JP2020131136A - Anaerobic water flowing system and water flowing anaerobic bio system - Google Patents

Abstract

To provide an anaerobic water flowing system for use in a water flowing anaerobic bio system for an efficient clarification of soil and groundwater contaminated with volatile organic chlorine compound, and a method of using the system.SOLUTION: The anaerobic water flowing system is provided that removes volatile organic chlorine compound from water contaminated with the volatile organic chlorine compound containing an anaerobic microorganism which decomposes volatile organic chlorine compound (VOCs). The system includes: an aerator for vaporizing the volatile organic chlorine compound by an aeration treatment of the water contaminated with volatile compound; a deoxidizing device which contains deoxidant for adsorbing and removing oxygen from the gas used in the aeration treatment; a clarification device for adsorbing and removing the volatile organic chlorine compound vaporized by the aeration treatment; and a gas transfer device for transferring and circulating the gas recovered from the clarification device to the aerator.SELECTED DRAWING: Figure 2

Description

The present invention relates to an anaerobic water flow system for efficiently purifying soil and groundwater contaminated with volatile organochlorine compounds, and a water flow anaerobic biosystem using the anaerobic water flow system.

Tetrachlorethylene, trichlorethylene, and dichloroethylene, which are volatile organochlorine compounds, are used for degreasing / cleaning of metals, cleaning for dry cleaning, refrigerants, etc., and have high industrial utility value, but for the human body, liver damage, renal damage, etc. It becomes a harmful substance that causes. Therefore, soil and groundwater pollution caused by these organochlorine compounds has become a serious social problem.

There are many technologies for decomposing these organochlorine compounds and purifying contaminated soil and groundwater, one of which is a purification method by pumped storage aeration treatment. In this method, contaminated groundwater is pumped up, the volatile organic chlorine compounds contained in the groundwater are vaporized by aeration treatment, and the vaporized volatile organic chlorine compounds are adsorbed on activated carbon and removed. This is a method of purifying contaminated groundwater (for example, Patent Document 1).

Another technique has been developed to purify contaminated soil and groundwater by reductive dechlorination with anaerobic microorganisms (bioremediation). This method is a method of purifying contaminated soil and groundwater by substituting chlorine of an organochlorine compound with hydrogen using anaerobic microorganisms present in contaminated soil and groundwater (for example, Patent Document 2 or 3).

In addition, by combining these technologies, volatile organic chlorine compounds are vaporized by aeration treatment, and while the vaporized volatile organic chlorine compounds are adsorbed on activated carbon and removed, they are reductively dechlorinated by anaerobic microorganisms. A method for promoting purification by the present invention has also been developed by the inventors of the present application (Patent Document 4).

Japanese Unexamined Patent Publication No. 2003-154356 Japanese Unexamined Patent Publication No. 10-216694 Japanese Unexamined Patent Publication No. 2000-263032 Japanese Patent No. 4821097

Obayashi Technical Research Institute Bulletin No.73 2009 Journal of Environmental Biotechnology Vol. 13, No. 1, 13-18, 2013 Nature Biotechnology vol 23 no.10, 2005

As described in Patent Document 4, the inventors of the present application add nitrogen gas to perform anaerobic aeration without deteriorating the activity of anaerobic degrading bacteria in the pumped groundwater, and volatile organic compounds in the groundwater. We have developed a technology to remove chlorine compounds (VOCs) and inject groundwater containing anaerobic degrading bacteria into the ground again to promote anaerobic decomposition of VOC contamination. However, since air (oxygen) invades from the outside during aeration, obligate anaerobic bacteria such as Dehalococcoides bacteria that decompose dichloroethylene (DCE) and vinyl chloride (VC) are damaged during aeration treatment. (Non-Patent Documents 1 to 3). Therefore, in order to recycle the waste gas used for the aeration treatment, it is necessary to continuously add nitrogen gas to suppress the oxygen concentration. A certain amount of exhaust gas must be released to the atmosphere by adding nitrogen gas, and anaerobic aeration by adding nitrogen gas requires a control system for additional addition of nitrogen gas and emission of exhaust gas. It was.

As a result of diligent research, the inventors of the present application have newly found that an aeration gas can be deoxidized with an oxygen scavenger containing an oxygen scavenger in order to eliminate the need for additional addition of nitrogen gas and control for emission of exhaust gas. It was. In particular, by installing the deoxidizer immediately after aeration, oxygen was efficiently removed, which succeeded in simplifying the control of the aeration gas.

Therefore, the invention of the present application is the following [1] to [3A].
[1] An anaerobic water flow system that removes the volatile organic chlorine compounds from water contaminated with the volatile organic chlorine compounds, which contains anaerobic microorganisms that decompose volatile organic chlorine compounds (VOCs). ,
An aeration device for aerating water contaminated with the volatile organic chlorine compound to vaporize the volatile organic chlorine compound.
An oxygen scavenger containing an oxygen scavenger for removing oxygen from the gas used for the aeration treatment, and
A purification device for adsorbing and removing the volatile organic chlorine compound vaporized by the aeration treatment, and
A gas transfer device that transfers and circulates the gas recovered from the purification device to the aeration device, and
Anaerobic water flow system, including.
[2] The anaerobic water flow system according to claim 1, further comprising a gas-liquid separation device for removing water from the hydrated aeration gas by the aeration treatment.
[3] The anaerobic water flow system according to [2], wherein the oxygen scavenger contains iron powder.
[4] The anaerobic water flow system according to any one of [1] to [3], wherein the purification device contains activated carbon.

[5] A water-permeable anaerobic biosystem for purifying soil containing soil and groundwater contaminated with volatile organic chlorine compounds (VOCs).
(A) An intake well for taking in water contaminated with volatile organic chlorine compounds, which contains anaerobic microorganisms that decompose volatile organic chlorine compounds from the contaminated ground;
(B) The anaerobic water flow system according to any one of [1] to [4]; and (C) the water from which the volatile organic chlorine compounds have been removed by the anaerobic water flow system is used as the ground. Includes water injection well for return
The intake well (A) is provided on the downstream side of the groundwater flowing through the ground, and the water injection well (C) is provided on the upstream side.
The above water flow anaerobic biosystem.
[6] Further (6) anaerobic to the water injection well together with water from which the volatile organic chlorine compound has been removed from the decomposition accelerator storage tank, which includes a decomposition accelerator storage tank for storing the anaerobic microbial decomposition accelerator. The water flow anaerobic biosystem according to [5], wherein the microbial decomposition accelerator is injected.

[1A] From water contaminated with volatile organic chlorine compounds containing anaerobic microorganisms that decompose volatile organic chlorine compounds (VOCs), by oxygen of anaerobic microorganisms that decompose volatile organic chlorine compounds (VOCs) It is a method of recovering water from which the volatile organic chlorine compounds have been removed while suppressing damage.
The contaminated water is poured into the aeration device and
Step 1) Aeration treatment is performed to vaporize the volatile organic chlorine compound.
Step 2) Oxygen is removed by passing the aeration gas used for the aeration treatment through an oxygen scavenger containing an oxygen scavenger.
Step 3) Arbitrarily, the aeration gas from which oxygen has been removed is passed through a gas-liquid separator to remove water.
Step 4) The volatile organic chlorine compound vaporized by the aeration treatment is adsorbed and removed through a purification device.
Step 5) The aeration gas from which the oxygen and the volatile organic chlorine compound have been removed is circulated and transferred to the aeration device using a gas transfer device.
By repeating steps 1) to 5)
Perform anaerobic aeration,
A method for recovering water from which the volatile organic chlorine compound has been removed.

[2A] A method for purifying soil containing soil and groundwater contaminated with volatile organic chlorine compounds (VOCs).
Step A) Water contaminated with volatile organic chlorine compounds containing anaerobic microorganisms that decompose volatile organic chlorine compounds is recovered from the intake well installed in the contaminated ground.
Step B) The water from which the volatile organic chlorine compound has been removed is recovered by the method described in [1A].
Step C) Including water injection into a water injection well for returning the water from which the volatile organic chlorine compounds have been removed to the ground.
The above method, wherein the intake well is provided on the downstream side of the groundwater flowing in the ground, and the water injection well is provided on the upstream side of the groundwater flowing in the ground.
[3A] The method according to [2A], wherein in step C), an anaerobic microbial decomposition accelerator is injected together with water from which the volatile organic chlorine compound has been removed.

According to the present invention, anaerobic aeration by adding nitrogen gas becomes unnecessary, and it is possible to simplify the system for controlling the gas. In addition, since 100% of the deoxidized gas is recovered, the deoxidizing treatment can proceed quickly, the growth of aerobic microorganisms is suppressed during the aeration treatment, and the damage of anaerobic microorganisms that decompose volatile organic chlorine compounds is damaged. It has become possible to reduce the adverse effects on biostimulation when the groundwater is returned to the ground thereafter.
In addition, the oxygen scavenger itself containing the oxygen scavenger has a VOC adsorption / removal action, and also has the effect of a conventional purification device for adsorbing / removing volatile organic chlorine compounds, so that it is more efficient. , It has become possible to remove volatile organic chlorine compounds.

It is a figure which showed the reduction dechlorination reaction of an organic chlorine compound by an anaerobic microorganism and the product thereof together with the reaction process. It is a figure which shows the structure of the anaerobic water flow system described as one Example of this invention. It is a figure which shows the structure of the water flow anaerobic biosystem which is described as one Example of this invention. Schematic diagram of the anaerobic aeration experimental device according to Example 1. It is a figure which shows the influence of anaerobic aeration and aerobic aeration at 30 degree on VOC decomposition by an anaerobic microorganism. It is a figure which shows the influence of anaerobic aeration and aerobic aeration at 35 degree on VOC decomposition by an anaerobic microorganism.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not necessarily limited thereto. The object, feature, advantage, and idea thereof of the present invention will be apparent to those skilled in the art from the description of the present specification, and those skilled in the art can easily reproduce the present invention from the description of the present specification. it can. The embodiments and specific examples of the invention described below show preferred embodiments of the present invention, and are shown for illustration or explanation, and the present invention is described in them. It is not limited. It will be apparent to those skilled in the art that various modifications and modifications can be made based on the description of the present specification within the intent and scope of the present invention disclosed in the present specification.

Anaerobic water flow system One aspect of the present invention is to remove the volatile organic chlorine compound from water contaminated with the volatile organic chlorine compound, which contains anaerobic microorganisms that decompose volatile organic chlorine compounds (VOCs). An anaerobic water flow system that aerates water contaminated with the volatile organic chlorine compound to vaporize the volatile organic chlorine compound, and oxygen from the gas used for the aeration treatment. A deoxidizer containing a deoxidizing agent for removing the gas, a purifying device for adsorbing and removing the volatile organic chlorine compound vaporized by the aeration treatment, and the aeration device for the gas recovered from the purifying device. An anaerobic water flow system, including a gas transfer device that transfers and circulates to. It is preferable that the aeration device, the oxygen scavenger device, the purification device, and the gas transfer device are connected in this order through the pipeline.
The anaerobic water flow system may further include a gas-liquid separator for removing water from the hydrated aeration gas by aeration treatment. In such a case, it is preferable that the aeration device, the oxygen scavenger device, the gas-liquid separation device, the purification device, and the gas transfer device are connected in this order through a pipeline.
In an anaerobic water flow system, the oxygen scavenger may contain iron powder.
In an anaerobic water flow system, the purification device may contain activated carbon.

Water flow anaerobic biosystem One aspect of the present invention is a water flow anaerobic biosystem for purifying soil containing soil and groundwater contaminated with volatile organic chlorine compounds (VOCs), and (A) the above-mentioned contaminated. With an intake well for taking in water contaminated with volatile organic chlorine compounds, which contains anaerobic microorganisms that decompose volatile organic chlorine compounds; (B) with the above-mentioned anaerobic water flow system; (C) The intake well (A) is provided on the downstream side of the groundwater flowing through the ground, including a water injection well for returning the water from which the volatile organic chlorine compound has been removed by the anaerobic water flow system to the ground. It is a water flow anaerobic biosystem in which the water injection well (C) is provided on the upstream side.
The water flow anaerobic biosystem may further include a decomposition accelerator storage tank for storing the anaerobic microbial decomposition accelerator, and the water injection well together with water from which the volatile organic chlorine compound has been removed from the decomposition accelerator storage tank. An anaerobic microbial decomposition accelerator may be injected into the well.

"Volatile organic chlorine compounds (VOCs)" refer to highly volatile organic chlorides. Although not particularly limited, tetrachlorethylene (PCE), trichlorethylene (TCE), dichloroethylene (cis or trans-DCE) and the like are included.

The "anaerobic microorganism that decomposes volatile organic chlorine compounds (VOCs)" refers to a microorganism that can grow under anaerobic conditions and decomposes volatile organic chlorine compounds (VOCs). Although not particularly limited, bacteria of the genus Dehalobacter, Dehalococcoides, Desulfuromonas, Desulfuromonas, Geobacter, Sulfurospirillum, Clostridium and the like can be mentioned. In particular, it preferably contains the genus Dehalococcoides, which decomposes obligately anaerobic bacteria, dichloroethylene (DCE) and vinyl chloride (VC) (FIG. 1).

"Aeration treatment" refers to blowing a gas into a liquid (aeration), and "aeration device" refers to a device for that purpose. In the technical field, it includes those used as an aeration tank and an aeration tank. The "aeration device" includes the following "oxygen scavenger containing oxygen scavenger", "gas-liquid separation device", "purification device for adsorbing and removing volatile organic chlorine compounds" and "gas transfer" via a pipeline. The "device" may be connected, and may include an aeration device for aeration, in which case the aeration device is preferably connected to a gas transfer device.

"Oxygen scavenger" refers to a substance that adsorbs and removes oxygen. Although not particularly limited, iron (iron powder, iron sponge, iron foil, iron rod, etc.), glucose and glucose oxidase, reductone (vitamin C) and the like are preferable. Examples of the "deoxidizer containing an oxygen scavenger" include, but are not limited to, a column containing an oxygen scavenger.
The "gas used for aeration treatment" is deoxidized by circulating through a "deoxidizer containing an oxygen scavenger" even if it is air at the time of manufacturing the anaerobic water flow system according to the present invention.

The "gas-liquid separation device" is preferably a device having a function of separating gas and liquid, for example, a device provided with a gas-liquid separation membrane or the like, a column filled with glass beads, or the like. By such a device, only gas is sent to the "purification device for adsorbing and removing volatile organic chlorine compounds", and the volatile organic substances included in the following "purification device for adsorbing and removing volatile organic chlorine compounds". Prevents substances that adsorb and remove chlorine compounds from absorbing water. When the above-mentioned "oxygen scavenger containing an oxygen scavenger" absorbs water, it may also have a function as a "gas-liquid separator".

The "purification device for adsorbing and removing volatile organic chlorine compounds" refers to a device containing a substance that adsorbs and removes vaporized volatile organic chlorine compounds contained in aeration gas, and activated carbon is preferable as such a substance, for example. The device may include a gas separation membrane such as a ceramic separation membrane. With such a device, the aerated gas can be detoxified and reused.

The "gas transfer device" refers to a device for transferring the detoxified aeration gas to the aeration device again and using it for aeration treatment. A compressor or the like corresponds to this, and it is possible to enable aeration as it is by increasing the pressure and sending it to the aeration device in the aeration device. Although not particularly limited, the "gas transfer device" is preferably installed downstream of the above-mentioned "oxygen scavenger-containing deoxidizer" and "purification device" in order to prevent deterioration due to volatile organic chlorine compounds and humidity. ..

"Aerobic microbial decomposition accelerator" is a hydrogen donor in a reductive dechlorination reaction that replaces chlorine and hydrogen in a volatile organochlorine compound, or iron that affects hydrogen by reaction with water (iron powder, iron). Sponge, iron foil, iron rod, etc.). Examples of the hydrogen donor include, but are not limited to, alcohols such as methanol or ethanol, low molecular weight organic substances such as glucose or sucrose, lower fatty acids such as acetic acid, propionic acid, lactic acid, or butyric acid, or polylactic acid esters. There are certain HRCs (Hydrogen Release Compounds), gluconic acid and gluconate salts, gluconic acid amides, gluconic acid esters, gluconic acid derivatives such as gluconic acid anhydride, and the like.

One aspect of the "anaerobic water flow system" according to the present invention is, as shown in FIG. 2, an aeration device (1), a deoxidizer (2), a gas-liquid separation device (3), a purification device (4). , And the gas transfer device (5) may be included. These may be connected via a pipeline to form a closed circuit. When the oxygen scavenger (2) absorbs water, the gas-liquid separator (3) may not be included.
The aeration device (1) has a pipe for injecting water contaminated with volatile organic chlorine compounds (hereinafter, "contaminated water") and water from which volatile organic chlorine compounds have been removed (hereinafter, "contamination-removed water"). ) Has a pipe to drain. Water injection and drainage may be performed with one pipe.
The contaminated water is injected into the aeration device (1), and the aeration treatment is performed by the aeration gas. The aeration gas after the aeration treatment contains oxygen mixed during injection of contaminated water and vaporized volatile organic chlorine compounds, and also contains humidity. When such a gas is passed through the oxygen scavenger (2), the mixed oxygen is efficiently absorbed due to its high humidity. In addition, the vaporized volatile organochlorine compounds themselves are partially absorbed. Therefore, the depletion of the purification device (4) is prevented.

The aerated gas containing humidity after passing through the oxygen scavenger (2) passes through the gas-liquid separator (3) in order to remove water. By such a treatment, the consumption of the purification device (4) is suppressed. The separated water may be returned to the aeration device (1). At that time, it may be returned to the aeration device (1) by another pipe without passing through the deoxidizer (2).

By passing the aeration gas from which the water has been removed through the purification device (4), the vaporized volatile organic chlorine compound contained in the aeration gas is absorbed and removed.

The aerated gas that has passed through the purification device (4) is returned to the aeration device (1) by the gas transfer device (5) for reuse.

By such aeration gas circulation, volatile organic chlorine compounds are absorbed and removed from the contaminated water. Since the aerated gas is maintained in an anaerobic state, damage to obligate anaerobic bacteria that decompose volatile organic chlorine compounds (VOCs) contained in contaminated water is suppressed.
Therefore, by returning the decontaminated water from which the volatile organic chlorine compounds have been removed by the "anaerobic water flow system" according to the present invention to the ground, biostimulation of the contaminated ground (volatile organic chlorine compounds (VOCs) by microorganisms). (Decomposition) is promoted.

As shown in FIG. 3, one aspect of the "water flow anaerobic biosystem" according to the present invention is to use contaminated water collected from an intake well installed in the ground contaminated with volatile organic chlorine compounds (VOCs). Volatile organic chlorine compounds (VOCs) are removed by treatment with the "anaerobic water flow system" according to the present invention, and the removed water is returned to the water injection well to allow the in-situ anaerobic bio of contaminated ground. Stimulation is promoted.
Alternatively, by providing an intake well in the ground where many anaerobic microorganisms that decompose VOCs are present and installing a water injection well in the ground where there are no or few anaerobic microorganisms that decompose VOCs, anaerobic microorganisms that decompose VOCs can be used. It can promote biostimulation of non-existent or less contaminated ground.
At that time, an anaerobic microbial decomposition accelerator is injected into the water injection well together with the water from which the volatile organic chlorine compound has been removed, by an option. Such treatment further promotes biostimulation of contaminated ground.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1: Anaerobic aeration experiment using an iron powder column In order to maintain an anaerobic state, oxygen in the aeration gas is removed by passing through iron powder, which is an oxygen scavenger, and VOC is removed by passing through activated carbon. , Again, verified whether it can be recycled.

1. 1. Test Method (1) Preparation of Iron Powder Column Tank The iron powder column tank (hereinafter referred to as Table 1) shown in Table 1 using the reagent iron powder (<150 μm; 090-04781; CAS.NO439-89-6) manufactured by Wako Pure Chemical Industries, Ltd. Iron powder tank) was prepared.

(2) Test equipment (Fig. 4)
Air exposure tank: 3L volume (inner diameter 10cm, height 40cm, cylinder) (trichlorethylene solution 2L, add trichlorethylene reagent to tap water)
Trichlorethylene concentration: 1 mg / L
Aeration amount: 1 L / min Oxygen concentration meter: JICKO OXY-1-M
Gas-liquid separation tank: Plastic column filled with glass beads (inner diameter 5 cm, length 20 cm)
Activated carbon tank: Contains 1000 g of granular activated carbon (Wako Pure Chemical Reagent)

2. 2. Results (1) Oxygen concentration In order to see the effect of deoxidization at the installation position of the iron powder tank (oxygen scavenger), in the case where the iron powder tank was installed immediately after the aeration tank and the case where it was installed immediately after the gas-liquid separation tank. , The time change of oxygen concentration was investigated.
The oxygen concentration was measured with an oxygen concentration meter (OXY-1-M, manufactured by Ichinenjiko Co., Ltd.). When the iron powder tank was installed immediately after the aeration tank, the oxygen concentration was 0.5% or less in about 20 minutes. On the other hand, when installed immediately after the gas-liquid separation tank, the oxygen concentration could only drop to about 14% even after a long period of time (Table 2). Humidity must be sufficiently high to sufficiently reduce the oxygen concentration.

(2) VOC concentration in exhaust gas The VOC concentration immediately after aeration was measured using a detector tube (manufactured by Gastec, 132M, 132LL). Immediately after passing through the iron powder column, the concentration decreased by 85%. Furthermore, after passing through the activated carbon tank, it became almost zero (Table 3).

(3) VOC concentration in solution The VOC concentration in solution was measured by the headspace method (analytical instrument is JEOL GC-8610 PID detector). After 1 hour (total aeration volume 60 L), the VOC concentration became almost 0 (Table 4).

Example 2: Effect of oxygen during aeration As the VOC-degrading bacterial solution, a degrading bacterial solution culture solution containing Dehalococcoides bacteria obtained by subculturing groundwater collected from a site in Kanagawa Prefecture with trichlorethylene and chloroclin (registered trademark) was used. ..
1. 1. Test method (1) Aeration method Aeration time: 6 hours Aeration water volume (VOC-degraded bacterial solution culture solution): 2 L
Amount of air exposure: 1 L / min Temperature control: An air exposure device was placed in a constant temperature layer, and temperature control (temperature: 30 ° C. and 35 ° C.) was performed.
For anaerobic exposure, deoxidized air was used as in Example 1. For aerobic aeration, air that neither deoxidizes nor circulates exhaust gas was used.

(2) Room temperature decomposition experiment Add aerated decomposed bacterial solution to a 130 mL medium bottle, tap water, microbial nutrient [chlorocrine (registered trademark) (soda gluconate 93%, urea 6%, potassium dihydrogen phosphate) 1%)], a tochloroethylene (TCE) solution was added at the ratio shown in Table 6, and curing was performed at room temperature. The liquid in the medium bottle was sampled and measured by the headspace method using a gas chromatograph (PID detector).

2. 2. Results The results are shown in FIGS. 6 and 7. At 30 ° C., in the case of anaerobic aeration using air from which oxygen was removed by iron powder, the decomposition was extremely fast at about 10 days, whereas in the case of aerobic aeration, it was significantly delayed at about 30 days. Similarly, at 35 ° C., in the case of anaerobic aeration, the decomposition was completed in about 20 days, whereas in the case of aerobic aeration, it took about 40 days, which was more than double the time, and the delay was large. Therefore, it was found that aeration with air from which oxygen by iron powder has been removed has an effect of enhancing the decomposition of TCE by anaerobic bacteria.

(1) Air exposure device (2) Deoxidizer (3) Gas-liquid separation device (4) Purification device (5) Gas transfer device (6) Decomposition accelerator storage tank

Claims (6)

An anaerobic water flow system that removes the volatile organochlorine compounds from water contaminated with the volatile organochlorine compounds, which contains anaerobic microorganisms that decompose volatile organochlorine compounds (VOCs).
An aeration device for aerating water contaminated with the volatile organic chlorine compound to vaporize the volatile organic chlorine compound.
An oxygen scavenger containing an oxygen scavenger for removing oxygen from the gas used for the aeration treatment, and
A purification device for adsorbing and removing the volatile organic chlorine compound vaporized by the aeration treatment, and
A gas transfer device that transfers and circulates the gas recovered from the purification device to the aeration device, and
Anaerobic water flow system, including. The anaerobic water flow system according to claim 1, further comprising a gas-liquid separation device for removing water from the hydrated aeration gas by the aeration treatment. The anaerobic water flow system according to claim 1 or 2, wherein the oxygen scavenger contains iron powder. The anaerobic water flow system according to any one of claims 1 to 3, wherein the purification device contains activated carbon. A water-permeable anaerobic biosystem for purifying soil and groundwater contaminated with volatile organochlorine compounds (VOCs).
An intake well for taking in groundwater contaminated with the volatile organic chlorine compound, which contains an anaerobic microorganism that decomposes the volatile organic chlorine compound from the contaminated ground.
The anaerobic water flow system according to any one of claims 1 to 4,
A water injection well for returning the water from which the volatile organic chlorine compounds have been removed by the anaerobic water flow system to the ground,
Including
The intake well is provided on the downstream side of the groundwater flowing in the ground, and the water injection well is provided on the upstream side of the groundwater flowing in the ground.
The above water flow anaerobic biosystem. Includes a degradation accelerator storage tank for storing anaerobic microbial degradation accelerators,
The water flow anaerobic biosystem according to claim 5, wherein the anaerobic microbial decomposition accelerator is injected into the water injection well together with water from which the volatile organic chlorine compound has been removed from the decomposition accelerator storage tank.

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