JP3708750B2 - Dioxin simple continuous analysis method and equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention uses gas chromatography to detect and simultaneously measure (monitor) dioxins and furans (hereinafter sometimes referred to as DXNs) contained in the atmosphere, exhaust gas, soil, or combustion ash. In particular, the present invention relates to a system and a device for monitoring the state of occurrence of dioxins in exhaust gas from a waste incineration facility or factory.
[0002]
[Prior art]
DXNs in the exhaust gas from garbage incineration facilities and factory plants are subject to high resolution gas chromatography mass spectrometry (hereinafter referred to as GC / MS) in accordance with the Ministry of Health and Welfare's “Manual for Standard Measurement and Analysis of Dioxins in Waste Disposal” etc. It has begun to be used and analyzed. In the mass spectrometry, a concentrated solution obtained by extracting almost all DXNs in a sample through a large number of acid treatments, extraction treatments, concentration treatments and the like from air, exhaust gas, and soil samples is quantitatively analyzed by high resolution GC / MS. Trial and error is performed so that DXNs in the exhaust gas are minimized by adjusting the operating conditions and exhaust conditions of the waste incineration facility, factory plant, and the like using the data obtained by the quantitative analysis.
[0003]
[Problems to be solved by the invention]
In the above-described prior art, various sample extraction processes require a time of about one week at the earliest, and GC / MS analysis takes several hours. That is, after the sample is sent to the analysis maker, the analysis result data is usually obtained only after a minimum of about two weeks. For example, when DXNs exceeding the reference value are generated under a predetermined operating condition, the details are found for the first time after about two weeks, and thus DXNs exceeding the reference value have been continuously generated.
[0004]
In addition, since the conventional technique continues to work for more than one week, there are extremely problems in the health and safety of instruments, humans, etc., and there has been a demand for a method and apparatus that can easily and quickly measure and evaluate DXNs.
[0005]
The object of the present invention is to easily and quickly extract dioxins and furans contained in the atmosphere, exhaust gas, soil, or combustion ash, and measure DXNs in the sample. It is to provide a dioxin monitoring system.
[0006]
[Means for Solving the Problems]
The object of the present invention is to detect dioxins and furans in the atmosphere, exhaust gas, soil, combustion ash, etc. using gas chromatography and continuously measure them in the dioxins or furans. It is solved by a simple continuous analysis method of dioxins that performs TEQ (toxic equivalence) of all dioxins and furans by quantifying specific one or two kinds of the above.
[0007]
That is, the present invention detects dioxins and furans in a sample gas using a gas chromatography, and in the dioxin simple continuous analysis method for continuous measurement, other dioxins and furans contained in the sample gas. The amount of 1 type and / or 2 types of dioxins and furans having a detection peak apart from the gas chromatographic detection peak (retention time greatly differing) is determined in advance by gas chromatography. A dioxin simple continuous analysis method that calculates TEQ (toxic equivalent) of all dioxins and furans from a calibration curve showing the correlation between the content of the compound and the TEQ (toxic equivalent) of all dioxins and furans is there.
[0008]
What are the 1 and / or 2 dioxins and furans that have a detection peak apart from the gas chromatographic detection peaks of other dioxins and furans contained in the sample gas (retention time varies greatly)? , Octachlorodibenzo-p-dioxin and / or octachlorodibenzofuran having 8 chlorine atoms.
[0009]
In addition, the present invention introduces a sample gas from the flue and captures interfering components that interfere with the measurement of the total dioxins, furans and low boiling point compounds in the sample gas. A step of adsorbing to the collecting agent; a step of increasing the temperature of the collecting agent and passing an inert gas so that the interfering component adsorbed on the collecting agent is desorbed from the collecting agent and removed out of the system; , Increasing the collector temperature while passing an inert gas, octachlorodibenzo-p-dioxin having a detection peak away from the gas chromatographic detection peaks of other dioxins and furans in the sample gas, and / or a step of desorbing the measured component of the octa-chloro-dibenzofuran from scavenger, the measurement component desorbed from the scavenger to flow into a gas chromatography , The amount of steps and other dioxins and furans octa chlorodibenzo -p- dioxins and / or octa-chloro dibenzofuran with detected peaks away from the gas chromatographic detection peaks in the sample gas and measuring the concentration Is determined by gas chromatography, and from the calibration curve showing the correlation between the content of the compound obtained in advance and the TEQ (toxic equivalent) of all dioxins and furans, the TEQ of all dioxins and furans It is a dioxin simple continuous analysis method comprising a step of obtaining (toxic equivalent amount).
[0010]
Furthermore, in the present invention, a sample provided with a switching valve for introducing an inert gas into the gas flow path in order from the upstream side of the gas flow path for introducing the sample gas from the flue, and a heating means capable of changing the heating temperature. A collecting means for disposing a collecting agent that adsorbs a disturbing component that interferes with the measurement of TEQ of all dioxins and furans including all dioxins and furans and low boiling point compounds in the gas; A switching valve that discharges the disturbing component desorbed from the collecting agent of the collecting means by adjusting the heating temperature of the heating means, and the sample gas from the collecting agent of the collecting means by adjusting the heating temperature of the heating means. other octa chlorodibenzo -p- dioxins and / or octa-chlorodibenzo off with detected peaks away from the gas chromatographic detection peak of dioxins and furans And gas chromatography for introducing the measurement component obtained by desorbing down, all dioxins from the calibration curve showing the correlation between the TEQ content and total dioxins and furans of the measurement component (toxic equivalents) And a simple dioxin continuous analysis apparatus including a calculation means for calculating TEQ (toxic equivalent amount) of furans.
[0011]
FIG. 6 shows a correlation graph (calibration curve) of the one or two types of DXN and TEQ prepared in advance.
JP-A-9-243601 and JP-A-10-153591 describe an invention in which the correlation between chlorobenzene, chlorophenol and DXN is obtained and the concentration of DXN is obtained from this correlation. The prior invention calculates the DXN concentration using the concentration of a substance other than DXN as a reference value, whereas the present invention measures DXN itself. Since it is more reliable to measure a part of DXN than to measure an alternative substance as reference value data, the measurement method of the present invention is a better method.
[0012]
[Action]
In the present invention, specific one or two kinds of DXNs each having 20 or more isomers contained in the atmosphere or exhaust gas are gas chromatographed (low resolution GC / MS or SAW / GC) for several seconds. It is a system that calculates total toxicity equivalent (TEQ) by detecting within ~ several minutes and measures it almost simultaneously (real time).
[0013]
When samples in the atmosphere and exhaust gas are directly analyzed using gas chromatography, substances other than DXNs and DXN isomers having the same retention time as DXNs contained in the sample interfere with each other. It is difficult to completely separate DXNs. However, by analyzing one or two types of DXN having a detection peak at a distance (retention time is greatly different) from other DXN gas chromatography detection peaks, It was found that TEQ can be displayed instantaneously from the correlation graph (calibration curve) of TEQ.
[0014]
In other words, the inventors obtained all DXNs (including TEQ) in ash and exhaust gas containing dioxins using a high-resolution GC / MS method in accordance with the Ministry of Health and Welfare's “Dioxin Standard Measurement and Analysis Manual for Waste Disposal” and the like. As a result of investigating the correlation between TEQ and TEQ, most DXNs in the analysis of real gases such as air and exhaust gas are proportional to TEQ determined by high resolution GC / MS. I found out that
[0015]
However, most DXNs interfere with detection peaks as described above, and are difficult to separate. For example, as shown in FIG. 7, when the DXN peak and the interfering substance peak are adjacent or overlapped, the DXN peak value is interfered by the interfering substance peak value or buried in the interfering substance peak value. , Accurate DXN peak values may not be obtained.
[0016]
In addition, as a result of reviewing examples of DXN peaks that were separated relatively well and data obtained when focusing on specific well-separated DXN, most DXNs having several tens of types have quantitative values analyzed by gas chromatography. It was found to be proportional to TEQ quantified by high resolution GC / MS.
Thus, the present inventors have found that DXNs having 8 chlorine numbers have higher boiling points than DXNs having 7 chlorines, and therefore are easily separated from other DXNs and coexisting substances other than DXNs.
[0017]
One or two types of detection peaks at low-resolution GC / MS or SAW / GC (Surface Acoustic Wave: Surface Acoustic Wave GC) that are far from the gas chromatographic detection peaks of DXNs (retention time is greatly different) DXN is octachlorodibenzo-p-dioxin and / or octachlorodibenzofuran. These substances have a boiling point higher than those of other DXNs, and since there are almost no substances having peaks after them in the air or exhaust gas, they can be easily separated by gas chromatography.
[0018]
Calibration by TEQ quantified by one or two types of DXN and high resolution GC / MS by quantifying one or two types of DXN having a detection peak at a distance from the gas chromatographic detection peak of other DXNs If a line (eg, FIG. 6) is created, the TEQ can be calculated immediately.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The flow (four steps) of the embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows an overall flow diagram of a simple continuous analysis system for dioxins according to an embodiment of the present invention. A pre-filter 2 for removing impurities in the gas, a valve 3 for supplying helium from the helium bomb 4, and DXNs in the gas are collected in the gas flow path on the downstream side of the flue 1. For collecting the collector 5 with the electric furnace 6, the SAW / GC 12 direction for measuring the DXNs, the valve 7 for guiding the gas, the pump 8 for sending the gas to the flow meter 9, the gas for discharging out of the system A valve 10 and a pump 11 are sequentially provided. The gas channel can be heated by the heaters 13 and 14.
[0020]
In the flow of the simple continuous analysis system for dioxins having the above configuration, first, FIG. 3 shows a sampling process of the sample gas for DXN measurement. The sample gas is introduced from the flue 1 using the pump 8. At this time, the dust is removed from the gas by the pre-filter 2, passes through the valve 3, and DXNs in the gas are held in the collection agent 5. The gas that has passed through the collection agent 5 passes through the valve 7 and is discharged by the pump 8.
[0021]
Next, as shown in FIG. 5, the temperature of the collection agent 5 is increased by the electric furnace 6 in order to remove components that interfere with the measurement of DXNs in the sample gas adsorbed on the collection agent 5. Then, the valve 3 is switched, and helium is guided from the helium cylinder 4 into the sample gas and sent to the collecting agent 5 whose temperature has risen. At this time, interfering components (low boiling point compounds) held in the scavenger 5 are exhausted by the pump 11 that has passed through the valve 10 together with helium gas.
[0022]
When the temperature of the collecting agent 5 is further increased, the valve 10 is switched in the SAW / GC 12 direction as shown in FIG. 4, and DXN in the sample gas is measured by the SAW / GC 12.
When the DXN measurement is completed, the valve 10 is switched to the pump 11 side as shown in FIG. 5, and the interfering component (high boiling point compound) held in the scavenger 5 is removed.
The temperature of the collection agent in each process of the system is shown in FIG.
[0023]
Example 1
Using a dioxin monitor system using SAW / GC12 having the above-described configuration, DXNs in exhaust gas from a garbage incineration treatment plant were simultaneously measured. During sampling, the gas duct from the flue 1 to the sample inlet of the SAW / GC 12 was kept at 300 ° C. or higher using the heater 13.
[0024]
The sample sampling time of SAW / GC12 is 10 seconds, the measurement time is 20 seconds, and octachlorosibenzo-p-dioxin (hereinafter referred to as O8CCD) is measured for a total of 30 seconds. TEQ was calculated using a calibration curve of O8CCD and TEQ and displayed on the display of a personal computer.
As a result, the TEQ in the sample gas was 0.74 (ng-TEQ / Nm3). Using this system, DXNs can be monitored (simultaneous measurement) at intervals of several minutes.
[0025]
Example 2
DXNs of exhaust gas at the same waste incineration plant as in Example 1 were simultaneously measured using a dioxin monitor system using low resolution GC / MS instead of SAW / GC 12 of the system shown in FIG. At the time of sampling, the gas duct from the flue 1 to the sample outlet was kept at 300 ° C. or higher using the heater 13.
[0026]
The sample sampling time of GC / MS is 10 minutes, the measurement time is 10 minutes, and octachlorodibenzo-p-dioxin (hereinafter referred to as O8CCD) is measured in a total of 20 minutes. TEQ was calculated using a calibration curve and displayed on a personal computer display.
[0027]
As a result, the sample gas TEQ was 0.71 (ng-TEQ / Nm3). Using this system, DXNs can be monitored (simultaneous measurement) at intervals of several tens of minutes.
[0028]
Comparative Example 1
Using the conventional high-resolution GC / MS (high-resolution gas chromatograph mass spectrometry based on the Ministry of Health and Welfare's “Manual for Standard Measurement and Analysis of Dioxins in Waste Disposal” etc.), the exhaust gas from the same waste incineration plant as in Example 1 is used. DXNs were measured.
The sample gas extraction process and the GC / MS measurement took 11 days. As a result, the sample gas TEQ was 0.74 (ng-TEQ / Nm3).
[0029]
【The invention's effect】
According to the method of the present invention, TEQs of DXNs can be measured simultaneously (in real time) without erroneous detection, and can be used as a dioxin simple continuous measurement system.
[Brief description of the drawings]
FIG. 1 shows a flow of a dioxin simple continuous measurement system according to an embodiment of the present invention.
FIG. 2 shows the relationship between the temperature of the collecting agent in each step of the system of FIG.
FIG. 3 is a diagram showing a gas sampling process of the system of FIG. 1;
FIG. 4 is a diagram showing a DXN measurement process in the gas of the system of FIG. 1;
FIG. 5 shows a disturbing component removal process and a clean-up process of the system of FIG.
FIG. 6 is a diagram showing a calibration curve showing a correlation between DXN and TEQ in the dioxin simple continuous measurement system according to the embodiment of the present invention.
FIG. 7 is a diagram showing a peak state of an interfering substance affecting a DXN peak.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flue 2 Pre-filter 3 Valve 4 Helium cylinder 5 Collection agent 6 Electric furnace 7 Valve 8 Pump 9 Flowmeter 10 Valve 11 Pump 12 SAW / GC
13 Heater (Insulator) 14 Heater (Insulator)

Claims (3)

Dioxins and furans in the sample gas are detected using gas chromatography, and in the dioxin simple continuous analysis method that continuously measures, the gas chromatography detection peaks of other dioxins and furans contained in the sample gas Quantifies the amount of octachlorodibenzo-p-dioxin and / or octachlorodibenzofuran having a detection peak at a distance by gas chromatography, thereby determining the content of the compound and the total dioxins and furans determined in advance. A simple dioxin continuous analysis method characterized in that TEQ (toxic equivalent) of all dioxins and furans is obtained from a calibration curve showing a correlation with TEQ (toxic equivalent). A step of introducing a sample gas from the flue and adsorbing an interfering component that interferes with the measurement of TEQ of all dioxins and furans including all dioxins and furans and low-boiling compounds in the sample gas to a collecting agent. And raising the temperature of the scavenger and passing an inert gas so that the interfering components adsorbed on the scavenger are desorbed from the scavenger and removed from the system, and the inert gas is passed through. While increasing the temperature of the collection agent, octachlorodibenzo-p-dioxin and / or octachlorodibenzofuran having a detection peak away from the gas chromatographic detection peaks of other dioxins and furans in the sample gas. A step of desorbing the measurement component from the collection agent, and the concentration of the measurement component desorbed from the collection agent is introduced into the gas chromatography. Process and, quantified by the amount of gas chromatography other dioxins and furans octa chlorodibenzo -p- dioxins and / or octa-chloro dibenzofuran with detected peaks away from the gas chromatographic detection peaks in the sample gas to From the calibration curve showing the correlation between the content of the compound obtained in advance and the TEQ (toxic equivalent) of all dioxins and furans, the TEQ (toxic equivalent) of all dioxins and furans A simple continuous analysis method for dioxins characterized by comprising In order from the upstream side of the gas flow path for introducing the sample gas from the flue, all dioxins in the sample gas, comprising a switching valve for introducing an inert gas into the gas flow path, heating means capable of changing the heating temperature, and A collecting means in which a collecting agent that adsorbs a disturbing component that interferes with the measurement of TEQ of all dioxins and furans including furans and low-boiling compounds is disposed on the collecting agent, and heating temperature adjustment of the heating means A switching valve that discharges the interfering component desorbed from the collecting agent of the collecting means by the outside, and other dioxins and furans in the sample gas from the collecting agent of the collecting means by adjusting the heating temperature of the heating means. oct chlorodibenzo -p- dioxins and / or octa-chloro dibenzofuran with detected peaks away from the gas chromatographic detection peak classes by desorption resulting et al From the calibration curve showing the correlation between the content of the measured components and the TEQ (toxic equivalent) of all dioxins and furans, and the TEQ (toxicity of all dioxins and furans). A simple dioxin continuous analysis apparatus comprising a calculation means for calculating an equivalent amount).

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