Method for tracing leaked oil in water

Abstract

The present disclosure relates to a method for tracing leaked oil in water, which comprises the following steps: performing chromatographic analysis on an oil phase in a water sample to be tested to obtain a determination spectrum, determining a similarity S between the determination spectrum and a characteristic spectrum of at least one oil that may leak into water, determining a type of leaked oil in the water sample to be tested according to the similarity S, and determining a source of the leaked oil based on the determined type of the leaked oil. The method can directly, quickly, efficiently and sensitively determine the source of the leaked oil in the water sample to be tested, which helps to find safety hazards in time, ensures the production safety of a refinery, and at the same time, quickly determines the source of the leaked oil, facilitates timely treatment of the source of the leaked oil, and avoids pollution and waste of water resources.

Description

Technical Field

[0001] This disclosure relates to the field of petrochemical technology, and more specifically, to a method for tracing the source of oil spills in water. Background Technology

[0002] In recent years, with the increasing heaviness and deterioration of crude oil, its corrosive and destructive effects on refining equipment have also intensified, leading to a growing problem of oil spills in water. Statistics show that over 85% of refining equipment in my country's refining systems suffers from oil spills. When oil spills into the water system, it causes varying degrees of pollution. The specific degree of pollution depends on the volume and duration of the leak; the larger the volume and the longer the duration, the more severe the pollution and the greater the economic losses.

[0003] When an oil leak occurs in a water system, if the source of the leak can be located in time, the leaking equipment or water quality can be treated in a short period of time to prevent the leak from worsening, ensure the normal operation of the equipment, and reduce the degree of water pollution.

[0004] In related technologies, for detecting oil leaks in water, the most commonly used methods, in addition to monitoring changes in the physicochemical properties of the water, also include monitoring changes in the oil content in the water based on changes in electrical and optical signals.

[0005] However, the above methods are all vague judgment methods, which can only determine whether there is leaked oil in the water, but cannot determine the source of the leak. Summary of the Invention

[0006] The purpose of this disclosure is to address the problem that existing methods can only determine whether there is leaked oil in the water, but cannot determine the source of the leak, and to provide a method for tracing the source of leaked oil in water.

[0007] To achieve the above objectives, this disclosure provides a method for tracing the source of oil spills in water, the method comprising:

[0008] Obtain a water sample to be tested, and separate the oil phase from the water sample to be tested as a test sample;

[0009] The test sample is subjected to chromatographic analysis to obtain the chromatogram of the test sample;

[0010] Determine the similarity S between the measured spectrum of the test sample and the characteristic spectrum of at least one preset oil, wherein the at least one preset oil includes oil that may leak into water;

[0011] Based on the similarity S, the type of leaked oil in the water sample to be tested is determined;

[0012] Based on the identified type of leaked oil, the source of the leak is determined.

[0013] Optionally, the measured spectrum and the characteristic spectrum have the same detection time, and determining the similarity S between the measured spectrum of the test sample and the characteristic spectrum of at least one preset oil includes:

[0014] Based on the detection duration of the measured spectrum, the measured spectrum is divided into n measurement regions E according to a preset time interval. xi And determine each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Where n is a positive integer, 1≤i≤n;

[0015] Based on the detection time of each feature map, each feature map is divided into n control regions E according to the preset time interval. yi and determine each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i ;

[0016] Based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i The similarity S between the measured spectrum and each of the characteristic spectra is determined.

[0017] Optionally, the preset time interval is 0.02 to 0.5 seconds, and n is an integer from 4800 to 120000.

[0018] Optionally, the measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determining the similarity S between the measured spectrum and each of the feature spectra includes:

[0019] The n measurement regions E in the measurement spectrum xi The measurement area is divided into m groups, and based on each measurement area E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj Where m is a positive integer, 1≤m≤n, 1≤j≤m;

[0020] Determine the measurement region group G for each group after interference removal. xj The average measurement signal intensity x of all measured chromatographic peaks j ;

[0021] The n control regions E in each of the aforementioned feature maps yi The region was divided into m control regions, and based on each control region E... yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj ;

[0022] Determine the interference-free control region group G for each group. yj The average standard signal intensity y of all reference chromatographic peaks j ;

[0023] Based on each group of interference-free measurement regions G xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks j Determine the similarity S between the measured spectrum and each of the characteristic spectra. m .

[0024] Optionally, m is an integer from 20 to 200, and each group of measurement regions includes 250 to 1000 measurement regions E. xi Each control region group includes 250 to 1000 control regions E. yi And in each group of measurement areas, measurement area E xi The number of control regions E in each control region group yi The number of them is the same.

[0025] Optionally, the measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj ,include:

[0026] Based on n measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Determine the n measurement regions E xi The maximum measured signal intensity xmax and minimum measured signal intensity x min ;

[0027] Determine the intensity x of each measured signal i With the minimum measured signal intensity x min The difference is used to obtain the measurement region E of each region. xi The corrected measurement signal intensity x for all measured chromatographic peaks i校 ;

[0028] The calibrated measurement signal intensity x in each measurement area group i校 Less than (x) max -x min The measurement regions with a ratio of 5 ≤ a ≤ 10 are discarded as interference regions, resulting in the interference-free measurement region groups G. xj ;

[0029] The basis for each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj ,include:

[0030] Based on n control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determine the n control regions E yi The maximum standard signal strength y in max and minimum standard signal strength y min ;

[0031] Determine the signal strength y of each standard i With the minimum standard signal strength y min The difference is used to obtain the control regions E. yi Correction standard signal intensity y of all reference chromatographic peaks i校 ;

[0032] The calibration standard signal intensity y in each control region group i校 Less than (y) max -y min The control regions with a ratio of 5 / a (5≤a≤10) are discarded as interference regions, resulting in the interference-free control region groups G. yj .

[0033] Optionally, based on each group of interference-free measurement regions G xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yjThe average standard signal intensity y of all reference chromatographic peaks j The similarity S between the measured spectrum and each of the characteristic spectra is calculated according to the following formula. m :

[0034]

[0035] Where m represents the measurement region group G in the measurement spectrum after interference removal. xj The number of or interference-free control regions G in the feature map yj The number of each measurement region group G after interference removal, j represents the number of each measurement region group G after interference removal. xj The serial number or each interference-free control region group G yj The serial number.

[0036] Optionally, the method further includes: acquiring a feature spectrum of at least one preset oil; wherein the test conditions for acquiring the feature spectrum are the same as the test conditions for acquiring the measurement spectrum.

[0037] Optionally, the method further includes: acquiring feature spectra of all oils that may leak into the water, establishing a feature spectrum library including the feature spectra of all oils, and determining the similarity S between the measured spectrum of the test sample and the feature spectrum of at least one preset oil, including:

[0038] Determine the similarity S between the measured spectrum of the test sample and each of the feature spectra in the feature spectrum library.

[0039] Optionally, determining the type of leaked oil in the water sample to be tested based on the similarity S includes:

[0040] The similarity S between the measured spectrum and each of the feature spectra is determined sequentially, and the preset oil type corresponding to the feature spectrum with the largest similarity S value and greater than 0.99 is determined as the leaked oil type in the water sample to be tested.

[0041] Optionally, separating the oil phase from the water sample to be tested includes:

[0042] The water sample to be tested is subjected to solid-phase microextraction, wherein the solid-phase microextraction includes direct extraction and / or headspace extraction.

[0043] Optionally, the conditions for direct extraction include: direct extraction time of 1 to 20 min, direct extraction temperature of 25 to 60 °C, desorption time of 0.5 to 5 min, and desorption temperature of 250 to 280 °C.

[0044] The headspace extraction conditions include: headspace extraction time of 5–20 min, headspace extraction temperature of 30–70 °C, desorption time of 0.5–5 min, and desorption temperature of 250–280 °C.

[0045] Optionally, the chromatographic analysis is gas chromatography analysis, and the operating conditions of the gas chromatography analysis include: FID detector, splitless injection, injection volume of 0.1-2.0 μl, carrier gas of helium, chromatographic column of 5 m × 530 μm × 0.15 μm high-temperature stainless steel capillary column, sampling frequency of 2-50 Hz, constant flow rate of 1-25 mL / min, initial temperature of 35-120 °C, heating rate of 2-20 °C / min, final temperature of 250-430 °C, and holding time of 5-15 min.

[0046] Optionally, the concentration of the oil phase in the water sample to be tested is 1 mg / L to 100 mg / L.

[0047] The method for tracing the source of leaked oil in water provided by this disclosure involves chromatographic analysis of the oil phase in the water sample to be tested, obtaining a chromatogram, determining the similarity (S) between this chromatogram and the characteristic chromatogram of at least one oil that may have leaked into the water, and identifying the type of leaked oil in the water sample based on the similarity (S). Finally, based on the identified type of leaked oil, the source of the leak is determined. This method can directly, quickly, efficiently, and with high sensitivity identify the source of leaked oil in the water sample to be tested, which helps to promptly detect potential safety hazards, ensure the production safety of refineries, and facilitate timely handling of leaks, avoiding water pollution and waste.

[0048] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 The exemplary embodiments of this disclosure show the characteristic spectra of oil in waste oil C1001 and oil in raw material C2001. Detailed Implementation

[0051] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0052] This disclosure provides a method for tracing the source of leaked oil in water. The method includes: acquiring a water sample to be tested and separating an oil phase from the water sample as a test sample; performing chromatographic analysis on the test sample to obtain a chromatogram of the test sample; determining the similarity S between the chromatogram of the test sample and the characteristic chromatogram of at least one preset oil, wherein the at least one preset oil includes oil that may leak into the water; determining the type of leaked oil in the water sample to be tested based on the similarity S; and determining the leak source of the leaked oil based on the determined type of leaked oil.

[0053] In this disclosure, specifically, the water sample to be tested can be circulating water from a refinery's circulating water system. The circulating water system may include multiple oil-water heat exchangers, and the water media in these heat exchangers can be independent of each other or fluidly connected to each other. The preset oil sample can be a single component or a mixture of multiple components. When the preset oil sample is a mixture of multiple components, it is preferably a mixture of all oil components in the refinery equipment corresponding to each oil-water heat exchanger.

[0054] The method for tracing the source of leaked oil in water disclosed herein involves performing chromatographic analysis on the oil phase of a water sample to obtain a chromatogram. The similarity (S) between this chromatogram and the characteristic chromatogram of at least one potentially leaked oil substance is then determined. Based on the similarity (S), the type of leaked oil in the water sample is identified. Finally, based on the identified type of leaked oil, the source of the leak is determined. This method can directly, rapidly, efficiently, and with high sensitivity identify the source of leaked oil in a water sample, helping to promptly detect potential safety hazards and ensure the production safety of refineries. Furthermore, the rapid identification of the leak source facilitates timely handling of the leak, preventing water pollution and waste.

[0055] According to this disclosure, the measurement spectrum and the characteristic spectrum can be obtained using the same detection method under the same detection conditions; therefore, the measurement spectrum and the characteristic spectrum can have the same detection time. When determining the similarity S between the measurement spectrum of the test sample and the characteristic spectrum of at least one preset oil, the measurement spectrum can first be divided into n measurement regions E according to a preset time interval based on the detection time of the measurement spectrum. xi And determine each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Where n is a positive integer, 1≤i≤n; then, based on the detection time of each feature map, each feature map is cut into n control regions E according to the preset time interval. yi and determine each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range iFinally, based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i The similarity S between the measured spectrum and each of the characteristic spectra is determined.

[0056] According to this disclosure, the preset time interval and the value of n can vary within a certain range. For example, the preset time interval can be 0.02 to 0.5 seconds, and n can be an integer from 4800 to 120000.

[0057] In determining the similarity between a measured chromatogram and a characteristic chromatogram, a common method is to compare the determination retention time of the chromatographic peak in the measured chromatogram with the standard retention times of each reference chromatographic peak in the characteristic chromatogram. A higher degree of overlap between the determination and standard retention times indicates a higher similarity between the measured and characteristic chromatograms. However, when the chemical composition of the sample is complex, hydrocarbons with a high number of carbon atoms are difficult to separate in a chromatographic system. Therefore, it is difficult to distinguish hydrocarbons with a high number of carbon atoms in the sample based on the retention time of chromatographic peaks, resulting in low accuracy of existing similarity determination methods.

[0058] In the method provided in this disclosure, the measured spectrum and the characteristic spectrum are divided into partitions, and then the similarity between the measured spectrum and the characteristic spectrum is determined by the signal intensity of all chromatographic peaks in the corresponding partition. It is not necessary to accurately distinguish each chemical component in the sample based on the retention time. Even when the chromatographic peaks corresponding to multiple chemical components overlap, the similarity between the measured spectrum and the characteristic spectrum can be accurately determined. Therefore, the above method has high accuracy.

[0059] According to this disclosure, the measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determining the similarity S between the measured spectrum and each of the feature spectra may include: matching the n measured regions E in the measured spectrum. xi The measurement area is divided into m groups, and based on each measurement area E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj Where m is a positive integer, 1≤m≤n, 1≤j≤m; determine the measurement region group G for each group after interference removal.xj The average measurement signal intensity x of all measured chromatographic peaks j ; the n control regions E in each of the aforementioned feature maps yi The region was divided into m control regions, and based on each control region E... yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj Determine the control region group G after interference removal for each group. yj The average standard signal intensity y of all reference chromatographic peaks j Based on the interference-free measurement region group G for each group xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks j Determine the similarity S between the measured spectrum and each of the characteristic spectra. m .

[0060] According to this disclosure, the value of m and the number of regions included in each region group can vary within a certain range. For example, m can be an integer from 20 to 200, and each measurement region group can include 250 to 1000 measurement regions E. xi Each group of control regions may include 250 to 1000 control regions E. yi And in each group of measurement areas, measurement area E xi The number of control regions E in each control region group yi The number of them is the same.

[0061] According to this disclosure, the measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj It may include: based on n measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Determine the n measurement regions E xi The maximum measured signal intensity x max and minimum measured signal intensity x min Determine the intensity x of each measured signal. i With the minimum measured signal intensity x min The difference is used to obtain the measurement region E of each region.xi The corrected measurement signal intensity x for all measured chromatographic peaks i校 ; The corrected measurement signal intensity x in each measurement area group i校 Less than (x) max -x min The measurement regions with a ratio of 5 ≤ a ≤ 10 are discarded as interference regions, resulting in the interference-free measurement region groups G. xj .

[0062] The basis for each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj It may include: based on n control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determine the n control regions E yi The maximum standard signal strength y in max and minimum standard signal strength y min Determine the strength y of each standard signal. i With the minimum standard signal strength y min The difference is used to obtain the control regions E. yi Correction standard signal intensity y of all reference chromatographic peaks i校 ; The corrected standard signal intensity y in each control region group i校 Less than (y) max -y min The control regions with a ratio of 5 / a (5≤a≤10) are discarded as interference regions, resulting in the interference-free control region groups G. yj .

[0063] According to this disclosure, the determination region group G can be based on each group of interference-free measurement regions. xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks j The similarity S between the measured spectrum and each of the characteristic spectra is calculated according to the following formula. m :

[0064]

[0065] Where m represents the measurement region group G in the measurement spectrum after interference removal. xj The number of or interference-free control regions G in the feature map yjThe number of each measurement region group G after interference removal, j represents the number of each measurement region group G after interference removal. xj The serial number or each interference-free control region group G yj The serial number.

[0066] According to this disclosure, the method may further include: acquiring a characteristic spectrum of at least one preset oil; wherein the test conditions for acquiring the characteristic spectrum are the same as the test conditions for acquiring the measured spectrum.

[0067] According to this disclosure, the method may further include: acquiring feature maps of all oils that may leak into the water, establishing a feature map library including the feature maps of all oils, and determining the similarity S between the measurement map of the test sample and the feature map of at least one preset oil includes: determining the similarity S between the measurement map of the test sample and each of the feature maps in the feature map library.

[0068] According to this disclosure, determining the type of leaked oil in the water sample to be tested based on the similarity S may include: sequentially judging the magnitude of the similarity S between the measured spectrum and each of the feature spectra, and determining the preset oil type corresponding to the feature spectrum with the largest similarity S value and greater than 0.99 as the type of leaked oil in the water sample to be tested.

[0069] According to this disclosure, separating the oil phase from the water sample to be tested can include: performing solid-phase microextraction (SPE) on the water sample, wherein the SPE includes direct extraction and / or headspace extraction. The fiber head used for SPE can be conventional, for example, a 100 μm polydimethylsiloxane (PDMS) probe. SPE is solvent-free, rapid, and convenient, avoiding environmental pollution caused by conventional extraction methods and shortening analysis time.

[0070] According to this disclosure, the conditions for direct extraction may include: a direct extraction time of 1–20 min, a direct extraction temperature of 25–60 °C, a desorption time of 0.5–5 min, and a desorption temperature of 250–280 °C; the conditions for headspace extraction may include: a headspace extraction time of 5–20 min, a headspace extraction temperature of 30–70 °C, a desorption time of 0.5–5 min, and a desorption temperature of 250–280 °C.

[0071] According to this disclosure, the chromatographic analysis can be gas chromatography analysis, and the operating conditions of the gas chromatography analysis may include: FID detector, splitless injection, injection volume of 0.1 to 2.0 μl, carrier gas of helium, chromatographic column of 5 m × 530 μm × 0.15 μm high-temperature stainless steel capillary column, sampling frequency of 2 to 50 Hz, constant flow rate of 1 to 25 mL / min, initial temperature of 35 to 120 °C, heating rate of 2 to 20 °C / min, final temperature of 250 to 430 °C, and holding time of 5 to 15 min.

[0072] According to this disclosure, the concentration of the oil phase in the water sample to be tested can be from 1 mg / L to 100 mg / L.

[0073] The present disclosure is further illustrated below by means of embodiments, but the present disclosure is not limited thereto. Unless otherwise specified, the raw materials, reagents, instruments, and equipment involved in the embodiments of the present disclosure can all be obtained by purchase. Unless otherwise specified, the experimental methods involved in the embodiments of the present disclosure can all be conventional methods in the art.

[0074] In the embodiments of this disclosure, the chromatographic methods used for chromatographic analysis are all gas chromatography, and the chromatographic conditions include: FID detector, splitless injection, injection volume of 0.5 μl, carrier gas of helium, chromatographic column of 5 m × 530 μm × 0.15 μm high-temperature stainless steel capillary column, sampling frequency of 10 Hz, constant flow rate of 20 mL / min, column temperature program of 100 °C held for 0 min, temperature increase rate of 10 °C / min to 400 °C, and final temperature held for 10 min.

[0075] Example 1

[0076] This embodiment is used to illustrate the method for tracing the source of leaked oil in water disclosed in this invention.

[0077] Step 101: Take two water samples from different locations in the circulating water system of a refinery's three-catalytic converter unit, and perform headspace extraction on each sample to separate the oil phase, which will be used as the test sample. The headspace extraction uses a 100 μm polydimethylsiloxane (PDMS) probe, a 20 mL headspace vial volume, a 10 mL extraction solution volume, a 15 min headspace extraction time, a 45 °C extraction temperature, a 2 min desorption time, and a 250 °C desorption temperature at the inlet.

[0078] Step 102: Perform chromatographic analysis on each test sample using the above chromatographic conditions to obtain the determination chromatogram of each test sample.

[0079] Step 103: Based on the detection time (40 min) of each chromatogram, each chromatogram is divided into 24,000 measurement regions at 0.1 s intervals, and the measurement signal intensity of all chromatographic peaks in each measurement region is determined. Due to the large number of measurement regions, for simplicity, this embodiment does not list the measurement signal intensity of all chromatographic peaks in each measurement region of each chromatogram. However, as an example, Table 1 shows the measurement signal intensity of all chromatographic peaks in measurement regions 3701 to 3710 of the chromatogram of water sample 1.

[0080] Table 1

[0081] Measurement area number Measure signal strength 3701 14399 3702 14521 3703 15212 3704 15877 3705 15907 3706 16091 3707 16175 3708 16389 3709 16491 3710 16510

[0082] Step 104: Divide the 24,000 measurement regions in the measurement spectrum of water sample 1 into 200 measurement region groups, with each group containing 120 measurement regions. Analyze the measurement spectrum to determine the maximum signal intensity x among the 24,000 measurement regions in the measurement spectrum of water sample 1. max The minimum signal strength x is 148058. min The value is 0. Based on the measured signal intensity of 24,000 measurement areas, the intensity x of each measured signal is determined. i With minimum measured signal intensity x min The difference is used to obtain the corrected measurement signal intensity x for all measured chromatographic peaks in each measurement region. i校 Due to the large number of measurement areas, for the sake of simplicity, this embodiment does not list the calibration measurement signal intensity of all measured chromatographic peaks in each measurement area one by one.

[0083] x will be included in each measurement area group i校 <(x) max -x min The measurement area of ​​14806 (10 / 10) was discarded as an interference area, resulting in the groups of measurement areas after interference removal in the chromatogram of the water sample 1. The average measurement signal intensity of all chromatographic peaks in each group of measurement areas after interference removal was then determined. Due to the large number of peaks, for the sake of simplicity, this embodiment does not list each group of measurement areas after interference removal.

[0084] Repeat step 104 to determine the average measurement signal intensity of each measurement region group after interference removal and all measurement chromatographic peaks in each measurement region group after interference removal in the measurement chromatogram of water sample 2.

[0085] Step 105: Obtain the characteristic spectra of various types of oils in the three catalytic converters of the refinery, namely, the characteristic spectra of oils in sludge C1001, feedstock C2001, slurry cooler E213, primary reflux cooler E215, sealing oil cooler E216, absorber reflux cooler E308, and compressor #2. The characteristic spectra of oils in sludge C1001 and feedstock C2001 are as follows: Figure 1 As shown.

[0086] The characteristic chromatograms of each oilseed can be predetermined. The determination method is as follows: take each oilseed, perform chromatographic analysis under the above chromatographic conditions, and obtain the characteristic chromatograms of each oilseed.

[0087] Step 106: Based on the detection time (40 min) of each characteristic spectrum, each characteristic spectrum is divided into 24,000 control regions at 0.1 s time intervals, and the standard signal intensity of all control chromatographic peaks in each control region is determined. Due to the large number of oil types and control regions in each oil characteristic spectrum, for simplicity, this embodiment does not list the standard signal intensities of all control chromatographic peaks in all control regions of each oil characteristic spectrum. However, as an example, Table 2 shows the standard signal intensities of all control chromatographic peaks in control regions 3701 to 3710 of the characteristic spectrum of the oil in the reflux cooler E308 of absorption tower two.

[0088] Table 2

[0089] Reference area number Standard signal strength 3701 14413 3702 14492 3703 15182 3704 15877 3705 15955 3706 16155 3707 16126 3708 16455 3709 16557 3710 16477

[0090] Step 107: Divide the 24,000 control regions in the characteristic chromatograms of each oil into 200 control region groups. Each control region group includes 120 control regions. Following the method in Step 104, determine the interference-free control region groups for each oil's characteristic chromatogram, as well as the average standard signal intensity of all control chromatographic peaks within each interference-free control region group. Due to the large number of regions, for the sake of simplicity, this embodiment does not list each interference-free control region in the characteristic chromatograms of each oil.

[0091] Step 108: For a single water sample and a single oil sample, based on the interference-free measurement region group G for each group... xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks jThe similarity S between the measured spectrum and the feature spectrum is calculated according to the following formula. m :

[0092]

[0093] Where m represents the measurement region group G in the measurement spectrum after interference removal. xj The number or feature map of the control region group G after interference removal yj The number of each measurement region group G after interference removal, j represents the number of each measurement region group G after interference removal. xj The serial number or each interference-free control region group G yj The serial number.

[0094] Repeat step 108 to determine the similarity S between each measured spectrum and the characteristic spectrum of each oilseed. m The similarity S between each measured spectrum and the characteristic spectrum of each oilseed is determined sequentially. m The numerical value of the similarity S, and the similarity S m The oil type corresponding to the feature spectrum with the largest value greater than 0.99 is identified as the leaked oil type in the corresponding water sample to be tested. Based on the identified leaked oil type, the leak source of the leaked oil is determined, as shown in Table 3.

[0095] Table 3

[0096]

[0097] As shown in Table 3, the similarity Sm value between the measured spectrum of water sample 1 and the characteristic spectrum of oil in reflux cooler E308 of absorption tower 2 is the highest and greater than 0.99. Therefore, it is determined that the leaked oil in water sample 1 is the oil in reflux cooler E308 of absorption tower 2, and the leakage source of the leaked oil in water sample 1 is determined to be reflux cooler E308 of absorption tower 2.

[0098] The similarity Sm value between the measurement spectrum of water sample 2 and the characteristic spectrum of oil in reflux cooler E215 is the highest and greater than 0.99. Therefore, it is determined that the leaking oil in water sample 2 is the oil in reflux cooler E215, and the leakage source of the leaking oil in water sample 2 is reflux cooler E215.

[0099] Example 2

[0100] Following the method in Example 1, the similarity S between any two characteristic maps of the following materials were calculated: the characteristic map of oil in sludge C1001, the characteristic map of oil in raw material C2001, the characteristic map of oil in oil slurry cooler E213, the characteristic map of oil in reflux cooler E215, the characteristic map of oil in sealing oil cooler E216, the characteristic map of oil in reflux cooler E308 of absorption tower 2, and the characteristic map of oil in compressor #2. m As shown in Table 4.

[0101] Table 4

[0102] <![CDATA[Similarity S m > C1001 C2001 E215 E216 E307 E213 compressor C1001 1 0.173 0 0 0 0 0 C2001 0.173 1 0 0 0 0 0 E215 0 0 1 0.138 0 0.003 0 E216 0 0 0.138 1 0 0 0 E307 0 0 0 0 1 0 0 E213 0 0 0.003 0 0 1 0.002 compressor 0 0 0 0 0 0.002 1

[0103] As shown in Table 4, the method disclosed herein can accurately and sensitively distinguish between different oils.

[0104] Comparative Example

[0105] Following the method below, calculate the similarity S between any two characteristic spectra of the following: oil in sludge C1001, oil in raw material C2001, oil in slurry cooler E213, oil in first-stage reflux cooler E215, oil in sealing oil cooler E216, oil in second-stage reflux cooler E308 of absorber tower, and oil in compressor #2.

[0106] (1) Based on the detection time (40 min) of each characteristic spectrum, each characteristic spectrum was divided into 24,000 control regions at a time interval of 0.1 s, and the standard signal intensity of all control chromatographic peaks in each control region was determined.

[0107] (2) For any two feature maps, based on each control region E in feature map A ai The standard signal intensity a of all reference chromatographic peaks i and each control region E in feature map B bi The standard signal intensity b of all reference chromatographic peaks i The similarity S between any two feature maps is calculated using the following formula:

[0108]

[0109] Where n represents the number of control regions in the feature map, and j represents the sequence number of each control region. The calculation results are shown in Table 5.

[0110] Table 5

[0111] Similarity S C1001 C2001 E215 E216 E307 E213 compressor C1001 1 0.972 0.556 0.774 0.558 0.885 0.996 C2001 0.972 1 0.463 0.775 0.495 0.874 0.97 E215 0.556 0.463 1 0.714 0.872 0.726 0.574 E216 0.774 0.775 0.714 1 0.603 0.808 0.797 E307 0.558 0.495 0.872 0.603 1 0.775 0.577 E213 0.885 0.874 0.726 0.808 0.775 1 0.909 compressor 0.996 0.97 0.574 0.797 0.577 0.909 1

[0112] As shown in Table 5, the conventional cosine similarity algorithm has poor distinguishability among different oils.

[0113] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0114] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0115] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for tracing the source of oil spills in water, characterized in that, The method includes: Obtain a water sample to be tested, and separate the oil phase from the water sample to be tested as a test sample; The test sample is subjected to chromatographic analysis to obtain the chromatogram of the test sample; Based on the detection duration of the measured spectrum, the measured spectrum is divided into n measurement regions E according to a preset time interval. xi And determine each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Where n is a positive integer, 1≤i≤n; Based on the detection time of at least one preset oil feature spectrum, each feature spectrum is divided into n control regions E according to the preset time interval. yi and determine each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Wherein, the at least one preset oil includes oil that may leak into water, and the measured spectrum and the feature spectrum have the same detection duration; Based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i The similarity S between the measured spectrum and each of the feature spectra is determined. Based on the similarity S, the type of leaked oil in the water sample to be tested is determined; Based on the identified type of leaked oil, the source of the leak is determined. Wherein, the measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i and each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determining the similarity S between the measured spectrum and each of the feature spectra includes: The n measurement regions E in the measurement spectrum xi The measurement area is divided into m groups, and based on each measurement area E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj Where m is a positive integer, 1≤m≤n, 1≤j≤m; Determine the measurement region group G for each group after interference removal. xj The average measurement signal intensity x of all measured chromatographic peaks j ; The n control regions E in each of the aforementioned feature maps yi The region was divided into m control regions, and based on each control region E... yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj ; Determine the interference-free control region group G for each group. yj The average standard signal intensity y of all reference chromatographic peaks j ; Based on each group of interference-free measurement regions G xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks j Determine the similarity S between the measured spectrum and each of the characteristic spectra. m .

2. The method according to claim 1, characterized in that, The preset time interval is 0.02 to 0.5 seconds, and n is an integer from 4800 to 120000.

3. The method according to claim 1, characterized in that, m is an integer from 20 to 200, and each group of measurement regions includes 250 to 1000 measurement regions E. xi Each control region group includes 250 to 1000 control regions E. yi And in each group of measurement areas, measurement area E xi The number of control regions E in each control region group yi The number of them is the same.

4. The method according to claim 1, characterized in that, The measurement based on each of the measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i For each measurement region E in each measurement region group xi After interference removal processing, the measurement regions G are obtained after interference removal. xj ,include: Based on n measurement regions E xi The measured signal intensity x of all measured chromatographic peaks i Determine the n measurement regions E xi The maximum measured signal intensity x max and minimum measured signal intensity x min ; Determine the intensity x of each measured signal i With the minimum measured signal intensity x min The difference is used to obtain the measurement region E of each region. xi The corrected measurement signal intensity x for all measured chromatographic peaks i校 ; The calibrated measurement signal intensity x in each measurement area group i校 Less than (x) max -x min The measurement regions with a ratio of 5 ≤ a ≤ 10 are discarded as interference regions, resulting in the interference-free measurement region groups G. xj ; The basis for each of the control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i For each control region E in each control region group yi After interference removal processing, the interference-removed control region groups G were obtained. yj ,include: Based on n control regions E yi The standard signal intensity y of all reference chromatographic peaks within the range i Determine the n control regions E yi The maximum standard signal strength y in max and minimum standard signal strength y min ; Determine the signal strength y of each standard i With the minimum standard signal strength y min The difference is used to obtain the control regions E. yi Correction standard signal intensity y of all reference chromatographic peaks i校 ; The calibration standard signal intensity y in each control region group i校 Less than (y) max -y min The control regions with a ratio of 5 ≤ a ≤ 10 are discarded as interference regions, resulting in the interference-free control region groups G. yj .

5. The method according to claim 1, characterized in that, Based on each group of interference-free measurement regions G xj The average measurement signal intensity x of all measured chromatographic peaks j and the control region group G after interference removal for each group yj The average standard signal intensity y of all reference chromatographic peaks j The similarity S between the measured spectrum and each of the characteristic spectra is calculated according to the following formula. m : Where m represents the measurement region group G in the measurement spectrum after interference removal. xj The number or the interference-free control region group G in each of the aforementioned feature maps yj The number of each measurement region group G after interference removal, j represents the number of each measurement region group G after interference removal. xj The serial number or each interference-free control region group G yj The serial number.

6. The method according to claim 1, characterized in that, The method also includes: Obtain a characteristic spectrum of at least one preset oil; wherein the test conditions for obtaining the characteristic spectrum are the same as the test conditions for obtaining the determination spectrum.

7. The method according to claim 6, characterized in that, The method also includes: Acquire the characteristic spectra of all oils that may leak into the water, and establish a characteristic spectra library including the characteristic spectra of all the oils. Determining the similarity S between the measured spectra of the tested sample and the characteristic spectra of at least one preset oil includes: Determine the similarity S between the measured spectrum of the test sample and each of the feature spectra in the feature spectrum library.

8. The method according to any one of claims 1 to 7, characterized in that, The step of determining the type of leaked oil in the water sample to be tested based on the similarity S includes: The similarity S between the measured spectrum and each of the feature spectra is determined sequentially, and the preset oil type corresponding to the feature spectrum with the largest similarity S value and greater than 0.99 is determined as the leaked oil type in the water sample to be tested.

9. The method according to any one of claims 1 to 7, characterized in that, The separation of the oil phase from the water sample to be tested includes: The water sample to be tested is subjected to solid-phase microextraction, wherein the solid-phase microextraction includes direct extraction and / or headspace extraction.

10. The method according to claim 9, characterized in that, The conditions for direct extraction include: direct extraction time of 1–20 min, direct extraction temperature of 25–60 °C, desorption time of 0.5–5 min, and desorption temperature of 250–280 °C. The headspace extraction conditions include: headspace extraction time of 5–20 min, headspace extraction temperature of 30–70 °C, desorption time of 0.5–5 min, and desorption temperature of 250–280 °C.

11. The method according to any one of claims 1 to 7, characterized in that, The chromatographic analysis is gas chromatography, and the operating conditions for the gas chromatography analysis include: FID detector, splitless injection, injection volume of 0.1–2.0 μl, carrier gas of helium, chromatographic column of 5 m × 530 μm × 0.15 μm high-temperature stainless steel capillary column, sampling frequency of 2–50 Hz, constant flow rate of 1–25 mL / min, initial temperature of 35–120 °C, heating rate of 2–20 °C / min, final temperature of 250–430 °C, and holding time of 5–15 min.

12. The method according to any one of claims 1 to 7, characterized in that, In the water sample to be tested, the concentration of the oil phase is 1 mg / L to 100 mg / L.

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