JPH0862205A - Simple measurement method for oil content in earth and sand containing oil - Google Patents

Abstract

PURPOSE: To provide a handy measurement method of oil content which make the oil content in an earth and sand containing oil to be found simply and quickly in a site of reforming the earth and sand containing oil. CONSTITUTION: Earth and sand speciments are sampled properly at a plurality of points in a zone of earth and sand containing oil to determine oil contents of the earth and sand specimens at respective sampling positons and a plurality of the earth and sand specimens different in oil content are selected from among the specimens in which oil content is determined. A fixed amount (A) of the specimens selected is dissolved into a fixed amount (C) of a chloroform solution with a fixed concentration (B) to compare respective brightness in the color presentation of the chloroform solution and the fixed amount (A) of the earth and sand specimens sampled at random from the zone of the earth and sand containing oil is dissolved into the fixed amount (C) of the chloroform solution with the fixed concentration (B) to compare the brightness in the color presentation of the chloroform solution. Thus, the oil content of the earth and sand specimens is dicided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily quantifying the oil content of oil in sediments impregnated with oils and fats such as lubricating oil and cutting oil.

[0002]

2. Description of the Related Art Oil-bearing soil weakens the bearing capacity of the ground and causes uneven settlement of building structures. Further, the oil in the soil and sand further diffuses the soil pollution due to the infiltration of rainwater, and finally flows into the groundwater together with the infiltrated water, causing groundwater pollution. As one of the methods for solving the problems caused by the oil-containing soil as described above, by adding an oil-containing hardening material to the excavated oil-containing earth and sand, the oil-containing oil is contained in the earth and sand, and the earth-and-sand containing the oil is buried. There is a way back. In adding the oil-impregnated hardener, an appropriate amount of oil-impregnated hardener must be added according to the oil content of each excavated earth and sand site. However, the oil content of the ground varies depending on conditions such as the range, amount, and geology of the oil that once leaked to the ground surface, and is not uniform, and consequently varies depending on the site in the ground. Therefore, in order to cure the oil-containing oil accurately, it is necessary to measure the oil-containing rate for each part of the excavated oil-containing soil. However, the oil species impregnated in the soil is due to the oil species that once leaked to the surface,
There are various types of oil such as mineral oil, lubricating oil, cutting oil, and fats and oils, and these types of oil are a mixture of various constituent oils. For this reason, when investigating the oil content of earth and sand in which it is unknown which constituent oil is impregnated, the n-hexane extraction method according to JIS K0102, which is used to calculate the oil content in environmental measurement with the current measurement technology, is used. I can't help it.

[0003]

[Problems to be Solved by the Invention] However, JIS
According to the n-hexane extraction method by K0102, the oil-impregnation extraction operation is complicated, and the oil-impregnation rate of one sample can be determined by 6
It takes about a long time. Therefore, JIS K01
It is unrealistic to measure the oil content of each part of excavating oil-containing soil by using the method of quantifying the oil content by n-hexane extraction method according to 02, and control the hardening condition of oil-containing soil. In the above, it was the current situation that the oil content was not measured although it was necessary. Therefore, in order to surely contain the oil-impregnated oil, an excessive amount of the oil-impregnated hardener has to be added, which is uneconomical. Further, if the amount of the oil-impregnated hardener that is considered to be appropriate according to the visual examination is added, the situation of insufficient addition may occur, and there is a problem that the oil-containing impregnated portions are scattered. Under these circumstances, in order to reliably and economically contain oil, the oil content of oil-containing soil can be easily and quickly measured at the oil-containing soil reforming site. Was eagerly awaited. The present invention has been made in view of the above circumstances, and an object thereof is to provide an oil content simple measurement method capable of easily and quickly knowing the oil content in the oil-containing earth and sand in the oil-containing earth-sand reforming site. To do.

[0004]

A method according to the above-mentioned object.
A simple method for measuring the oil content in the oil-containing soil described is to appropriately collect and collect sediment samples from a plurality of locations in the oil-containing soil band, quantify the oil content of the sediment sample at each sampling position, and to quantify the sediment sample. A plurality of earth and sand samples having different oil contents are selected from among them, and a certain amount (A) of the selected earth and sand samples is dissolved in a certain amount (C) of a chloroform solution having a constant concentration (B). Each of the lightness and a certain amount (A) of the sediment sample arbitrarily collected from the oil-bearing sediment band was dissolved in the certain amount (C) of the chloroform solution having the constant concentration (B) to give a color change of the chloroform solution. By comparing with the lightness, the oil content of the arbitrarily collected earth and sand sample is determined.

[0005]

[Function] Except for oil sand, natural soil does not originally contain oil. Oil is mixed with natural sediments because lubricants and cutting oils that have leaked from machinery, oil that has leaked at oil warehouses, waste oil storage areas, etc. Due to the inclusion. In the current measurement technology, the method of quantifying the oil content in these sediments has not been established. Therefore, the quantification of the oil content in the sediment is performed by the JIS-K1022-based n-hexane extraction method (hereinafter simply referred to as the n-hexane extraction method) for the purpose of quantifying the volatile mineral oil and animal and vegetable oils and fats contained in the factory effluent. ) Is diverted and is done for convenience. here,
Since the earth and sand itself is mainly composed of silicic acid, it is hardly soluble in n-hexane. In addition, animal and vegetable oils and fats that enter into the soil from animals and plants due to natural phenomena rather than artificial effects are in a small amount. And, the oil content artificially impregnated in the earth and sand includes oil that is easily volatilized, but the oil that is easily volatilized is the oil hardener from the time when the oil-containing earth and sand was dug out to add the oil hardener. Since most of it volatilizes before the addition of, the oil content does not have to be considered as an oil constituting the oil content for determining the addition amount of the oil curing agent. From these, it can be said that the oil content determined by the n-hexane extraction method is the oil content in soil itself.

Therefore, various samples having different oil contents are collected in advance from the earth and sand, and the oil contents contained in the samples are calculated for each sample by using the n-hexane extraction method. By doing so, various samples with known oil contents can be obtained. N- as a medium liquid in oil-containing extraction
Hexane is used because it has a high dissolving power for oil, a low boiling point, and is easily separated from oil.
In addition to n-hexane, a solvent having a large dissolving power for oil is chloroform. Chloroform dissolves a wide range of organic compounds such as fats, mineral oils, waxes, alkaloids, resins, rubbers, tars, etc. and is hardly soluble in silicic acid, which is the main component of earth and sand. The degree of color of the chloroform solution has a high degree of correlation with the oil content calculated using the n-hexane extraction method.

When an oil is dissolved in chloroform, the chloroform solution turns red and the brightness of the color depends on the concentration of the dissolved oil. Therefore, if the color development of chloroform in a sample with a known oil content is prepared in advance as a color sample, the oil content can be determined by comparing the color sample with the color development of chloroform obtained from a sample with an unknown oil content. You can know. Further, when each of the above-mentioned various samples having different oil contents is dissolved in chloroform under a certain condition, the chloroform solution also exhibits a red color, and the lightness of the color also varies depending on the difference in oil content. The red color differs slightly depending on the type of oil impregnated, but since the difference is in the same color system, it does not change depending on how the optic nerve is felt due to individual differences, and it is common for each person. It's something to feel. Therefore, the difference in lightness of the color of the chloroform solution due to the same oil type relatively represents the difference in the concentration of the dissolved oil.

Generally, the oil content in the earth and sand is artificially mixed, and from the process of mixing, the constituent oil species of oil-containing oil in the same oil-containing earth and sand belt and their mixing ratio are substantially the same. is there. Therefore, in the same oil-bearing earth and sand band, the chloroform solution in which the oil-bearing is dissolved exhibits a color according to the constituent oil species of the oil-bearing, and the lightness of the color is different depending on the oil-bearing rate. Therefore, the oil content in the same oil-bearing soil band can be known from the difference in lightness of the chloroform solution without being particular about the color.

Therefore, the oil-and-sand layers are appropriately sampled and collected, and the sediment samples at the respective sampling positions are uniformly mixed, and the oil content of each of the mixed sediment samples is quantified to obtain the mixed sediments having different oil contents. Each of the chloroform solutions prepared by dissolving a certain amount of the sample in a certain amount of a chloroform solution having a constant concentration is used as a colorimetric sample sample. Then, the lightness of the color of each colorimetric sample sample is set as the oil content of the colorimetric sample sample. Then, a chloroform solution obtained by dissolving a certain amount of the earth and sand sample arbitrarily collected from the oil-containing earth and sand band in the constant amount of the chloroform solution of the constant concentration is used as the investigation sample. Next, comparing the lightness of the coloration of the investigation sample and the lightness of the coloration of the colorimetric sample, if the lightness of the former matches the lightness of either of the latter, the lightness of the latter matches.
The oil content of the colorimetric sample is judged to be the former oil content. When the former lightness is an intermediate lightness of the latter two types, the former oil content is determined from the proportional relationship between the lightness and the oil content drop of the two colorimetric sample samples. To do.

If the difference in the oil content of the chloroform solution with various oil contents is not clear as the difference in the lightness of the color, increase the chloroform dilution of the colorimetric sample sample and the investigation sample to the same degree as appropriate. By
The difference in lightness of the color can be made clear. In addition, the difference in lightness of color of the chloroform solution can be color-recognized when the oil content is up to about 20%. Therefore, if you prepare 5%, 10%, and 15% of oil concentration as a sample for concentration comparison of chloroform solution, the lightness of the coloration showing the oil content of the investigation sample will be The lightness of the sample can be efficiently compared visually and the oil content of the investigated sample can be easily known.

Chloroform dissolves a wide range of organic compounds such as fats, mineral oils, waxes, alkaloids, resins, rubbers and tars as described above, and is hardly soluble in silicic acid which is the main component of earth and sand. The degree of color of the chloroform solution, which is colored by reacting with, exhibits a high degree of correlation with the oil content calculated using the n-hexane extraction method. Therefore, if the coloration of chloroform in a sample with a known oil content is prepared in advance as a color sample, by comparing the color sample with the coloration of chloroform obtained from a sample with an unknown oil content, the oil content can be increased. You can know.
It should be noted that it is preferable to use a dry sample as a sample for making an n-hexane solution and a sample for making a chloroform solution in order to reduce errors in oil content and coloration due to water content, volatile content, and the like.

A conventional method for colorimetric determination of chloroform solution is a chloroform solution obtained by extracting a chloroform solution in which only oil is dissolved from a sample to be measured for oil content, and measuring the color of the extracted solution using a spectrophotometer. The oil content is determined by comparing the permeation rate of the sample at a predetermined wavelength in the solution, or the conversion value based on this, such as the chromaticity coordinate, or the converted value such as the stimulation value, with those with a known oil content. To do. The above-mentioned work of displaying the permeation rate, chromaticity coordinates, stimulus value, etc. is minute and cumbersome, and thus is not suitable as a quantitative method to be carried out at the site of reforming oil-containing soil.

However, the simple method for measuring the oil content in the oil-containing soil according to the present invention is different from the conventional quantification method using a spectrophotometer from the extracted chloroform solution in which the substance to be measured is dissolved, as described above. , The chloroform solution is not the extracted one, but the oil-bearing earth and sand sample is directly dissolved, and about the chloroform solution in which impurities as well as oil are still dissolved, with a color that looks natural in natural light,
It is extremely simple because it measures the oil content,
It cannot be easily achieved by the conventional quantification method. Since the chloroform solution having a known oil content was made from the mixed sediment sample whose oil content was quantified using the n-hexane extraction method, a chloroform solution prepared from another sample having the same oil content was presented. The color is similar to that of a chloroform solution having a known oil content and dissolved at the same rate, and thus the color is similar, and these colors are similar in color and brightness. Further, even if the oil content is different, since the oil species and the amounts of impurities constituting the oil content are the same, they have the same color and different lightness.

Although the coloration of the chloroform solution is slightly different depending on the ratio of the constituent oil of the oil species and impurities impregnated in the oil-containing soil, both the colorimetric sample sample and the survey sample are collected from the same oil-containing soil band. Therefore, these samples show the same color according to the ratio of the constituent oils of the oil-containing earth and sand band. Therefore, the oil content can be determined as described above by comparing the lightness in the same color. Conventionally, it took about 6 hours to calibrate the oil content of one sample, but according to the method for calibrating the oil content of the present invention, that is, the method for measuring the oil content by coloring a chloroform solution, It has become possible to perform the test in about 10 minutes per sample.

[0015]

EXAMPLES Next, examples embodying the present invention will be described to provide an understanding of the present invention. First, in the first step, a chloroform solution of oil-containing earth and sand having a known oil content is prepared. Samples for quantitative determination of oil content are collected from the oil-containing soil and each sample is uniformly mixed. The n-hexane extraction method according to JIS K0102 is used to quantify the oil content for each oil content determination sample. Each of the above-mentioned various mixed samples for quantitative determination of oil content is oven-dried. Collect 2 g of each sample in a beaker. Chloroform (99% concentration) 20-25 cc is added to each of the beakers. Shake each beaker for about 2 minutes to elute the oil. Filter the solution from each beaker into a test tube. Dilute each filtered solution to 30 cc with chloroform and store in a 15 ml screw tube. The luminosity of the stored various chloroform solutions is used as the calibration color.

In the next second step, a chloroform solution prepared by dissolving oil-containing earth and sand having an unknown oil content is prepared. A sample is collected from the oil-impregnated soil from the target site for oil content measurement. Oven dry the sample. A 2 g sample is collected in a beaker. Chloroform (99% concentration) 20-25 cc is added to the beaker. Shake for about 2 minutes to elute the oil. The beaker solution is filtered into a test tube. The filtered solution is diluted with chloroform to 30 cc.

In the third step, the oil content is determined by comparing the chloroform solution of the known oil content produced in the first step with the lightness of the color of the chloroform solution prepared in the second step.

[0018]

INDUSTRIAL APPLICABILITY In the modification work of oil-containing earth and sand by adding the oil-containing hardening material, it is possible to know the oil content of the oil-containing earth and sand excavated every time it is dug up in about 10 minutes. Therefore, while excavating the oil-bearing soil band, the necessary amount of the oil-bearing hardener to be added to the excavated soil can be calculated in about 10 minutes, so that the soil modification work described above can be progressed efficiently. It became so. Furthermore, since neither excessive addition of oil-impregnated hardener nor addition shortage is eliminated, economical and high-quality soil reforming work can be performed. Therefore, as described above, the present invention greatly contributes to the prevention of the expansion of soil-contaminated area by oil.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayoshi Yokoo, No. 1-1 Tobata-cho, Tobata-ku, Kitakyushu, Kitakyushu, Fukuoka Prefecture (72) Inside the Yawata Works, Nippon Steel Co., Ltd. (72) Kaigo Shimizu, Tobata-ku, Kitakyushu, Fukuoka No. 1 Tobatacho Shin Nippon Steel Co., Ltd., Yawata Works (72) Inventor Takehiko Takasaki 9-27 Kawabuchi-cho, Yawatahigashi-ku, Kitakyushu, Fukuoka Prefecture Taihei Kogyo Co., Ltd. Yawata Branch (72) Inventor Chiharu Nishi 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Okumura-gumi Co., Ltd. (72) Inventor Yoshito Kumagai 2--2, Matsuzaki-cho, Abeno-ku, Osaka-shi, Osaka City Okumura-gumi Co., Ltd.

Claims (1)

[Claims] 1. Sediment samples are appropriately sampled and collected from a plurality of locations in the oil-bearing sediment band, and the oil content of the sediment sample at each sampling position is quantified. From the quantified sediment samples, sediment samples with different oil content are selected. Each of the lightness of the color of a chloroform solution obtained by selecting a plurality of the selected sediment samples (A) and dissolving them in a certain amount (C) of a chloroform solution having a constant concentration (B), and the oil-containing sediment band By comparing a certain amount (A) of a sediment sample arbitrarily collected from the above with the lightness of the color of a chloroform solution prepared by dissolving it in a certain amount (C) of the chloroform solution having the constant concentration (B), A simple method for measuring the oil content of oil-containing soil, which comprises determining the oil content of an arbitrarily collected soil sample.