JP2002210453A - Method for purifying soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for purifying soil by which action of a microorganism is promoted and whole soil to be purified is uniformly purified when organic matter contained in the soil to be purified is removed by using the microorganism. SOLUTION: The method for purifying soil in which the organic matter contained in the soil to be purified 1 is removed by using the microorganism comprises a sucking process for sucking water in voids between soil in the soil to be purified 1, an adsorbing process in which the water in voids between soil sucked in the sucking process is brought into contact with an adsorbent 52 for adsorbing an inhibitor inhibiting the removal of the organic matter by the microorganism and a supply process in which the water in voids between soil brought into contact with the adsorbent 52 in the adsorbing process is supplied to the soil to be purified 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soil purification method, and more particularly to a soil purification method for removing organic substances contained in soil to be purified using microorganisms capable of decomposing the organic substances.

[0002]

2. Description of the Related Art Conventionally, in this type of soil purification method, particularly when organic matter is to be decomposed and removed from contaminated soil in a state in which water such as groundwater is filled in a soil gap, in order to eliminate oxygen deficiency, A pipe for injecting air or an air diffuser is buried in the inside of the soil or below the soil, and air containing oxygen is supplied from the pipe into the soil. However, according to the above-mentioned conventional soil purification method, the oxygen-containing air bubbles released from the pipes and the air diffusers do not diffuse much in the horizontal direction, and a relatively large-diameter soil gap that is easy to enter. And even if air is supplied from inside or below the soil, it is difficult to supply oxygen uniformly over the entire soil to be purified. However, there is a problem that it is difficult to efficiently decompose the organic matter by the above method.

[0003] In order to solve the above-mentioned problems, the inventors of the present invention have secured a passage through which a gas containing oxygen or a liquid in which oxygen is abundantly dissolved is widely distributed in the soil gap, and the soil to be purified is As a method of distributing oxygen over the whole, in the soil purification method having a suction step of sucking soil pore water in the soil to be purified, or in the soil purification method, the soil gap further sucked in the suction step A soil purification method having a supply step of adding oxygen to water and resupplying the soil to be purified has been proposed. According to this soil purification method, in the suction step of sucking the soil pore water in the soil to be purified, the suction is performed so that the suction speed of the soil pore water is increased as compared with the movement of the soil pore water such as the groundwater. Thereby, a negative pressure is formed in the soil gap, air and water containing oxygen rich from the surface and other areas of the soil penetrate into the soil gap, and the oxygen supply water is positively supplied to the soil gap. Oxygen could be supplied uniformly over the entire soil to be supplied and purified. Further, in the supplying step, oxygen is added to the soil pore water sucked in the suction step and supplied to the purification target soil in which the negative pressure is generated, whereby the oxygen supply water is positively supplied to the soil gap. To supply oxygen uniformly over the entire soil to be purified.

[0004]

However, even if the above-mentioned soil purification method proposed by the present inventors is used,
There is a problem that the decomposition of the organic matter in the purification target soil may progress relatively slowly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned drawbacks, and when removing organic substances contained in a soil to be purified using microorganisms, promote the activity of microorganisms and uniformly purify the entire soil to be purified. It is to provide a purification method.

[0006]

According to a first aspect of the present invention, there is provided a soil purification method comprising the steps of: removing organic matter contained in a soil to be purified;
In a soil purification method for removing using microorganisms, a suction step of sucking soil pore water in the soil to be purified, and inhibiting the soil pore water sucked in the suction step from inhibiting removal of the organic matter by the microorganism. The present invention is characterized in having an adsorption step of bringing a substance into contact with an adsorbent for adsorbing a substance, and a supply step of supplying the soil pore water brought into contact with the adsorbent in the adsorption step to the purification target soil.

[0007] In the above-mentioned characteristic means, it is preferable that the method further comprises an oxygen addition step of adding oxygen to the soil pore water. Preferably, the substance is naphthalene or a derivative thereof, as described in claim 4, the adsorbent is preferably activated carbon, and as described in claim 5, the soil to be purified is Processing in situ is preferred. And these effects are as follows.

The inventors of the present application have intensively studied various factors regarding the mechanism of inhibiting the decomposition of organic substances by microorganisms in the application example in which the decomposition of organic substances in the soil to be purified is relatively slow. As a result, the purification target soil contains an inhibitory substance that inhibits the removal of the organic matter by the microorganism, and in particular, when the inhibitory substance is eluted into the soil pore water, organic matter decomposition by the microorganism is suppressed. It will be clear.

More specifically, when the above-described soil purification method proposed by the present inventors is applied to the soil to be purified in which the inhibitor is eluted, the soil pore water sucked from the soil to be purified is reused. Since the microorganisms are supplied to the purification target soil, the microorganisms are repeatedly exposed to the soil pore water from which the inhibitor has been eluted. Then, it is considered that even if the supply of oxygen is sufficiently performed, the activity of the microorganism is inhibited or killed, and the decomposition of the organic matter is difficult to progress. Therefore, the inventors of the present application have conducted intensive studies to avoid such an inhibition mechanism, and as a result, have come to the present invention.

That is, as described in claim 1,
In a soil purification method for removing organic substances contained in the soil to be purified using microorganisms, if a suction step of sucking soil pore water in the soil to be purified is provided, compared with the movement of soil pore water such as the groundwater. By sucking so that the suction speed of the soil pore water is increased, a negative pressure is generated based on the difference between the volume of the soil pore water sucked and the volume of the soil pore water that has entered from another region due to movement, and Fluid (liquid, gas) in the gap between the soils to be purified
Can be facilitated to flow from a distance toward the suction point. Then, in the supply step, the soil pore water sucked in the suction step is supplied again to the soil to be purified, so that the soil pore water is positively applied to the soil gap where the negative pressure is formed in the suction step. And it can be made to flow more easily in the soil gap. In this way, by linking the suction step and the supply step, the soil pore water circulates in the soil gap of the soil to be purified. Here, unlike the air bubbles, the soil pore water flows in a direction in which a negative pressure is formed without being greatly affected by buoyancy, so that the soil pore water easily moves in the horizontal direction, and the soil to be purified is also removed. It can move all the way through the small gap.

Further, in the present method, an adsorption step is provided, and the soil pore water sucked in the suction step is brought into contact with an adsorbent for adsorbing an inhibitory substance which inhibits the removal of the organic matter by the microorganism. Therefore, the soil pore water from which the inhibitor has been removed can be returned to the purification target soil.

Therefore, with the movement of the soil pore water,
The inhibitory substance is moved out of the treatment target soil even from within the fine gap of the purification target soil, and the inhibitory substance is removed from the soil pore water by adsorbing the inhibitory substance on the adsorbent, and again. By supplying the substance to the treatment target soil, the inhibitor can be removed over the entire treatment target soil. Thereby, even when the inhibitor is a substance that exerts toxicity to microorganisms even if it is slightly eluted into soil pore water, organic substances can be decomposed by the microorganisms, and
Since it is not necessary to discard the soil pore water taken out from the purification target soil in the suction step, it is possible to reduce the construction and operation costs of the wastewater treatment facility.

Further, as described in claim 2, this soil pore water is enriched with oxygen by adding oxygen in the oxygen addition step, and flows through the soil to be purified.
A large amount of oxygen can be quickly supplied to a region where it has been difficult to carry oxygen by passing through a fine soil gap or a remote soil gap where it was difficult to transport oxygen, and to a region where oxygen supply was difficult. In particular, because the horizontal movement of soil pore water is facilitated, oxygen can be easily supplied to the deep part away from the ground surface and the area horizontally away from the suction point, so only air bubbles are supplied. Oxygen can be supplied to a region where it has been difficult to supply oxygen by a method such as aeration. At the same time, it is not necessary to separately procure water for oxygen supply, so that the water for oxygen supply can be collected,
Manufacturing and transportation costs can be reduced. In order to achieve the purpose of supplying the oxygen-enriched fluid, the oxygen addition step may be performed before the soil pore water is sucked from the purification target soil and re-supplied.

Further, the inventors of the present invention have proposed PAH (polycyclic aromatic hydrocarbon; polycyclic aromatic).
It has been found that creosote components, particularly naphthalene and derivatives thereof, contained in hydrocarbon have high solubility in water among PAHs and inhibit the activity of decomposing microorganisms that degrade PAH. Therefore, in the above characteristic means, when the inhibitor is naphthalene or a derivative thereof as described in claim 3, high microbial activity can be obtained by employing this method. The naphthalene derivative has a structure similar to that of the naphthalene and refers to a material having similar properties.
For example, methylnaphthalene, chloronaphthalene, nitronaphthalene, naphthalenesulfonic acid and the like can be mentioned.

Further, as described in claim 4,
It is preferable that the adsorbent is activated carbon because it can adsorb various inhibitors such as the naphthalenes.

Further, in particular, soil in which the soil gap is filled with water such as groundwater has a high specific gravity, and it is necessary to simultaneously remove the groundwater that springs out. When it is attempted to treat the existing soil to be purified, the labor and cost are enormous. Therefore, if the soil to be purified can be treated in situ as described in claim 5, the treatment of the soil to be purified can be performed quickly and at low cost.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an in-situ remediation facility for implementing a soil purification method according to the present invention.

The soil 1 to be purified in which this equipment is installed is:
The vicinity of the surface layer is the unsaturated soil 11 in which the soil gap is not saturated with moisture. In this region, oxygen supply in the soil gap is relatively easily performed. This unsaturated soil 1
In the lower layer of 1, there is a saturated soil 12 in which the soil gap is filled with groundwater. In this saturated soil 12 region, the movement of air in the soil gap hardly occurs due to the accumulation of water,
Organic substances are hardly decomposed by microorganisms.

The in-situ remediation equipment includes a recovery unit 2 (for example, a pipe or a well having a large number of pores) provided with a water intake unit (not shown) in the saturated soil 12, And a supply section 3 (for example, a pipe or a well with a large number of pores) provided with an injection section (not shown), which are provided separately in the soil 1 to be purified.

An adsorption tower 5 is provided between the recovery section 2 and the supply section 3, and a storage section 5 of the adsorption tower 5 is provided.
1 is provided with an adsorbent 52 that adsorbs an inhibitory substance that inhibits the growth of the microorganism and the activity of decomposing organic substances.

The collecting section 2 and the accommodating section 51 of the adsorption tower 5
Is connected to the adsorption tower 5 from the collection unit 2 by driving the pump P1 so that the soil pore water in the saturated soil 12 is conveyed. The storage section 51 and the supply section 3 are connected to the supply pipe 31.
, And by driving the pump P <b> 2, the collected liquid 52 (soil interstitial water) that has passed through the storage section 51 is injected into the supply section 3.

Further, the saturated soil 12 near the supply section 3 is provided with a ventilation section 4 into which air is injected from a pump P3.
(For example, a pipe having a large number of pores) is bored, and air (bubbles) is supplied to the saturated soil 12.

The same number of the recovery unit 2, the supply unit 3, and the ventilation unit 4 may be provided for the soil to be purified, but one of them may be provided at a higher ratio than the other. Often, these installation ratios and base numbers can be determined in consideration of soil quality, purification range, purification depth, and the like.

When the pump P 1 of the above-mentioned in-situ remediation facility is driven, the soil pore water (recovered liquid) in the saturated soil 12 is transferred to the adsorption tower 5 through the recovery pipe 21. Thereby, the saturated soil 12
The pressure in the soil gap is reduced as compared with other areas, and water easily flows in from other areas. On the other hand, the recovered liquid flows into the supply unit 3 from the adsorption tower 5 through the supply pipe 31 and is in a pressurized state as compared with other regions, and the recovered liquid easily permeates far from the supply unit 3. Become. Therefore,
As shown by the arrow in FIG.
, And flows in a substantially horizontal direction toward the collecting section 2. At this time, when air is supplied from the ventilation part 4 provided in the vicinity of the part 3, the water flow from the supply part 3 to the collection part 2 includes soil pore water collected from the collection part 2 and water. The recovered liquid having a higher dissolved oxygen concentration, that is, the water for oxygen supply flows, and the water for oxygen supply permeates over a wide range of the saturated soil 12. In this way, the soil pore water flowing in the saturated soil 12 becomes an oxygen carrier and reaches every corner of the soil gap, and the growth and activity of aerobic microorganisms existing in the saturated soil 12. Can be promoted, so that decomposition of organic substances by microorganisms is promoted.

Here, the recovered liquid passes through the adsorption tower 5 once and is supplied again to the supply section 3,
When passing through the adsorption tower 5, it comes into contact with the adsorbent 52 provided in the storage section 51. At this time, the inhibitor eluted in the soil pore water of the treatment target soil 1 is:
Adsorbed by the adsorbent 52. And the inhibitor 52
The recovered liquid from which is removed is re-supplied from the supply unit 3 to the purification target soil 1 as the oxygen supply water after enriched with oxygen, so that soil pore water is repeatedly circulated to the adsorption tower 5. Thereby, the concentration of the inhibitor in the soil pore water is reduced, whereby the growth, proliferation, organic matter decomposition activity and the like of the microorganism can be further enhanced, and the decomposition and removal of the organic matter to be purified can be promoted.

The permeation range and speed of the oxygen supply water can also be adjusted by increasing the installation area of the water intake section and the injection section or by adjusting the installation length in the vertical direction.

The microorganisms may be indigenous, but the introduction of microorganisms having a high ability to decompose organic substances to be removed from the outside further promotes the decomposition of organic substances more efficiently. As a method of introducing the microorganisms, it may be spread on the ground surface and wait for migration to the saturated soil 12,
From the supply part 3 and the ventilation part 4, it may be sent to the saturated soil 12 together with the recovered liquid and air. In this case, the microorganism to be added can be arbitrarily selected in relation to the organic substance to be decomposed. For example, microorganisms that have a high rate of decomposition of organic substances to be degraded, microorganisms that exhibit resistance to organic substances to be decomposed at a concentration that inhibits the growth of general microorganisms, and microorganisms that promote the decomposition of organic substances in cooperation with other microorganisms are suitable. In addition, not only one kind but also a plurality of kinds can be mixed or added sequentially according to the purification treatment stage.

The supply of the oxygen-supplying liquid may be continuously performed to form a circulation cycle at all times. However, if the oxygen demand is not so high as to require continuous circulation, When the dissolution rate of the inhibitor is low, the operating cost can be reduced by intermittently circulating the soil pore water. Note that it is preferable that the supply step be performed while the negative pressure in the soil gap generated by performing the suction step exists, because the movement of the oxygen supply water is promoted.

Further, the soil to be purified may be excavated and charged into a reactor. However, considering that the specific gravity of the soil to be purified is large due to the large amount of water such as groundwater and the problem of treatment of the groundwater that has been spouted, it is efficient to perform organic matter decomposition in situ without excavation. It is preferable because it is a target.

Further, the recovered liquid 52 is mixed with the saturated soil 1
When the nutrients preferred by the microorganisms that decompose the organic matter to be removed are supplied at the time of re-supply to 2, the decomposition effect by the microorganisms is increased.

[0031]

EXAMPLES Examples of the present invention will be described below by exemplifying a case in which an organic substance to be removed by purification is tar, and naphthalenes (naphthalene and derivatives thereof) contained in the tar are inhibitors. This will be described with reference to the drawings.

A soil to be purified (tar-impregnated soil) containing artificially containing tar containing a large amount of naphthalenes is prepared.
Mixture 62 of this tar impregnated soil and tar degrading microorganisms
Out of the container 61, as shown in FIG.
And housed in the housing part 61 of the column 6 having a pressure-tightness. The accommodating part 61 has 80 to 100 μm
Filters 63, 63 made of sintered stainless steel having a pore diameter of
From leaking from Further, an adsorption column 7 filled with 10 g of activated carbon 71 as an adsorbent is provided, and a water pipe 8
1, 82, and connected to the water pipe 8 by the liquid pump P3.
An air supply pipe 9 is connected to the water supply pipe 81 that connects the adsorption column 7 and the lower end of the storage section 61 while forming an aqueous solution circulation path that circulates the aqueous solution in the first and second pumps 82. An oxygen supply path was formed. In this way, an in-situ bioremediation and experimental system simulating a non-slurry soil treatment system in which the soil to be purified was accommodated in a reactor was constructed and subjected to the experiments described below.

Experimental Example 1 An aqueous solution containing 0.1% K ₂ HPO ₄ and 0.1% NH ₄ NO ₃ as nutrients (hereinafter referred to as an NP medium) was passed through the aqueous solution circulation path. The NP medium was infiltrated in the direction of moving from the lower part to the upper part in the storage part 61 of the column 6, and the soil gap of the tar-impregnated soil was filled with the NP medium.

The liquid feed pump P3 is driven to move 2.0 mL /
The NP medium was supplied at a flow rate of 1 minute. The NP culture medium released from the storage section 61 is sent to the adsorption column 7 through the water supply pipe 82, where it is brought into contact with the activated carbon 71 provided in the adsorption column 7, and
1 and was again supplied to the storage section 61 of the column 6.
At this time, the air pump P4 is not driven,
The above-mentioned operation can be said to be a washing operation for mainly removing the substance adsorbed on the activated carbon from the mixture 62.

After the above-described washing operation was continued for 7 days, the mixture 62 was taken out of the column 6 and 5,000 rpm.
m and centrifuged for 10 minutes to perform solid-liquid separation. 12 g of the separated solid (the mixture 52) and 20 mL of the NP medium
The mixture was placed in a 00 mL Erlenmeyer flask, sealed with a breathable cotton plug, and cultured with shaking at 30 ° C. and 175 rpm for 12 weeks (slurry treatment). At the start of culture and from the start of culture,
The residual amount of tar in the tar-impregnated soil after 2, 4, 8, and 12 weeks was monitored by measuring the concentration of the main component, PAH. The PAH concentration was measured as follows. The collected tar-impregnated soil was air-dried in a fume hood for at least two days. The air-dried tar-impregnated soil is pulverized, 2 mL of acetonitrile is added to 1 g of the tar-impregnated soil, and the resultant is subjected to a water bath at 60 ° C. for 30 minutes, and then centrifuged at 3000 rpm for 10 minutes to obtain the tar-impregnated soil. The supernatant was analyzed by HPLC. The result is shown in FIG. The substance adsorbed on the activated carbon 71 was extracted by a toluene-Soxhlet extraction method, and the amount and type of PAH adsorbed on the activated carbon were analyzed by HPLC. The result is shown in FIG.

[Comparative Example 1] For comparison, 12 g of the mixture not subjected to the above-mentioned washing operation and the NP medium were placed in a 300 mL Erlenmeyer flask, and sealed with a breathable cotton stopper. Shaking culture was performed at 30 ° C. and 175 rpm for 12 weeks. At the start of culture and from the start of culture
The remaining amount of tar in the tar-impregnated soil after 4, 8, and 12 weeks was monitored by measuring the concentration of PAH as the main component. The result is shown in FIG.

As shown in FIG. 3, in Experimental Example 1 in which the NP medium was brought into contact with the activated carbon 71 to remove substances adsorbed on the activated carbon 71, about 10% of the PAH was removed from the tar-impregnated soil. Had been removed. Then, by the subsequent slurry treatment, about 63% of the PAH was degraded by the tar-degrading microorganism.

On the other hand, in Comparative Example 1, as shown in FIG.
Even after the slurry treatment for 12 weeks, the PAH concentration in the tar-impregnated soil hardly changed.

In general, in the slurry treatment, the medium is agitated, so that oxygen is actively supplied. In addition, since there are many opportunities for the microorganisms to come in contact with the organic matter to be decomposed, the decomposition of the organic matter by the microorganisms proceeds rapidly. It is known to Even when the slurry treatment was performed, in Comparative Example 1, the PAH did not decompose, so that the factor inhibiting the decomposition of the tar was not oxygen shortage or insufficient contact between the tar component and the tar decomposing microorganism. Guessed. And, since the difference between the experimental conditions of the experimental example 1 and the comparative example 1 is the presence or absence of the washing operation, the substance adsorbed on the activated carbon 71 suppresses the tar decomposition by the tar decomposing microorganism. it is conceivable that.

Here, the activated carbon 7 used in Example 1 was used.
As shown in FIG. 4, the PAH adsorbed on No. 1 was mainly
Naphthalene, a 2- to 4-cyclic PAH, especially a bicyclic PAH, accounted for about 70%. These PAHs
Among the poorly soluble PAHs, they have relatively high solubility in water. Therefore, it is considered that these PAHs were eluted from the tar-impregnated soil into the NP medium and captured by the activated carbon 71 in the process of circulating in the water circulation path. Therefore, in Experimental Example 1, PAHs having relatively high water solubility such as naphthalene were removed from the soil 1 to be purified, thereby suppressing an increase in the concentration of PAH in the NP medium. It is considered that PAH decomposition was promoted.

[Experimental Example 2] In Experimental Example 2, the liquid supply pump P3 was driven to supply the NP medium into the housing section 61 from the lower part to the upper part at a flow rate of 2 mL / min. Then, the air pump P4 was driven to supply air from the lower part to the upper part of the housing part 61 at a flow rate of 300 mL / min from the air supply pipe 9 to the NP medium. The NP culture medium discharged from the upper part of the storage part 61 is conveyed to the adsorption column 7 through the liquid feed pipe 82 and comes into contact with the activated carbon 71 provided therein, and again from the adsorption column 7 to the liquid feed pipe. 81 to the accommodation section 61
And supplied to the tar impregnated soil.

Here, the liquid sending pump P3 is connected to the N
At the same time that the P medium is sucked from the tar-impregnated soil, the function is to supply the oxygen-enriched NP medium to the tar-impregnated soil. By smoothly sucking and supplying the NP medium from the tar-impregnated soil, the NP medium moves throughout the tar-impregnated soil as a carrier for oxygen and nutrients.

As a result of continuing this operation for two weeks, the PAH of the 2- to 4-cyclic in the tar-impregnated soil was reduced by about 15%.

Comparative Example 2 In Comparative Example 2, the conditions were the same as in Experimental Example 2 except that the adsorption column 7 was not provided.
After 2 weeks of treatment, the rate of reduction of the 2- to 4-membered cyclic PAH is about 5
%Met.

Also between Experimental Example 2 and Comparative Example 2,
It can be seen that the decomposition rate of PAH differs greatly depending on the presence or absence of activated carbon as an adsorbent, and that the activated carbon removes naphthalene and the like, thereby promoting tar decomposition by the tar-decomposing microorganism.

[Another Embodiment] Another embodiment will be described below. (B) In the above embodiment, the case where the organic substance to be removed is tar is illustrated, but the soil purification method according to the present invention is not particularly limited as long as the target to be removed is an organic substance. In this method, other inhibitors that can be adsorbed by activated carbon and inhibitors that can be adsorbed by adsorbents other than activated carbon (eg, zeolites, molecular sieves, silica gels, etc.) can reduce the activity of microorganisms that decompose organic substances to be removed. It is effective when used when it is inhibiting. (B) In the above embodiment, a microorganism that decomposes organic matter to be removed is added to the soil to be purified from the outside to reinforce the function of indigenous microorganisms that naturally inhabit the soil to be purified. The present method can also be used to improve the efficiency of decomposing the organic matter by activating indigenous microorganisms living in the soil to be purified. (C) In the above embodiment, the ventilation section 4 is formed in the saturated soil 12. However, an aeration tank may be provided downstream of the collection section 2, or the collection pipe 21 and the supply pipe 31 may be provided.
By supplying air using an air pump, the recovered liquid supplied to the purification target soil 1 can be enriched with oxygen and used as oxygen supply water. (D) In the above embodiment, the NP medium, which is a nutrient source of the microorganism, was circulated. However, the circulating fluid was determined in consideration of the nutritional requirement of the microorganism, which is useful for decomposing the organic matter to be purified. Can be changed as appropriate. Alternatively, the liquid collected from the soil gap of the soil to be purified may be reused as it is, or the liquid may be replenished with nutrients and re-supplied.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an embodiment of the present method.

FIG. 2 is a schematic diagram of a soil purification model system used in an example of the present method.

FIG. 3 is a graph showing the results of tar decomposition by the present method.

FIG. 4 is a graph showing the result of removing tar components by the present method.

FIG. 5 is a graph showing the results of tar decomposition by a conventional method.

[Explanation of symbols]

 Reference Signs List 1 soil to be purified 2 collection unit 3 supply unit 4 ventilation unit 5 adsorption tower 11 unsaturated soil 12 saturated soil 52 adsorbent

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C09K 17/32 B09B 3/00 ZABE C09K 101: 00 5/00 SF term (reference) 2D043 DA04 EB06 4D004 AA41 AB10 AC04 AC07 CA18 CA47 CC02 4D024 AA05 AB04 BA02 BC01 DB14 4H026 AA01 AA10 AB04

Claims (5)

[Claims] 1. A soil purification method for removing organic substances contained in a soil to be purified using microorganisms, wherein: a suction step of sucking soil pore water in the soil to be purified; and the soil gap sucked in the suction step. An adsorption step of bringing water into contact with an adsorbent that adsorbs an inhibitor that inhibits the removal of the organic substance by the microorganism; and supplying the soil pore water that has been brought into contact with the adsorbent in the adsorption step to the soil to be purified. A soil purification method comprising: 2. The soil purification method according to claim 1, further comprising an oxygen addition step of adding oxygen to the soil pore water. 3. The soil purification method according to claim 1, wherein the inhibitor is naphthalene or a derivative thereof. 4. The method according to claim 1, wherein said adsorbent is activated carbon.
The soil purification method according to any one of the above. 5. The soil purification method according to claim 1, wherein the soil to be purified is treated in situ.