Method for detecting content of petroleum hydrocarbon in biological waste residues

Abstract

The invention relates to a method for detecting the content of petroleum hydrocarbon in biological waste residues, which comprises the following steps: firstly obtaining a cell substrate, then measuring the absorption peak of the cell substrate, marking the area of a first peak appearing near 9.2 THz as F1, marking the area of a second peak appearing near 10.6 THz as F2, and marking the peak intensity of an absorption peak appearing near 17.3 THz as f3; then measuring the absorption peak of the biological waste residue, marking the area of a first peak appearing near 8.9 THz as G1, marking the area of a second peak appearing near 16.5 THz as G2, and marking the peak intensity of the absorption peak of the second peak as g3; the peak intensity of an absorption peak appearing at 5.9 THz is marked as b1; the peak intensity of an absorption peak appearing at 11.9 THz is marked as b2; and finally, substituting the detected data into a formula, and calculating to obtain the content of petroleum hydrocarbon in the biological waste residues. The petroleum hydrocarbon content% (w / w) is equal to (G1-F base material)-a * (g3-(b1 + b2) / 2); wherein F base material is equal to g3 * (F1 + F2) / f3, a is a coefficient, and the value range of a is 0.2-0.25. The method is accurate and reliable in detection result, and effectively solves the problem of detection deviation in an existing detection method.

Description

Technical Field

[0001] The invention belongs to the field of environmental detection, and relates to a method for detecting the content of petroleum hydrocarbons in biological waste residues generated after biological treatment of oily waste gas or oily waste liquid. Background Art

[0002] Petroleum hydrocarbons are a class of organic compounds that are widely present in the environment and are widely used as additives in the coatings industry. However, petroleum hydrocarbons are also common pollutants that pose a threat to the environment and human health.

[0003] Biological treatment is an emerging technology that uses microorganisms to treat oily waste gas or oily waste liquid, including biofiltration, biotrickling, biowashing, activated sludge and membrane bioprocess. The purpose of biological treatment is to convert pollutants including petroleum hydrocarbons into harmless or low-toxic substances, including esters, proteins, carbohydrates, etc. The solid matter produced after biological treatment is referred to as biological waste residue, which includes bacteria that died during the treatment process and substances converted into solids during the treatment process.

[0004] At present, the metabolic mechanism of microbial degradation of petroleum hydrocarbons is the focus of research, such as Figure 1 As shown in the figure, after the waste liquid containing organic pollutants (petroleum hydrocarbons, organic solvents, resins, VOCs, etc.) enters the reaction tank, it is effectively captured by the microorganisms used for biological treatment. The solid matter produced after the microorganisms in the water tank debond, disperse and metabolize the pollutants under an aerobic environment is the biological waste residue; this process is mainly a biological assimilation and biological metabolism process under aerobic conditions. Part of the organic pollutants are converted into proteins, peptides, sugars and other substances by microbial assimilation, forming the microbial body and its secondary metabolites, which are used to maintain the stability of microbial life and population in the reaction tank; the other part is converted into carbon dioxide and water by microbial energy metabolism. The inorganic components contained in the pollutants are not metabolized by microorganisms, and become one of the components of biological waste residue through flocculation. Understanding these metabolic pathways will help develop more effective biological treatment methods and improve the degradation efficiency of petroleum hydrocarbons. If the biological waste residue obtained by biological treatment meets the emission standards, it can be directly landfilled or incinerated; if it does not meet the emission standards, it will cost money for secondary treatment.

[0005] According to Appendix O of the "Identification Standard for Hazardous Wastes - Identification of Toxic Substance Content" (GB 5085.6-2007), the total amount of recoverable petroleum hydrocarbons in solid waste is determined by infrared spectroscopy. Infrared spectroscopy is a rapid, non-destructive analytical technique that can provide information about the chemical composition of the sample.

[0006] In order to confirm the safety of biological waste residues produced after biological treatment of oily wastewater, the applicant of the present invention conducted a series of experiments. During the experiments, it was found that it was difficult to obtain accurate results for the detection of petroleum hydrocarbon content in biological waste residues using the infrared spectroscopy method recorded in GB 5085.6-2007. The same batch of biological waste residues was tested for petroleum hydrocarbon content multiple times according to the method recorded in GB 5085.6-2007, and the difference in the test results reached more than 3 times (ranging from 1.33% to 7.81% w / w).

[0007] In order to accurately determine the content of petroleum hydrocarbons in solid waste residues, a more precise analytical method is needed. Gas chromatography-mass spectrometry (GC-MS) is an advanced technology that can provide high-resolution and high-sensitivity analysis, and has also been used to determine the lipid content of algae cells (Article No.: 1672-5174 (2012) 05-035-06). GC-MS can separate and identify complex organic compounds, including petroleum hydrocarbons and their metabolites. Through GC-MS analysis, the content of petroleum hydrocarbons in solid waste residues can be more accurately determined, and the detection value of infrared spectroscopy can be corrected. However, the use of gas chromatography-mass spectrometry for the detection of petroleum hydrocarbon content in biological waste residues has not yet achieved satisfactory results in terms of detection efficiency and accuracy.

[0008] It can be seen that biological treatment of oily waste gas or oily waste liquid is an emerging technology, and there is a technical gap in the rapid detection of the content of petroleum hydrocarbons in the biological waste residues produced by the biological treatment of oily waste gas or oily waste liquid. Summary of the invention

[0009] In order to solve the technical problem of inaccurate detection methods of petroleum hydrocarbon content in biological waste residues, the inventors of the present application studied the degradation mechanism of petroleum hydrocarbons and found that the oil components produced during the life process of fungi may interfere with the detection results of infrared spectroscopy, resulting in inaccurate detection results; based on this finding, the present invention provides a new method for detecting the petroleum hydrocarbon content in biological waste residues, which has accurate and reliable detection results and effectively solves the detection deviation problem existing in existing detection methods.

[0010] To achieve the above object, the present invention adopts the following technical solution:

[0011] A method for detecting the content of petroleum hydrocarbons in biological waste residues, the method comprising the following steps:

[0012] Step S1: obtaining a cell substrate;

[0013] Inoculate the microorganisms used for biotreatment in a synthetic medium containing glucose, maintain shaking and ventilation, and continue culturing until a biofilm or precipitation is produced. After the biofilm or precipitation is observed, continue culturing for 2-3 days, then filter out the liquid phase, and freeze-dry the solid phase to obtain a cell substrate;

[0014] Step S2: measuring the absorption peak of the cell substrate;

[0015] The freeze-dried cell substrate is placed on the stage of a Fourier transform far-infrared spectrometer to obtain a spectrum curve of the cell substrate; in the spectrum curve of the cell substrate, the first peak area appearing near 9.2 THz is marked as F1, the second peak area appearing near 10.6 THz is marked as F2, and the absorption peak intensity appearing near 17.3 THz is marked as f3;

[0016] Step S3: measuring the absorption peak of the biological waste residue;

[0017] After freeze-drying the biological waste residue obtained in the production, the detection is carried out according to the method described in step S2 to obtain the spectrum curve of the biological waste residue, and the first peak area appearing near 8.9THz is marked as G1, the starting point and the end point of the first peak area appear at 5.9THz and 11.9THz respectively, and the spectrum band of G1 covers the frequency bands of F1 and F2 peaks; the second peak area appearing near 16.5THz is marked as G2, which coincides with the f3 peak frequency band, and the absorption peak intensity of the second peak is marked as g3; the absorption peak intensity appearing at 5.9THz is recorded as b1; the absorption peak intensity appearing at 11.9THz is recorded as b2; then the data obtained by the detection is substituted into the following formula to calculate the content of petroleum hydrocarbons in the biological waste residue;

[0018] Petroleum hydrocarbon content % (w / w) = (G1-F substrate)-a×(g3-(b1+b2) / 2);

[0019] Among them, F substrate = g3×(F1+F2) / f3, a is a coefficient, and the value range is 0.2-0.25.

[0020] As a preferred embodiment of the present invention, in step S1, the microorganism used for biological treatment is Brevimonas.

[0021] As a preferred embodiment of the present invention, in step S1, the preparation method of the synthetic culture medium containing glucose is: 0.4g glucose, 0.7g dipotassium hydrogen phosphate, 0.3g potassium dihydrogen phosphate, 0.05g sodium citrate, 0.01g MgSO4·7H2O, and 0.1g ammonium sulfate are added to 100mL pure water in sequence; after fully dissolving and mixing, sterilize and cool to room temperature for use.

[0022] As a preferred embodiment of the present invention, in step S1, the inoculated synthetic culture medium is continuously shaken at 30°C and 180r / min to maintain ventilation; when the formation of a biofilm or precipitation is observed, the culture is continued for 3 days, the liquid phase is filtered out, the solid phase material is freeze-dried after washing with pure water, and the cell substrate is obtained.

[0023] As a preferred embodiment of the present invention, in step S2, the freeze-dried cell substrate is first placed on a hollow sample rack and evenly pressed into a sheet with a thickness not exceeding 20 microns, and then infrared detection is performed, and the obtained terahertz spectrum original information is subjected to baseline correction and denoising and smoothing processing in sequence to obtain a spectral curve of the cell substrate; wherein the model of the Fourier transform far-infrared spectrometer is Bruker IFS 66v / S.

[0024] As a preferred embodiment of the present invention, in step S3, the biological waste residue is first placed on a hollow sample rack and evenly pressed into a sheet with a thickness not exceeding 20 microns, and then placed on the stage of a Fourier transform far-infrared spectrometer for infrared detection, and the obtained terahertz spectrum original information is subjected to baseline correction and denoising and smoothing processing in turn to obtain a spectral curve of the biological waste residue.

[0025] As a preferred embodiment of the present invention, if the content of petroleum hydrocarbons in the biological waste residue exceeds 8%, the freeze-dried biological waste residue is mixed with the freeze-dried cell substrate in a certain mass ratio to reduce the content of petroleum hydrocarbons in the biological waste residue before detection; and the accurate content of petroleum hydrocarbons in the biological waste residue is calculated based on the proportion of the biological waste residue in the mixture and the calculation formula of the petroleum hydrocarbon content to obtain.

[0026] As a preferred embodiment of the present invention, in step S3, the method for determining the coefficient a comprises the following steps:

[0027] (1) adding a certain amount of petroleum hydrocarbon to the cell substrate to simulate biological waste residue containing petroleum hydrocarbon, and obtaining spectral curves of cell substrate samples with different contents of petroleum hydrocarbon according to the method described in step S2, marking the first peak area appearing near 8.9 THz in the spectral curve of the petroleum hydrocarbon cell substrate sample as G1, the starting point and the end point of the first peak area appear at 5.9 THz and 11.9 THz respectively, and the spectral frequency band of G1 covers the frequency bands of F1 and F2 peaks; marking the second peak area appearing near 16.5 THz as G2, and the absorption peak intensity of the second peak overlapping with the f3 peak frequency band is marked as g3; the absorption peak intensity appearing at 5.9 THz is recorded as b1; and the absorption peak intensity appearing at 11.9 THz is recorded as b2;

[0028] (2) The contribution of the oil components contained in the microorganisms used for biological treatment to the absorption peak G1 is calculated by comparing the ratio of the sum of the absorption peak areas F1 and F2 of the cell substrate at the first peak and the second peak to f3 with the absorption peak area g3 of the petroleum hydrocarbon cell substrate sample at the second peak. The calculation formula is:

[0029] F substrate = g3 × (F1 + F2) / f3 (I)

[0030] Calculate the value of coefficient a in formula (II) based on the obtained data;

[0031] a=(G1-F substrate-petroleum hydrocarbon content %) / (g3-(b1+b2) / 2)(Ⅱ).

[0032] As a further preferred embodiment of the present invention, Unscrambler software is used to perform baseline correction processing on the original terahertz spectrum information, and a convolution smoothing method is used to perform denoising and smoothing processing on the original terahertz spectrum information.

[0033] Advantages and beneficial effects of the present invention:

[0034] (1) The detection method provided by the present invention can quickly detect the content of free petroleum hydrocarbons in biological waste residues without complicated pretreatment, and can provide fast real-time detection for biological waste treatment processes with high accuracy. When the water content in the sample does not exceed 4%, it will not affect the accuracy of the detection result.

[0035] (2) The detection method provided by the present invention fully considers the influence of the oil components produced during the life process of fungi on infrared spectroscopy detection, and effectively solves the detection deviation problem existing in the existing detection methods.

[0036] (3) The detection method provided by the present invention can quickly complete the detection of the petroleum hydrocarbon content in biological waste residue, which is beneficial for operators to adjust process parameters in real time according to the monitoring results and reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easy to understand. In the accompanying drawings:

[0038] Figure 1 Schematic diagram of the microbial decomposition of organic pollutants used in biological treatment.

[0039] Figure 2 Schematic diagram of the far-infrared spectrum curve of the cell substrate of the present invention; wherein the abscissa is the frequency (THz) and the ordinate is the absorbance (AU).

[0040] Figure 3 It is a schematic diagram of the far-infrared spectrum curve of the cell substrate of the present invention with petroleum hydrocarbons (simulated biological waste residue) added thereto; wherein the abscissa is the frequency (THz) and the ordinate is the absorbance (AU). DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solutions and advantages of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The model of the Fourier transform far infrared spectrometer used in the following examples is Bruker IFS 66v / S.

[0043] The Unscrambler software used in the following examples was from CAMO AS, Oslo, Norway.

[0044] The microorganism used in the following examples is Brachymonas sp., which is provided by Botai (Shanghai) Biotechnology Co., Ltd.

[0045] The preparation method of the synthetic medium containing glucose used in the following examples is as follows: 0.4 g of glucose, 0.7 g of dipotassium hydrogen phosphate (K2HPO4), 0.3 g of potassium dihydrogen phosphate (KH2PO4), 0.05 g of sodium citrate (Na3C6H5O7), 0.01 g of magnesium sulfate 7hydrate (MgSO4·7H2O), and 0.1 g of ammonium sulfate ((NH4)2SO4) are added to 100 mL of pure water in sequence; after fully dissolving and mixing, the mixture is sterilized at conventional high temperature (1.1 atmospheres, 121°C for 20 min), and cooled to room temperature for use.

[0046] Example 1

[0047] Step S1: obtaining a cell substrate;

[0048] Take 100 mL of synthetic culture medium containing glucose, add 3 colonies of Bacillus brevis through an inoculation loop (the bacterial species must be exactly the same as the species actually used in production); continuously shake the inoculated culture medium at 30°C and 180 r / min, and keep it ventilated; continue to culture for 0-3 days after the formation of biofilm or precipitation is observed; filter out the liquid phase, rinse with pure water 3 times, and then freeze-dry the solid phase to obtain the cell substrate.

[0049] Step S2: measuring the absorption peak of the cell substrate;

[0050] The cell substrate was placed on a hollow sample holder and pressed evenly to a thickness of no more than 20 microns. The substrate was then placed on the stage of a Fourier transform infrared spectrometer. The Fourier transform infrared spectrometer parameters were set to a resolution of 0.06 THz (2 cm -1), the number of scans was 128 times, and the measurement range of the Fourier transform spectrometer was 2-20 THz. The Unscrambler software was used to perform baseline correction on the original information of the terahertz spectrum, and the convolution smoothing method was used to perform denoising and smoothing on the original information of the terahertz spectrum to obtain the spectral curve of the cell substrate.

[0051] Take the spectrum curve of Day 3 (such as Figure 2 Taking the absorption peak of Day 0 to Day 3 as an example, the first peak area appearing near 9.2 THz is marked as F1; the second peak area appearing near 10.6 THz is marked as F2; ​​the absorption peak intensity appearing near 17.3 THz is marked as f3; record F1, F2 and f3 of each sample from Day 0 to Day 3, and the results are shown in Table 1:

[0052] Table 1 Test results of cell substrates at different culture days

[0053] Day 0 Day 1 Day 2 Day 3 F1 1.13 1.38 1.59 1.63 F2 0.89 1.89 2.06 1.95 f3 15.31 16.52 15.06 15.85

[0054] The experimental results show that when the biofilm or precipitation just appears, the amount of oil contained in the bacteria is not yet stable. After 2-3 days of continuous cultivation, due to the death of some bacteria and other reasons, the oil content of the obtained cell substrate is relatively stable and suitable for reference. In view of the fact that in actual production, the biological waste residue contains mainly dead bacteria and bacterial metabolites, the data of Day 3 is taken as the reference value in this embodiment and is included in the calculation of the following steps.

[0055] Step S3: adding petroleum hydrocarbons to the cell substrate to simulate biological waste residues containing petroleum hydrocarbons, and measuring the absorption peak of the cell substrate containing petroleum hydrocarbons;

[0056] Specifically, step S3 includes the following steps:

[0057] Step S31: preparing a petroleum hydrocarbon sample;

[0058] Accurately weigh 15.0 ml of n-hexane, 15.0 ml of isooctane and 10.0 ml of chlorobenzene, and add them into a 50 ml sealed bottle; cover the bottle stopper tightly to avoid loss by evaporation; and store at 4°C for future use.

[0059] Step S32: accurately weigh 99 mg of freeze-dried cell substrate, add 1 mg of petroleum hydrocarbon sample, mix thoroughly, and obtain a sample containing 1% petroleum hydrocarbon; prepare samples containing 2%, 4% and 8% petroleum hydrocarbon respectively in the same way.

[0060] Step S33: testing the absorption peaks of the four samples respectively;

[0061] The sample was placed on a hollow sample holder and pressed evenly to a thickness of no more than 20 microns. The sample was then placed on the stage of a Fourier transform infrared spectrometer. The Fourier transform infrared spectrometer parameters were set to a resolution of 0.06 THz (2 cm-1 ), the number of scans was 128 times, and the measurement range of the Fourier transform spectrometer was 2-20 THz. The Unscrambler software was used to perform baseline correction on the original information of the terahertz spectrum, and the convolution smoothing method was used to perform denoising and smoothing on the original information of the terahertz spectrum to obtain the spectral curve of the sample.

[0062] Take the spectrum curve of sample 4 (such as Figure 3 Take the sample as an example; the first peak of the sample appears near 8.9 THz, the starting point and end point of the first peak area appear at 5.9 THz and 11.9 THz respectively, the spectrum band covers the frequency bands of F1 and F2 peaks, and its area is recorded as G1. The second peak of the sample appears near 16.5 THz (coinciding with the f3 peak frequency band), its area is recorded as G2, and the absorption peak intensity of the second peak is recorded as g3; the absorption peak intensity of 5.9 THz is recorded as b1; the absorption peak intensity of 11.9 THz is recorded as b2.

[0063] To avoid accidental errors, each sample was tested 3 times and the average value of the 3 times was recorded in Table 2.

[0064] Table 2 Test results of samples with different contents of petroleum hydrocarbons

[0065] Sample 1 Sample 2 Sample 3 Sample 4 Petroleum hydrocarbon content 1％ 2％ 4％ 8％ G1 8.12 9.32 11.86 15.48 g3 16.8 17.2 18.1 17.8 b1 1.75 1.89 1.96 1.92 b2 1.99 2.01 2.33 2.32

[0066] Step S4: Calculate F base material according to the following formula (I):

[0067] F substrate = g3 × (F1 + F2) / f3 (I)

[0068] Based on the data of Day 3 in Table 1, the contribution of the oil components contained in the microorganisms used for biological treatment to the absorption peak G1 was calculated by using the ratio of the sum of the absorption peak areas F1 and F2 of the cell substrate at the first peak and the second peak to f3, compared with the absorption peak intensity g3 of the sample at the second peak;

[0069] According to the data in Table 2, the value of coefficient a in formula (II) is calculated:

[0070] a=(G1-F base material-petroleum hydrocarbon content%) / (g3-(b1+b2) / 2) (Ⅱ)

[0071] The calculation results of the a values ​​of the four samples with different petroleum hydrocarbon contents are shown in Table 3, and the average a value is 0.2262.

[0072] Table 3 a value calculated based on samples with different petroleum hydrocarbon contents

[0073] Sample 1 Sample 2 Sample 3 Sample 4 Petroleum hydrocarbon content 1％ 2％ 4％ 8％ Calculate the value of a 0.22273 0.22525 0.23640 0.22064

[0074] Step S5: freeze-drying the biological waste residue obtained in the production and then testing it according to the following method;

[0075] The biowaste sample was placed on a hollow sample holder and pressed evenly into a sheet with a thickness of no more than 20 microns. The sheet was then placed on the stage of a Fourier transform infrared spectrometer. The Fourier transform infrared spectrometer parameters were set to a resolution of 0.06 THz (2 cm -1 ), the number of scans was 128 times, and the measurement range of the Fourier transform spectrometer was 2-20 THz. The Unscrambler software was used to perform baseline correction on the original information of the terahertz spectrum, and the convolution smoothing method was used to perform denoising and smoothing on the original information of the terahertz spectrum to obtain the spectral curve of the sample.

[0076] The first peak of the sample appears near 8.9 THz, and its area is recorded as G1; the second peak of the sample appears near 16.5 THz (coinciding with the f3 peak frequency band), and the absorption peak intensity of the second peak is recorded as g3; the absorption peak intensity of 5.9 THz is recorded as b1; and the absorption peak intensity of 11.9 THz is recorded as b2.

[0077] Substitute the data obtained from the test and the a value obtained by the above calculation into the following formula to calculate the content of petroleum hydrocarbons in the sample.

[0078] Petroleum hydrocarbon content % (w / w) = (G1-F base material)-a×(g3-(b1+b2) / 2)(Ⅲ)

[0079] Wherein, F substrate = g3×(F1+F2) / f3.

[0080] Example 2

[0081] Steps S1 to S4 are the same as in Example 1;

[0082] The specific steps of step S5 are: freeze-drying the biological waste residue obtained in the production and then testing it according to the following method.

[0083] The biological waste residue and the biological substrate were uniformly mixed in a mass ratio of 1:1, and then the mixed sample was placed on a hollow sample rack and pressed into a sheet uniformly, with a thickness of no more than 20 microns; then placed on the stage of the Fourier transform far-infrared spectrometer; the Fourier transform far-infrared spectrometer parameters were set to a resolution of 0.06THz (2cm -1 ), the number of scans was 128 times, and the measurement range of the Fourier transform spectrometer was 2-20 THz. The Unscrambler software was used to perform baseline correction on the original information of the terahertz spectrum, and the convolution smoothing method was used to perform denoising and smoothing on the original information of the terahertz spectrum to obtain the spectral curve of the sample.

[0084] The first peak of the sample appears near 8.9 THz, and its area is recorded as G1; the second peak of the sample appears near 16.5 THz (coinciding with the f3 peak frequency band); the absorption peak intensity of the second peak is recorded as g3; the absorption peak intensity of 5.9 THz is recorded as b1; and the absorption peak intensity of 11.9 THz is recorded as b2.

[0085] Substitute the data obtained from the test and the a value obtained by the above calculation into the following formula to calculate the content of petroleum hydrocarbons in the sample.

[0086] Petroleum hydrocarbon content % (w / w) = [(G1-F base material)-a×(g3-(b1+b2) / 2)] / n(Ⅳ)

[0087] Wherein, n is the content of biological waste residue in the sample; in this embodiment, the content of biological waste residue in the sample is 50%, so n=50%.

[0088] Example 3

[0089] Step S1 and step S2 are the same as in Example 1;

[0090] Step S3 tests the absorption peaks of the four samples respectively, and the specific steps are as follows:

[0091] Step S31: preparing a petroleum hydrocarbon sample;

[0092] Accurately weigh 15.0 ml of n-hexane, 15.0 ml of isooctane and 10.0 ml of chlorobenzene, and add them to a 50 ml sealed bottle; cover the bottle stopper tightly to prevent volatile losses; accurately weigh 492 mg of freeze-dried cell substrate, add 8 mg of petroleum hydrocarbon sample, and mix thoroughly to obtain a sample containing 4% petroleum hydrocarbon.

[0093] Step S32: Take 100 mg of a sample containing 4% petroleum hydrocarbons, add 1 μl of pure water to obtain sample 1, add 2 μl of pure water to obtain sample 2, add 3 μl of pure water to obtain sample 3, and add 4 μl of pure water to obtain sample 4.

[0094] Step S33: testing the absorption peaks of the four samples obtained in step S32 respectively.

[0095] The sample was placed on a hollow sample holder and pressed evenly, and then placed on the stage of the Fourier transform far-infrared spectrometer; the Fourier transform far-infrared spectrometer parameters were set to a resolution of 0.06 THz (2 cm -1 ), the number of scans was 128 times, and the measurement range of the Fourier transform spectrometer was 2-20 THz. The Unscrambler software was used to perform baseline correction on the original information of the terahertz spectrum, and the convolution smoothing method was used to perform denoising and smoothing on the original information of the terahertz spectrum to obtain the spectral curve of the sample.

[0096] The first peak of the sample appears near 8.9 THz, and its area is recorded as G1; the second peak of the sample appears near 16.5 THz, and the absorption peak intensity is recorded as g3; the absorption peak intensity of 5.9 THz is recorded as b1; and the absorption peak intensity of 11.9 THz is recorded as b2.

[0097] Table 4 Test results of different water contents

[0098] Sample 1 Sample 2 Sample 3 Sample 4 Water addition 1 μl 2 μl 3 μl 4 μl G1 11.98 12.36 12.15 12.06 g3 18.1 18.5 18.3 18.6 b1 2.01 1.88 1.98 2.22 b2 2.32 2.25 2.18 2.63

[0099] From the analysis of the test results of different moisture contents, it can be seen that a slight change in moisture content has little effect on the test results. It can be seen that when the moisture content in the test sample does not exceed 4%, it will not affect the accuracy of the test results.

[0100] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art of the present invention, according to the idea of ​​the present invention, some simple deductions, deformations or substitutions can be made. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for detecting the content of petroleum hydrocarbons in biological waste residues, characterized in that: The method comprises the following steps: Step S1: obtaining a cell substrate; Inoculate the microorganisms used for biotreatment in a synthetic medium containing glucose, maintain shaking and ventilation, and continue culturing until a biofilm or precipitation is produced. After the biofilm or precipitation is observed, continue culturing for 2-3 days, then filter out the liquid phase, and freeze-dry the solid phase to obtain a cell substrate; Step S2: measuring the absorption peak of the cell substrate; The freeze-dried cell substrate is placed on the stage of a Fourier transform far-infrared spectrometer to obtain a spectrum curve of the cell substrate; in the spectrum curve of the cell substrate, the first peak area appearing near 9.2 THz is marked as F1, the second peak area appearing near 10.6 THz is marked as F2, and the absorption peak intensity appearing near 17.3 THz is marked as f3; Step S3: measuring the absorption peak of the biological waste residue; After freeze-drying the biological waste residue obtained in the production, the detection is carried out according to the method described in step S2 to obtain the spectrum curve of the biological waste residue, and the first peak area appearing near 8.9THz is marked as G1, the starting point and the end point of the first peak area appear at 5.9THz and 11.9THz respectively, and the spectrum band of G1 covers the frequency bands of F1 and F2 peaks; the second peak area appearing near 16.5THz is marked as G2, which coincides with the f3 peak frequency band, and the absorption peak intensity of the second peak is marked as g3; the absorption peak intensity appearing at 5.9THz is recorded as b1; the absorption peak intensity appearing at 11.9THz is recorded as b2; then the data obtained by the detection is substituted into the following formula to calculate the content of petroleum hydrocarbons in the biological waste residue; Petroleum hydrocarbon content % (w / w) = (G1-F substrate)-a×(g3-(b1+b2) / 2); Among them, F substrate = g3×(F1+F2) / f3, a is a coefficient, and the value range is 0.2-0.

25.

2. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S1, the microorganism used for biological treatment is Brevimonas.

3. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S1, the preparation method of the synthetic culture medium containing glucose is as follows: 0.4g glucose, 0.7g dipotassium hydrogen phosphate, 0.3g potassium dihydrogen phosphate, 0.05g sodium citrate, 0.01g MgSO4·7H2O, and 0.1g ammonium sulfate are added to 100mL pure water in sequence; after fully dissolving and mixing, the mixture is sterilized and cooled to room temperature for use.

4. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S1, the inoculated synthetic culture medium is continuously shaken at 30°C and 180r / min to maintain ventilation; when the formation of biofilm or precipitation is observed, the culture is continued for 3 days, the liquid phase is filtered out, the solid phase material is freeze-dried after washing with pure water, and the cell substrate is obtained.

5. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S2, the freeze-dried cell substrate is first placed on a hollow sample rack and evenly pressed into a sheet with a thickness not exceeding 20 microns, and then infrared detection is performed, and the obtained terahertz spectrum raw information is subjected to baseline correction and denoising and smoothing processing in sequence to obtain a spectral curve of the cell substrate; wherein the model of the Fourier transform far-infrared spectrometer is Bruker IFS 66v / S.

6. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S3, the biological waste residue is first placed on a hollow sample rack and evenly pressed into a sheet with a thickness not exceeding 20 microns, and then placed on the stage of a Fourier transform far-infrared spectrometer for infrared detection, and the obtained terahertz spectrum original information is subjected to baseline correction and denoising and smoothing processing in turn to obtain a spectral curve of the biological waste residue.

7. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: If the content of petroleum hydrocarbons in the biological waste residue exceeds 8%, the freeze-dried biological waste residue is mixed with the freeze-dried cell substrate in a certain mass ratio to reduce the content of petroleum hydrocarbons in the biological waste residue before testing; and the accurate content of petroleum hydrocarbons in the biological waste residue is calculated based on the proportion of the biological waste residue in the mixture and the calculation formula of the petroleum hydrocarbon content.

8. The method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 1, characterized in that: In step S3, the method for determining the coefficient a includes the following steps: (1) adding a certain amount of petroleum hydrocarbon to the cell substrate to simulate biological waste residue containing petroleum hydrocarbon, and obtaining spectral curves of cell substrate samples with different contents of petroleum hydrocarbon according to the method described in step S2, marking the first peak area appearing near 8.9 THz in the spectral curve of the petroleum hydrocarbon cell substrate sample as G1, the starting point and the end point of the first peak area appear at 5.9 THz and 11.9 THz respectively, and the spectral frequency band of G1 covers the frequency bands of F1 and F2 peaks; marking the second peak area appearing near 16.5 THz as G2, and the absorption peak intensity of the second peak overlapping with the f3 peak frequency band is marked as g3; the absorption peak intensity appearing at 5.9 THz is recorded as b1; and the absorption peak intensity appearing at 11.9 THz is recorded as b2; (2) The contribution of the oil components contained in the microorganisms used for biological treatment to the absorption peak G1 is calculated by comparing the ratio of the sum of the absorption peak areas F1 and F2 of the cell substrate at the first peak and the second peak to f3 with the absorption peak area g3 of the petroleum hydrocarbon cell substrate sample at the second peak. The calculation formula is: F substrate = g3 × (F1 + F2) / f3 (I) Calculate the value of coefficient a in formula (II) based on the obtained data; a=(G1-F substrate-petroleum hydrocarbon content %) / (g3-(b1+b2) / 2)(Ⅱ).

9. A method for detecting the content of petroleum hydrocarbons in biological waste residue according to claim 5 or 6, characterized in that: Unscrambler software was used to perform baseline correction on the original terahertz spectrum information, and convolution smoothing method was used to perform denoising and smoothing on the original terahertz spectrum information.

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