Method for quickly confirming damage degree of soil oil spill pollution environment

Abstract

The invention discloses a method for quickly confirming the damage degree of a soil oil spill pollution environment. The method comprises the following steps: 1) determining a target detection area, and selecting a predetermined number of detection points in the target detection area; 2) for each sample, detecting the petroleum hydrocarbon in the sample, fitting a depth-content curve based on the content of the petroleum hydrocarbon measured at a plurality of depths on each sampling point, and integrating the area of the depth-content curve of each sampling point to obtain a depth-content curve; dividing the integral result by the total sampling amount at the plurality of sampling depths to obtain the average content of the petroleum hydrocarbon at the sampling point, and calculating the comprehensive average content of all the detection areas. According to the method, the oil spill quantity in the area can be evaluated, and the damage degree is directly determined by the oil spill quantity.

Description

Technical Field

[0001] The invention relates to the field of extraction and detection of petroleum hydrocarbons, and in particular to a method for quickly confirming the degree of environmental damage caused by soil oil spill pollution. Background Art

[0002] Petroleum is mainly composed of petroleum hydrocarbons (saturated hydrocarbons, aromatic hydrocarbons, asphalt and colloid) and heavy metals. It is a dark brown or black viscous liquid, an important resource for human survival and development. As an indispensable energy source in today's world, it is called "the blood of modern industry" and "black gold". It is widely used in all walks of life. As a pillar industry of the country, the petroleum industry plays an important role in promoting economic development.

[0003] With the rapid development of the industrialization process of human society, the demand for petroleum products is increasing day by day. People are constantly increasing the exploration and exploitation of oil and gas resources. The demand for crude oil and its products is increasing day by day. During the exploitation, production, transportation, storage and processing, oil is accidentally leaked into the soil, causing serious harm to the ecological environment. In this process, a series of problems such as oil leakage will occur. After petroleum substances enter the soil, they will cause serious environmental pollution problems, especially in the oil fields of various countries.

[0004] The basis of oil spill pollution assessment is to accurately measure the extent of oil spills and the area, scope and soil depth of oil spill pollution, so as to further evaluate its impact on environmental damage. It can be seen that the determination of oil concentration in oil spill environments, especially in contaminated soil environments, is of great significance.

[0005] The determination of soil petroleum concentration can directly reflect the content of petroleum hydrocarbon pollutants in the soil and is a key indicator for assessing the degree of soil pollution. By measuring the content of petroleum hydrocarbons in the soil, it is possible to determine whether the soil is polluted and the severity of the pollution.

[0006] The determination of soil oil concentration helps determine the scope and extent of environmental pollution damage. By comparing soil oil concentrations at different points, we can understand the distribution of pollutants and thus assess the geographical scope and depth of pollution.

[0007] The results of the determination of soil petroleum concentration are crucial for formulating soil remediation plans. According to the concentration and type of petroleum hydrocarbons in the soil, appropriate remediation technologies, such as ex situ thermal desorption technology, can be selected to ensure the effectiveness and efficiency of remediation. The determination of soil petroleum concentration is the basis for risk assessment. Petroleum hydrocarbon pollutants may pose risks to human health and ecosystems. By measuring soil petroleum concentration, these risks can be assessed and corresponding prevention and control measures can be taken.

[0008] The determination of soil petroleum concentration is also an important part of environmental science research. By studying the changes in soil petroleum concentration, we can better understand the environmental behavior of pollutants and provide a scientific basis for the prevention and control of environmental pollution.

[0009] Petroleum hydrocarbons have high carbon content, many types of organic matter, and are difficult to degrade. When they enter the soil, they will adhere to the surface of soil particles to form a mucous film, affecting soil permeability, causing a decrease in soil fertility, and reducing the content of effective phosphorus and nitrogen in the soil, affecting the growth and metabolism of indigenous soil microorganisms, destroying the structure of the biological community in the soil, and further deteriorating the natural ecological environment of the soil. As a difficult-to-degrade complex organic matter, petroleum hydrocarbons will not only change the structure of soil microbial communities and soil nutrient composition, but also affect its permeability by adhering to soil particles, thereby hindering the respiration of crop roots and even causing crop death. Petroleum pollution will seriously affect the use function of land, causing changes in soil structure and properties, changes in microbial community structure, and reduced soil enzyme activity, and will lead to environmental problems such as vegetation ecological damage, disordered crop metabolic processes, and water pollution. After entering the soil, petroleum will penetrate and erode the soil layer, causing changes in soil structure. The probability of salinization, asphaltization, and compaction of polluted soil will increase significantly. Petroleum pollutants have a certain degree of hydrophobicity, which will cause soil particles to stick together and block soil pores, thereby affecting the soil's ventilation and water permeability. Oil pollution causes a significant decrease in soil moisture content. Insufficient soil water holding and water supply capacity is extremely detrimental to crop growth. It can also cause a serious imbalance in the soil carbon-nitrogen ratio, affect the growth and reproduction of microorganisms, and destroy the soil microecological environment. After the soil is contaminated by oil, its microbial community structure and diversity will be affected to varying degrees. Oil pollution has varying degrees of inhibitory effects on the activities of three hydrolases (sucrase, urease and alkaline phosphatase) related to soil carbon, nitrogen and phosphorus conversion. Generally, soil enzyme activity tends to decrease with the deepening of oil pollution. After oil pollutants enter the soil, they will also form a mucous film on the surface of plant roots, affecting root respiration and root absorption of nutrients and water. When the pollution is more serious, it will cause plant root rot, thereby affecting crop yields. Oil wastewater may also penetrate deep into the soil and even pollute shallow groundwater. Petroleum hydrocarbons in the soil ecosystem can cause lasting or potential harm to human health and environmental receptors through ecological cycles and food chains. Petroleum hydrocarbons in the soil can enter animals and humans through ecological cycles and food chains, thus causing potential or lasting harm to human health. Therefore, paying attention to the petroleum pollution of soil in oilfield areas is an important part of soil pollution prevention and control.

[0010] The components of petroleum hydrocarbons are very complex, and the toxicity of different components varies greatly. Therefore, using appropriate methods to determine the total amount and content of each component of petroleum pollutants in soil is a prerequisite for accurately evaluating the degree of soil pollution and its biological toxicity. In terms of the determination standards of petroleum and related substances in soil, my country has not yet established a complete soil total petroleum hydrocarbon (TPH) detection method system. Commonly used soil TPH analysis methods include gravimetric method, infrared spectroscopy (IR), ultraviolet spectrophotometry (UV), gas chromatography (GC-FID), gas chromatography-mass spectrometry (GC-MS), immunoassay (IMA), Raman spectroscopy, nuclear magnetic resonance (NMR) and fluorescence spectroscopy. In environmental site investigation and remediation, the most widely used and rapid measurement methods include gravimetric method, IR, UV and GC-FID.

[0011] The ultraviolet method is based on the determination of polycyclic aromatic hydrocarbons containing a large number of conjugated double bonds as the main toxicity in petroleum hydrocarbons, and expresses the petroleum hydrocarbon content through the characteristic absorption caused by the conjugated double bond structure contained in petroleum hydrocarbons. Although this method has high sensitivity, the spectral characteristics caused by the composition and structure of hydrocarbons in different samples are also very different, resulting in poor anti-interference ability. It is necessary to set up a preliminary experiment with the crude oil sample to be tested as a reference oil, and then conduct the detection experiment after determining the optimal absorption wavelength and drawing a standard curve. The infrared spectroscopy method uses an extraction agent such as carbon tetrachloride or tetrachloroethylene to extract petroleum compounds from the sample, and then uses magnesium silicate or silica gel to remove the polar components, and then uses the three-wavelength method, that is, -CH3, -CH2-, =CH- at 2960, 2930, 3030cm -1 Based on the existence of CH bond stretching vibration at wavelength, qualitative and quantitative analysis is performed to determine the total petroleum hydrocarbon content. This method can detect alkanes, cycloalkanes and most aromatic compounds, and has reliability and integrity. However, since the extraction solvents used are usually highly toxic and will produce chlorofluorocarbons, leading to the greenhouse effect, a more environmentally friendly alternative solvent, tetrachloroethylene, has been found. However, it is difficult to promote due to its high price and low purity, which limits the development of infrared methods to a certain extent. The weight method is to first use volatile solvents such as petroleum ether to extract petroleum hydrocarbons in the soil, then pour the extract into a small beaker or other container, place it in a fume hood to evaporate and remove the solvent, and then weigh and calculate the mass of the residual substance in the container, which is the TPH content in the soil. This method has the lowest requirements for instrument conditions, but because heavy hydrocarbons in crude oil may not be completely extracted, and some light petroleum hydrocarbon components may also evaporate during the solvent volatilization process, thus introducing measurement errors. At the same time, it has low sensitivity and is relatively time-consuming, which limits its scope of application.

[0012] Inappropriate determination methods will lead to significantly different determination results. The final determination results will also be affected by factors such as the test standards and the extraction reagents used. In addition, the determination requirements of petroleum hydrocarbon substances in different industries are also different for each detection method. There is no single method that can accurately measure the true petroleum hydrocarbon concentration of all types of pollution. Each method has its own advantages and disadvantages. When selecting a determination method, factors such as determination time, determination cost, operation difficulty, and accuracy requirements of the test results should be fully considered. The existing ultraviolet method determination in the prior art has the defects of low determination accuracy, complex operation, and a single applicable soil type.

[0013] Therefore, it is crucial to establish an accurate method for determining total petroleum hydrocarbons or normal alkanes (C10-C40) in soil. Accurate determination of oil spill pollution in soil is also the basis for assessing ecological environmental damage caused by oil spill pollution. Summary of the invention

[0014] The invention aims at the problems in the prior art in the method for determining the degree of ecological environmental damage caused by oil spill pollution, and provides a method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil.

[0015] The present invention aims at the problem that the ecological environment damage assessment method of oil spill pollution is insufficient in the prior art, and provides an ecological environment damage assessment method for oil spill pollution.

[0016] Preferably, the ecological environmental damage assessment method includes the step of detecting petroleum hydrocarbons in the soil.

[0017] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention can accurately assess the degree of pollution caused by the oil spill accident to the environment, which is crucial for understanding the severity and scope of the accident. The measurement results of oil concentration can provide a scientific basis for emergency response and help formulate effective emergency measures to reduce the damage of the oil spill to the environment and ecosystem.

[0018] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0019] The present invention discloses a method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil, the method comprising:

[0020] 1) determining a target detection area, selecting a predetermined number of detection points in the target detection area, and performing sampling detection at multiple depths for each detection point;

[0021] 2) For each sample, the petroleum hydrocarbons in the soil are tested. The testing process includes:

[0022] 2.1) Take a predetermined amount (e.g., 50 g, 10 g, 5 g, 2 g, 1 g) of the soil to be tested and a desiccant in a conical flask, add an extractant, shake and mix, perform ultrasonic extraction, and collect the supernatant by centrifugation. The extractant is a mixture of carbon tetrachloride, hexane, and trichlorotrifluoroethane or a mixture of carbon tetrachloride, pentane, and petroleum ether;

[0023] 2.2) Repeat step 1, and combine the supernatants from the two extractions and concentrate the volume to 1-2 mL;

[0024] 2.3) The concentrate was passed through a magnesium silicate purification column, the eluate was collected and concentrated to 1 mL for later use;

[0025] 2.4) taking the concentrated solution in step 3) and testing it in a cuvette, and calculating the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve;

[0026] 3) fitting a depth-content curve based on the petroleum hydrocarbon contents measured at multiple depths at each sampling point;

[0027] 4) Integrate the area of ​​the depth-content curve at each sampling depth, and divide the integral result by the total sampling amount at multiple sampling depths to obtain the average content of petroleum hydrocarbons at the sampling point;

[0028] 5) For all sampling points, the comprehensive average content of all detection areas is calculated based on the average content of petroleum hydrocarbons at each sampling point, and the ecological environmental damage is evaluated based on the comprehensive average content of all detection areas.

[0029] Preferably, the detection points are evenly distributed, and each detection point covers the same area. For example, a square area centered on each detection point is used as the coverage area of ​​the detection point.

[0030] Preferably, in step 5), the inflection point of the petroleum hydrocarbon concentration at each sampling point is determined, the average slope between the sampling points after the inflection point is calculated, and the contamination depth is determined based on the average slope.

[0031] Preferably, in step 2.1), the mass ratio of the soil to the desiccant is 2:1, the desiccant is magnesium sulfate, and the soil includes red soil, brown soil and black soil.

[0032] Preferably, the mass ratio of the soil to the desiccant in step 2.1) is (1-2): (0.5-1).

[0033] Preferably, in step 2.1), the mass volume ratio of the soil to the extractant is (1-2) g: (5-10) mL.

[0034] Preferably, in step 2.1), the mass volume ratio of the soil to the extractant is 1 g:5 mL.

[0035] Preferably, the mass volume ratio of the soil, the desiccant and the extractant in step 2.1) is 1g:2g:5mL. Preferably, step 5 also includes: summarizing the petroleum hydrocarbon content per unit volume at each detection point, taking the intersection of the depth-content curve at each sampling point and the horizontal axis 0 point as the pollution depth, calculating the total volume of the polluted area covered by each sampling point, calculating the total petroleum hydrocarbon content of the area based on the total volume of the polluted area and the average concentration of petroleum hydrocarbons at the sampling point, and evaluating the ecological environmental damage based on the total petroleum hydrocarbon content of the covered area.

[0036] Preferably, the carbon tetrachloride, hexane and trichlorotrifluoroethane are prepared in a volume ratio of 1:1:1, and the carbon tetrachloride, pentane and petroleum ether are prepared in a volume ratio of 1:1:1.

[0037] Preferably, the eluent in step 3) is n-hexane.

[0038] Preferably, the detection wavelength in step 4) is 254 nm.

[0039] Preferably, the method further comprises evaluating ecological environmental damage based on the calculated petroleum hydrocarbon concentration in the soil.

[0040] The present invention also provides a method for detecting the concentration of oil spill in oil-contaminated soil, the method comprising the above steps 1)-4).

[0041] The invention provides an extractant for extracting petroleum hydrocarbons in soil.

[0042] The extractant includes: carbon tetrachloride, hexane, trichlorotrifluoroethane or carbon tetrachloride, pentane, petroleum ether or pentane, cyclohexane, and chloroform.

[0043] The present invention discloses a method for assessing ecological environmental damage caused by oil spill pollution. The method comprises the steps of detecting petroleum hydrocarbons in soil, including:

[0044] 1) Put the soil to be tested and the desiccant into a conical flask, add the extractant, shake and mix, perform ultrasonic extraction, and collect the supernatant by centrifugation. The extractant is a mixture of carbon tetrachloride, hexane, and trichlorotrifluoroethane or a mixture of carbon tetrachloride, pentane, and petroleum ether;

[0045] 2) Repeat step 1, combine the supernatants from the two extractions, and concentrate the volume to 1-2 mL;

[0046] 3) The concentrated solution was passed through a magnesium silicate purification column, and the eluate was collected and concentrated to 1 mL for later use;

[0047] 4) The concentrated solution in step 3) is tested in a cuvette, and the concentration of petroleum hydrocarbons in the soil is calculated using a petroleum hydrocarbon standard curve.

[0048] Preferably, the mass ratio of the soil to the desiccant in step 1) is 2:1.

[0049] Preferably, the desiccant is magnesium sulfate.

[0050] Preferably, the soil includes red soil, brown soil and black soil.

[0051] Preferably, the petroleum hydrocarbon is C10-C40 petroleum hydrocarbon.

[0052] Preferably, the carbon tetrachloride, hexane and trichlorotrifluoroethane are prepared in a volume ratio of 1:1:1.

[0053] Preferably, the carbon tetrachloride, pentane and petroleum ether are prepared in a volume ratio of 1:1:1.

[0054] Preferably, the eluent in step 3) is n-hexane.

[0055] Preferably, the detection wavelength in step 4) is 254 nm.

[0056] Preferably, the method further comprises evaluating ecological environmental damage based on the calculated petroleum hydrocarbon concentration in the soil.

[0057] The purpose of the present invention is to provide a method for extracting and detecting petroleum hydrocarbons in soil in order to solve the problem that the detection methods for petroleum hydrocarbons in contaminated soil in the prior art are insufficient and have low accuracy.

[0058] The present invention screened and obtained an extractant suitable for extracting petroleum hydrocarbons from various soil types. The standard curve of the petroleum standard concentration solution established using the extractant of the present invention has a high R 2 The extractant of the present invention can be used to efficiently extract petroleum hydrocarbons from various types of soil, including red soil, brown soil and black soil. The method of the present invention can accurately measure the petroleum hydrocarbon pollution in different types of soil, and the detection repeatability is good. According to the method disclosed in the present invention, the detection of petroleum hydrocarbons in soil can be further used to evaluate the ecological environment damage based on the measured petroleum hydrocarbon concentration in the soil.

[0059] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed in the present invention can be effectively applied to a variety of different occasions, including: judging whether the soil is polluted and the severity of the pollution, determining the scope and degree of environmental pollution damage, formulating soil remediation plans, ensuring the effect and efficiency of soil remediation, and through regular measurements, better understanding of the spread of pollutants and better prevention and control of environmental pollution can be achieved.

[0060] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention is an indispensable part of oil spill assessment, and provides important data support for accident response, environmental restoration, legal proceedings and scientific research.

[0061] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention is crucial for formulating environmental restoration plans, and can ensure that the restoration measures taken are highly targeted and effectively restore the damaged environment.

[0062] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention can be used to evaluate environmental damage, which is also the key to determining the liability and amount of compensation. The determination of oil content provides a quantitative basis for damage compensation.

[0063] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention is an important part of environmental science research and helps to better understand the environmental behavior and ecological impact of oil spill pollution.

[0064] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention helps to evaluate pollution trends and prevent future oil spill accidents by regularly monitoring the oil concentration in the environment.

[0065] The method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil disclosed by the present invention can provide the public with accurate information on the petroleum hydrocarbon content in the environment caused by the oil spill, thereby increasing the public's awareness and concern about environmental issues and promoting the improvement of environmental protection awareness. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic flow chart of the method of the present invention.

[0067] Figure 2 Standard curve plot established for the first set of extractants.

[0068] Figure 3 Standard curve plot established for the second set of extractants.

[0069] Figure 4 Standard curve plot established for the third set of extractants. DETAILED DESCRIPTION

[0070] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0071] like Figure 1 As shown, in an embodiment of the present invention, a method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil comprises the following steps:

[0072] 1) determining a target detection area, selecting a predetermined number of detection points in the target detection area, and performing sampling detection at multiple depths for each detection point;

[0073] Since it is impossible to exhaustively sample during the oil spill detection process, it is necessary to divide the oil spill area. The specific division granularity is mainly determined based on the detection accuracy. Preferably, each detection point is evenly distributed, and each detection point covers the same area. For example, the square area centered on each detection point is used as the coverage area of ​​the detection point. The detection area can be divided into squares of a certain length (for example, 5 meters, 10 meters, 30, 50, 100, 1000 meters), and a sampling point is selected at the center of each square. The sampling point is sampled at different depths according to the degree of pollution.

[0074] 2) For each sample, the petroleum hydrocarbons in the soil are tested. The testing process includes:

[0075] 2.1) taking a predetermined amount of soil to be tested and a desiccant into a conical flask, adding an extractant, shaking and mixing, ultrasonic extraction, and centrifuging to collect the supernatant, wherein the extractant is a mixture of carbon tetrachloride, hexane, and trichlorotrifluoroethane or a mixture of carbon tetrachloride, pentane, and petroleum ether;

[0076] 2.2) Repeat step 1, and combine the supernatants from the two extractions and concentrate the volume to 1-2 mL;

[0077] 2.3) The concentrate was passed through a magnesium silicate purification column, the eluate was collected and concentrated to 1 mL for later use;

[0078] 2.4) taking the concentrated solution in step 3) and testing it in a cuvette, and calculating the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve;

[0079] 3) fitting a depth-content curve based on the petroleum hydrocarbon contents measured at multiple depths at each sampling point; preferably, the number of sampling points exceeds 3, and the fitting can be performed using the least squares method, and a downward-opening parabola can be used as a basic curve to fit the curve.

[0080] 4) For each sampling point, the area of ​​the depth-content (depth as the horizontal axis - content as the vertical axis) curve is integrated, and the integration result is divided by the total sampling amount (measured sample amount) at multiple sampling depths to obtain the average content of petroleum hydrocarbons at the sampling point; in one implementation, the following formula is used to calculate the amount of petroleum hydrocarbons at any sampling point: H represents the total depth of oil-bearing soil, and C(h) is the petroleum hydrocarbon content per unit mass of soil at the depth h in the fitting curve.

[0081] 5) For all sampling points, the comprehensive average content of all detection areas is calculated based on the average content of petroleum hydrocarbons at each sampling point, and the ecological environmental damage is evaluated based on the comprehensive average content of all detection areas (because the areas covered by each sampling point are the same, the comprehensive average content represents the content per unit area of ​​the polluted area, and the pollution degree can be comprehensively evaluated in combination with the area of ​​the detection area). In one implementation, N is the number of sampling points, and Cn is the petroleum hydrocarbon content at the nth sampling point (the average content here refers to the average content per unit sampling mass).

[0082] Preferably, in step 5), the inflection point of the petroleum hydrocarbon content at each sampling point is determined, the average slope between the sampling points after the inflection point is calculated, and the contamination depth is determined based on the average slope.

[0083] Preferably, step 5 also includes: summarizing the petroleum hydrocarbon content per unit volume at each detection point, taking the intersection of the depth-content curve at each sampling point and the zero point of the horizontal axis as the pollution depth, calculating the total volume of the polluted area covered by each sampling point, calculating the total petroleum hydrocarbon content of the area based on the total volume of the polluted area and the average petroleum hydrocarbon content at the sampling point, and evaluating the ecological environmental damage based on the total petroleum hydrocarbon content of the covered area.

[0084] Another important difficulty of the present invention is the rapid and accurate determination of the petroleum hydrocarbon content. The following is a detailed description of the example of detection in step 2.

[0085] Example 1 Preliminary screening of extraction reagents

[0086] The rapid and sufficient extraction of petroleum hydrocarbons in the soil is the basis for the determination, and the linearity of the standard curve established by the extraction reagent is also an important factor in the accuracy of the determination. The type and polarity of the extractant will affect the extraction and dissolution of petroleum hydrocarbons in the soil, and will further affect the absorption value of the subsequent UV determination. A good extractant should be able to fully dissolve the petroleum hydrocarbons in the extracted soil, and the stability of the UV absorption determination of the product after dissolving different concentrations of petroleum hydrocarbons should also reflect the minimum error range.

[0087] The present application randomly selects three kinds of extractants from common petroleum hydrocarbon extractants according to the differences in polarity and non-polarity and divides them into one group. The extractants in each group are prepared according to a volume ratio of 1:1:1, and a total of three groups of different extractants are obtained. The specific formulas are shown in Table 1.

[0088] Table 1: Formulas of different extractants

[0089]

[0090] Example 2: Standard curves established with different extraction reagents

[0091] 1) Preparation of different extraction agent standard concentration solutions:

[0092] C10-C40 standard crude oil was dissolved in different groups of extractants in Example 1, with an initial concentration of 200 mg / L, and further diluted with each group of extractants to a concentration gradient of 0, 1 mg / L, 2 mg / L, 4 mg / L, 8 mg / L and 16 mg / L;

[0093] 2) Determination of ultraviolet luminescence value of standard concentration solution. For each determination, about 0.3 mL of the standard solution was taken into a cuvette for testing. The wavelength of the determination was 254 nm. The control was an extractant without standard crude oil. The determination of each concentration of standard solution was repeated three times. The determination results of different concentrations of standard solutions of the first to third groups of extractants are shown in Tables 2 to 4 respectively.

[0094] Table 2: UV values ​​of the first set of extractant standard solutions

[0095]

[0096]

[0097] Table 3: UV values ​​of the second set of extractant standard solutions

[0098] Group 1mg / L 2mg / L 4mg / L 8mg / L 16mg / L First absorbance measurement 0.028 0.055 0.136 0.311 0.626 Second absorbance measurement 0.035 0.061 0.155 0.278 0.516 The third absorbance measurement 0.031 0.054 0.143 0.269 0.597 average value 0.031 0.057 0.145 0.286 0.613

[0099] Table 4: UV measurement values ​​of the third group of extractant standard solutions

[0100] Group 1mg / L 2mg / L 4mg / L 8mg / L 16mg / L First absorbance measurement 0.033 0.077 0.128 0.263 0.646 Second absorbance measurement 0.026 0.074 0.135 0.293 0.592 The third absorbance measurement 0.043 0.082 0.154 0.258 0.567 average value 0.034 0.078 0.139 0.271 0.602

[0101] 3) Establishment of crude oil standard curve: Draw the standard curve with the average absorbance of each group as the ordinate and the concentration of crude oil standard solution as the abscissa, obtain the corresponding standard curve equation, and calculate the correlation coefficient R of the standard curve corresponding to each extraction agent 2 The results are as follows Figure 2-Figure 4 shown.

[0102] From the obtained results, the linear results of the first group of extractants are the best, R 2 The value is 0.9996, indicating that after dissolving crude oils of various concentrations as an extractant, the UV absorbance value is less affected, and it performs best among the three extractants provided.

[0103] Example 3 Effect of extraction reagents on the extraction of petroleum contamination in different types of soil

[0104] 2.1 Selection of test soil

[0105] Three different types of uncontaminated soil were selected, including red soil, brown soil and black soil. Among them, red soil was collected from a city in Jiangxi Province, brown soil was collected from a city in Shanxi Province, and black soil was collected from a city in Heilongjiang Province. In order to ensure that the properties of the tested soils are as consistent as possible, the soil sampling depth was about 150 cm from the surface, and the five-point sampling method was used for soil collection.

[0106] 2.2 Treatment of test soil

[0107] The collected soil was transported back to the laboratory to remove possible stones, debris and other impurities, placed in a freeze-drying apparatus to remove moisture, sieved through a 2 mm sieve, and naturally air-dried before grinding for later use.

[0108] 2.3 Establishment of soil pollution model

[0109] C10-C40 standard crude oil was dissolved in petroleum ether (boiling point 30-60°C) at a mass-to-volume ratio of 1:10, and added to the above-mentioned different types of soil at a mass ratio of (0.2 mg:100) g, i.e., 0.2 mg of C10-C40 standard crude oil was added to 100 g of soil. The soil was fully stirred and the treated contaminated soil sample was placed in a fume hood for 2-4 hours, during which the soil was properly turned over to obtain the contaminated soil after the petroleum ether evaporated.

[0110] 2.4 Extraction and determination of petroleum hydrocarbons in contaminated soil

[0111] 1) Accurately take 2 grams of each type of contaminated soil (red soil, brown soil and black soil) and 1 gram of desiccant anhydrous magnesium sulfate into a conical flask, and perform 3 parallel measurements for each soil;

[0112] 2) Add 10 mL of the first group of extractants (carbon tetrachloride: cyclohexane: trichlorotrifluoroethane in a volume ratio of 1:1:1), shake and mix, and extract by ultrasonic treatment for 5-10 minutes; centrifuge and collect the supernatant;

[0113] 3) Add 5 mL of the first group of extractants to the centrifugal precipitate, shake and mix, and then extract by ultrasonic treatment for 5-10 minutes; centrifuge and collect the supernatant;

[0114] 4) combining the supernatants collected in step 2) and step 3), and concentrating the supernatants to a volume of 1 mL using a concentrator;

[0115] 5) The concentrated solution obtained in step 4) was passed through a magnesium silicate purification column, and the column was eluted with n-hexane. The eluate was collected and concentrated to 1 mL for later use.

[0116] 6) Take 0.3 mL of the concentrated solution prepared in step 5) and put it in a cuvette for testing. The wavelength is 254 nm. After the corresponding OD value is measured, the average value is calculated. The concentration of petroleum hydrocarbons in the soil is further calculated using the established standard curve. The measurement and calculation results are shown in Table 5 below.

[0117] Table 5: Test and calculation results of different soils

[0118] Group Red soil Brown soil Black soil The first group of OD values 0.073 0.066 0.071 The first group of OD values 0.062 0.064 0.068 The first group of OD values 0.065 0.062 0.064 Average OD value 0.067 0.062 0.068 Concentration of petroleum hydrocarbons (C10-C40) in soil (mg / kg) 1.86 1.72 1.89

[0119] From the test results, it can be seen that the first extractant can effectively extract petroleum hydrocarbons from three different types of soil.

[0120] Example 4 Repeatability determination of extraction reagents

[0121] 1) A piece of uncontaminated soil of unknown type was randomly selected for repeatability determination of the extractant. The soil was collected from the suburbs of Tianjin, the sampling depth of the soil was about 150 cm from the surface, and the five-point sampling method was used for soil collection.

[0122] 2) After the collected soil is transported back to the laboratory, possible stones, debris and other debris are removed, and it is placed in a freeze-drying instrument to remove moisture. After passing through a 2mm sieve, it is naturally air-dried and ground for later use.

[0123] 3) C10-C40 standard crude oil was dissolved in petroleum ether (boiling point 30-60°C) at a mass-volume ratio of 1:10, and added to the above soil at a mass ratio of (0.4 mg:100 g and 0.8 mg:100 g), i.e., 0.4 mg and 0.8 mg of C10-C40 standard crude oil were added to 100 g of soil, and the treated contaminated soil sample was placed in a fume hood for 2-4 hours, during which the soil was appropriately turned over to obtain the contaminated soil after the petroleum ether evaporated.

[0124] 4) Accurately take 2 grams of the prepared contaminated soil and 1 gram of the desiccant anhydrous magnesium sulfate into a conical flask, and perform 15 parallel measurements for each soil;

[0125] 5) Add 10 mL of the first group of extractants (carbon tetrachloride: cyclohexane: trichlorotrifluoroethane in a volume ratio of 1:1:1), shake and mix, and extract by ultrasonic treatment for 5-10 minutes; centrifuge and collect the supernatant;

[0126] 6) Add 5 mL of the first group of extractants to the centrifugal precipitate, shake and mix, and then extract by ultrasonic treatment for 5-10 minutes; centrifuge and collect the supernatant;

[0127] 7) The supernatants collected in step 2) and step 3) were combined and concentrated to a volume of 1 mL using a concentrator;

[0128] 8) The concentrated solution obtained in step 4) was passed through a magnesium silicate purification column, and the column was eluted with n-hexane. The eluate was collected and concentrated to 1 mL for later use.

[0129] 9) Take 0.3 mL of the concentrated solution prepared in step 5) and put it in a cuvette for testing. The wavelength is 254 nm. After the corresponding OD value is measured, the average value is calculated. The established standard curve is used to further calculate the content of petroleum hydrocarbons in the soil. The measurement and calculation results are shown in Tables 6 and 7 below.

[0130] Table 6: OD value results of repeatability test of extractant (0.4 mg / 100 g group)

[0131] 0.141 0.126 0.131 0.128 0.127 0.133 0.138 0.123 0.119 0.122 0.124 0.132 0.137 0.135 0.133

[0132] It was calculated that the standard deviation SD was 0.01 and the detection precision reached 4.96%, indicating good repeatability. The detection result was 3.58 mg / kg.

[0133] Table 7: OD value results of repeatability test of extractant (0.8 mg / 100 g group)

[0134] 0.272 0.265 0.280 0.263 0.267 0.259 0.255 0.258 0.261 0.266 0.262 0.275 0.268 0.264 0.251

[0135] It was calculated that the standard deviation SD was 0.01 and the detection precision reached 2.85%, indicating good repeatability. The detection result was 7.13 mg / kg.

[0136] The above results show that the extractant of the present invention can be used to effectively extract petroleum hydrocarbon contaminated soil of various concentrations, and the operation repeatability is good and the accuracy is high.

[0137] The present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for quickly confirming the degree of environmental damage caused by oil spill pollution in soil, characterized in that: The method comprises: 1) determining a target detection area, selecting a predetermined number of detection points in the target detection area, and performing sampling detection at multiple depths for each detection point; 2) For each sample, the petroleum hydrocarbons in the sample are tested. The testing process includes: 2.1) taking a predetermined amount of soil to be tested and a desiccant into a conical flask, adding an extractant, shaking and mixing, ultrasonic extraction, and centrifuging to collect the supernatant, wherein the extractant is a mixture of carbon tetrachloride, hexane, and trichlorotrifluoroethane or a mixture of carbon tetrachloride, pentane, and petroleum ether; 2.2) Repeat step 2.1), combine the supernatants from the two extractions, and concentrate the volume to 1-2 mL; 2.3) The concentrate was passed through a magnesium silicate purification column, the eluate was collected and concentrated to 1 mL for later use; 2.4) taking the concentrated solution in step 2.3) and testing it in a cuvette, and calculating the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve; 3) fitting a depth-content curve based on the petroleum hydrocarbon contents measured at multiple depths at each sampling point; 4) Integrate the area of ​​the depth-content curve of each sampling point, and divide the integral result by the total sampling amount at multiple sampling depths to obtain the average content of petroleum hydrocarbons at the sampling point; 5) For all sampling points, the comprehensive average content of all detection areas is calculated based on the average content of petroleum hydrocarbons at each sampling point, and the ecological environmental damage is evaluated based on the comprehensive average content of all detection areas.

2. The method according to claim 1, characterized in that The detection points are evenly distributed and each detection point covers the same area.

3. The method according to claim 1, characterized in that In the step 5), the inflection point of the petroleum hydrocarbon content at each sampling point with depth is determined, the average slope between the sampling points after the inflection point is calculated, and the contamination depth is determined based on the average slope.

4. The method according to claim 1, characterized in that: In step 2.1), the mass ratio of the soil to the desiccant is 2:1, the desiccant is magnesium sulfate, and the soil includes red soil, brown soil and black soil.

5. The method according to claim 1, characterized in that The petroleum hydrocarbon is C10-C40 petroleum hydrocarbon.

6. The method according to claim 1, characterized in that The step 5 also includes: summarizing the petroleum hydrocarbon content per unit volume at each detection point, taking the intersection of the depth-content curve at each sampling point and the horizontal axis 0 point as the pollution depth, calculating the total volume of the polluted area covered by each sampling point, calculating the total petroleum hydrocarbon content of the area based on the total volume of the polluted area and the average petroleum hydrocarbon content at the sampling point, and evaluating the ecological environmental damage based on the total petroleum hydrocarbon content of the covered area.

7. The method according to claim 1, characterized in that The carbon tetrachloride ring, hexane and trichlorotrifluoroethane are prepared in a volume ratio of 1:1:1, and the carbon tetrachloride, pentane and petroleum ether are prepared in a volume ratio of 1:1:

1.

8. The method according to claim 1, characterized in that The eluent in step 3) is n-hexane.

9. The method according to any one of claims 1 to 8, characterized in that: The detection wavelength in step 4) is 254 nm.

10. A method for detecting oil spill concentration in oil spill contaminated soil, characterized in that: The method comprises steps 1) to 4) of claim 1).

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