installed on the outlet side of the ozone generator and having a valve to switch the fluid flow path,
A sustainer that is connected to both the inlet side and the outlet side of the ozone generator and suppresses autolysis of the ozone gas is supplied to the ozone generator, and is connected to the sparging well via the flow path switching portion. The sustaining body supply unit that supplies the sustaining body and
By separately transmitting a command signal to the ozone generator, the flow path switching unit, and the sustaining body supply unit, the sustaining body is sparged while the ozone gas is supplied to the sparging well. A control unit that controls the supply to the well,
A purification device characterized by being equipped with. The flow path switching portion is provided in the middle of a pipe that supplies the ozone gas and the sustaining material to the sparging well.
When the pressure of the fluid at the fluid outlet of the ozone generator is smaller than the pressure of the fluid at the fluid inlet flowing into the sparging well, the control unit closes the flow path switching unit and sustains the flow. The purification device according to claim 1, wherein the supply of the sustaining fluid from the body supply unit is stopped, and the ozone generator is controlled to stop the generation of ozone gas. Equipped with an exhaust gas measurement unit
The sustainer is carbon dioxide
The purification device according to claim 1 or 2, wherein the control unit adjusts the amount of the sustaining body supplied from the sustaining body supply unit based on the water quality measurement result of the groundwater. .. Equipped with an ozone concentration measuring unit
The control unit adjusts the concentration of ozone gas generated by the ozone generator based on the measurement result of the ozone gas concentration injected into the ground water measured by the ozone concentration measuring unit or the measurement result of the ozone gas concentration recovered from the ground water. The purification device according to any one of claims 1 to 3, wherein the purifying device is characterized in that. In a purification method that purifies groundwater using sparging wells that are inserted into the soil
The first step to generate ozone gas with an ozone generator,
The second step of introducing the sustainer that suppresses the autolysis of ozone gas into the sparging well, and
A third step of measuring the pressure of the fluid at the outlet of the ozone generator and the pressure of the fluid at the inlet of the sparging well, and
When the pressure of the fluid at the outlet of the ozone generator is smaller than the pressure of the fluid at the inlet of the sparging well, the valve installed on the outlet side of the ozone generator is opened and the ozone generator is used. The fourth step of introducing the generated fluid into the sparging well, and
A purification method characterized by containing. The purification method according to claim 5, wherein each step is switched based on the measurement result of the ozone gas concentration injected into the groundwater or the ozone concentration of the gas recovered from the groundwater.

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