JPH0972898A - Analyzing method for soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply and rapidly measuring contaminant substance even at the site by adding and mixing extract to and with sampled soil to analyze the soil, then efficiently separating the mixed liquid, easily obtaining the liquid to be extracted which can be measured without abnormal value even it is measured. SOLUTION: The method for analyzing soil has the steps of adding and mixing extract to and with the sampled coil, and then analyzing the liquid to be extracted obtained by separating the mixed liquid of the soil and the extract, and comprises the steps of adding the extract to the soil to extract the contaminant substance in the soil, then adding flocculant containing no contaminant substance to the contaminant substance to be measured, thereby expediting the separation of the liquid to be extracted from the mixed liquid of the soil and the extract, and further simply and rapidly measuring the contaminant substance of the liquid to be extracted by a simple analyzing method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil analysis method, and more particularly to a method for extracting pollutants from soil and a simple method for on-site analysis of the extracted pollutants.

[0002]

2. Description of the Related Art Recently, soil pollution has become a major environmental problem. In particular, pollutants such as inorganic substances, heavy metals, PCBs, pesticides and organic chlorine compounds have become a problem. Contaminated soil must be rehabilitated in order to make effective use of the land, but rehabilitation of soil is extremely expensive and the rehabilitation area is usually kept as small as possible. For this purpose, soil surveys must be carried out, and the identification of pollutants, the extent of contamination, and the extent of soil contamination (area and depth) must be evaluated as accurately as possible.

[0003] Soil analysis is usually carried out by boring the soil at the site, bringing the soil back to the laboratory, sampling a certain amount of soil in a container, and dissolving and extracting the measured components of this soil ( (Hereinafter referred to as "extract") is added and mixed, and then the mixture is allowed to stand, centrifuge, natural filtration or forced filtration, and then the liquid obtained by separating unnecessary and disturbing components from the mixture ( Hereinafter referred to as the liquid to be extracted)
Atomic absorption method, ICP emission spectral analysis method, ICP-mass spectrometry method, absorptiometric method (spectrophotometer method), fluorometric method, gas chromatograph method, gas chromatography mass spectrometry method, ion chromatograph method, liquid chromatography It is performed by measuring with an instrumental analyzer such as a graph method. In the series of analyzes described above, there is a demand for a method that can be performed easily and with high efficiency, obtains highly sensitive and highly accurate results, and is low in cost.

Soil which may be polluted is
Boring is performed by dividing the local land into meshes having an interval of 5 m or 30 m, for example, and the soil is sampled on the surface of the center soil and in the depth direction. Depending on the method and soil quality, boring can be done only once or several times a day, so if the area of land to be surveyed is large,
Since the number of soil samples is large, it takes a lot of days just to collect the soil, which results in a large amount of cost, and the analysis cost increases depending on the number of samples to be measured. Therefore, in order to save soil investigation costs as much as possible, it is necessary to collect uncontaminated soil as little as possible and reduce the number of samples. To do this, the soil sampled must be rapidly analyzed and the results used to determine whether to continue drilling. That is, it is required to analyze soil easily, quickly, with high accuracy and at low cost while collecting soil.

Therefore, the measurement of the pollutants of water and the liquid to be extracted does not use a large-scale instrumental analyzer which is required to be installed in the above-mentioned laboratory, and the operation and conditions on the way are simplified to simplify the device. Simple analytical methods have also been used to save labor, equipment and time. Examples of this simple analytical method include, for example, a pack test (Kyoritsu) of a simple water quality tester and a reagent for a quick water quality tester in the column of water quality tester in the scientific equipment general catalog ('95 / '96 edition-publisher: Fine group). "Kyoritsu" method using a reagent for rapid water quality meter and spectrophotometer, and Yoshitest as a contaminated water quality simple tester,
Further, the HACH method (using the PAS method multi-item rapid water quality / soil / food analyzer), the Ponard kit method, the immunoassay method, the portable gas chromatograph method and the like can be mentioned.

[0006]

Soil has various soil types, for example, gravel, gravel soil, sand, sandy soil, silt,
Cohesive soil, organic soil, volcanic ash cohesive soil, and high organic soil. In the actual soil, these are mixed and form a complicated soil quality. Soil is larger than 1 mm with large particles of 0.1.
Widely distributed up to fine particles of 1 μm or less. In this way, after adding the extract to the soil sample and mixing, the extract to be extracted is collected by standing or filtering, but especially fine-grained soil is difficult to settle, and when filtering the mixture of soil and extract. Easy to pass through the filter. As a result, the separation of the mixed liquid of the soil and the extract becomes incomplete, and many fine particles of soil remain in the liquid to be extracted separated from the mixed liquid and become turbid, and the turbidity of the liquid to be extracted becomes high. If the pore size of the filter is made small in order to completely capture the fine particles, it takes a long time for the natural filtration. In addition, depending on the soil, it may not be possible to separate the mixed liquid of the soil and the extract at all even after spending all day and night, and forced filtration such as suction filtration is performed.However, it may take a long time, so centrifuge first. After doing, you have to do the filtration.

As described above, conventionally, a large amount of labor and a long time is required to obtain the liquid to be extracted by separating the soil and the extraction liquid, and further, a large-scale device such as a centrifuge or a forced filtration device is required. I was there. In addition, if the liquid to be extracted cannot be separated from this mixed solution well, it may show an abnormally high value depending on the analysis target component when measuring contaminants in the liquid to be extracted, or it may not be possible depending on the analysis method. There was a problem. In particular, when the turbidity of the liquid to be extracted becomes 50 degrees or more, the value fluctuates and the measurement cannot be performed by the spectrophotometer, or the injection hole of the liquid to be extracted of the measuring instrument is clogged and the ICP-emission spectrophotometer or atomic absorption spectrometry is used. I can not measure with the device,
There is also a problem that the element of the main component of the soil is detected and the trace analysis of the target pollutant cannot be performed at all.

Further, since it is difficult to bring the above-mentioned large-sized instrumental analysis device to the site for analyzing soil at the site, the above-mentioned simple analysis method is applied as an alternative method. In that case, the analysis step adds the extract to the soil,
After mixing, the liquid to be extracted obtained by separating the mixed liquid of soil and extract will be subjected to a simple analysis method. In order to carry out this whole process quickly, the liquid to be extracted must be obtained easily, quickly and at low cost. If a large amount of labor is spent for a long time to obtain the liquid to be extracted, the initial purpose cannot be achieved.

The object of the present invention is to measure the elution amount and / or content of pollutants in soil. Therefore, after adding and mixing the extract to the sampled soil, the mixture is efficiently separated for measurement. It is an object of the present invention to provide an extraction method by which a liquid to be extracted can be easily obtained with high accuracy and precision even when provided. Another object of the present invention is to provide a method for measuring pollutants easily, quickly and accurately at a low cost on site.

[0010]

In order to solve the above-mentioned problems, the present invention is obtained by adding and mixing an extract to the sampled soil, and then separating the mixed solution of this soil and the aforementioned extract. In the soil analysis method for analyzing a liquid to be extracted, after the extract is added to the soil, the coagulant containing no pollutant is added to the pollutant for the measurement purpose, whereby the soil and the extract are separated. It is characterized by accelerating the separation of the liquid to be extracted from the mixed liquid.

Further, in order to measure pollutants easily, quickly and at low cost and with high accuracy in the field, the present invention adds the extract solution to the sampled soil and mixes it with each other. In a soil analysis method for analyzing a liquid to be extracted obtained by separating a mixed liquid, a flocculant containing no pollutant is added to the pollutant to be measured after the extract is added to the soil. This facilitates the separation of the liquid to be extracted from the mixed liquid of the soil and the liquid to be extracted, and the contaminant in the liquid to be extracted is measured by a simple analysis method.

That is, the greatest feature of the present invention is that, when an extract is added to soil and mixed, and then a specific flocculant is present when the extract is separated from the soil, mixing is performed, which is troublesome and time-consuming. A liquid to be extracted that can be provided for measurement without contaminating the liquid to be extracted by promoting the separation of the liquid to be extracted from the mixed liquid of the soil and the liquid without performing the filtration step and / or the centrifugal separation step. That is, even if this flocculant is added, the contaminants dissolved in the mixed solution cannot be removed by flocculation and precipitation. A feature of the present invention is that the liquid to be extracted can be easily and quickly analyzed on site.
With this configuration, the turbidity of the liquid to be extracted obtained by separation can be set to 50 degrees or less.

The pollutants targeted in the analysis method of the present invention include inorganic substances, organic substances, heavy metals and the like. Inorganic substances include, for example, cyanide, ammonia, nitrate ions, etc., organic substances include PCB, agricultural chemicals, organic chlorine compounds, etc., and heavy metals include hexavalent chromium, mercury,
Examples of the contaminant include nickel, copper, lead, arsenic, cadmium, selenium, beryllium, vanadium, antimony, and zinc, but the pollutants targeted by the present invention are not limited thereto.

In the present invention, the extract used for these contaminants is pure water, 0.01 to 10 N hydrochloric acid,
Acidic liquids such as nitric acid and sulfuric acid, 0.01-10N caustic soda, alkaline liquids such as ammonia water, aliphatic hydrocarbon compounds such as hexane and heptane, ethers such as ethyl ether, alcohols such as methanol and ethanol, etc. Organic solvents include, but are not limited to.
Preferably, purified water containing no impurities such as metals and organic substances, diluted hydrochloric acid, diluted nitric acid, diluted caustic soda, hexane,
They are aliphatic hydrocarbon compounds such as heptane, alcohols such as methanol and ethanol, and mixed solutions thereof. The amount of extract added depends on the soil properties, but generally 1 ml to 100 m per 1 g of sampled soil.
The optimum range is 1, preferably 2 ml to 50 ml.

As the coagulant that can be used in the extraction of the present invention, there are an inorganic coagulant and an organic coagulant, and the coagulant that does not contain the pollutant and has no adverse effect on the pollutant to be measured. Anything may be used as long as it is used.
Organic coagulants are used when measuring inorganic pollutants and heavy metals, and inorganic coagulants and organic coagulants are used when measuring organic pollutants. An organic coagulant is preferable as the coagulant.

Among the coagulants, as the inorganic coagulant, for example, sulfuric acid band, ferrous sulfate, ferric sulfate, ferric chloride, sodium aluminate, polyaluminum chloride can be used, and organic coagulant. There are surfactants and polymer flocculants. Examples of the polymer flocculant include sodium alginate, CMC-sodium, water-soluble aniline resin hydrochloride, polythiourea hydrochloride, water-soluble cationized amino resin, starch, gelatin, water-soluble urea resin, sodium polyacrylate, polyacrylamide. Partial hydrolysates, polyvinylpyrine hydrochloride, polyethyleneimine, polyacrylamide cation modified, polyacrylamide, polyethylene oxide, polypropylene oxide and the like can be mentioned. The inorganic and organic coagulants may be used alone or as a mixture. Further, the amount of the flocculant added varies depending on the flocculant, the properties of the soil and the extract, but the concentration of the flocculant is set within the range of 1 ppm to 10%, preferably 10 ppm to 5% with respect to the extract.

Incidentally, the coagulant has heretofore been used for coagulating and separating fine suspensions in wastewater when purifying industrial wastewater, domestic wastewater and the like, and also for producing heavy metal ions which are difficult to drain in an aqueous solution. It has been used to insolubilize, precipitate and remove. However, in the present invention, unlike the method of using the coagulant that has been conventionally used, the substance contained in the aqueous solution which is unnecessary for measurement and which interferes in the measurement is deposited to leave only the necessary substance in the aqueous solution, Introducing a completely new method of using a flocculant that was not possible in the past,
It is the novel and progressive technical concept of the present application to make it very easy to facilitate the separation of the liquid to be extracted in the measurement of pollutants.

In accordance with the above description, the appropriate extract and flocculant is selected for the soil contaminants being analyzed.
Then, after mixing the soil and the extract, a flocculant is added, and the mixture is gently stirred for a certain period of time or the like. Then, the mixture is left to stand and the supernatant of the mixed solution is collected or filtered, or in a specific case, the mixed solution of the soil and the extract is separated by a method such as centrifugation. By adding the coagulant, it is possible to easily separate the liquid to be extracted from the mixed liquid of the soil and the extraction liquid by simply allowing it to stand still, and stable measurement results can be obtained in the subsequent measurement.

Turbidity is a measure of the degree of turbidity of a liquid and is defined in JIS K0101. According to this, the visual turbidity, transmitted light turbidity, scattered light turbidity, and integrated sphere turbidity are displayed separately. For example, in the case of integrated sphere turbidity, the turbidity of 1 mg / l kaolin is defined as the turbidity of 1 degree by obtaining the ratio of the intensity of the scattered light by the particles in the liquid and the intensity of the transmitted light.

As described above, the soil is widely distributed from large particles of 1 mm or more to fine particles of 0.1 μm or less. Especially, fine particle soil is unlikely to settle and easily permeates through the filter when filtering the mixed solution. . If the separation from the mixed liquid is incomplete, many fine particles remain in the liquid to be extracted, and the turbidity of the liquid to be extracted becomes high.

In the measurement of pollutants in soil, ultra-trace analysis in units of ppm to ppb is required as the lower limit of quantification. In order to perform such highly accurate and highly sensitive measurement, the turbidity of the liquid to be extracted needs to be 50 degrees or less, preferably 30 degrees or less. If the turbidity is 50 degrees or more, for example, when measuring contaminants with a spectrophotometer, the measured value shows an abnormal value, or when performing other device analysis, when the liquid to be extracted is injected into the device, the injection hole is clogged. Measurements cannot be made due to problems such as being lost.

For the measurement of the liquid to be extracted from which the pollutant has been extracted, an optimum method for the target component may be selected. As the analysis method, for example, absorptiometry, fluorescence spectrophotometry, atomic absorption spectrometry, ICP-emission spectroscopy, ICP-mass spectrometry, ion electrode, continuous flow and flow injection analysis, ion chromatography, high performance liquid chromatography Method, gas chromatography method, gas chromatography mass spectrometry method and the like, but of course the invention is not limited thereto. As a simple analysis method to be performed locally, for example,
Simple water quality tester-pack test (Kyoritsu), "Kyoritsu" rapid water quality reagent-method using spectrophotometer, Yoshitest, HACH method (PAS method multi-item rapid water quality / soil / food analyzer), Ponard kit method, Examples include, but are not limited to, immunoassay methods and portable gas chromatographic methods.

[0023]

Examples of the present invention will be described below. The present invention is not limited to these. Example 1: 5 g of soil collected at a depth of 3 m from the surface of the former site of the A factory was weighed and placed in a container, and 50 ml of 0.1N hydrochloric acid was added.
And shaken vigorously for 2 minutes. Then, an aqueous solution of Sumifloc FN-10H (polyacrylamide polymer flocculant) manufactured by Sumitomo Chemical as a flocculant (0.001 g / ml)
1.5 ml was added and gently stirred for 1 minute. After standing still for 1 minute, the supernatant was collected by a gradient method to obtain a liquid to be extracted. The turbidity of the liquid to be extracted was measured with an integrating sphere turbidimeter (SEP-PT205 type manufactured by Mitsubishi Kasei Co., Ltd.).
It was 4.0 degrees. The amount of suspended solids (SS) is 7.0 mg
/ L. Zinc (Zn), iron (Fe), copper (Cu), and hexavalent chromium (Cr) of this liquid to be extracted were measured with an ICP emission spectrophotometer to obtain 2.6 mg / l and 28.0, respectively.
It was mg / l, 5.1 mg / l, and 0.01 mg / l.

Comparative Example 1: An extraction liquid was separated from a mixed liquid of soil and an extraction liquid by a method according to the official method. As in Example 1, 5 g of soil collected at a depth of 3 m from the surface of the site of the factory A was weighed and put in a container, and 0.1 N hydrochloric acid 50
ml was added and shaken vigorously for 2 minutes. After standing for 1 hour, centrifugation was performed at a rotation speed of 2000 rpm for 10 minutes. Further, forced filtration was carried out for 5 minutes using a syringe equipped with a filter having a pore size of 0.45 μm. The turbidity of this liquid to be extracted was 23.0 degrees, and the amount of suspended solids was 7.0 mg / l.
When zinc, iron, copper and hexavalent chromium are measured, they are 2.7 mg / l, 27.7 mg / l, 5.2 mg / l and 0.0, respectively.
It was 1 mg / l. From the above results, it is understood that the method of Example 1 gave the same analytical value within the error range as compared with the method based on the official method.

Comparative Example 2 As in Example 1, 5 g of soil collected from the surface of the former site of Factory A at a depth of 3 m was weighed and placed in a container, and 50 ml of 0.1N hydrochloric acid was added and shaken vigorously for 2 minutes. . After standing for 1 hour, the mixture was naturally filtered through a filter having a pore size of 0.45 μm for 6 hours. The turbidity of this liquid to be extracted was 75.0 degrees, and the amount of suspended solids was 29.0 mg / l. When zinc, iron, copper and hexavalent chromium are measured, they are 3.0 mg / l, 33.2 mg / l, 5.7 mg / l and 0.0, respectively.
It was 2 mg / l.

Comparative Example 3: As in Example 1, 5 g of soil sampled at a depth of 3 m from the surface of the site of Factory A was weighed and placed in a container, 50 ml of 0.1N hydrochloric acid was added, and the mixture was shaken vigorously for 2 minutes. . After standing for 10 minutes, the supernatant was collected by the gradient method as in Example 1 to obtain a liquid to be extracted. The turbidity of the liquid to be extracted was 450 degrees or more, and the amount of suspended matter was 750 mg / l or more. In addition, zinc, iron, copper and hexavalent chromium could not be measured.

Example 2: Sumiflon FN-20H manufactured by Sumitomo Chemical Co., Ltd. different from the one used in Example 1 as a flocculant
(Polyacrylamide-based polymer flocculant) aqueous solution (0.
Example 1 except that 1.0 ml of (001 g / ml) was added.
I went the same way. The turbidity of this liquid to be extracted was 23.0 degrees, and the amount of suspended solids was 8.0 mg / l. Also zinc, iron,
When copper and hexavalent chromium are measured, 2.6 mg / l and 2 respectively
The amounts were 8.3 mg / l, 5.3 mg / l and 0.74 mg / l.

Example 3 The same procedure as in Example 1 was carried out except that the surface soil of another site of the B factory was used as a sample. The turbidity of the liquid to be extracted was 9.0 degrees, and the amount of suspended solids was 4.0 mg / l.
When zinc, iron, copper and hexavalent chromium are measured, they are 5.3 mg / l, 33.9 mg / l, 8.5 mg / l and 0.7, respectively.
It was 4 mg / l.

Comparative Example 4 As in Example 3, 5 g of surface soil on the site of the B factory was weighed and placed in a container, and 0.1 N hydrochloric acid 5 was added.
0 ml was added and shaken vigorously for 2 minutes. A liquid to be extracted was obtained in the same manner as in Comparative Example 1. The turbidity of this liquid to be extracted is 9.0.
The amount of suspended solids was 4.0 mg / l. Also zinc,
When iron, copper and hexavalent chromium are measured, each is 5.6 mg /
1, 33.7 mg / l, 8.0 mg / l, 0.75 mg / l.

Comparative Example 5: To 50 ml of 0.1 N hydrochloric acid, 1.5 ml of the polyacrylamide-based polymer flocculant aqueous solution used in Example 1 was added and gently stirred. The turbidity of this liquid was 1, and the amount of suspended solids was 1 mg / l or less. Also,
When measuring zinc, iron, copper, and hexavalent chromium, each is 0.0
It was 1 mg / l or less, and hexavalent chromium was 0.001 mg / l or less.

Example 4: A depth of 3 m from the surface of the former site of Factory A
Weigh 5g of soil sampled in step 2 and put it in a container.
1 was added and stirred for 4 hours. Thereafter, 0.5 ml of the polyacrylamide-based polymer coagulant aqueous solution used in Example 2 was added as a coagulant, and the mixture was gently stirred for 1 minute.
After standing for 1 minute, the supernatant was collected. The volatile organic substances in the liquid to be extracted were measured with a gas chromatography mass spectrometer equipped with a headspace sample introduction device. Chloroform (CHCl ₃ ), benzene (C ₆ H ₆ ), toluene (C
₆ H ₅ CH ₃ ) only 0.11 mg / l, 0.0
10 mg / l and 0.071 mg / l were detected.

Comparative Example 6 As in Example 4, 5 g of soil collected at a depth of 3 m from the surface of the former site of Factory A was weighed and placed in a container, 50 ml of pure water was added, and the mixture was stirred for 4 hours. After standing for 1 hour, the mixture was forcibly filtered for 5 minutes with a syringe equipped with a filter having a pore size of 0.45 μm. When the volatile organic substances of this liquid to be extracted were measured in the same manner as in Example 4, only chloroform, benzene and toluene each contained 0.12.
mg / l, 0.009 mg / l, 0.074 mg / l were detected.

[0033]

[Table 1]

As can be seen from Table 1 showing the examples according to the present invention and the corresponding comparative examples, in the comparative examples, the turbidity of the filtered liquid to be extracted is high, and the turbidity is low due to the combined use of the centrifugation step. You're getting value. On the other hand, according to the example of the present invention, the separation can be easily performed by adding the coagulant, and the turbidity of the liquid to be extracted obtained by this separation is low and the amount of pollutants is also low. You can get a reasonable value. That is, as is clear from comparison with the method according to the official method of Comparative Example 1, the analytical value obtained by the present application is equivalent to the analytical value of Comparative Example 1 within an error range, and is applied as a measured value. It is understood that this is possible.

Further, examples and comparative examples thereof by the simple analysis method will be described below. Example 5: A soil having a depth of 50 cm was collected from the ground surface at the site of the C factory, and 4 g of the soil was weighed on the site by a simple balance (personal electronic balance: manufactured by A & D Co., Ltd.) to form a container. , 40 ml of 1.0 N hydrochloric acid was added and shaken vigorously for 2 minutes. Then, 0.5 ml of the Sumifloc FN-10H aqueous solution used in Example 1 was added, and the mixture was gently stirred for 1 minute. After leaving still for 1 minute, the supernatant was collected by a gradient method to obtain a liquid to be extracted. The collected soil was brought back to the laboratory, and the turbidity of the liquid to be extracted obtained by performing the same operation as described above was 0.5 degree. Lead (Pb) measurements were performed on site according to the method using a "Kyoritsu" rapid water quality reagent-spectrophotometer. That is, 5N caustic soda was added to the liquid to be extracted obtained above to adjust the pH to 5 to 8, 25 ml was collected in a cell, 1 ml of a 5% KCN aqueous solution was added, and the mixture was stirred.
Then, 1 package of R-1 reagent according to the method is added and stirred,
After standing for 3 minutes, HACH SPECTROPHOTO
Lead was measured by METER DR / 2000. When the amount of caustic soda added is corrected and calculated, the lead concentration in the liquid to be extracted is 0.
It was 7 mg / l.

Comparative Example 7: In the same manner as in Example 5, soil having a depth of 50 cm was sampled from the surface of the site of the C factory, and the soil 4 was collected on site.
Weigh g with a simple balance and put it in a container.
0 ml was added and shaken vigorously for 2 minutes. After standing for 10 minutes, the supernatant was collected by the gradient method as in Example 5 to obtain a liquid to be extracted. In the same manner as in Example 5, the liquid to be extracted was subjected to an on-site measurement of lead (Pb) in accordance with a method using a "Kyoritsu" reagent for rapid water quality meter-spectrophotometer. However, the transmitted light intensity was too weak to measure. The extracted soil was brought back to the laboratory, and the turbidity of the liquid to be extracted obtained by performing the same operation as described above was 90 degrees.

Experimental Example 6: Lead was measured in the same manner as in Example 5 except that the surface soil collected at another place of the C factory was used as a sample and the lead was measured to be 1.1 mg / l. In addition, the turbidity of the liquid to be extracted obtained by carrying out the same operation as the operation to obtain the liquid to be extracted by bringing the collected soil back to the laboratory was 3.1 degrees. The lead in this liquid to be extracted was measured by ICP-emission spectroscopy and found to be 1.0 mg / l.

Example 7: As an aggregating agent, an aqueous solution (0.006) of Sumifloc FA-50 (polyacrylamide polymer aggregating agent) manufactured by Sumitomo Chemical Co., Ltd. different from the one used in Example 6 was used.
(1 g / ml) 0.5 ml was added, and the same procedure as in Example 6 was carried out. The lead concentration of this liquid to be extracted is 1.
It was 2 mg / l.

Example 8: Soil on the surface of the ground was collected at the site of the D factory, and 4 g of the soil was weighed in a simple balance and put in a container.
40 ml of 1.0 N hydrochloric acid was added and shaken vigorously for 2 minutes. After that, Sumifloc FN-10H aqueous solution 0.5m
1 was added and gently stirred for 1 minute. After standing for 1 minute, the supernatant was collected by a gradient method to obtain a liquid to be extracted. Lead (Pb) was measured in the field according to the Yoshitest method. 5N caustic soda was added to the liquid to be extracted,
After adjusting H to 3 to 8, this liquid to be extracted was finally diluted 5-fold with distilled water. Then, add the liquid (3) to a 3 ml test tube, add 3 tablespoons of the additive (1), shake well to dissolve, then add 2 drops of the addition liquid (2), shake well, and add the addition liquid (3). Add 3 drops and shake well. After confirming that the pH was 4 to 6, a dropper was attached to the detection tube, and it was sucked up to red at a constant speed. The measurement value was read by comparing the length of the colored layer (red-orange) of the detector tube with the lead ion standard concentration. Calculated by correcting the dilution factor, the lead concentration in the liquid to be extracted is 10 mg.
/ L.

Comparative Example 8: The soil sampled from the surface of the site of the D factory similar to that of Example 8 was brought back to the laboratory and measured in the laboratory. 5 g of soil was weighed and put in a container, 50 ml of 1.0N hydrochloric acid was added, and the mixture was vigorously shaken. After standing for 1 hour, centrifugation was performed at a rotation speed of 2000 rpm for 10 minutes. Further, forced filtration was performed for 5 minutes using a syringe equipped with a filter having a pore size of 0.45 μm. This liquid to be extracted is I
Lead (Pb) measured by CP-emission spectroscopy is 11 mg
/ L.

Example 9: At the site of the E factory, soil on the surface of the earth was sampled, 4 g of the soil was weighed in a container by a simple balance, put in a container, and 40 ml of 1.0 N hydrochloric acid was added and shaken vigorously for 2 minutes. After that, 0.5% Sumifloc FN-10H solution was added.
ml was added and gently stirred for 1 minute. After standing for 1 minute, the supernatant was collected by a gradient method to obtain a liquid to be extracted. P
Hexavalent chromium (Cr ⁶⁺ ) was measured on site according to the measurement manual (1,5-diphenylcarbohydrazide method) of the AS method multi-item rapid water quality / soil / food analysis method. The hexavalent chromium concentration of the liquid to be extracted was 0.55 mg / l.

As can be seen from Example 5 onward according to the present invention and the corresponding Comparative Examples 7 and 8, the turbidity of the filtered liquid to be extracted is high in Comparative Example 7, and the measurement can be performed as it is. could not. Further, in Comparative Example 8, a low value is obtained by applying the coagulant according to the present invention. In addition, in the examples of the present invention, the separation can be easily performed by adding a coagulant, and the turbidity of the liquid to be extracted obtained by this separation is low and the amount of pollutants is also a reasonable value. Therefore, even if the simple analysis method is applied to the liquid to be extracted, a reasonable value can be obtained within the error range. That is, as is clear from comparison with Comparative Example 8, the measurement value obtained by the simple analysis method obtained by the present application is equivalent to the value measured by applying the large-sized analytical instrument of Comparative Example 8 within the error range. It is understood that these are applicable as measured values.

[0043]

EFFECTS OF THE INVENTION According to the present invention, when the extract is added to the sampled soil and the mixture is separated after mixing, the presence of the coagulant allows efficient extraction without the need for the filtration step and the centrifugation step. An extract can be obtained,
Contaminants in the liquid to be extracted can be easily and quickly measured on-site.

Claims (2)

[Claims] 1. A method of analyzing a liquid to be extracted obtained by adding and mixing an extract to a sampled soil and then separating a mixture of the soil and the extract, wherein the extract is added to the soil. After the addition, for the pollutant to be measured, a coagulant containing no pollutant is added to promote separation of the liquid to be extracted from the mixed liquid of the soil and the extract. Analysis method. 2. A method for analyzing a liquid to be extracted obtained by adding and mixing an extract to a sampled soil and then separating a mixture of the soil and the extract, wherein the extract is added to the soil. After the addition, by adding a coagulant that does not contain pollutants to the pollutants to be measured, separation from the mixture of soil and extract is promoted, and the pollutants in the extracted liquid are simplified. A soil analysis method characterized by being measured by an analysis method.