JP4128014B2 - Contaminant concentration measurement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for measuring the concentration of a pollutant used when a pollutant contained in polluted soil or contaminated groundwater is decomposed with the decomposition activity of microorganisms and the state of the decomposition treatment is inspected.
[0002]
[Prior art]
The soil such as the site of the factory may contain volatile organic compounds, for example, volatile organic compounds such as trichlorethylene. If such soil is left as it is, pollutants such as volatile organic compounds will become groundwater. There is a risk that it may diffuse into the environment due to leaching into the atmosphere or volatilization into the atmosphere, and therefore, such contaminated soil and contaminated groundwater must be subjected to a predetermined purification treatment.
[0003]
On the other hand, research on bioremediation, a technology for degrading and detoxifying pollutants in the environment using the microbial decomposition activity, has been progressing, and recently it has been applied to contaminated soil and contaminated groundwater. .
[0004]
Here, for soil and groundwater treated with microorganisms, it is necessary to examine whether or not the concentration of the pollutant is below a desired value by analyzing this, but the concentration of such volatile organic compounds is analyzed. As a simple method, contaminated soil or contaminated groundwater is used as a sample, and the sample is put in a container and sealed, and then this is shaken and stirred to volatilize contaminants in the sample between air and hollow in the container. Later, there is a method of analyzing the concentration of contaminants volatilized between the air and the air with an analytical instrument such as a gas chromatograph. By using such a portable analytical instrument, the sample is not brought back to the laboratory. In both cases, it is possible to measure the concentration of pollutants at the soil survey site and purification site.
[0005]
[Problems to be solved by the invention]
However, in the measurement method described above, when shaking and stirring, the contact between the microorganisms living in the sample and the contaminants remaining in the sample is promoted, and sufficient oxygen is added to the microorganisms by stirring. The degradation activity of the microorganism is increased.
[0006]
Therefore, the contaminants in the sample are decomposed during shaking and stirring due to the decomposition activity of the microorganisms, and at the stage of analysis with an analytical instrument, a value lower than the actual contaminant concentration appears, and the contaminants There has been a problem that there is a concern that a judgment is mistaken when evaluating a situation where the concentration is degraded and the concentration is lowered.
[0007]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a pollutant concentration measurement method capable of accurately grasping a decrease in the concentration of a pollutant.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a method for measuring the concentration of a pollutant according to the present invention includes a measurement object obtained by decomposing a pollutant by microbial decomposition activity as a sample, A liquid mixture composed of a predetermined microbial activity terminator is put in a predetermined container and sealed, and in this state, the container is shaken to stir the liquid mixture in the container, and left for a predetermined time, and then the container The concentration of the pollutant volatilized between the air cavities is analyzed.
[0010]
Moreover, the pollutant concentration measuring method according to the present invention uses the volatile organic compound as the pollutant and benzalkonium chloride as the microbial activity terminator.
[0011]
In the method for measuring the concentration of pollutants according to the reference invention , first, a measurement object in which the pollutants are decomposed by the microbial decomposition activity is used as a sample, and a mixed solution composed of the sample and acidic water or alkaline water is used in a predetermined container. Put inside and seal tightly.
[0012]
Next, the container mentioned above is shaken in this state, and the liquid mixture in this container is stirred.
[0013]
Next, after allowing to stand for a predetermined time, the concentration of contaminants volatilized between the air and hollow in the container is analyzed.
[0014]
In this way, since the microorganisms in the sample are placed in an acidic or alkaline environment, the degradation activity against the contaminants is reduced or substantially eliminated. Therefore, there is no possibility that the contaminants in the sample are decomposed by the decomposition activity of the microorganism while the mixed solution in the container is stirred in the shaking step.
[0015]
As the measurement object, for example, treated soil or treated groundwater obtained by decomposing a pollutant in contaminated soil or contaminated groundwater by microbial decomposition can be considered.
[0016]
As a specific example of the pollutant, volatile organic compounds, particularly trichlorethylene, can be considered.
[0017]
It is desirable that the standing time of the container after shaking is a time until the volatilization amount of the pollutant in the container and the penetration amount into the underwater space reach an equilibrium state.
[0018]
In the method for measuring the concentration of contaminants according to the present invention , first, a measurement object in which contaminants have been decomposed by microbial decomposition activity is used as a sample, and a mixed solution comprising the sample, water, and a predetermined microbial activity terminator is prepared. Put in a container and seal tightly.
[0019]
Next, the container mentioned above is shaken in this state, and the liquid mixture in this container is stirred.
[0020]
Next, after allowing to stand for a predetermined time, the concentration of contaminants volatilized between the air and hollow in the container is analyzed.
[0021]
When it does in this way, the decomposition activity of the microorganisms in a sample will fall with a microbial activity terminator. Therefore, there is no possibility that the contaminants in the sample are decomposed by the decomposition activity of the microorganism while the mixed solution in the container is stirred in the shaking step.
[0022]
As the measurement object, for example, treated soil or treated groundwater obtained by decomposing a pollutant in contaminated soil or contaminated groundwater by microbial decomposition can be considered.
[0023]
Specific examples of pollutants may be volatile organic compounds, particularly trichlorethylene, and a specific example of a microbial activity terminator may be benzalkonium chloride.
[0024]
It is desirable that the standing time of the container after shaking is a time until the volatilization amount of the pollutant in the container and the penetration amount into the underwater space reach an equilibrium state.
[0025]
The liquid mixture is sufficient if the sample, water, and microbial activity terminator are mixed in the container before shaking, and a mixture of water and microbial activity terminator may be put in the container in advance. You may make it put them in a container separately.
[0026]
In addition, when it says the decomposition activity of microorganisms by this invention, not only the decomposition ability of the degradation enzyme which microorganisms have but the activity of microorganisms itself shall be included.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a pollutant concentration measuring method according to the present invention will be described below with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.
[0028]
( Reference example )
[0029]
FIG. 1 is a diagram showing a processing procedure of a pollutant concentration measuring method according to a reference example . As shown in the figure, in the pollutant concentration measuring method according to this reference example , first, as shown in FIG. Put in.
[0030]
Sample 1 was subjected to a predetermined time to inspect how the concentration of trichlorethylene decreases with the passage of time when degrading contaminated soil contaminated with trichlorethylene as a pollutant with the decomposition activity of microorganisms. Use the one extracted from the contaminated soil each time. In addition, when the sample 1 contains a piece of wood or gravel exceeding 5 mm, these are removed in advance.
[0031]
Next, as shown in FIG. 1 (b), acidic water or alkaline water 4 is put in the container 3, and a mixed solution 5 is prepared together with the sample 1. Here, if acidic water is used, for example, hydrochloric acid may be added to water to reduce the pH. If alkaline water is used, for example, sodium hydroxide is added to water to increase the pH. do it.
[0032]
Next, the mouth of the container 3 is sealed with a stopper 6.
[0033]
Next, in this state, the container 3 is shaken as shown in FIG. 1 (c), and the mixed solution 5 in the container is stirred.
[0034]
Next, after standing for a predetermined time, as shown in FIG. 1 (d), the concentration of trichlorethylene 7 volatilized between the air and hollow in the container 3 is analyzed using a portable gas chromatograph. The standing time of the container after shaking is preferably a time until the volatilization amount of trichlorethylene into the air space and the penetration amount into the underwater space reach an equilibrium state.
[0035]
In this way, since the microorganisms in the sample 1 are placed in an acidic or alkaline environment, the degradation activity on trichlorethylene is reduced or substantially eliminated.
[0036]
As described above, according to the pollutant concentration measuring method according to the present reference example , the mixed liquid 5 composed of the sample and the acidic water or the alkaline water 4 is put in the container 3 using the microorganism-treated soil as the sample 1. Sealed and shaken the container 3 in such a state to stir the mixed solution 5 in the container, left to stand for a predetermined time, and then analyzed the concentration of trichlorethylene 7 volatilized between the air and hollow in the container 3. Therefore, the microorganisms in the sample 1 are placed in an acidic or alkaline environment, and the degradation activity for trichlorethylene is reduced or substantially eliminated.
[0037]
Therefore, while stirring the mixed solution 5 in the container 3 in the shaking step, there is no possibility that the trichlorethylene in the sample 1 is decomposed by the decomposition activity of the microorganism, and as a result, the sample is being stirred during the conventional stirring. Trichlorethylene is decomposed by the degradation activity of microorganisms that live in the area, and at the stage of analysis, there is no concern that the value will be lower than the actual pollutant concentration, and as a result, trichlorethylene is decomposed and removed. It is possible to prevent a situation in which the determination of the progress of the concentration decrease is erroneous.
[0038]
( Embodiment )
[0039]
Next, a method for measuring the concentration of contaminants according to this embodiment will be described.
[0040]
FIG. 2 is a view showing a processing procedure of the pollutant concentration measuring method according to the present embodiment. As shown in the figure, in the pollutant concentration measuring method according to the present embodiment, first, as shown in FIG. Put in.
[0041]
Sample 1 was subjected to a predetermined time to inspect how the concentration of trichlorethylene decreases with the passage of time when degrading contaminated soil contaminated with trichlorethylene as a pollutant with the decomposition activity of microorganisms. Use the one extracted from the contaminated soil each time. In addition, when the sample 1 contains a piece of wood or gravel exceeding 5 mm, these are removed in advance.
[0042]
Next, as shown in FIG. 2 (b), water 11 is put into the container 3 and the microbial activity terminator 2 is added into the container to prepare a mixed solution 5 a together with the sample 1. Here, the microbial activity terminator 2 does not inhibit the elution of trichlorethylene from the sample 1, and sterilizes the microorganisms administered in the sample 1 for the degradation of trichlorethylene or reduces the degradation activity thereof. What is necessary is just to select suitably from what can. For example, it is desirable to use benzalkonium chloride as the microbial activity terminator 2.
[0043]
Next, the mouth of the container 3 is sealed with a stopper 6.
[0044]
Next, in this state, the container 3 is shaken as shown in FIG. 2 (c), and the mixed solution 5a in the container is stirred.
[0045]
Next, after allowing to stand for a predetermined time, as shown in FIG. 2 (d), the concentration of trichlorethylene 7 volatilized between the air and hollow in the container 3 is analyzed using a portable gas chromatograph. It is desirable that the standing time of the container 3 after shaking is a time until the volatilization amount of the trichlorethylene in the container 3 into the air space and the penetration amount into the underwater space reach an equilibrium state.
[0046]
In this way, since the microorganisms in the sample 1 have degraded activity due to the microorganism activity terminator 2, the trichlorethylene in the sample 1 is the microorganisms while the mixed solution 5a in the container 3 is shaken. There is no risk of degradation due to degradation activity. Moreover, since the microbial activity terminator 2 does not inhibit the elution of trichlorethylene from the sample 1, there is no concern that the concentration measurement of trichlorethylene will be hindered.
[0047]
As described above, according to the pollutant concentration measuring method according to the present embodiment, the mixed liquid 5a composed of the sample, water 11 and the microorganism activity terminator 2 is contained in the container 3 using the microorganism-treated soil as the sample 1. Put the container tightly, shake the container 3 in this state, stir the mixed solution 5a in the container, let stand for a predetermined time, and then analyze the concentration of trichlorethylene 7 volatilized between the air and hollow in the container 3 Therefore, the decomposition activity of the microorganisms in the sample 1 is lowered by the microorganism activity terminator 2.
[0048]
Therefore, while stirring the mixed solution 5a in the container 3 in the shaking step, there is no possibility that the trichlorethylene in the sample 1 is decomposed by the decomposition activity of the microorganisms. Trichlorethylene is decomposed by the degradation activity of microorganisms that live in the area, and at the stage of analysis, there is no concern that the value will be lower than the actual pollutant concentration, and as a result, trichlorethylene is decomposed and removed. It is possible to prevent a situation in which the determination of the progress of the concentration decrease is erroneous.
[0049]
【The invention's effect】
As described above, according to the method for measuring the concentration of contaminants according to the present invention, the microorganisms in the sample are degraded in degradation activity by acidic water, alkaline water or a microbial activity terminator.
[0050]
Therefore, while stirring the liquid mixture in the container in the shaking process, the contaminants in the sample are not decomposed by the microbial decomposition activity, and the sample is inhabited during stirring as in the past. Contaminants are decomposed by the decomposition activity of microorganisms, and there is no concern that the value will be lower than the actual pollutant concentration at the stage of analysis. As a result, the contaminants are decomposed and removed, and the concentration decreases. It is possible to prevent situations such as misjudgment of the situation that is going on.
[0051]
[Brief description of the drawings]
FIG. 1 is a view showing a processing procedure in a pollutant concentration measurement method according to a first embodiment.
FIG. 2 is a view showing a processing procedure in a pollutant concentration measurement method according to a second embodiment.
[Explanation of symbols]
1 Sample 2 Benzalkonium chloride (microbe activity terminator)
3 Container 4 Acidic or alkaline water 5,5a Mixture 7 Trichlorethylene (volatile organic compound, pollutant)
11 Water

Claims (2)

  Using a measurement object in which contaminants have been decomposed due to the decomposition activity of microorganisms as a sample, a mixture of the sample, water, and a predetermined microbial activity terminator is placed in a predetermined container and sealed, and in this state the container The method for measuring the concentration of contaminants is characterized by analyzing the concentration of the contaminants volatilized between the air cavities in the container after stirring the liquid mixture in the container and allowing to stand for a predetermined time. .   The pollutant concentration measuring method according to claim 1, wherein the pollutant is a volatile organic compound, and the microbial activity terminator is benzalkonium chloride.

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