Dioxin detection method and system for waste incineration

Abstract

The invention discloses a dioxin detection method and system for waste incineration. The method comprises the following steps: collecting a flue gas sample of a waste incineration plant, pretreating the flue gas sample, transmitting the concentrated sample to a high-resolution gas chromatograph for separation, and detecting the separated dioxin homologues through a high-resolution mass spectrum. Comprehensively analyzing the retardation rate of the dioxin, the influence coefficient of the carrier gas entering the chromatographic column on the detection precision of the dioxin and the influence coefficient of the sample purification treatment on the detection precision of the dioxin to obtain an evaluation coefficient of the detection precision of the dioxin. According to the method, the dioxin detection precision evaluation coefficient is compared with the dioxin detection precision evaluation threshold value, so that the detection method is finally optimized according to the threshold value comparison result, and the effect of improving the accuracy of the dioxin detection method for waste incineration is achieved; the problem that in the prior art, a dioxin detection method for waste incineration is insufficient in accuracy is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of dioxin content detection, and in particular to a dioxin detection method and system for garbage incineration. Background Art

[0002] With the increasing awareness of environmental protection and the improvement of emission standards, the demand for efficient and accurate dioxin detection and control technologies is increasing. Research on the dioxin generation mechanism, emission patterns and in-depth control technology during waste incineration is also a top priority. These studies will help provide theoretical support and technical guidance for dioxin emission control in waste incineration plants.

[0003] Existing methods based on tunable laser spectroscopy combined with time-of-flight mass spectrometry involve excitation of molecules in the flue gas by a laser. These molecules then enter a time-of-flight mass spectrometer, where they are ionized and accelerated. Different molecules are then distinguished based on their flight times to the detector. This is achieved by varying the flight times of different molecules due to their varying mass and charge ratios.

[0004] For example, the invention patent publication number CN102062762B discloses a method for rapidly pre-treating soil samples for dioxin detection. The method includes: uniformly mixing the soil sample with aluminum oxide and copper powder in a mass ratio of 5:5:1; transferring the mixture to the extraction cell of an accelerated solvent extractor, adding a dioxin extraction standard and a purification standard, and then using a mixed solution of dichloromethane and n-hexane as the solvent; concentrating the sample, then purifying it on an acid-base silica gel column, concentrating it again, and transferring it to a sample vial with an insert, blowing it gently with nitrogen to approximately 20 μl; and then adding 1000 pg of dioxin to the sample before high-resolution chromatograph-mass spectrometry (HRMS). Compared to existing sample pre-treatment methods, this method is not suitable for conventional sample pre-treatment.

[0005] For example, the invention patent publication number CN103399002B discloses a method for rapid detection of trace dioxins, including preparing a SERS substrate for detection using methyl cellulose, sodium citrate, and silver ammonia solution as raw materials. Dioxin solutions of varying concentrations are mixed with the substrate, centrifuged, and tested using a laser Raman spectrometer to obtain a SERS spectrum of the dioxin. The relationship between the dioxin Raman spectrum absorption intensity at a certain wavenumber and the dioxin concentration is obtained, and a mathematical relationship between the Raman spectrum absorption intensity and the dioxin concentration is established. A dioxin solution of unknown concentration is tested using a laser Raman spectrometer, and the dioxin concentration is inferred based on the mathematical relationship between the dioxin Raman spectrum absorption intensity at a certain wavenumber and the dioxin concentration.

[0006] However, in the process of implementing the technical solutions of the embodiments of the present application, the present application discovered that the above technology has at least the following technical problems:

[0007] In the prior art, no effective dioxin blocking technology is used during the waste incineration process, and the sample processing is not sufficient, resulting in the problem of insufficient accuracy of the dioxin detection method used for waste incineration. Summary of the Invention

[0008] The embodiments of the present application provide a dioxin detection method and system for waste incineration, thereby solving the problem of insufficient accuracy of dioxin detection methods for waste incineration in the prior art and achieving the effect of improving the accuracy of dioxin detection methods for waste incineration.

[0009] The embodiment of the present application provides a dioxin detection method for waste incineration, comprising the following steps: collecting flue gas samples from a waste incineration plant, pre-treating the flue gas samples to remove interferences to obtain a pre-treated sample, concentrating the pre-treated sample by rotary evaporation to obtain a concentrated sample; transferring the concentrated sample to a high-resolution gas chromatograph for separation, and then detecting the separated dioxin homologues by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time; collecting the dioxin blocking rate, the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, analyzing the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, obtaining the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy, and the purification efficiency, The contamination rate of polychlorinated biphenyls (PCBs) and the sample processing time were analyzed to obtain the influence coefficient of sample purification on dioxin detection accuracy. A comprehensive analysis was conducted on the dioxin blockage rate, the influence coefficient of carrier gas entering the chromatographic column on dioxin detection accuracy, and the influence coefficient of sample purification on dioxin detection accuracy to obtain the dioxin detection accuracy assessment coefficient. The threshold of the influence of sample processing on dioxin detection accuracy and the dioxin detection accuracy assessment threshold were directly obtained through the database. The influence coefficient of sample purification on dioxin detection accuracy was compared with the threshold of the influence of sample processing on dioxin detection accuracy. The detection method was preliminarily optimized based on the threshold comparison results. The dioxin detection accuracy assessment coefficient was compared with the dioxin detection accuracy assessment threshold. The detection method was finally optimized based on the threshold comparison results.

[0010] Furthermore, the specific pretreatment process for pretreating the flue gas sample is as follows: taking out the glass fiber filter membrane with the flue gas sample from the sampler, dividing the glass fiber filter membrane into ten small pieces, and placing them into a cleaned extraction container, adding an organic solvent into the extraction container, using an ultrasonic extractor to extract to obtain an extract, performing liquid-liquid extraction on the extract, adding an extractant to remove moisture and polar substances, and obtaining a pretreated sample.

[0011] Furthermore, the specific concentration process of concentrating the pretreated sample by the rotary evaporation method is as follows: transferring the pretreated sample to a rotary evaporation container, concentrating the pretreated sample, reducing the volume of the solvent, obtaining a preliminary concentrated sample, replacing the solvent of the preliminary concentrated sample, and using the rotary evaporator again for final concentration to obtain a concentrated sample.

[0012] Furthermore, the specific separation process of transferring the concentrated sample to a high-resolution gas chromatograph for separation is as follows: the concentrated sample is transferred to an automatic injection vial, the automatic injection vial is placed in the automatic injector of the high-resolution gas chromatograph, the injection parameters are set, and the concentrated sample is heated at the injection port and carried by the carrier gas into the chromatographic column to obtain dioxin homologues.

[0013] Furthermore, the specific analysis process for analyzing the temperature, benzopyrene concentration and instrument response factor of the chromatographic column is as follows: collecting the temperature, benzopyrene concentration and instrument response factor of the chromatographic column, analyzing the temperature, benzopyrene concentration and instrument response factor of the chromatographic column, and obtaining the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy.

[0014] Furthermore, the specific analysis process for analyzing the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time is as follows: the dioxin homologues separated are detected by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time; the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time are analyzed to obtain the influence coefficient of sample purification treatment on the dioxin detection accuracy.

[0015] Furthermore, the specific comparison process of comparing the influence coefficient of sample purification treatment on the dioxin detection accuracy with the influence threshold of sample treatment on the dioxin detection accuracy is as follows: directly obtaining the influence threshold of sample treatment on the dioxin detection accuracy from the database, comparing the influence coefficient of sample purification treatment on the dioxin detection accuracy with the influence threshold of sample treatment on the dioxin detection accuracy; if the influence coefficient of sample purification treatment on the dioxin detection accuracy is greater than or equal to the influence threshold of sample treatment on the dioxin detection accuracy, preliminarily optimizing the dioxin detection method; if the influence coefficient of sample purification treatment on the dioxin detection accuracy is less than the influence threshold of sample treatment on the dioxin detection accuracy, marking the dioxin detection method as not affected by the sample treatment.

[0016] Furthermore, the specific comparison process of comparing the dioxin detection accuracy assessment coefficient with the dioxin detection accuracy assessment threshold is as follows: directly obtain the dioxin detection accuracy assessment threshold from the database, compare the dioxin detection accuracy assessment coefficient with the dioxin detection accuracy assessment threshold, if the dioxin detection accuracy assessment coefficient is less than the dioxin detection accuracy assessment threshold, finally optimize the dioxin detection method; if the dioxin detection accuracy assessment coefficient is greater than or equal to the dioxin detection accuracy assessment threshold, mark the dioxin detection method as good and no optimization is required.

[0017] Furthermore, the specific method for obtaining the dioxin detection accuracy evaluation coefficient is as follows: Where DAC represents the dioxin detection accuracy assessment coefficient, which is used to evaluate the accuracy of the dioxin detection method; XDR represents the influence coefficient of carrier gas entering the chromatographic column on the dioxin detection accuracy; FBG represents the influence coefficient of sample purification treatment on the dioxin detection accuracy; GYK represents the dioxin retardation rate; and e represents the natural constant.

[0018] The embodiment of the present application provides a dioxin detection system for waste incineration, which includes a sample collection module, a sample processing module, a data collection and analysis module, and a threshold comparison and optimization module: the sample collection module is used to collect flue gas samples from the waste incineration plant, pre-treat the flue gas samples, remove interferences, obtain pre-treated samples, and concentrate the pre-treated samples by rotary evaporation to obtain concentrated samples; the sample processing module is used to transfer the concentrated samples to a high-resolution gas chromatograph for separation, and then detect the separated dioxin homologues by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time; the data collection and analysis module is used to collect the dioxin blocking rate, the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, analyze the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, and obtain the carrier gas entering the chromatographic column. The influence coefficient of the column on the dioxin detection accuracy is analyzed by analyzing the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample and the sample processing time to obtain the influence coefficient of the sample purification treatment on the dioxin detection accuracy. A comprehensive analysis is conducted on the dioxin blocking rate, the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy and the influence coefficient of the sample purification treatment on the dioxin detection accuracy to obtain the dioxin detection accuracy evaluation coefficient; Threshold comparison and optimization module: used to directly obtain the threshold value of the influence of sample processing on the dioxin detection accuracy and the dioxin detection accuracy evaluation threshold through the database, compare the influence coefficient of the sample purification treatment on the dioxin detection accuracy with the threshold value of the influence of the sample processing on the dioxin detection accuracy, preliminarily optimize the detection method based on the threshold comparison results, compare the dioxin detection accuracy evaluation coefficient with the dioxin detection accuracy evaluation threshold, and finally optimize the detection method based on the threshold comparison results.

[0019] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0020] 1. By comparing the dioxin detection accuracy assessment coefficient with the dioxin detection accuracy assessment threshold, the detection method is ultimately optimized based on the threshold comparison results, thereby achieving the effect of improving the accuracy of the dioxin detection method for waste incineration, effectively solving the problem of insufficient accuracy of the dioxin detection method for waste incineration in the existing technology.

[0021] 2. By pre-treating the flue gas sample to remove interferences, the pre-treated sample is concentrated by rotary evaporation to obtain a concentrated sample, thereby achieving the effect of reducing the combustion time of the sample.

[0022] 3. By transferring the concentrated sample to a high-resolution gas chromatograph for separation, the separated dioxin homologues are detected using a high-resolution mass spectrometer, thereby improving the separation efficiency of the high-resolution gas chromatography. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Flowchart of the dioxin detection method for waste incineration provided in an embodiment of the present application;

[0024] Figure 2 An image showing the influence coefficient of sample purification on dioxin detection accuracy in the dioxin detection method for waste incineration provided in an embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of the structure of a dioxin detection system for waste incineration provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] The embodiments of the present application provide a dioxin detection method and system for waste incineration, thereby solving the problem of insufficient accuracy of dioxin detection methods for waste incineration in the prior art. By comparing the dioxin detection accuracy evaluation coefficient with the dioxin detection accuracy evaluation threshold, the detection method is ultimately optimized based on the threshold comparison result, thereby achieving the effect of improving the accuracy of the dioxin detection method for waste incineration.

[0027] The technical solution in the embodiments of the present application is to solve the problem of insufficient accuracy of the dioxin detection method for waste incineration. The overall idea is as follows:

[0028] Through systematic flue gas sample pretreatment, concentration, high-resolution gas chromatography separation and high-resolution mass spectrometry detection, combined with database analysis, we were able to obtain the accuracy assessment coefficient of dioxin detection in waste incineration plants, and then conduct preliminary and final optimization of the detection method, achieving the effect of improving the accuracy of dioxin detection methods used in waste incineration.

[0029] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0030] like Figure 1 As shown, it is a flow chart of a dioxin detection method for waste incineration provided by an embodiment of the present application. The method is applied to a dioxin detection system for waste incineration, and the method comprises the following steps: collecting flue gas samples from a waste incineration plant, pre-treating the flue gas samples to remove interferences to obtain a pre-treated sample, concentrating the pre-treated sample by rotary evaporation to obtain a concentrated sample; transmitting the concentrated sample to a high-resolution gas chromatograph for separation, and then detecting the separated dioxin homologues by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time; collecting the dioxin blockage rate, the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, analyzing the temperature, the benzopyrene concentration, and the instrument response factor of the chromatographic column to obtain the effect of the carrier gas entering the chromatographic column on the dioxin detection accuracy. The influence coefficient of sample purification treatment on dioxin detection accuracy was obtained by analyzing the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time. The influence coefficient of sample purification treatment on dioxin detection accuracy was obtained. The blocking rate of dioxins, the influence coefficient of carrier gas entering the chromatographic column on dioxin detection accuracy, and the influence coefficient of sample purification treatment on dioxin detection accuracy were comprehensively analyzed to obtain the dioxin detection accuracy evaluation coefficient. The influence threshold of sample processing on dioxin detection accuracy and the dioxin detection accuracy evaluation threshold were directly obtained through the database. The influence coefficient of sample purification treatment on dioxin detection accuracy was compared with the influence threshold of sample processing on dioxin detection accuracy. The detection method was preliminarily optimized based on the threshold comparison results. The dioxin detection accuracy evaluation coefficient was compared with the dioxin detection accuracy evaluation threshold. The detection method was finally optimized based on the threshold comparison results.

[0031] Furthermore, the specific pretreatment process for pretreating the flue gas sample is as follows: taking out the glass fiber filter membrane with the flue gas sample from the sampler, dividing the glass fiber filter membrane into ten small pieces, and placing them into a cleaned extraction container, adding an organic solvent into the extraction container, using an ultrasonic extractor to extract to obtain an extract, performing liquid-liquid extraction on the extract, adding an extractant to remove moisture and polar substances, and obtaining a pretreated sample.

[0032] In this embodiment, the flue gas sample should be processed as soon as possible after collection. If immediate processing is not possible, the sample should be stored in a low-temperature environment (usually below 4°C) to prevent decomposition or adsorption of dioxins. The glass fiber filter used to collect the flue gas is removed from the sampler, and the mechanical arm is raised to cut the filter into small pieces. The pieces are placed in a pre-cleaned extraction container. An appropriate amount of organic solvent (such as toluene, dichloromethane, etc.) is added to the extraction container containing the filter membrane fragments. Extraction is performed using an ultrasonic extractor. The extraction time is generally between 30 minutes and 1 hour to fully extract the dioxins on the filter membrane. The extract is filtered through filter paper to remove the filter membrane fragments and other solid impurities. Liquid-liquid extraction is performed, and sodium sulfate solution is added to remove moisture and polar substances. The extract is further purified using a solid phase extraction (SPE) column (such as an acidic silica gel column, a basic silica gel column, an activated carbon column, etc.).

[0033] Furthermore, the specific concentration process of concentrating the pretreated sample by the rotary evaporation method is as follows: transferring the pretreated sample to a rotary evaporation container, concentrating the pretreated sample, reducing the volume of the solvent, obtaining a preliminary concentrated sample, replacing the solvent of the preliminary concentrated sample, and using the rotary evaporator again for final concentration to obtain a concentrated sample.

[0034] In this example, the purified extract is transferred to a rotary evaporator and concentrated at a mild temperature (usually not exceeding 40° C.) to reduce the solvent volume and enrich the dioxins. The concentrated extract is further subjected to solvent replacement, typically from an organic solvent to a solvent-free or low-boiling point solvent (such as pentane, isooctane, etc.) that is more amenable to GC / MS analysis. A nitrogen purge apparatus is used or the rotary evaporator is used again for final concentration until a small volume of concentrate is obtained.

[0035] Furthermore, the specific separation process of transferring the concentrated sample to a high-resolution gas chromatograph for separation is as follows: the concentrated sample is transferred to an automatic injection vial, the automatic injection vial is placed in the automatic injector of the high-resolution gas chromatograph, the injection parameters are set, and the concentrated sample is heated at the injection port and carried by the carrier gas into the chromatographic column to obtain dioxin homologues.

[0036] In this embodiment, the concentrated sample is transferred to a small volume glass bottle or an automatic injection vial, and an internal standard (such as 13C-labeled dioxin homologues) is added for quantitative analysis. A suitable chromatographic column is selected, usually a capillary column, such as a fused silica capillary column, whose stationary phase may be non-polar, such as DB-5 (5% phenylmethylsiloxane). The vial containing the sample is placed in the automatic injection device, and the injection parameters, such as the injection volume (usually 1-5 μL) and the injection port temperature (usually between 250-300°C), are set. The sample is injected into the autosampler. After the inlet is heated and vaporized, it is carried into the chromatographic column by a carrier gas (such as helium). In the chromatographic column, the sample components are separated according to the degree of their interaction with the stationary phase. The separated dioxin components enter the high-resolution mass spectrometer (HRMS) in sequence. In the HRMS, the dioxin molecules are ionized and separated and detected according to their mass / charge ratio (m / z). The mass spectrometry data is processed by computer-related software, including peak identification, peak integration, isotope peak ratio analysis, etc., and the concentration of each dioxin component is calculated based on the response of the internal standard.

[0037] Verification experiment samples (with known dioxin concentrations) were prepared and subjected to the above-mentioned rotary evaporation and subsequent experiments. The above process took into account the impact of different processes on the accuracy of dioxin detection, and optimized the dioxin detection method to achieve the effect of improving the accuracy of the dioxin detection method used for waste incineration.

[0038] Furthermore, the specific analysis process for analyzing the temperature, benzopyrene concentration and instrument response factor of the chromatographic column is as follows: collecting the temperature, benzopyrene concentration and instrument response factor of the chromatographic column, analyzing the temperature, benzopyrene concentration and instrument response factor of the chromatographic column, and obtaining the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy.

[0039] In this embodiment, the specific method for obtaining the coefficient of influence of carrier gas entering the chromatographic column on the dioxin detection accuracy is as follows:

[0040]

[0041] Where, XDR represents the influence coefficient of carrier gas entering the chromatographic column on the detection accuracy of dioxins, which is used to evaluate the influence of dioxin retardation on the detection accuracy of dioxins. Several time monitoring points are set, Z = 1, 2, 3, ..., p, p represents the total number of time monitoring points, DRR Z Indicates the temperature of the chromatographic column at the Zth time monitoring point, DRR 0 represents the reference temperature of the chromatographic column, ω1 represents the weighting factor of the temperature of the chromatographic column, PAH Z represents the concentration of benzopyrene at the Zth time monitoring point, ω2 represents the weight factor of benzopyrene concentration, ERF Zrepresents the instrument response factor at the Zth time monitoring point, ω3 represents the weighting factor of the instrument response factor, and e represents a natural constant.

[0042] The temperature of the chromatographic column refers to the operating temperature of the chromatographic column, which can be directly collected by a sensor. The higher the temperature of the chromatographic column, the greater the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy.

[0043] The reference temperature of the column can be directly obtained from the database.

[0044] Benzopyrene concentrations are produced after waste incineration and are present in the samples.

[0045] Benzopyrene is a type of organic pollutant widely present in the environment. It may interfere with the detection of dioxins. This can be determined by analyzing the sample. The higher the concentration of benzopyrene, the greater the influence coefficient of the carrier gas entering the chromatographic column on the accuracy of dioxin detection.

[0046] The instrument response factor refers to the degree of response of the analytical instrument to a specific compound, that is, the proportional relationship between the signal intensity detected by the instrument and the actual compound concentration. It can be directly obtained through the database. The larger the instrument response factor, the smaller the influence of the carrier gas entering the chromatographic column on the accuracy of dioxin detection.

[0047] At lower column temperatures, the retention time of benzo[a]pyrene on the chromatographic column will increase because of its stronger interaction with the stationary phase. At low column temperatures, the peak of benzo[a]pyrene may be better separated from other compounds on the column, reducing interference. At low column temperatures, if the peak area of ​​benzo[a]pyrene increases, then at the same concentration, the detector response (peak area) will be higher, resulting in a higher instrument response factor.

[0048] In calculating the coefficient of influence of carrier gas entering the chromatographic column on dioxin detection accuracy, several key indicators—weighting factors for column temperature, benzo[a]pyrene concentration, and instrument response factor—are directly extracted from a dedicated database. The determination of these weighting factors relies on a comprehensive mapping system. For example, real-time monitored indicator values, such as column temperature, benzo[a]pyrene concentration, and instrument response factor, are converted into corresponding weighting factors. A mapping set is directly obtained from the database, linking the weighting factors for column temperature, benzo[a]pyrene concentration, and instrument response factor to these weighting factors. Specifically, this conversion process is based on the following mapping logic: After real-time data is input, the corresponding weighting factors are output through the conversion of the mapping set. For example, the real-time column temperature, benzo[a]pyrene concentration, and instrument response factor are input into the mapping set, and the corresponding weighting factors are output. This mapping can be a direct correspondence or a complex mapping where a single indicator value corresponds to multiple weighting factors. In short, this is a process of converting real-time data indicators into weight values ​​of key factors affecting component reliability prediction. The conversion rules can be either simple direct mapping or more complex many-to-one mapping.

[0049] Furthermore, the specific analysis process for analyzing the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time is as follows: the dioxin homologues separated are detected by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time; the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time are analyzed to obtain the influence coefficient of sample purification treatment on the dioxin detection accuracy.

[0050] In this embodiment, the specific method for obtaining the influence coefficient of sample purification treatment on dioxin detection accuracy is as follows:

[0051]

[0052] Where FBG represents the influence coefficient of sample purification treatment on dioxin detection accuracy, which is used to evaluate the influence of sample treatment on dioxin detection accuracy. Several sample monitoring points are set, Y = 1, 2, 3, ..., t, t represents the total number of sample monitoring points, DEE Y Indicates the purification efficiency of the purification column at the Yth sample monitoring point, SRR Y Indicates the contamination rate of PCBs to samples at the Yth sample monitoring point, SPT Yrepresents the sample processing time at the Yth sample monitoring point, α represents the weight factor of the purification efficiency of the purification column at the Yth sample monitoring point, β represents the weight factor of the contamination rate of polychlorinated biphenyls to the sample at the Yth sample monitoring point, θ represents the weight factor of the sample processing time at the Yth sample monitoring point, and e represents a natural constant.

[0053] Table 1 Example of the coefficient of influence of sample purification on dioxin detection accuracy

[0054]

[0055] When the weight factors of the purification efficiency of the purification column, the contamination rate of PCBs to the sample, and the sample processing time are 0.2, 0.3, and 0.5 respectively, Figure 2 As shown, it is an image of the influence coefficient of sample purification treatment on dioxin detection accuracy in the dioxin detection method for waste incineration provided in an embodiment of the present application. Figure 2 From the data in Table 1, it can be seen that when the contamination rate of PCBs to samples and the sample processing time remain unchanged, the greater the purification efficiency of the purification column, the greater the influence coefficient of sample purification on the dioxin detection accuracy.

[0056] The weight factors of the purification efficiency of the purification column, the weight factors of the contamination rate of polychlorinated biphenyls to the sample, and the weight factors of the sample processing time can be obtained through a network database, indicating the proportions of the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time in the coefficient of influence of the sample purification treatment on the dioxin detection accuracy. For example, based on the relationship between the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time in the historical database and the coefficient of influence of the sample purification treatment on the dioxin detection accuracy, a mapping set of the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time and their corresponding weights is established respectively. By inputting the real-time purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time, the corresponding weight factors of the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls to the sample, and the sample processing time in the mapping set are obtained.

[0057] The purification efficiency of the purification column directly affects the contamination rate of PCBs in the sample, and optimizing the sample processing time can improve the purification efficiency and recovery rate of the purification column; if the purification efficiency of the purification column is low or the processing time is inappropriate, the contamination rate of PCBs in the sample will decrease, which will affect the accuracy and reliability of the test results.

[0058] The purification efficiency of the purification column refers to the comprehensive ability of the purification column to remove various contaminants in the sample, which can be obtained from the instruction manual of the high-resolution mass spectrometer.

[0059] The contamination rate of PCBs to samples refers to the ratio of PCBs to sample contamination during the sample processing process, which can be directly obtained by gas chromatography-mass spectrometry.

[0060] Sample processing time refers to the total time required from sample collection to the final test results, including steps such as sample extraction, purification, concentration and instrument analysis, which can be obtained through system logs.

[0061] Furthermore, the specific comparison process of comparing the influence coefficient of sample purification treatment on the dioxin detection accuracy with the influence threshold of sample treatment on the dioxin detection accuracy is as follows: directly obtaining the influence threshold of sample treatment on the dioxin detection accuracy from the database, comparing the influence coefficient of sample purification treatment on the dioxin detection accuracy with the influence threshold of sample treatment on the dioxin detection accuracy; if the influence coefficient of sample purification treatment on the dioxin detection accuracy is greater than or equal to the influence threshold of sample treatment on the dioxin detection accuracy, preliminarily optimizing the dioxin detection method; if the influence coefficient of sample purification treatment on the dioxin detection accuracy is less than the influence threshold of sample treatment on the dioxin detection accuracy, marking the dioxin detection method as not affected by the sample treatment.

[0062] In this example, for dioxin testing at a waste incineration plant, the database determined that the threshold for sample processing to affect detection accuracy was 5%. During the testing process, the sample processing influence coefficient was calculated to be 7%. Because 7% is greater than 5%, preliminary optimization was required. This included adding an additional purification step using an activated carbon column to remove interfering substances such as polycyclic aromatic hydrocarbons (PAHs), and optimizing the extraction solvent from n-hexane / acetone to n-hexane / dichloromethane to improve extraction efficiency.

[0063] Preliminary optimization measures include optimizing the extraction solvent, extraction time and temperature to improve extraction efficiency, adjusting or replacing the purification column, and adding purification steps to reduce the impact of interferences.

[0064] For example, to optimize the extraction solvent, change the extraction solvent from n-hexane / dichloromethane (1:1 v / v) to n-hexane / acetone (9:1 v / v).

[0065] Optimize extraction time: Increase the extraction time from the original ten minutes to twenty minutes.

[0066] Optimize the extraction temperature: increase the extraction temperature from the original 60℃ to 90℃.

[0067] Adjust or replace the purification column or add a purification step: Use an activated carbon column to purify the extract. If the initial purification is ineffective, consider adding an additional purification step, such as using GPC (gel permeation chromatography) or replacing the purification column with a silica gel column.

[0068] Furthermore, the specific comparison process of comparing the dioxin detection accuracy assessment coefficient with the dioxin detection accuracy assessment threshold is as follows: directly obtain the dioxin detection accuracy assessment threshold from the database, compare the dioxin detection accuracy assessment coefficient with the dioxin detection accuracy assessment threshold, if the dioxin detection accuracy assessment coefficient is less than the dioxin detection accuracy assessment threshold, finally optimize the dioxin detection method; if the dioxin detection accuracy assessment coefficient is greater than or equal to the dioxin detection accuracy assessment threshold, mark the dioxin detection method as good and no optimization is required.

[0069] In this example, for example, in a dioxin test at a waste incineration plant, the database determined that the dioxin detection accuracy threshold was 90%. During the test, the calculated accuracy coefficient was 85%. This was then optimized, including adding two additional quality control samples to each test batch to monitor test variability and establishing a more rigorous data review process to ensure that all test results were independently audited.

[0070] The final optimization was to optimize the parameters of mass spectrometry.

[0071] The specific steps for optimizing the mass spectrometer parameters are as follows: adjusting the ion source temperature within a preset range; if the current ion source temperature is less than the preset range, adjusting it to the minimum value of the preset range; if the current ion source temperature is greater than the preset range, adjusting it to the maximum value of the preset range; adjusting the collision energy within a preset range; if the current collision energy is less than the preset range, adjusting it to the minimum value of the preset range; if the current collision energy is greater than the preset range, adjusting it to the maximum value of the preset range; if both the ion source temperature and the collision energy are within the preset range, no optimization is required; if at this time the dioxin detection accuracy assessment coefficient is still less than the dioxin detection accuracy assessment threshold, an alarm is issued to the relevant technical personnel to remind them to conduct a manual inspection.

[0072] Furthermore, the specific method for obtaining the dioxin detection accuracy evaluation coefficient is as follows: Where DAC represents the dioxin detection accuracy assessment coefficient, which is used to evaluate the accuracy of the dioxin detection method; XDR represents the influence coefficient of carrier gas entering the chromatographic column on the dioxin detection accuracy; FBG represents the influence coefficient of sample purification treatment on the dioxin detection accuracy; GYK represents the dioxin retardation rate; and e represents the natural constant.

[0073] In this embodiment, the dioxin blocking rate refers to the ratio of dioxin-like substances blocked or removed after various purification measures during the waste incineration process, which can be obtained through laboratory analysis.

[0074] The specific process of laboratory analysis is: directly testing the sample to obtain the dioxin concentration, and then blocking the sample from the same source to test the dioxin concentration, thereby obtaining the blocking rate.

[0075] like Figure 3 As shown, it is a structural schematic diagram of a dioxin detection system for waste incineration provided in an embodiment of the present application. The dioxin detection system for waste incineration provided in an embodiment of the present application includes: a sample collection module, a sample processing module, a data collection and analysis module, and a threshold comparison and optimization module: the sample collection module is used to collect flue gas samples from the waste incineration plant, pre-treat the flue gas samples, remove interferences, obtain pre-treated samples, and concentrate the pre-treated samples by rotary evaporation to obtain concentrated samples; the sample processing module is used to transfer the concentrated samples to a high-resolution gas chromatograph for separation, and then detect the separated dioxin homologues by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time; the data collection and analysis module is used to collect the dioxin blocking rate, the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor, and to compare the temperature of the chromatographic column, the benzopyrene concentration, and the instrument response factor. The module analyzes the influence factors of carrier gas entering the chromatographic column on the detection accuracy of dioxins, analyzes the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls on the sample, and the sample processing time, and obtains the influence coefficient of sample purification on the detection accuracy of dioxins. A comprehensive analysis is performed on the blocking rate of dioxins, the influence coefficient of carrier gas entering the chromatographic column on the detection accuracy of dioxins, and the influence coefficient of sample purification on the detection accuracy of dioxins, and obtains the dioxin detection accuracy evaluation coefficient. The module also analyzes the influence factors of carrier gas entering the chromatographic column on the detection accuracy of dioxins, and the influence coefficient of sample purification on the detection accuracy of dioxins, and obtains the dioxin detection accuracy evaluation coefficient. The module also analyzes the influence factors of sample purification on the detection accuracy of dioxins and the influence coefficient of sample purification on the detection accuracy of dioxins, and obtains the dioxin detection accuracy evaluation coefficient. The module also analyzes the influence factors of sample purification on the detection accuracy of dioxins and the dioxin detection accuracy evaluation threshold through the database, compares the influence coefficient of sample purification on the detection accuracy of dioxins with the influence threshold of sample purification on the detection accuracy of dioxins, and performs preliminary optimization of the detection method based on the threshold comparison results. The module also compares the dioxin detection accuracy evaluation coefficient with the dioxin detection accuracy evaluation threshold, and finally optimizes the detection method based on the threshold comparison results.

[0076] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0078] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0081] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A method for detecting dioxins in waste incineration, characterized in that: The following steps are involved: Collecting flue gas samples from a waste incineration plant, pre-treating the flue gas samples to remove interferences to obtain pre-treated samples, and concentrating the pre-treated samples by rotary evaporation to obtain concentrated samples; The concentrated sample is transferred to a high-resolution gas chromatograph for separation, and the separated dioxin homologues are detected by high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time; Data on dioxin blockage, column temperature, benzopyrene concentration, and instrument response factor were collected and analyzed to determine the effect of carrier gas entering the column on dioxin detection accuracy. The purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and sample processing time were analyzed to determine the effect of sample purification on dioxin detection accuracy. A comprehensive analysis of the effect of dioxin blockage, the effect of carrier gas entering the column, and the effect of sample purification on dioxin detection accuracy was performed to determine a dioxin detection accuracy assessment coefficient. The threshold value of the impact of sample processing on dioxin detection accuracy and the dioxin detection accuracy assessment threshold were directly obtained through the database. The impact coefficient of sample purification treatment on dioxin detection accuracy was compared with the threshold value of the impact of sample processing on dioxin detection accuracy. The detection method was preliminarily optimized based on the threshold comparison results. The dioxin detection accuracy assessment coefficient was compared with the dioxin detection accuracy assessment threshold. The detection method was finally optimized based on the threshold comparison results.

2. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific preprocessing process of the flue gas sample is as follows: The glass fiber filter membrane with the flue gas sample in the sampler is taken out, divided into ten small pieces, and placed in a cleaned extraction container. An organic solvent is added to the extraction container, and an ultrasonic extractor is used to extract to obtain an extract. The extract is subjected to liquid-liquid extraction, and an extractant is added to remove moisture and polar substances to obtain a pretreated sample.

3. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific concentration process of concentrating the pretreated sample by the rotary evaporation method is as follows: The pretreated sample is transferred to a rotary evaporation container, and the pretreated sample is concentrated to reduce the volume of the solvent to obtain a preliminary concentrated sample. The solvent of the preliminary concentrated sample is replaced, and the rotary evaporator is used again for final concentration to obtain a concentrated sample.

4. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific separation process of transferring the concentrated sample to high-resolution gas chromatography for separation is as follows: The concentrated sample is transferred to an automatic injection vial, which is placed in the automatic injector of a high-resolution gas chromatograph. The injection parameters are set, and the concentrated sample is heated at the injection port and carried by the carrier gas into the chromatographic column to obtain dioxin homologues.

5. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific analysis process of analyzing the temperature, benzopyrene concentration and instrument response factor of the chromatographic column is as follows: The temperature, benzopyrene concentration and instrument response factor of the chromatographic column were collected and analyzed to obtain the influence coefficient of the carrier gas entering the chromatographic column on the dioxin detection accuracy.

6. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific analysis process for analyzing the purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time is as follows: The dioxin homologues separated by high-resolution mass spectrometry were detected to obtain the purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time. The purification efficiency of the purification column, the contamination rate of the sample by polychlorinated biphenyls, and the sample processing time were analyzed to obtain the influence coefficient of sample purification treatment on the dioxin detection accuracy.

7. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific comparison process of comparing the influence coefficient of sample purification treatment on dioxin detection accuracy with the influence threshold of sample treatment on dioxin detection accuracy is as follows: The threshold value of the impact of sample processing on dioxin detection accuracy is directly obtained from the database, and the impact coefficient of sample purification processing on dioxin detection accuracy is compared with the threshold value of the impact of sample processing on dioxin detection accuracy. If the impact coefficient of sample purification processing on dioxin detection accuracy is greater than or equal to the threshold value of the impact of sample processing on dioxin detection accuracy, the dioxin detection method is preliminarily optimized. If the impact coefficient of sample purification processing on dioxin detection accuracy is less than the threshold value of the impact of sample processing on dioxin detection accuracy, the dioxin detection method is marked as not affected by sample processing.

8. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific comparison process of comparing the dioxin detection accuracy evaluation coefficient with the dioxin detection accuracy evaluation threshold is as follows: The dioxin detection accuracy assessment threshold is directly obtained from the database, and the dioxin detection accuracy assessment coefficient is compared with the dioxin detection accuracy assessment threshold. If the dioxin detection accuracy assessment coefficient is less than the dioxin detection accuracy assessment threshold, the dioxin detection method is finally optimized. If the dioxin detection accuracy assessment coefficient is greater than or equal to the dioxin detection accuracy assessment threshold, the dioxin detection method is marked as good and does not need to be optimized.

9. The dioxin detection method for waste incineration according to claim 1, characterized in that: The specific method for obtaining the dioxin detection accuracy evaluation coefficient is: Where DAC represents the dioxin detection accuracy assessment coefficient, which is used to evaluate the accuracy of the dioxin detection method; XDR represents the influence coefficient of carrier gas entering the chromatographic column on the dioxin detection accuracy; FBG represents the influence coefficient of sample purification treatment on the dioxin detection accuracy; GYK represents the dioxin retardation rate; and e represents the natural constant.

10. A dioxin detection system for waste incineration, characterized in that: It includes sample collection module, sample processing module, data collection and analysis module and threshold comparison and optimization module: Sample collection module: used to collect flue gas samples from waste incineration plants, pre-treat the flue gas samples to remove interferences, obtain pre-treated samples, and concentrate the pre-treated samples by rotary evaporation to obtain concentrated samples; Sample processing module: used to transfer the concentrated sample to a high-resolution gas chromatograph for separation, and then detect the separated dioxin homologues through high-resolution mass spectrometry to obtain the purification efficiency of the purification column, the contamination rate of PCBs in the sample, and the sample processing time; Data Collection and Analysis Module: This module collects data on dioxin blockage, column temperature, benzopyrene concentration, and instrument response factor. The module analyzes these data to determine the effect of carrier gas entering the column on dioxin detection accuracy. The module also analyzes the purification efficiency of the purification column, the contamination rate of polychlorinated biphenyls (PCBs) in the sample, and sample processing time to determine the effect of sample purification on dioxin detection accuracy. Furthermore, the module performs a comprehensive analysis of the effects of dioxin blockage, carrier gas entering the column, and sample purification on dioxin detection accuracy to determine the dioxin detection accuracy assessment coefficient. Threshold comparison and optimization module: used to directly obtain the threshold value of the impact of sample processing on dioxin detection accuracy and the dioxin detection accuracy evaluation threshold through the database, compare the impact coefficient of sample purification processing on dioxin detection accuracy with the threshold value of the impact of sample processing on dioxin detection accuracy, preliminarily optimize the detection method based on the threshold comparison results, compare the dioxin detection accuracy evaluation coefficient with the dioxin detection accuracy evaluation threshold, and finally optimize the detection method based on the threshold comparison results.

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