A method for quickly confirming the degree of environmental damage caused by soil oil spill pollution

Abstract

The present invention discloses a method for quickly confirming the degree of environmental damage caused by soil oil spill pollution. The method includes: 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 hydrocarbons in the sample, fitting a depth-content curve based on the contents of petroleum hydrocarbons measured at multiple depths at each sampling point, integrating the area of the depth-content curve of each sampling point, dividing the integration result by the total sampling amount at multiple sampling depths as the average content of petroleum hydrocarbons at this sampling point, and calculating the comprehensive average content of all detection areas. The method of the present invention can evaluate the amount of oil spill in the area, and the amount of oil spill directly determines the degree of damage.

Description

Technical Field

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

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

[0003] With the rapid development of the industrialization process of human society, the global demand for petroleum products has been increasing day by day. People have continuously increased the exploration and exploitation of oil and gas resources, and the demand for crude oil and its products has been increasing. During the processes of exploitation, production, transportation, storage and processing, petroleum is accidentally leaked into the soil, causing serious harm to the ecological environment. A series of problems such as oil spills will occur during this process. After petroleum substances enter the soil, it will cause serious environmental pollution problems, especially in the pollution situations of oil field areas in various countries are more prominent.

[0004] The basis for oil spill pollution assessment is to accurately measure the degree of oil spill, the area and scope of oil spill pollution, and the depth of the soil, etc., so as to further evaluate the magnitude of its impact on environmental damage. It can be seen that the determination of petroleum concentration in the oil spill environment, especially in the polluted soil environment, 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 evaluating the degree of soil pollution. By measuring the content of petroleum hydrocarbons in the soil, it can be judged whether the soil is polluted and the severity of the pollution.

[0006] The determination of soil petroleum concentration helps to determine the scope and degree of environmental pollution damage. By comparing the soil petroleum concentrations at different points, the distribution of pollutants can be understood, so as to evaluate the geographical scope and influence depth of the pollution.

[0007] The determination result of soil petroleum concentration is 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 remediation effect and efficiency. The determination of soil petroleum concentration is the basis for risk assessment. Petroleum hydrocarbon pollutants may pose risks to human health and the ecosystem. By measuring the soil petroleum concentration, these risks can be evaluated and corresponding preventive 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, the environmental behavior of pollutants can be better understood, providing a scientific basis for the prevention and control of environmental pollution.

[0009] Petroleum hydrocarbons are characterized by high carbon content, a large variety of organic substances, and are difficult to degrade. When they enter the soil, they will adhere to the surface of soil particles, forming a mucous membrane, which affects soil permeability, causes a decline in soil fertility, and also reduces the content of available phosphorus and nitrogen in the soil, affecting the growth and metabolism of indigenous soil microorganisms, damaging the soil biological community structure, and further deteriorating the soil natural ecological environment. As a kind of refractory composite organic matter, petroleum hydrocarbons not only change the soil microbial community structure and soil nutrient composition, but also affect its permeability by adhering to soil particles, thus hindering the root respiration of crops 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, a decrease in soil enzyme activity, and leading to environmental problems such as vegetation ecological damage, crop metabolic disorders, and water pollution. After petroleum enters the soil, it will penetrate and erode the soil layer, changing the soil structure, and significantly increasing the probability of salinization, bituminization, and hardening of the polluted soil. Petroleum pollutants have a certain hydrophobicity, which will cause soil particles to stick together, blocking soil pores, and then affecting the soil ventilation and water permeability. Petroleum pollution causes a significant decrease in the water content of the soil. The insufficient water holding and water supply capacity of the soil is extremely unfavorable to the growth of crops, and it will also cause a serious imbalance in the soil carbon-nitrogen ratio, affecting the growth and reproduction of microorganisms and damaging the soil microecological environment. After the soil is polluted by petroleum, its microbial community structure and diversity will be affected to varying degrees. Petroleum pollution has varying degrees of inhibitory effects on the activities of three hydrolytic enzymes (sucrase, urease, and alkaline phosphatase) related to soil carbon, nitrogen, and phosphorus transformation. Usually, the soil enzyme activity shows a downward trend with the deepening of petroleum pollution. After petroleum pollutants enter the soil, they will also form a mucous membrane on the surface of plant roots, affecting root respiration and the absorption of nutrients and water by roots. When the pollution is relatively severe, it will cause plant root rot, thus affecting crop yields. Petroleum wastewater may also penetrate deep into the soil and even pollute shallow groundwater. Petroleum hydrocarbons in the soil ecosystem can cause persistent or potential harm to human health and environmental receptors through ecological cycles and food chains. Petroleum hydrocarbons in the soil can enter animals and the human body through ecological cycles and food chains, thus causing potential or persistent harm to human health. Therefore, paying attention to the petroleum pollution situation in oilfield areas is an important part of soil pollution prevention and control work.

[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 component contents 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 for petroleum and related substances in soil, China has not yet established a complete detection method system for total petroleum hydrocarbons (TPH) in soil. Commonly used analytical methods for soil TPH include gravimetry, 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 field investigations and remediation, the most widely used and rapid measurement methods include gravimetry, IR, UV, and GC-FID.

[0011] The ultraviolet method is based on the main toxicity of polycyclic aromatic hydrocarbons containing a large number of conjugated double bonds in petroleum hydrocarbon substances, and expresses the petroleum hydrocarbon content through the characteristic absorption brought by the conjugated double bond structure contained in the petroleum hydrocarbon. Although this method has high sensitivity, due to the large differences in spectral characteristics caused by the composition and structure of hydrocarbons in different samples, its anti-interference ability is poor. It is necessary to set up a preliminary experiment with the crude oil sample to be measured as the reference oil, and then conduct the detection experiment after determining the optimal absorption wavelength and drawing the standard curve. The infrared spectroscopy method uses extraction agents such as carbon tetrachloride or tetrachloroethylene to extract petroleum compounds from the sample, then removes the polar components with substances such as magnesium silicate or silica gel, and then, based on the three-wavelength method, that is, the C-H bond stretching vibration exists at 2960, 2930, and 3030 cm -1 wavelengths for -CH3, -CH2-, and =CH-, qualitative and quantitative analysis is carried out to determine the total petroleum hydrocarbon content. This method can detect alkanes, cycloalkanes, and most aromatic compounds, and has reliability and integrity. However, because the extraction solvents used usually have high toxicity and can produce chlorofluorocarbons, leading to the greenhouse effect, the currently found environmentally friendly alternative solvent is tetrachloroethylene, but it is also difficult to promote due to its high price and low purity, etc. Therefore, to a certain extent, it restricts the development of the infrared method. The gravimetry method first uses volatile solvents such as petroleum ether to extract petroleum hydrocarbon substances in the soil, then pours the extraction solution into containers such as small beakers, places it in a fume hood to evaporate the solvent, and then obtains the mass of the remaining substances in the container by weighing and calculation, which is the TPH content in the soil. This method has the lowest requirements for instrument conditions, but because heavy hydrocarbon substances in crude oil may not be completely extracted, and some light petroleum hydrocarbon components may also volatilize during the solvent evaporation process, thus introducing measurement errors. At the same time, it has low sensitivity and is time-consuming, restricting its application range.

[0012] Inappropriate measurement methods can lead to significantly different measurement results. The final measurement results are also affected by various factors such as each test standard sample and the extraction reagents used. Moreover, the measurement requirements for petroleum hydrocarbon substances vary among different industries and fields 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 choosing a measurement method, factors such as measurement duration, measurement cost, ease of operation, and accuracy requirements of the detection results should be comprehensively considered. In the existing ultraviolet method for determination in the prior art, there are deficiencies such as low measurement 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 n-alkanes (C10-C40) in soil. Accurately determining the oil spill pollution in soil is also the basis for assessing the ecological environment damage caused by oil spill pollution. Summary of the Invention

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

[0015] The present invention aims at the deficiencies in the method for assessing the ecological environment damage caused by oil spill pollution in the prior art, and provides a method for assessing the ecological environment damage caused by oil spill pollution.

[0016] Preferably, the method for assessing the ecological environment damage includes the step of detecting petroleum hydrocarbons in the soil.

[0017] The method for quickly confirming the degree of environmental damage caused by soil oil spill pollution disclosed by the present invention can accurately assess the degree of pollution caused by an oil spill accident to the environment, which is crucial for understanding the severity and scope of the accident. The measurement results of the petroleum 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] 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 soil oil spill pollution, and the method includes:

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

[0021] 2) Detect petroleum hydrocarbons in the sample soil for each sample, and the detection 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 desiccant in a conical flask, add the extractant, shake well, then perform ultrasonic extraction, and centrifuge to collect the supernatant. The extractant is prepared by mixing carbon tetrachloride cyclohexane, hexane, and 1,1,2-trichloro-1,2,2-trifluoroethane or by mixing carbon tetrachloride, pentane, and petroleum ether;

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

[0024] 2.3) Pass the concentrated solution through a magnesium silicate purification column, collect the eluate, and concentrate it to 1 mL for standby;

[0025] 2.4) Take the concentrated solution in step 3) in a cuvette for detection, and calculate the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve;

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

[0027] 4) For each sampling depth, integrate the area of the depth - content curve, and divide the integration result by the total sampling amount at multiple sampling depths as the average content of petroleum hydrocarbons at this sampling point;

[0028] 5) For all sampling points, calculate the comprehensive average content of all detection areas based on the average contents of petroleum hydrocarbons at each sampling point, and evaluate the ecological environment damage 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 this detection point.

[0030] Preferably, in step 5), determine the inflection points of the petroleum hydrocarbon concentrations at each sampling point, calculate the average slope between each sampling point after the inflection point, and determine the pollution depth based on this 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, in step 2.1), the mass ratio of the soil to the desiccant is (1 - 2):(0.5 - 1).

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

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

[0035] Preferably, the mass-volume ratio of the soil, desiccant and the extractant in step 2.1) is 1 g: 2 g: 5 mL. Preferably, step 5 further 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 with 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 this sampling point, and evaluating the ecological environment damage based on the total petroleum hydrocarbon content of the covered area.

[0036] Preferably, 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.

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

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

[0039] Preferably, it further includes evaluating the ecological environment damage according to the calculated petroleum hydrocarbon concentration in the soil.

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

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

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

[0043] The present invention discloses a method for evaluating the ecological environment damage caused by oil spills, and the method includes the steps of detecting petroleum hydrocarbons in soil, including:

[0044] 1) Take the soil to be tested and desiccant in a conical flask, add the extractant, shake and mix evenly, then perform ultrasonic extraction, centrifuge and collect the supernatant. The extractant is prepared by mixing carbon tetrachloride ring, hexane, and trichlorotrifluoroethane or by mixing carbon tetrachloride, pentane, and petroleum ether;

[0045] 2) Repeat step 1, and combine the supernatants extracted twice, and concentrate the volume to 1-2 mL;

[0046] 3) Pass the concentrated solution through a magnesium silicate purification column, collect the eluent, and concentrate it to 1 mL for standby;

[0047] 4) Take the concentrated solution in step 3) for detection in a cuvette, and calculate the concentration of petroleum hydrocarbons in the soil using the 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 loam, brown loam and black soil.

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

[0052] Preferably, the carbon tetrachloride, cyclohexane, and trichlorotrifluoroethane are prepared according to a volume ratio of 1:1:1.

[0053] Preferably, the carbon tetrachloride, pentane, and petroleum ether are prepared according to 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, it further includes evaluating the ecological environment damage according to the calculated concentration of petroleum hydrocarbons in the soil.

[0057] The purpose of the present invention is to provide a method for extracting and detecting petroleum hydrocarbons in soil, aiming at the problems of insufficient detection methods and low accuracy of petroleum hydrocarbons in polluted soil in the prior art.

[0058] The present invention has screened and obtained an extractant suitable for the extraction of petroleum hydrocarbons in various soil types. The standard curve of the petroleum standard concentration solution established by using the extractant of the present invention has a high R 2 value. The extractant of the present invention can efficiently extract petroleum hydrocarbons in various different types of soil, including red loam, brown loam and black soil. The method of the present invention can accurately determine the petroleum hydrocarbon pollution of different types of soil, and the repeatability of the detection is good. According to the method for detecting petroleum hydrocarbons in soil disclosed by the present invention, the ecological environment damage can be further evaluated according to the measured concentration of petroleum hydrocarbons in the soil.

[0059] The method for quickly confirming the degree of environmental damage caused by soil oil spill pollution disclosed by 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 by regularly measuring, it is possible to better understand the diffusion situation of pollutants, and better prevent and control environmental pollution.

[0060] The method for rapidly confirming the degree of environmental damage caused by soil oil spills disclosed in the present invention is an essential part of oil spill assessment, providing important data support for accident response, environmental restoration, legal litigation, and scientific research.

[0061] The method for rapidly confirming the degree of environmental damage caused by soil oil spills disclosed in the present invention is crucial for formulating environmental restoration plans, ensuring that the restoration measures taken are highly targeted and effectively restoring the damaged environment.

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

[0063] The method for rapidly confirming the degree of environmental damage caused by soil oil spills disclosed in the present invention is an important part of environmental scientific research, helping to better understand the environmental behavior and ecological impacts of oil spills.

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

[0065] The method for rapidly confirming the degree of environmental damage caused by soil oil spills disclosed in the present invention can provide the public with accurate information on the content of petroleum hydrocarbons in the environment caused by oil spills, improving the public's awareness and attention to environmental issues and promoting the enhancement of environmental protection awareness. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0067] Figure 2 is a standard curve graph established for the first group of extractants.

[0068] Figure 3 is a standard curve graph established for the second group of extractants.

[0069] Figure 4 is a standard curve graph established for the third group of extractants. DETAILED DESCRIPTION OF THE INVENTION

[0070] The following further describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not intended to limit the present invention.

[0071] As Figure 1 shown, in the embodiments of the present invention, the method for rapidly confirming the degree of environmental damage caused by soil oil spills includes the following steps:

[0072] 1) Determine the target detection area, select a predetermined number of detection points in the target detection area, and perform sampling detections at multiple depths for each detection point;

[0073] During the oil spill detection process, it is impossible to exhaustively sample. Therefore, it is necessary to divide the oil spill area. The specific division granularity is mainly determined according to the detection accuracy. 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. The area to be detected can be divided into grids of a certain length (such as 5 meters, 10 meters, 30, 50, 100, 1000 meters). A sampling point is selected at the center of each grid, and sampling is performed at different depths at this sampling point according to the pollution degree.

[0074] 2) Detect petroleum hydrocarbons in the sample soil for each sample. The detection process includes:

[0075] 2.1) Take a predetermined amount of soil to be tested and desiccant in a conical flask, add an extraction agent, mix well by shaking, then perform ultrasonic extraction, and centrifuge to collect the supernatant. The extraction agent is prepared by mixing carbon tetrachloride, cyclohexane, and 1,1,2-trichloro-1,2,2-trifluoroethane or by mixing carbon tetrachloride, pentane, and petroleum ether;

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

[0077] 2.3) Pass the concentrated solution through a magnesium silicate purification column, collect the eluate, and concentrate it to 1 mL for standby;

[0078] 2.4) Take the concentrated solution in step 3) in a cuvette for detection, and calculate the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve;

[0079] 3) Fit a depth - content curve based on the content of petroleum hydrocarbons 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. A parabola opening downward can be used as the basic curve to fit this curve.

[0080] 4) For each sampling point, integrate the area of its depth - content (depth as the abscissa - content as the ordinate) curve, and divide the integration result by the total sampling amount (measured sample amount) at multiple sampling depths as the average content of petroleum hydrocarbons at this 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 the oil - containing soil, and C(h) is the content of petroleum hydrocarbons per unit mass of soil at depth h in the fitted curve.

[0081] 5) For all sampling points, calculate the comprehensive average content of all detection areas based on the average content of petroleum hydrocarbons at each sampling point, and evaluate the ecological environment damage based on the comprehensive average content of all detection areas (since 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 by combining the area of the detection area). In one implementation, N is the number of sampling points, and Cn is the content of petroleum hydrocarbons at the nth sampling point (the average content here refers to the average content per unit sampling mass).

[0082] Preferably, in step 5), determine the inflection points of the petroleum hydrocarbon content at each sampling point, calculate the average slope between the sampling points after the inflection point, and determine the pollution depth based on this average slope.

[0083] Preferably, step 5 further includes: summarizing the content of petroleum hydrocarbons per unit volume at each detection point, taking the intersection of the depth-content curve at each sampling point with 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 content of petroleum hydrocarbons at this sampling point, and evaluating the ecological environment damage based on the total petroleum hydrocarbon content of the covered area.

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

[0085] Example 1 Preliminary screening of extraction reagents

[0086] Quickly and fully extracting the petroleum hydrocarbons in the soil is the basis for determination, and the linear level of the standard curve established by the extraction reagent used is also an important factor in the determination accuracy. The type and polarity difference 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 ultraviolet determination. A good extractant is required to show the smallest error range in the stability of the ultraviolet absorption determination of the product after dissolving different concentrations of petroleum hydrocarbons on the basis of being able to fully dissolve and extract the petroleum hydrocarbons in the soil.

[0087] In this application, 3 extractants are randomly selected from common petroleum hydrocarbon extractants according to the difference in polarity and non-polarity, and each group of extractants is prepared according to a volume ratio of 1:1:1, and a total of 3 groups of different extractants are obtained. The specific formula is shown in Table 1.

[0088] Table 1: Formulas of different extractants

[0089]

[0090] Example 2 Standard curve situations established by different extraction reagents

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

[0092] Dissolve C10-C40 standard crude oil in the extractants of different groups in Example 1, and prepare an initial concentration of 200 mg / L. Further dilute the concentration gradient with each group of extractants to: 0, 1 mg / L, 2 mg / L, 4 mg / L, 8 mg / L, and 16 mg / L;

[0093] 2) Determination of the ultraviolet luminescence value of the standard concentration solution. When measuring the standard solution each time, take about 0.3 mL and put it into a cuvette for testing on the machine. The measurement wavelength is 254 nm. The control is the extractant without standard crude oil. Each concentration of the standard solution is measured three times. The measurement results of the standard solutions with different concentrations of the extractants in the first group to the third group are shown in Table 2 - Table 4 respectively;

[0094] Table 2: Ultraviolet measurement values of the standard solution of the first group of extractants

[0095]

[0096]

[0097] Table 3: Ultraviolet measurement values of the standard solution of the second group of extractants

[0098] Group 1 mg / L 2 mg / L 4 mg / L 8 mg / L 16 mg / L Absorbance measured for the first time 0.028 0.055 0.136 0.311 0.626 Absorbance measured for the second time 0.035 0.061 0.155 0.278 0.516 Absorbance measured for the third time 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: Ultraviolet measurement values of the standard solution of the third group of extractants

[0100] Group 1 mg / L 2 mg / L 4 mg / L 8 mg / L 16 mg / L Absorbance measured for the first time 0.033 0.077 0.128 0.263 0.646 Absorbance measured for the second time 0.026 0.074 0.135 0.293 0.592 Absorbance measured for the third time 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 the crude oil standard curve: Use the average absorbance value measured for each group as the ordinate and the concentration of the crude oil standard solution as the abscissa to plot the standard curve, obtain the corresponding standard curve equation, and calculate the correlation coefficient R of the standard curve corresponding to each extractant 2 value, and the results are as Figures 2 - 4 shown.

[0102] Judging from the obtained results, the linear result of the first group of extractants is the best, and the R 2 value is 0.9996, indicating that as an extractant, after dissolving crude oil of various different concentrations, the ultraviolet absorbance value is less affected, and it performs the best among the three extractants provided.

[0103] Extraction effect of the extraction reagent in Example 3 on petroleum pollution in different types of soil

[0104] 2.1 Selection of the tested soil

[0105] Select three different types of uncontaminated soil, including red loam soil, brown loam soil, and black soil. Among them, the red loam soil is taken from a certain city in Jiangxi Province, the brown loam soil is taken from a certain city in Shanxi Province, and the black soil is taken from a certain city in Heilongjiang Province. To ensure that the properties of the tested soils obtained are as consistent as possible, the sampling depth of the soil is about 150 cm from the surface, and the five-point sampling method is used for soil collection.

[0106] 2.2 Treatment of Tested Soils

[0107] After transporting the collected soil back to the laboratory, remove possible stones, debris and other sundries, place it in a freeze-drying instrument to remove moisture, pass it through a 2 mm sieve, and then air-dry it naturally and grind it for later use.

[0108] 2.3 Establishment of Soil Pollution Model

[0109] Dissolve C10-C40 standard crude oil in petroleum ether (boiling point 30-60 °C) according to the mass-volume ratio of 1:10, and add it to the above different types of soil according to the mass ratio of (0.2 mg:100) g, that is, add 0.2 mg of C10-C40 standard crude oil to 100 g of soil, stir well, and place the treated contaminated soil sample in a fume hood for 2-4 hours, and turn the soil appropriately during this period. After the petroleum ether volatilizes, the contaminated soil is obtained.

[0110] 2.4 Extraction and Determination of Petroleum Hydrocarbons in Contaminated Soil

[0111] 1) Accurately weigh 2 g of each of the prepared contaminated different types of soil (red loam soil, brown loam soil, and black soil) and 1 g of anhydrous magnesium sulfate as a desiccant into a conical flask, and conduct 3 parallel determinations for each type of soil;

[0112] 2) Add 10 mL of the first group of extractants (carbon tetrachloride: cyclohexane: 1,1,2-trichlorotrifluoroethane volume ratio of 1:1:1), shake well, and then perform ultrasonic treatment for extraction for 5-10 min; centrifuge to collect the supernatant;

[0113] 3) Then add 5 mL of the first group of extractants to the centrifugal precipitate, shake well, and perform ultrasonic treatment for extraction for 5-10 min; centrifuge to collect the supernatant;

[0114] 4) Combine the supernatants collected in step 2) and step 3), and concentrate them to a volume of 1 mL with a concentrator;

[0115] 5) Pass the concentrated solution obtained in step 4) through a magnesium silicate purification column, elute the purification column with n-hexane, collect the eluate, and concentrate it to 1 mL for later use.

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

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

[0118] Group Red loam Brown loam Black soil OD value of the first group 0.073 0.066 0.071 OD value of the first group 0.062 0.064 0.068 OD value of the first group 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] Judging from the measurement results, the first extractant can extract petroleum hydrocarbons in three different types of soils very well.

[0120] Example 4 Repeatability determination of extraction reagent

[0121] 1) Randomly select a pollution-free soil of undetermined type for the repeatability determination of the extractant. The soil is taken from the suburbs of Tianjin, and the soil sampling depth is about 150 cm from the ground surface. The five-point sampling method is used for soil collection.

[0122] 2) After transporting the collected soil back to the laboratory, remove possible stones, debris and other sundries, place it in a freeze-drying instrument to remove moisture, pass it through a 2-mm sieve, and then air-dry it naturally and grind it for later use.

[0123] 3) Dissolve C10-C40 standard crude oil in petroleum ether (boiling point 30-60 °C) according to the mass-volume ratio of 1:10. Add it to the above soil according to the mass ratio of (0.4 mg: 100 g and 0.8 mg: 100 g) respectively, that is, add 0.4 mg and 0.8 mg of C10-C40 standard crude oil to 100 g of soil, stir well, and place the treated contaminated soil sample in a fume hood for 2-4 hours. During this period, turn the soil appropriately. After the petroleum ether volatilizes, obtain the contaminated soil.

[0124] 4) Accurately take 2 g of each prepared contaminated soil and 1 g of anhydrous magnesium sulfate as a desiccant into a conical flask, and conduct 15 parallel determinations for each soil;

[0125] 5) Add 10 mL of the first group of extractants (carbon tetrachloride: cyclohexane: 1,1,2-trichlorotrifluoroethane volume ratio of 1:1:1), shake well, and then perform ultrasonic treatment for extraction for 5-10 min; centrifuge to collect the supernatant;

[0126] 6) Then add 5 mL of the first group of extractants to the centrifugal precipitate, shake well, and perform ultrasonic treatment for extraction for 5-10 min; centrifuge to collect the supernatant;

[0127] 7) Combine the supernatants collected in steps 2) and 3), and concentrate it to a volume of 1 mL with a concentrator;

[0128] 8) Pass the concentrated solution obtained in step 4) through a magnesium silicate purification column, elute the purification column with n-hexane, collect the eluate, and concentrate it to 1 mL for standby.

[0129] 9) Take 0.3 mL of the concentrated solution prepared in step 5) and place it in a colorimetric cell for on-machine testing. The measurement wavelength is 254 nm. After measuring the corresponding OD value, calculate the average value, and further calculate the content of petroleum hydrocarbons in the soil using the established standard curve. The measurement and calculation results are shown in Tables 6 - 7 below.

[0130] Table 6: Results of OD value for repeatability detection 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 is calculated that the standard deviation SD is 0.01, and the detection precision reaches 4.96%, indicating good repeatability. The detection result is 3.58 mg / kg.

[0133] Table 7: Results of OD value for repeatability detection 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 is calculated that the standard deviation SD is 0.01, and the detection precision reaches 2.85%, indicating good repeatability. The detection result is 7.13 mg / kg.

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

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

Claims

1. A method for quickly confirming the degree of environmental damage caused by soil oil spill pollution, characterized in that The method includes: 1) Determine the target detection area, select a predetermined number of detection points in the target detection area, and perform sampling detections at multiple depths for each detection point; 2) For each sample, detect the petroleum hydrocarbons in the sample. The detection process includes: 2.1) Take a predetermined amount of soil to be measured and desiccant in a conical flask, add an extractant, mix well by shaking, then perform ultrasonic extraction, centrifuge to collect the supernatant. The extractant is prepared by mixing carbon tetrachloride, cyclohexane, and 1,1,2-trichloro-1,2,2-trifluoroethane, and the carbon tetrachloride, cyclohexane, and 1,1,2-trichloro-1,2,2-trifluoroethane are formulated according to a volume ratio of 1:1:1; 2.2) Repeat step 2.1), and combine the supernatants extracted twice, and concentrate the volume to 1 - 2 mL; 2.3) Pass the concentrated solution through a magnesium silicate purification column, collect the eluate, and concentrate it to 1 mL for standby; 2.4) Take the concentrated solution in step 2.3) in a cuvette for detection, and calculate the content of petroleum hydrocarbons in the soil using the petroleum hydrocarbon standard curve; 3) Fit the depth-content curve based on the contents of petroleum hydrocarbons measured at multiple depths at each sampling point; 4) Integrate the area of the depth-content curve of each sampling point, and divide the integration result by the total sampling volume at multiple sampling depths as the average content of petroleum hydrocarbons at this sampling point; 5) For all sampling points, calculate the comprehensive average content of all detection areas based on the average content of petroleum hydrocarbons at each sampling point, and evaluate the ecological environment damage based on the comprehensive average content of all detection areas; The petroleum hydrocarbons are C10 - C40 petroleum hydrocarbons.

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, wherein In step 5), determine the inflection points of the petroleum hydrocarbon content with depth at each sampling point, calculate the average slope between each sampling point after the inflection point, and determine the pollution depth based on this average slope.

4. The method according to claim 1, wherein 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, Step 5) further includes: summarizing the content of petroleum hydrocarbons per unit volume at each detection point, taking the intersection point of the depth-content curve at each sampling point with 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 this area based on the total volume of the polluted area and the average content of petroleum hydrocarbons at this sampling point, and evaluating the ecological environment damage based on the total petroleum hydrocarbon content of the covered area.

6. The method according to claim 1, wherein The eluate in step 2.3) is n-hexane.

7. According to the method as claimed in any one of claims 1-6, characterized in that, The detection wavelength in step 2.4) is 254 nm.

8. A method for detecting the concentration of spilled oil in oil-spill polluted soil, characterized in that, The method includes steps 1) - 4) in claim 1.

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