JP2016193415A - Clarifier for contaminated ground, manufacturing method of clarifier for contaminated ground and clarification method of contaminated ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clarify a contaminated material contained in contaminated ground longer term.SOLUTION: The invention is a clarifier for contaminated ground for activating microorganisms degrading an organic chlorine compound in ground by injecting the ground contaminated by the organic chlorine compound and contains glycerin, plant oil, starch and a surfactant. The starch is contained in a range of 5 wt.% to 20 wt.%, the surfactant is contained in a range of 1.25 wt.% to 10 wt.% and the balance is preferably glycerin and the plant oil.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a contaminated ground purification agent, a method for producing a contaminated ground purification agent, and a method for purifying a contaminated ground.

  In order to purify ground contaminated with volatile organochlorine compounds (VOC) such as trichlorethylene (TCE), there is known a method for purifying contaminated ground that activates microorganisms that are resident in the ground. In this purification method, in order to activate microorganisms, a purification agent containing nutrient components of microorganisms is injected into the ground. Some of these purifying agents contain glycerin as an immediate-acting nutritional component and starch as a sustained-release nutritional component (see, for example, Patent Document 1).

JP 2012-125706 A

  In the above-mentioned cleaning agent, since glycerin enters between starch molecules, glycerin can be reliably supplied to the viscous soil layer. Moreover, since the starch which is a sustained-release nutrient component is contained, a nutrient component can be supplied with respect to microorganisms over a long period of time.

  Here, if a nutrient component having a higher sustained release property than starch can be used, the activation period of the microorganisms by the purifying agent can be extended as compared with the conventional case, and the contaminant can be purified over a longer period.

  The present invention has been made in view of such circumstances, and an object thereof is to purify contaminants for a longer period.

  In order to achieve the above-mentioned object, the present invention provides a cleansing agent for contaminated ground which is injected into a ground contaminated with an organic chlorine compound and activates microorganisms in the ground that decomposes the organic chlorine compound, which is glycerin. And vegetable oil, starch, and a surfactant.

  The present invention also provides a method for purifying contaminated ground, wherein the soil contaminated with an organic chlorine compound is purified by activating microorganisms in the ground for decomposing the organic chlorine compound. An injection hole forming step for forming an injection hole in the ground, and a purification agent injection step for injecting a purification agent containing glycerin, vegetable oil, starch, and a surfactant into the injection hole. To do.

  According to these inventions, since vegetable oil is contained as a sustained-release nutritional component, contaminants can be purified over a longer period. Moreover, since glycerin which is an immediate effect nutrient component is contained, the nutrient component can be released from the initial stage of injection. Furthermore, since starch and surfactant are contained, vegetable oil can be disperse | distributed in a stable state with respect to glycerol.

  Further, the present invention is a method for producing a contaminated soil purifier that is injected into a soil contaminated with an organic chlorine compound and activates microorganisms in the ground that decompose the organic chlorine compound, and starch is added to glycerin. A first mixing step of adding and mixing, a second mixing step of adding and mixing a surfactant to the first mixture obtained in the first mixing step, and a second obtained in the second mixing step. And a third mixing step of adding vegetable oil to the mixture and mixing.

  According to the present invention, in the first mixing step, starch is dispersed in glycerin, and in the second mixing step, the surfactant is adsorbed and dispersed in the dispersed starch. For this reason, vegetable oil is taken in into surfactant by performing a 3rd mixing process, and vegetable oil can be disperse | distributed in a stable state with respect to glycerol.

  In the above invention, the starch is contained in the range of 5 wt% to 20 wt%, the surfactant is contained in the range of 1.25 wt% to 10 wt%, and the remainder is the glycerin and the vegetable oil. It is preferable that

  According to the present invention, the pollutant contained in the contaminated ground can be purified over a longer period.

It is a figure explaining the material used by the sustainability confirmation test. (A) is a figure explaining the preparation procedure of the sample which uses emulsified vegetable oil, (b) is a figure explaining the preparation procedure of the sample which uses the dextrin used as a comparative example. It is a figure explaining the time-dependent change of the trichlorethylene density | concentration in a control section. It is a figure explaining the time-dependent change of the trichlorethylene density | concentration in the sample which uses emulsified vegetable oil. It is a figure explaining the time-dependent change of the trichlorethylene density | concentration in the sample which uses dextrin. It is a figure explaining the material used by the mixing evaluation test. It is a figure explaining the result of a mixing evaluation test. It is a figure explaining the result of a starch addition amount evaluation test. It is a figure explaining surfactant used by surfactant evaluation test. It is a figure explaining the result of a surfactant evaluation test. It is a figure explaining the purification process of a contaminated ground, (a) is a figure explaining the injection well formed in the ground, (b) is a figure explaining the state which inject | poured the cleaning agent into the injection well, (c) is The figure explaining typically a mode that glycerin diffuses, and (d) is a figure explaining typically a mode that vegetable oil diffuses. It is a figure which illustrates the manufacturing process of a purification agent, (a) is explanatory drawing of a 1st mixing process, (b) is explanatory drawing of a 2nd mixing process, (c) is explanatory drawing of a 3rd mixing process. (D) is a figure explaining the manufactured purification agent.

  Embodiments of the present invention will be described below. In this embodiment, a sustainability confirmation test, a mixing evaluation test, a starch addition amount evaluation test, and a surfactant evaluation test were performed. Hereinafter, these tests will be described.

  In the sustainability confirmation test, emulsified vegetable oil is selected as the nutrient component of the organochlorine compound (VOC) degrading microorganism, and which nutrient component is a decomposing microorganism over a long period of time compared to starch, which is a nutrient component of conventional nutrients. It was confirmed whether or not can be activated.

  FIG. 1 is a diagram illustrating materials used in the sustainability confirmation test. As shown in the figure, mountain sand was used as soil in this sustainability confirmation test. This mountain sand is inhabited by decomposing microorganisms that decompose VOCs. Commercial products were used as emulsified vegetable oils as nutrients. Specifically, an anaerobic microbial activator “EOS emulsified oil substrate” manufactured by EOS Remediation, LLC was used. Dextrin was used as starch as a nutritional component. This dextrin is a low molecular weight carbohydrate in which several α-glucoses are polymerized by glycosidic bonds. Further, as simulated contaminated water, a TCE solution in which trichlorethylene was dissolved in deionized water to a concentration of 5 mg / L was used.

  FIG. 2 is a diagram for explaining a procedure for producing a sample to be analyzed. As shown in FIG. 2A, in the sample using emulsified vegetable oil, 100 g of soil 11 and 10 g of emulsified vegetable oil 12A were added to the medium bottle 10A, and 300 mL of the TCE solution 13 was further added to the medium bottle 10A. By mixing and stirring these, the emulsified vegetable oil 12A was dispersed in the TCE solution 13, and a first-stage sample containing the TCE solution 14A containing nutrients and the soil 11 was produced.

  A first specified amount (described later) of the supernatant (nutrient-containing TCE solution 14A) was collected from the first stage sample and transferred to another medium bottle 10B. A second stage sample was prepared by previously adding 100 g of soil and a second specified amount (described later) of deionized water to another medium bottle 10B and mixing them. In the second stage sample, the diluted TCE solution 14A was 300 mL. In addition, the TCE solution 13 was replenished to the first stage sample, and the liquid volume was returned to 300 mL.

  Similarly, for the second stage sample, the first defined amount of the supernatant (diluted TCE solution 14A) was collected and transferred to another medium bottle 10C. A third stage sample was prepared by previously adding 100 g of soil and a second specified amount of deionized water to the medium bottle 10C and mixing them. The diluted TCE solution 14A in the third stage sample was 300 mL.

  Thereafter, the first stage sample was cured at room temperature (20 to 22 ° C.), and the second stage sample and the third stage sample were prepared by the above-described procedure every time a predetermined period passed. With regard to this predetermined period (curing period), the period of 3 years from the start of the test was 1 to 2 months, and thereafter 3 months. Moreover, regarding the first specified amount in each sample, it was 50 mL for 3 years from the start of the test, and 100 mL thereafter. Along with this, the second specified amount was 250 mL until the start of the test for 3 years, and thereafter 200 mL.

  As shown in FIG. 2 (b), the sample using dextrin was also prepared in the same procedure as the sample using emulsified vegetable oil. That is, by adding 100 g of soil 11 and 10 g of dextrin 12B to the medium bottle 10D, and further adding 300 mL of the TCE solution 13 to the medium bottle 10D, the first stage including the TCE solution 14B containing nutrients and the soil 11 is added. A sample of was prepared.

  Collect the first specified amount of supernatant (TCE solution 14B containing nutrients) from the sample in the first stage, transfer to another medium bottle 10E to which 100 g of soil and a second specified amount of deionized water have been added in advance, and mix. Thus, a second stage sample was produced.

  Similarly, a first defined amount of supernatant (diluted TCE solution 14B containing nutrient components) is collected from the second stage sample, and another medium in which 100 g of soil and a second defined amount of deionized water are added in advance. The sample in the third stage was prepared by transferring to the bottle 10F and mixing.

  In addition, regarding each sample using the dextrin 12B, the curing period, the first specified amount, and the second specified amount are the same as the sample using the emulsified vegetable oil 12A.

  The test results are shown in FIGS. FIG. 3 is a diagram for explaining the change with time of the trichlorethylene concentration in the target section. FIG. 4 is a diagram for explaining the change with time of the trichlorethylene concentration in the sample using the emulsified vegetable oil. FIG. 5 is a diagram for explaining the change over time in the trichlorethylene concentration in a sample using dextrin.

  Here, the target section is a sample to which 10 g of deionized water is added without adding any nutritional components, and samples of the first stage to the third stage are prepared in the same manner as the sample using emulsified vegetable oil or dextrin. . And the sample of the 2nd step and the 3rd step was produced at the time shown with the triangular symbol in these figures, and the trichlorethylene concentration was measured about the sample of the 3rd step.

  As shown in FIG. 3, in the target area, the TCE concentration decreased to about 1 mg / L due to the purification ability of the degrading microorganisms in the period from the start of the test to about 360 days. However, after 360 days, the ability of degrading microorganisms to purify was not exhibited, and the TCE concentration remained around 30 mg / L.

  As shown in FIG. 4, in the sample using the emulsified vegetable oil, a decrease in TCE was confirmed in the period from the start of the test to about 100 days. In about 100 days from the start of the test, the TCE concentration decreased to 0.01 mg / L. This is thought to be due to the improvement of the purification capacity accompanying the growth of the decomposing microorganisms. Thereafter, the TCE concentration up to 300 days was maintained at 0.01 mg / L. This is presumably because the TCE contained in the third stage sample was rapidly degraded by the sufficiently grown degrading microorganisms. After 350 days, the TCE concentration was increased to about 10 mg / L by the addition of TCE, but the TCE concentration decreased to 0.01 mg / L after a predetermined curing period (1 to 3 months). From this, it can be seen that the decomposing microorganisms that inhabit the soil 11 are active using the emulsified vegetable oil (nutrient component) added at the beginning of the test as a nutrient source. For this reason, in the sample using emulsified vegetable oil, it can be said that TCE was decomposed by decomposing microorganisms until about 1300 days passed from the start of the test.

  As shown in FIG. 5, in the sample using dextrin, a tendency to decrease TCE was confirmed immediately after the start of the test, and the TCE concentration decreased to 0.01 mg / L about 30 days after the start of the test. This is also considered to be due to the improvement of the purification capacity accompanying the growth of the decomposing microorganisms. Thereafter, the TCE concentration up to 360 days was maintained at 0.01 mg / L. This is also considered to be because TCE contained in the third-stage sample was rapidly degraded by the sufficiently grown degrading microorganisms. After 360 days, the TCE concentration was increased to about 10 mg / L by the addition of TCE, but the TCE concentration decreased to 0.01 mg / L after a predetermined curing period (1 to 2 months). Even in the sample using dextrin, it can be seen that the decomposing microorganisms that inhabit the soil 11 are active using the emulsified vegetable oil (nutrient component) added at the beginning of the test as a nutrient source. In this sample, the TCE concentration could be reduced to 0.01 mg / L in the period from the start of the test to about 550 days. However, the purification ability of degrading microorganisms decreased from 600 days to 700 days, and the TCE concentration from 700 days onward remained around 15-20 mg / L. For this reason, in the sample using dextrin, it can be said that TCE was decomposed by decomposing microorganisms until about 550 days passed from the start of the test.

  From the above sustainability confirmation test, it was confirmed that by using emulsified vegetable oil as a nutrient component of the degradation microorganism, it was possible to activate the degradation microorganism over a longer period than using starch, which is a nutrition component of the comparative example.

  By the way, the emulsified vegetable oil used in the sustainability confirmation test is a commercial product, and a special device such as a homogenizer (high pressure, high speed stirrer) is required for production. However, it is difficult to bring a homogenizer into the contaminated ground purification site. In addition, commercially available emulsified vegetable oil contains moisture, and when used as a purifying agent, the ratio of nutrient components decreases by the amount of water.

  Therefore, mixing evaluation to determine a mixing method that can sufficiently emulsify vegetable oil and reduce the amount of surfactant added even with a concrete hand mixer (rated output 700 W to 1 kW, rotation speed 400 to 1000 rpm). A test was conducted. Hereinafter, the mixing evaluation test will be described.

  FIG. 6 is a diagram for explaining materials used in the mixing evaluation test. As shown in the figure, in this mixed evaluation test, commercially available edible vegetable oil was used as the vegetable oil. This edible vegetable oil is a mixed salad oil in which a plurality of types of oils (vegetable oils) derived from plants are mixed. In addition, glycerin was used as a nutritional component having an immediate effect, and starch (corn starch) and a surfactant (polyglycerin fatty acid ester) were used as materials for emulsifying glycerin and vegetable oil.

  In the mixing evaluation test, the order of mixing the above four types of materials was examined. As shown in FIG. 7, the material to be the base was material A, and the material mixed with material A in the first mixing stage was material B. Then, with respect to the mixture of the material A and the material B obtained in the first mixing stage (first mixture), the material mixed in the second mixing stage is defined as the material C, and the material A obtained in the second mixing stage. The material mixed in the third mixing stage with respect to the mixture of material B, material B and material C (second mixture) was designated as material D. In addition, mixing was performed by stirring with a chemical spoon. The mixing time was 10 minutes. Hereinafter, each sample will be described with reference to FIG.

  Sample No. In 1, material A was vegetable oil and 81 g was added. Material B was a surfactant and 4 g was added. Material C was corn starch and 15 g was added. Material D was glycerin and 100 g was added. In addition, since the addition amount of each material is the same also with another sample, subsequent description is abbreviate | omitted. In the first mixing stage, a surfactant was added to the vegetable oil and mixed. In the second mixing stage, corn starch was added to and mixed with the first mixture of vegetable oil and surfactant. In the third mixing stage, glycerin was added to and mixed with the second mixture of vegetable oil, surfactant and corn starch.

  Sample No. In 2, the material A is vegetable oil, the material B is a surfactant, the material C is glycerin, and the material D is corn starch. In the first mixing stage, a surfactant was added to the vegetable oil and mixed. In the second mixing stage, glycerin was added to and mixed with the first mixture of vegetable oil and surfactant. In the third mixing stage, corn starch was added to and mixed with the second mixture of vegetable oil, surfactant and glycerin.

  Sample No. 3, material A is vegetable oil, material B is corn starch, material C is a surfactant, and material D is glycerin. In the first mixing stage, corn starch was added to the vegetable oil and mixed. In the second mixing stage, a surfactant was added to the first mixture of vegetable oil and corn starch and mixed. In the third mixing stage, glycerin was added to and mixed with the second mixture of vegetable oil, corn starch and surfactant.

  Sample No. 4, the material A is glycerin, the material B is a surfactant, the material C is vegetable oil, and the material D is corn starch. In the first mixing stage, a surfactant was added to glycerin and mixed. In the second mixing stage, vegetable oil was added to and mixed with the first mixture of glycerin and surfactant. In the third mixing stage, corn starch was added to and mixed with the second mixture of glycerin, surfactant and vegetable oil.

  Sample No. 5, the material A is glycerin, the material B is a surfactant, the material C is corn starch, and the material D is vegetable oil. In the first mixing stage, a surfactant was added to glycerin and mixed. In the second mixing stage, corn starch was added to and mixed with the first mixture of glycerin and surfactant. In the third mixing stage, vegetable oil was added to and mixed with the second mixture of glycerin, surfactant and corn starch.

  Sample No. 6, material A is glycerin, material B is corn starch, material C is a surfactant, and material D is vegetable oil. In the first mixing stage, corn starch was added to glycerin and mixed. In the second mixing stage, a surfactant was added to the first mixture of glycerin and corn starch and mixed. In the third mixing stage, vegetable oil was added to and mixed with the second mixture of glycerin, corn starch and surfactant.

  In this evaluation test, Sample No. 1-No. 6 was observed on the next day of mixing, and it was evaluated by visual observation whether vegetable oil and glycerin were mixed (emulsified) or separated. The evaluation results are shown in the next day separation status column in FIG.

  As shown in this column, sample no. 1-No. Regarding 5, the vegetable oil and glycerin were separated. For example, sample no. 1-No. Regarding 2, the surfactant was difficult to dissolve directly in the vegetable oil. Sample No. Regarding No. 3, when corn starch was directly added to the vegetable oil, agglomeration occurred and it was difficult to uniformly disperse. In contrast, sample no. In 6, the vegetable oil and glycerin were mixed (emulsified).

  Here, sample No. The reason why vegetable oil and glycerin are mixed with respect to 6 will be considered. Although starch such as corn starch is a polysaccharide and does not dissolve in water, it has many hydroxyl groups, so it can be easily and uniformly dispersed in highly hydrophilic glycerin. It is also clear that this starch has hydrophobicity by not dissolving in water. For this reason, it is considered that a surfactant that is difficult to dissolve in glycerin having strong hydrophilicity but also has hydrophobicity is adsorbed to starch. That is, the surfactant is considered to be dispersed in glycerin by adsorbing to starch that is uniformly dispersed in glycerin. The vegetable oil is considered to be uniformly dispersed and mixed (emulsified) in glycerin by adsorbing to the surfactant.

  In addition, it is known that the polymer compound has an action of dispersing the colloid when the concentration is higher than a predetermined concentration. It is considered that glycerin and vegetable oil could be emulsified by a synergistic effect of the dispersion action of starch and surfactant and the colloidal dispersion action of the polymer compound even with a weak force of stirring by a medicine spoon. In addition, since it could emulsify by stirring with a chemical spoon, it can be said that it can fully emulsify in the field by using a hand mixer for concrete.

  As described in the sustainability confirmation test, starch (corn starch) and vegetable oil are both nutrient components of decomposing microorganisms, but vegetable oil activates decomposing microorganisms for a longer period of time than starch. For this reason, in the cleaning agent, it is desirable to reduce the starch content as much as possible and to increase the vegetable oil content by that amount. Then, the test (starch addition amount evaluation test) which evaluates starch addition amount was done.

  In the starch addition amount evaluation test, the four types of materials described in FIG. 6 were used. And as shown in FIG. 8, the addition state of the corn starch and the vegetable oil was changed, and the mixed state (emulsified state) was evaluated. The mixing procedure is the same as the sample No. in the mixing evaluation test. 6 (FIG. 7), the description is omitted. In addition, each sample No. in FIG. 1-No. 6, the amount used of glycerin of material A was fixed at 100 g (50% by weight of the whole), and the amount of use of surfactant of material C was fixed at 4 g (2% by weight of the whole). Description of is omitted.

  Sample No. 1, the corn starch of material B was 0 g, and the vegetable oil of material D was 96 g. Sample No. 2 corn starch 5g, vegetable oil 91g, sample No. In No. 3, 10 g of corn starch and 86 g of vegetable oil were used. Similarly, sample no. In No. 4, 15 g of corn starch and 81 g of vegetable oil were used. In No. 5, 20 g of corn starch and 76 g of vegetable oil were used. In No. 6, 40 g of corn starch and 56 g of vegetable oil were used.

  As shown in FIG. 1 and no. In sample 2, glycerin and vegetable oil were separated within 2 hours from the end of stirring. No. In sample 3, glycerin and vegetable oil separated 3 to 4 hours after the end of stirring. Generally, in the purification method for contaminated ground, a purification agent is produced on site, and the produced purification agent is immediately injected into an injection well. For this reason, if it is mixed for 3 to 4 hours after completion | finish of stirring, it will be thought that there will be no special trouble in field work. No. 4-No. In the sample of 6, the mixed state (emulsified state) of glycerin and vegetable oil was maintained even after 24 hours had elapsed from the end of stirring.

  From the above results, when the amount of surfactant used is 4 g (2 wt%), corn starch is added in the range of 10 g (5 wt%) to 40 g (20 wt%) in order to emulsify the vegetable oil. It can be said that it is preferable. And if the mixed state of glycerin and vegetable oil is maintained over 24 hours or more, it can be said that it is preferable to add corn starch in the range of 15 g (7.5 wt%) to 40 g (20 wt%).

  In the above evaluation test, the amount of surfactant used is fixed at 4 g (2% by weight). However, the amount of surfactant used should be considered in terms of the effects of degradation microorganisms in the ground and the environment. Determined. Generally, if it is 10% by weight or less, it can be used without affecting the decomposed microorganisms in the ground and the environment. And if the usage-amount of surfactant increases, the quantity of the corn starch required for it can be decreased.

  Moreover, in the produced cleaning agent, since materials other than starch (corn starch) and vegetable oil are glycerin and vegetable oil, it does not contain water, and it can be said that the content rate of the nutrient component in a cleaning agent can be raised. . Also in this respect, it is possible to continue supplying nutrient components to the decomposing microorganisms over a long period of time.

  In each of the tests described above, among the polyglycerin fatty acid esters as surfactants, those containing monolauric acid hexaglycerin as the main component were used, but other types of surfactants belonging to polyglycerin fatty acid esters were also evaluated. It was. Hereinafter, a test for evaluating the surfactant (surfactant evaluation test) will be described.

  FIG. 9 is a diagram for explaining the surfactant used in the surfactant evaluation test. As shown in the figure, in this surfactant evaluation test, the surfactant SF1 having an HLB value of 15.5 containing lauric acid polyglycerin-10 as the main component and hexaglyceryl monolaurate as the main components. The surfactant SF2 having an HLB value of 14.5 and the surfactant SF3 containing decaglyceryl stearate as a main component and having an HLB value of 12 were used.

  In addition, the surfactant SF1 used the brand name: Decaglyn 1-LVEX of Nikko Chemicals Corporation. As the surfactant SF2, trade name: Hexaglyn 1-L of Nikko Chemicals Co., Ltd. was used. As the surfactant SF3, trade name: Poem J-0081HV of Riken Vitamin Co., Ltd. was used.

  In the surfactant evaluation test, the addition amount of the above three kinds of surfactants SF1 to SF3 was adjusted, and the addition amount of corn starch and vegetable oil was also adjusted, so that sample No. 1-No. 6 was produced. Hereinafter, each sample will be described with reference to FIG. In each sample, the mixing procedure is the same as in each of the above-described tests, and thus the description thereof is omitted.

  Sample No. In No. 1, glycerin is 100 g (50 wt%), corn starch is 15 g (7.5 wt%), surfactant SF1 is 5 g (2.5 wt%), vegetable oil is 80 g (40 wt%). 2, 100 g (49 wt%) of glycerin, 20 g (9.8 wt%) of corn starch, 2.5 g (1.2 wt%) of surfactant SF1, and 82.5 g (40 wt%) of vegetable oil did.

  Sample No. 3, 100 g (44.4 wt%) of glycerin, 40 g (17.8 wt%) of corn starch, 5 g (2.2 wt%) of surfactant SF2, and 80 g (35.6 wt%) of vegetable oil Sample No. In No. 4, glycerin is 100 g (49 wt%), corn starch is 20 g (9.8 wt%), surfactant SF2 is 2.5 g (1.2 wt%), and vegetable oil is 82.5 g (40 wt%). did.

  Sample No. 5, 100 g (44.4 wt%) of glycerin, 40 g (17.8 wt%) of corn starch, 5 g (2.2 wt%) of surfactant SF3, and 80 g (35.6 wt%) of vegetable oil Sample No. In No. 6, glycerin was 100 g (44.4 wt%), corn starch was 40 g (17.8 wt%), surfactant SF3 was 4 g (1.8 wt%), and vegetable oil was 81 g (36 wt%).

  In any sample, the mixed state (emulsified state) of glycerin and vegetable oil was maintained even after 24 hours had elapsed from the end of stirring. From this viewpoint, it can be said that any of the surfactants SF1 to SF3 can be used satisfactorily. And vegetable oil can be disperse | distributed if it contains by the density | concentration of 1.25 weight% or more regarding the density | concentration of surfactant SF1-SF3. In addition, it is preferable that the density | concentration of surfactant SF1-SF3 is 10 weight% or less from a viewpoint that it does not affect the decomposition | disassembly microorganisms in a ground and an environment.

  Focusing on the viscosity, sample No. using surfactant SF3. No. 5 has a viscosity of 13.7 Pascal seconds, sample no. The viscosity of 6 was 12 Pascal seconds. On the other hand, sample No. using surfactant SF1. No. 1 has a viscosity of 9.5 Pascal seconds, Sample No. The viscosity of 2 was 8.9 Pascal seconds. Sample No. using surfactant SF2 No. 3 has a viscosity of 9.6 Pascal seconds, sample no. The viscosity of 4 was 8 Pascal seconds. From the viewpoint of viscosity, it can be said that the surfactants SF1 and SF2 are better than the surfactant SF3.

  Focusing on the addition ratio of corn starch, sample No. using surfactant SF3. 5 and no. 6 was 17.8% by weight, and sample No. 6 using the surfactant SF2 was added. The addition ratio of 3 was also 17.8% by weight. And sample No. using surfactant SF2. The addition ratio of 4 was 9.8% by weight. In addition, sample No. using surfactant SF1. 2 was 9.8% by weight. The addition ratio of 1 was 7.5% by weight.

  As described above, corn starch and vegetable oil are both nutrients of decomposing microorganisms, but vegetable oil continues to release nutrients over a long period of time. For this reason, if the addition ratio of corn starch becomes low, the use ratio of vegetable oil can be raised to that extent. From this viewpoint, it can be said that the surfactant SF2 is preferable to the surfactant SF3, and the surfactant SF1 is preferable to the surfactant SF2.

  Next, a method for purifying contaminated ground according to the present embodiment using the above-described purifying agent will be described. In this purification method, as shown in FIG. 11 (a), the injection well 21 reaching the viscous soil layer G1 existing below the ground surface is provided for the contaminated ground G. The injection well 21 is provided as a thin and long hole having a diameter of about 5 cm and a depth of about 10 m, for example. The injection well 21 may be a boring hole provided so as to reach the viscous soil layer G1 from the ground surface.

  If the injection well 21 is provided in the contaminated ground G, the purifier 22 is manufactured. For example, the sample No. described in FIG. 3-No. 6 and the sample No. described in FIG. 1-No. 6 is produced. In producing the cleaning agent 22, for example, as shown in FIGS. 12 (a) to (d), corn starch (starch) 22b is added to glycerin 22a charged into the mixing container MC, and a hand mixer HM for concrete is used. Obtained in the first mixing step, the second mixing step in which the surfactant 22c is added to the first mixture MIX1 obtained in the first mixing step and mixed by the hand mixer HM, and the second mixing step. A vegetable oil 22d is added to the second mixture MIX2 and mixed with the hand mixer HM. By performing the first to third mixing steps, a purification agent 22 in which vegetable oil is mixed (emulsified) with glycerin is produced in the mixing container MC.

  As described in the mixing evaluation test, in the first mixing step, corn starch 22b is mixed with glycerin 22a, in the second mixing step, the surfactant 22c is mixed in the first mixture MIX1, and in the third mixing step, the second is mixed. Since the vegetable oil 22d is mixed with the mixture MIX2, the vegetable oil can be mixed with glycerin even in the concrete hand mixer HM having a rated output of 700 W to 1 kW and a rotational speed of 400 to 1000 rpm.

  The purifier 22 produced by the above procedure is injected into the injection well 21 as shown in FIG. As shown in FIG. 11 (c), when the purifying agent 22 is injected, first, glycerin 22a, which is a low molecular compound and has relatively low adsorptivity to soil, quickly diffuses in the viscous soil layer G1. . By supplying the glycerin 22a in this way, the decomposing microorganisms that are always present in the viscous soil layer G1 are quickly activated. Therefore, decomposition of the organochlorine compound (VOC) contained in the viscous soil layer G1 is started early.

  When glycerin is released, sustained-release nutritional components are released. In the purifying agent 22 of the present embodiment, the vegetable oil 22d is a main component as a sustained-release nutritional component. Therefore, as shown in FIG. 11 (d), even after the starch is released, the decomposed microorganisms are removed by the vegetable oil 22d. Can continue to be activated. As a result, the decomposing microorganisms of the viscous soil layer G1 can be activated continuously over a long period of time, and the viscous soil layer G1 can be purified over a long period of time.

  The above description of the embodiment is for facilitating the understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof. For example, you may comprise as follows.

  Regarding the vegetable oil, in the above-described embodiment, a commercially available edible vegetable oil (formulated salad oil) is used. However, the present invention is not limited to this. For example, soybean oil, rapeseed oil, olive oil, and a mixed oil thereof can be used. In short, a plurality of types of fats and oils derived from plants can be used. And regarding the content rate of the vegetable oil in a purification agent, vegetable oil should just be mixed (emulsified) with glycerin, but when the sustained release property of vegetable oil is considered, it is preferable that there are more than starch. Moreover, if the content ratio of the vegetable oil exceeds 50% by weight of the cleaning agent, there is a concern that the vegetable oil is not emulsified. Considering these, it is preferable that the content of the vegetable oil in the cleaning agent is 25% by weight or more and 50% by weight or less.

  Regarding starch, corn starch was used in the above-described embodiment, but the present invention is not limited thereto. For example, various starches such as tapioca starch, potato starch, and wheat flour can be used.

  Regarding the surfactant, the polyglycerol fatty acid ester is used in the above-described embodiment, but the present invention is not limited to this. For example, sorbitan fatty acid ester and propylene glycol fatty acid ester can be used.

10A to 10F ... medium bottle, 11 ... soil, 12A ... emulsified vegetable oil, 12B ... dextrin, 13 ... TCE solution, 14A-14B ... TCE solution with nutrients, 21 ... injection well, 22 ... purifier, 22a ... glycerin, 22b ... corn starch, 22c ... surfactant, 22d ... vegetable oil, G ... contaminated ground, G1 ... viscous soil layer, HM ... hand mixer, MIX1 ... first mixture, MIX2 ... second mixture

Claims (5)

A contaminated soil purifying agent that is injected into the soil contaminated with an organic chlorine compound and activates microorganisms in the ground to decompose the organic chlorine compound,
Glycerin,
Vegetable oil,
Starch,
A cleansing agent for contaminated ground, comprising a surfactant. The starch is contained in a range of 5 wt% to 20 wt%,
The surfactant is contained in the range of 1.25 wt% to 10 wt%,
The remainder is the glycerin and the vegetable oil,
The cleaning agent for contaminated ground according to claim 1. A method for producing a contaminated soil purification agent that is injected into a soil contaminated with an organic chlorine compound and activates microorganisms in the ground that decompose the organic chlorine compound,
A first mixing step of adding starch to glycerin and mixing;
A second mixing step of adding and mixing a surfactant to the first mixture obtained in the first mixing step;
A third mixing step of adding and mixing vegetable oil to the second mixture obtained in the second mixing step;
The manufacturing method of the purification agent for contaminated ground characterized by performing. In the first mixing step, the starch in an amount of 5 wt% to 20 wt% is added to the glycerin and mixed,
In the said 2nd mixing process, the said surfactant of 1.25 weight% or more and 10 weight% or less is added and mixed with the said 1st mixture, The cleaning agent for contaminated ground of Claim 3 characterized by the above-mentioned. Production method. A method for purifying contaminated ground, wherein the soil contaminated with an organic chlorine compound is purified by activating microorganisms in the ground for decomposing the organic chlorine compound,
An injection hole forming step for forming an injection hole in the soil contaminated with an organic chlorine compound;
A cleaning agent injection step of injecting a cleaning agent containing glycerin, vegetable oil, starch, and a surfactant into the injection hole;
A method for purifying contaminated ground, characterized in that

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