Odorous substance extraction apparatus

Abstract

To provide an odorous substance extraction apparatus that continuously extracts odorous substances from water to be examined and measures a concentration of the odorous substances in the water to be examined.SOLUTION: An odorous substance extraction apparatus according to an embodiment comprises: a pipe heater 4 that heats water to be examined; a concentration unit that brings an odorous substance-containing gas in which odorous substances contained in a part of the heated water to be examined are extracted, into contact with another part of the heated water to be examined to increase a concentration of the odorous substances in the water to be examined; and a gas-liquid contact device 14 that brings the concentrated water to be examined and a sample gas into gas-liquid contact and discharges the odorous substance-containing gas in which the odorous substances contained in the water to be examined are extracted to the sample gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an odorant extraction device. [Background technology]

[0002] At water purification plants, water taken from rivers, lakes, and ponds is purified to produce water that meets the water quality standards set out in the Water Supply Act and other regulations, and then supplied to the target area.Water supplied as drinking water must meet various water quality standards, and for example, specified water quality standards have been set for odorous substances that cause the odor of drinking water.

[0003] In recent years, water temperatures have been rising year by year, particularly due to global warming, creating an environment in which odor-causing algae can easily proliferate. As a result, there have been an increasing number of cases of odor problems being observed even at water purification plants where odor problems had not previously been observed.

[0004] However, to fully remove odors from water, it is necessary to detect odorous substances at very low concentrations, and conventionally, it has been necessary to detect the odorous substances using expensive analytical equipment by concentrating them over a long period of time.

[0005] Two odorous substances for which water quality standards have been set in drinking water are 2-MIB (2-methylisoborneol) and geosmin. The water quality standards for these odorous substances are set at a very low concentration of 10 ng / L, and they both have low concentrations in water and are characterized by their low tendency to volatilize into the gas phase. For this reason, quantitative detection of odorous substances is performed using expensive analytical equipment for advanced analysis.

[0006] For example, online analytical devices that automate the process from water sampling to quantitative detection of 2-MIB and geosmin have been put into practical use, but these systems are much more expensive and complex than benchtop analytical devices for manual analysis, and are not easily introduced.

[0007] Furthermore, such analyzers are, for example, online analyzers that use gas chromatography-mass spectrometry (GC / MS), which requires time to separate the target substance in a column and regenerate the column after each measurement, so measurements take time, and although they are online devices, they only output one data point per hour. In other words, they are analyzers that perform measurements once per hour (one batch).

[0008] Furthermore, GC / MS can employ a purge-and-trap method as a pretreatment, in which a liquid sample is exposed to a gas to expel (purge) target substances into the gas phase, and then the target substances are trapped using an adsorbent. The target substances desorbed from the adsorbent during pretreatment are introduced into the GC / MS for quantitative analysis. The concentration factor of target substances using the purge-and-trap method is generally said to be approximately 100-250 times. As mentioned above, because GC / MS pretreatment involves adsorption and desorption steps, it has been difficult to continuously extract and measure target substances. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2023-10559 Summary of the Invention [Problem to be solved by the invention]

[0010] The embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide an odorant extraction device that continuously extracts odorants from test water and measures the concentration of the odorants in the test water. [Means for solving the problem]

[0011] The odorant extraction device according to the embodiment comprises a heater for heating test water, a concentration section for contacting an odorant-containing gas obtained by extracting odorants contained in a portion of the heated test water with another portion of the heated test water to increase the odorant concentration of the test water, and a gas-liquid contact device for bringing the test water discharged from the concentration section into gas-liquid contact with a sample gas, and discharging an odorant-containing gas obtained by extracting odorants contained in the test water into the sample gas. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of the configuration of an odorant extraction device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the value of the dimensionless Henry's constant of 2-MIB with respect to temperature. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an odorant extraction device according to an embodiment will be described in detail with reference to the drawings. FIG. 1 is a diagram schematically illustrating an example of the configuration of an odorant extraction device according to the first embodiment. The odorant extraction device of this embodiment includes a heat exchanger 2, a pipe heater 4, a heater controller 6, a booster pump P1, an air pump P2, a concentration section, a second gas-liquid contactor 14, a dehumidifier 10, a return pump P3, temperature sensors T1-T4, flow meters F1-F3, an odorant concentration meter (gas concentration meter) 12A, and a computing device 13. The concentration section includes a first gas-liquid contactor 8 and T-shaped pipes v1-v4.

[0014] The heat exchanger 2 exchanges thermal energy between the raw water (test water) flowing into the odorant extraction device and the returned water after circulating inside the odorant extraction device. The heat exchanger 2 is of a double-pipe or plate type, and exchanges thermal energy between the fluids by passing water through them in countercurrent flow. Since the returned water after circulating inside the odorant extraction device is at a higher temperature than the raw water, thermal energy is transferred from the returned water to the raw water in the heat exchanger 2. This reduces the load on the piping heater 4, which will be described later.

[0015] The odorant extraction device of this embodiment continuously supplies odorant-containing gas to an odorant concentration meter 12A (described later). For example, when the sensitivity of the odorant concentration meter 12A is approximately 1 to 10 ppb, several tens to several hundreds of ml / min of odorant-containing gas is required, taking into account the odorant detection sensitivity. Therefore, the raw water required to obtain sufficient odorant-containing gas can reach 10 L / min. Heating a large amount of raw water to 90°C using a pipe heater 4 (described later) to extract odorants into the gas phase requires several tens of kW of thermal energy, which increases the running costs of the water quality meter. Therefore, in this embodiment, heat is recovered in the heat exchanger 2 from the raw water (hot water) returned after odorant extraction, and the raw water (test water) is preheated before the pipe heater 4, thereby reducing the energy consumed by the pipe heater 4 to several hundreds of watts to several kW. In this embodiment, the pipe heater 4 is, for example, a 3 kW heater.

[0016] The pipe heater 4 is, for example, an in-line pipe heater, and heats the pipe through which the raw water (test water) flows so that the raw water discharged from the heat exchanger 2 reaches a predetermined temperature. In the odorant extraction device of this embodiment, the raw water is heated by the pipe heater 4, thereby heating the continuously supplied test water and creating an environment in which the target odorants are easily extracted into the gas phase based on the principle of gas-liquid equilibrium.

[0017] For example, the odorous substance 2-MIB is mostly present in water in a gas-liquid equilibrium state at room temperature, with the gas-liquid concentration ratio (ratio of gas concentration to liquid concentration) being 1 / 500 in a 20°C environment, and approximately 1 / 50 even at 40°C. Therefore, the inventors conducted tests and found that by raising the temperature of the test water (raw water) to 90°C, the gas-liquid concentration ratio can be improved to approximately 3. Based on the above, in this embodiment, the pipe heater 4 preferably heats the raw water to 80°C or higher, and more preferably to 90°C or higher. In this embodiment, taking into account the temperature drop of the test water between the pipe heater 4 and the second gas-liquid contactor 14, the pipe heater 4 continuously heats the raw water to 90°C or higher (e.g., 92°C to 93°C).

[0018] The heater controller 6 controls the pipe heater 4 so that the raw water temperature becomes a predetermined temperature based on the temperature acquired from the temperature sensor T1 that detects the temperature of the raw water discharged from the pipe heater 4. The heater controller 6 may also acquire the odorant extraction temperatures (e) and (f) and control the pipe heater 4 so that the odorant extraction temperatures (e) and (f) become predetermined target values.

[0019] The booster pump P1 increases the pressure of the raw water discharged from the pipe heater 4 and outputs the water to the rectifying section. The concentrating section concentrates odorous substances in the high-pressure raw water (test water) discharged from the booster pump P1 (increases the odorous substance concentration in the test water), and discharges the concentrated test water to the second gas-liquid contactor 14.

[0020] The T-shaped pipe v1 separates the raw water flowing in from the booster pump P1 and discharges it in two directions. One of the raw water flows from the T-shaped pipe v1 and is supplied to the first gas-liquid contactor 8. The other raw water flows into the T-shaped pipe v2.

[0021] The first gas-liquid contactor 8 brings high-pressure raw water (a part of the test water) discharged from one outlet of the T-shaped pipe v1 into contact with gas (sample gas), continuously extracts odorous substances from the raw water into the air, and discharges the odorous substance-containing gas. In this embodiment, air, for example, can be used as the sample gas.

[0022] The gas-liquid contact method may be, for example, bubbling, in which a gas (sample gas) is pumped into the liquid by an air pump P2 via a T-shaped pipe v3, a spray, in which a liquid is sprayed into the gas, or a membrane. Bubbling may be performed using a porous medium, or microbubbles may be formed using a Venturi tube or the like. Spraying may be performed using a single-fluid nozzle or a two-fluid nozzle. For example, a hydrophobic membrane may be used to efficiently achieve gas-liquid contact.

[0023] Furthermore, in the odorant extraction apparatus of this embodiment, the first gas-liquid contact tank 8 may have a fine bubble generator (not shown). A Venturi tube or the like can be used as the fine bubble generator. The fine bubble generator generates fine bubbles of, for example, 1000 nm or less. By generating fine bubbles in the first gas-liquid contact tank 8, 2-MIB, which tends to be hydrophobic, is adsorbed by the bubbles and becomes more likely to volatilize, thereby improving the gas-liquid contact efficiency. If the gas-liquid contact efficiency in the first gas-liquid contact tank 8 is improved, the gas residence time in the first gas-liquid contact tank 8 can be shortened, and the first gas-liquid contact tank 8 can be made smaller.

[0024] The raw water from which odorous substances have been extracted in the first gas-liquid contactor 8 is sent to the heat exchanger 2 by the return pump P3 via the T-pipe v4, passes through the heat exchanger 2 and is then discharged. The temperature sensor T3 detects the environmental temperature (extraction temperature of odorous substances) where gas-liquid contact is performed in the first gas-liquid contactor 8, and supplies the detected value to the arithmetic unit 13.

[0025] The odorant-containing gas discharged from the first gas-liquid contactor 8 flows into the T-piping v2. The T-piping v2 mixes the fluids that flow in from two directions and discharges the mixture in one direction. The raw water (another part of the test water) discharged from the other outlet of the T-pipe v1 and the odorant-containing gas discharged from the first gas-liquid contactor 8 flow into the T-pipe v2. When the odorant-containing gas comes into contact with the raw water (another part of the test water) in the T-pipe v2, at least a portion of the odorants in the odorant-containing gas dissolves in the raw water (another part of the test water). As a result, the odorant concentration in the raw water discharged from the T-pipe v2 becomes higher than that of the original raw water. The T-pipe v2 may be provided with an outlet for discharging the odorant-containing gas after the odorants have been extracted. The raw water discharged from the T-pipe v2 is supplied to the second gas-liquid contactor 14.

[0026] The second gas-liquid contactor 14 has the same configuration as the first gas-liquid contactor 8. The second gas-liquid contactor 14 brings the raw water discharged from the outlet of the T-shaped pipe v2 into contact with a gas (sample gas), continuously extracts odorous substances from the raw water into the air, and discharges the odorous substance-containing gas. In this embodiment, air, for example, can be used as the sample gas.

[0027] The gas-liquid contact method may be, for example, bubbling, in which a gas (sample gas) is pumped into the liquid by an air pump P2 via a T-shaped pipe v3, a spray, in which a liquid is sprayed into the gas, or a membrane. Bubbling may be performed using a porous medium, or microbubbles may be formed using a Venturi tube or the like. Spraying may be performed using a single-fluid nozzle or a two-fluid nozzle. For example, a hydrophobic membrane may be used to efficiently achieve gas-liquid contact.

[0028] Furthermore, in the odorant extraction apparatus of this embodiment, the second gas-liquid contactor 14 may have a fine bubble generator (not shown). A Venturi tube or the like can be used as the fine bubble generator. The fine bubble generator generates fine bubbles of, for example, 1000 nm or less. By generating fine bubbles in the second gas-liquid contactor 14, the hydrophobic 2-MIB is adsorbed by the bubbles and becomes more volatile, thereby improving the gas-liquid contact efficiency. If the gas-liquid contact efficiency in the second gas-liquid contactor 14 is improved, the gas residence time in the second gas-liquid contactor 14 can be shortened, and the second gas-liquid contactor 14 can be made smaller.

[0029] The flow rate of the sample gas delivered by the air pump P2 to the first gas-liquid contactor 8 and the second gas-liquid contactor 14 is measured by a flow meter F1. The sample gas discharged from the air pump P2 flows into a T-shaped pipe v3 and is discharged in two directions from the T-shaped pipe v3. The sample gas discharged from one outlet of the T-shaped pipe v3 is supplied to the first gas-liquid contactor 8, and the sample gas discharged from the other outlet of the T-shaped pipe v3 is supplied to the second gas-liquid contactor 14. The flow meter F1 measures the flow rate of the sample gas flowing into the T-shaped pipe v3, and therefore the measurement value of the flow meter F1 is the sum of the flow rate of the sample gas delivered to the first gas-liquid contactor 8 and the flow rate of the sample gas delivered to the second gas-liquid contactor 14.

[0030] The raw water from which odorous substances have been extracted in the second gas-liquid contactor 14 is sent to the heat exchanger 2 by the return pump P3 via the T-pipe v4, passes through the heat exchanger 2 and is then discharged. The raw water from which odorants have been extracted in the first gas-liquid contactor 8 and the original from which odorants have been extracted in the second gas-liquid contactor 14 each flow into the T-shaped pipe v4. The T-shaped pipe v4 combines the raw water flowing in from two directions and discharges the combined water to the heat exchanger 2.

[0031] The dehumidifier 10 dehumidifies and discharges the odorant-containing gas discharged from the second gas-liquid contactor 14. The odorant-containing gas is dehumidified by the dehumidifier 10 because the odorant-containing gas discharged from the second gas-liquid contactor 14 contains a large amount of water vapor, and the water vapor interferes with measurement when measuring trace values ​​with the odorant concentration meter 12A located downstream.

[0032] For example, when raw water containing 10 ng / L of dissolved 2-MIB is subjected to gas-liquid equilibrium in an environment of 90°C, 2-MIB is extracted into the gas phase. 3 ) can be extracted. If the temperature of this odorant-containing gas drops before it reaches the odorant concentration meter 12A (described later), the condensation of water vapor will have a negative effect on the measurement of odorant concentration. Furthermore, although the odorant concentration meter 12A can be a semiconductor type, a type with a modified quartz crystal oscillator, or an infrared absorption type, the presence of a large amount of water vapor will cause noise and a decrease in sensitivity in all of these types.

[0033] In order to accurately measure the concentration of odorants in the odorant concentration meter 12A, it is desirable to supply odorant-containing gas at a constant temperature and humidity. 3 ) and supplying an odorant-containing gas, the odorant concentration meter 12A as described above can generally operate stably.

[0034] Considering the above, in order to maintain a constant humidity level in the odorant-containing gas, the odorant extraction device of this embodiment is equipped with, for example, a cooling-type dehumidifier 10. Here, for example, a membrane-type dehumidifier is not recommended because it adsorbs trace amounts of odorants, causing a decrease in accuracy. Furthermore, even in a cooling-type dehumidifier, a certain proportion of odorants may be absorbed into the condensed water, but because sufficient time is not ensured within the dehumidifier to reach gas-liquid equilibrium, most of the odorants may remain in the gas phase.

[0035] The odorant-containing gas discharged from the dehumidifier 10 is supplied to the odorant concentration meter 12A. The temperature sensor T2 detects the temperature of the odorant-containing gas discharged from the dehumidifier 10, i.e., the odorant-containing gas supplied to the odorant concentration meter 12A.

[0036] The odorant concentration meter 12A measures the odorant concentration in the odorant-containing gas discharged from the dehumidifier 10 and supplies the measurement value to the calculation device 13. The odorant concentration meter 12A may be, for example, a semiconductor concentration meter with detection capabilities on the order of ppm. Furthermore, some odorant concentration meters, such as laser concentration meters, are capable of detecting 1 to 10 ppb. Alternatively, the odorant concentration meter 12A may be a quartz crystal oscillator modified with a sensitive film or MOF (metal organic framework) and measure odors using the frequency change. The odorant extraction device of this embodiment assumes that a laser concentration meter can detect 1 ppb. Therefore, when the 2-MIB concentration in water is 10 ng / L, the odorant-containing gas supplied to the odorant concentration meter 12A has a 2-MIB concentration of 1 ppb or more. For example, the flow rate of raw water used for odorant extraction is calculated based on the dimensionless Henry's constant (described below) and the gas flow rate required for the odorant concentration meter 12A.

[0037] The arithmetic device 13 includes, for example, at least one processor and a memory storing programs executed by the processor, and can realize various functions by software. The arithmetic device 13 can calculate the odorant concentration (a') in the raw water (test water flowing into the piping heater 4) before odorant extraction using the odorant concentration (d) in the gas measured by the odorant concentration meter 12A, the odorant concentration (x) in the raw water after odorant extraction, the flow rate (b) of the raw water used for odorant extraction (flow rate of the test water flowing into the piping heater 4) detected by the flow meter F2, the flow rate (c) of the odorant-containing gas measured by the flow meter F3, and the odorant concentration rate (y = odorant concentration before concentration / odorant concentration after concentration) according to the following formula:

[0038] a = (b + cH) / (bx)…(1) x=d / H…(2) a´=a×y…(3) In the above formula, a is the concentration of odorants in the raw water after the odorants have been concentrated (the raw water that has flowed into the second gas-liquid contactor 14), and H is a dimensionless Henry's constant that is preset according to the extraction temperature of the odorants.

[0039] The calculation device 13 can perform the calculations of the above equations (1)-(3) using the value of the concentration ratio y and the value of the dimensionless Henry's constant H that have been calculated in advance. The calculation device 13 may calculate the value of the concentration ratio y using the environmental temperature (extraction temperature of odorous substances) (e) where gas-liquid contact is performed in the first gas-liquid contactor 8. The calculation device 13 may also calculate the value of the dimensionless Henry's constant from the value of the environmental temperature (extraction temperature of odorous substances) (f) in the second gas-liquid contactor 14 detected by the temperature sensor T4.

[0040] The odorous substances specified in the water quality standards are 2-MIB and geosmin, both of which have low concentrations in water and are not easily volatilized into the gas phase. Furthermore, the water quality standards for these odorous substances have a very low concentration of 10 ng / L.

[0041] The volatilization of a substance into the gas phase can be expressed using the dimensionless Henry's constant, which indicates the relationship between gas-liquid equilibrium. For example, the dimensionless Henry's constant for 2-MIB at 20°C is 0.002. In other words, at gas-liquid equilibrium, the ratio of the 2-MIB concentration in the air to the 2-MIB concentration in water is 1:500. Therefore, when water with an odorant concentration of 10 ng / L, as specified in the water quality standards, reaches gas-liquid equilibrium at 20°C, the 2-MIB concentration in the gas phase will be 0.02 ng / L.

[0042] Therefore, if 2-MIB is extracted into the gas phase to detect its concentration in the gas phase, the target substance must be detected in an environment where the odorant is even more dilute. For this reason, in the purge-and-trap method, for example, 2-MIB is first absorbed into an adsorbent such as activated carbon after gas-liquid contact, and then eluted and concentrated to a detectable level. Furthermore, this method requires batch processing because of the use of an adsorbent, making it difficult to continuously extract odorants.

[0043] On the other hand, the inventors of the present invention have focused on the temperature dependency of the dimensionless Henry's constant. FIG. 2 is a diagram showing an example of the value of the dimensionless Henry's constant of 2-MIB with respect to temperature. For example, the dimensionless Henry's constant for 2-MIB in an environment of 39°C is 0.02. This means that a gas concentration 10 times higher can be obtained in an environment of 39°C than in an environment of 20°C. Based on this, the inventors of the present application predicted the dimensionless Henry's constant in environments with further increased temperatures using a prediction formula derived from the relationship between environmental temperature and the dimensionless Henry's constant shown in FIG. 2 . The results showed that the dimensionless Henry's constant for 2-MIB was 1.35 in an environment of 80°C, 2.8 in an environment of 87°C, and 3.82 in an environment of 90°C. The computing device 13 uses the above-mentioned dimensionless Henry's constant prediction formula to calculate the dimensionless Henry's constant at the environmental temperature in the second gas-liquid contactor 14, and can then calculate the odorant concentration in the raw water using the above-mentioned formulas (1) to (3).

[0044] As described above, the odorant extraction device of this embodiment can continuously extract gas containing odorants, and the odorant concentration in the odorant-containing gas can be continuously measured by the odorant concentration meter 12A placed downstream of the dehumidifier 10. Furthermore, since the odorant extraction device of this embodiment can continuously extract high-concentration odorant-containing gas, it is possible to detect the odorant concentration in raw water without using expensive and complicated equipment such as a mass spectrometer. That is, according to this embodiment, it is possible to provide an odorant extraction device that continuously extracts odorants in test water and measures the concentration of odorants in the test water.

[0045] In the odorant extraction device of this embodiment, the concentration section is not limited to the configuration shown in Fig. 1. For example, the concentration section does not have to include the T-shaped pipe v1. In that case, the odorant extraction device may be configured to include at least a second pipe heater that heats the incoming raw water and discharges it, and a second booster pump that pressurizes the raw water discharged from the second pipe heater and discharges it, supplying the raw water discharged from the booster pump P1 to the first gas-liquid contactor 8, and supplying the odorant-containing gas discharged from the first gas-liquid contactor 8 and the raw water discharged from the second booster pump to the T-shaped pipe v2, and discharging the raw water in which odorants have been concentrated from the T-shaped pipe v2. Even in this case, the same effects as those of the odorant extraction device shown in Fig. 1 can be obtained.

[0046] 1, the sample gas discharged from the air pump P2 is discharged in two directions through the T-shaped pipe v3 and supplied to each of the first gas-liquid contactor 8 and the second gas-liquid contactor 14, but the T-shaped pipe v3 may be omitted and an air pump may be provided to deliver the sample gas to the first gas-liquid contactor 8 and an air pump to deliver the sample gas to the second gas-liquid contactor 14. Even in this case, the same effects as those of the odorous substance extraction apparatus shown in FIG.

[0047] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0048] For example, in the above-described embodiment, the odorant extraction device is configured to include one concentrating section, but the odorant extraction device may be configured to include multiple concentrating sections. In this case, the multiple concentrating sections are connected in series between the booster pump P1 and the second gas-liquid contactor 14, and the test water discharged from the T-shaped pipe v2 of the previous concentrating section is supplied to the T-shaped pipe v1 of the next concentrating section. With an odorant extraction device equipped with multiple concentrating sections, the odorant-containing gas extracted from a portion of the test water by the first gas-liquid contactor 8 is repeatedly brought into contact with another portion of the test water to concentrate the odorants in the test water. This makes it possible to further increase the odorant concentration in the test water supplied to the second gas-liquid contactor 14, and to continuously extract high-concentration odorant-containing gas from test water in which high concentrations of odorants have been dissolved in the second gas-liquid contactor 14. [Explanation of symbols]

[0049] 2...heat exchanger, 4...piping heater, 6...heater controller, 8...first gas-liquid contactor, 10...dehumidifier, 12A...odor substance concentration meter, 13...calculating device, 14...second gas-liquid contactor, F1-F3...flow meter, T1-T4...temperature sensors, P1...booster pump, P2...air pump, P3...return pump, v1-v4...T-piping

Claims

1. a heater for heating the test water; a concentration section that brings an odorant-containing gas obtained by extracting odorants contained in a portion of the heated test water into contact with another portion of the heated test water, thereby increasing the odorant concentration of the test water; an odorant extraction device comprising: a gas-liquid contactor that brings the test water discharged from the concentration section into gas-liquid contact with a sample gas, and discharges an odorant-containing gas in which odorants contained in the test water are extracted into the sample gas.

2. The concentration unit includes a first gas-liquid contactor that brings a portion of the heated test water into gas-liquid contact with a sample gas, and discharges an odorant-containing gas in which odorants contained in the portion of the test water are extracted into the sample gas; a T-shaped pipe into which the odorant-containing gas discharged from the first gas-liquid contactor and the other part of the test water flow, and into which at least a part of the odorant-containing gas is dissolved to discharge the other part of the test water having an increased odorant concentration; The odorant extraction device according to claim 1, comprising:

3. The odorant extraction device according to claim 1 , comprising a plurality of the concentration sections connected in series between the heater and the gas-liquid contactor.

4. a dehumidifier for dehumidifying the odorous substance-containing gas; 2. The odorant extraction device according to claim 1, further comprising: a calculation device that calculates the odorant concentration in the test water before the odorant extraction, using the flow rate and odorant concentration of the odorant-containing gas discharged from the dehumidifier and the flow rate of the test water flowing into the heater.

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